How do commensals (a.k.a. normal flora, microbiota) colonize and persist in our body in the face of a healthy immune system? How do pathogens cause asymptomatic infections? Do commensals affect the ability of pathogens to establish a niche in the body? These important human health issues are largely unexplored. The goal of our lab is to understand the mechanisms underlying these microbial traits. Our work focuses on bacteria belonging to the Neisseria genus, and we use biochemistry, genetics/genomics, high-resolution microscopy and immunology to explore these issues. Our work will ultimately add to our knowledge of basic microbiology and aid in the development of vaccines and antibiotics.