Evaluation of dalbavancin, tigecycline, minocycline, tetracycline, teicoplanin and vancomycin against community-associated and multidrug-resistant hospital-associated meticillin-resistant Staphylococcus aureus

Dalbavancin is an investigational semisynthetic lipoglycopeptide that is structurally related to teicoplanin. We examined the activity of dalbavancin (DAL) compared with tigecycline (TIG), minocycline (MIN), tetracycline (TET), teicoplanin (TEC) and vancomycin (VAN) against community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) and multidrug-resistant hospital-associated meticillin-resistant S. aureus (MDR HA-MRSA). Two hundred and twenty clinical isolates of CA-MRSA and MDR HA-MRSA were utilised. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined according to Clinical and Laboratory Standards Institute guidelines. Selective time–kill studies were performed against CA-MRSA and MDR HA-MRSA in triplicate. Overall, DAL exhibited low MIC values against all strains of MRSA. Time–kill studies with CA-MRSA demonstrated DAL = VAN > TIG > MIN = TEC > TET (P < 0.006), and with MDR HA-MRSA demonstrated DAL = VAN = TEC > TIG = MIN > TET (P > 0.05). DAL demonstrated potent activity against clinical strains of CA-MRSA and MDR HA-MRSA, including tetracycline-resistant S. aureus.