Evaluation of dalbavancin in combination with nine antimicrobial agents to detect enhanced or antagonistic interactions

Dalbavancin is a potent, once-weekly administered lipoglycopeptide that is active against a broad spectrum of Gram-positive species. Synergy studies were performed with dalbavancin and each of nine antimicrobial agents (90 tests in total) representing nine antimicrobial classes using the broth microdilution checkerboard method to establish in vitro interactive categories. Antagonism was not observed between dalbavancin and any of the antimicrobials tested. However, dalbavancin was synergistic or partially synergistic with oxacillin for staphylococci, including methicillin-resistant strains, vancomycin-intermediate Staphylococcus aureus and enterococci, a significant finding that warrants further investigation to establish its potential clinical relevance.