IN-VITRO ACTIVITY OF 3 CARBAPENEM ANTIBIOTICS - COMPARATIVE-STUDIES WITH BIAPENEM (L-627), IMIPENEM, AND MEROPENEM AGAINST AEROBIC PATHOGENS ISOLATED WORLDWIDE

The in vitro activity of biapenem (formerly L-627 or LJC10, 627), a ne w carbapenem, was compared with that of imipenem and meropenem against >6000 clinically significant pathogens isolated in six countries worl dwide. Biapenem was active against members of the family Enterobacteri aceae with a 90% minimum inhibitory concentration (MIC(90)) ranging fr om less than or equal to 0.06 to 2 mu g/ml. Only Serratia spp. and Pro videncia spp. were less susceptible (MIC(90), 8 mu g/ml). Pseudomonas aeruginosa and Xanthomonas maltophilia displayed an MIC(90) of greater than or equal to 8 mu g/ml biapenem/ml whereas Acinetobacter spp. wer e susceptible at less than or equal to 1 mu g/ml. Oxacillin-resistant staphylococci were resistant to biapenem at >8 mu g/ml whereas oxacill in-sensitive staphylococci were susceptible at less than or equal to 1 mu g/ml. Biapenem, imipenem, and meropenem displayed poor activity ag ainst Ent. faecium (MIC(90), greater than or equal to 8 mu g/ml), and only imipenem displayed slightly better activity against Ent. faecalis (MIC(90), 4 mu g/ml). The rank order of activity against groups of is olates was Enterobacteriaceae (meropenem>biapenem greater than or equa l to imipenem), Ps. aeruginosa (biapenem=meropenem=imipenem), oxacilli n-sensitive staphylococci (imipenem greater than or equal to biapenem= merepenem), oxacillin-resistant staphylococci (biapenem=meropenem=imip enem), and Enterococcus spp. (biapenem=meropenem=imipenem). These in v itro results suggest that further developmental work on biapenem is wa rranted.