Our research focuses on understanding the mechanisms used by bacteria to adapt and survive in diverse environments. Current targets of investigation in our group are the environmental bacteria Legionella pneumophila and Serratia marcescens. L. pneumophila is a parasite of freshwater protozoa and has a unique intracellular biphasic lifecycle that alternates between replicative forms and cyst forms. Normally intended for prolonged survival between protozoan hosts, cyst forms can also cause a pneumonia termed Legionnaires’ disease in susceptible humans. S. marcescens is also an opportunistic human pathogen known for multidrug resistance gained through modulation of its bacterial physiology and horizontal gene transfer. To carry out our investigations, we use a diverse range of molecular biology approaches.