I study environmental survival, transmission and pathogenesis of the important human pathogen Vibrio cholerae, the causative agent of the diarrheal-disease cholera. V. cholerae experiences fluctuating environmental conditions in aquatic habitats and during infection of human hosts, and uses two-component signal transduction systems (TCS) to monitor its environment. My work focuses on a previously uncharacterized TCS (RvvAB) of V. cholerae that inversely regulates biofilm formation and virulence, two processes critical for the transmission and infectivity of V. cholerae. I hypothesize that this TCS is involved in sensing and responding to host environmental signals that V. cholerae encounters during infection to positively govern virulence and adaptation to host environment. My project aims to identify the signals activating the RvvAB TCS and uncover the specific mechanism by which it contributes to V. cholerae pathogenesis. As TCSs are not found in humans, they represent a promising target for the development of anti-bacterial strategies. Thus, new insights gained from my studies may lead to the development of new treatment strategies for cholera.