ACE and endocarditis: In the present study, we have studied the role of Ace in the pathogenesis of E. faecalis endocarditis by generating an ace deletion mutant in E. faecalis strain OG1RF, by complementing this mutant (OG1RFΔace), by comparing these isogenic strains with OG1RF for adherence to various extracellular matrix (ECM) proteins and for their ability to infect aortic valves in a rat endocarditis model.