Project description:The goal of this study were to compare the transcriptoms of CcpA and CovR in group A Streptococcus. Isogenic mutant strains were created in which CcpA and CovR were inactivated alone and in combination. The transcriptomes of the four strains (wild-type, CcpA mutant, CovR mutant, and ccpA-covR double mutant) were then compared.
Project description:The goal of this study were to compare the transcriptoms of CcpA and CovR in group A Streptococcus. Isogenic mutant strains were created in which CcpA and CovR were inactivated alone and in combination. The transcriptomes of the four strains (wild-type, CcpA mutant, CovR mutant, and ccpA-covR double mutant) were then compared. Four biological replicates of each strain were grown to the mid-exponential and stationary phases of growth in THY. Cells were harvested, RNA isolated, and converted to cDNA. cDNA was hybridized to a custom-made Affymetrix GeneChip that contains 100% of the ORFs of the wild-type strain MGAS2221.
Project description:This study evaluate how catabolite control protein A (CcpA) inactivation affected gene transcript levels in the group A Streptococcus serotype M1 strain MGAS5005 during growth in standard laboratory medium. Keywords: transcriptome analysis 4 replicates of strain MGAS5005 and delta_cppA were grown in THY to early and late logarithmic growth phases. The transcriptomes of each samples were then analyzed.
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.
Project description:This study evaluate how catabolite control protein A (CcpA) inactivation affected gene transcript levels in the group A Streptococcus serotype M1 strain MGAS5005 during growth in standard laboratory medium. Keywords: transcriptome analysis
Project description:We sought to determine how CovRS mutations varying CovR phosphorylation levels affect the gene expression profile of group A streptococcus
Project description:We sought to determine how deletion of ccpA affects the gene expression profile in three M serotype strains of group A streptococcus
Project description:Bacterial CRISPR-Cas9 immune systems protect against foreign DNA. However, immune efficiency is constrained by Cas9 off-target effects and toxicity. Here, we demonstrate that CRISPR-Cas9 immunity is regulated by CovR, the major regulator of virulence in Group B Streptococcus, a pathobiont responsible for neonatal invasive infections. We show that CovR binds to and represses a distal promoter of the cas operon, embedding immunity in the virulence regulatory network. Releasing CovR repression enhances immune efficiency against suboptimal spacers, originating from old immune memory or mutations, thereby transiently expanding the sequence space recognized and cleaved by Cas9. Furthermore, CovR inactivation promotes the acquisition of new spacers, enhancing immune memory. CovR-mediated immune regulation is conserved at the species level, with lineage-specific variability in the constitutive cas promoter and Cas9 variants, suggesting different evolutionary trajectories. Overall, we describe a coordinated regulatory mechanism between immunity and virulence that enhances the immune repertoire during acute infection phases.
Project description:Bacterial CRISPR-Cas9 immune systems protect against foreign DNA. However, immune efficiency is constrained by Cas9 off-target effects and toxicity. Here, we demonstrate that CRISPR-Cas9 immunity is regulated by CovR, the major regulator of virulence in Group B Streptococcus, a pathobiont responsible for neonatal invasive infections. We show that CovR binds to and represses a distal promoter of the cas operon, embedding immunity in the virulence regulatory network. Releasing CovR repression enhances immune efficiency against suboptimal spacers, originating from old immune memory or mutations, thereby transiently expanding the sequence space recognized and cleaved by Cas9. Furthermore, CovR inactivation promotes the acquisition of new spacers, enhancing immune memory. CovR-mediated immune regulation is conserved at the species level, with lineage-specific variability in the constitutive cas promoter and Cas9 variants, suggesting different evolutionary trajectories. Overall, we describe a coordinated regulatory mechanism between immunity and virulence that enhances the immune repertoire during acute infection phases.
