Emergence of a Clinical Daptomycin-Resistant <i>Staphylococcus aureus</i> Isolate during Treatment of Methicillin-Resistant <i>Staphylococcus aureus</i> Bacteremia and Osteomyelitis

Abstract

The emergence of a clinically daptomycin-resistant Staphylococcus aureus isolate occurred during treatment of methicillin-resistant S. aureus bacteremia and probable vertebral osteomyelitis. The breakthrough isolate was indistinguishable from pretreatment daptomycin-susceptible isolates by pulsed-field gel electrophoresis. Daptomycin nonsusceptibility was confirmed by MIC and time-kill curve analyses.