Project description:Investigation of baseline transcription activity of two different clinical isolates of Staphylococcus aureus with two different susceptibility levels to the antibiotics Vancomycin and Daptomycin.
Project description:Investigation of baseline transcription activity of two different clinical isolates of Staphylococcus aureus with two different susceptibility levels to the antibiotics Vancomycin and Daptomycin. Two different strains of Staphylococcus aureus, one that is fully Vancomycin and Daptomycin Sensitive and one with decreased Vancomycin and Daptomycin Sensitivity - grown to mid-log phase in rich broth.
Project description:The purpose of this study was to compare the global, growth phase-dependent transcriptional profiles of two isolates of Staphylococcus aureus. One isolate is a prototypic laboratory strain named RN6390, and has been used frequently as a model organism for study of staphylococcal physiology and virulence. However, recent studies indicate that RN6390 is not, in general, genotypically or phenotypically representative of clinical isolates of Staphyloccos aureus. Therefore, there is no current comprehensive picture of gene expression patterns in a virulent, clinical isolate of Staphyloccous aureus. For these reasons, we compare the transcriptional profile of RN6390 to that of a virulent clinical isolate, UAMS-1. Also included in this study is profiling of two UAMS-1 regulatory mutants, UAMS-155, and UAMS-929. These strains possess mutations in the accessory gene regulator (agr) and staphylococcal accessory regulator (sarA) genes, respectively. These two genes are well described global regulatory molecules that are reported to play important roles in controlling virulence factor production and biofilm formation in Staphylococcus aureus. However, most study of these two molecules has been limited to laboratory strains such as RN6390. For these reasons, this study also includes transcriptional profiling of UAMS agr and sarA mutants. Keywords: Comparative, growth phase-dependent transcriptional profiling of bacterial strains and isogenic regulatory mutants
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.
