Dalbavancin compared with vancomycin for prevention of Staphylococcus aureus colonization of devices in vivo☆

Although active against free-floating bacteria, vancomycin displays a poor activity against organisms embedded within the biofilm surrounding implanted devices. Dalbavancin is a novel glycopeptide antibiotic with strong activity against staphylococci and a long half-life that allows for once-a-week dosing. The objective of this animal study was to examine the ability of dalbavancin and vancomycin to prevent Staphylococcus aureus colonization of devices.Twelve rabbits were randomized, in three groups of four each, to receive intravenous injections of dalbavancin, vancomycin or normal saline (control). Eight polyurethane catheter segments were subcutaneously implanted in the back of each rabbit, then inoculated with S. aureus. Rabbits were sacrificed a week later and explanted devices were cultured.The rates of device colonization were comparable in the vancomycin (53%) and control (47%) groups, whereas only 28% of devices in the dalbavancin group became colonized. There was a trend (although not statistically significant) toward a lower rate of device colonization following receipt of dalbavancin vs. vancomycin (P = 0.07) or saline (P = 0.02).The demonstrated efficacy of dalbavancin in this animal study suggest that this novel antibiotic may have an important role in the prevention and treatment of device-related infection.