Similar Datasets
Project description:The CiaRH and LiaFSR two-component regulatory systems in Streptococcus agalactiae (Group B Streptococcus, GBS) are essential mediators of the organism s response to biologically important sources of environmental stress, and positive regulators of GBS virulence. Transcriptional profiling of CiaR mutant GBS and LiaR mutant GBS reveals that LiaR is positively-regulated by CiaR, and the individual mutant transcriptomes share a number of commonly-regulated genes. To determine the GBS response to loss of both of these key regulatory systems, we constructed a GBS mutant strain with non-polar deletions in both ciaR and liaR, and performed transcriptional profiling using DNA microarray analysis, comparing wild-type GBS to CiaR/LiaR double mutant GBS under non-stressed conditions.
2012-11-18 | GSE14572 | GEO
Project description:Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. We interrogated host-pathogen dynamics in a novel murine GDM model of GBS colonization and perinatal transmission. GDM mice had greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing revealed differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM disruption of immunity included reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered vaginal cytokines. Lastly, we observed distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Our translational model of GBS perinatal transmission in GDM hosts recapitulates several clinical aspects and enables discovery of host and bacterial drivers of GBS perinatal disease.
2023-07-05 | GSE236335 | GEO
Project description:CsrRS is a two-component regulatory system that controls expression of multiple genes and affects virulence in group B Streptococcus (GBS), a major cause of neonatal sepsis and of invasive infection in chronically ill adults. To better understand the CsrRS regulon and its importance in GBS pathogenicity, we used GBS genomic microarrays to compare global gene expression in GBS strains 2603V/R and 515 with that in CsrR or CsrS isogenic mutants. These results and comparison with data reported previously for GBS strain NEM316 demonstrated a conserved CsrRS regulon of approximately 30 genes including those encoding beta-hemolysin, CAMP factor, and C5a-peptidase, as well as a variable repertoire of genes regulated in one or two of the three strains. Inactivation of CsrS had a similar but weaker effect at most regulated loci, but, in some cases, resulted in more pronounced or divergent regulation compared to CsrR. We conclude that CsrRS regulates a core group of genes including important virulence factors in diverse strains of GBS, but also displays marked variability in the repertoire of regulated genes and in the relative effects of CsrS signaling on CsrR-mediated gene regulation. Such variation is likely to play an important role in strain-specific adaptation of GBS to particular host environments and pathogenic potential in susceptible hosts.
2008-11-25 | E-TIGR-131 | biostudies-arrayexpress
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) is a leading cause of early-onset neonatal bacterial infection. Evasion of innate immune defenses is critical to neonatal GBS disease pathogenesis. Effectors of the innate immune system such as antimicrobial peptides, as well as numerous antibiotics, target the peptidoglycan layer of the gram positive bacterial cell wall. The intramembrane-sensing histidine kinase class of two-component regulatory systems has recently been identified as important to the gram-positive response to cell wall stress. We identified and characterized the GBS homolog of LiaR, the response regulator component of the LiaFSR system and constructed site-directed, non-polar deletion mutations in the regulator gene liaR. GBS LiaR deletion mutant strains are more susceptible to cell wall active antibiotics (vancomycin and bacitracin) as well as antimicrobial peptides (colistin, nisin and the human cathelicidin LL-37) compared to isogenic wild-type GBS. LiaR mutant GBS are significantly attenuated in mouse models of both GBS sepsis and GBS pneumonia. To determine the genes regulated by LiaR that account for these defects, transcriptional profiling was performed using DNA microarray analysis, comparing wild-type GBS to LiaR mutant GBS under non-stressed conditions.
2012-11-18 | GSE14571 | GEO
Project description:Regulation of gene expression in response to variable and often adverse environmental conditions is an essential component of microbial pathogenesis. We identified the two-component regulatory system CiaRH in a screen for genes essential for the survival of Streptococcus agalactiae (Group B Streptococcus, GBS) on exposure to in vitro models of environmental stress. We constructed site-directed, non-polar deletion mutations in the regulator gene ciaR and compared the growth of CiaR mutant GBS to wild-type GBS under stressed conditions. CiaR mutant GBS are more sensitive than wild-type GBS to elevated temperature, low pH, chemical mutagens and ultraviolet light; the mutants are also more sensitive to cell-wall active antibiotics and antimicrobial peptides. CiaR mutant strains are markedly attenuated in a mouse model of GBS sepsis. To determine the genes regulated by CiaR that account for these defects, transcriptional profiling was performed using DNA microarray analysis, comparing wild-type GBS to CiaR mutant GBS under non-stressed conditions.
2012-11-18 | GSE14569 | GEO
Project description:Streptococcus agalactiae (Group B Streptococcus, GBS) can colonize the human vaginal tract leading to both superficial and serious infections in adults and neonates. To study bacterial colonization of the reproductive tract in a mammalian system, we employed a murine vaginal carriage model. Using RNASeq, the transcriptome of GBS growing in vivo during vaginal carriage was determined. Over one-quarter of the genes in GBS were found to be differentially regulated during in vivo colonization as compared to laboratory cultures. A two-component system (TCS) homologous to the staphylococcal virulence regulator SaeRS was identified as being up-regulated in vivo. One of the SaeRS targets, pbsP, a proposed GBS vaccine candidate, was shown to be important for colonization of the vaginal tract. A component of vaginal lavage fluid acted as a signal to turn on pbsP expression via SaeRS. These data demonstrate the ability to quantify RNA expression directly from the murine vaginal tract and identify novel genes involved in vaginal colonization by GBS. They also provide more information about the regulation of an important virulence and colonization factor of GBS, pbsP, by the TCS SaeRS.
2018-02-06 | GSE109680 | GEO
Project description:The underlying change of gene network expression of Guillain-Barre syndrome (GBS) remains elusive. We sought to identify GBS-associated gene networks and signalling pathways by analyzing the transcriptional profile of leukocytes in the patients with GBS.
2011-07-28 | GSE31014 | GEO
Project description:Genome wide expression profiling was used to identify signifnificantly changed genes in fetal membranes after GBS treatment Genome-wide expression profiles in GBS-inoculated human extraplacental membranes in vitro were used to identify transcriptomic pathways altered by GBS . Using bioinformatics analysis of these expression profiles we aimed to test our hypothesis that GBS activates pathways related to inflammation and premature birth in human extraplacental membranes.
2018-01-18 | GSE96557 | GEO