@phdthesis{Heinz2001, author = {Heinz, Werner J.}, title = {Identifikation und Charakterisierung von PHR3, einem zu der PHR/GAS-Familie homologen Gen bei Candida albicans}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-1179719}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2001}, abstract = {Es konnte mit PHR3 bei Candida albicans ein drittes GAS-homologes Gen nachgewiesen werden. Dieses weist {\"u}berzeugende {\"U}bereinstimmungen der Nuklein- und Aminos{\"a}urensequenz und mit der fehlenden GPI-Verankerungsstelle und der pH-konstitutiven Expression auch interessante Unterschiede zu den bisher bekannten Genen der PHR-Familie auf. Eine funktionelle Homologie zu den weiteren PHR-Genen bei Candida albicans konnte nicht belegt werden. Es sind bisher in verschiedenen Spezies mehrere homologe Gene dieser Familie nachgewiesen worden. So sind auch bei Candida albicans weitere m{\"o}glich und die endg{\"u}ltige Zahl der PHR-Gene wird erst nach Abschluß des Candida albicans-Genomprojektes bestimmt werden k{\"o}nnen. Der Zweck mehrerer homologer Gene ist insbesondere f{\"u}r die bei unterschiedlichen pH-Werten vorliegenden Proteine Phr1p und Phr2p noch nicht bekannt. Eine m{\"o}gliche Erkl{\"a}rung ist, dass ihre Translation auf unterschiedliche Weise die Expression anderer Gene oder die Prozessierung und Funktion von Proteinen beeinflusst. Eine solche feine Regulation von Wachstums- und Virulenzfaktoren und somit eine Anpassung an Umweltbedingungen und Infektionswege ist f{\"u}r die Pathogenit{\"a}t von Candida albicans von Bedeutung. Die spezifischen Faktoren f{\"u}r die Induktion von PHR3 sind, sollte eine differenzierte Regulation vorliegen, dagegen ebenso wenig wie f{\"u}r GAS4, als n{\"a}hestes verwandtes Gen, und f{\"u}r die weiteren GAS-Gene bekannt. Zum Nachweis einer solchen signalspezifischen Transkription sind Experimente mit anderen Versuchsanordnungen, mit welchen sich komplexere Milieus und Infektionswege untersuchen lassen, wie DNA-Chips oder induktionsabh{\"a}ngige Signalkassetten (Morschh{\"a}user et al., 1999; Staib et al., 1999) hilfreich. Da eine fehlende C-terminale Region bei GAS1 zur Sekretion eines vergr{\"o}ßerten Proteins mit Hypermannosylierung der serinreichen Region f{\"u}hrt (Popolo et Vai, 1998), erscheint auch eine extrazellul{\"a}re Funktion von Phr3p, welches dieses hydrophobe 3' Ende nativ nicht besitzt, m{\"o}glich. Dabei ist eine zu Phr1p und Phr2p {\"a}hnliche oder gleiche enzymatische Funktion, welche in Diskussion 112 unterschiedlichen Kompartimenten oder von unterschiedlicher Lokalisation aus den Aufbau der Zellwand beeinflusst, denkbar.}, language = {de} } @phdthesis{Kaasch2002, author = {Kaasch, Achim J.}, title = {Charakterisierung und Lokalisation der Toxoplasma gondii Katalase: Peroxisomen in Apicomplexa?}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-6493}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2002}, abstract = {Toxoplasma gondii ist ein obligat intrazellul{\"a}rer, einzelliger Parasit aus dem Phylum der Apicomplexa. Infektionen des Menschen mit T. gondii verlaufen meist subklinisch. Nach einer Infektion persistiert der Erreger f{\"u}r viele Jahre in Hirn- und Muskelgewebe. Durch Reaktivierung des Erregers, z. B. durch eine Immunschw{\"a}chekrankheit oder unter Immunsuppression, kann eine Enzephalitis mit septischer Streuung entstehen. Eine diaplazentare Infektion f{\"u}hrt zur Fetopathia toxoplasmotica mit Fr{\"u}h- und Totgeburten oder zu der typischen enzephalitischen Trias aus Chorioretinitis, Hydrozephalus und zerebralen Verkalkungen. Ein Mechanismus, der es T. gondii erm{\"o}glicht im Wirtsorganismus zu {\"u}berleben, ist die ungew{\"o}hnlich hohe Widerstandsf{\"a}higkeit gegen{\"u}ber freien Radikalen. Die wichtigste Quelle f{\"u}r freie Radikale bei der Abwehrreaktion des Wirtsorganismus ist Wasserstoffperoxid (H2O2 ). Es wird beim sogenannten „respiratory burst" von Makrophagen freigesetzt, diffundiert dann durch biologische Membranen und sch{\"a}digt DNA, Lipide und Proteine durch Zerfall in Sauerstoffradikale. Außerdem entsteht (H2O2 ) auch bei normalen Stoffwechselvorg{\"a}ngen in den Persoxisomen der Zelle. Das Enzym Katalase (EC 1.11.1.6) wandelt zweiWasserstoffperoxidmolek{\"u}le in Wasser und Sauerstoff um und eliminiert somit toxisches Wasserstoffperoxid. Katalase liegt zumeist in spezialisierten Zellorganellen, den Peroxisomen oder Microbodies, vor. Dort dient es zum Abbau von bei metabolischen Prozessen entstehendem Wasserstoffperoxid. Im Rahmen der vorliegenden Arbeit wurde die Katalase von Toxoplasma gondii kloniert und charakterisiert. Die Klonierung von T. gondii Katalase cDNA ergab ein Protein mit 502 Aminos{\"a}uren und einem errechneten Gewicht von 57.2 kDa mit starker Homologie zu anderen eukaryontischen Katalasen. Ein polyklonales Antiserum gegen ein GST-Fusionsprotein zeigte imWestern-blot eine Bande bei ungef{\"a}hr 63 kDa. Die Immunfluoreszenz zeigte ein vesikul{\"a}res Kompartiment im vorderen Ende des Parasiten. Dieses kann von anderen Zellorganellen (Mikronemen, Rhoptrien, Granula densa und dem Apikoplast) durch doppelte Immunfluoreszenzmarkierung unterschieden werden. Zytochemisch k{\"o}nnen Katalasen durch die DAB-Pr{\"a}zipitationstechnik nachgewiesen werden. Hier zeigten sich vesikul{\"a}re Strukturen vor dem Nukleus in der Lichtmikroskopie und runde, spezifische Pr{\"a}zipitate mit einem Durchmesser von 100 bis 300nm in der Elektronenmikroskopie. Am C-terminus der T. gondii Katalase findet sich ein „peroxisomales Targeting Signal" (PTS1) in den letzten 3 Aminos{\"a}uren (-AKM). Die Expression der vollst{\"a}ndigen Katalase in CHO-Zellen resultiert in einer peroxisomalen Lokalisation, w{\"a}hrend ein Konstrukt ohne die letzten 3 Aminos{\"a}uren im Zytosol verbleibt. Wird das PTS1 mit einem Reporterprotein (Chloramphenicol-Acetyltransferase) fusioniert, wechselt dessen Lokalisation vom Zytosol zu den Peroxisomen. Damit wurde gezeigt, daß das PTS1 der T. gondii Katalase in einem heterologen System sowohl im Kontext der Katalase als auch eines Reporterproteins den Import in Peroxisomen vermitteln kann. Diese Ergebnisse sind die ersten Hinweise auf Peroxisomen in einem Parasiten der Apikomplexa. Zugleich ist T. gondii, evolutionsbiologisch gesehen, der bisher niedrigste Eukaryont in dem bisher Peroxisomen nachgewiesen wurden.}, language = {de} } @phdthesis{Valenza2003, author = {Valenza, Giuseppe}, title = {Kulturunabh{\"a}ngige Analyse der subgingivalen bakteriellen Flora bei Hypophosphatasiepatienten}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-7094}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2003}, abstract = {Kurzfassung in deutsch Ziel dieser Studie war die Analyse der bakteriellen Diversit{\"a}t der subgingivalen Plaque bei einem Hypophosphatasiepatientenkollektiv durch Anwendung der 16S rRNA Technologie. Das Kollektiv bestand aus sieben m{\"a}nnlichen Patienten mit einer infantil-juvenilen Hypophosphatasie. Es sollten mikrobiologische Evidenzen f{\"u}r oder gegen die Hypothese einer fr{\"u}hen Parodontitis bei Hypophosphatasiepatienten gewonnen werden. Subgingivale Plaqueproben wurden von jedem Patienten entnommen. Anschließend folgte die DNA Extraktion aus den Plaqueproben und die Amplifikation der 16S rRNA Gene mittels zweier verschiedener universeller Primer-Paare: 27f/519r; 515f/1525r. Die PCR-Produkte wurden kloniert und sequenziert. Dann folgte ein Vergleich der Sequenzen mit der Genbank Database durch den BLAST-Server des National Center for Biotechnology Information (NBCI, Bethesda, MD, USA). Insgesamt wurden zwei verschiedene 16S rRNA Genbanken erstellt und 101 Klone pro Genbank identifiziert. Mit der 27f/519r PCR wurden 15 bakterielle Familien, mit der 515f/1525r PCR 10 bakterielle Familien identifiziert. 66 Phylotypen wurden in der 27f/519r Genbank identifiziert, 41 in der 515f/1525r Genbank. Der Coverage war 50\% in der 27f/519r Genbank und 73\% in der zweiten Genbank. In allgemeinen zeigte sich ein hoher Anzahl der Keime der physiologischen Plaqueflora (Streptococcus sp. und Actinomyces sp.), dagegen kamen putative Parodontalpathogene wie Porphyromonas gingivalis, Filifactor alocis, Tannerella forsythensis, Campylobacter rectus niemals vor. Die Analyse der bakteriellen Diversit{\"a}t der subgingivalen Plaque erbrachte eine deutlich andere Zusammensetzung im Vergleich zu Padodontitispatienten. Es zeigte sich somit keine mikrobiologische Evidenz f{\"u}r eine Parodontitis bei dem Hypophosphatasiepatientenkollektiv.}, language = {de} } @phdthesis{Metter2003, author = {Metter, Nicole}, title = {Klonierung und Sequenzierung der zur Lipopolysaccharid-Biosynthese notwendigen Gene von Legionella pneumophila Serogruppe 1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-6500}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2003}, abstract = {Durch den monoklonalen Antik{\"o}rper mAk 2625, der ein Epitop im Bereich des LPS bindet, konnte f{\"u}r den virulenten Stamm RC1 von Legionella pneumophila Serogruppe 1 Subgruppe OLDA eine spontane instabile LPS-Mutante isoliert werden. Die Mutante zeigte eine Phasenvariation des Epitops, sowie einen Verlust der Virulenz und Serumresistenz. Um Zugang zum molekularen Mechanismus der Phasenvariation des LPS zu bekommen, erfolgte zun{\"a}chst die Komplementierung der stabilen mAk 2625-negativen LPS-Mutante 137 mit der Genbank des zugeh{\"o}rigen Wildtyps. Die Komplementierung und Rekonstitution des mAk 2625-Epitops gelang mit einem 3 kb langen klonierten genomischen Fragment. Die Mutation des Stammes 137 konnte einer Deletion eines Cytosin-Restes im sp{\"a}ter benannten Orf 8 zugeschrieben werden. Das Protein welches sich aus der Sequenz von Orf 8 ableitet, zeigt Homologien zu bakteriellen Methyltransferasen. Mit Sonden, welche sich aus den klonierten Fragmenten ableiteten, konnte eine Genbank des Stammes RC1 nach LPS-Biosynthese-Genen durchsucht werden. Auf diese Weise gelang die Identifizierung einer 32661 bp langen Region des Genoms von Legionella pneumophila, die 30 m{\"o}gliche offenen Leseraster (Orfs) enth{\"a}lt. Einige dieser Orfs zeigen signifikante Homologien zu bekannten Gensequenzen der Core- und O-Antigen-Biosynthese. Der molekulare Mechanismus der Phasenvariation konnte jedoch durch diese Untersuchungen nicht entschl{\"u}sselt werden. Erst anschließende Untersuchungen zeigten, daß es sich um ein 30 kb langes instabiles genetisches Element handelt, das vermutlich auf einen Phagenursprung zur{\"u}ckgeht.}, language = {de} } @phdthesis{Beland2002, author = {Beland, Heidi}, title = {Molekulare Charakterisierung eines Tropomodulin-Homologen des Fuchsbandwurms E. multilocularis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-6168}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2002}, abstract = {Zusammenfassend konnte im Rahmen dieser Arbeit erstmals ein Tropomodulin- homologer Faktor aus einem Plathelminthen auf molekularer Ebene charakterisiert werden. Zudem wurde die Interaktion des kodierten Faktors mit einem k{\"u}rzlich isolierten Tropomyosin- Homologen aus E. multilocularis nachgewiesen. Basierend auf diesen Daten ist es nun m{\"o}glich, die biologische Signifikanz der Interaktion von Elp mit EmTY weiterf{\"u}hrend zu untersuchen. Sollte sich in diesen Studien herausstellen, daß der ERM- Faktor Elp in der Tat mit dem Tropomodulin- Tropomyosin- System der E. multilocularis- Zelle interferiert, k{\"o}nnte dies ein wichtiger Beitrag zu unserem Verst{\"a}ndnis des signaltransduktorischen Geschehens zwischen der Plasmamembran und dem Zytoskelett bei E. multilocularis sein.}, language = {de} } @phdthesis{Schmidt2010, author = {Schmidt, Katrin}, title = {Untersuchung zum in vitro Wachstumsverhalten ausgesuchter MRSA-St{\"a}mme}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-55570}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {In dieser Arbeit wurde das in vitro Wachstumsverhalten ausgesuchter MRSA in Konkurrenz zu Bakterien der Standortflora unter Optimalbedingungen und unter Mangelbedingungen getestet. Es l{\"a}sst sich f{\"u}r alle getesteten MRSA-St{\"a}mme zusammenfassend sagen, dass ihre klinische Pr{\"a}valenz nicht mit dem Wachstum in vitro korreliert, d.h. das h{\"a}ufige Spa-Typen nicht besser unter unseren Versuchbedingungen gewachsen sind als seltene. In vitro konnte kein verdr{\"a}ngendes Wachstum des Methicillin sensiblen S. aureus gegen{\"u}ber den resistenten St{\"a}mme beobachtet werden. Vielmehr gelingt es den MRSA-St{\"a}mmen, ein Wachstumsgemisch zu ihrem Vorteil zu beeinflussen, indem sie die getesteten anderen Mikroorganismen (S. epidermidis, S. cerivisiae) im Wachstum hemmen, mit Ausnahme von E. faecium. Die Arbeit beleuchtet die Schwierigkeiten der Identifizierung von probiotischen Arten zur Verdr{\"a}ngung eines MRSA. In Zukunft sollte vielleicht an der Optimierung von in vitro Systemen gearbeitet werden (in vitro Organkulturen) oder Tiermodelle verwendet werden. Den Transmissionsunterschieden und der Tenazit{\"a}t sind weiterhin Aufmerksamkeit zu widmen. Wie in der Literatur beschrieben ist es zum Verst{\"a}ndnis des Wachstumsverhal-tens der resistenten St{\"a}mme wichtig zu wissen, auf welchen molekularbiologischen Grundlagen die Resistenz beruht, da eine einzelne Site-Mutation zus{\"a}tzliche Resistenzen bedeuten und einen eventuellen Wachstumsnachteil wieder ausgleichen kann. Im Klinikalltag scheinen sich die MRSA-St{\"a}mme auszubreiten, die den Wachstumsnachteil bereits ausgeglichen haben, beziehungsweise deren Methicillinresistenz keinen Wachstumsnachteil bedeutet.}, subject = {MRSA}, language = {de} } @article{SlaninaHeblingHaucketal.2012, author = {Slanina, Heiko and Hebling, Sabrina and Hauck, Christoph R. and Schubert-Unkmeir, Alexandra}, title = {Cell Invasion by Neisseria meningitidis Requires a Functional Interplay between the Focal Adhesion Kinase, Src and Cortactin}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-75354}, year = {2012}, abstract = {Entry of Neisseria meningitidis (the meningococcus) into human brain microvascular endothelial cells (HBMEC) is mediated by fibronectin or vitronectin bound to the surface protein Opc forming a bridge to the respective integrins. This interaction leads to cytoskeletal rearrangement and uptake of meningococci. In this study, we determined that the focal adhesion kinase (FAK), which directly associates with integrins, is involved in integrin-mediated internalization of N. meningitidis in HBMEC. Inhibition of FAK activity by the specific FAK inhibitor PF 573882 reduced Opc-mediated invasion of HBMEC more than 90\%. Moreover, overexpression of FAK mutants that were either impaired in the kinase activity or were not capable of autophosphorylation or overexpression of the dominant-negative version of FAK (FRNK) blocked integrin-mediated internalization of N. meningitidis. Importantly, FAK-deficient fibroblasts were significantly less invaded by N. meningitidis. Furthermore, N. meningitidis induced tyrosine phosphorylation of several host proteins including the FAK/Src complex substrate cortactin. Inhibition of cortactin expression by siRNA silencing and mutation of critical amino acid residues within cortactin, that encompass Arp2/3 association and dynamin binding, significantly reduced meningococcal invasion into eukaryotic cells suggesting that both domains are critical for efficient uptake of N. meningitidis into eukaryotic cells. Together, these results indicate that N. meningitidis exploits the integrin signal pathway for its entry and that FAK mediates the transfer of signals from activated integrins to the cytoskeleton. A cooperative interplay between FAK, Src and cortactin then enables endocytosis of N. meningitidis into host cells.}, subject = {Medizin}, language = {en} } @phdthesis{Pawlik2013, author = {Pawlik, Marie-Christin}, title = {Gene expression in the human pathogen Neisseria meningitidis: Adaptation to serum exposure and zinc limitation}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-78758}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Neisseria meningitidis is a facultative human pathogen that occasionally shows strong resistance against serum complement exposure. Previously described factors that mediate meningococcal serum resistance are for example the capsule, LPS sialylation, and expression of the factor H binding protein. I aimed for identification of novel serum resistance factors, thereby following two approaches, i) the analysis of the impact of global regulators of gene expression on serum resistance; and ii) a comparative analysis of closely related strains differing in serum resistance. (i) Of six meningococcal global regulators of gene expression studied, only mutation of the zinc uptake regulator Zur reduced complement deposition on meningococci. Little was known about meningococcal Zur and regulatory processes in response to zinc. I therefore elucidated the yet unidentified meningococcal Zur regulon comparing the transcriptional response of the N. meningitidis strain MC58 under zinc-rich and zinc-deficient conditions using a common reference design of microarray analysis. The meningococcal Zur regulon comprises 17 genes, of which 15 genes were repressed and two genes were activated at high zinc condition. Amongst the Zur-repressed genes were genes involved in zinc uptake, tRNA modification, and ribosomal assembly. A 23 bp meningococcal consensus Zur binding motif (Zur box) with a conserved central palindrome was established (TGTTATDNHATAACA) and detected in the promoter region of all regulated transcriptional units (genes/operons). In vitro binding of meningococcal Zur to the Zur box of three selected genes was shown for the first time using EMSAs. Binding of meningococcal Zur to DNA depended specifically on zinc, and mutations in the palindromic sequence constrained Zur binding to the DNA motif. ii) Three closely related strains of ST-41/44 cc from invasive disease and carriage which differed in their resistance to serum complement exposure were analysed to identify novel mediators of serum resistance. I compared the strains' gene content by microarray analysis which revealed six genes being present in both carrier isolates, but absent in the invasive isolate. Four of them are part of two Islands of horizontally transferred DNA, i.e. IHT-B and -C. The working group furthermore applied a comprehensive screening assay, a transcriptome and a proteome analysis leading to identification of three target proteins. I contributed to establish the role of these three proteins in serum resistance: The adhesin Opc mediates serum resistance by binding of vitronectin, a negative regulator of the complement system; the hypothetical protein NMB0865 slightly contributes to serum resistance by a yet unknown mechanism; and NspA, recently identified to bind the negative complement regulator factor H, led to considerable reduced complement-mediated killing.}, subject = {Komplement }, language = {en} } @phdthesis{Danhof2013, author = {Danhof, Sophia}, title = {Molekulare Untersuchung der Interaktion von Neutrophil Extracellular Traps mit dem humanen Pathogen Neisseria meningitidis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85231}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2013}, abstract = {Neisseria meningitidis ist ein wichtiger Erreger von Meningitis und Sepsis insbesondere bei jungen Menschen, gleichzeitig sind hohe Raten asymptomatischen Tr{\"a}gertums bekannt. Als die Virulenz beg{\"u}nstigende Faktoren wurden unter anderem die Kapsel, Pili, {\"a}ußere Membranvesikel (OMV) und Lipopolysaccharid (LPS) identifiziert, die es dem Erreger erleichtern, das menschliche Immunsystem zu {\"u}berwinden. Dabei war bisher die Rolle von Neutrophil Extracellular Traps (NETs) als neu beschriebene Komponente der angeborenen Immunantwort nicht untersucht worden. NETs stellen spinnennetzartige DNA-Strukturen mit globul{\"a}ren Proteindom{\"a}nen dar, die aus neutrophilen Granulozyten entstehen und als antimikrobiell gelten. Ziel dieser Arbeit war es, die Wirkung von NETs auf Meningokokken zu charakterisieren und m{\"o}gliche Resistenzmechanismen der Bakterien zu identifizieren. In den vorliegenden Versuchen konnte gezeigt werden, dass Meningokokken an NETs binden und durch diese in ihrer Proliferation gehemmt werden. Eine Lokalisation der Bakterien an die NETs konnte dargestellt werden, LPS und Pili wurden als wichtige Strukturen f{\"u}r die Vermittlung der NET-Bindung identifiziert. OMVs zeigten sich als protektiv gegen{\"u}ber dem Einfluss der NETs, indem sie die Bindung der Erreger an die NETs blockierten. Wenig empfindlich zeigten sich die Bakterien gegen{\"u}ber Histonen als den quantitativ bedeutsamsten NET-Proteinen. Meningokokken sch{\"u}tzen sich gegen{\"u}ber dem Einfluss der NETs durch Ausbildung von Kapsel und LPS mit intakter Phosphoethanolamin-Modifikation. Ebenso vermitteln zwei Cathelicidin-Resistenzgene den Bakterien einen {\"U}berlebensvorteil. Keine Rolle bei der NET-Resistenz spielten die untersuchten Effluxmechanismen. Neuere Untersuchungen von Lappann et al. indentifizierten Meningokokken und OMVs als potente NET-Induktoren. Damit k{\"o}nnten durch die relativ NET-resistenten Mikroorganismen andere Abwehrmechanismen der Neutrophilen konterkariert werden und eine Immunevasion beg{\"u}nstigt werden. Genauere Untersuchungen diesbez{\"u}glich stehen noch aus.}, subject = {Neisseria meningitidis}, language = {de} } @article{EliasHeuschmannSchmittetal.2013, author = {Elias, Johannes and Heuschmann, Peter U. and Schmitt, Corinna and Eckhardt, Frithjof and Boehm, Hartmut and Maier, Sebastian and Kolb-M{\"a}urer, Annette and Riedmiller, Hubertus and M{\"u}llges, Wolfgang and Weisser, Christoph and Wunder, Christian and Frosch, Matthias and Vogel, Ulrich}, title = {Prevalence dependent calibration of a predictive model for nasal carriage of methicillin-resistant Staphylococcus aureus}, series = {BMC Infectious Diseases}, journal = {BMC Infectious Diseases}, doi = {10.1186/1471-2334-13-111}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-96091}, year = {2013}, abstract = {Background Published models predicting nasal colonization with Methicillin-resistant Staphylococcus aureus among hospital admissions predominantly focus on separation of carriers from non-carriers and are frequently evaluated using measures of discrimination. In contrast, accurate estimation of carriage probability, which may inform decisions regarding treatment and infection control, is rarely assessed. Furthermore, no published models adjust for MRSA prevalence. Methods Using logistic regression, a scoring system (values from 0 to 200) predicting nasal carriage of MRSA was created using a derivation cohort of 3091 individuals admitted to a European tertiary referral center between July 2007 and March 2008. The expected positive predictive value of a rapid diagnostic test (GeneOhm, Becton \& Dickinson Co.) was modeled using non-linear regression according to score. Models were validated on a second cohort from the same hospital consisting of 2043 patients admitted between August 2008 and January 2012. Our suggested correction score for prevalence was proportional to the log-transformed odds ratio between cohorts. Calibration before and after correction, i.e. accurate classification into arbitrary strata, was assessed with the Hosmer-Lemeshow-Test. Results Treating culture as reference, the rapid diagnostic test had positive predictive values of 64.8\% and 54.0\% in derivation and internal validation corhorts with prevalences of 2.3\% and 1.7\%, respectively. In addition to low prevalence, low positive predictive values were due to high proportion (> 66\%) of mecA-negative Staphylococcus aureus among false positive results. Age, nursing home residence, admission through the medical emergency department, and ICD-10-GM admission diagnoses starting with "A" or "J" were associated with MRSA carriage and were thus included in the scoring system, which showed good calibration in predicting probability of carriage and the rapid diagnostic test's expected positive predictive value. Calibration for both probability of carriage and expected positive predictive value in the internal validation cohort was improved by applying the correction score. Conclusions Given a set of patient parameters, the presented models accurately predict a) probability of nasal carriage of MRSA and b) a rapid diagnostic test's expected positive predictive value. While the former can inform decisions regarding empiric antibiotic treatment and infection control, the latter can influence choice of screening method.}, language = {en} } @article{EliasFindlowBorrowetal.2013, author = {Elias, Johannes and Findlow, Jamie and Borrow, Ray and Tremmel, Angelika and Frosch, Matthias and Vogel, Ulrich}, title = {Persistence of antibodies in laboratory staff immunized with quadrivalent meningococcal polysaccharide vaccine}, series = {Journal of Occupational Medicine and Toxicology}, journal = {Journal of Occupational Medicine and Toxicology}, doi = {10.1186/1745-6673-8-4}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-95953}, year = {2013}, abstract = {Background Occupational exposure to live meningococci can potentially cause invasive meningococcal disease in laboratory staff. While, until recently, immunization with quadrivalent polysaccharide vaccine represented one cornerstone of protection, data on long-term persistence of antibodies in adults remain scarce. Methods We analyzed the relationship of antibody levels and time following quadrivalent polysaccharide vaccination (Mencevax® ACWY, GlaxoSmithKline) in a cross-sectional sample of 20 laboratory workers vaccinated at ages between 16.4 to 40.7 years from Germany. Sera were obtained 0.4 to 158.5 (median 35.3) months after vaccination. At the time of sampling, laboratory workers had been regularly exposed to meningococci for periods between 3.2 to 163.8 (median 41.2) months. Serum bactericidal assay (SBA) with rabbit complement and a microsphere-based flow analysis method were used to determine bactericidal titers and concentrations of IgG, respectively, against serogroups A, C, W135, and Y. Decay of antibodies was modeled using linear regression. Protective levels were defined as SBA titers ≥ 8. Results Half-lives of SBA titers against serogroups A, C, W135, and Y were estimated at 27.4, 21.9, 18.8, and 28.0 months, respectively. Average durations of protection were estimated at 183.9, 182.0, 114.6, and 216.4 months, respectively. Inter-individual variation was high; using lower margins of 95\% prediction intervals, minimal durations of protection against serogroups A, C, W135 and Y were estimated at 33.5, 24.6, 0.0, and 55.1 months, respectively. The proportion of staff with protective SBA titers against W135 (65.0\%) was significantly lower than proportions protected against A (95.0\%), C (94.7\%), and Y (95.0\%). Consistently, geometric mean titer (97.0) and geometric mean concentration of IgG (2.1 μg/ml) was lowest against serogroup W135. SBA titers in a subset of individuals with incomplete protection rose to ≥ 128 (≥ 8 fold) after reimmunization with a quadrivalent glycoconjugate vaccine. Conclusions The average duration of protection following immunization with a quadrivalent polysaccharide vaccine in adults was ≥ 115 months regardless of serogroup. A substantial proportion (approximately 23\% according to our decay model) of adult vaccinees may not retain protection against serogroup W135 for five years, the time suggested for reimmunization.}, language = {en} } @phdthesis{Muenstermann2022, author = {M{\"u}nstermann, Marcel}, title = {The roles of the anaphylatoxin receptors during invasive disease as well as mucosal colonization caused by \(Neisseria\) \(meningitidis\)}, doi = {10.25972/OPUS-26975}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-269759}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {The human specific gram-negative bacterium Neisseria meningitidis (Nme, meningococci) is a common colonizer of the upper respiratory tract. Upon becoming invasive, Nme can cause meningitis and life-threatening sepsis. The most important immune defense mechanism in invasive meningococcal disease (IMD) is the complement mediated killing of bacteria. The complement cascade is activated through different pathogen associated patterns and finally leads to the lysis of the bacteria by the membrane attack complex. In addition to the direct bacterial killing, the complement system is also an important player in different inflammatory processes. A hallmark of IMD is an overreaction of the immune system and the release of the potent anaphylatoxins C3a and C5a by the complement system is an important factor hereby. There are three anaphylatoxin receptors (ATRs), the C3aR, the C5aR1 and the C5aR2, capable of detecting these anaphylatoxins. It has already been shown that blocking the ATR C5aR1 strongly benefitted the outcome of IMD in a murine sepsis model. However, the roles of ATRs C3aR and C5aR2 in IMD are still unclear. This work aims to analyze the role of these ATRs in meningococcal sepsis and to identify possible underlying mechanisms. Furthermore, a possible involvement of the complement system, the ATRs and the type II CRISPR/Cas system on nasopharyngeal colonization is analyzed. In vivo depletion experiments showed that without neutrophils or monocytes/macrophages the complement system alone was not able to clear a low dose Nme infection, which highlights the importance of cellular components in IMD. Analyzing the role of the ATRs in knock-out mice with high dose Nme infections, revealed that the lack of C5aR2, like the lack of C5aR1, was beneficial for the outcome of meningococcal induced sepsis. In contrast, the lack of C3aR in knock-out mice was detrimental. The positive outcome associated with the C5aRs could be reproduced by using an antagonist against both C5aRs or an antagonist specifically against C5aR1 in WT mice. These findings are giving hope to future therapeutic applications. Next, a possible contribution of neutrophils to this positive outcome was analyzed. Absence of C5aR1 led to a decrease of degranulation by neutrophils in a murine whole blood model, while the other ATRs showed no effect. Neutrophil analysis in human whole blood, on the other hand, revealed a reduced oxidative burst and IL-8 secretion upon inhibition of all three ATRs. A functional difference between the C5aRs and the C3aR in neutrophils was observed in phagocytosis, which was reduced upon C3aR inhibition, but was unaltered with C5aR1 or C5aR2 inhibition. Possible underlying mechanisms in the phosphorylation of ERK1/2 were analyzed in bone marrow derived macrophages isolated from ATR knock-out mice. The later phosphorylation of ERK1/2 in macrophages without C5aR1 or C5aR2 expression might explain, why blocking the C5aRs is beneficial for the outcome of IMD in mice. In contrast to these findings, the colonization of the nasopharynx in huCEACAM 1 expressing mice by Nme did not seem to depend on the Complement system factors C3 and C5 nor the ATRs. Additionally, no difference in the colonization could be observed in this model using Nme mutants lacking different parts of the type 2 CRISPR/Cas system. Conclusively, this work highlights the importance of the complement system, the ATRs and the cellular components in IMD. Contrariwise, these factors did not play a role in the analyzed nasopharyngeal infection model. The beneficial effects of C5aR1 and C5aR2 lack/inhibition in IMD might have medicinal applications, which could support the standard therapies of IMD in the future.}, subject = {Anaphylatoxine}, language = {en} } @phdthesis{Mordhorst2009, author = {Mordhorst, Ines Louise}, title = {Phylogenetische und funktionelle Analysen zur Kapsel O-Acetyltransferase NeuO von Escherichia coli K1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-47880}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Escherichia coli ist ein Kommensale des menschlichen und tierischen Gastrointestinaltraktes. Einige E. coli-St{\"a}mme sind in der Lage, extraintestinale Erkrankungen beim Menschen wie Harnwegsinfekte, Neugeborenen-Meningitis und Sepsis, sowie beim Tier avi{\"a}re Coliseptik{\"a}mien, hervorzurufen. Ein wichtiger Virulenzfaktor des Bakteriums ist dabei die aus \&\#945;-2,8-verkn{\"u}pften Sialins{\"a}uremonomeren aufgebaute K1-Kapsel, die phasenvariabel mit einer hohen Frequenz O-acetyliert werden kann. Im Jahr 2005 konnte gezeigt werden, dass es sich bei dem f{\"u}r die O-Acetylierung verantwortlichen Enzym um die O-Acetyltransferase NeuO handelt, die von dem K1-spezifischen Prophagen CUS-3 codiert wird. Die Verteilung von neuO in der E. coli K1-Population sowie die funktionelle Relevanz der K1-Kapsel O-Acetylierung f{\"u}r das Bakterium waren zu Beginn der vorliegenden Arbeit weitestgehend unklar. Eine E. coli K1-Stammsammlung mit 183 Isolaten wurde aufgebaut. Die E. coli K1-Isolate stammten sowohl aus Stuhlproben gesunder Freiwilliger, humanen Harnwegsinfekten, humanen invasiven Erkrankungen (Neugeborenen-Meningitis und Bakteri{\"a}mie) und aus an Coliseptik{\"a}mie erkrankten V{\"o}geln. Die Isolate der E. coli K1-Stammsammlung wurden mit der Multilokus-Sequenztypisierung (MLST) typisiert. Es konnten 39 Sequenztypen (ST) sowie f{\"u}nf Sequenztyp-Komplexe (STC) identifiziert werden. Bei dem mit Abstand h{\"a}ufigsten STC handelte es sich um den STC95, dem 80 St{\"a}mme (44\%) angeh{\"o}rten. Insgesamt 103 der 183 E. coli K1-St{\"a}mme waren neuO-positiv (56\%). Das Gen wurde in 78 (98\%) der STC95-Isolate, aber nur in 25 (24\%) der 103 nicht-STC95-St{\"a}mme gefunden. NeuO war also mit dem STC95 assoziiert. {\"U}ber Sequenzanalysen des CUS-3-Prophagen konnten CUS-3-Genotypen bestimmt werden. Die Gruppierung der CUS-3-Genotypen und der E. coli K1-ST sowie der anschließende Vergleich beider Gruppierungen miteinander offenbarte eine Segregation der Prophagen-Genotypen entsprechend der ST. Daher legen die in dieser Arbeit ermittelten Ergebnisse eine Koevolution des Phagen mit seinem Wirt nahe. Einige humane und avi{\"a}re E. coli K1-Isolate waren weder auf Basis der MLST bzw. der CUS-3-Genotypisierung noch anhand des Vorhandenseins verschiedener, mit extraintestinal-pathogenen E. coli-assoziierter Gene voneinander unterscheidbar, was die Hypothese einer zoonotischen Transmission dieser St{\"a}mme unterst{\"u}tzt. In den in dieser Arbeit durchgef{\"u}hrten funktionellen Analysen konnte weder ein Effekt der NeuO-vermittelten E. coli K1-Kapsel O-Acetylierung auf die F{\"a}higkeit der Bakterien an humane mikrovaskul{\"a}re Gehirnendothelzellen zu adh{\"a}rieren oder in diese zu invadieren, noch auf die in vivo-Virulenz der Bakterien im H{\"u}hnermodell beobachtet werden. Die K1-Kapsel O-Acetylierung verringerte die in vivo-Kolonisierung des H{\"u}hner-Gastrointestinaltraktes und die in vitro-Biofilmbildung durch das Bakterium, wohingegen sie die Austrocknungsresistenz von E. coli K1 erh{\"o}hte. M{\"o}glicherweise dient die phasenvariable neuO-Expression und damit die E. coli K1-Kapsel O-Acetylierung der Anpassung des Bakteriums an wechselnde Umweltbedingungen.}, subject = {Escherichia coli}, language = {de} } @article{AldejohannWiesePosseltGastmeieretal.2022, author = {Aldejohann, Alexander Maximilian and Wiese-Posselt, Miriam and Gastmeier, Petra and Kurzai, Oliver}, title = {Expert recommendations for prevention and management of Candida auris transmission}, series = {Mycoses}, volume = {65}, journal = {Mycoses}, number = {6}, doi = {10.1111/myc.13445}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318570}, pages = {590 -- 598}, year = {2022}, abstract = {Candida auris was first described as a yeast pathogen in 2009. Since then, the species has emerged worldwide. In contrast to most other Candida spp., C. auris frequently exhibits multi-drug resistance and is readily transmitted in hospital settings. While most detections so far are from colonised patients, C. auris does cause superficial and life-threatening invasive infections. During management of the first documented C. auris transmission in a German hospital, experts from the National Reference Centers for Invasive Fungal Infections (NRZMyk) and the National Reference Center for Surveillance of Nosocomial Infections screened available literature and integrated available knowledge on infection prevention and C. auris epidemiology and biology to enable optimal containment. Relevant recommendations developed during this process are summarised in this guidance document, intended to assist in management of C. auris transmission and potential outbreak situations. Rapid and effective measures to contain C. auris spread require a multi-disciplinary approach that includes clinical specialists of the affected unit, nursing staff, hospital hygiene, diagnostic microbiology, cleaning staff, hospital management and experts in diagnostic mycology / fungal infections. Action should be initiated in a step-wise process and relevant interventions differ between management of singular C. auris colonised / infected patients and detection of potential C. auris transmission or nosocomial outbreaks.}, language = {en} } @article{SuratVogelWiegeringetal.2021, author = {Surat, G{\"u}zin and Vogel, Ulrich and Wiegering, Armin and Germer, Christoph-Thomas and Lock, Johan Friso}, title = {Defining the scope of antimicrobial stewardship interventions on the prescription quality of antibiotics for surgical intra-abdominal infections}, series = {Antibiotics}, volume = {10}, journal = {Antibiotics}, number = {1}, issn = {2079-6382}, doi = {10.3390/antibiotics10010073}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-223034}, year = {2021}, abstract = {Background: The aim of this study was to assess the impact of antimicrobial stewardship interventions on surgical antibiotic prescription behavior in the management of non-elective surgical intra-abdominal infections, focusing on postoperative antibiotic use, including the appropriateness of indications. Methods: A single-center quality improvement study with retrospective evaluation of the impact of antimicrobial stewardship measures on optimizing antibacterial use in intra-abdominal infections requiring emergency surgery was performed. The study was conducted in a tertiary hospital in Germany from January 1, 2016, to January 30, 2020, three years after putting a set of antimicrobial stewardship standards into effect. Results: 767 patients were analyzed (n = 495 in 2016 and 2017, the baseline period; n = 272 in 2018, the antimicrobial stewardship period). The total days of therapy per 100 patient days declined from 47.0 to 42.2 days (p = 0.035). The rate of patients receiving postoperative therapy decreased from 56.8\% to 45.2\% (p = 0.002), comparing both periods. There was a significant decline in the rate of inappropriate indications (17.4\% to 8.1 \%, p = 0.015) as well as a significant change from broad-spectrum to narrow-spectrum antibiotic use (28.8\% to 6.5\%, p ≤ 0.001) for postoperative therapy. The significant decline in antibiotic use did not affect either clinical outcomes or the rate of postoperative wound complications. Conclusions: Postoperative antibiotic use for intra-abdominal infections could be significantly reduced by antimicrobial stewardship interventions. The identification of inappropriate indications remains a key target for antimicrobial stewardship programs.}, language = {en} } @phdthesis{Drayss2022, author = {Drayß, Maria}, title = {Asymptomatisches Tr{\"a}gertum von Staphylococcus aureus und Haemophilus influenzae bei Senioren}, doi = {10.25972/OPUS-27227}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-272276}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {{\"A}ltere Menschen sind gegen{\"u}ber invasiven Infektionen und Sepsis besonders vulnerabel mit ung{\"u}nstiger Prognose. Staphylococcus aureus und Haemophilus influenzae k{\"o}nnen beide invasive Infektionen verursachen. Oft geht eine asymptomatische Besiedelung einer Infektion voraus und ist ein Risikofaktor f{\"u}r eine invasive Infektion. Daher wurde eine bizentrische Querschnittstudie in den Regionen Aachen und W{\"u}rzburg durchgef{\"u}hrt, um die Pr{\"a}valenz von H. influenzae, S. aureus und MRSA (Methicillin resistenter S. aureus) bei asymptomatischen Senioren zu bestimmen, wie auch Risikofaktoren f{\"u}r eine Besiedelung. Von Oktober 2012 bis Mai 2013 wurden 677 Erwachsenen im Alter von 65 Jahren oder {\"a}lter eingeschlossen, die zu Hause oder in Seniorenheimen lebten. Die Pr{\"a}valenz von H. influenzae bei {\"a}lteren Menschen war mit einer Tr{\"a}gerrate von nur 1,9\% ([95\% CI: 1,0 - 3,3\%]; 13/677) sehr niedrig. Tr{\"a}gerisolate waren {\"u}berwiegend nicht typisierbare H. influenzae, zeigten eine hohe clonale Diversit{\"a}t und waren alle Ampicillin-sensibel. Die Pr{\"a}valenz von S. aureus war mit 28,5\% ([95\% CI: 25,1 - 32,1\%]; 193/677) hoch, wie f{\"u}r die deutsche Allgemeinbev{\"o}lkerung bekannt, w{\"a}hrend MRSA bei weniger als 1\% der Teilnehmer gefunden wurde (0,7\% [95\% CI: 0,2 - 1,7\%]; 5/677). Die Pr{\"a}valenz von H. influenzae, S. aureus und MRSA unterschied sich nicht signifikant zwischen selbst{\"a}ndig zu Hause lebenden Senioren und Pflegeheimbewohnern. {\"A}ltere, selbst{\"a}ndig lebende Menschen mit h{\"o}herem Bildungsniveau hatten signifikant h{\"o}here Kolonisierungsraten mit S. aureus (adjusted OR: 1,905 [95\% CI: 1,248 - 2,908]; p = 0,003). Bei Pflegeheimbewohnern war eine Kolonisierung signifikant mit Verheiratet sein assoziiert (adjusted OR: 3,367 [95\% CI: 1,502 - 7,546]; p = 0,003). Diese Ergebnisse unterstreichen die Bedeutung von sozio-demographischen Faktoren f{\"u}r eine Kolonisierung mit S. aureus und schließen eine L{\"u}cke bei epidemiologischen Daten zu H. influenzae.}, subject = {Staphylococcus aureus}, language = {de} } @article{RohdeHimmelHofingeretal.2022, author = {Rohde, J{\"o}rn and Himmel, Wolfgang and Hofinger, Clemens and L{\^a}m, Thi{\^e}n-Tr{\´i} and Schrader, Hanna and Wallstabe, Julia and Kurzai, Oliver and G{\´a}gyor, Ildik{\´o}}, title = {Diagnostic accuracy and feasibility of a rapid SARS-CoV-2 antigen test in general practice - a prospective multicenter validation and implementation study}, series = {BMC Primary Care}, volume = {23}, journal = {BMC Primary Care}, number = {1}, doi = {10.1186/s12875-022-01756-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299659}, year = {2022}, abstract = {Background PCR testing is considered the gold standard for SARS-CoV-2 diagnosis but its results are earliest available hours to days after testing. Rapid antigen tests represent a diagnostic tool enabling testing at the point of care. Rapid antigen tests have mostly been validated by the manufacturer or in controlled laboratory settings only. External validation at the point of care, particularly in general practice where the test is frequently used, is needed. Furthermore, it is unclear how well point of care tests are accepted by the practice staff. Methods In this prospective multicenter validation study in primary care, general practitioners included adult individuals presenting with symptoms suggesting COVID-19. Each patient was tested by the general practitioner, first with a nasopharyngeal swab for the point of care test (Roche SARS-CoV-2 Rapid Antigen Test) and then with a second swab for PCR testing. Using the RT-PCR result as a reference, we calculated specificity, sensitivity, positive predictive value and negative predictive value, with their 95\% confidence intervals. General practitioners and medical assistants completed a survey to assess feasibility and usefulness of the point of care tests. Results In 40 practices in W{\"u}rzburg, Germany, 1518 patients were recruited between 12/2020 and 06/2021. The point of care test achieved a sensitivity of 78.3\% and a specificity of 99.5\% compared to RT-PCR. With a prevalence of 9.5\%, the positive predictive value was 93.9\% and the negative predictive value was 97.8\%. General practitioners rated the point of care test as a helpful tool to support diagnostics in patients with signs and symptoms suggestive for infection, particularly in situations where decision on further care is needed at short notice. Conclusion The point of care test used in this study showed a sensitivity below the manufacturer's specification (Sensitivity 96.25\%) in the practice but high values for specificity and high positive predictive value and negative predictive value. Although widely accepted in the practice, measures for further patient management require a sensitive interpretation of the point of care test results.}, language = {en} } @phdthesis{Stieber2022, author = {Stieber, Hanna}, title = {Auswirkungen des Sphingolipidsynthese-Inhibitors Myriocin auf Vitalit{\"a}t und Antimykotikaresistenz von \(Candida\) \(auris\)}, doi = {10.25972/OPUS-28912}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-289121}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Candida Spezies geh{\"o}ren als kommensale Organismen zur normalen menschlichen Mikroflora, k{\"o}nnen allerdings unter bestimmten Bedingungen Krankheitswert erlangen. Limitationen in der Behandlung durch immer mehr resistente Candida Spezies und die wachsende Zahl immunsupprimierter Patienten gelten als Hauptursachen f{\"u}r die steigende H{\"a}ufigkeit invasiver Candidosen und systemischer Candid{\"a}mien. Die 2009 entdeckte Spezies C. auris stellt durch ihre zahlreichen Resistenzen, das Potential zur Ausl{\"o}sung nosokomialer Ausbr{\"u}che in Krankenh{\"a}usern und die schnelle Verbreitung {\"u}ber mehrere Kontinente eine neue Herausforderung dar. Der Bedarf an neuen Antimykotika mit anderen Wirkmechanismen und neuen Zielstrukturen ist gr{\"o}ßer denn je. Die fungale Sphingolipid-Biosynthese wurde bereits mehrfach als potenzielles Ziel antimykotischer Therapie diskutiert, allerdings bezieht sich die meiste Forschung hierzu auf C. albicans]. In vorliegender Arbeit wurden die Auswirkungen der Inhibition der Sphingolipid Biosynthese durch Myriocin auf C. auris und sein Resistenzverhalten untersucht und mit denen auf andere Candida Spezies verglichen. Sowohl die Mikrodilution als auch die Plattentropftests zeigten, dass C. auris verglichen mit anderen Candida Spezies besonders sensitiv auf die Anwesenheit von Myriocin reagierte und st{\"a}rker im Wachstum gehemmt wurde. Der Survival Assay ergab f{\"u}r alle drei Spezies ein Absenken der CFU durch Myriocin, die Abweichungen zwischen den St{\"a}mmen waren jedoch unwesentlich. Unterschiede konnten in Vitalit{\"a}t und Vermehrung der verschiedenen Spezies unter Myriocineinfluss festgestellt werden. Aus der Lebend/Tot-F{\"a}rbung ging hervor, dass Myriocin bei allen St{\"a}mmen zum Absterben von Candida Zellen f{\"u}hrte, C. albicans und C. glabrata allerdings signifikant niedrigere {\"U}berlebensraten im Vergleich zu den C. auris Isolaten aufwiesen. Im Gegensatz dazu konnte mithilfe der FITC-Mikroskopie gezeigt werden, dass Candida Zellen unter Zugabe von Myriocin weniger Tochterzellen ausbildeten, was auf eine erschwerte oder zumindest verlangsamte Zellvermehrung hindeutet. Dabei schien das Wachstum der C. auris St{\"a}mme durch Myriocin deutlich eingeschr{\"a}nkter zu sein als das von C. albicans und C. glabrata. Durch weitere Mikroskopie und die Kombination aus Lebend/Tot F{\"a}rbung mittels PI und FITC F{\"a}rbung, sollte die Verteilung der toten Zellen auf Mutter- und Tochterzellen evaluiert werden. Hier konnte ein Trend zu einem vermehrten Zellsterben der Tochterzellen, vor allem f{\"u}r C. auris, festgestellt werden. Abschließende E-Tests f{\"u}r Amphotericin B, Anidulafungin und Fluconazol ergaben eine signifikante Herabsetzung der MHK f{\"u}r alle C. auris Isolate durch Myriocin. Die hier vorgestellten Ergebnisse und die durch mehrere Studien festgestellten Differenzen in der Sphingolipidkomposition von C. auris verglichen mit anderen Candida Spezies geben Hinweis darauf, dass Sphingolipide f{\"u}r Vitalit{\"a}t, Zellteilung und vor allem f{\"u}r die Wirkung einiger Antimykotika auf C. auris eine besondere, wenn nicht {\"u}bergestellte Bedeutung haben k{\"o}nnten. Zwar wurde die Sphingolipidsynthese bereits mehrfach als potenzieller Angriffspunkt f{\"u}r die antifungale Therapie diskutiert, allerdings lediglich am Beispiel anderer Candida Spezies. Der Sphingolipidstoffwechsel k{\"o}nnte somit ein vielversprechender Ansatz f{\"u}r die Behandlung des sonst so therapieresistenten und lebensbedrohlichen Pilzes C. auris sein.}, subject = {Candida}, language = {de} } @article{SchlegelPetersDooseetal.2019, author = {Schlegel, Jan and Peters, Simon and Doose, S{\"o}ren and Schubert-Unkmeir, Alexandra and Sauer, Markus}, title = {Super-resolution microscopy reveals local accumulation of plasma membrane gangliosides at Neisseria meningitidis Invasion Sites}, series = {Frontiers in Cell and Developmental Biology}, volume = {7}, journal = {Frontiers in Cell and Developmental Biology}, number = {194}, doi = {10.3389/fcell.2019.00194}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201639}, year = {2019}, abstract = {Neisseria meningitidis (meningococcus) is a Gram-negative bacterium responsible for epidemic meningitis and sepsis worldwide. A critical step in the development of meningitis is the interaction of bacteria with cells forming the blood-cerebrospinal fluid barrier, which requires tight adhesion of the pathogen to highly specialized brain endothelial cells. Two endothelial receptors, CD147 and the β2-adrenergic receptor, have been found to be sequentially recruited by meningococci involving the interaction with type IV pilus. Despite the identification of cellular key players in bacterial adhesion the detailed mechanism of invasion is still poorly understood. Here, we investigated cellular dynamics and mobility of the type IV pilus receptor CD147 upon treatment with pili enriched fractions and specific antibodies directed against two extracellular Ig-like domains in living human brain microvascular endothelial cells. Modulation of CD147 mobility after ligand binding revealed by single-molecule tracking experiments demonstrates receptor activation and indicates plasma membrane rearrangements. Exploiting the binding of Shiga (STxB) and Cholera toxin B (CTxB) subunits to the two native plasma membrane sphingolipids globotriaosylceramide (Gb3) and raft-associated monosialotetrahexosylganglioside GM1, respectively, we investigated their involvement in bacterial invasion by super-resolution microscopy. Structured illumination microscopy (SIM) and direct stochastic optical reconstruction microscopy (dSTORM) unraveled accumulation and coating of meningococci with GM1 upon cellular uptake. Blocking of CTxB binding sites did not impair bacterial adhesion but dramatically reduced bacterial invasion efficiency. In addition, cell cycle arrest in G1 phase induced by serum starvation led to an overall increase of GM1 molecules in the plasma membrane and consequently also in bacterial invasion efficiency. Our results will help to understand downstream signaling events after initial type IV pilus-host cell interactions and thus have general impact on the development of new therapeutics targeting key molecules involved in infection.}, language = {en} } @article{MarincolaLiongSchoenetal.2021, author = {Marincola, Gabriella and Liong, Olivia and Schoen, Christoph and Abouelfetouh, Alaa and Hamdy, Aisha and Wencker, Freya D. R. and Marciniak, Tessa and Becker, Karsten and K{\"o}ck, Robin and Ziebuhr, Wilma}, title = {Antimicrobial Resistance Profiles of Coagulase-Negative Staphylococci in Community-Based Healthy Individuals in Germany}, series = {Frontiers in Public Health}, volume = {9}, journal = {Frontiers in Public Health}, issn = {2296-2565}, doi = {10.3389/fpubh.2021.684456}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-240881}, year = {2021}, abstract = {Coagulase-negative staphylococci (CoNS) are common opportunistic pathogens, but also ubiquitous human and animal commensals. Infection-associated CoNS from healthcare environments are typically characterized by pronounced antimicrobial resistance (AMR) including both methicillin- and multidrug-resistant isolates. Less is known about AMR patterns of CoNS colonizing the general population. Here we report on AMR in commensal CoNS recovered from 117 non-hospitalized volunteers in a region of Germany with a high livestock density. Among the 69 individuals colonized with CoNS, 29 had reported contacts to either companion or farm animals. CoNS were selectively cultivated from nasal swabs, followed by species definition by 16S rDNA sequencing and routine antibiotic susceptibility testing. Isolates displaying phenotypic AMR were further tested by PCR for presence of selected AMR genes. A total of 127 CoNS were isolated and Staphylococcus epidermidis (75\%) was the most common CoNS species identified. Nine isolates (7\%) were methicillin-resistant (MR) and carried the mecA gene, with seven individuals (10\%) being colonized with at least one MR-CoNS isolate. While resistance against gentamicin, phenicols and spectinomycin was rare, high resistance rates were found against tetracycline (39\%), erythromycin (33\%) and fusidic acid (24\%). In the majority of isolates, phenotypic resistance could be associated with corresponding AMR gene detection. Multidrug-resistance (MDR) was observed in 23\% (29/127) of the isolates, with 33\% (23/69) of the individuals being colonized with MDR-CoNS. The combined data suggest that MR- and MDR-CoNS are present in the community, with previous animal contact not significantly influencing the risk of becoming colonized with such isolates.}, language = {en} } @article{WaltherZimmermannTheuersbacheretal.2021, author = {Walther, Grit and Zimmermann, Anna and Theuersbacher, Johanna and Kaerger, Kerstin and Lilienfeld-Toal, Marie von and Roth, Mathias and Kampik, Daniel and Geerling, Gerd and Kurzai, Oliver}, title = {Eye infections caused by filamentous fungi: spectrum and antifungal susceptibility of the prevailing agents in Germany}, series = {Journal of Fungi}, volume = {7}, journal = {Journal of Fungi}, number = {7}, issn = {2309-608X}, doi = {10.3390/jof7070511}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-241810}, year = {2021}, abstract = {Fungal eye infections can lead to loss of vision and blindness. The disease is most prevalent in the tropics, although case numbers in moderate climates are increasing as well. This study aimed to determine the dominating filamentous fungi causing eye infections in Germany and their antifungal susceptibility profiles in order to improve treatment, including cases with unidentified pathogenic fungi. As such, we studied all filamentous fungi isolated from the eye or associated materials that were sent to the NRZMyk between 2014 and 2020. All strains were molecularly identified and antifungal susceptibility testing according to the EUCAST protocol was performed for common species. In total, 242 strains of 66 species were received. Fusarium was the dominating genus, followed by Aspergillus, Purpureocillium, Alternaria, and Scedosporium. The most prevalent species in eye samples were Fusarium petroliphilum, F. keratoplasticum, and F. solani of the Fusarium solani species complex. The spectrum of species comprises less susceptible taxa for amphotericin B, natamycin, and azoles, including voriconazole. Natamycin is effective for most species but not for Aspergillus flavus or Purpureocillium spp. Some strains of F. solani show MICs higher than 16 mg/L. Our data underline the importance of species identification for correct treatment.}, language = {en} } @article{KurotschkaTiedemannWolfetal.2021, author = {Kurotschka, Peter Konstantin and Tiedemann, Elena and Wolf, Dominik and Thier, Nicola and Forster, Johannes and Liese, Johannes G. and Gagyor, Ildiko}, title = {Management of common infections in German primary care: a cross-sectional survey of knowledge and confidence among General Practitioners and outpatient pediatricians}, series = {Antibiotics}, volume = {10}, journal = {Antibiotics}, number = {9}, issn = {2079-6382}, doi = {10.3390/antibiotics10091131}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-246272}, year = {2021}, abstract = {Outpatient antibiotic use is closely related to antimicrobial resistance and in Germany, almost 70\% of antibiotic prescriptions in human health are issued by primary care physicians (PCPs). The aim of this study was to explore PCPs, namely General Practitioners' (GPs) and outpatient pediatricians' (PDs) knowledge of guideline recommendations on rational antimicrobial treatment, the determinants of confidence in treatment decisions and the perceived need for training in this topic in a large sample of PCPs from southern Germany. Out of 3753 reachable PCPs, 1311 completed the survey (overall response rate = 34.9\%). Knowledge of guideline recommendations and perceived confidence in making treatment decisions were high in both GPs and PDs. The two highest rated influencing factors on prescribing decisions were reported to be guideline recommendations and own clinical experiences, hence patients' demands and expectations were judged as not influencing treatment decisions. The majority of physicians declared to have attended at least one specific training course on antibiotic use, yet almost all the participating PCPs declared to need more training on this topic. More studies are needed to explore how consultation-related and context-specific factors could influence antibiotic prescriptions in general and pediatric primary care in Germany beyond knowledge. Moreover, efforts should be undertaken to explore the training needs of PCPs in Germany, as this would serve the development of evidence-based educational interventions targeted to the improvement of antibiotic prescribing decisions rather than being focused solely on knowledge of guidelines.}, language = {en} } @phdthesis{Nuernberg2023, author = {N{\"u}rnberg, Sebastian}, title = {Invasive \(Haemophilus\) \(influenzae\)-Isolate in Deutschland: Methodenvalidierung des VITEK MS IVD MALDI-TOF-MS und Untersuchung von Resistenzen gegen Imipenem und Cefotaxim}, doi = {10.25972/OPUS-34506}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-345067}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Die Inzidenz invasiver H. influenzae-Infektionen in Deutschland steigt seit Jahren an. Die akkurate Identifizierung und Resistenztestung dieses Erregers sind von großer klinischer und epidemiologischer Bedeutung. Daher wurden im Rahmen der vorliegenden Promotionsarbeit umfangreiche Untersuchungen zur Diagnostik und zur Epidemiologie von Antibiotikaresistenzen bei H. influenzae durchgef{\"u}hrt. Es konnte gezeigt werden, dass die in der Routinediagnostik mittlerweile weit verbreitete MALDI-TOF-MS-Diagnostik durch das VITEK MS IVD nur eingeschr{\"a}nkt zur sicheren Unterscheidung von H. influenzae und H. haemolyticus einsetzbar ist. H. influenzae-Isolate erkannte das System mit einer Genauigkeit von 100 \%. Bei H. haemolyticus-Isolaten wurden dagegen 42 \% der untersuchten St{\"a}mme f{\"a}lschlicherweise als H. influenzae erkannt. Dieser Fragestellung wurde mit der bisher umfangreichsten molekularbiologisch charakterisierten Studienpopulation beider Bakterienspezies nachgegangen. Die kalkulierte antibiotische Therapie einer Sepsis oder Meningitis erfolgt h{\"a}ufig mit Carbapenemen, die leitliniengerechte Therapie invasiver H. influenzae-Infektionen mit Drittgenerations-Cephalosporinen. Imipenem und Cefotaxim geh{\"o}ren zu den Hauptvertretern dieser Gruppen. Bez{\"u}glich der Antibiotikaresistenztestung wurde erstmalig f{\"u}r H. influenzae herausgefunden, dass die routinem{\"a}ßig verwendete Gradientenagardiffusion (GAD) bei der Testung von Cefotaxim im Vergleich zum Goldstandard Bouillon-Mikrodilution gleichwertig und bei Imipenem sogar sensitiver in der Detektion von Heteroresistenzen ist. Die Epidemiologie dieser Resistenzen wurde in dieser Arbeit erstmalig f{\"u}r Deutschland systematisch erfasst, indem alle verf{\"u}gbaren invasiven Isolate gemeldeter H. influenzae-Infektionen der Jahre 2016 (Imipenem) beziehungsweise 2016-2019 (Cefotaxim) untersucht wurden. Es wurde eine hohe Pr{\"a}valenz einer Imipenem-Resistenz von 13,5 \% festgestellt. Die Pr{\"a}valenz einer Cefotaxim-Resistenz lag bei 0,9 \%. Zur molekularen Typisierung wurde bei den Imipenem-resistenten Isolaten eine Multilocus-Sequenztypisierung, bei den Cefotaxim-resistenten St{\"a}mmen eine Sequenzierung des vollst{\"a}ndigen Genoms durchgef{\"u}hrt. Hierbei wurde eine hohe genetische Diversit{\"a}t der St{\"a}mme festgestellt, was die Schlussfolgerung zul{\"a}sst, dass resistente Mutanten sporadisch entstehen. Die Untersuchung m{\"o}glicher spatio-temporaler Cluster f{\"u}hrte zum Nachweis einer sehr selten vorkommenden {\"U}bertragung eines Imipenem-resistenten Stamms. Durch die Sequenzierung von Resistenzgenen wurde die Epidemiologie und Relevanz bekannter Aminos{\"a}uresubstitutionen beleuchtet. Unter anderem wurde f{\"u}r die PBP3-Substitutionen L389F und Y557H eine hochsignifikante Korrelation mit dem Auftreten von Cefotaxim-Resistenzen nachgewiesen. Die gewonnenen Genomdaten bieten die Grundlage f{\"u}r die Forschung an weiteren Antibiotikaresistenzdeterminanten von H. influenzae.}, subject = {Haemophilus influenzae}, language = {de} } @phdthesis{Koike2023, author = {Koike, Akito}, title = {Molekular und zellbiologischer Ansatz hin zu neuartigen Medikamenten gegen \(Echinococcus\) \(multilocularis\)}, doi = {10.25972/OPUS-28864}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288649}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Echinococcosis is an important zoonosis. The causative agent of Alveolar Echinococcosis (AE) is Echinococcus multilocularis. The treatment of human AE is limited to surgery and chemotherapy with albendazole (ABZ). However, ABZ works only parasitostatically and it needs to be taken for long periods, although it causes adverse side effects. Thus, development of new, parasiticidal drug with selective toxicity is required. Because undifferentiated stem cells of E. multilocularis play key role in its longevity and regenerative capacity, targeting stem cells is especially important. In vitro screening of protein kinases inhibitors demonstrated that human PIM kinases inhibitors have detrimental effects on E. multilocularis. Through yeast two hybrid assay, the interaction of parasite PIM kinase (EmPIM) and its CDC25 (EmCDC25) was indicated. Through in situ hybridization, expression of EmPIM in the stem cells was observed. Therefore, EmPim is likely to be a positive regulator of cell cycle progression, the same as human Pim1. In addition, 20 compounds against EmPIM were selected through in silico screening and synthesized. One of them has a detrimental effect on E.multilocularis comparable to human pan-PIM inhibitors, but has much weaker toxicity on human cell lines. Furthermore, triclabendazole (TCBZ) and its metabolite TCBZSX, which are approved for another flatworm disease, Fascioliasis were tried on E. multilocularis. With two stem cell markers, damage to stem cells by TCBZSX was shown. In addition, primary cells from treated vesicles never regenerated and the damage to stem cells proved to be irreversible. Our in silico screening method used in EmPIM research has potential to identify compounds which overcome the side effect problem in ABZ-based chemotherapy. On the other hand, it is expected that my research of TCBZ can lead to development of a practical parasiticidal chemotherapy by combining TCBZ, which damages stem cells, and ABZ, which damages differentiated cells.}, subject = {Bandw{\"u}rmer}, language = {en} } @article{StraubVollmerLametal.2022, author = {Straub, Anton and Vollmer, Andreas and L{\^a}m, Thi{\^e}n-Tr{\´i} and Brands, Roman C. and Stapf, Maximilian and Scherf-Clavel, Oliver and Bittrich, Max and Fuchs, Andreas and K{\"u}bler, Alexander C. and Hartmann, Stefan}, title = {Evaluation of advanced platelet-rich fibrin (PRF) as a bio-carrier for ampicillin/sulbactam}, series = {Clinical Oral Investigations}, volume = {26}, journal = {Clinical Oral Investigations}, number = {12}, doi = {10.1007/s00784-022-04663-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-324515}, pages = {7033-7044}, year = {2022}, abstract = {Objectives Mechanisms of wound healing are often impaired in patients with osteonecrosis of the jaw (ONJ). According to the guidelines for the treatment of this disease, early surgical intervention is indicated. However, surgery often faces complications such as wound healing disorders. The application of platelet-rich fibrin (PRF) after necrosectomy between bone and mucosa may constitute a promising approach to improve surgical results. An aspect that was not investigated until now is that PRF acts as a "bio-carrier" for antibiotics previously applied intravenously. Materials and methods We investigated the antimicrobial properties of PRF in 24 patients presenting ONJ undergoing systemic antibiosis with ampicillin/sulbactam. We measured the concentration of ampicillin/sulbactam in plasma and PRF and performed agar diffusion tests. Ampicillin/sulbactam was applied intravenously to the patient 10 minutes for blood sampling for PRF. No further incorporation of patients' blood or PRF product with antibiotic drugs was obtained. Four healthy patients served as controls. Results Our results revealed that PRF is highly enriched with ampicillin/sulbactam that is released to the environment. The antibiotic concentration in PRF was comparable to the plasma concentration of ampicillin/sulbactam. The inhibition zone (IZ) of PRF was comparable to the standard ampicillin/sulbactam discs used in sensitivity testing. Conclusions The results of our study demonstrated that PRF is a reliable bio-carrier for systemic applied antibiotics and exhibits a large antimicrobial effect. Clinical relevance We describe a clinically useful feature of PRF as a bio-carrier for antibiotics. Especially when applied to poorly perfused tissues and bone such as in ONJ, the local release of antibiotics can reduce wound healing disorders like infections.}, language = {en} } @phdthesis{Wilhelm2024, author = {Wilhelm, Hannah}, title = {Multiresistenzen in klinischen \(C.glabrata\) Isolaten}, doi = {10.25972/OPUS-34718}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347186}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Die Zahl invasiver Pilzinfektionen ausgel{\"o}st durch C. glabrata steigt zunehmend und auch die Ausbildung multipler Resistenzen wird immer h{\"a}ufiger registriert. In dieser Arbeit wurden zwei klinische MDR-C. glabrata-St{\"a}mme systematisch analysiert, um den Ursprung der Mehrfachresistenz zu finden. Aufgefallen waren jene Isolate in vorhergehenden Untersuchungen von Aldejohann et. al., die 176 St{\"a}mme, die dem Referenzzentrum NRZ-Myk zugesandt wurden, auf ihr Resistenzverhalten gegen Echinocandine analysierten und auf FKS-Mutationen untersuchten. Die Isolate CG22 und CG56 zeigten ein Resistenzverhalten gegen Anidulafungin ohne eine FKS-Mutation aufzuweisen. In Mehrfachtestungen wurde das einheitliche Verhalten von CG56 in zehn Einzelkolonien verifiziert, um Mischkulturen oder heterogenes Verhalten innerhalb des Isolates ausschließen zu k{\"o}nnen. Nach Analyse der gesamten Genomsequenz von CG56 zeigte sich eine Mutation kurz vor der HS-Region von FKS2, die eine Erkl{\"a}rung f{\"u}r das Resistenzverhalten zu liefern scheint. Neben der Mutation in FKS2 wurde ebenfalls eine Mutation in FKS1 und in ERG3 best{\"a}tigt. Die Mutation in ERG3 f{\"u}hrt zu einer Verschiebung im Sterolsynthesepathway und zu einer Neuverteilung der Zellmembranbestandteile. Das klinische Isolat CG22 f{\"a}llt mit Resistenzen gegen Azole, Echinocandine und Amphotericin B auf und zeigte ebenfalls eine Mutationen in ERG3. Zus{\"a}tzlich dazu ergab sich eine Loss-of- Function-Mutation in ERG4 und damit verbunden einen massiv reduzierten Ergosterolgehalt der Zellmembran. Die seltene Kombination aus ERG3 und ERG4 Mutation scheint die Erkl{\"a}rung f{\"u}r die außergew{\"o}hnliche Amphotericin B-Resistenz von CG22 zu liefern und wird hier als erstmals bei einem C. glabrata Isolat beschrieben. Dieser besondere Stamm, der sogar als panresistent bezeichnet werden kann, sollte Bestandteil weiterer Forschung werden. Der Sterolsynthesepathway dient als Angriffspunkt vieler Antimykotika und kann durch seine vielen Intermediate und abweichenden Abl{\"a}ufen zu unterschiedlichen Stoffwechselendprodukten f{\"u}hren. Der Ergosterolgehalt der Zellmembran eines C. glabrata-Stammes kann weitere R{\"u}ckschl{\"u}sse auf die Empfindlichkeit des Isolates geben und somit die Chancen des Therapieerfolges der Antimykotikagabe besser vorhersagen und k{\"o}nnte somit einen vielversprechenden Beitrag zur Behandlung lebensbedrohlicher Candidosen leisten.}, subject = {Torulopsis glabrata}, language = {de} } @article{AbimannanSumathiKrishnarajasekharetal.2019, author = {Abimannan, Nagarajan and Sumathi, G. and Krishnarajasekhar, O. R. and Sinha, Bhanu and Krishnan, Padma}, title = {Clonal Clusters and Virulence Factors of Methicillin-Resistant \(Staphylococcus\) \(Aureus\): Evidence for Community-Acquired Methicillin-Resistant \(Staphylococcus\) \(Aureus\) Infiltration into Hospital Settings in Chennai, South India}, series = {Indian Journal of Medical Microbiology}, volume = {37}, journal = {Indian Journal of Medical Microbiology}, number = {3}, doi = {10.4103/ijmm.IJMM_18_271}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226963}, pages = {326-336}, year = {2019}, abstract = {Background and Objective: Staphylococcus aureus is one of the major pathogens of nosocomial infections as wells as community-acquired (CA) infections worldwide. So far, large-scale comprehensive molecular and epidemiological characterisation of S. aureus from very diverse settings has not been carried out in India. The objective of this study is to evaluate the molecular, epidemiological and virulence characteristics of S. aureus in both community and hospital settings in Chennai, southern India. Methods: S. aureus isolates were obtained from four different groups (a) healthy individuals from closed community settings, (b) inpatients from hospitals, (c) outpatients from hospitals, representing isolates of hospital-community interface and (d) HIV-infected patients to define isolates associated with the immunocompromised. Antibiotic susceptibility testing, multiplex polymerase chain reactions for detection of virulence and resistance determinants, molecular typing including Staphylococcal cassette chromosome mec (SCCmec) and agr typing, were carried out. Sequencing-based typing was done using spa and multilocus sequence typing (MLST) methods. Clonal complexes (CC) of hospital and CA methicillin-resistant S. aureus (MRSA) were identified and compared for virulence and resistance. Results and Conclusion: A total of 769 isolates of S. aureus isolates were studied. The prevalence of MRSA was found to be 7.17\%, 81.67\%, 58.33\% and 22.85\% for groups a, b, c and d, respectively. Of the four SCCmec types (I, III, IV and V) detected, SCCmec V was found to be predominant. Panton-Valentine leucocidin toxin genes were detected among MRSA isolates harbouring SCCmec IV and V. A total of 78 spa types were detected, t657 being the most prevalent. 13 MLST types belonging to 9 CC were detected. CC1 (ST-772, ST-1) and CC8 (ST238, ST368 and ST1208) were found to be predominant among MRSA. CA-MRSA isolates with SCCmec IV and V were isolated from all study groups including hospitalised patients and were found to be similar by molecular tools. This shows that CA MRSA has probably infiltrated into the hospital settings.}, language = {en} } @phdthesis{Koch2024, author = {Koch, Thorsten Manfred}, title = {Wirt - Pathogen Interaktion bei Hornhautinfektionen durch \(Fusarium\) spp.}, doi = {10.25972/OPUS-34777}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-347774}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Fusarium (F.)-Infektionen des Auges zeigen oft einen schwerwiegenden Verlauf und sind am h{\"a}ufigsten mit Spezies des Fusarium solani species complex assoziiert. Dabei sind das Tragen von weichen Kontaktlinsen sowie Traumata die wichtigsten pr{\"a}disponierenden Faktoren. Vorangegangene Untersuchungen des Nationalen Referenzzentrums f{\"u}r invasive Pilzinfektionen hatten ergeben, dass Infektionen durch F. petroliphilum mit der Nutzung von Kontaktlinsen, Infektionen durch F. falciforme jedoch {\"u}berwiegend traumaassoziiert uns vor allem aus tropischen und subtropischen L{\"a}ndern bekannt sind. Das Ziel dieser Arbeit war es daher zu untersuchen, ob F. falcifomre und F. petroliphilum physiologische Merkmale aufweisen, die f{\"u}r die Unterschiede in den Risikofaktoren f{\"u}r Keratitiden durch die beiden Arten verantwortlich sein k{\"o}nnten.}, subject = {Fusarium}, language = {de} } @article{MoremiClausVogeletal.2019, author = {Moremi, Nyambura and Claus, Heike and Vogel, Ulrich and Mshana, Stephen E.}, title = {The role of patients and healthcare workers Staphylococcus aureus nasal colonization in occurrence of surgical site infection among patients admitted in two centers in Tanzania}, series = {Antimicrobial Resistance \& Infection Control}, volume = {8}, journal = {Antimicrobial Resistance \& Infection Control}, doi = {10.1186/s13756-019-0554-y}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-224185}, year = {2019}, abstract = {Background Colonization with Staphylococcus aureus has been identified as a risk for subsequent occurrence of infection. This study investigated the relationship between S. aureus colonization of patients and healthcare workers (HCWs), and subsequent surgical site infections (SSI). Methods Between December 2014 and September 2015, a total of 930 patients and 143 HCWs were enrolled from the Bugando Medical Centre and Sekou Toure hospital in Mwanza, Tanzania. On admission and discharge nasal swabs, with an additional of wound swab for those who developed SSI were collected from patients whereas HCWs were swabbed once. Identification and antimicrobial susceptibility testing were done by VITEK-MS and VITEK-2, respectively. Detection of Panton Valentine leukocidin (PVL) and mecA genes was done by PCR. S. aureus isolates were further characterized by spa typing and Multi-Locus Sequence Typing (MLST). Results Among 930 patients screened for S. aureus on admission, 129 (13.9\%) were positive of which 5.4\% (7/129) were methicillin-resistant S. aureus (MRSA). Amongst 363 patients rescreened on discharge, 301 patients had been tested negative on admission of whom 29 (9.6\%) turned positive after their hospital stay. Three (10.3\%) of the 29 acquired S. aureus were MRSA. Inducible Clindamycin resistance occurred more often among acquired S. aureus isolates than among isolates from admission [34.5\% (10/29) vs. 17.1\% (22/129), P = 0.018]. S. aureus contributed to 21.1\% (n = 12) of the 57 cases of investigated SSIs among 536 patients followed. Seven out of eight S. aureus carriage/infection pairs had the same spa and sequence types. The previously reported dominant PVL-positive ST88 MRSA strain with spa type t690 was detected in patients and HCW. Conclusion A significant proportion of patients acquired S. aureus during hospitalization. The finding of more than 90\% of S. aureus SSI to be of endogenous source underscores the need of improving infection prevention and control measures including screening and decolonization of high risk patients.}, language = {en} } @article{RufBrantlWagener2018, author = {Ruf, Dominik and Brantl, Victor and Wagener, Johannes}, title = {Mitochondrial Fragmentation in \(Aspergillus\) \(fumigatus\) as Early Marker of Granulocyte Killing Activity}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {8}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {128}, doi = {10.3389/fcimb.2018.00128}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-227133}, year = {2018}, abstract = {The host's defense against invasive mold infections relies on diverse antimicrobial activities of innate immune cells. However, studying these mechanisms in vitro is complicated by the filamentous nature of such pathogens that typically form long, branched, multinucleated and compartmentalized hyphae. Here we describe a novel method that allows for the visualization and quantification of the antifungal killing activity exerted by human granulocytes against hyphae of the opportunistic pathogen Aspergillus fumigatus. The approach relies on the distinct impact of fungal cell death on the morphology of mitochondria that were visualized with green fluorescent protein (GFP). We show that oxidative stress induces complete fragmentation of the tubular mitochondrial network which correlates with cell death of affected hyphae. Live cell microscopy revealed a similar and non-reversible disruption of the mitochondrial morphology followed by fading of fluorescence in Aspergillus hyphae that were killed by human granulocytes. Quantitative microscopic analysis of fixed samples was subsequently used to estimate the antifungal activity. By utilizing this assay, we demonstrate that lipopolysaccharides as well as human serum significantly increase the killing efficacy of the granulocytes. Our results demonstrate that evaluation of the mitochondrial morphology can be utilized to assess the fungicidal activity of granulocytes against A. fumigatus hyphae.}, language = {en} } @article{DrayssClausHubertetal.2019, author = {Drayß, Maria and Claus, Heike and Hubert, Kerstin and Thiel, Katrin and Berger, Anja and Sing, Andreas and van der Linden, Mark and Vogel, Ulrich and L{\^a}m, Thi{\^e}n-Tr{\´i}}, title = {Asymptomatic carriage of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, Group A Streptococcus and Staphylococcus aureus among adults aged 65 years and older}, series = {PLoS ONE}, volume = {14}, journal = {PLoS ONE}, number = {2}, doi = {10.1371/journal.pone.0212052}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201042}, pages = {e0212052}, year = {2019}, abstract = {Objective The aim of this study was to determine the prevalence of Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae, group A Streptococcus (GAS), and Staphylococcus aureus in asymptomatic elderly people and to unravel risk factors leading to colonization. Methods A multi-centre cross-sectional study was conducted including 677 asymptomatic adults aged 65 years or more, living at home or in nursing homes. Study areas were Greater Aachen (North-Rhine-Westphalia) and Wuerzburg (Bavaria), both regions with medium to high population density. Nasal and oropharyngeal swabs as well as questionnaires were collected from October 2012 to May 2013. Statistical analysis included multiple logistic regression models. Results The carriage rate was 1.9\% ([95\%CI: 1.0-3.3\%]; 13/677) for H. influenzae, 0.3\% ([95\%CI: 0-1.1\%]; 2/677) for N. meningitidis and 0\% ([95\% CI: 0-0.5\%]; 0/677) for S. pneumoniae and GAS. Staphylococcus aureus was harboured by 28.5\% of the individuals ([95\% CI: 25.1-32.1\%]; 193/677) and 0.7\% ([95\% CI: 0.2-1.7\%]; 5/677) were positive for methicillin-resistant S. aureus. Among elderly community-dwellers colonization with S. aureus was significantly associated with higher educational level (adjusted OR: 1.905 [95\% CI: 1.248-2.908]; p = 0.003). Among nursing home residents colonization was associated with being married (adjusted OR: 3.367 [1.502-7.546]; p = 0.003). Conclusion The prevalence of N. meningitidis, H. influenzae, S. pneumoniae and GAS was low among older people in Germany. The S. aureus rate was expectedly high, while MRSA was found in less than 1\% of the individuals.}, language = {en} } @article{LuberLutzAbeleHornetal.2019, author = {Luber, Verena and Lutz, Mathias and Abele-Horn, Marianne and Einsele, Hermann and Grigoleit, G{\"o}tz Ulrich and Mielke, Stephan}, title = {Excretion of Ascaris lumbricoides following reduced-intensity allogeneic hematopoietic stem cell transplantation and consecutive treatment with mebendazole}, series = {Transplant Infectious Disease}, volume = {22}, journal = {Transplant Infectious Disease}, number = {1}, issn = {1399-3062}, doi = {10.1111/tid.13224}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-219608}, pages = {1-4}, year = {2019}, abstract = {Here, we present the unique case of a 51-year-old German patient with multiple myeloma excreting Ascaris lumbricoides in his stool five weeks after allogeneic hematopoietic stem cell transplantation. Stool analysis remained negative for the presence of eggs, and there was no eosinophilia in the peripheral blood at any time around stem cell transplantation. The patient was commenced on a three-day treatment with mebendazole, which was well tolerated. No serious interactions with the concomitant post-transplant medication or negative effects on the hematopoiesis were observed, and the myeloma still is in complete remission. To our knowledge, this is the first report on excretion of A lumbricoides in the context of allogeneic stem cell transplantation. The case is remarkable with view to the fact that the parasite has supposedly survived all courses of myeloma treatment including autologous and allogeneic conditioning. Parasitosis with A lumbricoides has a worldwide prevalence of about a billion and is extremely rare in northern Europe. Possibly the patient got infected during a trip to Egypt years before multiple myeloma was diagnosed.}, language = {en} } @article{PrausseLehnertTimmeetal.2018, author = {Prauße, Maria T. E. and Lehnert, Teresa and Timme, Sandra and H{\"u}nniger, Kerstin and Leonhardt, Ines and Kurzai, Oliver and Figge, Marc Thilo}, title = {Predictive Virtual Infection Modeling of Fungal Immune Evasion in Human Whole Blood}, series = {Frontiers in Immunology}, volume = {9}, journal = {Frontiers in Immunology}, number = {560}, issn = {1664-3224}, doi = {10.3389/fimmu.2018.00560}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197493}, year = {2018}, abstract = {Bloodstream infections by the human-pathogenic fungi Candida albicans and Candida glabrata increasingly occur in hospitalized patients and are associated with high mortality rates. The early immune response against these fungi in human blood comprises a concerted action of humoral and cellular components of the innate immune system. Upon entering the blood, the majority of fungal cells will be eliminated by innate immune cells, i.e., neutrophils and monocytes. However, recent studies identified a population of fungal cells that can evade the immune response and thereby may disseminate and cause organ dissemination, which is frequently observed during candidemia. In this study, we investigate the so far unresolved mechanism of fungal immune evasion in human whole blood by testing hypotheses with the help of mathematical modeling. We use a previously established state-based virtual infection model for whole-blood infection with C. albicans to quantify the immune response and identified the fungal immune-evasion mechanism. While this process was assumed to be spontaneous in the previous model, we now hypothesize that the immune-evasion process is mediated by host factors and incorporate such a mechanism in the model. In particular, we propose, based on previous studies that the fungal immune-evasion mechanism could possibly arise through modification of the fungal surface by as of yet unknown proteins that are assumed to be secreted by activated neutrophils. To validate or reject any of the immune-evasion mechanisms, we compared the simulation of both immune-evasion models for different infection scenarios, i.e., infection of whole blood with either C. albicans or C. glabrata under non-neutropenic and neutropenic conditions. We found that under non-neutropenic conditions, both immune-evasion models fit the experimental data from whole-blood infection with C. albicans and C. glabrata. However, differences between the immune-evasion models could be observed for the infection outcome under neutropenic conditions with respect to the distribution of fungal cells across the immune cells. Based on these predictions, we suggested specific experimental studies that might allow for the validation or rejection of the proposed immune-evasion mechanism.}, language = {en} } @article{BecamWalterBurgertetal.2017, author = {Becam, J{\´e}r{\^o}me and Walter, Tim and Burgert, Anne and Schlegel, Jan and Sauer, Markus and Seibel, J{\"u}rgen and Schubert-Unkmeir, Alexandra}, title = {Antibacterial activity of ceramide and ceramide analogs against pathogenic Neisseria}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, doi = {10.1038/s41598-017-18071-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159367}, pages = {17627}, year = {2017}, abstract = {Certain fatty acids and sphingoid bases found at mucosal surfaces are known to have antibacterial activity and are thought to play a more direct role in innate immunity against bacterial infections. Herein, we analysed the antibacterial activity of sphingolipids, including the sphingoid base sphingosine as well as short-chain C\(_{6}\) and long-chain C\(_{16}\)-ceramides and azido-functionalized ceramide analogs against pathogenic Neisseriae. Determination of the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) demonstrated that short-chain ceramides and a ω-azido-functionalized C\(_{6}\)-ceramide were active against Neisseria meningitidis and N. gonorrhoeae, whereas they were inactive against Escherichia coli and Staphylococcus aureus. Kinetic assays showed that killing of N. meningitidis occurred within 2 h with ω-azido-C\(_{6}\)-ceramide at 1 X the MIC. Of note, at a bactericidal concentration, ω-azido-C\(_{6}\)-ceramide had no significant toxic effect on host cells. Moreover, lipid uptake and localization was studied by flow cytometry and confocal laser scanning microscopy (CLSM) and revealed a rapid uptake by bacteria within 5 min. CLSM and super-resolution fluorescence imaging by direct stochastic optical reconstruction microscopy demonstrated homogeneous distribution of ceramide analogs in the bacterial membrane. Taken together, these data demonstrate the potent bactericidal activity of sphingosine and synthetic short-chain ceramide analogs against pathogenic Neisseriae.}, language = {en} } @article{WagenerLoiko2017, author = {Wagener, Johannes and Loiko, Veronika}, title = {Recent insights into the paradoxical effect of echinocandins}, series = {Journal of Fungi}, volume = {4}, journal = {Journal of Fungi}, number = {1}, issn = {2309-608X}, doi = {10.3390/jof4010005}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-197960}, pages = {5}, year = {2017}, abstract = {Echinocandin antifungals represent one of the most important drug classes for the treatment of invasive fungal infections. The mode of action of the echinocandins relies on inhibition of the β-1,3-glucan synthase, an enzyme essentially required for the synthesis of the major fungal cell wall carbohydrate β-1,3-glucan. Depending on the species, echinocandins may exert fungicidal or fungistatic activity. Apparently independent of this differential activity, a surprising in vitro phenomenon called the "paradoxical effect" can be observed. The paradoxical effect is characterized by the ability of certain fungal isolates to reconstitute growth in the presence of higher echinocandin concentrations, while being fully susceptible at lower concentrations. The nature of the paradoxical effect is not fully understood and has been the focus of multiple studies in the last two decades. Here we concisely review the current literature and propose an updated model for the paradoxical effect, taking into account recent advances in the field.}, language = {en} } @article{SturmGeisselMartinetal.2020, author = {Sturm, Laura and Geißel, Bernadette and Martin, Ronny and Wagener, Johannes}, title = {Differentially Regulated Transcription Factors and ABC Transporters in a Mitochondrial Dynamics Mutant Can Alter Azole Susceptibility of Aspergillus fumigatus}, series = {Frontiers in Microbiology}, volume = {11}, journal = {Frontiers in Microbiology}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.01017}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-204874}, year = {2020}, abstract = {Azole resistance of the fungal pathogen Aspergillus fumigatus is an emerging problem. To identify novel mechanisms that could mediate azole resistance in A. fumigatus, we analyzed the transcriptome of a mitochondrial fission/fusion mutant that exhibits increased azole tolerance. Approximately 12\% of the annotated genes are differentially regulated in this strain. This comprises upregulation of Cyp51A, the azole target structure, upregulation of ATP-binding cassette (ABC) superfamily and major facilitator superfamily (MFS) transporters and differential regulation of transcription factors. To study their impact on azole tolerance, conditional mutants were constructed of seven ABC transporters and 17 transcription factors. Under repressed conditions, growth rates and azole susceptibility of the mutants were similar to wild type. Under induced conditions, several transcription factor mutants showed growth phenotypes. In addition, four ABC transporter mutants and seven transcription factor mutants exhibited altered azole susceptibility. However, deletion of individual identified ABC transporters and transcription factors did not affect the increased azole tolerance of the fission/fusion mutant. Our results revealed the ability of multiple ABC transporters and transcription factors to modulate the azole susceptibility of A. fumigatus and support a model where mitochondrial dysfunctions trigger a drug resistance network that mediates azole tolerance of this mold.}, language = {en} } @article{MoremiClausMshana2016, author = {Moremi, Nyambura and Claus, Heike and Mshana, Stephen E.}, title = {Antimicrobial resistance pattern: a report of microbiological cultures at a tertiary hospital in Tanzania}, series = {BMC Infectious Diseases}, volume = {16}, journal = {BMC Infectious Diseases}, number = {756}, doi = {10.1186/s12879-016-2082-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-161185}, year = {2016}, abstract = {Background Antimicrobial resistance has been declared by the World Health Organization as a threat to the public health. The aim of this study was to analyze antimicrobial resistance patterns of the common pathogens occurring at the Bugando Medical Centre (BMC), Mwanza, Tanzania to provide data for antimicrobial stewardship programmes. Methods A total of 3330 microbiological culture results scripts representing non-repetitive specimens reported between June 2013 and May 2015 were retrieved and analyzed for pathogens and their susceptibility patterns using STATA-11 software. Results Out of 3330 specimens, 439 (13.2\%) had positive culture. Staphylococcus aureus (n = 100; 22.8\%), Klebsiella pneumoniae (n = 65; 14.8\%) and Escherichia coli (n = 41; 9.3\%) were the most frequently isolated bacteria. Of 78 Staphylococcus aureus tested, 27 (34.6\%) were found to be methicillin resistant Staphylococcus aureus (MRSA). Rates of resistance of Klebsiella pneumoniae and Escherichia coli isolates to third generation cephalosporins were 38.5\% (25/65) and 29.3\% (12/41) respectively. Staphylococcus aureus and Klesbiella pneumoniae were commonly isolated from bloodstream infections while Escherichia coli and Pseudomonas aeruginosa were the predominant isolates from urinary tract and wounds infections respectively. Of 23 Salmonella species isolated, 22 (95\%) were recovered from the blood. Nine of the 23 Salmonella species isolates (39\%) were found to be resistant to third generation cephalosporins. The resistance rate of gram-negative bacteria to third generation cephalosporins increased from 26.5\% in 2014 to 57.9\% in 2015 (p = 0.004) while the rate of MRSA decreased from 41.2\% in 2013 to 9.5\% in 2015 (p = 0.016). Multidrug-resistant gram-negative isolates were commonly isolated from Intensive Care Units and it was noted that, the majority of invasive infections were due to gram-negative bacteria. Conclusion There is an increase in proportion of gram-negative isolates resistant to third generation cephalosporins. The diversity of potential pathogens resistant to commonly prescribed antibiotics underscores the importance of sustained and standardized antimicrobial resistance surveillance and antibiotic stewardship programmes in developing countries.}, language = {en} } @article{GlaserSilwedelFehrholzetal.2017, author = {Glaser, Kirsten and Silwedel, Christine and Fehrholz, Markus and Waaga-Gasser, Ana M. and Henrich, Birgit and Claus, Heike and Speer, Christian P.}, title = {Ureaplasma Species Differentially Modulate Pro- and Anti-Inflammatory Cytokine Responses in Newborn and Adult Human Monocytes Pushing the State Toward Pro-Inflammation}, series = {Frontiers in Cellular and Infection Microbiology}, volume = {7}, journal = {Frontiers in Cellular and Infection Microbiology}, number = {484}, doi = {10.3389/fcimb.2017.00484}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-169958}, year = {2017}, abstract = {Background: Ureaplasma species have been associated with chorioamnionitis and preterm birth and have been implicated in the pathogenesis of neonatal short and long-term morbidity. However, being mostly commensal bacteria, controversy remains on the pro-inflammatory capacity of Ureaplasma. Discussions are ongoing on the incidence and impact of prenatal, perinatal, and postnatal infection. The present study addressed the impact of Ureaplasma isolates on monocyte-driven inflammation. Methods: Cord blood monocytes of term neonates and adult monocytes, either native or LPS-primed, were cultured with Ureaplasma urealyticum (U. urealyticum) serovar 8 (Uu8) and Ureaplasma parvum serovar 3 (Up3). Using qRT-PCR, cytokine flow cytometry, and multi-analyte immunoassay, we assessed mRNA and protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, IL-12p40, IL-10, and IL-1 receptor antagonist (IL-1ra) as well as Toll-like receptor (TLR) 2 and TLR4. Results: Uu8 and Up3 induced mRNA expression and protein release of TNF-α, IL-1β and IL-8 in term neonatal and adult monocytes (p < 0.01 and p < 0.05). Intracellular protein expression of TNF-α, IL-1β and IL-8 in Ureaplasma-stimulated cells paralleled those results. Ureaplasma-induced cytokine levels did not significantly differ from LPS-mediated levels except for lower intracellular IL-1β in adult monocytes (Uu8: p < 0.05). Remarkably, ureaplasmas did not induce IL-12p40 response and promoted lower amounts of anti-inflammatory IL-10 and IL-1ra than LPS, provoking a cytokine imbalance more in favor of pro-inflammation (IL-1β/IL-10, IL-8/IL-10 and IL-8/IL-1ra: p < 0.01, vs. LPS). In contrast to LPS, both isolates induced TLR2 mRNA in neonatal and adult cells (p < 0.001 and p < 0.05) and suppressed TLR4 mRNA in adult monocytes (p < 0.05). Upon co-stimulation, Uu8 and Up3 inhibited LPS-induced intracellular IL-1β (p < 0.001 and p < 0.05) and IL-8 in adult monocytes (p < 0.01), while LPS-induced neonatal cytokines were maintained or aggravated (p < 0.05). Conclusion: Our data demonstrate a considerable pro-inflammatory capacity of Ureaplasma isolates in human monocytes. Stimulating pro-inflammatory cytokine responses while hardly inducing immunomodulatory and anti-inflammatory cytokines, ureaplasmas might push monocyte immune responses toward pro-inflammation. Inhibition of LPS-induced cytokines in adult monocytes in contrast to sustained inflammation in term neonatal monocytes indicates a differential modulation of host immune responses to a second stimulus. Modification of TLR2 and TLR4 expression may shape host susceptibility to inflammation.}, language = {en} } @article{HeidrichBauriedlBarquistetal.2017, author = {Heidrich, Nadja and Bauriedl, Saskia and Barquist, Lars and Li, Lei and Schoen, Christoph and Vogel, J{\"o}rg}, title = {The primary transcriptome of Neisseria meningitidis and its interaction with the RNA chaperone Hfq}, series = {Nucleic Acids Research}, volume = {45}, journal = {Nucleic Acids Research}, number = {10}, doi = {10.1093/nar/gkx168}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170828}, pages = {6147-6167}, year = {2017}, abstract = {Neisseria meningitidis is a human commensal that can also cause life-threatening meningitis and septicemia. Despite growing evidence for RNA-based regulation in meningococci, their transcriptome structure and output of regulatory small RNAs (sRNAs) are incompletely understood. Using dRNA-seq, we have mapped at single-nucleotide resolution the primary transcriptome of N. meningitidis strain 8013. Annotation of 1625 transcriptional start sites defines transcription units for most protein-coding genes but also reveals a paucity of classical σ70-type promoters, suggesting the existence of activators that compensate for the lack of -35 consensus sequences in N. meningitidis. The transcriptome maps also reveal 65 candidate sRNAs, a third of which were validated by northern blot analysis. Immunoprecipitation with the RNA chaperone Hfq drafts an unexpectedly large post-transcriptional regulatory network in this organism, comprising 23 sRNAs and hundreds of potential mRNA targets. Based on this data, using a newly developed gfp reporter system we validate an Hfq-dependent mRNA repression of the putative colonization factor PrpB by the two trans-acting sRNAs RcoF1/2. Our genome-wide RNA compendium will allow for a better understanding of meningococcal transcriptome organization and riboregulation with implications for colonization of the human nasopharynx.}, language = {en} } @article{HellenbrandClausSchinketal.2016, author = {Hellenbrand, Wiebke and Claus, Heike and Schink, Susanne and Marcus, Ulrich and Wichmann, Ole and Vogel, Ulrich}, title = {Risk of Invasive Meningococcal Disease in Men Who Have Sex with Men: Lessons Learned from an Outbreak in Germany, 2012-2013}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {8}, doi = {10.1371/journal.pone.0160126}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166842}, pages = {e0160126}, year = {2016}, abstract = {Background We undertook investigations in response to an invasive meningococcal disease (IMD) outbreak in men who have sex with men (MSM) in Berlin 2012-2013 to better understand meningococcal transmission and IMD risk in MSM. Methods We retrospectively searched for further IMD cases in MSM in Germany through local health departments and undertook exploratory interviews. We performed antigen sequence typing, characterized fHbp and aniA genes of strains with the outbreak finetype and reviewed epidemiologically or spatiotemporally linked cases from 2002-2014. Results Among the 148 IMD-cases notified from 01.01.2012-30.09.2013 in 18-59 year-old men we identified 13 MSM in 6 federal states: 11 serogroup C (MenC, all finetype C:P1.5-1,10-8:F3-6), 2 MenB. Interviews with 7 MSM revealed frequent meeting of multiple partners online or via mobile apps and illicit drug use as potential risk factors. MenC incidence was 13-fold higher in MSM than non-MSM. MenC isolates from 9/11 MSM had a novel fHbp allele 766. All C:P1.5-1,10-8:F3-6 strains from MSM versus 16/23 from non-MSM had intact aniA genes (p = 0.04). Although definitive evidence for transmission among MSM in epidemiological or spatiotemporal clusters in 2002-2014 was lacking, clusters were more frequent in men aged 20-49 years. Molecular analysis of C:P1.5-1,10-8:F3-6 strains revealed cases with intact aniA since 2007, mainly associated with fHbp361, fHbp766 and fHbp813, all involving one or more MSM. Conclusions MenC incidence was elevated in MSM during the study period. Multiple casual sexual contacts and illicit drug use were common in affected MSM. In all strains from MSM we detected an intact aniA gene coding for a nitrite reductase, which permits survival in microanaerobic environments and could play a role in meningococcal transmission in MSM through urogenital colonization. Furthermore, meningococcal transmission among MSM may be sustained over large areas and thus require modified spatiotemporal scanning algorithms for timely detection and control.}, language = {en} } @article{MachataSreekantapuramHuennigeretal.2021, author = {Machata, Silke and Sreekantapuram, Sravya and H{\"u}nniger, Kerstin and Kurzai, Oliver and Dunker, Christine and Schubert, Katja and Kr{\"u}ger, Wibke and Schulze-Richter, Bianca and Speth, Cornelia and Rambach, G{\"u}nter and Jacobsen, Ilse D.}, title = {Significant Differences in Host-Pathogen Interactions Between Murine and Human Whole Blood}, series = {Frontiers in Immunology}, volume = {11}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2020.565869}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-222575}, year = {2021}, abstract = {Murine infection models are widely used to study systemic candidiasis caused by C. albicans. Whole-blood models can help to elucidate host-pathogens interactions and have been used for several Candida species in human blood. We adapted the human whole-blood model to murine blood. Unlike human blood, murine blood was unable to reduce fungal burden and more substantial filamentation of C. albicans was observed. This coincided with less fungal association with leukocytes, especially neutrophils. The lower neutrophil number in murine blood only partially explains insufficient infection and filamentation control, as spiking with murine neutrophils had only limited effects on fungal killing. Furthermore, increased fungal survival is not mediated by enhanced filamentation, as a filament-deficient mutant was likewise not eliminated. We also observed host-dependent differences for interaction of platelets with C. albicans, showing enhanced platelet aggregation, adhesion and activation in murine blood. For human blood, opsonization was shown to decrease platelet interaction suggesting that complement factors interfere with fungus-to-platelet binding. Our results reveal substantial differences between murine and human whole-blood models infected with C. albicans and thereby demonstrate limitations in the translatability of this ex vivo model between hosts.}, language = {en} } @article{DuskeClausKroneetal.2024, author = {Duske, Helene and Claus, Heike and Krone, Manuel and L{\^a}m, Thi{\^e}n-Tr{\´i}}, title = {Prevalence of piperacillin/tazobactam resistance in invasive \(Haemophilus\) \(influenzae\) in Germany}, series = {JAC-Antimicrobial Resistance}, volume = {6}, journal = {JAC-Antimicrobial Resistance}, number = {1}, issn = {2632-1823}, doi = {10.1093/jacamr/dlad148}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-350424}, year = {2024}, abstract = {Background Haemophilus influenzae (Hi) is a Gram-negative bacterium that may cause sepsis or meningitis, treatment of which mainly includes β-lactam antibiotics. Since 2019 EUCAST breakpoints for piperacillin/tazobactam have been available. Little is known about the prevalence and mechanisms of piperacillin/tazobactam resistance in Hi. Objectives To provide reliable prevalence data for piperacillin/tazobactam resistance in Hi in Germany, to evaluate different antibiotic susceptibility testing methods and to examine possible resistance mechanisms. Methods According to EUCAST breakpoints, the MIC for piperacillin/tazobactam resistance is >0.25 mg/L. All invasive Hi in Germany from 2019 were examined by gradient agar diffusion (GAD) for piperacillin/tazobactam susceptibility. Piperacillin/tazobactam broth microdilution (BMD), piperacillin GAD on tazobactam-containing agar [piperacillin GAD on Mueller-Hinton agar with horse blood (MH-F)/tazobactam) and piperacillin/tazobactam agar dilution (AD) were used for confirmation. Phenotypic testing was complemented by ftsI sequencing. Results Piperacillin/tazobactam GAD resulted in 2.9\% (21/726) resistant Hi. BMD did not confirm piperacillin/tazobactam resistance. Two strains were found resistant by AD, of which one was also resistant using piperacillin GAD on MH-F/tazobactam. Overall, we found two strains with a piperacillin/tazobactam MIC >0.25 mg/L in at least two different tests (0.3\%). Both were β-lactamase-producing amoxicillin/clavulanate-resistant with PBP3 mutations characterized as group III-like+. Relevant PBP3 mutations occurred in six strains without phenotypic piperacillin/tazobactam resistance. These mutations suggest a reduced efficacy of β-lactam antibiotics in these isolates. Conclusions Piperacillin/tazobactam resistance prevalence in invasive Hi is low in Germany. Reduced susceptibility was correlated with PBP3 mutations, in particular with group III mutations.}, language = {en} } @phdthesis{Endres2024, author = {Endres, Leo Maximilian}, title = {Development of multicellular \(in\) \(vitro\) models of the meningeal blood-CSF barrier to study \(Neisseria\) \(meningitidis\) infection}, doi = {10.25972/OPUS-34621}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-346216}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Neisseria meningitidis (the meningococcus) is one of the major causes of bacterial meningitis, a life-threatening inflammation of the meninges. Traversal of the meningeal blood-cerebrospinal fluid barrier (mBCSFB), which is composed of highly specialized brain endothelial cells (BECs), and subsequent interaction with leptomeningeal cells (LMCs) are critical for disease progression. Due to the human-exclusive tropism of N. meningitidis, research on this complex host-pathogen interaction is mostly limited to in vitro studies. Previous studies have primarily used peripheral or immortalized BECs alone, which do not retain relevant barrier phenotypes in culture. To study meningococcal interaction with the mBCSFB in a physiologically more accurate context, BEC-LMC co-culture models were developed in this project using BEC-like cells derived from induced pluripotent stem cells (iBECs) or hCMEC/D3 cells in combination with LMCs derived from tumor biopsies. Distinct BEC and LMC layers as well as characteristic expression of cellular markers were observed using transmission electron microscopy (TEM) and immunofluorescence staining. Clear junctional expression of brain endothelial tight and adherens junction proteins was detected in the iBEC layer. LMC co-culture increased iBEC barrier tightness and stability over a period of seven days, as determined by sodium fluorescein (NaF) permeability and transendothelial electrical resistance (TEER). Infection experiments demonstrated comparable meningococcal adhesion and invasion of the BEC layer in all models tested, consistent with previously published data. While only few bacteria crossed the iBEC-LMC barrier initially, transmigration rates increased substantially over 24 hours, despite constant high TEER. After 24 hours of infection, deterioration of the barrier properties was observed including loss of TEER and altered expression of tight and adherens junction components. Reduced mRNA levels of ZO-1, claudin-5, and VE-cadherin were detected in BECs from all models. qPCR and siRNA knockdown data suggested that transcriptional downregulation of these genes was potentially but not solely mediated by Snail1. Immunofluorescence staining showed reduced junctional coverage of occludin, indicating N. meningitidis-induced post-transcriptional modulation of this protein, as previous studies have suggested. Together, these results suggest a potential combination of transcellular and paracellular meningococcal traversal of the mBCSFB, with the more accessible paracellular route becoming available upon barrier disruption after prolonged N. meningitidis infection. Finally, N. meningitidis induced cellular expression of pro-inflammatory cytokines and chemokines such as IL-8 in all mBCSFB models. Overall, the work described in this thesis highlights the usefulness of advanced in vitro models of the mBCSFB that mimic native physiology and exhibit relevant barrier properties to study infection with meningeal pathogens such as N. meningitidis.}, subject = {Bakterielle Hirnhautentz{\"u}ndung}, language = {en} } @article{DichtlKocForsteretal.2021, author = {Dichtl, Karl and Koc, {\"O}zlem and Forster, Johannes and Scharf, Christina and Suerbaum, Sebastian and Andrassy, Joachim and Wagener, Johannes and Schroeder, Ines}, title = {An invasive infection caused by the thermophilic mold Talaromyces thermophilus}, series = {Infection}, volume = {49}, journal = {Infection}, number = {6}, issn = {0300-8126}, doi = {10.1007/s15010-021-01648-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-308970}, pages = {1347-1353}, year = {2021}, abstract = {Background Increasing incidence of invasive infections caused by rare fungi was observed over the recent years. Case Here, we describe the first reported case of an infection caused by the thermophilic mold Talaromyces thermophilus. Cultivation and, hence, identification of this fastidious organism is challenging since standard incubation conditions are not sufficient. Retrospective analysis of patient samples and in vitro experiments demonstrated that testing for fungal antigens, i.e., the cell wall components galactomannan and β-1,3-D-glucan, is a promising tool.}, language = {en} } @phdthesis{Ulrich2024, author = {Ulrich, Johannes}, title = {Molekulare Charaktierisierung einer DyP-Typ Peroxidase des Humanparasiten \(Echinococcus\) \(multilocularis\)}, doi = {10.25972/OPUS-35714}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357143}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2024}, abstract = {Die Alveol{\"a}re Echinokokkose (AE) ist eine t{\"o}dliche Infektionserkrankung, die durch den parasit{\"a}ren Plattwurm Echinococcus multilocularis verursacht wird. Genomanalysen von E. multilocularis ergaben ein Gen, das laut Vorhersage f{\"u}r eine DyP-Typ Peroxidase codiere. Ziel dieser Arbeit ist die biologische Funktion des codierten Enzyms besser zu verstehen und Hinweise auf eine m{\"o}gliche Rolle in der Abwehr von Reaktiven Sauerstoffspezies (ROS) zu erlangen. Das Gen wurde heterolog in E. Coli exprimiert und molekulare Charakteristika des Gens mit bioinformatischen und molekularbiologischen Methoden untersucht. Quantitative RT-PCR Untersuchungen gaben Aufschluss {\"u}ber das Transkriptprofil von emipox in unterschiedlichen Entwicklungsstadien von E. mulitlocularis. Mittels Whole-Mount In Situ-Hybridisierung (WMISH) wurden die Transkripte zudem lokalisiert und ihre Beziehung zum Stammzellsystem von E. multilocularis n{\"a}her untersucht. Die Zugeh{\"o}rigkeit von EmIPOX zur Gruppe der DyP-Typ Peroxidasen wurde best{\"a}tigt. Homologe beim Menschen kommen nicht vor. Es konnte nachgewiesen werden, dass Transkripte von emipox auch, aber keinesfalls ausschließlich, in Stammzellen vorliegen. {\"U}berdurchschnittlich viele Transkripte liegen im aktivierten Protoscolex und im Metacestoden ex vivo aus einer infizierten Wirtsleber vor. Untersuchungen zur Enzymaktivit{\"a}t von EmIPOX zeigten neben einer Peroxidase- auch eine Katalaseaktivit{\"a}t. Die vorliegende Arbeit ist die erste Charakterisierung einer DyP-Typ Peroxidase bei Tieren. Sie legt nahe, dass EmIPOX eine Rolle in der Entgiftung von ROS in E. multilocularis spielt und stellt den Charakter von EmIPOX als potenzieller pharmakologischer Zielstruktur heraus.}, subject = {Fuchsbandwurm}, language = {de} } @article{SchlesingerWeissbrichWedekinketal.2020, author = {Schlesinger, Tobias and Weißbrich, Benedikt and Wedekink, Florian and Notz, Quirin and Herrmann, Johannes and Krone, Manuel and Sitter, Magdalena and Schmid, Benedikt and Kredel, Markus and Stumpner, Jan and D{\"o}lken, Lars and Wischhusen, J{\"o}rg and Kranke, Peter and Meybohm, Patrick and Lotz, Christpher}, title = {Biodistribution and serologic response in SARS-CoV-2 induced ARDS: A cohort study}, series = {PLoS One}, volume = {15, 2020}, journal = {PLoS One}, number = {11}, doi = {10.1371/journal.pone.0242917}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231348}, year = {2020}, abstract = {Background The viral load and tissue distribution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remain important questions. The current study investigated SARS-CoV-2 viral load, biodistribution and anti-SARS-CoV-2 antibody formation in patients suffering from severe corona virus disease 2019 (COVID-19) induced acute respiratory distress syndrome (ARDS). Methods This is a retrospective single-center study in 23 patients with COVID-19-induced ARDS. Data were collected within routine intensive care. SARS-CoV-2 viral load was assessed via reverse transcription quantitative polymerase chain reaction (RT-qPCR). Overall, 478 virology samples were taken. Anti-SARS-CoV-2-Spike-receptor binding domain (RBD) antibody detection of blood samples was performed with an enzyme-linked immunosorbent assay. Results Most patients (91\%) suffered from severe ARDS during ICU treatment with a 30-day mortality of 30\%. None of the patients received antiviral treatment. Tracheal aspirates tested positive for SARS-CoV-2 in 100\% of the cases, oropharyngeal swabs only in 77\%. Blood samples were positive in 26\% of the patients. No difference of viral load was found in tracheal or blood samples with regard to 30-day survival or disease severity. SARS-CoV-2 was never found in dialysate. Serologic testing revealed significantly lower concentrations of SARS-CoV-2 neutralizing IgM and IgA antibodies in survivors compared to non-survivors (p = 0.009). Conclusions COVID-19 induced ARDS is accompanied by a high viral load of SARS-CoV-2 in tracheal aspirates, which remained detectable in the majority throughout intensive care treatment. Remarkably, SARS-CoV-2 RNA was never detected in dialysate even in patients with RNAemia. Viral load or the buildup of neutralizing antibodies was not associated with 30-day survival or disease severity.}, language = {en} } @article{FlemmingHankirErnestusetal.2020, author = {Flemming, S. and Hankir, M. and Ernestus, R.-I. and Seyfried, F. and Germer, C.-T. and Meybohm, P. and Wurmb, T. and Vogel, U. and Wiegering, A.}, title = {Surgery in times of COVID-19 — recommendations for hospital and patient management}, series = {Langenbeck's Archives of Surgery}, volume = {405}, journal = {Langenbeck's Archives of Surgery}, issn = {1435-2443}, doi = {10.1007/s00423-020-01888-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-231766}, pages = {359-364}, year = {2020}, abstract = {Background The novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), has escalated rapidly to a global pandemic stretching healthcare systems worldwide to their limits. Surgeonshave had to immediately react to this unprecedented clinical challenge by systematically repurposing surgical wards. Purpose To provide a detailed set of guidelines developed in a surgical ward at University Hospital Wuerzburg to safelyaccommodate the exponentially rising cases of SARS-CoV-2 infected patients without compromising the care of emergencysurgery and oncological patients or jeopardizing the well-being of hospital staff. Conclusions The dynamic prioritization of SARS-CoV-2 infected and surgical patient groups is key to preserving life whilemaintaining high surgical standards. Strictly segregating patient groups in emergency rooms, non-intensive care wards andoperating areas prevents viral spread while adequately training and carefully selecting hospital staff allow them to confidentlyand successfully undertake their respective clinical duties.}, language = {en} } @article{BeierleSchobelVogeletal.2021, author = {Beierle, Felix and Schobel, Johannes and Vogel, Carsten and Allgaier, Johannes and Mulansky, Lena and Haug, Fabian and Haug, Julian and Schlee, Winfried and Holfelder, Marc and Stach, Michael and Schickler, Marc and Baumeister, Harald and Cohrdes, Caroline and Deckert, J{\"u}rgen and Deserno, Lorenz and Edler, Johanna-Sophie and Eichner, Felizitas A. and Greger, Helmut and Hein, Grit and Heuschmann, Peter and John, Dennis and Kestler, Hans A. and Krefting, Dagmar and Langguth, Berthold and Meybohm, Patrick and Probst, Thomas and Reichert, Manfred and Romanos, Marcel and St{\"o}rk, Stefan and Terhorst, Yannik and Weiß, Martin and Pryss, R{\"u}diger}, title = {Corona Health — A Study- and Sensor-Based Mobile App Platform Exploring Aspects of the COVID-19 Pandemic}, series = {International Journal of Environmental Research and Public Health}, volume = {18}, journal = {International Journal of Environmental Research and Public Health}, number = {14}, issn = {1660-4601}, doi = {10.3390/ijerph18147395}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-242658}, year = {2021}, abstract = {Physical and mental well-being during the COVID-19 pandemic is typically assessed via surveys, which might make it difficult to conduct longitudinal studies and might lead to data suffering from recall bias. Ecological momentary assessment (EMA) driven smartphone apps can help alleviate such issues, allowing for in situ recordings. Implementing such an app is not trivial, necessitates strict regulatory and legal requirements, and requires short development cycles to appropriately react to abrupt changes in the pandemic. Based on an existing app framework, we developed Corona Health, an app that serves as a platform for deploying questionnaire-based studies in combination with recordings of mobile sensors. In this paper, we present the technical details of Corona Health and provide first insights into the collected data. Through collaborative efforts from experts from public health, medicine, psychology, and computer science, we released Corona Health publicly on Google Play and the Apple App Store (in July 2020) in eight languages and attracted 7290 installations so far. Currently, five studies related to physical and mental well-being are deployed and 17,241 questionnaires have been filled out. Corona Health proves to be a viable tool for conducting research related to the COVID-19 pandemic and can serve as a blueprint for future EMA-based studies. The data we collected will substantially improve our knowledge on mental and physical health states, traits and trajectories as well as its risk and protective factors over the course of the COVID-19 pandemic and its diverse prevention measures.}, language = {en} } @article{CucherMaricontiManciullietal.2023, author = {Cucher, Marcela A. and Mariconti, Mara and Manciulli, Tommaso and Vola, Ambra and Rosenzvit, Mara C. and Brehm, Klaus and Kamenetzky, Laura and Brunetti, Enrico}, title = {Circulating small RNA profiling of patients with alveolar and cystic echinococcosis}, series = {Biology}, volume = {12}, journal = {Biology}, number = {5}, issn = {2079-7737}, doi = {10.3390/biology12050715}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-319270}, year = {2023}, abstract = {Alveolar (AE) and cystic (CE) echinococcosis are two parasitic diseases caused by the tapeworms Echinococcus multilocularis and E. granulosus sensu lato (s. l.), respectively. Currently, AE and CE are mainly diagnosed by means of imaging techniques, serology, and clinical and epidemiological data. However, no viability markers that indicate parasite state during infection are available. Extracellular small RNAs (sRNAs) are short non-coding RNAs that can be secreted by cells through association with extracellular vesicles, proteins, or lipoproteins. Circulating sRNAs can show altered expression in pathological states; hence, they are intensively studied as biomarkers for several diseases. Here, we profiled the sRNA transcriptomes of AE and CE patients to identify novel biomarkers to aid in medical decisions when current diagnostic procedures are inconclusive. For this, endogenous and parasitic sRNAs were analyzed by sRNA sequencing in serum from disease negative, positive, and treated patients and patients harboring a non-parasitic lesion. Consequently, 20 differentially expressed sRNAs associated with AE, CE, and/or non-parasitic lesion were identified. Our results represent an in-depth characterization of the effect E. multilocularis and E. granulosus s. l. exert on the extracellular sRNA landscape in human infections and provide a set of novel candidate biomarkers for both AE and CE detection.}, language = {en} } @article{WeissGruendahlDeckertetal.2023, author = {Weiß, Martin and Gr{\"u}ndahl, Marthe and Deckert, J{\"u}rgen and Eichner, Felizitas A. and Kohls, Mirjam and St{\"o}rk, Stefan and Heuschmann, Peter U. and Hein, Grit}, title = {Differential network interactions between psychosocial factors, mental health, and health-related quality of life in women and men}, series = {Scientific Reports}, volume = {13}, journal = {Scientific Reports}, organization = {STAAB-COVID Study Group}, doi = {10.1038/s41598-023-38525-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357858}, year = {2023}, abstract = {Psychosocial factors affect mental health and health-related quality of life (HRQL) in a complex manner, yet gender differences in these interactions remain poorly understood. We investigated whether psychosocial factors such as social support and personal and work-related concerns impact mental health and HRQL differentially in women and men during the first year of the COVID-19 pandemic. Between June and October 2020, the first part of a COVID-19-specific program was conducted within the "Characteristics and Course of Heart Failure Stages A-B and Determinants of Progression (STAAB)" cohort study, a representative age- and gender-stratified sample of the general population of W{\"u}rzburg, Germany. Using psychometric networks, we first established the complex relations between personal social support, personal and work-related concerns, and their interactions with anxiety, depression, and HRQL. Second, we tested for gender differences by comparing expected influence, edge weight differences, and stability of the networks. The network comparison revealed a significant difference in the overall network structure. The male (N = 1370) but not the female network (N = 1520) showed a positive link between work-related concern and anxiety. In both networks, anxiety was the most central variable. These findings provide further evidence that the complex interplay of psychosocial factors with mental health and HRQL decisively depends on gender. Our results are relevant for the development of gender-specific interventions to increase resilience in times of pandemic crisis.}, language = {en} } @article{HaederSchaeubleGehlenetal.2023, author = {H{\"a}der, Antje and Sch{\"a}uble, Sascha and Gehlen, Jan and Thielemann, Nadja and Buerfent, Benedikt C. and Sch{\"u}ller, Vitalia and Hess, Timo and Wolf, Thomas and Schr{\"o}der, Julia and Weber, Michael and H{\"u}nniger, Kerstin and L{\"o}ffler, J{\"u}rgen and Vylkova, Slavena and Panagiotou, Gianni and Schumacher, Johannes and Kurzai, Oliver}, title = {Pathogen-specific innate immune response patterns are distinctly affected by genetic diversity}, series = {Nature Communications}, volume = {14}, journal = {Nature Communications}, doi = {10.1038/s41467-023-38994-5}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-357441}, year = {2023}, abstract = {Innate immune responses vary by pathogen and host genetics. We analyze quantitative trait loci (eQTLs) and transcriptomes of monocytes from 215 individuals stimulated by fungal, Gram-negative or Gram-positive bacterial pathogens. We identify conserved monocyte responses to bacterial pathogens and a distinct antifungal response. These include 745 response eQTLs (reQTLs) and corresponding genes with pathogen-specific effects, which we find first in samples of male donors and subsequently confirm for selected reQTLs in females. reQTLs affect predominantly upregulated genes that regulate immune response via e.g., NOD-like, C-type lectin, Toll-like and complement receptor-signaling pathways. Hence, reQTLs provide a functional explanation for individual differences in innate response patterns. Our identified reQTLs are also associated with cancer, autoimmunity, inflammatory and infectious diseases as shown by external genome-wide association studies. Thus, reQTLs help to explain interindividual variation in immune response to infection and provide candidate genes for variants associated with a range of diseases.}, language = {en} } @article{SchreiberLohrBaltesetal.2023, author = {Schreiber, Laura M. and Lohr, David and Baltes, Steffen and Vogel, Ulrich and Elabyad, Ibrahim A. and Bille, Maya and Reiter, Theresa and Kosmala, Aleksander and Gassenmaier, Tobias and Stefanescu, Maria R. and Kollmann, Alena and Aures, Julia and Schnitter, Florian and Pali, Mihaela and Ueda, Yuichiro and Williams, Tatiana and Christa, Martin and Hofmann, Ulrich and Bauer, Wolfgang and Gerull, Brenda and Zernecke, Alma and Erg{\"u}n, S{\"u}leyman and Terekhov, Maxim}, title = {Ultra-high field cardiac MRI in large animals and humans for translational cardiovascular research}, series = {Frontiers in Cardiovascular Medicine}, volume = {10}, journal = {Frontiers in Cardiovascular Medicine}, issn = {2297-055X}, doi = {10.3389/fcvm.2023.1068390}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-317398}, year = {2023}, abstract = {A key step in translational cardiovascular research is the use of large animal models to better understand normal and abnormal physiology, to test drugs or interventions, or to perform studies which would be considered unethical in human subjects. Ultrahigh field magnetic resonance imaging (UHF-MRI) at 7 T field strength is becoming increasingly available for imaging of the heart and, when compared to clinically established field strengths, promises better image quality and image information content, more precise functional analysis, potentially new image contrasts, and as all in-vivo imaging techniques, a reduction of the number of animals per study because of the possibility to scan every animal repeatedly. We present here a solution to the dual use problem of whole-body UHF-MRI systems, which are typically installed in clinical environments, to both UHF-MRI in large animals and humans. Moreover, we provide evidence that in such a research infrastructure UHF-MRI, and ideally combined with a standard small-bore UHF-MRI system, can contribute to a variety of spatial scales in translational cardiovascular research: from cardiac organoids, Zebra fish and rodent hearts to large animal models such as pigs and humans. We present pilot data from serial CINE, late gadolinium enhancement, and susceptibility weighted UHF-MRI in a myocardial infarction model over eight weeks. In 14 pigs which were delivered from a breeding facility in a national SARS-CoV-2 hotspot, we found no infection in the incoming pigs. Human scanning using CINE and phase contrast flow measurements provided good image quality of the left and right ventricle. Agreement of functional analysis between CINE and phase contrast MRI was excellent. MRI in arrested hearts or excised vascular tissue for MRI-based histologic imaging, structural imaging of myofiber and vascular smooth muscle cell architecture using high-resolution diffusion tensor imaging, and UHF-MRI for monitoring free radicals as a surrogate for MRI of reactive oxygen species in studies of oxidative stress are demonstrated. We conclude that UHF-MRI has the potential to become an important precision imaging modality in translational cardiovascular research.}, language = {en} } @article{SilwedelSpeerHaarmannetal.2019, author = {Silwedel, Christine and Speer, Christian P. and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Schlegel, Nicolas and Glaser, Kirsten}, title = {Ureaplasma species modulate cytokine and chemokine responses in human brain microvascular endothelial cells}, series = {International Journal of Molecular Science}, volume = {20}, journal = {International Journal of Molecular Science}, number = {14}, issn = {1422-0067}, doi = {10.3390/ijms20143583}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201848}, year = {2019}, abstract = {Ureaplasma species are common colonizers of the adult genitourinary tract and often considered as low-virulence commensals. Intraamniotic Ureaplasma infections, however, facilitate chorioamnionitis and preterm birth, and cases of Ureaplasma-induced neonatal sepsis, pneumonia, and meningitis raise a growing awareness of their clinical relevance. In vitro studies are scarce but demonstrate distinct Ureaplasma-driven impacts on immune mechanisms. The current study addressed cytokine and chemokine responses upon exposure of native or lipopolysaccharide (LPS) co-stimulated human brain microvascular endothelial cells (HBMEC) to Ureaplasma urealyticum or U. parvum, using qRT-PCR, RNA sequencing, multi-analyte immunoassay, and flow cytometry. Ureaplasma exposure in native HBMEC reduced monocyte chemoattractant protein (MCP)-3 mRNA expression (p < 0.01, vs. broth). In co-stimulated HBMEC, Ureaplasma spp. attenuated LPS-evoked mRNA responses for C-X-C chemokine ligand 5, MCP-1, and MCP-3 (p < 0.05, vs. LPS) and mitigated LPS-driven interleukin (IL)-1α protein secretion, as well as IL-8 mRNA and protein responses (p < 0.05). Furthermore, Ureaplasma isolates increased C-X-C chemokine receptor 4 mRNA levels in native and LPS co-stimulated HBMEC (p < 0.05). The presented results may imply immunomodulatory capacities of Ureaplasma spp. which may ultimately promote chronic colonization and long-term neuroinflammation.}, language = {en} } @article{KruegerLeskienSchulleretal.2021, author = {Kr{\"u}ger, S{\"o}ren and Leskien, Miriam and Schuller, Patricia and Prifert, Christiane and Weißbrich, Benedikt and Vogel, Ulrich and Krone, Manuel}, title = {Performance and feasibility of universal PCR admission screening for SARS-CoV-2 in a German tertiary care hospital}, series = {Journal of Medical Virology}, volume = {93}, journal = {Journal of Medical Virology}, number = {5}, doi = {10.1002/jmv.26770}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238971}, pages = {2890 -- 2898}, year = {2021}, abstract = {Anamnestic screening of symptoms and contact history is applied to identify coronavirus disease 2019 (COVID-19) patients on admission. However, asymptomatic and presymptomatic patients remain undetected although the viral load may be high. In this retrospective cohort study, all hospitalized patients who received polymerase chain reaction (PCR) admission testing from March 26th until May 24th, 2020 were included. Data on COVID-19-specific symptoms and contact history to COVID-19 cases were retrospectively extracted from patient files and from contact tracing notes. The compliance to the universal testing protocol was high with 90\%. Out of 6940 tested patients, 27 new severe acute respiratory syndrome coronavirus-2 infections (0.4\%) were detected. Seven of those COVID-19 cases (26\% of all new cases) were asymptomatic and had no positive contact history, but were identified through a positive PCR test. The number needed to identify an asymptomatic patient was 425 in the first wave of the epidemic, 1218 in the low incidence phase. The specificity of the method was above 99.9\%. Universal PCR testing was highly accepted by staff as demonstrated by high compliance. The costs to detect one asymptomatic case in future studies need to be traded off against the costs and damage caused by potential outbreaks of COVID-19.}, language = {en} } @article{SpringerHeldMengolietal.2021, author = {Springer, Jan and Held, J{\"u}rgen and Mengoli, Carlo and Schlegel, Paul Gerhardt and Gamon, Florian and Tr{\"a}ger, Johannes and Kurzai, Oliver and Einsele, Hermann and Loeffler, Juergen and Eyrich, Matthias}, title = {Diagnostic performance of (1→3)-β-D-glucan alone and in combination with aspergillus PCR and galactomannan in serum of pediatric patients after allogeneic hematopoietic stem cell transplantation}, series = {Journal of Fungi}, volume = {7}, journal = {Journal of Fungi}, number = {3}, issn = {2309-608X}, doi = {10.3390/jof7030238}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-234179}, year = {2021}, abstract = {Data on biomarker-assisted diagnosis of invasive aspergillosis (IA) in pediatric patients is scarce. Therefore, we conducted a cohort study over two years including 404 serum specimens of 26 pediatric patients after allogeneic hematopoietic stem cell transplantation (alloSCT). Sera were tested prospectively twice weekly for Aspergillus-specific DNA, galactomannan (GM), and retrospectively for (1→3)-β-D-glucan (BDG). Three probable IA and two possible invasive fungal disease (IFD) cases were identified using the European Organization for Research and Treatment of Cancer and the Mycoses Study Group (EORTC/MSGERC) 2019 consensus definitions. Sensitivity and specificity for diagnosis of probable IA and possible IFD was 80\% (95\% confidential interval (CI): 28-99\%) and 55\% (95\% CI: 32-77\%) for BDG, 40\% (95\% CI: 5-85\%) and 100\% (95\% CI: 83-100\%) for GM, and 60\% (95\% CI: 15-95\%) and 95\% (95\% CI: 75-100\%) for Aspergillus-specific real-time PCR. However, sensitivities have to be interpreted with great caution due to the limited number of IA cases. Interestingly, the low specificity of BDG was largely caused by false-positive BDG results that clustered around the date of alloSCT. The following strategies were able to increase BDG specificity: two consecutive positive BDG tests for diagnosis (specificity 80\% (95\% CI: 56-94\%)); using an optimized cutoff value of 306 pg/mL (specificity 90\% (95\% CI: 68-99\%)) and testing BDG only after the acute posttransplant phase. In summary, BDG can help to diagnose IA in pediatric alloSCT recipients. However, due to the poor specificity either an increased cutoff value should be utilized or BDG results should be confirmed by an alternative Aspergillus assay.}, language = {en} } @article{MottolaRamirezZavalaHuenningeretal.2021, author = {Mottola, Austin and Ram{\´i}rez-Zavala, Bernardo and H{\"u}nninger, Kerstin and Kurzai, Oliver and Morschh{\"a}user, Joachim}, title = {The zinc cluster transcription factor Czf1 regulates cell wall architecture and integrity in Candida albicans}, series = {Molecular Microbiology}, volume = {116}, journal = {Molecular Microbiology}, number = {2}, doi = {10.1111/mmi.14727}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259583}, pages = {483-497}, year = {2021}, abstract = {The fungal cell wall is essential for the maintenance of cellular integrity and mediates interactions of the cells with the environment. It is a highly flexible organelle whose composition and organization is modulated in response to changing growth conditions. In the pathogenic yeast Candida albicans, a network of signaling pathways regulates the structure of the cell wall, and mutants with defects in these pathways are hypersensitive to cell wall stress. By harnessing a library of genetically activated forms of all C. albicans zinc cluster transcription factors, we found that a hyperactive Czf1 rescued the hypersensitivity to cell wall stress of different protein kinase deletion mutants. The hyperactive Czf1 induced the expression of many genes with cell wall-related functions and caused visible changes in the cell wall structure. C. albicans czf1Δ mutants were hypersensitive to the antifungal drug caspofungin, which inhibits cell wall biosynthesis. The changes in cell wall architecture caused by hyperactivity or absence of Czf1 resulted in an increased recognition of C. albicans by human neutrophils. Our results show that Czf1, which is known as a regulator of filamentous growth and white-opaque switching, controls the expression of cell wall genes and modulates the architecture of the cell wall.}, language = {en} } @article{DickKraussHillenkampetal.2017, author = {Dick, Julia and Krauß, Patrizia and Hillenkamp, Jost and Kohlmorgen, Britta and Schoen, Christoph}, title = {Postoperative Tropheryma whipplei endophthalmitis - a case report highlighting the additive value of molecular testing}, series = {JMM Case Reports}, volume = {4}, journal = {JMM Case Reports}, doi = {10.1099/jmmcr.0.005124}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158823}, pages = {e005124}, year = {2017}, abstract = {Introduction. Tropheryma whipplei is the causative agent of Whipple's disease. Gastrointestinal and lymphatic tissues are affected in the majority of cases, resulting in diarrhoea, malabsorption and fever. Here, we report a rare case of ocular manifestation in a patient lacking the typical Whipple symptoms. Case presentation. A 74-year-old Caucasian female presented with blurred vision in the right eye over a period of 1-2 months, accompanied by stinging pain and conjunctival hyperaemia for the last 2 days. Upon admission, visual acuity was hand motion in the affected eye. Ophthalmological examination showed typical signs of intraocular inflammation. Diagnostic and therapeutic pars plana vitrectomy including vitreous biopsy and intravitreal instillation of vancomycin and amikacin was performed within hours of initial presentation. Both microscopic analysis and microbial cultures of the vitreous biopsy remained negative for bacteria and fungi. The postoperative antibiotic regime included intravenous administration of ceftriaxone in combination with topical tobramycin and ofloxacin. Due to the empirical therapy the inflammation ceased and the patient was discharged after 5 days with cefpodoxime orally and local antibiotic and steroidal therapy. Meanwhile, the vitreous body had undergone testing by PCR for the eubacterial 16S rRNA gene, which was found to be positive. Analysis of the PCR product revealed a specific sequence of T. whipplei. Conclusion. In our patient, endophthalmitis was the first and only symptom of Morbus Whipple, while most patients with Whipple's disease suffer from severe gastrointestinal symptoms. 16S rDNA PCR should be considered for any intraocular infection when microscopy and standard culture methods remain negative.}, language = {en} } @article{TappeLauruschkatStrobeletal.2022, author = {Tappe, Beeke and Lauruschkat, Chris D. and Strobel, Lea and Pantale{\´o}n Garc{\´i}a, Jezreel and Kurzai, Oliver and Rebhan, Silke and Kraus, Sabrina and Pfeuffer-Jovic, Elena and Bussemer, Lydia and Possler, Lotte and Held, Matthias and H{\"u}nniger, Kerstin and Kniemeyer, Olaf and Sch{\"a}uble, Sascha and Brakhage, Axel A. and Panagiotou, Gianni and White, P. Lewis and Einsele, Hermann and L{\"o}ffler, J{\"u}rgen and Wurster, Sebastian}, title = {COVID-19 patients share common, corticosteroid-independent features of impaired host immunity to pathogenic molds}, series = {Frontiers in Immunology}, volume = {13}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2022.954985}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-283558}, year = {2022}, abstract = {Patients suffering from coronavirus disease-2019 (COVID-19) are susceptible to deadly secondary fungal infections such as COVID-19-associated pulmonary aspergillosis and COVID-19-associated mucormycosis. Despite this clinical observation, direct experimental evidence for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-driven alterations of antifungal immunity is scarce. Using an ex-vivo whole blood stimulation assay, we challenged blood from twelve COVID-19 patients with Aspergillus fumigatus and Rhizopus arrhizus antigens and studied the expression of activation, maturation, and exhaustion markers, as well as cytokine secretion. Compared to healthy controls, T-helper cells from COVID-19 patients displayed increased expression levels of the exhaustion marker PD-1 and weakened A. fumigatus- and R. arrhizus-induced activation. While baseline secretion of proinflammatory cytokines was massively elevated, whole blood from COVID-19 patients elicited diminished release of T-cellular (e.g., IFN-γ, IL-2) and innate immune cell-derived (e.g., CXCL9, CXCL10) cytokines in response to A. fumigatus and R. arrhizus antigens. Additionally, samples from COVID-19 patients showed deficient granulocyte activation by mold antigens and reduced fungal killing capacity of neutrophils. These features of weakened anti-mold immune responses were largely decoupled from COVID-19 severity, the time elapsed since diagnosis of COVID-19, and recent corticosteroid uptake, suggesting that impaired anti-mold defense is a common denominator of the underlying SARS-CoV-2 infection. Taken together, these results expand our understanding of the immune predisposition to post-viral mold infections and could inform future studies of immunotherapeutic strategies to prevent and treat fungal superinfections in COVID-19 patients.}, language = {en} } @article{SpringerWaltherRickertsetal.2019, author = {Springer, Jan and Walther, Grit and Rickerts, Volker and Hamprecht, Axel and Willinger, Birgit and Teschner, Daniel and Einsele, Hermann and Kurzai, Oliver and Loeffler, Juergen}, title = {Detection of Fusarium Species in Clinical Specimens by Probe-Based Real-Time PCR}, series = {Journal of Fungi}, volume = {5}, journal = {Journal of Fungi}, number = {4}, issn = {2309-608X}, doi = {10.3390/jof5040105}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193111}, pages = {105}, year = {2019}, abstract = {The mold Fusarium is a ubiquitous fungus causing plant, animal and human infections. In humans, Fusarium spp. are the major cause of eye infections in patients wearing contact lenses or after local trauma. Systemic infections by Fusarium spp. mainly occur in immunosuppressed patients and can disseminate throughout the human body. Due to high levels of resistance to antifungals a fast identification of the causative agent is an urgent need. By using a probe-based real-time PCR assay specific for the genus Fusarium we analysed several different clinical specimens detecting Fusarium spp. commonly found in clinical samples in Germany. Also, a large collection of lung fluid samples of haematological patients was analysed (n = 243). In these, two samples (0.8\%) were reproducibly positive, but only one could be confirmed by sequencing. For this case of probable invasive fungal disease (IFD) culture was positive for Fusarium species. Here we describe a rapid, probe-based real-time PCR assay to specifically detect DNA from a broad range of Fusarium species and its application to clinically relevant specimens.}, language = {en} } @article{MoremiClausVogeletal.2017, author = {Moremi, Nyambura and Claus, Heike and Vogel, Ulrich and Mshana, Stephen E.}, title = {Faecal carriage of CTX-M extended-spectrum beta-lactamase-producing Enterobacteriaceae among street children dwelling in Mwanza city, Tanzania}, series = {PLoS ONE}, volume = {12}, journal = {PLoS ONE}, number = {9}, doi = {10.1371/journal.pone.0184592}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-170331}, pages = {e0184592}, year = {2017}, abstract = {Background Data on ESBL carriage of healthy people including children are scarce especially in developing countries. We analyzed the prevalence and genotypes of ESBL-producing Enterobacteriaceae (EPE) in Tanzanian street children with rare contact to healthcare facilities but significant interactions with the environment, animals and other people. Methodology/ Principle findings Between April and July 2015, stool samples of 107 street children, who live in urban Mwanza were analyzed for EPE. Intestinal carriage of EPE was found in 34 (31.8\%, 95\% CI; 22.7-40.3) children. Of the 36 isolates from 34 children, 30 (83.3\%) were Escherichia coli (E. coli) and six Klebsiella pneumoniae (K. pneumoniae). Out of 36 isolates, 36 (100\%), 35 (97\%), 25 (69\%) and 16 (44\%) were resistant to tetracycline, trimethoprim-sulfamethoxazole, ciprofloxacin and gentamicin, respectively. Beta-lactamase genes and the multilocus sequence types of E. coli and K. pneumoniae were characterized. ESBL gene bla\(_{CTX-M-15}\) was detected in 75\% (27/36) of ESBL isolates. Sequence types (STs) 131, 10, 448 and 617 were the most prevalent in E. coli. Use of local herbs (OR: 3.5, 95\% CI: 1.51-8.08, P = 0.003) and spending day and night on streets (OR: 3.6, 95\% CI: 1.44-8.97, P = 0.005) were independent predictors of ESBL carriage. Conclusions/ Significance We observed a high prevalence of bla\(_{CTX-M-15}\) in EPE collected from street children in Tanzania. Detection of E. coli STs 131, 10, 38 and 648, which have been observed worldwide in animals and people, highlights the need for multidisciplinary approaches to understand the epidemiology and drivers of antimicrobial resistance in low-income countries.}, language = {en} } @article{BauerConchaMendozaKreienbrocketal.2022, author = {Bauer, Hannah and Concha Mendoza, Gustavo Andr{\´e}s and Kreienbrock, Lothar and Hartmann, Maria and Frickmann, Hagen and Kann, Simone}, title = {Prevalence of common diseases in Indigenous people in Colombia}, series = {Tropical Medicine and Infectious Disease}, volume = {7}, journal = {Tropical Medicine and Infectious Disease}, number = {6}, issn = {2414-6366}, doi = {10.3390/tropicalmed7060109}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-278953}, year = {2022}, abstract = {The Indigenous tribe called the Wiwa lives retracted in the Sierra Nevada de Santa Marta, Colombia. Little is known about their health status and whether the health care system in place covers their needs. In 2017 and 2018, a permanent physician was in charge for the Wiwa. Diseases and complaints were registered, ranked, and classified with the ICD-10 coding. Datasets from the Indigenous health care provider Dusakawi, collected from local health points and health brigades travelling sporadically into the fields for short visits, were compared. Furthermore, a list of provided medication was evaluated regarding the recorded needs. The most common complaints found were respiratory, infectious and parasitic, and digestive diseases. The top ten diagnoses collected in the health points and in the health brigade datasets were similar, although with a different ranking. The available medication showed a basic coverage only, with a critical lack of treatment for many severe, chronic, and life-threatening diseases. Most of the detected diseases in the Indigenous population are avoidable by an improvement in health care access, an expansion of the provided medication, and an increase in knowledge, hygiene, and life standards.}, language = {en} } @article{StrobelSickenbergerSchoenetal.2022, author = {Strobel, Katharina and Sickenberger, Christina and Schoen, Christoph and Kneitz, Hermann and Kolb-M{\"a}urer, Annette and Goebeler, Matthias}, title = {Diagnosis and therapy of Mycobacterium marinum: a single-center 21-year retrospective analysis}, series = {Journal der Deutschen Dermatologischen Gesellschaft}, volume = {20}, journal = {Journal der Deutschen Dermatologischen Gesellschaft}, number = {9}, doi = {10.1111/ddg.14847}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-318428}, pages = {1211 -- 1218}, year = {2022}, abstract = {Background and Objectives In Europe, infections with Mycobacterium (M.) marinum are rare. We conducted a retrospective single-center study to assess the clinical spectrum of M. marinum infection and its diagnosis, treatment and outcome under real-world conditions. Patients and Methods Eighteen patients presenting with M. marinum infections between 1998 and 2018 were identified in the data warehouse of the University Hospital W{\"u}rzburg and considered for detailed analysis. Results Twelve patients reported aquatic exposure. In 16/18 cases the upper extremities were affected. No invasive infections were detected. Mean time to diagnosis was 15 weeks. Histology revealed granulomatous inflammation in 14 patients while mycobacterial cultures were positive for M. marinum in 16 cases. Most patients received antibiotic monotherapy (14/18) while combination therapy was administered in four cases. Treatment (with a median duration of 10 weeks) was successful in 13 patients. Five patients were lost to follow-up. Conclusions Our retrospective analysis of M. marinum infections at a German tertiary referral center revealed a considerable diagnostic delay and the relevance of microbiological culture, PCR and histology for diagnosis. Monotherapy with clarithromycin (rather than doxycycline) appeared as a reasonable treatment option while immunosuppressed or -compromised patients and those with extended disease received combination therapy.}, language = {en} } @article{NieuwenhuizenEvans2022, author = {Nieuwenhuizen, Natalie E. and Evans, Joanna C.}, title = {Cellular and molecular mechanisms in mycobacterial infection}, series = {International Journal of Molecular Sciences}, volume = {23}, journal = {International Journal of Molecular Sciences}, number = {13}, issn = {1422-0067}, doi = {10.3390/ijms23137205}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-284370}, year = {2022}, abstract = {No abstract available}, language = {en} } @article{StreckForstervonHertzbergBoelchetal.2022, author = {Streck, Laura Elisa and Forster, Johannes and von Hertzberg-Boelch, Sebastian Philipp and Reichel, Thomas and Rudert, Maximilian and Rueckl, Kilian}, title = {The role of synovial fluid aspiration in shoulder joint infections}, series = {BMC Musculoskeletal Disorders}, volume = {23}, journal = {BMC Musculoskeletal Disorders}, doi = {10.1186/s12891-022-05285-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300795}, year = {2022}, abstract = {Background Joint aspiration with analysis of synovial fluid white blood cell count (WBC) and microbiological culture is a widely established aspect in the diagnosis of shoulder joint infections (SJI). In case of a two stage revision for SJI, joint aspiration before re-/implantation of a total shoulder arthroplasty (TSA) was used to rule out persistent infection for years but its value is under debate. Shoulder specific data on all aspects is rare. The current study aims to answer the following research questions: Does joint aspiration have an insufficient predictive value in the diagnosis of SJI in (1) initial workup and (2) before definite arthroplasty with polymethylmethacrylate (PMMA)-Spacer in place? Methods This retrospective evaluation investigates 35 patients that were treated for SJI with a two staged implantation of a TSA after debridement and implantation of an PMMA-Spacer. Joint aspirations were performed preoperatively (PA) and before re-/implantation of the prosthesis while spacer was in place (interstage aspiration, IA). Samples were taken for microbiological culture and analysis of WBC. Sensitivity and specificity were calculated with reference to intraoperative microbiological samples. Receiver Operating Characteristic (ROC), Area-Under-Curve analysis (AUC) and calculation of the Youden index were performed to find optimum cut-off for WBC. Results The sensitivity of microbiological cultures from PA was 58.3\% and the specificity was 88.9\%. The mean WBC was 27,800 leucocytes/mm3 (range 400-96,300). The maximum Youden index (0.857) was a cut-off of 2600 leucocytes/mm3 with a sensitivity of 85.7\% and a specificity of 100.0\%. The sensitivity and specificity of IA were 0.0\% and 88.5\%, respectively. Conclusions Preoperative aspiration is likely to miss Cutibacteria spp. and CoNS and cannot rule out infection for sure. However, we recommend it for its advantages of targeted antibiotic therapy in case of germ identification. Empiric antibiotic therapy should cover Cutibacteria and CoNS even if aspiration showed negative microbiological cultures. In contrast, the diagnostic value of interstage aspiration does not qualify for its routine use.}, language = {en} } @phdthesis{Schlag2017, author = {Schlag, Stephanie}, title = {Mikrobiologie, Klinik und Antibiotika-Therapie invasiver bakterieller Infektionen an der W{\"u}rzburger Universit{\"a}ts-Kinderklinik zwischen 2006 und 2012}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-156236}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2017}, abstract = {In einem Zeitraum von sieben Jahren untersuchten wir invasive bakterielle Infektionen bei Kindern durch die wichtigsten Erreger von Blutstrombahninfektionen an der W{\"u}rzburger Universit{\"a}ts-Kinderklinik.}, subject = {Antibiotikum}, language = {de} } @article{StockPetrašMelteretal.2016, author = {Stock, Nina Katharina and Petr{\´a}š, Petr and Melter, Oto and Kapounov{\´a}, Gabriela and Vopalkov{\´a}, Petra and Kubele, Jan and Vaniš, V{\´a}clav and Tkadlec, Jan and Buk{\´a}čkov{\´a}, Eva and Machov{\´a}, Ivana and Jindr{\´a}k, Vlastimil}, title = {Importance of Multifaceted Approaches in Infection Control: A Practical Experience from an Outbreak Investigation}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {6}, doi = {10.1371/journal.pone.0157981}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166891}, pages = {e0157981}, year = {2016}, abstract = {Background This study presents the results of a multidisciplinary, nosocomial MRSA outbreak investigation in an 8-bed medical intensive care unit (ICU). The identification of seven MRSA positive patients in the beginning of 2014 led to the closure of the ward for several weeks. A multidisciplinary, retrospective investigation was initiated in order to identify the reason and the source for the outbreak, describe MRSA transmission in the department and identify limitations in infection control. Methods The investigation comprised an epidemiological description of MRSA cases from 2012 to 2014 and a characterization of MRSA isolates, including phage-, spa- and PFGE-typing. Additionally, MRSA screening was performed from the hospital staff and the environment. To identify the reason for the outbreak, work-related, psychological and behavioral factors were investigated by impartial audits and staff interviews. Results Thirty-one MRSA cases were registered during the study period, and 36 isolates were investigated. Molecular typing determined the outbreak strain (phage type 54/812, PFGE type A4, spa type t003) and identified the probable index case. Nasal carriage in one employee and a high environmental contamination with the outbreak strain was documented. Important gaps in nursing procedures and general management were identified. Elevated stress levels and communication problems preceded the outbreak. Compliance with hand hygiene and isolation procedures was evaluated as appropriate. Conclusion This study demonstrates the complexity of controlling hospital-associated infections. The combined use of different typing methods is beneficial for outbreak investigations. Psychological, behavioral and other work-related factors have an important impact on the spread of nosocomial pathogens. These factors should be addressed and integrated in routine infection control practice.}, language = {en} } @article{PetersFohmannRudeletal.2021, author = {Peters, Simon and Fohmann, Ingo and Rudel, Thomas and Schubert-Unkmeir, Alexandra}, title = {A Comprehensive Review on the Interplay between Neisseria spp. and Host Sphingolipid Metabolites}, series = {Cells}, volume = {10}, journal = {Cells}, number = {11}, issn = {2073-4409}, doi = {10.3390/cells10113201}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250203}, year = {2021}, abstract = {Sphingolipids represent a class of structural related lipids involved in membrane biology and various cellular processes including cell growth, apoptosis, inflammation and migration. Over the past decade, sphingolipids have become the focus of intensive studies regarding their involvement in infectious diseases. Pathogens can manipulate the sphingolipid metabolism resulting in cell membrane reorganization and receptor recruitment to facilitate their entry. They may recruit specific host sphingolipid metabolites to establish a favorable niche for intracellular survival and proliferation. In contrast, some sphingolipid metabolites can also act as a first line defense against bacteria based on their antimicrobial activity. In this review, we will focus on the strategies employed by pathogenic Neisseria spp. to modulate the sphingolipid metabolism and hijack the sphingolipid balance in the host to promote cellular colonization, invasion and intracellular survival. Novel techniques and innovative approaches will be highlighted that allow imaging of sphingolipid derivatives in the host cell as well as in the pathogen.}, language = {en} } @article{ApsemidouFuellerIdelevichetal.2020, author = {Apsemidou, Athanasia and F{\"u}ller, Miriam Antonie and Idelevich, Evgeny A. and Kurzai, Oliver and Tragiannidis, Athanasios and Groll, Andreas H.}, title = {Candida lusitaniae breakthrough fungemia in an immuno-compromised adolescent: case report and review of the literature}, series = {Journal of Fungi}, volume = {6}, journal = {Journal of Fungi}, number = {4}, issn = {2309-608X}, doi = {10.3390/jof6040380}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-220125}, year = {2020}, abstract = {Candida lusitaniae is a rare cause of candidemia that is known for its unique capability to rapidly acquire resistance to amphotericin B. We report the case of an adolescent with grade IV graft-vs.-host disease after hematopoietic cell transplantation who developed catheter-associated C. lusitaniae candidemia while on therapeutic doses of liposomal amphotericin B. We review the epidemiology of C. lusitaniae bloodstream infections in adult and pediatric patients, the development of resistance, and its role in breakthrough candidemia. Appropriate species identification, in vitro susceptibility testing, and source control are pivotal to optimal management of C. lusitaniae candidemia. Initial antifungal therapy may consist of an echinocandin and be guided by in vitro susceptibility and clinical response.}, language = {en} } @article{KochHellenbrandSchinketal.2016, author = {Koch, J. and Hellenbrand, W. and Schink, S. and Wichmann, O. and Carganico, A. and Drewes, J. and Kruspe, M. and Suckau, M. and Claus, H. and Marcus, U.}, title = {Evaluation of a temporary vaccination recommendation in response to an outbreak of invasive meningococcal serogroup C disease in men who have sex with men in Berlin, 2013-2014}, series = {Eurosurveillance}, volume = {21}, journal = {Eurosurveillance}, number = {5}, doi = {10.2807/1560-7917.ES.2016.21.5.30122}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-165070}, pages = {pii=30122}, year = {2016}, abstract = {Meningococcal serogroup C (MenC) vaccination of men who have sex with men (MSM) was temporarily recommended to control an outbreak of invasive MenC disease among MSM in Berlin in 2012-2013. Vaccination was offered to HIV-infected MSM free of charge; others had to request reimbursement or pay out of pocket. We aimed to assess (i) awareness and acceptance of this recommendation through an online survey of MSM, (ii) implementation through a survey of primary care physicians and analysis of vaccine prescriptions, and (iii) impact through analysis of notified cases. Among online survey respondents, 60\% were aware of the recommendation. Of these, 39\% had obtained vaccination (70\% of HIV-infected, 13\% of HIV-negative/non-tested MSM). Awareness of recommendation and vaccination were positively associated with HIV infection, primary care physicians' awareness of respondents' sexual orientation, and exposure to multiple information sources. Most (26/30) physicians informed clients about the recommendation. Physicians considered concerns regarding reimbursement, vaccine safety and lack of perceived disease risk as primary barriers. After the recommendation, no further outbreak-related cases occurred. To reach and motivate target groups, communication of a new outbreak-related vaccination recommendation should address potential concerns through as many information channels as possible and direct reimbursement of costs should be enabled.}, language = {en} } @article{WeissSchlegelTerpitzetal.2020, author = {Weiss, Esther and Schlegel, Jan and Terpitz, Ulrich and Weber, Michael and Linde, J{\"o}rg and Schmitt, Anna-Lena and H{\"u}nniger, Kerstin and Marischen, Lothar and Gamon, Florian and Bauer, Joachim and L{\"o}ffler, Claudia and Kurzai, Oliver and Morton, Charles Oliver and Sauer, Markus and Einsele, Hermann and Loeffler, Juergen}, title = {Reconstituting NK Cells After Allogeneic Stem Cell Transplantation Show Impaired Response to the Fungal Pathogen Aspergillus fumigatus}, series = {Frontiers in Immunology}, volume = {11}, journal = {Frontiers in Immunology}, issn = {1664-3224}, doi = {10.3389/fimmu.2020.02117}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-212581}, year = {2020}, abstract = {Delayed natural killer (NK) cell reconstitution after allogeneic stem cell transplantation (alloSCT) is associated with a higher risk of developing invasive aspergillosis. The interaction of NK cells with the human pathogen Aspergillus (A.) fumigatus is mediated by the fungal recognition receptor CD56, which is relocated to the fungal interface after contact. Blocking of CD56 signaling inhibits the fungal mediated chemokine secretion of MIP-1α, MIP-1β, and RANTES and reduces cell activation, indicating a functional role of CD56 in fungal recognition. We collected peripheral blood from recipients of an allograft at defined time points after alloSCT (day 60, 90, 120, 180). NK cells were isolated, directly challenged with live A. fumigatus germ tubes, and cell function was analyzed and compared to healthy age and gender-matched individuals. After alloSCT, NK cells displayed a higher percentage of CD56\(^{bright}\)CD16\(^{dim}\) cells throughout the time of blood collection. However, CD56 binding and relocalization to the fungal contact side were decreased. We were able to correlate this deficiency to the administration of corticosteroid therapy that further negatively influenced the secretion of MIP-1α, MIP-1β, and RANTES. As a consequence, the treatment of healthy NK cells ex vivo with corticosteroids abrogated chemokine secretion measured by multiplex immunoassay. Furthermore, we analyzed NK cells regarding their actin cytoskeleton by Structured Illumination Microscopy (SIM) and flow cytometry and demonstrate an actin dysfunction of NK cells shown by reduced F-actin content after fungal co-cultivation early after alloSCT. This dysfunction remains until 180 days post-alloSCT, concluding that further actin-dependent cellular processes may be negatively influenced after alloSCT. To investigate the molecular pathomechansism, we compared CD56 receptor mobility on the plasma membrane of healthy and alloSCT primary NK cells by single-molecule tracking. The results were very robust and reproducible between tested conditions which point to a different molecular mechanism and emphasize the importance of proper CD56 mobility.}, language = {en} } @article{NyawaleMoremiMohamedetal.2022, author = {Nyawale, Helmut A. and Moremi, Nyambura and Mohamed, Mohamed and Njwalila, Johnson and Silago, Vitus and Krone, Manuel and Konje, Eveline T. and Mirambo, Mariam M. and Mshana, Stephen E.}, title = {High seroprevalence of SARS-CoV-2 in Mwanza, northwestern Tanzania: a population-based survey}, series = {International Journal of Environmental Research and Public Health}, volume = {19}, journal = {International Journal of Environmental Research and Public Health}, number = {18}, issn = {1660-4601}, doi = {10.3390/ijerph191811664}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-288134}, year = {2022}, abstract = {The transmission of the SARS-CoV-2 virus, which causes COVID-19, has been documented worldwide. However, the evidence of the extent to which transmission has occurred in different countries is still to be established. Understanding the magnitude and distribution of SARS-CoV-2 through seroprevalence studies is important in designing control and preventive strategies in communities. This study investigated the seropositivity of the SARS-CoV-2 virus antibodies in the communities of three different districts in the Mwanza region, Tanzania. A household cross-sectional survey was conducted in September 2021 using the modified African Centre for Disease and Prevention (ACDC) survey protocol. A blood sample was obtained from one member of each of the selected households who consented to take part in the survey. Immunochromatographic rapid test kits were used to detect IgM and IgG SARS-CoV-2 antibodies, followed by descriptive data analysis. Overall, 805 participants were enrolled in the study with a median age of 35 (interquartile range (IQR):27-47) years. The overall SARS-CoV-2 seropositivity was 50.4\% (95\%CI: 46.9-53.8\%). The IgG and IgM seropositivity of the SARS-CoV-2 antibodies was 49.3\% and 7.2\%, respectively, with 6.1\% being both IgG and IgM seropositive. A history of runny nose (aOR: 1.84, 95\%CI: 1.03-3.5, p = 0.036), loss of taste (aOR: 1.84, 95\%CI: 1.12-4.48, p = 0.023), and living in Ukerewe (aOR: 3.55, 95\%CI: 1.68-7.47, p = 0.001) and Magu (aOR: 2.89, 95\%CI: 1.34-6.25, p= 0.007) were all independently associated with SARS-CoV-2 IgM seropositivity. Out of the studied factors, living in the Ukerewe district was independently associated with IgG seropositivity (aOR 1.29, CI 1.08-1.54, p = 0.004). Twenty months after the first case of COVID-19 in Tanzania, about half of the studied population in Mwanza was seropositive for SARS-CoV-2.}, language = {en} } @article{StraubStapfFischeretal.2022, author = {Straub, Anton and Stapf, Maximilian and Fischer, Markus and Vollmer, Andreas and Linz, Christian and L{\^a}m, Thi{\^e}n-Tr{\´i} and K{\"u}bler, Alexander and Brands, Roman C. and Scherf-Clavel, Oliver and Hartmann, Stefan}, title = {Bone concentration of ampicillin/sulbactam: a pilot study in patients with osteonecrosis of the jaw}, series = {International Journal of Environmental Research and Public Health}, volume = {19}, journal = {International Journal of Environmental Research and Public Health}, number = {22}, issn = {1660-4601}, doi = {10.3390/ijerph192214917}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-297413}, year = {2022}, abstract = {Osteonecrosis of the jaw (ONJ) occurs typically after irradiation of the head and neck area or after the intake of antiresorptive agents. Both interventions can lead to compromised bone perfusion and can ultimately result in infection and necrosis. Treatment usually consists of surgical necrosectomy and prolonged antibiotic therapy, usually through beta-lactams such as ampicillin/sulbactam. The poor blood supply in particular raises the question as to whether this form of antibiosis can achieve sufficient concentrations in the bone. Therefore, we investigated the antibiotic concentration in plasma and bone samples in a prospective study. Bone samples were collected from the necrosis core and in the vital surrounding bone. The measured concentrations in plasma for ampicillin and sulbactam were 126.3 ± 77.6 and 60.2 ± 35.0 µg/mL, respectively. In vital bone and necrotic bone samples, the ampicillin/sulbactam concentrations were 6.3 ± 7.8/1.8 ± 2.0 µg/g and 4.9 ± 7.0/1.7 ± 1.7 µg/g, respectively. These concentrations are substantially lower than described in the literature. However, the concentration seems sufficient to kill most bacteria, such as Streptococci and Staphylococci, which are mostly present in the biofilm of ONJ. We, therefore, conclude that intravenous administration of ampicillin/sulbactam remains a valuable treatment in the therapy of ONJ. Nevertheless, increasing resistance of Escherichia coli towards beta-lactam antibiotics have been reported and should be considered.}, language = {en} } @article{SilwedelHaarmannFehrholzetal.2019, author = {Silwedel, Christine and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Speer, Christian P. and Glaser, Kirsten}, title = {More than just inflammation: Ureaplasma species induce apoptosis in human brain microvascular endothelial cells}, series = {Journal of Neuroinflammation}, volume = {16}, journal = {Journal of Neuroinflammation}, doi = {10.1186/s12974-019-1413-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200711}, pages = {38}, year = {2019}, abstract = {Background Ureaplasma species (spp.) are commonly regarded as low-virulent commensals but may cause invasive diseases in immunocompromised adults and in neonates, including neonatal meningitis. The interactions of Ureaplasma spp. with host defense mechanisms are poorly understood. This study addressed Ureaplasma-driven cell death, concentrating on apoptosis as well as inflammatory cell death. Methods Human brain microvascular endothelial cells (HBMEC) were exposed to Ureaplasma (U.) urealyticum serovar 8 (Uu8) and U. parvum serovar 3 (Up3). Resulting numbers of dead cells as well as mRNA levels and enzyme activity of key agents in programmed cell death were assessed by flow cytometry, RNA sequencing, and qRT-PCR, respectively. xCELLigence data were used for real-time monitoring of changes in cell adhesion properties. Results Both Ureaplasma isolates induced cell death (p < 0.05, vs. broth). Furthermore, Ureaplasma spp. enhanced mRNA levels for genes in apoptosis, including caspase 3 (Up3 p < 0.05, vs. broth), caspase 7 (p < 0.01), and caspase 9 (Up3 p < 0.01). Caspase 3 activity was increased upon Uu8 exposure (p < 0.01). Vice versa, Ureaplasma isolates downregulated mRNA levels for proteins involved in inflammatory cell death, namely caspase 1 (Uu8 p < 0.01, Up3 p < 0.001), caspase 4 (Uu8 p < 0.05, Up3 p < 0.01), NOD-like receptor pyrin domain-containing 3 (Uu8 p < 0.05), and receptor-interacting protein kinase 3 (p < 0.05). Conclusions By inducing apoptosis in HBMEC as main constituents of the blood-brain barrier, Ureaplasma spp. may provoke barrier breakdown. Simultaneous suppression of inflammatory cell death may additionally attenuate host defense strategies. Ultimate consequence could be invasive and long-term CNS infections by Ureaplasma spp.}, language = {en} } @article{ZoranSeelbinderWhiteetal.2022, author = {Zoran, Tamara and Seelbinder, Bastian and White, Philip Lewis and Price, Jessica Sarah and Kraus, Sabrina and Kurzai, Oliver and Linde, Joerg and H{\"a}der, Antje and Loeffler, Claudia and Grigoleit, Goetz Ulrich and Einsele, Hermann and Panagiotou, Gianni and Loeffler, Juergen and Sch{\"a}uble, Sascha}, title = {Molecular profiling reveals characteristic and decisive signatures in patients after allogeneic stem cell transplantation suffering from invasive pulmonary aspergillosis}, series = {Journal of Fungi}, volume = {8}, journal = {Journal of Fungi}, number = {2}, issn = {2309-608X}, doi = {10.3390/jof8020171}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-262105}, year = {2022}, abstract = {Despite available diagnostic tests and recent advances, diagnosis of pulmonary invasive aspergillosis (IPA) remains challenging. We performed a longitudinal case-control pilot study to identify host-specific, novel, and immune-relevant molecular candidates indicating IPA in patients post allogeneic stem cell transplantation (alloSCT). Supported by differential gene expression analysis of six relevant in vitro studies, we conducted RNA sequencing of three alloSCT patients categorized as probable IPA cases and their matched controls without Aspergillus infection (66 samples in total). We additionally performed immunoassay analysis for all patient samples to gain a multi-omics perspective. Profiling analysis suggested LGALS2, MMP1, IL-8, and caspase-3 as potential host molecular candidates indicating IPA in investigated alloSCT patients. MMP1, IL-8, and caspase-3 were evaluated further in alloSCT patients for their potential to differentiate possible IPA cases and patients suffering from COVID-19-associated pulmonary aspergillosis (CAPA) and appropriate control patients. Possible IPA cases showed differences in IL-8 and caspase-3 serum levels compared with matched controls. Furthermore, we observed significant differences in IL-8 and caspase-3 levels among CAPA patients compared with control patients. With our conceptual work, we demonstrate the potential value of considering the human immune response during Aspergillus infection to identify immune-relevant molecular candidates indicating IPA in alloSCT patients. These human host candidates together with already established fungal biomarkers might improve the accuracy of IPA diagnostic tools.}, language = {en} } @article{WaltherWagnerKurzai2019, author = {Walther, Grit and Wagner, Lysett and Kurzai, Oliver}, title = {Updates on the taxonomy of Mucorales with an emphasis on clinically important taxa}, series = {Journal of Fungi}, volume = {5}, journal = {Journal of Fungi}, number = {4}, issn = {2309-608X}, doi = {10.3390/jof5040106}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-193081}, year = {2019}, abstract = {Fungi of the order Mucorales colonize all kinds of wet, organic materials and represent a permanent part of the human environment. They are economically important as fermenting agents of soybean products and producers of enzymes, but also as plant parasites and spoilage organisms. Several taxa cause life-threatening infections, predominantly in patients with impaired immunity. The order Mucorales has now been assigned to the phylum Mucoromycota and is comprised of 261 species in 55 genera. Of these accepted species, 38 have been reported to cause infections in humans, as a clinical entity known as mucormycosis. Due to molecular phylogenetic studies, the taxonomy of the order has changed widely during the last years. Characteristics such as homothallism, the shape of the suspensors, or the formation of sporangiola are shown to be not taxonomically relevant. Several genera including Absidia, Backusella, Circinella, Mucor, and Rhizomucor have been amended and their revisions are summarized in this review. Medically important species that have been affected by recent changes include Lichtheimia corymbifera, Mucor circinelloides, and Rhizopus microsporus. The species concept of Rhizopus arrhizus (syn. R. oryzae) is still a matter of debate. Currently, species identification of the Mucorales is best performed by sequencing of the internal transcribed spacer (ITS) region. Ecologically, the Mucorales represent a diverse group but for the majority of taxa, the ecological role and the geographic distribution remain unknown. Understanding the biology of these opportunistic fungal pathogens is a prerequisite for the prevention of infections, and, consequently, studies on the ecology of the Mucorales are urgently needed.}, language = {en} } @article{AmpattuHagmannLiangetal.2017, author = {Ampattu, Biju Joseph and Hagmann, Laura and Liang, Chunguang and Dittrich, Marcus and Schl{\"u}ter, Andreas and Blom, Jochen and Krol, Elizaveta and Goesmann, Alexander and Becker, Anke and Dandekar, Thomas and M{\"u}ller, Tobias and Schoen, Christoph}, title = {Transcriptomic buffering of cryptic genetic variation contributes to meningococcal virulence}, series = {BMC Genomics}, volume = {18}, journal = {BMC Genomics}, number = {282}, doi = {10.1186/s12864-017-3616-7}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157534}, year = {2017}, abstract = {Background: Commensal bacteria like Neisseria meningitidis sometimes cause serious disease. However, genomic comparison of hyperinvasive and apathogenic lineages did not reveal unambiguous hints towards indispensable virulence factors. Here, in a systems biological approach we compared gene expression of the invasive strain MC58 and the carriage strain α522 under different ex vivo conditions mimicking commensal and virulence compartments to assess the strain-specific impact of gene regulation on meningococcal virulence. Results: Despite indistinguishable ex vivo phenotypes, both strains differed in the expression of over 500 genes under infection mimicking conditions. These differences comprised in particular metabolic and information processing genes as well as genes known to be involved in host-damage such as the nitrite reductase and numerous LOS biosynthesis genes. A model based analysis of the transcriptomic differences in human blood suggested ensuing metabolic flux differences in energy, glutamine and cysteine metabolic pathways along with differences in the activation of the stringent response in both strains. In support of the computational findings, experimental analyses revealed differences in cysteine and glutamine auxotrophy in both strains as well as a strain and condition dependent essentiality of the (p)ppGpp synthetase gene relA and of a short non-coding AT-rich repeat element in its promoter region. Conclusions: Our data suggest that meningococcal virulence is linked to transcriptional buffering of cryptic genetic variation in metabolic genes including global stress responses. They further highlight the role of regulatory elements for bacterial virulence and the limitations of model strain approaches when studying such genetically diverse species as N. meningitidis.}, language = {en} } @article{KlughammerDittrichBlometal.2017, author = {Klughammer, Johanna and Dittrich, Marcus and Blom, Jochen and Mitesser, Vera and Vogel, Ulrich and Frosch, Matthias and Goesmann, Alexander and M{\"u}ller, Tobias and Schoen, Christoph}, title = {Comparative genome sequencing reveals within-host genetic changes in Neisseria meningitidis during invasive disease}, series = {PLoS ONE}, volume = {12}, journal = {PLoS ONE}, number = {1}, doi = {10.1371/journal.pone.0169892}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-159547}, pages = {e0169892}, year = {2017}, abstract = {Some members of the physiological human microbiome occasionally cause life-threatening disease even in immunocompetent individuals. A prime example of such a commensal pathogen is Neisseria meningitidis, which normally resides in the human nasopharynx but is also a leading cause of sepsis and epidemic meningitis. Using N. meningitidis as model organism, we tested the hypothesis that virulence of commensal pathogens is a consequence of within host evolution and selection of invasive variants due to mutations at contingency genes, a mechanism called phase variation. In line with the hypothesis that phase variation evolved as an adaptation to colonize diverse hosts, computational comparisons of all 27 to date completely sequenced and annotated meningococcal genomes retrieved from public databases showed that contingency genes are indeed enriched for genes involved in host interactions. To assess within-host genetic changes in meningococci, we further used ultra-deep whole-genome sequencing of throat-blood strain pairs isolated from four patients suffering from invasive meningococcal disease. We detected up to three mutations per strain pair, affecting predominantly contingency genes involved in type IV pilus biogenesis. However, there was not a single (set) of mutation(s) that could invariably be found in all four pairs of strains. Phenotypic assays further showed that these genetic changes were generally not associated with increased serum resistance, higher fitness in human blood ex vivo or differences in the interaction with human epithelial and endothelial cells in vitro. In conclusion, we hypothesize that virulence of meningococci results from accidental emergence of invasive variants during carriage and without within host evolution of invasive phenotypes during disease progression in vivo.}, language = {en} } @article{DichtlForsterOrmannsetal.2020, author = {Dichtl, Karl and Forster, Johannes and Ormanns, Steffen and Horns, Heidi and Suerbaum, Sebastian and Seybold, Ulrich and Wagener, Johannes}, title = {Comparison of β-D-Glucan and galactomannan in serum for detection of invasive aspergillosis: retrospective analysis with focus on early diagnosis}, series = {Journal of Fungi}, volume = {6}, journal = {Journal of Fungi}, number = {4}, issn = {2309-608X}, doi = {10.3390/jof6040253}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-216298}, year = {2020}, abstract = {The early diagnosis of invasive aspergillosis (IA) relies mainly on computed tomography imaging and testing for fungal biomarkers such as galactomannan (GM). We compared an established ELISA for the detection of GM with a turbidimetric assay for detection of the panfungal biomarker β-D-glucan (BDG) for early diagnosis of IA. A total of 226 serum specimens from 47 proven and seven probable IA cases were analysed. Sensitivity was calculated for samples obtained closest to the day of IA-diagnosis (d0). Additional analyses were performed by including samples obtained during the presumed course of disease. Most IA cases involved the respiratory system (63\%), and Aspergillus fumigatus was the most frequently isolated species (59\%). For proven cases, sensitivity of BDG/GM analysis was 57\%/40\%. Including all samples dating from -6 to +1 weeks from d0 increased sensitivities to 74\%/51\%. Sensitivity of BDG testing was as high as or higher than GM testing for all subgroups and time intervals analysed. BDG testing was less specific (90-93\%) than GM testing (99-100\%). Combining BDG and GM testing resulted in sensitivity/specificity of 70\%/91\%. Often, BDG testing was positive before GM testing. Our study backs the use of BDG for diagnosis of suspected IA. We suggest combining BDG and GM to improve the overall sensitivity.}, language = {en} } @article{SattlerNosterBrunkeetal.2021, author = {Sattler, Janko and Noster, Janina and Brunke, Anne and Plum, Georg and Wiegel, Pia and Kurzai, Oliver and Meis, Jacques F. and Hamprecht, Axel}, title = {Comparison of two commercially available qPCR kits for the detection of Candida auris}, series = {Journal of Fungi}, volume = {7}, journal = {Journal of Fungi}, number = {2}, issn = {2309-608X}, doi = {10.3390/jof7020154}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-228879}, year = {2021}, abstract = {Candida auris is an emerging pathogen with resistance to many commonly used antifungal agents. Infections with C. auris require rapid and reliable detection methods to initiate successful medical treatment and contain hospital outbreaks. Conventional identification methods are prone to errors and can lead to misidentifications. PCR-based assays, in turn, can provide reliable results with low turnaround times. However, only limited data are available on the performance of commercially available assays for C. auris detection. In the present study, the two commercially available PCR assays AurisID (OLM, Newcastle Upon Tyne, UK) and Fungiplex Candida Auris RUO Real-Time PCR (Bruker, Bremen, Germany) were challenged with 29 C. auris isolates from all five clades and eight other Candida species as controls. AurisID reliably detected C. auris with a limit of detection (LoD) of 1 genome copies/reaction. However, false positive results were obtained with high DNA amounts of the closely related species C. haemulonii, C. duobushaemulonii and C. pseudohaemulonii. The Fungiplex Candida Auris RUO Real-Time PCR kit detected C. auris with an LoD of 9 copies/reaction. No false positive results were obtained with this assay. In addition, C. auris could also be detected in human blood samples spiked with pure fungal cultures by both kits. In summary, both kits could detect C. auris-DNA at low DNA concentrations but differed slightly in their limits of detection and specificity.}, language = {en} } @phdthesis{vonPapen2019, author = {von Papen, Hans Michael}, title = {Untersuchungen zum Einfluss der Meningokokkeninfektion auf den Zellzyklus von Epithelzellen}, doi = {10.25972/OPUS-19286}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-192862}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2019}, abstract = {Zahlreiche humanpathogene bakterielle Erreger k{\"o}nnen ihre F{\"a}higkeit zur Kolonisation epithelialer Barrieren optimieren, indem sie mit dem Zellzyklus der infizierten Wirtszelle in Wechselwirkung treten und so die Abschilferung und Erneuerung des Epithels verz{\"o}gern. Die hierbei wirksamen bakteriellen Effektoren sind als „Cyclomoduline" bekannt und gelten als neue Klasse bakterieller Pathogenit{\"a}tsfaktoren. Ziel der vorliegenden Promotionsarbeit war es zu untersuchen, ob durch die Infektion menschlicher pharyngealer Epithelzellen mit N. meningitidis der Zellzyklus der Wirtszelle beeinflusst wird. Mit zwei verschiedenen Untersuchungsmethoden konnte {\"u}bereinstimmend gezeigt werden, dass die Infektion der Epithelzelllinie Detroit 562 mit verschiedenen Meningokokkenisolaten zu einer signifikanten Akkumulation von Epithelzellen in der G1-Phase f{\"u}hrte. Dieser Effekt wurde sowohl von pathogenen Meningokokkenst{\"a}mmen als auch von Tr{\"a}gerst{\"a}mmen ausgel{\"o}st, jedoch nur durch Isolate, die f{\"a}hig zur Adh{\"a}renz und zur Invasion in die Epithelzelle waren. Durch Hitzebehandlung der Bakterien konnte der Zellzyklusarrest vollst{\"a}ndig aufgehoben werden. Ebenso konnte der Effekt durch Inkubation der Epithelzellen mit bakteriellen Kultur{\"u}berst{\"a}nden und durch Infektion der Zellen mit E. coli-St{\"a}mmen, welche die Meningokokkenadh{\"a}sine Opa und Opc {\"u}berexprimieren, nicht ausgel{\"o}st werden. Es konnte weiterhin nachgewiesen werden, dass die Infektion mit N. meningitidis in der Zielzelle zu einer signifikant gesteigerten Expression des CDK-Inhibitors p21WAF1/Cip1 f{\"u}hrte, begleitet von einer vermehrten Lokalisation im Zellkern. Auch zeigte sich eine ver{\"a}nderte Proteinexpression der f{\"u}r die G1-Phase relevanten Cycline D und E. Diese scheint sich erst posttranslational zu ereignen, da die unterschiedliche Expression auf mRNA-Ebene nicht festgestellt werden konnte. Zusammenfassend konnte dargestellt werden, dass die Infektion von Pharynxepithelzellen mit lebenden, zur Adh{\"a}renz und Invasion f{\"a}higen Meningokokkenst{\"a}mmen in der menschlichen Zielzelle einen Zellzyklusarrest in der G1-Phase verursacht, vermutlich durch ver{\"a}nderte Expression der Zellzyklusregulatoren p21WAF1/Cip1, Cyclin D und Cyclin E. M{\"o}glicherweise stellt die Induktion dieses Zellzyklusarrestes einen wichtigen Schritt in der Pathogenese der bakteriellen Kolonisation des oberen Atemwegsepithels durch N. meningitidis dar.}, subject = {Neisseria meningitidis}, language = {de} } @article{StreckGaalForsteretal.2021, author = {Streck, Laura Elisa and Gaal, Chiara and Forster, Johannes and Konrads, Christian and Hertzberg-Boelch, Sebastian Philipp von and Rueckl, Kilian}, title = {Defining a synovial fluid white blood cell count threshold to predict periprosthetic infection after shoulder arthroplasty}, series = {Journal of Clinical Medicine}, volume = {11}, journal = {Journal of Clinical Medicine}, number = {1}, issn = {2077-0383}, doi = {10.3390/jcm11010050}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-252275}, year = {2021}, abstract = {Background: The diagnosis of periprosthetic shoulder infection (PSI) requires a thorough diagnostic workup. Synovial fluid aspiration has been proven to be a reliable tool in the diagnosis of joint infections of the lower extremity, but shoulder specific data is limited. This study defines a threshold for synovial fluid white blood cell count (WBC) and assesses the reliability of microbiological cultures. Methods: Retrospective study of preoperative and intraoperative fluid aspiration of 31 patients who underwent a revision of a shoulder arthroplasty (15 with PSI defined by IDSA criteria, 16 without infection). The threshold for WBC was calculated by ROC/AUC analysis. Results: WBC was significantly higher in patients with PSI than in other patients. A threshold of 2800 leucocytes/mm\(^3\) showed a sensitivity of 87\% and a specificity of 88\% (AUROC 0.92). Microbiological cultures showed a sensitivity of 76\% and a specificity of 100\%. Conclusions: A threshold of 2800 leucocytes/mm\(^3\) in synovial fluid can be recommended to predict PSI. Microbiological culture has an excellent specificity and allows for targeted antibiotic therapy. Joint aspiration presents an important pillar to diagnose PSI.}, language = {en} } @article{MoremiClausVogeletal.2017, author = {Moremi, Nyambura and Claus, Heike and Vogel, Ulrich and Mshana, Stephen E.}, title = {Surveillance of surgical site infections by Pseudomonas aeruginosa and strain characterization in Tanzanian hospitals does not provide proof for a role of hospital water plumbing systems in transmission}, series = {Antimicrobial Resistance and Infection Control}, volume = {6}, journal = {Antimicrobial Resistance and Infection Control}, number = {56}, doi = {10.1186/s13756-017-0216-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-158168}, year = {2017}, abstract = {Background The role of hospital water systems in the development of Pseudomonas aeruginosa (P. aeruginosa) surgical site infections (SSIs) in low-income countries is barely studied. This study characterized P. aeruginosa isolates from patients and water in order to establish possible epidemiological links. Methods: Between December 2014 and September 2015, rectal and wound swabs, and water samples were collected in the frame of active surveillance for SSIs in the two Tanzanian hospitals. Typing of P. aeruginosa was done by multi-locus sequence typing. Results: Of 930 enrolled patients, 536 were followed up, of whom 78 (14.6\%, 95\% CI; 11.6-17.5) developed SSIs. P. aeruginosa was found in eight (14\%) of 57 investigated wounds. Of the 43 water sampling points, 29 were positive for P. aeruginosa. However, epidemiological links to wound infections were not confirmed. The P. aeruginosa carriage rate on admission was 0.9\% (8/930). Of the 363 patients re-screened upon discharge, four (1.1\%) possibly acquired P. aeruginosa during hospitalization. Wound infections of the three of the eight P. aeruginosa SSIs were caused by a strain of the same sequence type (ST) as the one from intestinal carriage. Isolates from patients were more resistant to antibiotics than water isolates. Conclusions: The P. aeruginosa SSI rate was low. There was no evidence for transmission from tap water. Not all P. aeruginosa SSI were proven to be endogenous, pointing to other routes of transmission.}, language = {en} } @article{DoranFuldeGratzetal.2016, author = {Doran, Kelly S. and Fulde, Marcus and Gratz, Nina and Kim, Brandon J. and Nau, Roland and Prasadarao, Nemani and Schubert-Unkmeir, Alexandra and Tuomanen, Elaine I. and Valentin-Weigand, Peter}, title = {Host-pathogen interactions in bacterial meningitis}, series = {Acta Neuropathologica}, volume = {131}, journal = {Acta Neuropathologica}, number = {2}, doi = {10.1007/s00401-015-1531-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-191034}, pages = {185-209}, year = {2016}, abstract = {Bacterial meningitis is a devastating disease occurring worldwide with up to half of the survivors left with permanent neurological sequelae. Due to intrinsic properties of the meningeal pathogens and the host responses they induce, infection can cause relatively specific lesions and clinical syndromes that result from interference with the function of the affected nervous system tissue. Pathogenesis is based on complex host-pathogen interactions, some of which are specific for certain bacteria, whereas others are shared among different pathogens. In this review, we summarize the recent progress made in understanding the molecular and cellular events involved in these interactions. We focus on selected major pathogens, Streptococcus pneumonia, S. agalactiae (Group B Streptococcus), Neisseria meningitidis, and Escherichia coli K1, and also include a neglected zoonotic pathogen, Streptococcus suis. These neuroinvasive pathogens represent common themes of host-pathogen interactions, such as colonization and invasion of mucosal barriers, survival in the blood stream, entry into the central nervous system by translocation of the blood-brain and blood-cerebrospinal fluid barrier, and induction of meningeal inflammation, affecting pia mater, the arachnoid and subarachnoid spaces.}, language = {en} } @article{HerrmannMuenstermannStrobeletal.2018, author = {Herrmann, Johannes and Muenstermann, Marcel and Strobel, Lea and Schubert-Unkmeir, Alexandra and Woodruff, Trent M. and Gray-Owen, Scott D. and Klos, Andreas and Johswich, Kay O.}, title = {Complement C5a receptor 1 exacerbates the pathophysiology of N. meningitidis sepsis and is a potential target for disease treatment}, series = {mBio}, volume = {9}, journal = {mBio}, number = {1}, doi = {10.1128/mBio.01755-17}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175792}, pages = {e01755-17}, year = {2018}, abstract = {Sepsis caused by Neisseria meningitidis (meningococcus) is a rapidly progressing, life-threatening disease. Because its initial symptoms are rather unspecific, medical attention is often sought too late, i.e., when the systemic inflammatory response is already unleashed. This in turn limits the success of antibiotic treatment. The complement system is generally accepted as the most important innate immune determinant against invasive meningococcal disease since it protects the host through the bactericidal membrane attack complex. However, complement activation concomitantly liberates the C5a peptide, and it remains unclear whether this potent anaphylatoxin contributes to protection and/or drives the rapidly progressing immunopathogenesis associated with meningococcal disease. Here, we dissected the specific contribution of C5a receptor 1 (C5aR1), the canonical receptor for C5a, using a mouse model of meningococcal sepsis. Mice lacking C3 or C5 displayed susceptibility that was enhanced by >1,000-fold or 100-fold, respectively, consistent with the contribution of these components to protection. In clear contrast, C5ar1\(^{-/-}\) mice resisted invasive meningococcal infection and cleared N. meningitidis more rapidly than wild-type (WT) animals. This favorable outcome stemmed from an ameliorated inflammatory cytokine response to N. meningitidis in C5ar1\(^{-/-}\) mice in both in vivo and ex vivo whole-blood infections. In addition, inhibition of C5aR1 signaling without interference with the complement bactericidal activity reduced the inflammatory response also in human whole blood. Enticingly, pharmacologic C5aR1 blockade enhanced mouse survival and lowered meningococcal burden even when the treatment was administered after sepsis induction. Together, our findings demonstrate that C5aR1 drives the pathophysiology associated with meningococcal sepsis and provides a promising target for adjunctive therapy. Importance: The devastating consequences of N. meningitidis sepsis arise due to the rapidly arising and self-propagating inflammatory response that mobilizes antibacterial defenses but also drives the immunopathology associated with meningococcemia. The complement cascade provides innate broad-spectrum protection against infection by directly damaging the envelope of pathogenic microbes through the membrane attack complex and triggers an inflammatory response via the C5a peptide and its receptor C5aR1 aimed at mobilizing cellular effectors of immunity. Here, we consider the potential of separating the bactericidal activities of the complement cascade from its immune activating function to improve outcome of N. meningitidis sepsis. Our findings demonstrate that the specific genetic or pharmacological disruption of C5aR1 rapidly ameliorates disease by suppressing the pathogenic inflammatory response and, surprisingly, allows faster clearance of the bacterial infection. This outcome provides a clear demonstration of the therapeutic benefit of the use of C5aR1-specific inhibitors to improve the outcome of invasive meningococcal disease.}, language = {en} } @article{BauriedlGerovacHeidrichetal.2020, author = {Bauriedl, Saskia and Gerovac, Milan and Heidrich, Nadja and Bischler, Thorsten and Barquist, Lars and Vogel, J{\"o}rg and Schoen, Christoph}, title = {The minimal meningococcal ProQ protein has an intrinsic capacity for structure-based global RNA recognition}, series = {Nature Communications}, volume = {11}, journal = {Nature Communications}, doi = {10.1038/s41467-020-16650-6}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230040}, year = {2020}, abstract = {FinO-domain proteins are a widespread family of bacterial RNA-binding proteins with regulatory functions. Their target spectrum ranges from a single RNA pair, in the case of plasmid-encoded FinO, to global RNA regulons, as with enterobacterial ProQ. To assess whether the FinO domain itself is intrinsically selective or promiscuous, we determine in vivo targets of Neisseria meningitidis, which consists of solely a FinO domain. UV-CLIP-seq identifies associations with 16 small non-coding sRNAs and 166 mRNAs. Meningococcal ProQ predominantly binds to highly structured regions and generally acts to stabilize its RNA targets. Loss of ProQ alters transcript levels of >250 genes, demonstrating that this minimal ProQ protein impacts gene expression globally. Phenotypic analyses indicate that ProQ promotes oxidative stress resistance and DNA damage repair. We conclude that FinO domain proteins recognize some abundant type of RNA shape and evolve RNA binding selectivity through acquisition of additional regions that constrain target recognition. FinO-domain proteins are bacterial RNA-binding proteins with a wide range of target specificities. Here, the authors employ UV CLIP-seq and show that minimal ProQ protein of Neisseria meningitidis binds to various small non-coding RNAs and mRNAs involved in virulence.}, language = {en} } @article{GomesWestermannSauerweinetal.2019, author = {Gomes, Sara F. Martins and Westermann, Alexander J. and Sauerwein, Till and Hertlein, Tobias and F{\"o}rstner, Konrad U. and Ohlsen, Knut and Metzger, Marco and Shusta, Eric V. and Kim, Brandon J. and Appelt-Menzel, Antje and Schubert-Unkmeir, Alexandra}, title = {Induced pluripotent stem cell-derived brain endothelial cells as a cellular model to study Neisseria meningitidis infection}, series = {Frontiers in Microbiology}, volume = {10}, journal = {Frontiers in Microbiology}, number = {1181}, doi = {10.3389/fmicb.2019.01181}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-201562}, year = {2019}, abstract = {Meningococcal meningitis is a severe central nervous system infection that occurs when Neisseria meningitidis (Nm) penetrates brain endothelial cells (BECs) of the meningeal blood-cerebrospinal fluid barrier. As a human-specific pathogen, in vivo models are greatly limited and pose a significant challenge. In vitro cell models have been developed, however, most lack critical BEC phenotypes limiting their usefulness. Human BECs generated from induced pluripotent stem cells (iPSCs) retain BEC properties and offer the prospect of modeling the human-specific Nm interaction with BECs. Here, we exploit iPSC-BECs as a novel cellular model to study Nm host-pathogen interactions, and provide an overview of host responses to Nm infection. Using iPSC-BECs, we first confirmed that multiple Nm strains and mutants follow similar phenotypes to previously described models. The recruitment of the recently published pilus adhesin receptor CD147 underneath meningococcal microcolonies could be verified in iPSC-BECs. Nm was also observed to significantly increase the expression of pro-inflammatory and neutrophil-specific chemokines IL6, CXCL1, CXCL2, CXCL8, and CCL20, and the secretion of IFN-γ and RANTES. For the first time, we directly observe that Nm disrupts the three tight junction proteins ZO-1, Occludin, and Claudin-5, which become frayed and/or discontinuous in BECs upon Nm challenge. In accordance with tight junction loss, a sharp loss in trans-endothelial electrical resistance, and an increase in sodium fluorescein permeability and in bacterial transmigration, was observed. Finally, we established RNA-Seq of sorted, infected iPSC-BECs, providing expression data of Nm-responsive host genes. Altogether, this model provides novel insights into Nm pathogenesis, including an impact of Nm on barrier properties and tight junction complexes, and suggests that the paracellular route may contribute to Nm traversal of BECs.}, language = {en} } @phdthesis{Peters2021, author = {Peters, Simon}, title = {The impact of sphingolipids on \(Neisseria\) \(meningitidis\) and their role in meningococcal pathogenicity}, doi = {10.25972/OPUS-22623}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-226233}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {The obligate human pathogen Neisseria meningitidis is a major cause of sepsis and meningitis worldwide. It affects mainly toddlers and infants and is responsible for thousands of deaths each year. In this study, different aspects of the importance of sphingolipids in meningococcal pathogenicity were investigated. In a first step, the acid sphingomyelinase (ASM), which degrades membrane sphingomyelin to ceramide, was studied in the context of meningococcal infection. A requirement for ASM surface activity is its translocation from the lysosomal compartment to the cell surface, a process that is currently poorly understood. This study used various approaches, including classical invasion and adherence assays, flow cytometry, and classical and super resolution immunofluorescence microscopy (dSTORM). The results showed that the live, highly piliated N. meningitidis strain 8013/12 induced calcium-dependent ASM translocation in human brain microvascular endothelial cells (HBMEC). Furthermore, it promoted the formation of ceramide-rich platforms (CRPs). In addition, ASM translocation and CRP formation were observed after treating the cells with pili-enriched fractions derived from the same strain. The importance for N. meningitidis to utilize this pathway was shown by the inhibition of the calcium-dependent ASM translocation, which greatly decreased the number of invasive bacteria. I also investigated the importance of the glycosphingolipids GM1 and Gb3. The results showed that GM1, but not Gb3, plays an important role in the ability of N. meningitidis to invade HBMEC. By combining dSTORM imaging and microbiological approaches, we demonstrated that GM1 accumulated prolifically around bacteria during the infection, and that this interaction seemed essential for meningococcal invasion. Sphingolipids are not only known for their beneficial effect on pathogens. Sphingoid bases, including sphingosine, are known for their antimicrobial activity. In the last part of this study, a novel correlative light and electron microscopy approach was established in the combination with click chemistry to precisely localize azido-functionalized sphingolipids in N. meningitidis. The result showed a distinct concentration-dependent localization in either the outer membrane (low concentration) or accumulated in the cytosol (high concentration). This pattern was confirmed by mass spectrometry on separated membrane fractions. Our data provide a first insight into the underlying mechanism of antimicrobial sphingolipids.}, subject = {Neisseria meningitidis}, language = {en} } @phdthesis{Bauriedl2020, author = {Bauriedl, Saskia Corinna}, title = {The influence of riboregulation on fitness and virulence in Neisseria meningitidis}, doi = {10.25972/OPUS-19297}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-192978}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2020}, abstract = {Neisseria meningitidis (N. meningitidis) is a human commensal that occasionally causes life-threatening infections such as bacterial meningitis and septicemia. Despite experi-mental evidence that the expression of small non-coding RNAs (sRNAs) as well as the RNA chaperone Hfq affect meningococcal physiology, the impact of RNA-based regula-tion (riboregulation) on fitness and virulence in N. meningitidis is only poorly understood. Therefore, this study addressed these issues using a combination of high-throughput tech-nologies. A differential RNA-sequencing (dRNA-seq) approach was applied to produce a single-nucleotide resolution map of the primary transcriptome of N. meningitidis strain 8013. The dRNA-seq analysis predicted 1,625 transcriptional start sites including 65 putative sRNAs, of which 20 were further validated by northern blot analysis. By Hfq RNA im-munopreci-pitation sequencing a large Hfq-centered post-transcriptional regulatory net-work comprising 23 sRNAs and 401 potential mRNA targets was identified. Rifampicin stability assays demonstrated that Hfq binding confers enhanced stability on its associat-ed sRNAs. Based on these data, the interactions of two paralogous sRNAs and their cog-nate target mRNA prpB were validated in vivo as well as in vitro. Both sRNAs directly repress prpB encoding a methylisocitrate lyse which was previously shown to be involved in meningococcal colonization of the human nasopharynx. Besides the well-described RNA chaperone Hfq, FinO-domain proteins have recently been recognized as a widespread family of RNA-binding proteins (RBPs) with regulatory roles in diverse bacteria. They display an intriguing bandwidth of target sites, ranging from a single RNA pair as recognized by plasmid-encoded FinO to the global RNA regu-lons of enterobacterial ProQ proteins. To better understand the intrinsic targeting mode of this RBP family, in vivo targets of the minimal ProQ protein of N. meningitidis were de-termined. In vivo UV crosslinking with RNA deep sequencing (UV-CLIP) identified as-sociations of ProQ with 16 sRNAs and 166 mRNAs encoding a variety of biological functions and thus revealed ProQ as another global RBP in meningococci. It could be shown that meningococcal ProQ predominantly binds to highly structured RNA regions including DNA uptake sequences (DUS) and rho-independent transcription terminators and stabilizes many of its RNA targets as proved by rifampicin stability experiments. As expected from the large suite of ProQ-bound RNAs, proQ deletion globally affects both gene and protein expression in N. meningitidis, changing the expression levels of at least 244 mRNAs and 80 proteins. Phenotypic analyses suggested that ProQ promotes oxida-tive stress tolerance and UV damage repair capacity, both of which are required for full virulence of N. meningitidis. Together, this work uncovers the co-existence of two major post-transcriptional regulons, one governed by ProQ, the other by Hfq, in N. meningitidis. It further highlights the role of these distinct RBPs and its associated sRNAs to bacterial virulence and indicates that riboregulation is likely to contribute to the way how meningococci adapt to different host niches.}, subject = {Neisseria meningitidis}, language = {en} } @article{EndresJungblutDivyapicigiletal.2022, author = {Endres, Leo M. and Jungblut, Marvin and Divyapicigil, Mustafa and Sauer, Markus and Stigloher, Christian and Christodoulides, Myron and Kim, Brandon J. and Schubert-Unkmeir, Alexandra}, title = {Development of a multicellular in vitro model of the meningeal blood-CSF barrier to study Neisseria meningitidis infection}, series = {Fluids and Barriers of the CNS}, volume = {19}, journal = {Fluids and Barriers of the CNS}, number = {1}, doi = {10.1186/s12987-022-00379-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300208}, year = {2022}, abstract = {Background Bacterial meningitis is a life-threatening disease that occurs when pathogens such as Neisseria meningitidis cross the meningeal blood cerebrospinal fluid barrier (mBCSFB) and infect the meninges. Due to the human-specific nature of N. meningitidis, previous research investigating this complex host-pathogen interaction has mostly been done in vitro using immortalized brain endothelial cells (BECs) alone, which often do not retain relevant barrier properties in culture. Here, we developed physiologically relevant mBCSFB models using BECs in co-culture with leptomeningeal cells (LMCs) to examine N. meningitidis interaction. Methods We used BEC-like cells derived from induced pluripotent stem cells (iBECs) or hCMEC/D3 cells in co-culture with LMCs derived from tumor biopsies. We employed TEM and structured illumination microscopy to characterize the models as well as bacterial interaction. We measured TEER and sodium fluorescein (NaF) permeability to determine barrier tightness and integrity. We then analyzed bacterial adherence and penetration of the cell barrier and examined changes in host gene expression of tight junctions as well as chemokines and cytokines in response to infection. Results Both cell types remained distinct in co-culture and iBECs showed characteristic expression of BEC markers including tight junction proteins and endothelial markers. iBEC barrier function as determined by TEER and NaF permeability was improved by LMC co-culture and remained stable for seven days. BEC response to N. meningitidis infection was not affected by LMC co-culture. We detected considerable amounts of BEC-adherent meningococci and a relatively small number of intracellular bacteria. Interestingly, we discovered bacteria traversing the BEC-LMC barrier within the first 24 h post-infection, when barrier integrity was still high, suggesting a transcellular route for N. meningitidis into the CNS. Finally, we observed deterioration of barrier properties including loss of TEER and reduced expression of cell-junction components at late time points of infection. Conclusions Here, we report, for the first time, on co-culture of human iPSC derived BECs or hCMEC/D3 with meningioma derived LMCs and find that LMC co-culture improves barrier properties of iBECs. These novel models allow for a better understanding of N. meningitidis interaction at the mBCSFB in a physiologically relevant setting.}, language = {en} } @article{ForsterKohlmorgenHaasetal.2022, author = {Forster, Johannes and Kohlmorgen, Britta and Haas, Julian and Weis, Philipp and Breunig, Lukas and Turnwald, Doris and Mizaikoff, Boris and Schoen, Christoph}, title = {A streamlined method for the fast and cost-effective detection of bacterial pathogens from positive blood cultures for the BacT/ALERT blood culture system using the Vitek MS mass spectrometer}, series = {PLoS ONE}, volume = {17}, journal = {PLoS ONE}, number = {4}, doi = {10.1371/journal.pone.0267669}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-300213}, year = {2022}, abstract = {Background and objective Prompt pathogen identification of blood stream infections is essential to provide appropriate antibiotic treatment. Therefore, the objective of this prospective single centre study was to establish an inexpensive, fast and accurate protocol for bacterial species identification with SDS protein-extraction directly from BacT/Alert® blood culture (BC) bottles by VitekMS®. Results Correct species identification was obtained for 198/266 (74.4\%, 95\%-CI = [68.8\%, 79.6\%]) of pathogens. The protocol was more successful in identifying 87/96 (91.4\%, 95\%-CI = [83.8\%, 93.2\%]) gram-negative bacteria than 110/167 (65.9\%, 95\%-CI = [58.1\%, 73.0\%]) gram-positive bacteria. The hands-on time for sample preparation and measurement was about 15 min for up to five samples. This is shorter than for most other protocols using a similar lysis-centrifugation approach for the combination of BacT/Alert® BC bottles and the Vitek® MS mass spectrometer. The estimated costs per sample were approx. 1.80€ which is much cheaper than for commercial kits. Conclusion This optimized protocol allows for accurate identification of bacteria directly from blood culture bottles for laboratories equipped with BacT/Alert® blood culture bottles and VitekMS® mass spectrometer.}, language = {en} } @article{MuenstermannStrobelKlosetal.2019, author = {Muenstermann, Marcel and Strobel, Lea and Klos, Andreas and Wetsel, Rick A. and Woodruff, Trent M. and K{\"o}hl, J{\"o}rg and Johswich, Kay O.}, title = {Distinct roles of the anaphylatoxin receptors C3aR, C5aR1 and C5aR2 in experimental meningococcal infections}, series = {Virulence}, volume = {10}, journal = {Virulence}, number = {1}, doi = {10.1080/21505594.2019.1640035}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200496}, pages = {677-694}, year = {2019}, abstract = {The complement system is pivotal in the defense against invasive disease caused by Neisseria meningitidis (Nme, meningococcus), particularly via the membrane attack complex. Complement activation liberates the anaphylatoxins C3a and C5a, which activate three distinct G-protein coupled receptors, C3aR, C5aR1 and C5aR2 (anaphylatoxin receptors, ATRs). We recently discovered that C5aR1 exacerbates the course of the disease, revealing a downside of complement in Nme sepsis. Here, we compared the roles of all three ATRs during mouse nasal colonization, intraperitoneal infection and human whole blood infection with Nme. Deficiency of complement or ATRs did not alter nasal colonization, but significantly affected invasive disease: Compared to WT mice, the disease was aggravated in C3ar\(^{-/-}\) mice, whereas C5ar1\(^{-/-}\) and C5ar2\(^{-/-}\) mice showed increased resistance to meningococcal sepsis. Surprisingly, deletion of either of the ATRs resulted in lower cytokine/chemokine responses, irrespective of the different susceptibilities of the mice. This was similar in ex vivo human whole blood infection using ATR inhibitors. Neutrophil responses to Nme were reduced in C5ar1\(^{-/-}\) mouse blood. Upon stimulation with C5a plus Nme, mouse macrophages displayed reduced phosphorylation of ERK1/2, when C5aR1 or C5aR2 were ablated or inhibited, suggesting that both C5a-receptors prime an initial macrophage response to Nme. Finally, in vivo blockade of C5aR1 alone (PMX205) or along with C5aR2 (A8\(^{Δ71-73}\)) resulted in ameliorated disease, whereas neither antagonizing C3aR (SB290157) nor its activation with a "super-agonist" peptide (WWGKKYRASKLGLAR) demonstrated a benefit. Thus, C5aR1 and C5aR2 augment disease pathology and are interesting targets for treatment, whereas C3aR is protective in experimental meningococcal sepsis.}, language = {en} } @article{WurmbScholtesKolibayetal.2020, author = {Wurmb, Thomas and Scholtes, Katja and Kolibay, Felix and Schorscher, Nora and Ertl, Georg and Ernestus, Ralf-Ingo and Vogel, Ulrich and Franke, Axel and Kowalzik, Barbara}, title = {Hospital preparedness for mass critical care during SARS-CoV-2 pandemic}, series = {Critical Care}, volume = {24}, journal = {Critical Care}, doi = {10.1186/s13054-020-03104-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230201}, year = {2020}, abstract = {Mass critical care caused by the severe acute respiratory syndrome corona virus 2 pandemic poses an extreme challenge to hospitals. The primary goal of hospital disaster preparedness and response is to maintain conventional or contingency care for as long as possible. Crisis care must be delayed as long as possible by appropriate measures. Increasing the intensive care unit (ICU) capacities is essential. In order to adjust surge capacity, the reduction of planned, elective patient care is an adequate response. However, this involves numerous problems that must be solved with a sense of proportion. This paper summarises preparedness and response measures recommended to acute care hospitals.}, language = {en} } @article{PetersKaiserFinketal.2021, author = {Peters, Simon and Kaiser, Lena and Fink, Julian and Schumacher, Fabian and Perschin, Veronika and Schlegel, Jan and Sauer, Markus and Stigloher, Christian and Kleuser, Burkhard and Seibel, Juergen and Schubert-Unkmeir, Alexandra}, title = {Click-correlative light and electron microscopy (click-AT-CLEM) for imaging and tracking azido-functionalized sphingolipids in bacteria}, series = {Scientific Reports}, volume = {11}, journal = {Scientific Reports}, number = {1}, doi = {10.1038/s41598-021-83813-w}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-259147}, pages = {4300}, year = {2021}, abstract = {Sphingolipids, including ceramides, are a diverse group of structurally related lipids composed of a sphingoid base backbone coupled to a fatty acid side chain and modified terminal hydroxyl group. Recently, it has been shown that sphingolipids show antimicrobial activity against a broad range of pathogenic microorganisms. The antimicrobial mechanism, however, remains so far elusive. Here, we introduce 'click-AT-CLEM', a labeling technique for correlated light and electron microscopy (CLEM) based on the super-resolution array tomography (srAT) approach and bio-orthogonal click chemistry for imaging of azido-tagged sphingolipids to directly visualize their interaction with the model Gram-negative bacterium Neisseria meningitidis at subcellular level. We observed ultrastructural damage of bacteria and disruption of the bacterial outer membrane induced by two azido-modified sphingolipids by scanning electron microscopy and transmission electron microscopy. Click-AT-CLEM imaging and mass spectrometry clearly revealed efficient incorporation of azido-tagged sphingolipids into the outer membrane of Gram-negative bacteria as underlying cause of their antimicrobial activity.}, language = {en} } @article{SilwedelSpeerHaarmannetal.2018, author = {Silwedel, Christine and Speer, Christian P. and Haarmann, Axel and Fehrholz, Markus and Claus, Heike and Buttmann, Mathias and Glaser, Kirsten}, title = {Novel insights into neuroinflammation: bacterial lipopolysaccharide, tumor necrosis factor α, and Ureaplasma species differentially modulate atypical chemokine receptor 3 responses in human brain microvascular endothelial cells}, series = {Journal of Neuroinflammation}, volume = {15}, journal = {Journal of Neuroinflammation}, number = {156}, doi = {10.1186/s12974-018-1170-0}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-175952}, year = {2018}, abstract = {Background: Atypical chemokine receptor 3 (ACKR3, synonym CXCR7) is increasingly considered relevant in neuroinflammatory conditions, in which its upregulation contributes to compromised endothelial barrier function and may ultimately allow inflammatory brain injury. While an impact of ACKR3 has been recognized in several neurological autoimmune diseases, neuroinflammation may also result from infectious agents, including Ureaplasma species (spp.). Although commonly regarded as commensals of the adult urogenital tract, Ureaplasma spp. may cause invasive infections in immunocompromised adults as well as in neonates and appear to be relevant pathogens in neonatal meningitis. Nonetheless, clinical and in vitro data on Ureaplasma-induced inflammation are scarce. Methods: We established a cell culture model of Ureaplasma meningitis, aiming to analyze ACKR3 variances as a possible pathomechanism in Ureaplasma-associated neuroinflammation. Non-immortalized human brain microvascular endothelial cells (HBMEC) were exposed to bacterial lipopolysaccharide (LPS) or tumor necrosis factor-α (TNF-α), and native as well as LPS-primed HBMEC were cultured with Ureaplasma urealyticum serovar 8 (Uu8) and U. parvum serovar 3 (Up3). ACKR3 responses were assessed via qRT-PCR, RNA sequencing, flow cytometry, and immunocytochemistry. Results: LPS, TNF-α, and Ureaplasma spp. influenced ACKR3 expression in HBMEC. LPS and TNF-α significantly induced ACKR3 mRNA expression (p < 0.001, vs. control), whereas Ureaplasma spp. enhanced ACKR3 protein expression in HBMEC (p < 0.01, vs. broth control). Co-stimulation with LPS and either Ureaplasma isolate intensified ACKR3 responses (p < 0.05, vs. LPS). Furthermore, stimulation wielded a differential influence on the receptor's ligands. Conclusions: We introduce an in vitro model of Ureaplasma meningitis. We are able to demonstrate a pro-inflammatory capacity of Ureaplasma spp. in native and, even more so, in LPS-primed HBMEC, underlining their clinical relevance particularly in a setting of co-infection. Furthermore, our data may indicate a novel role for ACKR3, with an impact not limited to auto-inflammatory diseases, but extending to infection-related neuroinflammation as well. AKCR3-induced blood-brain barrier breakdown might constitute a potential common pathomechanism.}, language = {en} } @article{StrobelJohswich2018, author = {Strobel, Lea and Johswich, Kay O.}, title = {Anticoagulants impact on innate immune responses and bacterial survival in whole blood models of Neisseria meningitidis infection}, series = {Scientific Reports}, volume = {8}, journal = {Scientific Reports}, number = {10225}, doi = {10.1038/s41598-018-28583-8}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-176226}, year = {2018}, abstract = {Neisseria meningitidis (meningococcus) causes invasive diseases such as meningitis or septicaemia. Ex vivo infection of human whole blood is a valuable tool to study meningococcal virulence factors and the host innate immune responses. In order to consider effects of cellular mediators, the coagulation cascade must be inhibited to avoid clotting. There is considerable variation in the anticoagulants used among studies of N. meningitidis whole blood infections, featuring citrate, heparin or derivatives of hirudin, a polypeptide from leech saliva. Here, we compare the influence of these three different anticoagulants, and additionally Mg/EGTA, on host innate immune responses as well as on viability of N. meningitidis strains isolated from healthy carriers and disease cases, reflecting different sequence types and capsule phenotypes. We found that the anticoagulants significantly impact on cellular responses and, strain-dependently, also on bacterial survival. Hirudin does not inhibit complement and is therefore superior over the other anticoagulants; indeed hirudin-plasma most closely reflects the characteristics of serum during N. meningitidis infection. We further demonstrate the impact of heparin on complement activation on N. meningitidis and its consequences on meningococcal survival in immune sera, which appears to be independent of the heparin binding antigens Opc and NHBA.}, language = {en} } @article{GoetzPanzerTrinksetal.2020, author = {G{\"o}tz, Ralph and Panzer, Sabine and Trinks, Nora and Eilts, Janna and Wagener, Johannes and Turr{\`a}, David and Di Pietro, Antonio and Sauer, Markus and Terpitz, Ulrich}, title = {Expansion Microscopy for Cell Biology Analysis in Fungi}, series = {Frontiers in Microbiology}, volume = {11}, journal = {Frontiers in Microbiology}, issn = {1664-302X}, doi = {10.3389/fmicb.2020.00574}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202569}, year = {2020}, abstract = {Super-resolution microscopy has evolved as a powerful method for subdiffraction-resolution fluorescence imaging of cells and cellular organelles, but requires sophisticated and expensive installations. Expansion microscopy (ExM), which is based on the physical expansion of the cellular structure of interest, provides a cheap alternative to bypass the diffraction limit and enable super-resolution imaging on a conventional fluorescence microscope. While ExM has shown impressive results for the magnified visualization of proteins and RNAs in cells and tissues, it has not yet been applied in fungi, mainly due to their complex cell wall. Here we developed a method that enables reliable isotropic expansion of ascomycetes and basidiomycetes upon treatment with cell wall degrading enzymes. Confocal laser scanning microscopy (CLSM) and structured illumination microscopy (SIM) images of 4.5-fold expanded sporidia of Ustilago maydis expressing fluorescent fungal rhodopsins and hyphae of Fusarium oxysporum or Aspergillus fumigatus expressing either histone H1-mCherry together with Lifeact-sGFP or mRFP targeted to mitochondria, revealed details of subcellular structures with an estimated spatial resolution of around 30 nm. ExM is thus well suited for cell biology studies in fungi on conventional fluorescence microscopes.}, language = {en} } @article{ForsterDichtlWagener2022, author = {Forster, Johannes and Dichtl, Karl and Wagener, Johannes}, title = {Lower beta-1,3-D-glucan testing cut-offs increase sensitivity for non-albicans Candida species bloodstream infections}, series = {Mycoses}, volume = {65}, journal = {Mycoses}, number = {5}, doi = {10.1111/myc.13421}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-276515}, pages = {500 -- 507}, year = {2022}, abstract = {Purpose Fungal biomarkers support early diagnosis of invasive fungal infections. In this study, we evaluated the impact of a recent update to the manufacturer-recommended cut-off for beta-1,3-D-glucan (BDG) testing (Fujifilm Wako BDG assay) on sensitivity and specificity for the detection of candidemia. Additionally, we compared the performance with tests for Candida antigen (Ag by Serion ELISA antigen Candida, Virion\Serion) and anti-mannan antibodies (Ab by Hemkit Candida IHA, Ravo Diagnostika). Methods Sera of 82 patients with candidemia, which were sampled with a maximum distance of ±14 days from the date of sampling of the corresponding positive blood cultures, were retrospectively analysed for BDG, Ag and Ab. Results of BDG testing were compared with results from sera of 129 patients with candidemia from a different hospital. Results Sensitivity of BDG testing (47\%) was higher than for Ag (17\%) or Ab (20\%). By combining Ag and Ab testing, sensitivity was raised to 32\%. Lowering the cut-off of BDG from 11 pg/ml to the newly recommended cut-off of 7 pg/ml resulted in a significant increase in sensitivity (47\% vs 58\%, p = .01 and 63\% vs 71\% p < .01). At both centres, the increase was significant in NAC but not in C. albicans candidemia. No significant effects on specificity were observed. Conclusion BDG testing outperformed Ag and Ab testing and its combination. Lowering the BDG cut-off had no significant impact on specificity. The increase in sensitivity can be mainly attributed to a gain in sensitivity for non-albicans Candida species bloodstream infections.}, language = {en} } @phdthesis{Herrmann2023, author = {Herrmann, Ruth Magdalena}, title = {Molekular- und zellbiologische Untersuchung zur Rolle des kanonischen Wnt-Signalwegs bei der Entwicklung von \(Echinococcus\) \(multilocularis\)}, doi = {10.25972/OPUS-27193}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-271937}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2023}, abstract = {Die alveol{\"a}re Echinokokkose (AE) ist eine lebensbedrohliche Erkrankung des Menschen, welche durch das infiltrative Wachstum des Metazestoden-Larvenstadiums des Fuchsbandwurms (Echinococcus multilocularis) in der Leber verursacht wird. Das tumorartige Wachstum des Metazestoden beruht auf einer Echinococcus-spezifischen Modifikation der anterior-posterioren-K{\"o}rperachse (AP Achse). Es wird vermutet, dass dabei der anteriore Pol der invadierenden Oncosp{\"a}ren-Larve zun{\"a}chst abgeschaltet wird und sich der Metazestode anschließend asexuell als vesikul{\"a}res, posteriorisiertes Gewebes im Wirt vermehrt. Nach massiver Proliferation wird der anteriore Pol reetabliert und f{\"u}hrt zur Bildung zahlreicher Bandwurm-Kopfanlagen (Protoskolizes). Da die Ausbildung der AP K{\"o}rperachse evolutionsgeschichtlich konserviert {\"u}ber den wingless-related (Wnt)-Signalweg gesteuert wird, wurde in dieser Arbeit die Rolle von Wnt-Signaling bei der Musterbildung von E. multilocularis {\"u}ber molekular- und zellbiologische Studien n{\"a}her beleuchtet. Zentraler methodischer Ansatz der vorliegenden Arbeit war ein E. multilocularis Stammzell-Kultursystem, das Prim{\"a}rzellsystem, welches die in vitro-Generierung von Metazestoden-Vesikeln durch Proliferation und Differenzierung von germinativen Zellen (Stammzellen) erlaubt. {\"U}ber RNA-Sequenzierung wurde zun{\"a}chst gezeigt, dass in Prim{\"a}rzellkulturen sowohl Markergene f{\"u}r posteriore Entwicklung in Richtung Metazestode wie auch f{\"u}r Anterior-und Protoskolexmarker exprimiert werden. Unter Verwendung von RNA-Interferenz (RNAi) wurde anschließend ein erfolgreicher Knockdown des vermuteten Hauptregulators des kanonischen Wnt-Signalwegs, β Catenin (em-bcat1), erreicht und f{\"u}hrte zu einem charakteristischen, sogenannten ‚red dot' Ph{\"a}notyp, dem ersten jemals beschriebenen RNAi Ph{\"a}notyp f{\"u}r E. multilocularis-Prim{\"a}rzellen. Prim{\"a}rzellkulturen nach em-bcat1 RNAi zeigten eine stark verminderte F{\"a}higkeit, Metazestoden-Vesikel zu bilden sowie eine {\"U}berproliferation von germinativen Zellen. Zus{\"a}tzliche RNA-Seq-Analysen des Transkriptoms von RNAi(em-bcat1)-Kulturen zeigten eine signifikant verringerte Expression von Posterior- und Metazestodenmarkern, w{\"a}hrend Anterior- und Protoskolexmarker deutlich {\"u}berexprimiert wurden. Durch umfangreiche Whole-mount-in-situ-Hybridisierung (WMISH)-Experimente wurden diese Daten f{\"u}r eine Reihe ausgew{\"a}hlter Markergene f{\"u}r posteriore (Metazestode; em-wnt1, em-wnt11b, em-muc1) und f{\"u}r anteriore Entwicklung (Protoskolex; em sfrp, em-nou-darake, em npp36, em-frizzled10) verifiziert. In allen genannten F{\"a}llen zeigte sich durch {\"A}nderung der Polarit{\"a}t eine verminderte Genexpression von Posteriormarkern, w{\"a}hrend Anteriormarker deutlich erh{\"o}ht exprimiert wurden. {\"A}hnlich wie bei den verwandten, freilebenden Planarien, f{\"u}hrt demnach ein Knockdown des zentralen Wnt-Regulators β-Catenin bei E. multilocularis zu einer anteriorisierten, Anterior- und Protoskolexmarker dominierte Genexpression, welche der posteriorisierten Entwicklung zum Metazestoden entgegenwirkt. Neben Markergenen f{\"u}r die Ausbildung der AP-Achse wurden in dieser Arbeit auch solche f{\"u}r die medio-laterale (ML)-K{\"o}rperachse bei Zestoden erstmals beschrieben. So zeigte sich, dass ein Slit-Ortholog (em slit) im E. multilocularis Protoskolex im Bereich der K{\"o}rper-Mittellinie exprimiert wird und lieferte Hinweise darauf, dass, {\"a}hnlich zur Situation bei Planarien, die ML Achse von E. multilocularis durch Morphogengradienten aus slit (Mittellinie) und wnt5 (lateral) definiert wird. Im Metazestoden wird hingegen nur em-slit exprimiert. Der Metazestode besitzt damit als posterior-medianisiertes Gewebe Anlagen zur Polarit{\"a}t zur AP- und ML-Achse, welche erst mit Bildung von Protoskolizes vollst{\"a}ndig etabliert werden. Schließlich deuten die Ergebnisse dieser Arbeit darauf hin, dass bei der Wiederherstellung der K{\"o}rperachsen w{\"a}hrend der Entwicklung von Protoskolizes Hedgehog (Hh)-Signale entscheidend mitwirken. Zusammenfassend wurde in dieser Arbeit der zentrale Faktor des kanonischen Wnt Signalwegs, β-Catenin, als Hauptregulator der Entwicklung des tumorartig wachsenden E. multilocularis-Metazestoden identifiziert. Zudem wurde gezeigt, dass zur Metazestodenbildung neben einer Echinococcus-spezifischen Modifikation der AP K{\"o}rperachse auch eine solche der ML Achse beitr{\"a}gt. In humanen malignen Tumoren sind der Wnt-, Slit-Robo- und Hh-Signalweg gut erforschte Wirkstofftargets und k{\"o}nnten in Zukunft in {\"a}hnlicher Weise f{\"u}r eine zielgerichtete Therapie von AE dienen.}, subject = {Fuchsbandwurm}, language = {de} } @article{HerzBrehm2019, author = {Herz, Michaela and Brehm, Klaus}, title = {Evidence for densovirus integrations into tapeworm genomes}, series = {Parasites \& Vectors}, volume = {12}, journal = {Parasites \& Vectors}, doi = {10.1186/s13071-019-3820-1}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-202478}, pages = {560}, year = {2019}, abstract = {Background Tapeworms lack a canonical piRNA-pathway, raising the question of how they can silence existing mobile genetic elements (MGE). Investigation towards the underlying mechanisms requires information on tapeworm transposons which is, however, presently scarce. Methods The presence of densovirus-related sequences in tapeworm genomes was studied by bioinformatic approaches. Available RNA-Seq datasets were mapped against the Echinococcus multilocularis genome to calculate expression levels of densovirus-related genes. Transcription of densovirus loci was further analyzed by sequencing and RT-qPCR. Results We herein provide evidence for the presence of densovirus-related elements in a variety of tapeworm genomes. In the high-quality genome of E. multilocularis we identified more than 20 individual densovirus integration loci which contain the information for non-structural and structural virus proteins. The majority of densovirus loci are present as head-to-tail concatemers in isolated repeat containing regions of the genome. In some cases, unique densovirus loci have integrated close to histone gene clusters. We show that some of the densovirus loci of E. multilocularis are actively transcribed, whereas the majority are transcriptionally silent. RT-qPCR data further indicate that densovirus expression mainly occurs in the E. multilocularis stem cell population, which probably forms the germline of this organism. Sequences similar to the non-structural densovirus genes present in E. multilocularis were also identified in the genomes of E. canadensis, E. granulosus, Hydatigera taeniaeformis, Hymenolepis diminuta, Hymenolepis microstoma, Hymenolepis nana, Taenia asiatica, Taenia multiceps, Taenia saginata and Taenia solium. Conclusions Our data indicate that densovirus integration has occurred in many tapeworm species. This is the first report on widespread integration of DNA viruses into cestode genomes. Since only few densovirus integration sites were transcriptionally active in E. multilocularis, our data are relevant for future studies into gene silencing mechanisms in tapeworms. Furthermore, they indicate that densovirus-based vectors might be suitable tools for genetic manipulation of cestodes.}, language = {en} } @phdthesis{Aldejohann2022, author = {Aldejohann, Alexander Maximilian}, title = {Echinocandin-Resistenzen in \(Candida\) \(glabrata\)}, doi = {10.25972/OPUS-27584}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-275840}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2022}, abstract = {Candida glabrata ist die zweith{\"a}ufigste Ursache von Candid{\"a}mien und invasiven Hefepilzinfektionen in Europa. Im Gegensatz zu C. albicans zeigt C. glabrata eine reduzierte Empfindlichkeit gegen bestimmte Antimykotika und kann unter Therapie rasch Resistenzen entwickeln. Diese Arbeit umfasst eine systematische geno- und ph{\"a}notypische Resistenzanalyse einer der gr{\"o}ßten europ{\"a}ischen - durch das NRZMyk in 5 Jahren zusammengetragenen - C. glabrata Stammsammlungen bestehend aus 176 klinisch relevanter Isolate. 84 der St{\"a}mme wurden anhand Referenztestung nach EUCAST zun{\"a}chst als Anidulafungin (AND) resistent eingestuft. 71 wiesen konkordante Mutationen in den f{\"u}r die Glucan-Synthetase kodierenden FKS-Genen auf (13 \% in FKS1, 87 \% in FKS2). Vor allem die Position Ser-663 (FKS2-HS1) imponierte mit signifikant erh{\"o}hten AND MHK-Werten. 11 FKS-Wildtyp-Isolate, die urspr{\"u}nglich als AND resistent klassifiziert wurden, wiesen in multiplen Nachtestungen um den Breakpoint undulierende AND MHK-Werte auf. 2 FKS-Wildtyp Isolate zeigten durchg{\"a}ngig hohe AND MHK-Werte und mussten daher - trotz fehlender Zielgenmutationen - als resistent eingestuft werden. Diese extremen Ph{\"a}notypen wurden durch einen verblindeten nationalen Ringversuch best{\"a}tigt. {\"U}ber ein Drittel der Isolate war multiresistent. St{\"a}mme aus Blutstrominfektionen und Ser-663 Mutation waren mit einer erh{\"o}hten Mortalit{\"a}t assoziiert. Ein weiteres Kernelement war die Detektion von Azol-resistenten C. glabrata petite-Ph{\"a}notypen in der Routinediagnostik. Hier wurden innerhalb von 8 Monaten 20 relevante Isolate identifiziert. Die Ergebnisse belegen das regelm{\"a}ßige Auftreten single- / multidrug-resistenter C. glabrata Isolate in Deutschland. Ph{\"a}notypische Resistenztestungen k{\"o}nnen zu Fehlklassifizierung von sensiblen Isolaten f{\"u}hren. FKS-Genotypisierungen hingegen sind ein n{\"u}tzliches Tool zur Identifizierung relevanter Resistenzen. In seltenen F{\"a}llen scheint jedoch eine Echinocandin-Resistenz ohne genotypisches Korrelat m{\"o}glich zu sein.}, subject = {Resistenzbestimmung}, language = {de} }