REGULATION OF DIFFERENT GENE EXPRESSION UNDER Salmonella Typhimurium STRESS CONDITIONS

FABIÁN E. LÓPEZ; ANDRÉS GRAMAJO LÓPEZ; MARÍA M. PESCARETTI; ROBERTO D. MORERO; DELGADO, MONICA ALEJANDRA

San Miguel de Tucumán

Congreso; VII Congreso Argentina de Microbiología General de la Sociedad argentina de Microbiología General (SAMIGE).; 2011

Sociedad argentina de Microbiología General

Salmonella Typhimurium is an intracellular pathogen or free-living bacteria. This microorganism is able to adapt to many different microenvironments, some of whom are limited in essential nutrients for bacterial development or presented extremes physical-chemical conditions. In a previous work, we study the regulation of narZ and asr the "acid shock RNA" gene expression by the phosphorelay RcsCDB system. The narZ gene is required for bacteria survival in anaerobiosis, at low concentrations of carbon source, acid pH and thermotolerance; while the asr "acid shock RNA” gene is expressed at low pH. The goal of this work was to study the expression of the genes listed in bacterial stress conditions such as growth with low carbon source and anaerobiosis. The results of bioinformatics analysis of the selected genes promoters region revealed potential binding sites for the RcsB regulator. The analysis was conducted with lacZY fusion to chromosomal narZ and asr genes, and determined under anaerobic growth conditions. Moreover, an RcsB direct effect was confirmed using the gel shift assay. Our results show that RcsB binds to promoter regions, affecting the regulation of these genes when the regulator rcsB is present at high levels, suggesting the important role of the RcsCDB system in the bacterial stress response