Project description:We sequenced mRNA from three independent biological replicates of Staphylococcus epidermidis biofilms with different proportion of dormant cells. Whole trancriptome analysis of Staphylococcus epidermidis biofilms with prevented and induced dormancy.
Project description:Bacterial sepsis is a major killer in hospitalized patients. Coagulase-negative staphylococci (CNS) with the leading species Staphylococcus epidermidis are the most frequent causes of nosocomial sepsis, with most infectious isolates being methicillin resistant. However, which bacterial factors underlie the pathogenesis of CNS sepsis is unknown. While it has been commonly believed that invariant structures on the surface of CNS trigger sepsis by causing an over-reaction of the immune system, we show here that sepsis caused my methicillin-resistant S. epidermidis is to a large extent mediated by the methicillin resistance island-encoded peptide toxin, PSM-mec. PSM-mec contributed to bacterial survival in whole human blood and resistance to neutrophil-mediated killing, and caused significantly increased mortality and cytokine expression in a mouse sepsis model. Furthermore, we show that the PSM-mec peptide itself, rather than the regulatory RNA in which its gene is embedded, is responsible for the observed virulence phenotype. While toxins have never been clearly indicated in CNS infections, our study shows that an important type of infection caused by the predominant CNS species, S. epidermidis, is mediated to a large extent by a toxin. Of note, these findings suggest that CNS infections may be amenable to virulence-targeted drug development approaches. We used microarrays to detail the global gene expression between S. epidermidis strain Rp62A and S. epidermidis strain Rp62A isogenic Δpsm-mec deletion mutants
Project description:Staphylococcus aureus Newman and Staphylococcus epidermidis Tu3298, 20 minutes post challenge with sub-inhibitory concentration of sapienic acid vs equivalent concentration of ethanol. Challenge was added at mid logarithmic growth (OD600 0.5). Biological triplicates of samples were sequenced.
Project description:We examined the differential gene expression of Staphylococcus epidermidis and Staphylococcus epidermidis in dual species biofilms. Therefore, we performed RNA-Seq on single and dual species biofilms and we compared the gene expression levels in dual species biofilms to those in single species biofilms.
Project description:We use the zebrafish embryo model to study the innate immune response against Staphylococcus epidermidis. Therefore, we injected S. epidermidis into the yolk at 2 hpf and took samples at 5 days post injection.
Project description:We sequenced mRNA from three independent biological replicates of Staphylococcus epidermidis biofilms with different proportion of dormant cells.
Project description:We performed differential RNA-seq of two Staphylococcus epidermidis clinical isolates (PS2 and PS10) to compare their transcription profiles. The isolates were originally obtained from blood cultures during a systemic infection in an immunocompromised patient (Weisser et al. 2010. J Clin Microbiol 48: 2407-2412). They are of clonal origin, but differ phenotypically with respect to extracellular biofilm matrix production. Thus PS2, isolated in the early stage of the infection, forms a weak biofilm mediated by protein-protein interactions, while PS10, which was obtained at the end of the infection course, forms a strong biofilm through production of a polysaccharide intercellular adhesin (PIA) extracellular biofilm matrix. Transcription profiling by dRNA-seq was performed to elucidate differentially expressed metabolic pathways and regulators contributing to the switch in extracellular biofilm matrix producction between the two isolates.
