(489n) Coordinate Regulation of Virulence in Salmonella Typhimurium

Salmonella typhimurium is a common food-borne pathogen that causes a variety of diseases ranging from mild gastroenteritis to life threatening systemic infections. While the mechanism for invasion is still not known, a number of systems are known to be involved. These include motility, adhesion, and protein secretion. In this talk, we will discuss the role of three interacting systems involved in invasion: motility, type I fimbriation, and the type III secretion system encoded within Salmonella pathogenicity island 1 (SPI1). We have previously investigated the regulation of each system in isolation. Here, we will discuss how these three systems are coordinately regulated during invasion. Using a combination of modeling and experimental approaches, we investigated how these three systems are jointly regulated. In particular, we have identified the role of the regulators that mediate this dynamic crosstalk. Based on these results, we demonstrate that this regulation ensures that these three systems are temporally activated in a strict hierarchy during invasion.