IN-VITRO ACTIVITY OF HMR-3647 AGAINST ANAEROBIC-BACTERIA

The aim of the present investigation was to determine the in vitro act ivity of HMR 3647 compared with other antimicrobial agents against ana erobic bacteria. The activity of HMR 3647 was determined against 342 c linical isolates of anaerobic bacteria by the agar dilution method and was compared with azithromycin, clarithromycin, roxithromycin, erythr omycin, cefoxitin, imipenem, clindamycin and metronidazole. Among the macrolides HMR 3647 and among the beta-lactams imipenem were the most active agents tested. Anaerobic cocci (50 strains) had the following m inimum inhibitory concentrations (MICs): HMR 3647, range 0.016-0.125 m g/l; imipenem, range 0.016-0.064 mg/l. Propionibacterium acnes (30 str ains): HMR 3647, 0.016-1.0 mg/l; imipenem, 0.032-0.064 mg/l. Clostridi um perfringens (30 strains): HMR 3647, 0.125 mg/l; imipenem, 0.016-0.5 mg/l. Clostridium difficile (50 strains): HMR 3647, 0.125-256 mg/l; i mipenem, 4.0-8.0 mg/l. Bacteroides fragilis (102 strains): HMR 3647, 0 .032-16 mg/l; imipenem, 0.064-0.25 mg/l. Bacteroides and Prevotella sp ecies (50 strains): HMR 3647, 0.016-4.0 mg/l; imipenem, 0.016-0.25 mg/ l. Fusobacterium nucleatum (30 strains): HMR 3647, 0.016-8.0 mg/l; imi penem, 0.008-0.064 mg/l. HMR 3647 may be useful as treatment and proph ylaxis for infections due to anaerobic bacteria.