Mutants of Salmonella enterica serovar Typhimurium that lack the transcriptional regulator RfaH are efficient as live oral vaccines against salmonellosis in mice. We show that the attenuation of the vaccine candidate strain is associated with reduced net growth in epithelial and macrophage cells. In order to identify the relevant RfaH-dependent genes, the RfaH regulon was determined with S. enterica serovars Enteritidis and Typhimurium using whole-genome Salmonella microarrays. As well as impact ...[more]
Project description:Epithelial cells are the first cell type Salmonella Typhimurium will encounter when infecting a host. Using DNA array techology we identified the Salmonella enterica Typhimurium genes regulated inside human epithelial cells and their variation through time.
Project description:DNA microarrays were used to provide a global transcriptional profile of S. typhimurium during the intracellular growth phase of infection pathogenesis following infection of macrophages.
Project description:Analysis of transcriptome in a strand-specific manner to further refine previous genome annotation; RNA-seq was also combined with microarray and proteome analysis to further define the S. Typhi ompR regulon and identify novel ompR regulated transcripts.
Project description:The Sfh protein is encoded by self-transmissible plasmids involved in human typhoid and is closely related to the global regulator H-NS. We have found that Sfh provides a stealth function that allows the plasmids to be transmitted to new bacterial hosts with minimal effects on their fitness. Introducing the plasmid without the sfh gene imposes a mild H-NS- phenotype and a severe loss of fitness due to titration of the cellular pool of H-NS by the A+T-rich plasmid. This stealth strategy seems to be used widely to aid horizontal DNA transmission and has important implications for bacterial evolution.
Project description:P. profundum SS9 strain cells were grown at two different pressure conditions 0.1 MPa and at 28 MPa. RNA extracted from the two different cultures was labelled with Cy5 and Cy3 and competitively hybridized on the same slide.
Project description:NADPH dependent phagocytic oxidase, by producing hydroxyradicals such as hydrogen peroxide, is essential for host defense against Salmonella infection. We used gene array analysis to identify Salmonella enterica serovar Typhimurium genes regulated by NADPH dependent phagocytic oxidase intracellularly in comparison to those expressed in vitro by hydrogen peroxide.