IN-VITRO ACTIVITY OF BETA-LACTAMASE INHIBITORS AGAINST CLINICAL ISOLATES OF ACINETOBACTER SPECIES

Acinetobacter is an important cause of nosocomial infections, and it i s often resistant to many antibiotics. In a search for alternative age nts, three beta-lactamase inhibitors (sulbactam, clavulanate, and tazo bactam) and five beta-lactam antibiotics (imipenem, ceftazidime, ceftr iaxone, cefotaxime, and piperacillin) were tested against 68 unique cl inical isolates of Acinetobacter species. Minimum inhibitory concentra tions were determined by a broth microdilution method. Using temperatu re sensitivity testing, we identified 59 strains as Acinetobacter baum annii, one as Acinetobacter haemolyticus, and eight as indeterminate b iotype species. We demonstrated 41 of 59 (70%) strains of A. baumannii to be multiply resistant (susceptible only to amikacin and imipenem), whereas all the non-baumannii strains were not. Imipenem was the most active agent among the compounds investigated. All three beta-lactama se inhibitors had strong intrinsic activity, with sulbactam being the most active agent among the beta-lactamase inhibitors studied.