Staphylococcus epidermidis is the most important member of the coagulase-negative staphylococci and one of the most abundant colonizers of human skin.S.epidermidis is a bacterial species that is commonly described as relatively innoc-uous,which is in part due to the notion that it lacks secreted toxins with limited capability of infection.S.epidermidis pro-duces a series of molecules that provide protection from host defenses,including many proteins and exopolymers.Further-more,recent research has identified a family of cytolytic peptidesin S.epidermidis,the phenolsoluble modulins (PSMs),and the notion that S.epidermidis is virtually toxin-free had to be somewhat revised.