IN-VITRO ACTIVITY OF MEROPENEM COMPARED WITH IMIPENEM, METRONIDAZOLE,AMPICILLIN, AND AMPICILLIN SULBACTAM AGAINST ANAEROBES/

The aim of the present study was to compare the in vitro activity of m eropenem (ICI 194660, CAS 96036-03-2) with imipenem, metronidazole, cl indamycin, ampicillin and ampicillin/sulbactam against a variety of an aerobic bacteria using an agar dilution method. 423 clinical isolates were tested belonging to 70 species of 15 anaerobic genera. They inclu ded Bacteroides fragilis (n = 62), Bacteroides thetaiotaomicron (n = 4 5), Prevotella bivia (n = 11), Fusobacterium nucleatum (n = 12), Clost ridium perfringens (n = 15) and several rarely isolated species and ge nera, e.g. Selenomonas sputigena and Clostridium symbiosum. Bacteroide s species were inhibited by meropenem at less than or equal to 2.0 mu g/ml, Clostridium species, including C. difficile, at less than or equ al to 4.0 mu g/ml and all the other anaerobes at less than or equal to 0.5 mu g/ml. Meropenem and imipenem were the most active substances b ut often equal to, or only slightly better than, metronidazole, clinda mycin or ampicillin/sulbactam, dependent on species. Meropenem was esp ecially active against Bacteroides gracilis (MIC(90) 0.015 mu g/ml), P revotella disiens (MIC(90) 0.03 mu g/ml), Fusobacterium nucleatum (MIC (90) 0.015 mu g/ml), Clostridium perfringens (MIC(90) 0.015 mu g/ml) a nd Veillonella parvula (MIC(90) 0.03 mu g/ml). The results obtained in dicate that meropenem might be a useful adjunct to chemotherapy of ana erobic and mixed aerobic and anaerobic infections.