Transcription profiling of Streptococcus agalactiae strains 2603V/R and 515 and CsrR or CsrS isogenic mutants to better understand the CsrRS regulon
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ABSTRACT: 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.
ORGANISM(S): Streptococcus agalactiae
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PROVIDER: E-TIGR-131 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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