Molecular analysis of imipenem-resistantAcinetobacter baumanniiisolated from US service members wounded in Iraq, 2003–2008

Abstract

SUMMARYGlobal dissemination of imipenem-resistant (IR) clones ofAcinetobacter baumannii–A. calcoaceticuscomplex (ABC) have been frequently reported but the molecular epidemiological features of IR-ABC in military treatment facilities (MTFs) have not been described. We characterized 46 IR-ABC strains from a dataset of 298 ABC isolates collected from US service members hospitalized in different US MTFs domestically and overseas during 2003–2008. All IR strains carried theblaOXA-51gene and 40 also carriedblaOXA-23on plasmids and/or chromosome; one carriedblaOXA-58and four contained ISAbal located upstream ofblaOXA-51. Strains tended to cluster by pulsed-field gel electrophoresis profiles in time and location. Strains from two major clusters were identified as international clone I by multilocus sequence typing.