The Mekalanos laboratory is engaged in the analysis of bacterial virulence and functional genomics. The goal of these studies is to understand how pathogenic bacteria grow, evade the host immune system and ultimately cause disease. A variety of organisms are currently studied in the laboratory including several Vibrio species and Pseudomonas aeruginosa. Our research encompasses many topics, including: 1) how bacteria sense their environment and modulate the expression of virulence genes, 2) the mechanism of horizontal gene transfer in the evolution of pathogenic strains, 3) how genomic information can be used to identify virulence factors, antigens, and gene products that are essential for cell growth, 4) ecological factors that control emergence and endemic properties of bacterial pathogens, 5) the biochemical function of bacterial virulence factors including protein secretion organelles that display dynamic activity which can be imaged in real time. We use genetic, genomic, proteomic, biochemical, structural, imaging and chemical biological approaches to explore these topics. Where possible, the knowledge gained in our studies is applied to the development of more effective vaccines and small molecule therapeutics.