Prosthetic Valve Endocarditis Due to Small-Colony Staphylococcal Variants

Abstract

Although Staphylococcus epidermidis is a major cause of prosthetic valve endocarditis, little is known about the pathogenesis of this disease. In one case described herein, small colony variant forms of S. epidermidis were isolated from clinical specimens obtained from a patient with prosthetic valve endocarditis. Data from the rat model of experimental endocarditis provide further evidence that small-colony variants maybe operative in the production of prosthetic valve infection. Moreover, a review of the literature indicates that small-colony variants could account for the subtle clinical course after prolonged dormant infection that characterizes S. epidermidis prosthetic valve endocarditis. It is therefore hypothesized that small-colony variants of S. epidermidis may play a role in the pathogenesis of prosthetic valve endocarditis.