Resistance to Daptomycin in the Treatment of Methicillin Resistant Staphylococcus aureus Bacteremia

Abstract

Staphylococcus aureus is an aerobic gram positive bacterium that can cause harmful skin infections and bacteremia. Some strains of S. aureus have become resistant to synthetic penicillin (Methicillin) and therefore need to be treated with Daptomycin, a novel lipopeptide antibiotic that was approved by the Food and Drug Administration (FDA) for treatment of gram positive skin infections in 2003. Two patients at St. John Hospital & Medical Center (Detroit, MI) were on prolonged treatment of Daptomycin for S. aureus bacteremia and blood cultures showed non-susceptibility to the drug. Both patients’ blood cultures were shown to develop non-susceptibility to Daptomycin after 5 and 7 days of treatment.