Project description:In Streptococcus pyogenes, mutation of GidA results in avirulence despite the same growth rate as the wild type. To understand the basis of this effect, global transcription profiling was conducted. Keywords: Wild type vs. GidA mutant Streptococcus pyogenes
Project description:In Streptococcus pyogenes, mutation of the peroxide sensor PerR results in avirulence despite producing hyper-resistance to peroxide stress. To understand the basis of this effect, global transcription profiling was conducted. Keywords: Study of the regulation of gene expression by PerR
Project description:Whole genone expression profile comparing wild-type NZ131 to serR deletion mutant, grown in C-medium Mutants and interpretation are described further in the manuscript to be submitted: LaSarre and Federle, 2010. Title: Regulation and Consequence of Serine Catabolism in Streptococcus pyogenes. A two chip study using total RNA recovered from three separate wild-type cultures of Streptococcus pyogenes NZ131 and three separate mutant cultures of Streptococcus pyogenes NZ131 seR-, pooled following RNA extraction
Project description:Whole genone expression profile comparing wild-type NZ131 to serR deletion mutant, grown in C-medium Mutants and interpretation are described further in the manuscript to be submitted: LaSarre and Federle, 2010. Title: Regulation and Consequence of Serine Catabolism in Streptococcus pyogenes.
Project description:Transcriptional profile of Streptococcus pyogenes stk mutant strain JRS2516 vs its wild type parent strain MGAS2221 The RNA prepared from triplicate cultures for the wild type and the stk mutant strains was each labeled with Cy3 and hybridized to duplicate arrays. Reference RNA consisted of pooled RNA for the wild type and stk mutant, labeled with Cy5.
Project description:Group A Streptococcus (GAS, aka Streptococcus pyogenes) causes an array of human diseases from mild pharyngitis to life-threatening necrotizing fasciitis. Invading host cells is a strategy for GAS to avoid antibiotic killing and immune system clearance. Our previous study showed that GAS is able to multiply in human microvascular endothelial cell line-1 (HMEC-1), and has higher survival in HMEC-1 cells due to insufficient acidification in lysosomes. GAS peroxide response regulator (PerR) modulates not only peroxide stress, but also metal homeostasis and bacterial virulence. Therefore, we aimed to investigate the role of PerR during GAS invading endothelial cells. First, we found that ΔperR mutant was more tolerant to H2O2 in vitro using hydrogen peroxide sensitivity assay. We further used cDNA-qPCR analysis to clarify the resistance mechanism of ΔperR mutant. The gene expressions of dpr, ahpC, and ahpF were up-regulated, explaining the enhanced resistance of the ΔperR mutant against peroxide stress. However, the proliferation of the ΔperR mutant in HMEC-1 cells was significantly lower than wild type strain after 5 h post-infection. To explore the underlying mechanisms of ΔperR mutant during infection, we performed dual RNAseq analysis to identify differentially expressed genes, and validated them using cDNA-qPCR analysis. The resulting up-regulated genes of iron efflux pump pmtA, iron/zinc chelating protein dpr, and zinc acquisition system (adcA, lmb/adcAII, phtD), and down-regulated zinc efflux pump czcD gave rise to impaired metal homeostasis in the ΔperR mutant. Furthermore, in vitro growth curve assays showed that the ΔperR mutant was sensitive to zinc deficiency and resistant to zinc toxicity. Taken together, this study has demonstrated the critical roles that GAS PerR plays in protecting from peroxide stress of host innate immune responses and zinc sequestration of nutritional immunity. Our novel findings open a new avenue of strategies in the development of antimicrobial agents. Our study demonstrates the importance of PerR. It aids GAS virulence in immune evasion during the LC3-associated phagocytosis in endothelial cells.
Project description:Rgg-dependent transcriptional regulation in SF370 Streptococcus pyogenes strain was analyzed during post-exponential phase of growth Keywords: rgg mutant Microarray analysis was performed using RNA samples isolated from both wild-type SF370 and SF370 rgg mutant strains during post-exponential phase of growth
