Comparative in vitro antibacterial activity of the new carbapenem meropenem (SM-7338)

The in vitro antimicrobial activity of the new carbapenem meropenem (SM-7338) was determined by an agar dilution method in comparison with imipenem, ticarcillin/calvulanic acid, ceftazidime and the fourth-generation cephalosporin cefepime (BMY 28142). Meropenem showed superior activity against Enterobacteriaceae (MIC90 less than or equal to 0.06 mg/l) and against non-fermentative gram-negative rods, with the exception of Xanthomonas maltophilia. Meropenem had excellent activity against beta-lactamase-producing Haemophilus influenzae and Neisseria gonorrhoeae, and against the Bacteroides fragilis group. Imipenem was slightly more active then meropenem against gram-positive cocci especially Enterococcus faecalis.