Project description:Manuscript title: Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes. Macrophages and neutrophils release free zinc to eliminate phagocytosed bacterial pathogens. The study investigates the effect of how zinc toxicity affects Streptococcus pyogenes. Therefore, a microarray analysis was performed in S. pyogenes cells to determine gene expression changes when exposed to high levels of zinc. We discovered that a pathway involved in tagatose-6-phosphate metabolism was upregulated when the cells are under zinc stress.
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: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:Pasteurella multocida is a Gram-negative capsulated bacterium responsible for a range of diseases that cause severe morbidity and mortality in livestock animals. The hyaluronic acid (HA) capsule produced by P. multocida serogroup A strains is a critical virulence factor. In this study, we utilised transposon-directed insertion site sequencing (TraDIS) to identify genes essential for in vitro growth of P. multocida, and combined TraDIS with discontinuous density gradients (TraDISort) to identify genes required for HA capsule production and regulation in this pathogen. Analysis of mutants with a high cell density phenotype, indicative of the loss of extracellular capsule, led to the identification of 69 genes important for capsule production. These genes included all previously characterized genes in the capsule biosynthesis locus, and fis and hfq that encode known positive regulators of P. multocida capsule. Many of the other capsule-associated genes identified in this study were involved in regulation or activation of the stringent response, including spoT and relA that encode proteins that regulate the concentration of guanosine alarmones. Disruption of the autoregulatory domains in the C-terminal half of SpoT using insertional mutagenesis resulted in reduced expression of capsule biosynthesis genes and an acapsular phenotype. Overall, these findings have greatly increased the understanding of hyaluronic acid capsule production and regulation in P. multocida.
Project description:Rgg-dependent transcriptional regulation in SF370 Streptococcus pyogenes strain was analyzed during post-exponential phase of growth Keywords: rgg mutant
