[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.
Dubreuil
L
L
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
Neut
C
C
Mahieux
S
S
Muller-Serieys
C
C
Jean-Pierre
H
H
Marchandin
H
H
Soussy
C J
CJ
Miara
A
A
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