[Activity of doripenem against anaerobic bacteria].
OBJECTIVE
This study examines the activity of doripenem, a new carbapenem compound compared with amoxicillin-clavulanic acid, piperacillin+tazobactam, imipenem, clindamycin and metronidazole against 316 anaerobes.


METHODS
Inoculum preparation and agar dilution method were performed according to the CLSI method for anaerobes (M11A7).


RESULTS
At a concentration of 4μg/ml doripenem and imipenem (IMP) inhibited 122 (96 %) and 126 (99 %) strains of the Bacteroides fragilis group, respectively. In contrast, doripenem appeared more potent than IMP against Gram-positive anaerobes inhibiting at the same concentration of 4μg/ml 145/145 strains (100 %) versus 115/145 for IMP (79.3 %). Against 316 anaerobic strains, the carbapenem doripenem had an MIC(50) of 0.25μg/ml and an MIC(90) of 2μg/ml. Results were similar to those for imipenem (MIC(50) of 0.125μg/ml and MIC(90) of 4μg/ml). If we consider the resistant breakpoints of the two carbapenems as defined by EUCAST, the resistance rate for doripenem (MIC>4μg/ml) 1.6 % is similar to that of imipenem (MIC>8μg/ml) 1.3 %.


CONCLUSIONS
Thus independently of the PK/PD parameters the two carbapenems demonstrated very close activity; doripenem was more potent on Gram-positive anaerobes and slightly less potent against Gram-negative anaerobes mainly the B. fragilis group. Further clinical studies are needed to assess its usefulness in patients.
Hôpital de Tourcoing, faculté de pharmacie, université de Lille 2, BP 83 rue du Professeur-Laguesse, 59006 Lille cedex, France. luc.dubreuil@univ-lille2.fr
L
L
Dubreuil
C
C
Neut
S
S
Mahieux
C
C
Muller-Serieys
H
H
Jean-Pierre
H
H
Marchandin
C J
CJ
Soussy
A
A
Miara
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001421:Bacteria, Anaerobic / Q000187:drug effects*; D001424:Bacterial Infections / Q000382:microbiology; D001441:Bacteroides fragilis / Q000187:drug effects; D015780:Carbapenems / Q000494:pharmacology*; D000077726:Doripenem; D004352:Drug Resistance, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D006094:Gram-Positive Bacteria / Q000187:drug effects; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D008826:Microbial Sensitivity Tests
D000900:Anti-Bacterial Agents; D015780:Carbapenems; D015378:Imipenem; D000077726:Doripenem