In vitro activity of telavancin against recent Gram-positive clinical isolates:: results of the 2004-05 Prospective European Surveillance Initiative

Objectives: Telavancin is a novel semi-synthetic lipoglycopeptide currently in late-stage clinical development for the treatment of serious infections due to Gram-positive bacteria. The objective of this study was to provide a baseline prospective assessment of its in vitro activity against a large and diverse collection of Gram-positive clinical isolates from Europe and Israel. Methods: Gram-positive clinical isolates, collected between October 2004 and December 2005 from 36 hospital laboratories in 15 countries, were tested by broth microdilution using CLSI methodology. Results: In total, 3206 isolates were collected. Telavancin had potent activity against Staphylococcus aureus and coagulase-negative staphylococci (MIC range <= 0.015 to 2 mg/L), independent of resistance to methicillin or to multiple drugs. Telavancin had particularly strong activity against streptococcal isolates (MIC range <= 0.001 to 0.5 mg/L), including penicillin-resistant and multiple drug-resistant Streptococcus pneumoniae and erythromycin non-susceptible beta-haemolytic and viridans group streptococci. Telavancin also had excellent activity against vancomycin-susceptible enterococci (MIC(90) 0.5 mg/L), and although its MICs were elevated against VanA strains (Enterococcus faecalis MIC(90) 8 mg/L and Enterococcus faecium MIC(90) 4 mg/L), its MIC(90) was substantially lower than observed with available glycopeptides. Conclusions: Telavancin has potent in vitro activity against contemporary Gram-positive clinical isolates from diverse geographic areas in Europe and Israel.