CONTRIBUTION OF YQIC IN SALMONELLA TYPHIMURIUM TO THE VIRULENCE IN MICE AND TEMPERATURE RESISTANCE

CARRICA M; AGUIRRE A; SABIO Y GARCÍA J; ROSSETTI O; GARCÍA VÉSCOVI E; CRAVERO S

Mar del plata

Congreso; XLIII Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2007

Socidad argentina de investigaciones bioquimicas

The gene yqiC of the pathogenic enterobacterium Salmonella typhimurium encodes for a 100-residue protein of unknown function that belongs to a highly conserved protein family inproteobacteria. This protein has homology with the virulence factor IivA of Brucella abortus . Similar to IivA, YqiC of Salmonella typhimurium has a predicted coiled-coil helix domain in the C terminal half and it displays a trimetric structure. In order to understand the relevance of yqiC in S. typhimurium virulence, a null mutant, named St-yqiC , was constructed and the virulence of this strain was assayed. St-yqiC showed a severely attenuated phenotype in BALB/c mice inoculated intraperitoneally as well as orally. This pattern was reverted when St-yqiC was complemented with the wild-type gene. On the other hand, we studied the behavior of St-yqiC in macrophage and epithelial cell lines and indifferent conditions, such as nutrients deprivation and thepresence of H O , polimixine B or SDS. St-yqiC did not display a significantly altered phenotype in any of these conditions. Interestingly, we found that yqiC was involved in temperature resistance, due to the fact that St-yqiC failed to grow at 42ºC whilethe parental and the complemented strain grew normally at this temperature. These results contribute to understand the role of yqiC in the bacteria-host interaction.