The long-term objective of my research is to identify and characterized virulence determinants that contribute to the pathogenic potential of the B. burgdorferi. Through the utilization of in vivo bioluminescence we are evaluating the kinetics of borrelial infectivity in various strains or mutant derivatives that exhibit distinct phenotypes. We are also tracking how in vivo synthesis of critical virulence determinants affects B. burgdorferi colonization and dissemination. This work will contribute to the current body of knowledge by shedding light on the pathogenic and temporal role of specific borrelial genes during the infectious process.