Salmonella enterica Serovar Typhimurium

Using signature-tagged mutagenesis, a mutation in the poxR gene of Salmonella enterica serovar Typhimurium was identified with decreased survival in an ex vivo swine stomach content assay(Bearson et al. Appl Environ Microbiol. 72:2829- 36). Gastrointestinal colonization and fecal shedding of the poxR mutant in swine was also significantly reduced compared to the parental wild-type strain chi4232 (109th General Meeting of the American Society for Microbiology, 2009). Additionally, a phenotypic microarray comparison of the poxR mutant and parental strain revealed numerous phenotypic alterations, including increased sensitivities of the poxR mutant to antimicrobials, detergents and toxic cations. As a putative lysyl-tRNA synthetase, the elevated susceptibility of the poxR mutant to these various environments could be due to altered protein production compared to the wild-type strain. Therefore, two dimensional gel analysis was conducted to investigate observed in the wild-type strain that were either not present or greatly diminished in the poxR mutant. Furthermore, over 20 proteins were detected in the poxR mutant that were absent in the wild-type strain. Investigation of these differentially produced proteins may identify gene products that are critical for survival of Salmonella during environmental stress and host colonization, thereby providing targets for intervention strategies against Salmonella infection. the protein profiles of the mutant and wild-type strains. At mid-logarithmic phase growth, 15 proteins were