In vitro activity of telithromycin against Gram-negative bacterial pathogens

Summary Objectives To investigate the in vitro activity of the ketolide anti-bacterial telithromycin against a range of commensal bacteria and common aerobic Gram-negative respiratory and non-respiratory pathogens. Methods Isolates were derived from both clinical material supplied by centres in various European countries and patients with community-acquired respiratory tract infections (RTIs) from centres worldwide as part of a longitudinal surveillance study. Telithromycin susceptibility testing was conducted using methods in accordance with Clinical and Laboratory Standards Institute (CLSI) guidelines and interpreted using CLSI breakpoints. Results Telithromycin displayed the highest activity against clinical isolates of Haemophilus spp., Neisseria spp., Bordetella pertussis , Legionella pneumophila and Moraxella catarrhalis , with low activity against a number of other bacterial species, including Acinetobacter spp., Enterobacteriaceae spp., Vibrio spp., Campylobacter jejuni , Aeromonas hydrophila , Plesiomonas shigelloides and Pseudomonas aeruginosa . Conclusions Telithromycin provides coverage of key Gram-negative respiratory tract pathogens, but has minimal activity against Gram-negative non-respiratory pathogens and commensal bacteria. These data support the use of telithromycin as an alternative empirical therapy for community-acquired RTIs.