Similar Datasets
Project description:The aim of this study was to investigate the response of human brain endothelial cells to bacterial (group B streptococcus, GBS) infection. Results: GBS WT strain infection results in a specific gene induction pattern that is different from the pilA mutant, but not other mutants such as pilB and srr-1. Conclusion: These findings suggest that the GBS PilA protein contributes to gene induction in brain endothelium.
2011-09-06 | E-MTAB-765 | biostudies-arrayexpress
Project description:We report the characterization of the major regulator of virulence gene expression (CovR) in Group B Streptococcus. The ChIP-seq experiments define the binding of CovR on the chromosome of the BM110 strain, a representative of the hypervirulent GBS lineage responsible of neonatal meningitis. Regulatory evolution of CovR signaling was investigated by comparing ChIP-seq done in parallel in a second GBS clinical isolate (NEM316) not belonging to the hypervirulent lineage.
2021-08-23 | GSE158046 | 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:GBS infection during pregnancy
| PRJNA807379 | ENA
Project description:The purpose of this study was to identify Group B Streptococcus (GBS) genes that are controlled by the CiaR response regulator. Deletion of the GBS ciaR gene resulted in a significant decrease in intracellular survival within neutrophils, murine macrophages, and human BMEC, which was linked to increased susceptibility to killing by antimicrobial peptides, lysozyme, and reactive oxygen species. Furthermore, competition experiments in mice showed that wild-type GBS had a significant survival advantage compared to the isogenic ciaR mutant. Microarray analysis comparing gene expression between the wild-type and ciaR mutant strains revealed several CiaR-regulated genes that may contribute to GBS stress tolerance and subversion of host defenses.
2009-01-22 | GSE14259 | GEO
Project description:Group B Streptococcus (GBS), in its transition from commensal to pathogen, will encounter diverse host environments and thus require coordinately controlling its transcriptional responses to these changes. This work was aimed at better understanding the role of two component signal transduction systems (TCS) in GBS pathophysiology through a systematic screening procedure. We first performed a complete inventory and sensory mechanism classification of all putative GBS TCS by genomic analysis. Five TCS were further investigated by the generation of knock-out strains from WT strain CJB111, and in vitro transcriptome analysis identified genes regulated by these systems.
2014-06-03 | E-MTAB-2423 | biostudies-arrayexpress
Project description:The purpose of this study was to identify Group B Streptococcus (GBS) genes that are controlled by the CiaR response regulator. Deletion of the GBS ciaR gene resulted in a significant decrease in intracellular survival within neutrophils, murine macrophages, and human BMEC, which was linked to increased susceptibility to killing by antimicrobial peptides, lysozyme, and reactive oxygen species. Furthermore, competition experiments in mice showed that wild-type GBS had a significant survival advantage compared to the isogenic ciaR mutant. Microarray analysis comparing gene expression between the wild-type and ciaR mutant strains revealed several CiaR-regulated genes that may contribute to GBS stress tolerance and subversion of host defenses. Two cultures each of the wild-type GBS strain (COH1) and the isogenic ciaR mutant were grown in Todd-Hewitt broth to an optical density of 0.3. Cells were disrupted by shaking with glass beads and RNA was isolated by a Trizol method. A custom Affymetrix chip with a design based on the COH1 genomic sequence was used to analyze gene expression.
2009-01-22 | E-GEOD-14259 | biostudies-arrayexpress
Project description:Group B Streptococcus (GBS) is a leading cause of infant sepsis worldwide. Colonization of the gastrointestinal tract is a critical precursor to late-onset disease in exposed newborns. Neonatal susceptibility to GBS intestinal translocation stems from intestinal immaturity; however, the mechanisms by which GBS exploits the immature host remain unclear. β-hemolysin/cytolysin (βH/C) is a highly conserved toxin produced by GBS capable of disrupting epithelial barriers. However, its role in the pathogenesis of late-onset GBS disease is unknown. Our aim was to determine the contribution of βH/C to intestinal colonization and translocation to extraintestinal tissues. Using our established mouse model of late-onset GBS disease, we exposed animals to GBS COH-1 (WT), a βH/C-deficient mutant (KO), or vehicle control (PBS) via gavage. Blood, spleen, brain, and intestines were harvested 4 days post-exposure for determination of bacterial burden and isolation of intestinal epithelial cells. We used RNA-sequencing to examine the transcriptomes and performed gene ontology enrichment and KEGG pathway analysis. A separate cohort of animals were followed longitudinally to compare colonization kinetics and mortality between WT and KO groups. We demonstrate that disseminated to extraintestinal tissues occurred only in the WT exposed animals. We observed major transcriptomic changes in the colon of colonized animals, but not in the small intestine. We noted differential expression of genes among WT and KO exposed mice indicating that βH/C contributes to alterations in epithelial barrier structure and immune response signaling. Overall, our results demonstrate an important role for βH/C in the pathogenesis of late-onset GBS disease.
2023-05-31 | GSE230856 | GEO
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: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. Two separate RNA samples were extracted for each condition. One flip-dye replicate (2 hybridizations) was obtained for each pair of RNA samples for 4 hybridizations total.
2012-11-18 | E-GEOD-14571 | biostudies-arrayexpress