In vitro anti-anaerobic activity of the cephalosporin derivative RWJ 54428, compared to seven other compounds

Abstract

Agar dilution MIC was used to test the activity of RWJ 54428, a new cephalosporin derivative, compared to imipenem, meropenem, ceftriaxone, piperacillin, piperacillin-tazobactam, clindamycin and metronidazole against 363 anaerobes isolated from clinical specimens. RWJ 54428 had low MICs against most β-lactamase-negative Gram-negative rods, and all Gram-positive strains except Clostridium difficile. Imipenem and meropenem had the lowest MICs (MIC50s of 0.125mg/L and MIC90s of 1.0mg/L). Piperacillin-tazobactam, clindamycin and metronidazole were active against most strains, and ceftriaxone was active mainly against β-lactamase-negative organisms.