Mechanisms of resistance to penicillins in Enterococcus faecalis

Penicillins are commonly used in the treatment of a wide range of infections and are often used for therapy in patients with urinary tract infections. Enterococcus faecalis is susceptible to penicillins and there have been only a few reports about penicillin-resistant E. faecalis. Three mechanisms of penicillin resistance have been reported in E. faecalis ; one is the production of beta-lactamase, another is overproduction of penicillin-binding protein (PBP) 4 or PBP5, and the third is decreasing affinities of penicillins for PBP4 by the occurrence of point mutations in the penicillin-recognition domain. In this article, we reviewed the mechanisms of resistance to penicillins in E. faecalis.