Construction of mutant strains of Salmonella enterica Typhimurium for genes encoding DNA-binding proteins: evaluation of phenotypic characteristics

Abstract

Recent data from our group indicate that null mutants of Salmonella enterica Typhimurium for genes encoding Naps (nucleoid-associated proteins) are attenuated for virulence and capable of inducing protection in murine model of infection. These results suggest a significant role of different Naps in the bacterial virulence. Based on these previous results, the goal of this project is to investigate the biological role of other genes encoding Naps in S. enterica Typhimurium. This will be achieved through phenotypic analysis of mutants such as growth in vitro and survival under nutritional stress and acidic conditions beside the ability of invasion and survival in macrophages. Furthermore, attenuation of virulence in vivo will be evaluated by using the murine model of infection. Mutants that present attenuation of virulence (at least 3 or more log differences in LD50 (lethal dose 50) compared to the wild type strains) will be assessed for induction of protection to salmonellosis in the same infection model.