@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{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} } @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} } @phdthesis{Bauer2011, author = {Bauer, Ruth}, title = {Interaktionen von humanen Immuneffektorzellpopulationen mit dem humanpathogenen Pilz Aspergillus fumigatus, sowie der Einfluss von40-0-[2-Hydroxyethyl]rapamycin (RAD) auf deren Funktionen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-65499}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2011}, abstract = {Durch die Immunsuppression bei Patienten nach Stammzell- oder Organtransplantation erh{\"o}ht sich das Risiko f{\"u}r opportunistische Infektionen wie invasive Aspergillose (IA). IA wird haupts{\"a}chlich durch den Schimmelpilz Aspergillus fumigatus, der durch die Luft {\"u}bertragen wird, verursacht. Deshalb haben Erkennung und Therapie von IA in den letzten Jahren eine immer gr{\"o}ßere Bedeutung erlangt. F{\"u}r eine erfolgreiche Behandlung sind die Mechanismen des Immunsystems nach Kontaktaufnahme mit dem Pathogen von zentraler Bedeutung. Die Erstinfektion mit A. fumigatus findet in der Lunge statt. Als Bewohner der Alveolen wurden deshalb dendritische Zellen (DCs) auf ihre F{\"a}higkeiten hin untersucht, das Immunsystem anzuregen. DCs besitzen vor allem die wichtigen Aufgaben, das Immunsystem zu modulieren und T-Lymphozyten zur Proliferation anzuregen. Ein Großteil dieser Arbeit befasst sich mit der Analyse des Einflusses des Immunsuppressivums 40-0-[2-Hydroxyethyl]rapamycin (RAD) auf neutrophile Granulozyten und auf die in vitro Generierung von moDCs sowie deren F{\"a}higkeit mit dem Pathogen A. fumigatus zu interagieren. RAD bindet an das zytosolische FK506 bindende Protein (FKBP12), wodurch die Kinase mammalian target of rapamycin (mTOR) inhibiert und somit die T-Zellantwort unterdr{\"u}ckt wird. Klinische Anwendung findet RAD bereits, um eine Immunsuppression bei Patienten nach Stammzell- oder Organtransplantation zu erhalten. Der oxidative Burst neutrophiler Granulozyten war nach RAD-Behandlung und Konfrontation mit A. fumigatus signifikant verringert. Die Generierung der moDCs aus Monozyten erfolgte {\"u}ber 7 Tage, wobei ab dem Tag der Isolation der Monozyten 10 nM RAD oder EtOH zur Kontrolle hinzugegeben wurde. RAD zeigte vielf{\"a}ltige Effekte auf die Immunfunktion dendritischer Zellen. Obwohl sich keine {\"A}nderung in der Differenzierung der moDCs fand, was durch die Oberfl{\"a}chenmarker CD1a+, CD14- und HLA-DR+ {\"u}berpr{\"u}ft wurde, zeigte sich eine signifikante Reduktion der Rezeptoren TLR4 und Dectin-1 sowie der kostimulatorischen Molek{\"u}le CD40, CD83 und CD86. Nach Konfrontation mit A. fumigatus verblieb CD40 unter RAD Behandlung signifikant reduziert, w{\"a}hrend CD83 genau dieses Schema als Trend aufwies. Ferner wies CD86 sowohl in der Kontrolle als auch mit RAD-Behandlung die gleiche Expression auf. Nach 6 h Konfrontation der moDCs mit A. fumigatus waren die Zytokine IL-12, TNF-α und CCL20 auf Genexpressionsebene unter RAD reduziert, was sich auf Proteinebene teilweise best{\"a}tigen ließ, da sich hier erst nach 12 h eine signifikante Reduktion von IL-12, TNF-α und CCL20 in RAD-behandelten Zellen im Vergleich zu Kontrollzellen zeigte. Des Weiteren war das anti-inflammatorische Zytokin IL-10 signifikant reduziert. Die Phagozytose sowohl von FITC-Dextran-Beads als auch von A. fumigatus Konidien und zugleich die Sch{\"a}digung von A. fumigatus Keimschl{\"a}uchen war in unreifen RAD-behandelten moDCs signifikant reduziert. Ob moDCs, die mit RAD behandelt wurden, schlechter in der Lage waren, CD8+-T-Lymphozyten zur Proliferation anzuregen, geht nicht mit Sicherheit aus dieser Studie hervor, da große spenderabh{\"a}ngige Unterschiede auftraten. Es wurde zudem ein Vergleich von in vitro aus Monozyten differenzierten DCs (moDCs) und myeloiden DCs (mDCs) angefertigt. Mittels eines home-made Microarrays, der vor allem Gene mit einschloss, die f{\"u}r Zytokine und Rezeptoren von Immunzellen kodieren, konnten in einem Modell der fr{\"u}hen IA in der Lunge differentiell regulierte Gene nach Konfrontation mit A. fumigatus identifiziert werden. Es wurden insgesamt 30 Gene mehr als 2-fach reguliert, wie zum Beispiel die Interleukine und Chemokine IL-1β, IL-8, CXCL2, CCL3, CCL4 und CCL20, der Immunrezeptor PTX3 und der Transkriptionsfaktor Nf-κB. Generell konnte beobachtet werden, dass moDCs mehr regulierte Gene aufwiesen als mDCs. Zuletzt wurde betrachtet, ob der Knock-down von CXCL10, dessen Fehlen ein erh{\"o}htes Risiko f{\"u}r IA nach sich zieht, einen Einfluss auf moDCs hat, so dass sie schlechter auf A. fumigatus reagieren k{\"o}nnen. Diese Hypothese konnte in dieser Studie nicht best{\"a}tigt werden, da kein Unterschied in der Zytokinproduktion oder Expression kostimulatorischer Molek{\"u}le zwischen Kontroll-moDCs und moDCs, in denen das CXCL10-Gen ausgeschaltet wurde, festgestellt werden konnte. Zusammenfassend l{\"a}sst sich sagen, dass durch die Microarray-Analyse wichtige Gene in moDCs und mDCs identifizierbar waren, die nach Konfrontation mit A. fumigatus reguliert wurden. Zudem fanden sich lediglich minimale Unterschiede zwischen artifiziellen DCs und myeloiden DCs, die direkt aus dem K{\"o}rper isoliert wurden. Eine Behandlung mit RAD erh{\"o}ht das Risiko eines Patienten an invasiver Aspergillose zu erkranken unabh{\"a}ngig von der Eigenschaft des RAD, die Proliferation von T-Lymphozyten zu inhibieren.}, subject = {Aspergillus fumigatus}, language = {de} } @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{BarthHerrmannTappeetal.2012, author = {Barth, Thomas F. E. and Herrmann, Tobias S. and Tappe, Dennis and Stark, Lorenz and Gr{\"u}ner, Beate and Buttenschoen, Klaus and Hillenbrand, Andreas and Juchems, Markus and Henne-Bruns, Doris and Kern, Petra and Seitz, Hanns M. and M{\"o}ller, Peter and Rausch, Robert L. and Kern, Peter and Deplazes, Peter}, title = {Sensitive and Specific Immunohistochemical Diagnosis of Human Alveolar Echinococcosis with the Monoclonal Antibody Em2G11}, series = {PLoS Neglected Tropical Diseases}, volume = {6}, journal = {PLoS Neglected Tropical Diseases}, number = {10}, doi = {10.1371/journal.pntd.0001877}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-135371}, pages = {e1877}, year = {2012}, abstract = {Background: Alveolar echinococcosis (AE) is caused by the metacestode stage of Echinococcus multilocularis. Differential diagnosis with cystic echinococcosis (CE) caused by E. granulosus and AE is challenging. We aimed at improving diagnosis of AE on paraffin sections of infected human tissue by immunohistochemical testing of a specific antibody. Methodology/Principal Findings: We have analysed 96 paraffin archived specimens, including 6 cutting needle biopsies and 3 fine needle aspirates, from patients with suspected AE or CE with the monoclonal antibody (mAb) Em2G11 specific for the Em2 antigen of E. multilocularis metacestodes. In human tissue, staining with mAb Em2G11 is highly specific for E. multilocularis metacestodes while no staining is detected in CE lesions. In addition, the antibody detects small particles of E. multilocularis (spems) of less than 1 mm outside the main lesion in necrotic tissue, liver sinusoids and lymphatic tissue most probably caused by shedding of parasitic material. The conventional histological diagnosis based on haematoxylin and eosin and PAS stainings were in accordance with the immunohistological diagnosis using mAb Em2G11 in 90 of 96 samples. In 6 samples conventional subtype diagnosis of echinococcosis had to be adjusted when revised by immunohistology with mAb Em2G11. Conclusions/Significance: Immunohistochemistry with the mAb Em2G11 is a new, highly specific and sensitive diagnostic tool for AE. The staining of small particles of E. multilocularis (spems) outside the main lesion including immunocompetent tissue, such as lymph nodes, suggests a systemic effect on the host.}, language = {en} } @phdthesis{Aumann2018, author = {Aumann, Ralf}, title = {Vorkommen und Expression des opcA Gens in Meningokokkenst{\"a}mmen von Erkrankten und asymptomatischen Tr{\"a}gern}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-157278}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2018}, abstract = {Das Opc-Protein ist ein Außenmembranprotein von Meningokokken, das {\"u}ber extrazellul{\"a}re Matrixproteine mit Integrinen der Wirtszelle interagiert. Opc ist in Menschen immunogen und induziert bakterizide Antik{\"o}rper. Das Opc-Protein wurde daher als aussichtsreicher Impfstoff-Kandidat angesehen, da es außerdem relativ gut konserviert ist. Allerdings wird das Opc-Protein nicht von allen Meningokokkenst{\"a}mmen exprimiert. Einerseits fehlt das opc-Gen in einigen klonalen Komplexen (z.B. ST-8, ST-11, ST-53), andererseits ist die Opc-Expression nicht konstitutiv wegen einer phasenvariablen Transkription, die auf einem Poly-Cytidin-Bereich im Promotor des opc-Gens beruht. In dieser Arbeit wurde die Pr{\"a}senz des opc-Gens und die Opc-Expression in zwei großen Sammlungen deutscher Meningokokkenisolate von invasiven Erkrankungen (n=1141) und gesunden Tr{\"a}gern (n=792) untersucht. Das opc-Gen war bei 71\% der invasiven und 77\% der Tr{\"a}gerst{\"a}mme nachweisbar. Der gr{\"o}ßte Teil der opc-Gen negativen St{\"a}mme geh{\"o}rte zu den klonalen Komplexen ST-8, ST-11, ST-213, ST-231, ST-334 und ST-53. Der Anteil opc-positiver St{\"a}mme, die Opc in vitro exprimieren, war bei den invasiven St{\"a}mmen kleiner als bei den Tr{\"a}gerst{\"a}mmen (13\% vs. 29\%, p<0,001, Chi-square-Test). Der gr{\"o}ßere Anteil Opc-exprimierender Tr{\"a}gerst{\"a}mme ist u.a. am ehesten mit der {\"U}berrepr{\"a}sentation von wenig pathogenen klonalen Komplexen (ST-23, ST-35, ST-198) mit einer hohen Opc-Expressionsrate zu erkl{\"a}ren. 24 von den 176 invasiven St{\"a}mmen mit einer Anzahl von 11 - 14 Cs in der Promotor-Region, die die Opc-Expression beg{\"u}nstigt, zeigten weder im ELISA noch im Westernblot eine Opc-Expression. Bei 14 dieser 24 St{\"a}mme wurde als Ursache ein phasenvariabler, intragenischer Poly-Adenin-Bereich identifiziert, der zu einer Leserasterverschiebung f{\"u}hrte. Die Vermutung mehrerer Autoren, dass die Opc-Expression mit dem klinischen Bild der Meningitis verkn{\"u}pft ist, konnte mit der hier genutzten großen Stammsammlung nicht best{\"a}tigt werden. Invasive St{\"a}mme, die das Opc-Protein exprimierten, wurden genauso h{\"a}ufig von Patienten mit dem klinischen Bild der Meningitis isoliert wie St{\"a}mme, die das Opc-Protein nicht exprimierten (46\% vs. 47\%, Chi-square-Test: p<0,9). Allerdings gibt es eine starke Assoziation der Gegenwart des opc-Gens mit dem klinischen Merkmal Meningitis. Dieser Befund gibt Anlass zu der Hypothese, dass in vitro und in vivo Expression von Opc sich unterscheiden. Zusammenfassend l{\"a}sst sich festhalten, dass das Opc-Protein nur in 19,8\% aller Isolate (invasive und Tr{\"a}gerst{\"a}mme zusammengenommen) exprimiert wurde. Es zeigte sich eine Tendenz zu h{\"a}ufigerer Opc-Expression in apathogenen Tr{\"a}gerisolaten. Das Vorhandensein des opc-Gens, nicht aber die in vitro Expression konnten mit dem klinischen Merkmal Meningitis assoziiert werden. Zus{\"a}tzlich wurde ein weiterer Mechanismus der intragenischen Phasenvariation beschrieben.}, subject = {Neisseria meningitidis}, language = {de} } @article{AtanasovBenkertThelenetal.2013, author = {Atanasov, Georgi and Benkert, Christoph and Thelen, Armin and Tappe, Dennis and Frosch, Matthias and Teichmann, Dieter and Barth, Thomas F. E. and Wittekind, Christian and Schubert, Stefan and Jonas, Sven}, title = {Alveolar echinococcosis-spreading disease challenging clinicians: A case report and literature review}, series = {World Journal of Gastroenterology}, volume = {19}, journal = {World Journal of Gastroenterology}, number = {26}, doi = {10.3748/wjg.v19.i26.4257}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-131525}, pages = {4257-4261}, year = {2013}, abstract = {Human alveolar echinococcosis (AE) is a potentially deadly disease; recent studies have shown that the endemic area of Echinococcus multilocularis, its causative agent, is larger than previously known. This disease has low prevalence and remains underreported in Europe. Emerging clinical data show that diagnostic difficulties are still common. We report on a 76-year old patient suffering from AE lesions restricted to the left lobe of the liver who underwent a curative extended left hemihepatectomy. Prior to the resection a liver biopsy under the suspicion of an atypical malignancy was performed. After the intervention he developed a pseudoaneurysm of the hepatic artery that was successfully coiled. Surprisingly, during surgery, the macroscopic appearance of the tumour revealed a growth pattern that was rather typical for cystic echinococcosis (CE), i.e., a gross tumour composed of multiple large vesicles with several centimeters in diameter. In addition, there were neither extensive adhesions nor infiltrations of the neighboring pancreas and diaphragm as was expected from previous imaging results. The unexpected diagnosis of AE was confirmed by definite histopathology, specific polymerase chain reaction and serology results. This is a rare case of unusual macroscopic presentation of AE that posed immense diagnostic challenges and had an eventful course. To our knowledge this is the first case of an autochthonous infection in this particular geographic area of Germany, the federal state of Saxony. This report may provide new hints for an expanding area of risk for AE and emphasizes the risk of complications in the scope of diagnostic procedures and the limitations of modern radiological imaging.}, 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{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{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} } @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} } @article{AlZabenMedyukhinaDietrichetal.2019, author = {Al-Zaben, Naim and Medyukhina, Anna and Dietrich, Stefanie and Marolda, Alessandra and H{\"u}nniger, Kerstin and Kurzai, Oliver and Figge, Marc Thilo}, title = {Automated tracking of label-free cells with enhanced recognition of whole tracks}, series = {Scientific Reports}, volume = {9}, journal = {Scientific Reports}, doi = {10.1038/s41598-019-39725-x}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-221093}, year = {2019}, abstract = {Migration and interactions of immune cells are routinely studied by time-lapse microscopy of in vitro migration and confrontation assays. To objectively quantify the dynamic behavior of cells, software tools for automated cell tracking can be applied. However, many existing tracking algorithms recognize only rather short fragments of a whole cell track and rely on cell staining to enhance cell segmentation. While our previously developed segmentation approach enables tracking of label-free cells, it still suffers from frequently recognizing only short track fragments. In this study, we identify sources of track fragmentation and provide solutions to obtain longer cell tracks. This is achieved by improving the detection of low-contrast cells and by optimizing the value of the gap size parameter, which defines the number of missing cell positions between track fragments that is accepted for still connecting them into one track. We find that the enhanced track recognition increases the average length of cell tracks up to 2.2-fold. Recognizing cell tracks as a whole will enable studying and quantifying more complex patterns of cell behavior, e.g. switches in migration mode or dependence of the phagocytosis efficiency on the number and type of preceding interactions. Such quantitative analyses will improve our understanding of how immune cells interact and function in health and disease.}, language = {en} } @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{Abele2002, author = {Abele, Tobias}, title = {Invasion, Replikation und Stadienkonversion von Toxoplasma gondii in permanenten ZNS-Zelllinien der Ratte}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-4521}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2002}, abstract = {Permanente ZNS-Zelllinien der Ratte wurden mit Toxoplasma gondii unter Betrachtung der Invasions-, Replikations- und Stadienkonversionf{\"a}higeit des Parasiten infiziert. Additiv zu bekannten Tiermodellen konnte so ein Zellkulturmodell zur Erforschung der zerebralen Persistenz des Protozoons etabliert werden.}, language = {de} } @phdthesis{Abele2009, author = {Abele, Marion}, title = {Die Bedeutung des Zwei-Partner-Sekretionssystems f{\"u}r die Adh{\"a}renz von Meningokokken an Epithelzellen}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-45369}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2009}, abstract = {Das two-partner secretion-system (TPS-System) ist ein unter Gram-negativen Bakterien weit verbreiteter Weg der Proteinsekretion. Die als TpsA bezeichneten Exoproteine des TPS Systems ben{\"o}tigen ein spezifisches Partnerprotein (genannt TpsB) in Form eines kanalbildenden Transporters. Im sequenzierten Genom des Meningokokkenstammes MC58 finden sich f{\"u}nf putative tpsA Gene, die als hemagglutinin/hemolysin-related protein (hrps) bezeichnete werden. Neben MC58 finden sich auch in den anderen sequenzierten Meningokokkenst{\"a}mmen (FAM18, Z2491, alpha14) hrps. Diese weisen N-terminal Homologien zum filament{\"o}sen H{\"a}magglutinin (FHA) von B. pertussis auf, das als TpsA-Protein des two-partner-secretion-system (TPS) aus der Zelle transportiert wird. In dieser Arbeit werden die hrps als hrpA Gene bzw. HrpA-Proteine bezeichnet. Alle sequenzierten Meningokokkenst{\"a}mme verf{\"u}gen {\"u}ber tpsB homologe Gene (hrpB), die jeweils in enger Nachbarschaft zu den hrpA Genen zu finden sind. Das Vorhandensein von hrpA und hrpB Genen deutet darauf hin, dass auch Meningokokken {\"u}ber ein funktionales TPS-System verf{\"u}gen. Bei einer Dot-Blot-Analyse von 830 Meningokokkenst{\"a}mmen aus einer bayerischen Tr{\"a}gerstudie mit Sonden spezifisch f{\"u}r die C-terminalen Bereiche der im Stamm MC58 gefundenen hrpA Gene hybridisierten 80\% der ausgewerteten St{\"a}mme mit mindestens einer der Sonden. St{\"a}mme der hypervirulenten klonalen Komplexen (ST-8, ST-11, ST32, ST-44) zeigten sogar in {\"u}ber 99\% eine positive Reaktion. Dagegen wiesen die nicht-hypervirulenten klonalen Komplexe zu 29\% im Dot Blot kein hrpA auf, das homolog zu den hrpA Genen von Stamm MC58 ist, wobei es sich hierbei mehrheitlich (82\%) um cnl St{\"a}mme handelte, so dass sich nur in 10\% der untersuchten Kapsel-null-locus-St{\"a}mme (cnl) ein zu den hrpA Genen von MC58 homologes Gen nachweisen ließ. Mit der Hypothese, dass auch diese St{\"a}mme ein hrpA besitzen, welches sich im C-terimalen Anteil von denen des MC58 unterscheidet wurden in dieser Arbeit Dot Blots durchgef{\"u}hrt, deren Sonde spezifisch f{\"u}r das hrpB NMC0443 war. 97,6\% der mit dieser Sonde untersuchten St{\"a}mme zeigten die Anwesenheit eines hrpB Homologs. Um die Vermutung zu best{\"a}tigen, dass allen hrpB Genen ein zugeh{\"o}riges hrpA Gen benachbart liegt, wurden repr{\"a}sentativ PCRs von h{\"a}ufigen klonalen Komplexen durchgef{\"u}hrt. Dabei konnte gezeigt werden, dass ein TPS-System sowohl in den hypervirulenten als auch den nicht-hypervirulenten klonalen Komplexen der Meningokokken vorkommt. Die vielf{\"a}ltigen Funktionen von bereits untersuchten TpsA Proteinen sind zumeist mit der Pathogenit{\"a}t der Bakterien assoziiert. In dieser Arbeit wurde ein m{\"o}glicher Einfluss der HrpA Proteine auf die Adh{\"a}sion der Bakterien an humane Zellen untersucht. Es konnte gezeigt werden, dass sowohl eine kapsellose, als auch eine kapsellose, LPS-trunkierte hrpA Deletionsmutante signifikant schlechter an Epithelzellen adh{\"a}riert als die parentalen Vergleichsst{\"a}mme. Ebenso zeigten die analog durchgef{\"u}hrten Infektionsversuche mit der hrpB Deletionsmutante einen Adh{\"a}renzverlust, der jedoch nur f{\"u}r die unbekapselte und LPS trunkierte hrpB Deletionsmutante signifikant war. In dieser Arbeit ist es gelungen das HrpB Protein des Stammes 2120 in E. coli zu exprimieren und aufzureinigen, sodass die Entwicklung eines gegen HrpB gerichteten Antik{\"o}rpers in Auftrag gegeben werden konnte. Mit Hilfe dieses Antik{\"o}rpers sollen noch offene Fragen zur Synthese und dem Transport des HrpB Transportproteins beantwortet werden. Außerdem k{\"o}nnen weitere Untersuchungen zur Lage und Verteilung der HrpBs in der Meningokokkenmembran dazu beitragen, weiteren Aufschluss {\"u}ber die Komplexit{\"a}t von Pathogenit{\"a}t und Virulenz von N. meningitidis zu geben.}, subject = {W{\"u}rzburg / Institut f{\"u}r Hygiene und Mikrobiologie}, language = {de} }