Induction of adaptive changes in the Streptococcus agalactiae transcriptome by human blood
Ontology highlight
ABSTRACT:
ORGANISM(S): Streptococcus agalactiae
PROVIDER: GSE11705 | GEO | 2008/11/01
SECONDARY ACCESSION(S): PRJNA106119
REPOSITORIES: GEO
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Project description:In the present investigation, we conducted a bacterial transcriptome dynamics analysis during GBS incubation with human blood. We observed a large modification in the expression of genes involved in transcriptional regulation and in the metabolism of carbohydrates, purins/pyrimidins and inorganic ions, and an up-regulation of genes involved in attachment and plasminogen contact. We also observed differences in the expression of GBS genes in blood at 40° relative to 37°C. The serotype III GBS reference strain NEM316 was cultivated in Todd Hewitt broth supplemented with 0.2% yeast extract (THY) in 5% CO2 at 37°C until OD reached 0.7. Culture was harvested by centrifugation 8 minutes at 4000 x g at 37°C, then suspended in phosphate-buffered saline (PBS). Fresh heparinized human blood was obtained from seven healthy voluntary donors (four males and three females) in accordance with a protocol approved by the Institutional Review Board of the Methodist Hospital Research Institute. The blood was maintained at 37°C no more than one hour prior to use. Bacterial suspension was then incubated with the blood of each donor at 37°C and 40°C under slight rotation to avoid sedimentation of blood and bacterial cells (the volume of blood was equivalent to the volume of bacterial culture prior to centrifugation). Samples were removed for microarrays analysis immediately after adding bacteria, and after 30 and 90 minutes of incubation. Thus, for each of the seven blood donors, we obtained results for five time points: immediately after mixing the bacterium with the blood (time 0), after 30 minutes of contact with blood (time 1) at 37°C and 40°C, and after 90 minutes of contact with blood (time 2) at 37°C and 40°C.
2008-10-31 | E-GEOD-11705 | biostudies-arrayexpress
Project description:In the present investigation, we conducted a bacterial transcriptome dynamics analysis during GBS incubation with human blood. We observed large modification in the expression of numerous genes, but GBS transcriptome was different with the blood of one donor. More genes were up-regulated and less down-regulated in respect to the other donors.
2009-06-01 | GSE12201 | 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: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:In the present investigation, we conducted a bacterial transcriptome dynamics analysis during GBS incubation with human blood. We observed large modification in the expression of numerous genes, but GBS transcriptome was different with the blood of one donor. More genes were up-regulated and less down-regulated in respect to the other donors. The serotype III GBS reference strain NEM316 was cultivated in Todd Hewitt broth supplemented with 0.2% yeast extract (THY) in 5% CO2 at 37°C until OD reached 0.7. Culture was harvested by centrifugation 8 minutes at 4000 x g at 37°C, then suspended in phosphate-buffered saline (PBS). Fresh heparinized human blood was obtained from one healthy volunteer in accordance with a protocol approved by the Institutional Review Board of the Methodist Hospital Research Institute. The blood was maintained at 37°C no more than one hour prior to use. Bacterial suspension was then incubated with theblood at 37°C and 40°C under slight rotation to avoid sedimentation of blood and bacterial cells. Samples were removed for microarrays analysis immediately after adding bacteria, and after 30 and 90 minutes of incubation. Thus, we obtained results for five time points: immediately after mixing the bacterium with the blood (time 0), after 30 minutes of contact with blood (time 1) at 37°C and 40°C, and after after 90 minutes of contact with blood (time 1) at 37°C and 40°C.
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2012-11-18 | GSE14573 | 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
Project description:The human-derived serotype Ⅴ ST1 GBS strains NNA038 and NNA048 was isolated from a amniotic fluid of full-term pregnant woman who suffered from premature rupture of membrane in China.Serotype Ia ST7 GBS strain YM001 is an attenuated strain ,its parent strain HN016 was isolated from an outbreak epidemical disease in tilapia from China.HN016_KO_D2 is a knockout strain from Serotype Ia ST7 GBS strain HN016.
2019-11-12 | PXD011206 | Pride
Project description:Streptococcus agalactiae (Lancefield’s group B Streptococcus, GBS) is a major bacterial species of genus Streptococcus and has medical and veterinary importance by affecting mainly humans (Maione et al., 2005; Johri et al., 2006), cattle (Keefe, 1997) and fish (Mian et al., 2009). The GBS is the most important pathogen for the Nile tilapia, a global commodity of the aquaculture sector, causing outbreaks of septicemia and meningoencephalitis (Hernández et al., 2009; Mian et al., 2009). This study aimed to evaluate the global abundancy of proteins among the main genotypes of GBS isolated from fish identified in Brazil using a label free shotgun liquid chromatography-ultra definition mass spectrometry (LC-UDMSE) approach and to compare the differential expression of proteins identified between isolates from fish and human.
2019-01-14 | PXD008744 | Pride
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