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 β-haemolytic and viridans group streptococci. Telavancin also had excellent activity against vancomycin-susceptible enterococci (MIC90 0.5 mg/L), and although its MICs were elevated against VanA strains (Enterococcus faecalis MIC90 8 mg/L and Enterococcus faecium MIC90 4 mg/L), its MIC90 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.