In vitro activity of oritavancin against community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), vancomycin-intermediate S. aureus (VISA), vancomycin-resistant S. aureus (VRSA) and daptomycin-non-susceptible S. aureus (DNSSA).

Isolates of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA), vancomycin-intermediate S. aureus (VISA), vancomycin-resistant S. aureus (VRSA) and daptomycin non-susceptible S. aureus (DNSSA) are increasing in frequency and new antistaphylococcal therapies are needed. Microdilution testing using Mueller-Hinton broth was used to determine the minimal inhibitory concentrations (MICs) of oritavancin and nine additional antimicrobial agents against 92 CA-MRSA, 23 VISA, 7 DNSSA and 10 VRSA isolates. Minimal bactericidal concentrations were also determined. Pulsed-field gel electrophoresis (PFGE) was performed. Staphylococcal cassette chromosome mec (SCCmec) typing as well as assays for Panton-Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME) genes were performed. Oritavancin was more bactericidal than any of the other comparators against CA-MRSA and demonstrated excellent activity against VRSA and VISA.