Project description:Transcriptional profiling in vivo in bovine secretory tissue from healthy (H) mammary gland and during infections with coagulase-negative Staphylococci (CoNS) and coagulase-positive Staphylococci (CoPS). The aim of this study was to examinate the global gene expression profiles of mammary gland tissues of infected and healthy (control) cows.
Project description:Transcriptional profiling in vivo in bovine secretory tissue from healthy (H) mammary gland and during infections with coagulase-negative Staphylococci (CoNS) and coagulase-positive Staphylococci (CoPS). The aim of this study was to examinate the global gene expression profiles of mammary gland tissues of infected and healthy (control) cows. Transcriptomes were compared of in the mammary glands of Holstein Friesian cows in two experiments, (H) vs (CoNS) cows and (H) vs (CoPS).
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
2017-01-06 | GSE85265 | GEO
Project description:Investigation of Resistance Profiles of Multidrug-Resistant Coagulase-Negative-Staphylococci
Project description:Purpose: The aim of the study was to compare the miRNA expression in non-infected (H) mammary gland parenchyma samples with that of glands infected with coagulase-positive staphy lococci (CoPS) or coagulase-negative staphylococci (CoNS) using next-generation sequencing. Methods: miRNA-seq analysis was performed on mammary gland parenchyma samples collected from non-infected cows and those infected with coagulase-positive or -negative staphylococci. The miRNA libraries were constructed from total RNA using NEBNext Multiplex Small RNA Library Prep Set for Illumina (New England Biolabs) according to the manufacturer protocol. The quantification of the obtained libraries was performed on a Qubit 2.0 spectrophotometer (Invitrogen, Life Technologies), while a quality control on a TapeStation 2200 instrument (D1000 ScreenTape; Agilent). Single-end cycle sequencing was performed on the HiScanSQ platform (Illumina) with the use of TruSeq SR Cluster Kit v3- CBOT-HS and TruSeq SBS Kit v 3 - HS (Illumina). MicroRNA differentially expressed between investigated groups were identified with the DESeq2 software. Results: Comparing the CoPS and H groups, 256 known and 260 potentially new miRNAs were identifed, including 32 that were diferentially expressed (p≤0.05), of which 27 were upregulated and 5 downregulated. Comparing the CoNS and H groups, 242 known and 171 new unique miRNAs were identifed: 10 were upregulated (p≤0.05), and 2 downregulated (p≤0.05). Comparing CoPS with H and CoNS with H, 5 Kyoto Encyclopedia of Genes and Genomes pathways were identifed; in both comparisons, diferentially-expressed miRNAs were associated with the bacterial invasion of epithelial cells and focal adhesion pathways. Four gene ontology terms were identifed in each comparison, with 2 being common to both immune system processes and signal transduction. Conclusions: Obtained results enabled us to characterize the miRNA profile of the mammary gland parenchyma tissue, not only the healthy one but also the tissue infected with coagulase-positive and negative staphylococci as well as allowed identification of miRNAs differing the examined groups and characteristic for the staphylococci infection. They also indicated that miRNAs, especially miR-99 and miR-182, play an essential role in the epigenetic regulation of a range of cellular processes, including immunological systems bacterial growth in dendritic cells and disease pathogenesis (miR-99), DNA repair and tumor progression (miR-182).