Antistaphylococcal Activities of Telavancin Tested Alone and in Combination by Time-Kill Assay

Synergy time-kill studies against 40 methicillin-resistant Staphylococcus aureus (MRSA) strains of differing resistance phenotypes were conducted. Subinhibitory concentrations of telavancin were combined with sub-MIC concentrations of other antimicrobial agents that might be used in combination with telavancin to provide Gram-negative coverage. The highest incidence of synergy was found after 24 h with gentamicin (90% of strains), followed by ceftriaxone (88%), rifampin and meropenem (each 65%), cefepime (45%), and ciprofloxacin (38%) for combinations tested at or below the intermediate breakpoint for each agent.