Comparative in vitro activity of PH-027 versus linezolid and other anti-anaerobic antimicrobials against clinical isolates of Clostridium difficile and other anaerobic bacteria.

Abstract PH-027 is a new 5-triazole oxazolidinone synthesized in our laboratories, which shows strong activity against Gram-positive aerobic bacteria including clinical isolates. The objective of this study was to investigate the In Vitro activity of this compound in comparison with linezolid and other antibiotics against Gram-positive and Gram-negative anaerobes. The In Vitro activity of PH-027 in comparison with those of linezolid and other antimicrobial agents was evaluated against 201 clinical isolates of Gram-positive and Gram-negative anaerobic bacteria by agar dilution and Etest methods.PH-027 showed excellent activity, with minimum inhibitory concentrations (MIC) in the range of 0.12-4.0 μg/ml against all isolates; MIC90s being 4.0, 1.0, 2.0, 2.0 and 2.0 μg/ml against Clostridium difficile, Peptostreptococcus spp., Bacteroides fragilis, Prevotella bivia and Fusobacterium spp. respectively. In comparison, linezolid had MIC in the range of 0.5-4.0 μg/ml against all isolates, with MIC90s of 2.0, 4.0,...