Telavancin activity in vitro tested against a worldwide collection of Gram-positive clinical isolates (2014).

Abstract

Telavancin activity was measured against Gram-positive pathogens collected worldwide during 2014 using the revised broth microdilution testing method. The results were compared with previous reports. A total of 10552 isolates from 86 sites located in 32 countries were included as part of the Telavancin International Surveillance Program for the Americas, Europe and Asia-Pacific. Telavancin had MIC50 and MIC90 values of 0.03μg/mL and 0.06μg/mL, respectively, against Staphylococcus aureus, regardless of methicillin susceptibility, and inhibited all S. aureus isolates at the CLSI breakpoint (≤0.12μg/mL). Telavancin was eight-fold more active than daptomycin (MIC50/90, 0.25/0.5μg/mL) and 16-32-fold more active than vancomycin (MIC50/90, 1/1μg/mL) and linezolid (MIC50/90, 1/1μg/mL) against methicillin-resistant S. aureus (MRSA). Telavancin was also active against coagulase-negative staphylococci isolates (MIC50/90, 0.06/0.06μg/mL). Vancomycin-susceptible Enterococcus faecalis isolates (n=718) were all inhibited by telavancin (MIC50/90, 0.12/0.12μg/mL) at ≤0.25μg/mL (CLSI breakpoint), except for a single isolate (MIC, 0.5μg/mL). All Enterococcus faecium and E. faecalis isolates with telavancin MICs of ≥0.5μg/mL and ≥1μg/mL, respectively, had a VanA phenotype. Based on the MIC90 values, telavancin was at least eight-fold more potent than comparators against vancomycin-susceptible enterococci. With the exception of Streptococcus agalactiae (MIC50, 0.03μg/mL), all tested species of streptococci exhibited telavancin MIC50 values of ≤0.015μg/mL. These in vitro results from 2014 highlight the potent in vitro activity of telavancin and demonstrate that its activity was virtually unchanged compared with the corresponding 2013 telavancin surveillance results.