Epidemiological evidence indicates that microbial biofilms play a role in indwelling device-associated bloodstream and urinary tract infections. However, direct evidence supporting this claim is lacking in most cases. The Gram-positive opportunistic pathogen Enterococcus faecalis is frequently implicated as a causative agent of urinary tract infections, bacteremia, and bacterial endocarditis. Each of these types of infections has been associated with organisms growing as a biofilm. E. faecalis is often isolated from biofilms on various indwelling devices. These observations lead to the hypothesis that biofilm growth is an important mechanism by which E. faecalis is able to persist in vivo and cause infection. The goal of this proposal is to evaluate the contribution of biofilm growth to E. faecalis persistence and proliferation in animal models of infection. The following approaches will be taken: identify the genes involved in biofilm formation, examine the regulation of those genes during biofilm development, analyze gene expression in biofilms grown in vivo, and assess mutants impaired in biofilm formation in in vivo models of infection.
