POLYCLONAL STAPHYLOCOCCUS ENDOCARDITIS

Coagulase-negative staphylococcus (CNS) is the most frequent cause of nosocomial bacteremia and prosthetic valve endocarditis. CNS bacteremi a can be polyclonal. No data exist on the clonality of CNS causing end ocarditis. We present a case of CNS aortic homograft endocarditis in w hich at least five different genotypes of CNS were identified in initi al blood-culture isolates by genomic macrorestriction enzyme analysis and pulsed field gel electrophoresis. Since the polyclonality was acco mpanied by differences in antibiotic susceptibility, this observation may have important consequences for the treatment of CNS endocarditis. Because of the parallels in the pathogenesis of CNS prosthetic valve endocarditis and CNS infections of a variety of other prosthetic devic es, it might also have consequences for CNS prosthetic device infectio ns in general. We suggest that antibiotic susceptibility testing of ju st one blood-culture isolate may be insufficient.