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Decker R.,Institute For Medizinische Mikrobiologie | Burdelski C.,Institute For Medizinische Mikrobiologie | Zobiak M.,Institute For Medizinische Mikrobiologie | Buttner H.,Institute For Medizinische Mikrobiologie | And 12 more authors.
PLoS Pathogens | Year: 2015

Virulence of the nosocomial pathogen Staphylococcus epidermidis is crucially linked to formation of adherent biofilms on artificial surfaces. Biofilm assembly is significantly fostered by production of a bacteria derived extracellular matrix. However, the matrix composition, spatial organization, and relevance of specific molecular interactions for integration of bacterial cells into the multilayered biofilm community are not fully understood. Here we report on the function of novel 18 kDa Small basic protein (Sbp) that was isolated from S. epidermidis biofilm matrix preparations by an affinity chromatographic approach. Sbp accumulates within the biofilm matrix, being preferentially deposited at the biofilm–substratum interface. Analysis of Sbp-negative S. epidermidis mutants demonstrated the importance of Sbp for sustained colonization of abiotic surfaces, but also epithelial cells. In addition, Sbp promotes assembly of S. epidermidis cell aggregates and establishment of multilayered biofilms by influencing polysaccharide intercellular-adhesin (PIA) and accumulation associated protein (Aap) mediated intercellular aggregation. While inactivation of Sbp indirectly resulted in reduced PIA-synthesis and biofilm formation, Sbp serves as an essential ligand during Aap domain-B mediated biofilm accumulation. Our data support the conclusion that Sbp serves as an S. epidermidis biofilm scaffold protein that significantly contributes to key steps of surface colonization. Sbp-negative S. epidermidis mutants showed no attenuated virulence in a mouse catheter infection model. Nevertheless, the high prevalence of sbp in commensal and invasive S. epidermidis populations suggests that Sbp plays a significant role as a co-factor during both multi-factorial commensal colonization and infection of artificial surfaces. © 2015 Decker et al.


Christner M.,Institute For Medizinische Mikrobiologie | Franke G.C.,Institute For Medizinische Mikrobiologie | Schommer N.N.,Institute For Medizinische Mikrobiologie | Wendt U.,Institute For Medizinische Mikrobiologie | And 8 more authors.
Molecular Microbiology | Year: 2010

Virulence of nosocomial pathogen Staphylococcus epidermidis is essentially related to formation of adherent biofilms, assembled by bacterial attachment to an artificial surface and subsequent production of a matrix that mediates interbacterial adhesion. Growing evidence supports the idea that proteins are functionally involved in S. epidermidis biofilm accumulation. We found that in S. epidermidis 1585v overexpression of a 460 kDa truncated isoform of the extracellular matrix-binding protein (Embp) is necessary for biofilm formation. Embp is a giant fibronectin-binding protein harbouring 59 Found In Various Architectures (FIVAR) and 38 protein G-related albumin-binding (GA) domains. Studies using defined Embp-positive and -negative S. epidermidis strains proved that Embp is sufficient and necessary for biofilm formation. Further data showed that the FIVAR domains of Embp mediate binding of S. epidermidis to solid-phase attached fibronectin, constituting the first step of biofilm formation on conditioned surfaces. The binding site in fibronectin was assigned to the fibronectin domain type III12. Embp-mediated biofilm formation also protected S. epidermidis from phagocytosis by macrophages. Thus, Embp is a multifunctional cell surface protein that mediates attachment to host extracellular matrix, biofilm accumulation and escape from phagocytosis, and therefore is well suited for promoting implant-associated infections. © 2009 Blackwell Publishing Ltd.


PubMed | Dr. Horst Schmidt Kliniken GmbH, University of Munster, Labor Berlin Charite Vivantes GmbH, Institute For Medizinische Mikrobiologie Und Krankenhaushygiene and 16 more.
Type: Journal Article | Journal: International journal of medical microbiology : IJMM | Year: 2016

Aim of this study was to determine the incidence and molecular epidemiology of carbapenemase-producing Escherichia coli and Klebsiella pneumoniae in Germany. E. coli and K. pneumoniae isolates from clinical samples which were non-susceptible to carbapenems were collected in laboratories serving 20 hospitals throughout Germany from November 2013 to April 2014. The isolates were tested for the presence of carbapenemases by PCR and phenotypic methods and typed by multilocus sequence typing. Risk factors including a previous hospitalization abroad were analysed. Carbapenemases were detected in 24 isolates from 22 patients out of 464,514 admissions. Carbapenemases included OXA-48 (n=14), KPC-2 (n=8) and NDM-1 (n=2). Except for two K. pneumoniae isolates with ST101, all OXA-48 producing strains belonged to different clones. In contrast, half of KPC-2 producing K. pneumoniae were of ST258 and both NDM-1 producing strains were of ST11. Compared to carbapenem-susceptible controls, patients with carbapenemase-producing strains differed by a significantly higher proportion of males, a higher proportion of isolates from wound samples and a more frequent previous stay abroad in univariate analysis. This multicentre study demonstrated an incidence of carbapenemase-producing E. coli and K. pneumoniae from clinical samples in Germany of 0.047 cases per 1000 admissions. OXA-48 was more frequent than KPC-2 and NDM-1 and showed a multiclonal background.


Adamzik M.,Universitatsklinikum Essen | Schafer S.,Universitatsklinikum Essen | Frey U.H.,Universitatsklinikum Essen | Becker A.,Universitatsklinikum Essen | And 9 more authors.
Anesthesiology | Year: 2013

Background: Because the nuclear factor-κB (NF-κB) coupled pathway is believed to amplify inflammation prevailing in sepsis, the authors tested the hypotheses that the insertion-deletion polymorphism (-94ins/delATTG) (1) alters nuclear translocation of nuclear factor-κB and activator protein-1 (NF-κB1) in monocytes after lipopolysaccharide stimulation; (2) affects lipopolysaccharide-induced NF-κB1 messenger RNA expression, tumor necrosis factor α concentrations, and tissue factor activity; and (3) may be associated with increased 30-day mortality in patients with sepsis. METHODS: Nuclear translocation of NF-κB1 in monocytes after lipopolysaccharide stimulation from healthy blood donors was performed with immunofluorescence staining (n = 5 each). Lipopolysaccharide-induced NF-κB1 messenger RNA expression was measured with real-time polymerase chain reaction (PCR; n = 60), tumor necrosis factor α concentrations with a multiplexing system kit (n = 60), and tissue factor activity with thromboelastometry (n = 105). In a prospective study, multivariate proportional hazard analysis tested 30-day mortality in patients with sepsis (n = 143). METHODS AND RESULTS: The homozygous deletion genotype compared with the homozygous insertion genotype was associated with a nearly twofold increase in nuclear translocation of NF-κB1 (P = 0.001), a threefold difference in NF-κB1 messenger RNA expression (P = 0.001), and a twofold increase in tissue factor expression (P = 0.021). The deletion allele in adults with severe sepsis was tested as an independent prognostic factor for 30-day mortality (hazard ratio, 2.3; 95% CI, 1.13-4.8; P = 0.022). Mortality was 25% for homozygous insertion genotypes but 41% for combined heterozygous deletion/homozygous deletion genotypes (P = 0.034). CONCLUSION: The deletion allele of the NFκB1 insertion-deletion (-94ins/delATTG) polymorphism is associated with increased 30-day mortality in patients with severe sepsis and increased reaction of the innate immune system. Copyright © 2012, the American Society of Anesthesiologists, Inc. Lippincott Williams & Wilkins.


Jung N.,Klinik 1 fur Innere Medizin | Seifert H.,Institute For Medizinische Mikrobiologie | Siewe J.,Klinik und Poliklinik fur Orthopadie und Unfallchirurgie | Fatkenheuer G.,Klinik 1 fur Innere Medizin
Internist | Year: 2013

Infections of the vertebra and neighboring disc create the characteristic lesions of vertebral osteomyelitis. The incidence has been estimated to range from 0.3 to 6.5 cases/100,000 persons. The hematogenous route of infection is predominant while direct inoculation through iatrogenic procedures and contiguous spread from adjacent tissue are rare. Most patients with hematogenous vertebral osteomyelitis exhibit predisposing factors, such as advanced age and diabetes mellitus. Diagnosis is often delayed due to the nonspecific nature of back pain, the main symptom. Furthermore, fever is frequently absent. Staphylococcus aureus is the most prevalent pathogen of pyogenic vertebral osteomyelitis in Europe. Magnetic resonance imaging (MRI) is the method of choice for the radiological diagnosis and blood cultures belong to the standard procedures. In cases of negative blood cultures a biopsy is generally warranted for microbiological diagnosis, either by computed tomography (CT)-guided needle biopsy or open surgery. Randomized trials that have addressed different antibiotic regimens are lacking. The recommended duration of treatment ranges from 6 weeks to 3 months. Patients with abscesses and implant devices in particular should be treated for 3 months. © Springer-Verlag Berlin Heidelberg 2013.


Desel C.,Friedrich - Alexander - University, Erlangen - Nuremberg | Werninghaus K.,Friedrich - Alexander - University, Erlangen - Nuremberg | Ritter M.,TU Munich | Jozefowski K.,Friedrich - Alexander - University, Erlangen - Nuremberg | And 9 more authors.
PLoS ONE | Year: 2013

Successful vaccination against intracellular pathogens requires the generation of cellular immune responses. Trehalose-6,6-dibehenate (TDB), the synthetic analog of the mycobacterial cord factor trehalose-6,6-dimycolate (TDM), is a potent adjuvant inducing strong Th1 and Th17 immune responses. We previously identified the C-type lectin Mincle as receptor for these glycolipids that triggers the FcRγ-Syk-Card9 pathway for APC activation and adjuvanticity. Interestingly, in vivo data revealed that the adjuvant effect was not solely Mincle-dependent but also required MyD88. Therefore, we dissected which MyD88-dependent pathways are essential for successful immunization with a tuberculosis subunit vaccine. We show here that antigen-specific Th1/Th17 immune responses required IL-1 receptor-mediated signals independent of IL-18 and IL-33-signaling. ASC-deficient mice had impaired IL-17 but intact IFNγ responses, indicating partial independence of TDB adjuvanticity from inflammasome activation. Our data suggest that the glycolipid adjuvant TDB triggers Mincle-dependent IL-1 production to induce MyD88-dependent Th1/Th17 responses in vivo. © 2013 Desel et al.


Peter-Getzlaff S.,Institute For Medizinische Mikrobiologie | Luthy J.,Institute For Medizinische Mikrobiologie | Voit A.,Institute For Medizinische Mikrobiologie | Bloemberg G.V.,Institute For Medizinische Mikrobiologie | Bottger E.C.,Institute For Medizinische Mikrobiologie
Journal of Clinical Microbiology | Year: 2010

We have recently developed a PCR assay for detection of Mycobacterium spp. at the genus level based on the Cobas Amplicor platform. The sensitivities for smear-positive and smear-negative specimens were found to be 100% and 47.9%, respectively. The specificity was 97.7%, the positive predictive value 84.6%, and the negative predictive value 93.1%. In a follow-up study, we have systematically evaluated the Mycobacterium genus assay in parallel with the Cobas Amplicor Mycobacterium tuberculosis assay on 2,169 clinical specimens, including respiratory and nonrespiratory specimens. Based on the genus assay, nontuberculous mycobacteria were readily detected and identified to the species level by PCR-mediated sequencing. In addition, our data point to a limited specificity of the Cobas Amplicor M. tuberculosis assay. Copyright © 2010, American Society for Microbiology. All Rights Reserved.


Gebhardt F.E.,Institute For Medizinische Mikrobiologie | Wantia N.,Institute For Medizinische Mikrobiologie
Medizinische Klinik - Intensivmedizin und Notfallmedizin | Year: 2013

There are numerous guidelines for the prevention of hospital-acquired infections; however, adherence to these guidelines is only limited. The bundle concept was developed to facilitate the implementation by prioritizing certain measures. A bundle contains 3-5 evidence-based key interventions. The bundle concept has been successfully applied to reduce central catheter-related bloodstream infections and ventilation-associated pneumonia whereby only strict compliance can help to reduce infections; therefore, the right implementation strategy is essential. This means accurate planning, delegation of responsibilities, education, control of compliance and infection surveillance. © 2013 Springer-Verlag Berlin Heidelberg.


Schubert A.,Universitatsklinikum Ulm | Ehlert K.,Universitatsklinikum Munster | Schuler-Luettmann S.,Institute For Medizinische Mikrobiologie | Gentner E.,Universitatsklinikum Ulm | And 2 more authors.
BMC Infectious Diseases | Year: 2013

Background: Human cytomegalovirus infections are still significant causes of morbidity and mortality in transplant recipients. The use of antiviral agents is limited by toxicity and evolving resistance in immunocompromised patients with ongoing viral replication during therapy. Here, we present the first documented case of genotypic resistance against maribavir in a bone marrow transplant (BMT) recipient.Case presentation: The female 13-year-old patient was suffering from a refractory cytopenia. Ganciclovir, foscarnet, cidofovir, leflunomide and maribavir, an inhibitor of the cytomegalovirus UL97 protein, were administered to treat a therapy-resistant cytomegalovirus infection. Viral mutations conferring resistance against nucleotide and pyrophosphate analogs as well as maribavir (MBV) have evolved sequentially. Particularly, impressive was the fast emergence of multiple mutations T409M, H411Y and H411N conferring maribavir resistance after less than 6 weeks.Conclusion: We describe the fast emergence of cytomegalovirus variants with different maribavir resistance associated mutations in a bone marrow transplant recipient treated with MBV 400 mg p.o. twice per day. The results suggest that a high virus load permitted a selection of several but distinct therapy-resistant HCMV mutants. Since a phase II study with MBV is intended for the treatment of resistant or refractory HCMV infections in transplant recipients this has to be kept in mind in patients with high viral loads during therapy (NCT01611974). © 2013 Schubert et al.; licensee BioMed Central Ltd.


Bloemberg G.V.,Institute For Medizinische Mikrobiologie | Voit A.,Institute For Medizinische Mikrobiologie | Ritter C.,Institute For Medizinische Mikrobiologie | Deggim V.,Institute For Medizinische Mikrobiologie | Bottger E.C.,Institute For Medizinische Mikrobiologie
Journal of Clinical Microbiology | Year: 2013

The Roche Cobas Amplicor MTB assay, recently replaced by the Roche Cobas TaqMan MTB assay, was one of the first commercially available assays for detection of the Mycobacterium tuberculosis complex based on nucleic acid amplification. We reported previously on the limited specificity of the Cobas Amplicor MTB assay, in particular for positive samples with an optical density at 660 nm (OD660) of <2.0. Using a selected set of respiratory samples, which were scored as false positive by the Cobas Amplicor test, we demonstrate here that the specificity of the Cobas TaqMan assay is significantly improved. In addition, our study of a set of 133 clinical samples revealed that the Cobas TaqMan MTB assay showed significantly less PCR inhibition than the Cobas Amplicor test. An overall concordance of 98.2% was observed between the two assays. In a subsequent prospective study, we evaluated the performance of the Roche Cobas TaqMan MTB assay on 1,143 clinical specimens, including respiratory (n = 838) and nonrespiratory (n = 305) specimens. Using culture as the gold standard, we found a sensitivity of 88.4% and a specificity of 98.8% for the 838 respiratory specimens, compared to a sensitivity of 63.6% and a specificity of 94.6% for the 305 nonrespiratory specimens. We conclude that the Cobas TaqMan MTB assay is a significantly improved tool for the direct detection of M. tuberculosis DNA in clinical specimens. © 2013, American Society for Microbiology.

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