GLOBAL TRANSCRIPTIONAL ANALYSIS OF SALMONELLA ADAPTATION TO INCREASED LEVELS OF COPPER AND ZINC

SCAMPOLI, N. L.; PONTEL, L. B.; CHECA, S. K.; SONCINI, F. C.

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular; 2012

Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular

Salmonella is a highly prevalent food-borne pathogen. The understanding of how Salmonella modulate its gene expression repertoire to survive and replicate within host tissues is of particular relevance for human health. Transition metals such as copper and zinc are essential due to their requirement as cofactors in different metabolic processes. However, they also can be toxic even at low concentration, and bacteria have developed homeostatic systems to control their uptake and release. Recent studies have suggested that this control plays a critical role in virulence. We investigated the transcriptional response of Salmonella to these metal ions both in rich and minimal medium, using a customized whole-genome tiling arrays analysis. Groups of genes were clustered according to their behavior in the presence or absence of these metal ions. Regulation of expression of each individual gene was confirmed by both, RT-qPCR and lacZ-reporter assays, and minimum inhibitory concentration tests were performed to  investigate their role in metal-ion homeostasis. Overall, these analyses allowed us to identify novel copper and zinc regulated genes and to uncover an effect of these metal ions on other previously described stimulons. This information reveals a complex regulatory interplay between different metal-ions and their homeostasis in bacteria.