TY - JOUR A1 - Aldejohann, Alexander Maximilian A1 - Wiese-Posselt, Miriam A1 - Gastmeier, Petra A1 - Kurzai, Oliver T1 - Expert recommendations for prevention and management of Candida auris transmission JF - Mycoses N2 - 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. KW - Candida auris KW - nosocomial transmission KW - infection prevention KW - expert recommendation Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-318570 VL - 65 IS - 6 SP - 590 EP - 598 ER - TY - JOUR A1 - Walther, Grit A1 - Zimmermann, Anna A1 - Theuersbacher, Johanna A1 - Kaerger, Kerstin A1 - Lilienfeld-Toal, Marie von A1 - Roth, Mathias A1 - Kampik, Daniel A1 - Geerling, Gerd A1 - Kurzai, Oliver T1 - Eye infections caused by filamentous fungi: spectrum and antifungal susceptibility of the prevailing agents in Germany JF - Journal of Fungi N2 - 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. KW - eye infection KW - fungal infection KW - keratitis KW - antifungal susceptibility KW - natamycin KW - Fusarium KW - Purpureocillium KW - Aspergillus KW - Alternaria KW - Scedosporium Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-241810 SN - 2309-608X VL - 7 IS - 7 ER - TY - JOUR A1 - Moremi, Nyambura A1 - Claus, Heike A1 - Vogel, Ulrich A1 - Mshana, Stephen E. T1 - Faecal carriage of CTX-M extended-spectrum beta-lactamase-producing Enterobacteriaceae among street children dwelling in Mwanza city, Tanzania JF - PLoS ONE N2 - 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. KW - Tanzania KW - children KW - Enterobacteriaceae KW - ESBL Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170331 VL - 12 IS - 9 ER - TY - JOUR A1 - Soundararajan, Manonmani A1 - Marincola, Gabriella A1 - Liong, Olivia A1 - Marciniak, Tessa A1 - Wencker, Freya D. R. A1 - Hofmann, Franka A1 - Schollenbruch, Hannah A1 - Kobusch, Iris A1 - Linnemann, Sabrina A1 - Wolf, Silver A. A1 - Helal, Mustafa A1 - Semmler, Torsten A1 - Walther, Birgit A1 - Schoen, Christoph A1 - Nyasinga, Justin A1 - Revathi, Gunturu A1 - Boelhauve, Marc A1 - Ziebuhr, Wilma T1 - Farming practice influences antimicrobial resistance burden of non-aureus staphylococci in pig husbandries JF - Microorganisms N2 - Non-aureus staphylococci (NAS) are ubiquitous bacteria in livestock-associated environments where they may act as reservoirs of antimicrobial resistance (AMR) genes for pathogens such as Staphylococcus aureus. Here, we tested whether housing conditions in pig farms could influence the overall AMR-NAS burden. Two hundred and forty porcine commensal and environmental NAS isolates from three different farm types (conventional, alternative, and organic) were tested for phenotypic antimicrobial susceptibility and subjected to whole genome sequencing. Genomic data were analysed regarding species identity and AMR gene carriage. Seventeen different NAS species were identified across all farm types. In contrast to conventional farms, no AMR genes were detectable towards methicillin, aminoglycosides, and phenicols in organic farms. Additionally, AMR genes to macrolides and tetracycline were rare among NAS in organic farms, while such genes were common in conventional husbandries. No differences in AMR detection existed between farm types regarding fosfomycin, lincosamides, fusidic acid, and heavy metal resistance gene presence. The combined data show that husbandry conditions influence the occurrence of resistant and multidrug-resistant bacteria in livestock, suggesting that changing husbandry practices may be an appropriate means of limiting the spread of AMR bacteria on farms. KW - non-aureus staphylococci KW - NAS KW - alternative pig farming KW - antimicrobial resistance KW - one-health approach KW - intervention strategies KW - livestock-associated staphylococci KW - organic farming KW - pig farming methods Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312750 SN - 2076-2607 VL - 11 IS - 1 ER - TY - THES A1 - Schielke, Stephanie T1 - Functional and molecular characterization of FarR – a transcriptional regulator of the MarR family in Neisseria meningitidis T1 - Funktionelle und molekulare Charakterisierung von FarR, einem Transkriptionsregulator der MarR Familie in Neisseria meningitidis N2 - Neisseria meningitidis is a facultatively pathogenic human commensal and strictly adapted to its niche within the human host, the nasopharynx. Not much is known about the regulatory processes required for adaptation to this environment. Therefore the role of the transcriptional regulator NMB1843, one of the two predicted regulators of the MarR family in the meningococcal genome, was investigated. As this gene displayed a high sequence homology to FarR, the Fatty acid resistance Regulator in N. gonorrhoeae, we designated the meningococcal protein FarR (NmFarR). Homology modeling of this protein revealed a dimeric structure with the characteristic winged helix-turn-helix DNA binding motif of the MarR family. NmFarR is highly conserved among meningococcal strains and expression of farR during exponential growth is controlled post-transcriptionally, being highest in the late exponential phase. By means of electrophoretic mobility shift assays (EMSAs) the direct and specific binding of FarR to the farAB promoter region was shown, comparable to its homologue in gonococci. As FarR is involved in fatty acid resistance in N. gonorrhoeae, susceptibility assays with the medium chain lauric acid (C12:0), the long chain saturated palmitic acid (C16:0) and the long chain unsaturated linoleic acid (C18:2) were performed, testing a wide variety of strains of both species. In contrast to the unusually susceptible gonococci, a high intrinsic fatty acid resistance was detected in almost all meningococcal isolates. The molecular basis for this intrinsic resistance in N. meningitidis was elucidated, showing that both a functional FarAB efflux pump system as well as an intact lipopolysaccharide (LPS) are responsible for palmitic acid resistance. However, even despite circumvention of the intrinsic resistance, FarR could not be connected with fatty acid resistance in meningococci. Instead, FarR was shown to directly and specifically repress expression of the Neisseria adhesin A (nadA), a promising vaccine candidate absent in N. gonorrhoeae. Microarray analyses verified these results and disclosed no further similarly regulated genes, rendering the FarR regulon the smallest regulon in meningococci reported until now. The exact FarR binding site within the nadA promoter region was identified as a 16 bp palindromic repeat and its influence on nadA transcription was proved by reporter gene fusion assays. This repression was also shown to be relevant for infection as farR deficient mutant strains displayed an increased attachment to epithelial cells. Furthermore, farR transcription was attested to be repressed upon contact with active complement components within human serum. Concluding, it is shown that FarR adopted a role in meningococcal host niche adaptation, holding the balance between immune evasion by repressing the highly antigenic nadA and host cell attachment via this same adhesin. N2 - Neisseria meningitidis ist ein fakultativ pathogener menschlicher Kommensale und eng an die Bedingungen seiner spezifischen Nische, den Nasopharynx, angepasst. Über die regulatorischen Mechanismen, die für diese Anpassung vonnöten sind, ist nicht viel bekannt. Daher wurde die Rolle des Transkriptionsregulators NMB1843 untersucht, eines der beiden prognostizierten Regulatoren der MarR Familie im Meningokokken-Genom. Aufgrund einer hohen Sequenzhomologie dieses Gens zu FarR, dem Fatty acid resistance Regulator in N. gonorrhoeae, nannten wir das Meningokokken-Protein ebenfalls FarR (NmFarR). Homologie-Modellierung dieses Proteins ergab eine dimere Struktur mit dem charakteristischen winged helix-turn-helix DNA-Bindemotiv der MarR Familie. Es wurde gezeigt, dass NmFarR in Meningokokken-Stämmen hochkonserviert ist. Die Expression von farR wird während des exponentiellen Wachstums posttranskriptional kontrolliert und erreicht ihren Höchststand in der spätexponentiellen Phase. Wie bei seinem Homolog in Gonokokken konnte die direkte und spezifische Bindung von FarR an die farAB Promotorregion nachgewiesen werden. Da FarR in N. gonorrhoeae an der Fettsäureresistenz beteiligt ist, wurde die Suszeptibilität einer großen Auswahl von Stämmen beider Spezies gegenüber drei unterschiedlichen Fettsäuren getestet: Laurinsäure (C12:0), Palmitinsäure (C16:0) und Linolsäure (C18:2). Im Gegensatz zu den ungewöhnlich sensitiven Gonokokken konnte eine hohe inhärente Fettsäureresistenz in fast allen Meningokokken-Isolaten beobachtet werden. Nach Analyse der molekularen Grundlage dieser Resistenz konnte gezeigt werden, dass sowohl eine funktionale FarAB Efflux-Pumpe als auch ein intaktes Lipopolysaccharid (LPS) für die Palmitinsäureresistenz verantwortlich sind. Trotz Umgehung der inhärenten Resistenz konnte keine Verbindung von FarR mit Fettsäureresistenz in Meningokokken hergestellt werden. Stattdessen reprimiert FarR direkt und spezifisch die Expression des Neisseria Adhäsins A (nadA), eines vielversprechenden Impfstoffbestandteils. Microarrays bestätigten diese Ergebnisse, zeigten aber keine weiteren ähnlich regulierten Gene auf. Somit ist das FarR-Regulon das bisher kleinste Regulon in Meningokokken. Die genaue FarR-Bindestelle innerhalb des nadA Promotors wurde als ein 16 bp Palindrom identifiziert und dessen Einfluss auf die Transkription von nadA mittels Reportergenanalysen gezeigt. Auch in Infektionsversuchen wurde die Relevanz dieser Repression deutlich, da ein farR-deletierter Stamm eine höhere Adhärenz an Epithelzellen aufwies. Die Transkription von farR sank nach Kontakt mit aktiven Komplementbestandteilen aus humanem Serum. Zusammenfassend wurde gezeigt, dass FarR eine Rolle in der Nischenadaptation von Meningokokken zukommt, indem er zwischen Immunevasion durch Repression des hoch-immunogenen nadA und Wirtszelladhäsion durch eben dieses Adhäsin vermittelt. KW - Transkription KW - Neisseria gonorrhoeae KW - Neisseria meningitidis KW - Adhäsine KW - FarR KW - Transkriptionsregulation KW - NadA KW - Neisseria meningitdis KW - transcriptional regulation KW - FarR KW - Neisseria gonorrhoeae KW - niche adaptation Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48550 ER - TY - THES A1 - Pawlik, Marie-Christin T1 - Gene expression in the human pathogen Neisseria meningitidis: Adaptation to serum exposure and zinc limitation T1 - Genexpression im humanen Pathogen Neisseria meningitidis: Adaptation an Serumexposition und Zinkmangel N2 - 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. N2 - Neisseria meningitidis ist ein fakultatives Humanpathogen, welches mitunter sehr resistant gegenüber Serumkomplement-Exposition ist. Bereits beschriebene Faktoren, welche die Serumresistenz von Meningokokken fördern, sind beispielsweise die Kapsel, LPS-Sialylierung und Expression des fH-bindenden Proteins. Das Ziel dieser Arbeit war die Identifikation neuartiger Serumresistenzfaktoren, wobei ich zwei Ansätzen verfolgte: i) Die Analyse des Einflusses von globalen Regulatoren der Genexpression auf die Serumresistenz; und ii) eine vergleichenden Analyse von eng verwandten Stämmen, die sich hinsichtlich ihrer Serumresistanz unterschieden. i) Von sechs untersuchten globalen Regulatoren der Genexpression, war die Komplementdeposition auf Meningokokken nur nach Mutation des Regulators der Zinkaufnahme, Zur, reduziert. Über Zur selbst und die regulatorischen Prozesse in Reaktion auf Zink war in Meningokokken wenig bekannt. Ich habe daher das bisher nicht bestimmte Zur-Regulon von Meningokokken aufgeklärt, wofür ich mittels Mikroarrays die transkriptionelle Antwort des N. meningitidis-Stammes MC58 unter Zink-Überfluss und Zink-Mangel zu vergleichen. Das Zur-Regulon von Meningokokken umfasst 17 Gene, von denen unter Zinküberfluss 15 reprimiert und zwei aktiviert wurden. Unter den Zur-reprimierten Genen fanden sich Gene, die in die Aufnahme von Zink, die Modikation von tRNAs und den Zusammenbau des Ribosoms involviert sind. Ein 23 bp langes Binde-Konsensusmotiv für Meningokokken-Zur (Zur-Box) mit einem konservierten zentralen Palindrom wurde ermittelt (TGTTATDNHATAACA) und in der Promotorregion aller regulierten Transkriptionseinheiten (Gene/Operons) detektiert. In vitro-Bindung des N. meningitidis Zur an die Zur-Box dreier ausgewählter Genen konnte mittels EMSAs erstmals gezeigt werden. Die Bindung von Zur an DNA war spezifisch abhängig von Zink, und Mutationen in der palindromischen Sequenz hemmten die Zur-Bindung an das DNA-Motiv. ii) Drei eng verwandte Stämme des ST-41/44-Komplexes aus invasiver Erkrankung und Trägertum, die sich in ihrer Resistenz gegenüber Serumkomplement-Exposition unterschieden, wurden analysiert um neuartige Mediatoren der Serumresistenz zu identifizieren. Der Gengehalt der Stämme wurde mittels Mikroarray-Analyse verglichen. Dies offenbarte sechs Gene, die in den beiden Trägerstämmen vorhanden, aber in dem invasiven Isolat abwesend waren. Vier dieser Gene liegen innerhalb zweier Inseln horizontal transferierter DNA, d.h. IHT-B und –C. Weiterhin führte die Arbeitsgruppe eine Transkriptom- und Proteom-Analyse der drei Stämme sowie einen umfangsreichen Screening-Assay durch. Diese Ansätze führten zur Identifikation dreier Kandidaten-Proteine für die weitere Analyse. Ich wirkte daran mit, die Rolle dieser Proteine für die Serumresistenz von Meningokokken zu ermitteln: Das Adhäsin Opc vermittelt Serumresistenz durch Bindung von Vitronektin, einem negativen Regulator des Komplementsystems; das hypothetische Protein NMB0865 trägt über einen bisher unbekannten Mechanismus geringfügig zur Serumresistanz bei; und NspA, für welches vor Kurzem erkannt wurde, dass es den negativen Komplementregulator Faktor H bindet, führte zu beträchtlich reduzierter Abtötung durch Komplement. KW - Komplement KW - Neisseria meningitidis KW - Genregulation KW - Zinkmangel KW - Serumresistenz KW - Meningokokken KW - globale Regulatoren KW - Serum KW - Bakterien KW - Zink KW - serum resistance KW - meningococci KW - global regulators KW - zinc limitation Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-78758 ER - TY - THES A1 - Herz, Michaela T1 - Genome wide expression profiling of Echinococcus multilocularis T1 - Genomweite Expressionsanalysen von Echinococcus multilocularis N2 - Alveolar echinococcosis, which is caused by the metacestode stage of the small fox tapeworm Echinococcus multilocularis, is a severe zoonotic disease with limited treatment options. For a better understanding of cestode biology the genome of E. multilocularis, together with other cestode genomes, was sequenced previously. While a few studies were undertaken to explore the E. multilocularis transcriptome, a comprehensive exploration of global transcription profiles throughout life cycle stages is lacking. This work represents the so far most comprehensive analysis of the E. multilocularis transcriptome. Using RNA-Seq information from different life cycle stages and experimental conditions in three biological replicates, transcriptional differences were qualitatively and quantitatively explored. The analyzed datasets are based on samples of metacestodes cultivated under aerobic and anaerobic conditions as well as metacestodes obtained directly from infected jirds. Other samples are stem cell cultures at three different time points of development as well as non-activated and activated protoscoleces, the larval stage that can develop into adult worms. In addition, two datasets of metacestodes under experimental conditions suitable for the detection of genes that are expressed in stem cells, the so-called germinative cells, and one dataset from a siRNA experiment were analyzed. Analysis of these datasets led to expression profiles for all annotated genes, including genes that are expressed in the tegument of metacestodes and play a role in host-parasite interactions and modulation of the host's immune response. Gene expression profiles provide also further information about genes that might be responsible for the infiltrative growth of the parasite in the liver. Furthermore, germinative cell-specific genes were identified. Germinative cells are the only proliferating cells in E. multilocularis and therefore of utmost importance for the development and growth of the parasite. Using a combination of germinative cell depletion and enrichment methods, genes with specific expression in germinative cells were identified. As expected, many of these genes are involved in translation, cell cycle regulation or DNA replication and repair. Also identified were transcription factors, many of which are involved in cell fate commitment. As an example, the gene encoding the telomerase reverse transcriptase (TERT) was studied further. Expression of E. multilocularis tert in germinative cells was confirmed experimentally. Cell culture experiments indicate that TERT is required for proliferation and development of the parasite, which makes TERT a potentially interesting drug target for chemotherapy of alveolar echinococcosis. Germinative cell specific genes in E. multilocularis also include genes of densoviral origin. More than 20 individual densovirus loci with information for non-structural and structural densovirus proteins were identified in the E. multilocularis genome. Densoviral elements were also detected in many other cestode genomes. Genomic integration of these elements suggests that densovirus-based vectors might be suitable tools for genetic manipulation of tapeworms. Interestingly, only three of more than 20 densovirus loci in the E. multilocularis genome are expressed. Since the canonical piRNA pathway is lacking in cestodes, this raises the question about potential silencing mechanisms. Exploration of RNA-Seq information indicated natural antisense transcripts as a potential gene regulation mechanism in E. multilocularis. Preliminary experiments further suggest DNA-methylation, which was previously shown to occur in platyhelminthes, as an interesting avenue to explore in future. The transcriptome datasets also contain information about genes that are expressed in differentiated cells, for example the serotonin transporter gene that is expressed in nerve cells. Cell culture experiments indicate that serotonin and serotonin transport play an important role in E. multilocularis proliferation, development and survival. Overall, this work provides a comprehensive transcription data atlas throughout the E. multilocularis life cycle. Identification of germinative cell-specific genes and genes important for host-parasite interactions will greatly facilitate future research. A global overview of gene expression profiles will also aide in the detection of suitable drug targets and the development of new chemotherapeutics against alveolar echinococcosis. N2 - Alveoläre Echinokokkose wird durch das Metazestodenstadium des kleinen Fuchsbandwurms Echinococcus multilocularis verursacht und medizinisch als eine schwere Zoonose mit begrenzten Behandlungsmöglichkeiten betrachtet. Um ein besseres Verständnis für die Biologie der Zestoden zu erlangen, wurde das Genom von E. multilocularis, zusammen mit denen anderer Zestoden, bereits sequenziert. Bisher wurden nur wenige Studien zum Transkriptom von E. multilocularis durchgeführt und eine umfassende Analyse der Transkriptionsprofile über verschiedene Stadien des Lebenszyklus hinweg fehlt bislang. Diese Arbeit stellt die bisher umfassendste Untersuchung des Transkriptoms von E. multilocularis dar. Unterschiede in der Genexpression in verschiedenen Stadien des Lebenszyklus und unter experimentellen Bedingungen wurden qualitativ und quantitativ untersucht. Dazu wurden Daten aus RNA-Sequenzierungen in drei biologischen Replikaten verwendet. Die untersuchten Datensätze beruhen auf Proben von Metazestoden, die unter aeroben und anaeroben Bedingungen kultiviert, sowie von Metazestoden, die direkt aus Gerbilen isoliert wurden. Weitere Proben umfassen Stammzellkulturen zu drei verschiedenen Entwicklungszeitpunkten sowie nicht-aktivierte und aktivierte Protoskolizes, das Larvenstadium das sich zu Adulten entwickeln kann. Zusätzlich wurden zwei Datensätze von Metazestoden unter experimentellen Bedingungen, die zur Identifizierung stammzellspezifischer (keimzellspezifischer) Gene geeignet sind, sowie ein Datensatz von einem siRNA-Experiment untersucht. Die Analyse dieser Datensätze führte zu Genexpressionsprofilen für alle annotierten Gene, unter anderem für Gene, die im Tegument des Metazestoden exprimiert werden und eine Rolle spielen bei Wirt-Parasit-Interaktionen und der Modulierung der Immunantwort des Wirts. Genexpressionsprofile liefern zudem Informationen über Gene, die für das infiltrative Wachstum des Parasiten in der Leber verantwortlich sein könnten. Des Weiteren wurden keimzellspezifische Gene identifiziert. Keimzellen sind die einzigen proliferierenden Zellen in E. multilocularis und daher von essentieller Bedeutung für die Entwicklung und das Wachstum des Parasiten. Durch eine Kombination von Keimzelldepletierungs- und Keimzellanreicherungsverfahren wurden Gene mit keimzellspezifischer Expression identifiziert. Wie erwartet, sind viele dieser Gene in der Translation, der Zellzyklusregulation oder DNA-Replikation und –Reparatur involviert. Darüber hinaus wurden keimzellspezifisch exprimierte Transkriptionsfaktoren detektiert, von denen viele in der Festlegung des Zellschicksals eine Rolle spielen. Als Beispiel eines keimzellspezifischen Genes wurde das Gen, das für die reverse Transkriptase (TERT) kodiert, genauer untersucht. Die Expression von E. multilocularis tert in Keimzellen wurde experimentell bestätigt. Zellkulturexperimente weisen darauf hin, dass TERT für die Proliferation und die Entwicklung essentiell ist. TERT ist daher ein potentiell interessantes Wirkstofftarget für die chemotherapeutische Behandlung der alveolären Echinokokkose. Zu den keimzellspezifischen Genen in E. multilocularis gehören auch Gene densoviralen Ursprungs. Es wurden mehr als 20 Densovirusloci mit Informationen für nicht-strukturelle und strukturelle Densovirusproteine im E. multilocularis-Genom identifiziert. Densovirale Elemente wurden auch in vielen anderen Zestodengenomen detektiert. Die genomische Integration dieser Elemente deutet darauf hin, dass densovirus-basierte Vektoren zur genetischen Manipulation von Zestoden geeignet sein könnten. Interessanterweise sind nur drei von mehr als 20 Densovirusloci im E. multilocularis-Genom exprimiert. Da es in Zestoden keinen kanonischen piRNA-Signalweg gibt, stellt sich die Frage nach möglichen Genabschaltungsmechanismen. Die Analyse der RNA-Sequenzierdaten ergab Hinweise auf natürliche Antisense-Transkripte als einen möglichen Genregulationsmechanismus in E. multilocularis. Vorläufige Experimente und bisherige Studien deuten weiterhin darauf hin, dass DNA-Methylierung ein Mechanismus der Genregulation und -abschaltung in Zestoden sein könnte. Die Transkriptionsdaten enthalten auch Informationen zu Genen, die in differenzierten Zellen exprimiert werden, wie zum Beispiel das Serotonintransportergen, das in Nervenzellen exprimiert wird. Zellkulturversuche weisen darauf hin, dass Serotonin und Serotonintransport eine wichtige Rolle bei der Proliferation, der Entwicklung und dem überleben von E. multilocularis spielen. Insgesamt bietet diese Arbeit einen umfassenden Transkriptionsdatenatlas über die Stadien des Lebenszyklus von E. multilocularis. Die Identifizierung von keimzellspezifischen Genen und Genen, die für die Interaktion zwischen Wirt und Parasit wichtig sind, wird die zukünftige Forschung erheblich erleichtern. Ein globaler Überblick über die Genexpressionsprofile wird zudem hilfreich sein bei der Entdeckung geeigneter Wirkstofftargets und bei der Entwicklung neuer Chemotherapeutika gegen die alveoläre Echinokokkose. KW - Fuchsbandwurm KW - Serotonin KW - Telomerase KW - Stammzelle KW - Transkriptomanalyse KW - foxtapeworm KW - transcriptome data analysis KW - germinative cell Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-203802 ER - TY - JOUR A1 - Nyawale, Helmut A. A1 - Moremi, Nyambura A1 - Mohamed, Mohamed A1 - Njwalila, Johnson A1 - Silago, Vitus A1 - Krone, Manuel A1 - Konje, Eveline T. A1 - Mirambo, Mariam M. A1 - Mshana, Stephen E. T1 - High seroprevalence of SARS-CoV-2 in Mwanza, northwestern Tanzania: a population-based survey JF - International Journal of Environmental Research and Public Health N2 - 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. KW - SARS-CoV-2 KW - COVID-19 KW - seroprevalence KW - antibodies KW - Mwanza KW - Tanzania Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288134 SN - 1660-4601 VL - 19 IS - 18 ER - TY - JOUR A1 - Wurmb, Thomas A1 - Scholtes, Katja A1 - Kolibay, Felix A1 - Schorscher, Nora A1 - Ertl, Georg A1 - Ernestus, Ralf-Ingo A1 - Vogel, Ulrich A1 - Franke, Axel A1 - Kowalzik, Barbara T1 - Hospital preparedness for mass critical care during SARS-CoV-2 pandemic JF - Critical Care N2 - 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. KW - Mass critical care KW - Disaster response KW - SARS-CoV-2 KW - Hospital emergency plan Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-230201 VL - 24 ER - TY - JOUR A1 - Brehm, Klaus A1 - Hemer, Sarah A1 - Konrad, Christian A1 - Spiliotis, Markus A1 - Koziol, Uriel A1 - Schaack, Dominik A1 - Förster, Sabine A1 - Gelmedin, Verena A1 - Stadelmann, Britta A1 - Dandekar, Thomas A1 - Hemphill, Andrew T1 - Host insulin stimulates Echinococcus multilocularis insulin signalling pathways and larval development N2 - Background The metacestode of the tapeworm Echinococcus multilocularis is the causative agent of alveolar echinococcosis, a lethal zoonosis. Infections are initiated through establishment of parasite larvae within the intermediate host’s liver, where high concentrations of insulin are present, followed by tumour-like growth of the metacestode in host organs. The molecular mechanisms determining the organ tropism of E. multilocularis or the influences of host hormones on parasite proliferation are poorly understood. Results Using in vitro cultivation systems for parasite larvae we show that physiological concentrations (10 nM) of human insulin significantly stimulate the formation of metacestode larvae from parasite stem cells and promote asexual growth of the metacestode. Addition of human insulin to parasite larvae led to increased glucose uptake and enhanced phosphorylation of Echinococcus insulin signalling components, including an insulin receptor-like kinase, EmIR1, for which we demonstrate predominant expression in the parasite’s glycogen storage cells. We also characterized a second insulin receptor family member, EmIR2, and demonstrated interaction of its ligand binding domain with human insulin in the yeast two-hybrid system. Addition of an insulin receptor inhibitor resulted in metacestode killing, prevented metacestode development from parasite stem cells, and impaired the activation of insulin signalling pathways through host insulin. Conclusions Our data indicate that host insulin acts as a stimulant for parasite development within the host liver and that E. multilocularis senses the host hormone through an evolutionarily conserved insulin signalling pathway. Hormonal host-parasite cross-communication, facilitated by the relatively close phylogenetic relationship between E. multilocularis and its mammalian hosts, thus appears to be important in the pathology of alveolar echinococcosis. This contributes to a closer understanding of organ tropism and parasite persistence in larval cestode infections. Furthermore, our data show that Echinococcus insulin signalling pathways are promising targets for the development of novel drugs. KW - Cestode KW - Tapeworm KW - Echinococcus KW - Echinococcosis KW - Insulin KW - Receptor kinase KW - Kinase inhibitor KW - Host-parasite interaction Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-110357 ER - TY - JOUR A1 - Doran, Kelly S. A1 - Fulde, Marcus A1 - Gratz, Nina A1 - Kim, Brandon J. A1 - Nau, Roland A1 - Prasadarao, Nemani A1 - Schubert-Unkmeir, Alexandra A1 - Tuomanen, Elaine I. A1 - Valentin-Weigand, Peter T1 - Host-pathogen interactions in bacterial meningitis JF - Acta Neuropathologica N2 - 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. KW - microvascular endothelial cells KW - outer membrane protein KW - Neuroinfectiology KW - Bacterial meningitis KW - Pneumococci KW - Meningococci KW - Group B Streptococcus KW - Streptococcus suis KW - Escherichia coli K1 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191034 VL - 131 IS - 2 ER - TY - THES A1 - Nono, Justin T1 - Immunomodulation through Excretory/Secretory Products of the parasitic Helminth Echinococcus multilocularis T1 - Immunmodulation durch Exkretorisch/Sekretorischen Produkten der parasitären Helminthen Echinococcus multilocularis N2 - Die Alveoläre Echinokokkose (AE) ist eine lebensbedrohliche Zoonose, die durch das Metazestoden-Larvenstadium des Fuchsbandwurms Echinococcus multilocularis ausgelöst wird. Nach Eintritt des Parasiten in den Zwischenwirt wird zunächst eine potentiell anti-parasitische, Th1-dominierte Immunantwort ausgelöst, welche anschließend in der chronischen Phase graduell durch eine permissive, Th2-dominierte Antwort ersetzt wird. Als Ergebnis einer zugrunde liegenden Immunmodulation durch den Parasiten können Echinococcus-Larven für Jahre bis Jahrzehnte im Wirt persistieren und verhalten sich ähnlich einem perfekt transplantierten Organ. Über die molekulare Basis der Immunmodulation durch den Parasiten ist derzeit wenig bekannt. In dieser Arbeit wurden geeignete Kultursysteme für verschiedene E. multilocularis Larvenstadien verwendet, um den Einfluss exkretorisch/sekretorischer Metaboliten (E/S-Produkte) auf Wirts-Immuneffektor-Zellen zu studieren. E/S-Produkte kultivierter Larven, die die frühe (Primärzellen) und chronische (Metazestode) Phase der Infektion repräsentieren induzierten Apoptose und tolerogene Eigenschaften in Dendritischen Zellen (DC) des Wirts, während solche von Kontroll-Larven (Protoskolizes) keine derartigen Effekte zeigten. Dies zeigt, dass die frühen infektiösen Stadien von E. multilocularis in DC ein tolerierendes Milieu erzeugen, welches sehr wahrscheinlich die initiale Etablierung des Parasiten in einer Phase begünstigt, in der er höchst sensitiv gegenüber Wirtsangriffen ist. Interessanterweise förderten E/S-Produkte des Metazestoden in vitro die Konversion von CD4+ T-Zellen in Foxp3+, regulatorische T-Zellen (Treg) während E/S-Produkte von Primärzellen oder Protoskolizes dies nicht vermochten. Da Foxp3+ Tregs generell als immunosuppressorisch bekannt sind, deuten diese Daten an, dass der Metazestode aktiv eine Induktion von Tregs herbeiführt, um eine permissive Immunsuppression während einer Infektion zu erreichen. Eine substantielle Zunahme von Anzahl und Frequenz Foxp3+ Tregs konnte zudem in Peritoneal-Exsudaten von Mäuuen nach intraperitonealer Injektion von Parasitengewebe gemessen werden, was anzeigt, dass eine Expansion von Foxp3+ Tregs auch während der in vivo Infektion von Bedeutung ist. Interessanterweise konnte in dieser Arbeit ein Activin-Orthologes des Parasiten, EmACT, identifiziert werden, weleches vom Metazestoden sekretiert wird und ähnlich wie humanes Activin in der Lage ist, eine TGF-β-abhängige Expansion von Tregs in vitro zu induzieren. Dies zeigt an, dass E. multilocularis evolutionsgeschichtlich konservierte Zytokine nutzt, um aktiv die Wirts-Immunantwort zu beeinflussen. Zusammenfassend deuten die gewonnenen Daten auf eine wichtige Rolle Foxp3+ Tregs, welche u.a. durch EmACT induziert werden, im immunologischen geschehen der AE hin. Ein weiterer Parasiten-Faktor, EmTIP, mit signifikanten Homologien zum T-cell Immunomodulatory Protein (TIP) des Menschen wurde in dieser Arbeit näher charakterisiert. EmTIP konnte in der E/S-Fraktion von Primärzellen nachgewiesen werden und induzierte die Freisetzung von IFN-γ in CD4+ T-Helferzellen. Durch Zugabe von anti-EmTIP-Antikörpern konnte zudem die Entwicklung des Parasiten zum Metazestoden in vitro gehemmt werden. EmTIP dürfte daher einerseits bei der frühen Parasiten-Entwicklung im Zwischenwirt eine Rolle spielen und könnte im Zuge dessen auch die Ausprägung der frühen, Th-1-dominierten Immunantwort während der AE begünstigen. Zusammenfassend wurden in dieser Arbeit zwei E. multilocularis E/S-Faktoren identifiziert, EmACT und EmTIP, die ein hohes immunmodulatorisches Potential besitzen. Die hier vorgestellten Daten liefern neue, fundamentale Einsichten in die molekularen Mechanismen der Parasiten-induzierten Immunmodulation bei der AE und sind hoch relevant für die Entwicklung anti-parasitischer Immuntherapien. N2 - Alveolar echinococcosis (AE) is a severe and life-threatening disease caused by the metacestode larva of the fox-tapeworm Echinococcus multilocularis. Parasite entry into the host evokes an early and potentially parasiticidal Th1 immune response that is gradually replaced by a permissive Th2 response. An immunoregulatory environment has also been reported in the host as the disease progresses. As a result of immunomodulation, E. multilocularis larvae persist in the host for decades without being expelled, and thus almost act like a perfect transplant. Very little is currently known on the molecular basis of the host immunomodulation by E. multilocularis. In this work, in vitro cultivation systems were used to assess the influence of metabolites released by the parasite larvae (E/S products) on host immune effector cells. E/S products of cultivated larvae that respresent the early (primary cells) and chronic (metacestode vesicles) phase of AE induced apoptosis and tolerogenic properties (poor responsiveness to LPS stimulation) in host dendritic cells (DC) whereas those of control larvae (protoscoleces) failed to do so. These findings show that the early infective stage of E. multilocularis induces tolerogenicity in host DC, which is most probably important for generating an immunosuppressive environment at an infection phase in which the parasite is highly vulnerable to host attacks. Interestingly, metacestode E/S products promoted the conversion of naïve CD4+ T-cells into Foxp3+ regulatory T-cells in vitro, whereas primary cell and protoscolex E/S products failed to do it. Since Foxp3+ regulatory T-cells are generally known to mediate immunosuppression, the present finding indicates that Foxp3+ regulatory T-cells, expanded by E/S products of the metacestode larva, could play a role in the parasite-driven immunomodulation of the host observed during AE. Furthermore, a substantial increase in number and frequency of suppressive Foxp3+ regulatory T-cells could be observed within peritoneal exudates of mice following intraperitoneal injection of E. multilocularis metacestodes, indicating that Foxp3+ regulatory T-cells could also play an important role in E. multilocularis-driven immunomodulation in vivo. Interestingly, a parasite activin ortholog, EmACT, secreted by metacestodes, was shown to expand host regulatory T-cells in a TGF-β-dependent manner, similarly to mammalian activin A. This observation indicated that E. multilocularis utilizes evolutionarily conserved TGF-β superfamily ligands, like EmACT, to expand host regulatory T-cells. Taken together, the present findings suggest EmACT, a parasite activin secreted by the metacestode and capable of expanding host regulatory T-cells, as an important player in the host immunomodulation by E. multilocularis larvae. Another parasite factor EmTIP, homologous to mammalian T-cell immunomodulatory protein (TIP) was characterized in this work. EmTIP could be detected in the secretions of the parasite primary cells and localized to the intercellular space within the parasite larvae. EmTIP blockade inhibited the proliferation of E. multilocularis primary cells and the formation of metacestode vesicles indicating a major role for parasite development. Furthermore, EmTIP evoked a strong release of IFN-γ by CD4+ T-cells hence suggesting that the secretion of this factor as a result of its role in parasite development could “secondarily” induce a potentially protective Th1 response. In conclusion, this work identified two molecules, EmACT and EmTIP, with high immunomodulatory potential that are released by E. multilocularis larvae. The data presented do provide insights into the mechanisms of parasite-driven host immunomodulation during AE that are highly relevant for the development of anti-parasitic immune therapies. KW - Immunmodulation KW - Fuchsbandwurm KW - Regulatorischer T-Lymphozyt KW - Dendritische Zelle KW - Immunomodulation KW - Helminths KW - Tapeworm KW - Echinococcus KW - Regulatory T-cell KW - Dendritic cell KW - Würmer Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-85449 ER - TY - JOUR A1 - Brehony, Carina A1 - Trotter, Caronline L. A1 - Ramsay, Mary E. A1 - Chandra, Manosree A1 - Jolley, Keith A. A1 - van der Ende, Arie A1 - Carion, Françoise A1 - Berthelsen, Lene A1 - Hoffmann, Steen A1 - Harðardóttir, Hjördís A1 - Vazques, Julio A. A1 - Murphy, Karen A1 - Toropainen, Maija A1 - Caniça, Manuela A1 - Ferreira, Eugenia A1 - Diggle, Mathew A1 - Edwards, Giles F. A1 - Taha, Muhamed-Kheir A1 - Stefanelli, Paola A1 - Kriz, Paula A1 - Gray, Steve J. A1 - Fox, Andrew J. A1 - Jacobsson, Susanne A1 - Claus, Heike A1 - Vogel, Ulrich A1 - Tzanakaki, Georgina A1 - Heuberger, Sigrid A1 - Caugant, Dominique A. A1 - Frosch, Matthias A1 - Maiden, Martin C. J. T1 - Implications of Differential Age Distribution of Disease-Associated Meningococcal Lineages for Vaccine Development JF - Clinical and Vaccine Immunology : CVI N2 - New vaccines targeting meningococci expressing serogroup B polysaccharide have been developed, with some being licensed in Europe. Coverage depends on the distribution of disease-associated genotypes, which may vary by age. It is well established that a small number of hyperinvasive lineages account for most disease, and these lineages are associated with particular antigens, including vaccine candidates. A collection of 4,048 representative meningococcal disease isolates from 18 European countries, collected over a 3-year period, were characterized by multilocus sequence typing (MLST). Age data were available for 3,147 isolates. The proportions of hyperinvasive lineages, identified as particular clonal complexes (ccs) by MLST, differed among age groups. Subjects <1 year of age experienced lower risk of sequence type 11 (ST-11) cc, ST-32 cc, and ST-269 cc disease and higher risk of disease due to unassigned STs, 1- to 4-year-olds experienced lower risk of ST-11 cc and ST-32 cc disease, 5- to 14-year-olds were less likely to experience ST-11 cc and ST-269 cc disease, and ≥25-year-olds were more likely to experience disease due to less common ccs and unassigned STs. Younger and older subjects were vulnerable to a more diverse set of genotypes, indicating the more clonal nature of genotypes affecting adolescents and young adults. Knowledge of temporal and spatial diversity and the dynamics of meningococcal populations is essential for disease control by vaccines, as coverage is lineage specific. The nonrandom age distribution of hyperinvasive lineages has consequences for the design and implementation of vaccines, as different variants, or perhaps targets, may be required for different age groups. KW - differential age distribution KW - disease-associated KW - meningococcal lineages KW - vaccine development Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120808 VL - 21 IS - 6 ER - TY - JOUR A1 - Stock, Nina Katharina A1 - Petráš, Petr A1 - Melter, Oto A1 - Kapounová, Gabriela A1 - Vopalková, Petra A1 - Kubele, Jan A1 - Vaniš, Václav A1 - Tkadlec, Jan A1 - Bukáčková, Eva A1 - Machová, Ivana A1 - Jindrák, Vlastimil T1 - Importance of Multifaceted Approaches in Infection Control: A Practical Experience from an Outbreak Investigation JF - PLoS ONE N2 - 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. KW - multifaceted approaches KW - infection control KW - Methicillin resistant Staphylococcus aureus KW - MRSA Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166891 VL - 11 IS - 6 ER - TY - JOUR A1 - Kohlmorgen, Britta A1 - Elias, Johannes A1 - Schoen, Christoph T1 - Improved performance of the artus Mycobacterium tuberculosis RG PCR kit in a low incidence setting: a retrospective monocentric study JF - Scientific Reports N2 - Tuberculosis (TB) and the spread of Mycobacterium tuberculosis complex (MTBC) strains resistant against rifampin (RIF) and isoniazid (INH) pose a serious threat to global health. However, rapid and reliable MTBC detection along with RIF/INH susceptibility testing are challenging in low prevalence countries due to the higher rate of false positives. Here, we provide the first performance data for the artus MTBC PCR assay in a low prevalence setting. We analyze 1323 respiratory and 311 non-respiratory samples with the artus MTBC PCR assay as well as by mycobacterial culture and microscopy. We propose retesting of specimens in duplicate and consideration of a determined cycle-threshold value cut-off greater than 34, as this significantly increases accuracy, specificity, and negative predictive value without affecting sensitivity. Furthermore, we tested fourteen MTBC positive samples with the GenoType MTBDRplus test and demonstrate that using an identical DNA extraction protocol for both assays does not impair downstream genotypic testing for RIF and INH susceptibility. In conclusion, our procedure optimizes the use of the artus MTB assay with workload efficient methods in a low incidence setting. Combining the modified artus MTB with the GenoType MTBDRplus assays allows rapid and accurate detection of MTBC and RIF/INH resistance. KW - laboratory techniques and procedures KW - Tuberculosis Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159248 VL - 7 IS - 14127 ER - TY - JOUR A1 - Walter, T. A1 - Collenburg, L. A1 - Japtok, L. A1 - Kleuser, B. A1 - Schneider-Schaulies, S. A1 - Müller, N. A1 - Becam, J. A1 - Schubert-Unkmeir, A. A1 - Kong, J. N. A1 - Bieberich, E. A1 - Seibel, J. T1 - Incorporation and visualization of azido-functionalized N-oleoyl serinol in Jurkat cells, mouse brain astrocytes, 3T3 fibroblasts and human brain microvascular endothelial cells JF - Chemical Communications N2 - The synthesis and biological evaluation of azido-N-oleoyl serinol is reported. It mimicks biofunctional lipid ceramides and has shown to be capable of click reactions for cell membrane imaging in Jurkat and human brain microvascular endothelial cells. KW - Ceramide KW - Apoptosis KW - Golgi KW - N-oleoyl serinol KW - Jurkat cells Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-191263 VL - 52 IS - 55 ER - TY - JOUR A1 - Gomes, Sara F. Martins A1 - Westermann, Alexander J. A1 - Sauerwein, Till A1 - Hertlein, Tobias A1 - Förstner, Konrad U. A1 - Ohlsen, Knut A1 - Metzger, Marco A1 - Shusta, Eric V. A1 - Kim, Brandon J. A1 - Appelt-Menzel, Antje A1 - Schubert-Unkmeir, Alexandra T1 - Induced pluripotent stem cell-derived brain endothelial cells as a cellular model to study Neisseria meningitidis infection JF - Frontiers in Microbiology N2 - 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. KW - Neisseria meningitidis KW - meningococcus KW - bacteria KW - stem cells KW - blood-cerebrospinal fluid barrier KW - blood-brain barrier KW - brain endothelial cells Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201562 VL - 10 IS - 1181 ER - TY - THES A1 - Lee, Sae Kyung T1 - Interaction of Helicobacter pylori flagellins with the host innate immune system T1 - Interaktion von Helicobacter pylori Flagellin mit dem angeborenen Immunsystem des Wirtes N2 - Helicobacter pylori (H. pylori) is a gram-negative, microaerophilic, spiral-shaped bacterium. It resides in the gastric mucous layer and epithelial lining of the stomach, often clustering at the junction of epithelial cells. H. pylori colonization usually occurs during childhood, and, when left untreated, generally persists for the host’s lifetime. Persistent H. pylori infection can cause chronic superficial gastritis and gastric duodenal ulcers, which is possibly linked to the development of gastric carcinoma and primary gastric lymphoma, especially of the mucosa-associated lymphoid tissue (MALT) type. It was recently defined as a class 1 carcinogen. The gastric inflammatory response to H. pylori infection is characterized by infiltration of the mucosa by neutrophils, T and B cells, plasma cells and macrophages. This reaction is initially induced by H. pylori attachment, followed by cytokine release by gastric epithelial cells. Epidemiological studies revealed that more than 50% of adults are infected with H. pylori all over the world. However, interestingly, only a subset of individuals develops serious H. pylori-related disease, while most infected individuals show no clinical symptoms. Gastric epithelial cells, like intestinal epithelial cells, express a subset of Toll-like receptors (TLRs) and similar pattern recognition receptors, which are important for the activation of the innate immune system. Bacterial components such as lipopeptides, peptidoglycan, LPS, flagellin, and CpG DNA are the ligands of TLRs. Thus, TLRs in gastric epithelial cells might be able to contribute to innate immune responses to H. pylori infection. However, there is scant knowledge about the mechanisms of innate immune response to acute and chronic H. pylori infection. This study is focused on host cell interaction with H. pylori flagellins, which are major components of the flagellar apparatus, and innate immune responses against them. The flagellins, which are essential for bacterial motility, are important for H. pylori to survive in the stomach mucus during the whole infectious cycle. Flagellins are known to act as the main determinant of many mucosal pathogenic bacteria that mediates proinflammatory signaling, including transcriptional factor NF-B activation via TLR5. In the first part of the study, we investigated the effects of H. pylori flagellins on TLR5 expression, NF-B activation and IL-8 production in various human intestinal and gastric epithelial cell lines by using Western blotting, semi-quantitative RT-PCR and ELISA. IL-8 is a potent neutrophil-activating chemokine expressed by gastric epithelial cells. When we stimulated the cells with the native form of or E. coli-expressed recombinant H. pylori flagellins, FlaA and FlaB, IL-8 was not induced in any case, while S. typhimurium flagellin (FliC) induced it significantly. H. pylori was able to modulate TLR5 protein expression and NF-B activation in epithelial cells regardless of the presence of flagellins. Having established the finding that H. pylori flagellins have unusually low immune-stimulatory properties, we further investigated to find out possible reasons why H. pylori flagellins are distinct from other flagellins of pathogenic bacteria in terms of immune-stimulatory activity. From amino acid sequence comparisons, we found that some regions in the terminal D0D1 protein domains of H. pylori flagellins are different from flagellins of other pathogenic bacteria. D0D1 is the domain which is known to interact with TLR5 in Salmonella FliC. To examine whether the differences endow H. pylori flagellins with low immune-stimulatory properties, we created several mutated H. pylori flagellins (FlaA and FlaB) by site-directed mutagenesis that contain one to four epitopes of Salmonella flagellin D0D1 domain amino acid sequences. The mutant flagellins expressed both in H. pylori and E. coli were used to determine their influence on TLR5-signaling mediators and cytokines, such as MAPkinases, (ERK, p38), NF-B, IL-8, and MIP-3. Salmonella FliC expressed in E. coli induced activation of p38, IB and NF-B leading to IL-8 and MIP-3 production in gastric epithelial cells. However, none of the H. pylori flagellin mutants activated MAP kinases or induced those cytokines. In a co-immunoprecipitation assay none of the recombinant wild type or mutated H. pylori flagellins showed any direct physical interaction with TLR5, while Salmonella FliC significantly co-precipitated with TLR5. Interestingly, we found H. pylori flagellins bind to the surface of gastric epithelial cells like FliC, although they do not bind to or stimulate TLR5. Based on the physical interaction of H. pylori flagellins and FliC with human gastric epithelial cells, we further analyzed transcriptional regulation by H. pylori flagellin in these host cells using microarray analysis. The result showed that H. pylori flagellins modulate host cell gene expression, and many of the identified regulation events overlap with the genes regulated by FliC. These findings imply that H. pylori flagellins do play a role in gene regulation of host cells probably through still unknown factors or receptors, although they do not trigger TLR5-related signaling pathways. The results of our study suggest that, in addition to the low immune-stimulatory activity of H. pylori LPS, the evolutionary reduction in stimulating activity of H. pylori flagellins on the local innate immune responses in the stomach in vivo might be a further strategy of this chronic mucosal pathogen to evade and minimize deleterious host responses, thereby promoting life-long persistence in the host, and possibly contributing to cancerogenesis. N2 - Helicobacter pylori (H. pylori) ist ein gram-negatives, mikroaerophiles, spiralförmiges Bakterium. Es besiedelt die Schleimschicht und die Epitheloberfläche des Magens, wobei es sich besonders an den Kontaktstellen der Epithelzellen anlagert. Die Kolonisation mit H. pylori erfolgt normalerweise während der Kindheit und bleibt, wenn sie nicht behandelt wird, im allgemeinen während der gesamten Lebenszeit des Wirtes bestehen. Die persistierende H. pylori-Infektion kann chronische oberflächliche Gastritis und Zwöffingerdarmgeschwüre verursachen. Die Infektion kann auch zur Entwicklung von Magenkrebs und Lymphomen des Mukosa-assoziierten Lymphgewebes (MALT-Lymphom) führen. H. pylori ist seit 1994 als Typ I-Karzinogen klassifiziert. Die durch eine H. pylori-Infektion induzierte Entzündungsreaktion der Magenschleimhaut ist charakterisiert durch eine Infiltration der Schleimhaut mit neutrophilen Granulozyten, T- und B-Zellen, Plasmazellen und Makrophagen. Diese Reaktion wird ausgelöst durch die Anheftung von H. pylori gefolgt von der Freisetzung von Cytokinen durch die Magenepithelzellen. Epidemiologische Studien haben ergeben, dass weltweit mehr als 50% aller Erwachsenen mit H. pylori infiziert sind. Jedoch entwickelt interessanterweise nur eine Teilgruppe der infizierten Individuen eine ernsthafte H. pylori-assoziierte Krankheit, während die meisten Infizierten keine klinischen Symptome zeigen. Magenepithelzellen exprimieren, genauso wie Darmepithelzellen, eine Reihe von TOLL-like Rezeptoren (TLRs) und ähnliche Musterekennungsrezeptoren, die wichtig für die Aktivierung des angeborenen Immunsystems sind. Bakterielle Komponenten, wie z. B. Lipopeptide, Peptidoglycan, LPS, Flagellin und CpG-DNA sind die Liganden der TLRs. Auf diese Weise könnten die TLRs in den Magenepithelzellen in der Lage sein, zu der angeborenen Immunreaktion auf eine H. pylori-Infektion beizutragen. Jedoch ist bisher nur wenig über die Mechanismen der angeborenen Immunreaktion auf eine akute und chronische H. pylori-Infektion bekannt. Diese Studie befasst sich mit den Zellinteraktionen mit und den Antworten des Wirtsimmunsystems auf H. pylori-Flagelline, stark exprimierte Proteine des Flagellenapparats. Der Flagellenapparat ist essentiell für die Fähigkeit der Bakterien, im Magenschleim (Mukus) beweglich zu sein, und befähigt die Bakterien dazu, während des gesamten Infektionszyklus im Mukus und an der Magenmukosa zu überleben. Flagellin ist für viele pathogene Bakterien im Intestinaltrakt oder auch in der Lunge des Säuger-Wirts ein sehr wichtiger Faktor, der durch Bindung an TLR5 proinflammatorische Signalvorgänge, einschließlich der Aktivierung des Transkriptionsfaktors NF-B, herbeiführt. Im ersten Teil der vorliegenden Studie haben wir die Wirkungen von H. pylori-Flagellinen (FlaA, FlaB) auf TLR5-Expression, NF-B-Aktivierung und IL-8-Produktion in verschiedenen menschlichen Darm- und Magenepithelzelllinien mittels Western Blot, semi-quantitativer RT-PCR und ELISA untersucht. IL-8 ist ein hochwirksames Neutrophilen-aktivierendes Chemokin, welches von den Magenepithelzellen sezerniert wird und als ein Marker für die Zellaktivierung durch H. pylori, seine löslichen Produkte und Kontrollen diente. Nach Stimulation verschiedener Epithelzellen und humaner Makrophagen mit nativen oder in E. coli rekombinant hergestellten H. pylori-Flagellinen FlaA und FlaB wurde in keinem Fall IL-8 gebildet, während S. typhimurium-Flagellin (FliC) IL-8-Bildung und -Sekretion in signifikanter Menge induzierte. H. pylori war in der Lage, TLR5-Protein-Expression und die NF-B-Aktivierung in Epithelzellen zu modulieren, unabhängig von dem Vorhandensein von Flagellinen. Nachdem wir gezeigt hatten, dass H. pylori-Flagelline ungewöhnlich geringe immunstimulierende Eigenschaften besitzen, setzten wir unsere Untersuchungen fort, um mögliche Gründe herauszufinden, warum H. pylori-Flagelline sich von anderen Flagellinen pathogener Bakterien hinsichtlich der das Immunsystem stimulierenden Aktivitäten unterscheiden. Bei Vergleichen von Aminosäuresequenzen fanden wir heraus, dass einige Regionen in den terminalen D0D1-Domänen der H. pylori-Flagelline sich von Flagellinen anderer pathogener Bakterien unterscheiden. D0D1 ist der Funktionsbereich des Flagellins, von dem bekannt ist, dass er bei Salmonellen-FliC mit TLR5 interagiert. Um zu untersuchen, ob diese Unterschiede für die geringe immunstimulierende Wirkung von H. pylori-Flagellinen verantwortlich sind, generierten wir durch eine zielgerichtete Mutagenese mehrere mutierte H. pylori-Flagelline (FlaA und FlaB), die ein bis vier Epitope der Aminosäuresequenzen der D0D1-Domäne des Salmonella-Flagellins enthielten. Die mutierten Flagelline, die sowohl in H. pylori als auch in E. coli exprimiert wurden, wurden genutzt, um ihren Einfluss auf TLR5-Signal-Mediatoren und Cytokine, wie z. B. MAP-Kinasen (ERK, p38), NF-B, IL-8 und MIP-3α herauszufinden. In E. coli exprimiertes Salmonella-FliC bewirkte die Aktivierung von p38, IB, NF-B und ERK und führte zur Produktion von IL-8 und MIP-3α in den Magenepithelzellen. Im Gegensatz dazu aktivierte keine der H. pylori-Flagellinmutanten MAP-Kinasen oder induzierte diese Cytokine. Wir konnten durch Koimmunpräzipitationstechniken zeigen, dass wildtypische oder mutierte H. pylori-Flagelline nicht physisch mit TLR5 interagieren, während Salmonella-FliC spezifisch an TLR5 bindet. Interessanterweise fanden wir heraus, dass H. pylori-Flagelline wie FliC an die Oberfläche verschiedener humaner Epithelzellen binden, obwohl sie nicht TLR5 stimulieren oder an TLR5 binden. Basierend auf der physischen Interaktion von H. pylori-Flagellinen und FliC mit menschlichen Magenepithelzellen haben wir weiterhin die Transkriptionsregulation durch H. pylori-Flagellin in den Wirtszellen mit Hilfe der Microarray-Analyse untersucht. Die Ergebnisse zeigten, dass H. pylori-Flagelline die Gene der Wirtszelle modulieren, und viele der identifizierten Regulationsereignisse überschnitten sich mit den durch FliC regulierten Genen. Diese Ergebnisse implizieren, dass H. pylori-Flagelline doch eine Rolle bei der Genregulierung von Wirtszellen spielen, wahrscheinlich durch noch unbekannte Faktoren und Rezeptoren, obwohl sie keine mit TLR5 in Zusammenhang stehenden Signaltransduktionsketten auslösen. Die Resultate unserer Studien lassen darauf schließen, dass zusätzlich zu der das Immunsystem nur gering stimulierenden Aktivität von H. pylori-LPS die evolutionäre Reduzierung der stimulierenden Aktivität von H. pylori-Flagellinen auf lokale angeborene Immunreaktionen im Magen in vivo eine weitere Strategie dieses chronischen Schleimhautpathogens sein könnte, um schädliche Wirtsreaktionen zu verhindern und zu minimieren und hierdurch seine lebenslange Persistenz, jedoch auch die Krebsentstehung im Wirt zu fördern. KW - Helicobacter pylori KW - TLR5 KW - Helicobacter KW - Flagellin KW - angeborene Immunität KW - TLR5 KW - Helicobacter KW - Flagellin KW - Innate immunity Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-19917 ER - TY - JOUR A1 - Forster, Johannes A1 - Dichtl, Karl A1 - Wagener, Johannes T1 - Lower beta‐1,3‐D‐glucan testing cut‐offs increase sensitivity for non‐albicans Candida species bloodstream infections JF - Mycoses N2 - 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. KW - antigen testing KW - BDG KW - beta‐d‐glucan KW - bloodstream infection KW - candidemia KW - mannan Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-276515 VL - 65 IS - 5 SP - 500 EP - 507 ER - TY - JOUR A1 - Kurotschka, Peter Konstantin A1 - Tiedemann, Elena A1 - Wolf, Dominik A1 - Thier, Nicola A1 - Forster, Johannes A1 - Liese, Johannes G. A1 - Gagyor, Ildiko T1 - Management of common infections in German primary care: a cross-sectional survey of knowledge and confidence among General Practitioners and outpatient pediatricians JF - Antibiotics N2 - 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. KW - infectious diseases management KW - general practitioner KW - pediatrician KW - primary care KW - outpatient KW - antibiotic use KW - antimicrobial resistance KW - antimicrobial stewardship KW - survey KW - knowledge Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-246272 SN - 2079-6382 VL - 10 IS - 9 ER - TY - JOUR A1 - Schoen, Christoph A1 - Kischkies, Laura A1 - Elias, Johannes A1 - Ampattu, Biju Joseph T1 - Metabolism and virulence in Neisseria meningitidis N2 - A longstanding question in infection biology addresses the genetic basis for invasive behavior in commensal pathogens. A prime example for such a pathogen is Neisseria meningitidis. On the one hand it is a harmless commensal bacterium exquisitely adapted to humans, and on the other hand it sometimes behaves like a ferocious pathogen causing potentially lethal disease such as sepsis and acute bacterial meningitis. Despite the lack of a classical repertoire of virulence genes in N. meningitidis separating commensal from invasive strains, molecular epidemiology suggests that carriage and invasive strains belong to genetically distinct populations. In recent years, it has become increasingly clear that metabolic adaptation enables meningococci to exploit host resources, supporting the concept of nutritional virulence as a crucial determinant of invasive capability. Here, we discuss the contribution of core metabolic pathways in the context of colonization and invasion with special emphasis on results from genome-wide surveys. The metabolism of lactate, the oxidative stress response, and, in particular, glutathione metabolism as well as the denitrification pathway provide examples of how meningococcal metabolism is intimately linked to pathogenesis. We further discuss evidence from genome-wide approaches regarding potential metabolic differences between strains from hyperinvasive and carriage lineages and present new data assessing in vitro growth differences of strains from these two populations. We hypothesize that strains from carriage and hyperinvasive lineages differ in the expression of regulatory genes involved particularly in stress responses and amino acid metabolism under infection conditions. KW - Neisseria meningitidis KW - virulence KW - pathometabolism KW - oxidative stress KW - glutathione KW - γ-glutamyl cycle KW - glutamate dehydrogenase KW - nitrite respiration Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113118 ER - TY - JOUR A1 - Ruf, Dominik A1 - Brantl, Victor A1 - Wagener, Johannes T1 - Mitochondrial Fragmentation in \(Aspergillus\) \(fumigatus\) as Early Marker of Granulocyte Killing Activity JF - Frontiers in Cellular and Infection Microbiology N2 - 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. KW - Aspergillus fumigatus KW - killing KW - assay KW - PMNs KW - granulocytes KW - mitochondria KW - mitochondrial morphology KW - fungicidal activity Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-227133 VL - 8 IS - 128 ER - TY - THES A1 - Konrad, Christian T1 - Molecular analysis of insulin signaling mechanisms in Echinococcus multilocularis and their role in the host-parasite interaction in the alveolar echinococcosis T1 - Molekulare Analyse der Insulin-Signalmechanismen in Echinococcus multilocularis und ihre Rolle in der Wirt-Parasiten-Interaktion in der Alveolären Echinokokkose N2 - The insulin receptor ortholog EmIR of the fox-tapeworm Echinococcus multilocularis displays significant structural homology to the human insulin receptor (HIR) and has been suggested to be involved in insulin sensing mechanisms of the parasite’s metacestode larval stage. In the present work, the effects of host insulin on Echinococcus metacestode vesicles and the proposed interaction between EmIR and mammalian insulin have been studied using biochemical and cell-biological approaches. Human insulin, exogenously added to in vitro cultivated parasite larvae, (i) significantly stimulated parasite survival and growth, (ii) induced DNA de novo synthesis in Echinococcus, (iii) affected overall protein phosphorylation in the parasite, and (iv) specifically induced the phosphorylation of the parasite’s Erk-like MAP kinase orthologue EmMPK1. These results clearly indicated that Echinococcus metacestode vesicles are able to sense exogenous host insulin which induces a mitogenic response. To investigate whether EmIR mediates these effects, anti-EmIR antibodies were produced and utilized in biochemical assays and immunohistochemical analyses. EmIR was shown to be expressed in the germinal layer of the parasite both on the surface of glycogen storing cells and undifferentiated germinal cells. Upon addition of exogenous insulin to metacestode vesicles, the phosphorylation of EmIR was significantly induced, an effect which was suppressed in the presence of specific inhibitors of insulin receptor-like tyrosine kinases. Furthermore, upon expression of EmIR/HIR receptor chimera containing the extracellular ligand binding domain of EmIR in HEK 293 cells, a specific autophosphorylation of the chimera could be induced through the addition of exogenous insulin. These results indicated the capability of EmIR to sense and to transmit host insulin signals to the Echinococcus signaling machinery. The importance of insulin signaling mechanisms for parasite survival and growth were underscored by in vitro cultivation experiments in which the addition of an inhibitor of insulin receptor tyrosine kinases led to vesicle degradation and death. Based on the above outlined molecular data on the interaction between EmIR and mammalian insulin, the parasite’s insulin receptor orthologue most probably mediates the insulin effects on parasite growth and is, therefore, a potential candidate factor for host-parasite communication via evolutionary conserved pathways. In a final set of experiments, signaling mechanisms that act downstream of EmIR have been analyzed. These studies revealed significant differences between insulin signaling in Echinococcus and the related cestode parasite Taenia solium. These differences could be associated with differences in the organo-tropism of both species. N2 - Der orthologe Insulinrezeptor EmIR des Fuchsbandwurmes Echinococcus multilocularis weist signifikante strukturelle Homologie zum humanen Insulinrezeptor (HIR) auf. Es wurde schon seit geraumer Zeit vermutet, dass EmIR an den Mechanismen beteiligt sein könnte, die es dem Metacestoden Larvenstadium des Parasiten erlauben Insulin zu detektieren. In dieser Arbeit wurden die Effekte von Wirtsinsulin auf Echinococcus Metacestoden-Vesikel und die vermutete Interaktion zwischen EmIR und Insulin von Säugern mittels biochemischer und zellbiologischer experimenteller Ansätze untersucht. Die exogene Zugabe von humanem Insulin zu in vitro kultivierten Parasitenlarven hatte folgende Effekte: (i) das Überleben und das Wachstum des Parasiten wurde signifikant stimuliert; (ii) die DNA de novo Synthese in Echinococcus wurde induziert; (iii) die generelle Proteinphosphorylierung des Parasiten wurde beeinflusst; (iv) die Phosphorylierung der orthologen Erk-like MAP Kinase, EmMPK1, des Parasiten wurde spezifisch induziert. Diese Beobachtungen zeigen deutlich, dass Echinococcus Metacestoden-Vesikel exogenes Insulin des Wirtes detektieren können und dass dieses Insulin einen mitogenischen Effekt auf den Parasiten hat. Um zu untersuchen, ob diese Effekte durch EmIR vermittelt werden, wurden anti-EmIR Antikörper hergestellt und in biochemischen experimentellen Ansätzen und immunohistochemischen Analysen eingesetzt. Es konnte gezeigt werden, dass EmIR in der Germinalschicht des Parasiten expremiert wird, sowohl an der Oberfläche von Glykogen-Speicherzellen als auch von undifferenzierten Germinalzellen. Nach der Zugabe von exogenem Insulin konnte eine signifikante Zunahme der Phosphorylierung von EmIR festgestellt werden. Diese Stimulierung konnte durch die Zugabe eines spezifischen Inhibitors für Insulinrezeptor-ähnliche Tyrosinkinasen unterdrückt werden. Desweiteren konnte mittels der Expression eines chimären EmIR/HIR-Rezeptors, der die extrazelluläre Ligandenbindungsdomäne von EmIR enthielt, in HEK293 Zellen gezeigt werden, dass die Zugabe von exogenem Insulin eine spezifische Autophosphorylierung der Chimäre induziert. Diese Ergebnisse bezeugen die Fähigkeit von EmIR Insulin-abhängige Signale des Wirtes einerseits zu detektieren und andererseits an die Echinococcus Signalwege weiter zu leiten. Die Bedeutung von Insulin-Signalmechanismen für das Überleben und das Wachstum des Parasiten konnte durch in vitro Kultivierungsexperimente aufgezeigt werden. Die Zugabe eines Inhibitors spezifisch für Insulinrezeptor Tyrosinkinasen verursachte die Degradation und den Tod der Metacestoden-Vesikel. Basierend auf den dargelegten molekularen Daten bezüglich der Interaktion zwischen EmIR und Insulin von Säugern erscheint es sehr wahrscheinlich, dass der orthologe Insulinrezeptor des Parasiten die Effekte von Insulin auf das Wachstum des Parasiten vermittelt. Aus diesem Grund ist EmIR ein potentieller Kandidat für die Kommunikation zwischen Wirt und Parasiten mittels evolutionär konservierten Signalwegen. Die Signalmechanismen unterhalb von EmIR wurden in abschließenden Experimenten untersucht. Diese offenbarten deutliche Unterschiede in der Weiterleitung von Insulin induzierten Signalen zwischen Echinococcus und dem verwandten parasitären Zestoden Taenia solium. Diese Unterschiede könnten mit dem unterschiedlichen Organtropismus beider Arten in Verbindung stehen. KW - Fuchsbandwurm KW - Insulin KW - Echinokokkus KW - Insulin KW - Helminth KW - EmERK KW - Echinococcus KW - insulin KW - helminth KW - EmERK Y1 - 2007 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-22636 ER - TY - THES A1 - Koike, Akito T1 - Molekular und zellbiologischer Ansatz hin zu neuartigen Medikamenten gegen \(Echinococcus\) \(multilocularis\) T1 - Molecular and cell biological approach towards novel drugs against \(Echinococcus\) \(multilocularis\) N2 - 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. N2 - Die Echinokokkose ist eine der wichtigsten Zoonosen sowohl für die Human- als auch für die Veterinärmedizin. Der Erreger der alveolären Echinokokkose (AE) ist Echinococcus multilocularis. Metazestode Bläschen, das Larvenstadium dieses parasitären Helminthen, können in die Leber eindringen und ungeschlechtlich wie bösartige Tumore wachsen. Dies kann ohne geeignete Behandlung tödlich sein. Die Behandlung von AE beim Menschen beschränkt sich auf Chirurgie und Chemotherapie, aber die Chirurgie ist nur bei einem kleinen Prozentsatz der Patienten anwendbar, die im Frühstadium diagnostiziert werden. Die meisten Patienten können sich nur auf eine Chemotherapie mit Albendazol (ABZ) verlassen. ABZ wirkt jedoch nur parasitostatisch und kann die Krankheit nicht heilen. Daher muss ABZ über einen längeren Zeitraum eingenommen werden, obwohl es mit Nebenwirkungen einhergeht. Daher ist die Entwicklung eines neuen, parasitentötenden und selektiven Medikaments gegen AE erforderlich. Da die undifferenzierte Stammzellpopulation von E. multilocularis eine Schlüsselrolle für seine Langlebigkeit und Regenerationsfähigkeit spielt, ist eine auf Stammzellen abzielende Chemotherapie wichtig. In dieser Arbeit wurde ein In-vitro-Screening verschiedener Hemmstoffe gegen Kinasen und Tubuline durchgeführt. Das Ergebnis des Screenings zeigte, dass Inhibitoren gegen humane pim-Kinasen starke schädliche Auswirkungen auf E. multilocularis haben. Durch ein Hefe-Zwei- Hybrid-System wurde die Interaktion der Parasiten-Pim-Kinase (EmPIM) mit der Zellteilungszyklus 25 (EmCDC25) nachgewiesen, und durch In-situ-Hybridisierung wurde die teilweise Lokalisierung von EmPIM in den Stammzellen beobachtet. Daher ist es wahrscheinlich, dass EmPim ein positiver Regulator der Zellzyklusprogression ist, genau wie menschliches Pim1. ... KW - Bandwürmer KW - Zellzyklus KW - Benzimidazolderivate KW - tapeworm KW - kinase KW - benzimidazole Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288649 ER - TY - THES A1 - Hemer, Sarah T1 - Molecular characterization of evolutionarily conserved signaling systems of Echinococcus multilocularis and their utilization for the development of novel drugs against Echinococosis T1 - Molekulare Charakterisierung evolutionsgeschichtlich konservierter Signalsysteme und deren Nutzung für die Entwicklung neuer Medikamente gegen Echinococcose N2 - Alveolar echinococcosis (AE), a severe and life-threatening disease is caused by the small fox tapeworm Echinococcus multilocularis. Currently, the options of chemotherapeutic treatment are very limited and are based on benzimidazole compounds, which act merely parasitostatic in vivo and often display strong side effects. Therefore, new therapeutic drugs and targets are urgently needed. In the present work the role of two evolutionarily conserved signalling pathways in E. multilocularis, namely the insulin signalling cascade and Abl kinases, has been studied in regard to host-parasite interaction and the possible use in anti-AE chemotherapy. N2 - Die alveoläre Echinokokkose ist eine ernste und lebensgefährliche Erkrankung, die durch den kleinen Fuchsbandwurm ausgelo ̈st wird. Die gegenwärtigen chemotherapeutischen Behandlungsmöglichkeiten beschränken sich auf die Behandlung mit Benzimidazolen, die in vivo nur parasitostatische Wirkung besitzen und häufig sehr starke Nebenwirkungen aufweisen. Aus diesem Grund besteht ein dringendes Bedürfnis nach neuen Medikamenten und Angriffszielen für diese. In der vorliegenden Arbeit wurde die Rolle zweier evolutionsgeschichtlich konservierter Signalsysteme, der Insulin Signalweg und die Abl Kinasen in E. multilocularis in Hinblick auf die Wirt-Parasiten Interaktion und dem mo ̈glichen Nutzen in der AE Chemotherapie untersucht. KW - Fuchsbandwurm KW - Insulin KW - Chemotherapie KW - Echinococcus KW - Insulin KW - Chemotherapie KW - Imatinib KW - Abl KW - Echinococcus KW - Insulin KW - Chemotherapy KW - Abl KW - Imatinib Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-74007 ER - TY - THES A1 - Herz, Michaela T1 - Molecular characterization of the serotonin and cAMP-signalling pathways in Echinococcus T1 - Molekulare Charakterisierung der Serotonin- und cAMP-Signalwege in Echinococcus N2 - Alveolar and cystic echinococcosis, caused by Echinococcus multilocularis and Echinococcus granulosus respectively, are severe zoonotic diseases with limited treatment options. The sole curative treatment is the surgical removal of the complete parasite material. Due to late diagnosis, chemotherapeutic treatment often is the only treatment option. Treatment is based on benzimidazoles, which merely act parasitostatic and often display strong side effects. Therefore, new therapeutic drugs are urgently needed. Evolutionarily conserved signalling pathways are known to be involved in hostparasite cross-communication, parasite development and survival. Moreover, they represent potential targets for chemotherapeutic drugs. In this context the roles of the serotonin- and cAMP-signalling pathways in Echinococcus were studied. Genes encoding serotonin receptors, a serotonin transporter and enzymes involved in serotonin biosynthesis could be identified in the E. multilocularis and E. granulosus genomes indicating that these parasites are capable of synthesizing and perceiving serotonin signals. Also the influence of exogenous serotonin on parasite development was studied. Serotonin significantly increased metacestode vesicle formation from primary cells and re-differentiation of protoscoleces. Inhibition of serotonin transport with citalopram significantly reduced metacestode vesicle formation from primary cells and caused death of protoscoleces and metacestodes. Furthermore, it could be shown that serotonin increased phosphorylation of protein kinase A substrates. Taken together, these results show that serotonin and serotonin transport are essential for Echinococcus development and survival. Consequently, components of the serotonin pathway represent potential drug targets. In this work the cAMP-signalling pathway was researched with focus on G-protein coupled receptors and adenylate cyclases. 76 G-protein coupled receptors, including members of all major families were identified in the E. multilocularis genome. Four genes homologous to adenylate cyclase IX were identified in the E. multilocularis genome and three in the E. granulosus genome. While glucagon caused no significant effects, the adenylate cyclase activator forskolin and the adenylate cyclase inhibitor 2’, 5’ didesoxyadenosine influenced metacestode vesicle formation from primary cells, re-differentiation of protoscoleces and survival of metacestodes. It was further shown that forskolin increases phosphorylation of protein kinase A substrates, indicating that forskolin activates the cAMP-pathway also in cestodes. These results indicate that the cAMP signalling pathway plays an important role in Echinococcus development and survival. To complement this work, the influence of different media and additives on E. granulosus protoscoleces was investigated. Anaerobic conditions and the presence of FBS prolonged protoscolex survival while different media influenced protoscolex activation and development. Taken together, this work provided important insights into developmental processes in Echinococcus and potential drug targets for echinococcosis chemotherapy. N2 - Alveoläre und zystische Echinokokkose, hervorgerufen durch Echinococcus multilocularis und Echinococcus granulosus, sind schwere zoonotische Erkrankungen mit eingeschränkten Behandlungsmöglichkeiten. Die einzig kurative Therapie besteht in der chirurgischen Entfernung des gesammten Parasitenmaterials. Aufgrund später Diagnosestellung stellt Chemotherapie oft die einzige Behandlungsmöglichkeit dar. Die derzeitige Therapie basiert auf Benzimidazolen, welche nur parasitostatisch wirken und oft schwere Nebenwirkungen hervorrufen. Neue Medikamente werden daher dringend benötigt. Evolutionär konservierte Signalwege sind bekanntermaßen an Wirt-Parasit Kreuzkommunikation, Parasitenentwicklung und deren Überleben beteiligt. Darüber hinaus stellen sie auch mögliche Angriffspunkte für Chemotherapeutika dar. In diesem Zusammenhang wurden die Rollen des Serotonin- und des cAMP-Signalwegs in Echinococcus untersucht. Gene für Serotoninrezeptoren, einen Serotonintransporter und für Enzyme, die in der Serotoninsynthese involviert sind, konnten in den E. multilocularis und E. granulosus Genomen identifiziert werden, was darauf schließen lässt, dass diese Parasiten in der Lage sind, Serotonin selbst herzustellen und zu sensieren. Des Weiteren wurde der Einfluss von exogenem Serotonin auf die Parasitenentwicklung untersucht. Serotonin förderte die Bildung von Metazestodenvesikeln aus Primärzellen und die Rückdifferenzierung von Protoskolizes signifikant. Die Hemmung des Serotonintransports mit Citalopram reduzierte die Bildung von Metazestodenvesikeln aus Primärzellen signifikant und führte zum Absterben von Protoskolizes undMetazestoden. Des Weiteren konnte gezeigt werden, dass Serotonin die Posphorylierung von Proteinkinase A Substraten erhöht. Zusammengefasst zeigen diese Ergebnisse, dass Serotonin und Serotonintransport essentiell f¨ur die Entwicklung und das Überleben von Echinococcus sind. Folglich stellen Komponenten des Serotoninsignalwegs potentielle Angriffspunkte für Medikamente dar. In dieser Arbeit wurde der cAMP-Signalweg mit Schwerpunkt auf G-Protein gekoppelte Rezeptoren und Adenylatzyklasen untersucht. 76 G-Protein gekoppelte Rezeptoren, inclusive Mitglieder aller Hauptfamilien, wurden im E. multilocularis-Genom identifiziert. Vier Homologe zur Adenylatzyklase IX wurden im E. multilocularis- Genom und drei im E. granulosus-Genom identifiziert. Während Glukagon keine signifikanten Effekte hervorrief, beeinflussten der Adenylatzyklase-Aktivator Forskolin und der Adenylatzyklase-Inhibitor 2’, 5’-Didesoxyadenosin die Bildung von Metazestodenvesikeln aus Primärzellen, die Rückdifferenzierung von Protoskolizes und das Überleben vonMetazestoden. Zudem wurde gezeigt, dass Forskolin die Phosphorylierung von Proteinkinase A-Substraten erhöht. Dies bestätigt, dass Forskolin den cAMP-Signalweg aktiviert. Diese Ergebnisse legen nahe, dass der cAMP-Signalweg eine wichtige Rolle in der Entwicklung und dem Überleben von Echinococcus spielt. Um diese Arbeit zu vervollständigen, wurde der Einfluss von verschiedenen Medien und Zusätzen auf E. granulosus Protoskolizes untersucht. Anaerobe Bedingungen und die Anwesenheit von FBS verlängerten das Überleben von Protoskolizes, während verschiedene Medien die Aktivierung und die Entwicklung von Protoskolizes beeinflussten. Insgesamt gibt diese Arbeit wichtige Einblicke in Entwicklungsprozesse von Echinococcus und zeigt potentielle Angriffspunkte für Medikamente auf. KW - Serotonin KW - Cyclo-AMP KW - Fuchsbandwurm KW - cAMP KW - Echinococcus Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-139249 ER - TY - JOUR A1 - Zoran, Tamara A1 - Seelbinder, Bastian A1 - White, Philip Lewis A1 - Price, Jessica Sarah A1 - Kraus, Sabrina A1 - Kurzai, Oliver A1 - Linde, Joerg A1 - Häder, Antje A1 - Loeffler, Claudia A1 - Grigoleit, Goetz Ulrich A1 - Einsele, Hermann A1 - Panagiotou, Gianni A1 - Loeffler, Juergen A1 - Schäuble, Sascha T1 - Molecular profiling reveals characteristic and decisive signatures in patients after allogeneic stem cell transplantation suffering from invasive pulmonary aspergillosis JF - Journal of Fungi N2 - 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. KW - host response KW - invasive pulmonary aspergillosis KW - alloSCT patients KW - galectin-2 KW - caspase-3 KW - matrix metallopeptidase-1 Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-262105 SN - 2309-608X VL - 8 IS - 2 ER - TY - JOUR A1 - Silwedel, Christine A1 - Haarmann, Axel A1 - Fehrholz, Markus A1 - Claus, Heike A1 - Speer, Christian P. A1 - Glaser, Kirsten T1 - More than just inflammation: Ureaplasma species induce apoptosis in human brain microvascular endothelial cells JF - Journal of Neuroinflammation N2 - 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. KW - Ureaplasma urealyticum KW - Ureaplasma parvum KW - Neuroinflammation KW - Meningitis KW - Caspase KW - Apoptosis KW - HBMEC Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-200711 VL - 16 ER - TY - JOUR A1 - Schubert-Unkmeir, Alexandra A1 - Konrad, Christian A1 - Slanina, Heiko A1 - Czapek, Florian A1 - Hebling, Sabrina A1 - Frosch, Matthias T1 - Neisseria meningitidis Induces Brain Microvascular Endothelial Cell Detachment from the Matrix and Cleavage of Occludin: A Role for MMP-8 N2 - Disruption of the blood-brain barrier (BBB) is a hallmark event in the pathophysiology of bacterial meningitis. Several inflammatory mediators, such as tumor necrosis factor alpha (TNF-a), nitric oxide and matrix metalloproteinases (MMPs), contribute to this disruption. Here we show that infection of human brain microvascular endothelial cells (HBMEC) with Neisseria meningitidis induced an increase of permeability at prolonged time of infection. This was paralleled by an increase in MMP-8 activity in supernatants collected from infected cells. A detailed analysis revealed that MMP-8 was involved in the proteolytic cleavage of the tight junction protein occludin, resulting in its disappearance from the cell periphery and cleavage to a lower-sized 50-kDa protein in infected HBMEC. Abrogation of MMP-8 activity by specific inhibitors as well as transfection with MMP-8 siRNA abolished production of the cleavage fragment and occludin remained attached to the cell periphery. In addition, MMP-8 affected cell adherence to the underlying matrix. A similar temporal relationship was observed for MMP activity and cell detachment. Injury of the HBMEC monolayer suggested the requirement of direct cell contact because no detachment was observed when bacteria were placed above a transwell membrane or when bacterial supernatant was directly added to cells. Inhibition of MMP-8 partially prevented detachment of infected HBMEC and restored BBB permeability. Together, we established that MMP-8 activity plays a crucial role in disassembly of cell junction components and cell adhesion during meningococcal infection. KW - Neisseria meningitidis Y1 - 2010 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-68589 ER - TY - JOUR A1 - Silwedel, Christine A1 - Speer, Christian P. A1 - Haarmann, Axel A1 - Fehrholz, Markus A1 - Claus, Heike A1 - Buttmann, Mathias A1 - Glaser, Kirsten T1 - 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 JF - Journal of Neuroinflammation N2 - 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. KW - atypical chemokine receptor 3 KW - human brain microvascular endothelial cells KW - meningitis KW - neuroinflammation KW - Ureaplasma species Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175952 VL - 15 IS - 156 ER - TY - JOUR A1 - Brehm, Klaus A1 - Koziol, Uriel T1 - On the importance of targeting parasite stem cells in anti-echinococcosis drug development T1 - De l’importance de cibler les cellules souches du parasite dans la recherche de nouveaux médicaments contre les échinococcoses JF - Parasite N2 - The life-threatening diseases alveolar and cystic echinococcoses are caused by larvae of the tapeworms Echinococcus multilocularis and E. granulosus, respectively. In both cases, intermediate hosts, such as humans, are infected by oral uptake of oncosphere larvae, followed by asexual multiplication and almost unrestricted growth of the metacestode within host organs. Besides surgery, echinococcosis treatment relies on benzimidazole-based chemotherapy, directed against parasite beta-tubulin. However, since beta-tubulins are highly similar between cestodes and humans, benzimidazoles can only be applied at parasitostatic doses and are associated with adverse side effects. Mostly aiming at identifying alternative drug targets, the nuclear genome sequences of E. multilocularis and E. granulosus have recently been characterized, revealing a large number of druggable targets that are expressed by the metacestode. Furthermore, recent cell biological investigations have demonstrated that E. multilocularis employs pluripotent stem cells, called germinative cells, which are the only parasite cells capable of proliferation and which give rise to all differentiated cells. Hence, the germinative cells are the crucial cell type mediating proliferation of E. multilocularis, and most likely also E. granulosus, within host organs and should also be responsible for parasite recurrence upon discontinuation of chemotherapy. Interestingly, recent investigations have also indicated that germinative cells might be less sensitive to chemotherapy because they express a beta-tubulin isoform with limited affinity to benzimidazoles. In this article, we briefly review the recent findings concerning Echinococcus genomics and stem cell research and propose that future research into anti-echinococcosis drugs should also focus on the parasite’s stem cell population. N2 - Les échinococcoses alvéolaire et kystique, deux maladies potentiellement mortelles, sont respectivement causées par les larves des vers plats Echinococcus multilocularis et E. granulosus. Dans les deux cas, les hôtes intermédiaires, comme l’homme, s’infectent par l’ingestion des oncosphères, suivie de la multiplication asexuée et la croissance presque illimitée du métacestode dans les organes de l’hôte. À côté de la chirurgie, le traitement des échinococcoses repose sur une chimiothérapie par les benzimidazoles, dont l’action est dirigée contre la bêta-tubuline du parasite. Cependant, comme les bêta-tubulines sont extrêmement similaires chez les cestodes et les humains, les benzimidazoles ne peuvent être utilisés qu’à des posologies parasitostatiques et sont associés à des effets secondaires indésirables. Avec l’objectif principal d’identifier des cibles pour des médicaments alternatifs, le génome nucléaire d’E. multilocularis et d’E. granulosus a été récemment séquencé, et de nombreuses cibles potentielles pour des médicaments sont exprimées par le métacestode. De plus, des études récentes de biologie cellulaire ont montré qu’E. multilocularis dispose de cellules souches multipotentes, appelées cellules germinales, qui sont les seules cellules parasitaires capables de prolifération et à l’origine de toutes les cellules différenciées. Ces cellules germinales représentent donc un type cellulaire crucial pour la prolifération d’E. multilocularis, et très vraisemblablement aussi d’E. granulosus, dans les organes de l’hôte, et vraisemblablement responsables des récurrences parasitaires à l’arrêt de la chimiothérapie. Des études récentes ont aussi indiqué que les cellules germinales pourraient être moins sensibles à la chimiothérapie car elles expriment un isoforme de la bêta-tubuline à affinité limitée vis-à-vis des benzimidazoles. Dans cet article, nous faisons une courte revue des découvertes récentes concernant la génomique d’Echinococcus et la recherche sur les cellules souches. Nous proposons que les recherches futures sur de nouveaux médicaments contre les échinococcoses se focalisent sur la population des cellules souches du parasite. KW - genome KW - chemotherapy KW - benzimidazole KW - stem cells KW - germinative cells KW - beta-tubulin Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-118030 SN - 1252-607X VL - 21 ER - TY - JOUR A1 - Hubert, Kerstin A1 - Pawlik, Marie-Christin A1 - Claus, Heike A1 - Jarva, Hanna A1 - Meri, Seppo A1 - Vogel, Ulrich T1 - Opc Expression, LPS Immunotype Switch and Pilin Conversion Contribute to Serum Resistance of Unencapsulated Meningococci JF - PLoS One N2 - Neisseria meningitidis employs polysaccharides and outer membrane proteins to cope with human serum complement attack. To screen for factors influencing serum resistance, an assay was developed based on a colorimetric serum bactericidal assay. The screening used a genetically modified sequence type (ST)-41/44 clonal complex (cc) strain lacking LPS sialylation, polysaccharide capsule, the factor H binding protein (fHbp) and MutS, a protein of the DNA repair mechanism. After killing of >99.9% of the bacterial cells by serum treatment, the colorimetric assay was used to screen 1000 colonies, of which 35 showed enhanced serum resistance. Three mutant classes were identified. In the first class of mutants, enhanced expression of Opc was identified. Opc expression was associated with vitronectin binding and reduced membrane attack complex deposition confirming recent observations. Lipopolysaccharide (LPS) immunotype switch from immunotype L3 to L8/L1 by lgtA and lgtC phase variation represented the second class. Isogenic mutant analysis demonstrated that in ST-41/44 cc strains the L8/L1 immunotype was more serum resistant than the L3 immunotype. Consecutive analysis revealed that the immunotypes L8 and L1 were frequently observed in ST-41/44 cc isolates from both carriage and disease. Immunotype switch to L8/L1 is therefore suggested to contribute to the adaptive capacity of this meningococcal lineage. The third mutant class displayed a pilE allelic exchange associated with enhanced autoaggregation. The mutation of the C terminal hypervariable region D of PilE included a residue previously associated with increased pilus bundle formation. We suggest that autoaggregation reduced the surface area accessible to serum complement and protected from killing. The study highlights the ability of meningococci to adapt to environmental stress by phase variation and intrachromosomal recombination affecting subcapsular antigens. KW - factor H KW - C-reactive protein KW - B neisseria meningitidis KW - outer membrane protein KW - phase variation KW - serogroup B KW - bactericidal activity KW - epithelial cells KW - gene conversion KW - strain MC58 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135421 VL - 7 IS - 9 ER - TY - JOUR A1 - Kim, Brandon J. A1 - Shusta, Eric V. A1 - Doran, Kelly S. T1 - Past and current perspectives in modeling bacteria and blood–brain barrier interactions JF - Frontiers in Microbiology N2 - The central nervous system (CNS) barriers are highly specialized cellular barriers that promote brain homeostasis while restricting pathogen and toxin entry. The primary cellular constituent regulating pathogen entry in most of these brain barriers is the brain endothelial cell (BEC) that exhibits properties that allow for tight regulation of CNS entry. Bacterial meningoencephalitis is a serious infection of the CNS and occurs when bacteria can cross specialized brain barriers and cause inflammation. Models have been developed to understand the bacterial – BEC interaction that lead to pathogen crossing into the CNS, however, these have been met with challenges due to these highly specialized BEC phenotypes. This perspective provides a brief overview and outlook of the in vivo and in vitro models currently being used to study bacterial brain penetration, and opinion on improved models for the future. KW - bacteria KW - blood–brain barrier KW - meningitis KW - stem cells KW - brain endothelial cell Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201766 VL - 10 IS - 1336 ER - TY - JOUR A1 - Häder, Antje A1 - Schäuble, Sascha A1 - Gehlen, Jan A1 - Thielemann, Nadja A1 - Buerfent, Benedikt C. A1 - Schüller, Vitalia A1 - Hess, Timo A1 - Wolf, Thomas A1 - Schröder, Julia A1 - Weber, Michael A1 - Hünniger, Kerstin A1 - Löffler, Jürgen A1 - Vylkova, Slavena A1 - Panagiotou, Gianni A1 - Schumacher, Johannes A1 - Kurzai, Oliver T1 - Pathogen-specific innate immune response patterns are distinctly affected by genetic diversity JF - Nature Communications N2 - 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. KW - antimicrobial responses KW - immunogenetics Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-357441 VL - 14 ER - TY - JOUR A1 - Krüger, Sören A1 - Leskien, Miriam A1 - Schuller, Patricia A1 - Prifert, Christiane A1 - Weißbrich, Benedikt A1 - Vogel, Ulrich A1 - Krone, Manuel T1 - Performance and feasibility of universal PCR admission screening for SARS‐CoV‐2 in a German tertiary care hospital JF - Journal of Medical Virology N2 - 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. KW - admission screening KW - COVID‐19 KW - infection control KW - SARS‐CoV‐2 KW - testing strategy Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-238971 VL - 93 IS - 5 SP - 2890 EP - 2898 ER - TY - JOUR A1 - Elias, Johannes A1 - Findlow, Jamie A1 - Borrow, Ray A1 - Tremmel, Angelika A1 - Frosch, Matthias A1 - Vogel, Ulrich T1 - Persistence of antibodies in laboratory staff immunized with quadrivalent meningococcal polysaccharide vaccine JF - Journal of Occupational Medicine and Toxicology N2 - 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. KW - Vaccination KW - Meningococcal infection KW - Biohazard KW - Meningococcal polysaccharide caccine Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-95953 UR - http://www.occup-med.com/content/8/1/4 ER - TY - JOUR A1 - Schwerk, Christian A1 - Papandreou, Thalia A1 - Schuhmann, Daniel A1 - Nickol, Laura A1 - Borkowski, Julia A1 - Steinmann, Ulrike A1 - Quednau, Natascha A1 - Stump, Carolin A1 - Weiss, Christel A1 - Berger, Jürgen A1 - Wolburg, Hartwig A1 - Claus, Heike A1 - Vogel, Ulrich A1 - Ishikawa, Hiroshi A1 - Tenenbaum, Tobias A1 - Schroten, Horst T1 - Polar Invasion and Translocation of Neisseria meningitidis and Streptococcus suis in a Novel Human Model of the Blood-Cerebrospinal Fluid Barrier JF - PLoS One N2 - Acute bacterial meningitis is a life-threatening disease in humans. Discussed as entry sites for pathogens into the brain are the blood-brain and the blood-cerebrospinal fluid barrier (BCSFB). Although human brain microvascular endothelial cells (HBMEC) constitute a well established human in vitro model for the blood-brain barrier, until now no reliable human system presenting the BCSFB has been developed. Here, we describe for the first time a functional human BCSFB model based on human choroid plexus papilloma cells (HIBCPP), which display typical hallmarks of a BCSFB as the expression of junctional proteins and formation of tight junctions, a high electrical resistance and minimal levels of macromolecular flux when grown on transwell filters. Importantly, when challenged with the zoonotic pathogen Streptococcus suis or the human pathogenic bacterium Neisseria meningitidis the HIBCPP show polar bacterial invasion only from the physiologically relevant basolateral side. Meningococcal invasion is attenuated by the presence of a capsule and translocated N. meningitidis form microcolonies on the apical side of HIBCPP opposite of sites of entry. As a functionally relevant human model of the BCSFB the HIBCPP offer a wide range of options for analysis of disease-related mechanisms at the choroid plexus epithelium, especially involving human pathogens. KW - gene expression KW - plexus epithelial-cells KW - central-nervous-system KW - microvascular endothelial-cells KW - choroid-plexus KW - in vitro KW - brain barrier KW - tight junctions KW - meningococcal disease KW - bacterial meningitis Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131459 VL - 7 IS - 1 ER - TY - JOUR A1 - Dick, Julia A1 - Krauß, Patrizia A1 - Hillenkamp, Jost A1 - Kohlmorgen, Britta A1 - Schoen, Christoph T1 - Postoperative Tropheryma whipplei endophthalmitis – a case report highlighting the additive value of molecular testing JF - JMM Case Reports N2 - 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. KW - intravitreal vancomycin and amikacin KW - intravenous ceftriaxone KW - topic ofloxacin KW - Whipple's disease KW - endophthalmitis KW - Tropheryma whipplei KW - ocular infection KW - vitrectomy KW - oral cefpodoxime KW - oral doxycycline Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-158823 VL - 4 ER - TY - JOUR A1 - Prauße, Maria T. E. A1 - Lehnert, Teresa A1 - Timme, Sandra A1 - Hünniger, Kerstin A1 - Leonhardt, Ines A1 - Kurzai, Oliver A1 - Figge, Marc Thilo T1 - Predictive Virtual Infection Modeling of Fungal Immune Evasion in Human Whole Blood JF - Frontiers in Immunology N2 - 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. KW - immune evasion KW - state-based model KW - innate immune response KW - polymorphonuclear neutrophils KW - whole-blood infection assay Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197493 SN - 1664-3224 VL - 9 IS - 560 ER - TY - JOUR A1 - Moremi, Nyambura A1 - Mshana, Stephen E. A1 - Kamugisha, Erasmus A1 - Kataraihya, Johannes B. A1 - Tappe, Dennis A1 - Vogel, Ulrich A1 - Lyamuya, Eligius F. A1 - Claus, Heike T1 - Predominance of methicillin resistant Staphylococcus aureus-ST88 and new ST1797 causing wound infection and abscesses JF - Journal of Infection in Developing Countries N2 - Introduction: Although there has been a worldwide emergence and spread of methicillin-resistant Staphylococcus aureus (MRSA), little is known about the molecular epidemiology of MRSA in Tanzania. Methodology: In this study, we characterized MRSA strains isolated from clinical specimens at the Bugando Medical Centre, Tanzania, between January and December 2008. Of 160 S. aureus isolates from 600 clinical specimens, 24 (15%) were found to be MRSA. Besides molecular screening for the Panton Valentine leukocidin (PVL) genes by PCR, MRSA strains were further characterized by Multi-Locus Sequence Typing (MLST) and spa typing. Results: Despite considerable genetic diversity, the spa types t690 (29.1%) and t7231 (41.6%), as well as the sequence types (ST) 88 (54.2%) and 1797 (29.1%), were dominant among clinical isolates. The PVL genes were detected in 4 isolates; of these, 3 were found in ST 88 and one in ST1820. Resistance to erythromycin, clindamicin, gentamicin, tetracycline and co-trimoxazole was found in 45.8%, 62.5%, 41.6%, 45.8% and 50% of the strains, respectively. Conclusion: We present the first thorough typing of MRSA at a Tanzanian hospital. Despite considerable genetic diversity, ST88 was dominant among clinical isolates at the Bugando Medical Centre. Active and standardized surveillance of nosocomial MRSA infection should be conducted in the future to analyse the infection and transmission rates and implement effective control measures. KW - Tanzania KW - panton-valentine leukocidin KW - field gel-electrophoreresis KW - molecular epidemiology KW - aureus infections KW - MRSA KW - ST88 KW - ST1797 Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-134746 VL - 6 IS - 8 ER - TY - JOUR A1 - Deogratias, Anna-Pendo A1 - Mushi, Martha F. A1 - Paterno, Laurent A1 - Tappe, Dennis A1 - Seni, Jeremiah A1 - Kabymera, Rogatus A1 - Kidenya, Benson R. A1 - Mshana, Stephen E. T1 - Prevalence and determinants of Campylobacter infection among under five children with acute watery diarrhea in Mwanza, North Tanzania JF - Archives of Public Health N2 - BACKGROUND: Campylobacteriosis, a zoonotic bacterial disease observed world-wide, is becoming the most commonly recognized cause of bacterial gastroenteritis in humans. This study was done to determine the prevalence and determinants of Campylobacter infection among under-fives with acute watery diarrhea in Mwanza City, Tanzania. METHOD: This cross-sectional hospital-based study was conducted at Bugando Medical Centre (BMC) and Sekou Toure Hospital in Mwanza City. All inpatients and outpatients under-fives who met the inclusion criteria from October 2012 to April 2013 were enrolled in the study. Demographic and clinical data were obtained using standardized data collection tools. Stool samples were collected for gram staining and culture for Campylobacter spp. on Preston selective agar media. In addition, blood slides for malaria and HIV tests were done to all patients. RESULTS: A total of 300 children were enrolled with a median age of 12 [interquartile range, 8-19] months. Of these, 169 (56.5%) were from BMC and 131 (43.7%) from Sekou-Toure hospital. One hundred and seventy (56.7%) of the participating children were male. Of 300 under-fives with acute watery diarrhea, 29 patients (9.7%) were found to have Campylobacter infection. A significant higher number of children with Campylobacter infection were found in Sekou Toure hospital compared to BMC [16.0% (21/29) versus 4.7% (8/29), p = 0.002)]. Age above 2 years was independently found to predict campylobacter infection (OR: 2.9, 95% CI 1.1-7.7, p = 0.0037). Of 30 patients with a positive blood slide for Plasmodium falciparum, 20.0% were also positive for Campylobacter infection (OR: 3.9, 95% CI 1.2-10.1, p = 0.021). CONCLUSION: Campylobacter infection shows a comparatively low prevalence in under-fives with acute watery diarrhea in Mwanza city and is independently associated with positive slides for malaria and an age above 2 years. Further studies are needed to type the most prevalent Campylobacter species and to determine their antibiotic susceptibility pattern. KW - acute watery diarrhea KW - campylobacteriosis KW - under five children Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-120749 VL - 72 IS - 17 ER - TY - JOUR A1 - Elias, Johannes A1 - Heuschmann, Peter U. A1 - Schmitt, Corinna A1 - Eckhardt, Frithjof A1 - Boehm, Hartmut A1 - Maier, Sebastian A1 - Kolb-Mäurer, Annette A1 - Riedmiller, Hubertus A1 - Müllges, Wolfgang A1 - Weisser, Christoph A1 - Wunder, Christian A1 - Frosch, Matthias A1 - Vogel, Ulrich T1 - Prevalence dependent calibration of a predictive model for nasal carriage of methicillin-resistant Staphylococcus aureus JF - BMC Infectious Diseases N2 - 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. KW - Methicillin-resistant staphylococcus aureus KW - Infection control KW - Clinical prediction rule KW - Predictive value of tests KW - False positive reactions KW - Calibration Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96091 UR - http://www.biomedcentral.com/1471-2334/13/111 ER - TY - JOUR A1 - Bauer, Hannah A1 - Concha Mendoza, Gustavo Andrés A1 - Kreienbrock, Lothar A1 - Hartmann, Maria A1 - Frickmann, Hagen A1 - Kann, Simone T1 - Prevalence of common diseases in Indigenous people in Colombia JF - Tropical Medicine and Infectious Disease N2 - 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. KW - Chagas disease KW - indigenous KW - public health KW - Colombia KW - Sierra Nevada KW - neglected groups Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-278953 SN - 2414-6366 VL - 7 IS - 6 ER - TY - JOUR A1 - Duske, Helene A1 - Claus, Heike A1 - Krone, Manuel A1 - Lâm, Thiên-Trí T1 - Prevalence of piperacillin/tazobactam resistance in invasive \(Haemophilus\) \(influenzae\) in Germany JF - JAC-Antimicrobial Resistance N2 - 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. KW - microbiology KW - immunology KW - generalized anxiety disorder KW - haemophilus influenzae KW - agar KW - Germany KW - piperacillin KW - piperacillin/tazobactam KW - tazobactam KW - Haemophilus influenzae Y1 - 2024 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350424 SN - 2632-1823 VL - 6 IS - 1 ER - TY - JOUR A1 - Nell, Manuel A1 - Burgkart, Rainer H. A1 - Gradl, Guntmar A1 - von Eisenhart-Rothe, Rüdiger A1 - Schaeffeler, Christoph A1 - Trappe, Dennis A1 - Prazeres da Costa, Clarissa A1 - Gradinger, Reiner A1 - Kirchhoff, Chlodwig T1 - Primary extrahepatic alveolar echinococcosis of the lumbar spine and the psoas muscle JF - Annals of Clinical Microbiology and Antimicrobials N2 - Alveolar echinococcosis (AE) of human being caused by Echinococcus multilocularis is a rare but important zoonosis especially in tempered zones of middle Europe and Northern America with endemic character in many countries. Due to the long incubation period, various clinical manifestations, critical prognosis, and outcome AE presents a serious and severe disease. The primary focus of infection is usually the liver. Although secondary affection of visceral organs is possible extrahepatic AE is highly uncommon. Moreover, the involvement of bone and muscle presents with an even lower incidence. In the literature numerous cases on hepatic AE have been reported. However, extrahepatic AE involving bones and/or muscles was described very rarely. We report a case of an 80-year-old man with primary extrahepatic alveolar Echinococcosis of the lumbar spine and the psoas muscle. The etiology, diagnosis, differential diagnoses, treatment options and outcome of this rare disease are discussed in context with the current literature. KW - Medicine Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141796 VL - 10 IS - 13 ER - TY - JOUR A1 - Vendelova, Emilia A1 - de Lima, Jeferson Camargo A1 - Lorenzatto, Karina Rodrigues A1 - Monteiro, Karina Mariante A1 - Mueller, Thomas A1 - Veepaschit, Jyotishman A1 - Grimm, Clemens A1 - Brehm, Klaus A1 - Hrčková, Gabriela A1 - Lutz, Manfred B. A1 - Ferreira, Henrique B. A1 - Nono, Justin Komguep T1 - Proteomic Analysis of Excretory-Secretory Products of Mesocestoides corti Metacestodes Reveals Potential Suppressors of Dendritic Cell Functions JF - PLoS Neglected Tropical Diseases N2 - Accumulating evidences have assigned a central role to parasite-derived proteins in immunomodulation. Here, we report on the proteomic identification and characterization of immunomodulatory excretory-secretory (ES) products from the metacestode larva (tetrathyridium) of the tapeworm Mesocestoides corti (syn. M. vogae). We demonstrate that ES products but not larval homogenates inhibit the stimuli-driven release of the pro-inflammatory, Th1-inducing cytokine IL-12p70 by murine bone marrow-derived dendritic cells (BMDCs). Within the ES fraction, we biochemically narrowed down the immunosuppressive activity to glycoproteins since active components were lipid-free, but sensitive to heat- and carbohydrate-treatment. Finally, using bioassay-guided chromatographic analyses assisted by comparative proteomics of active and inactive fractions of the ES products, we defined a comprehensive list of candidate proteins released by M. corti tetrathyridia as potential suppressors of DC functions. Our study provides a comprehensive library of somatic and ES products and highlight some candidate parasite factors that might drive the subversion of DC functions to facilitate the persistence of M. corti tetrathyridia in their hosts. KW - proteomic analysis KW - excretory-secretory KW - Mesocestoides corti Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166742 VL - 10 IS - 10 ER - TY - JOUR A1 - Wagener, Johannes A1 - Loiko, Veronika T1 - Recent insights into the paradoxical effect of echinocandins JF - Journal of Fungi N2 - 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. KW - echinocandin KW - caspofungin KW - micafungin KW - anidulafungin KW - paradoxical effect KW - paradoxical growth KW - glucan synthase KW - Fks1 KW - antifungals KW - echinocandins Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-197960 SN - 2309-608X VL - 4 IS - 1 ER - TY - JOUR A1 - Weiss, Esther A1 - Schlegel, Jan A1 - Terpitz, Ulrich A1 - Weber, Michael A1 - Linde, Jörg A1 - Schmitt, Anna-Lena A1 - Hünniger, Kerstin A1 - Marischen, Lothar A1 - Gamon, Florian A1 - Bauer, Joachim A1 - Löffler, Claudia A1 - Kurzai, Oliver A1 - Morton, Charles Oliver A1 - Sauer, Markus A1 - Einsele, Hermann A1 - Loeffler, Juergen T1 - Reconstituting NK Cells After Allogeneic Stem Cell Transplantation Show Impaired Response to the Fungal Pathogen Aspergillus fumigatus JF - Frontiers in Immunology N2 - 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. KW - natural killer cell KW - stem cell transplantation KW - corticosteroids KW - CCL3 KW - CCL4 KW - CCL5 Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-212581 SN - 1664-3224 VL - 11 ER - TY - JOUR A1 - Hellenbrand, Wiebke A1 - Claus, Heike A1 - Schink, Susanne A1 - Marcus, Ulrich A1 - Wichmann, Ole A1 - Vogel, Ulrich T1 - Risk of Invasive Meningococcal Disease in Men Who Have Sex with Men: Lessons Learned from an Outbreak in Germany, 2012-2013 JF - PLoS ONE N2 - 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. KW - invasive meningococcal disease KW - men who have sex with men KW - Germany Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-166842 VL - 11 IS - 8 ER - TY - JOUR A1 - Barth, Thomas F. E. A1 - Herrmann, Tobias S. A1 - Tappe, Dennis A1 - Stark, Lorenz A1 - Grüner, Beate A1 - Buttenschoen, Klaus A1 - Hillenbrand, Andreas A1 - Juchems, Markus A1 - Henne-Bruns, Doris A1 - Kern, Petra A1 - Seitz, Hanns M. A1 - Möller, Peter A1 - Rausch, Robert L. A1 - Kern, Peter A1 - Deplazes, Peter T1 - Sensitive and Specific Immunohistochemical Diagnosis of Human Alveolar Echinococcosis with the Monoclonal Antibody Em2G11 JF - PLoS Neglected Tropical Diseases N2 - 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. KW - cells KW - multilocularis KW - antigen Y1 - 2012 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135371 VL - 6 IS - 10 ER -