Characterization of genetic diversity of carbapenem-resistant Acinetobacter baumannii clinical strains collected from 2004 to 2007

Genotypes of carbapenem-resistant Acinetobacter baumannii collected by the clinical microbiology laboratory of a university hospital in Chicago, IL, between 2004 and 2007 were analyzed by pulsed-field gel electrophoresis. A single genotype established predominance after being introduced in 2005. Analysis of carbapenemases by PCR revealed that imipenem resistance but not meropenem resistance was associated with the presence of bla(OXA-23) and bla(OXA-40) genes.