Dalbavancin has potent in vitro activity against staphylococci and streptococci, including isolates with multi-drug-resistant (MDR) phenotypes, according to a study reported here at the 25th European Congress of Clinical Microbiology and Infectious Diseases (ECCMID).
For the study, Dr Rodrigo E Mendes, JMI Laboratories, North Liberty, Iowa, and colleagues collected Gram-positive isolates from 57 sites in Europe, Russia, Turkey, and Israel as part of the SENTRY Antimicrobial Surveillance Program. A total of 9,304 Staphylococcus aureus were analysed and 26.6% were methicillin-resistant and 42.6% were resistant to at least 3 additional drug classes.
Dalbavancin had similar modal MIC, MIC50 and MIC90 values (all 0.06 mg/L) when tested against MRSA isolates, regardless of their MDR phenotype. In addition, dalbavancin inhibited 99.5% to 99.9% of these isolates at the US Food and Drug Administration (FDA) breakpoint for susceptibility (≤0.12 mg/L). Overall, viridans group streptococci (VGS) and beta-haemolytic streptococci (BHS) were very susceptible to dalbavancin, regardless of resistance phenotype.
“Comparator agents with similar indications, such as vancomycin, teicoplanin, daptomycin, and linezolid also demonstrated in vitro coverage against multi-drug-resistant strains,” the authors wrote in their poster presentation. “However, dalbavancin had the greatest potency overall against these isolates.”