Carbapenem-resistant and OXA-23-producing Acinetobacter baumannii isolates in the United Arab Emirates

ABSTRACTFive carbapenem-resistant Acinetobacter baumannii isolates, collected from the United Arab Emirates in 2006, were investigated to identify the mechanism(s) responsible for carbapenem resistance. Genotyping was performed by pulsed-field gel electrophoresis, and the location of the blaOXA-23 gene was determined by using the endonuclease I CeuI technique and mating-out assays. The four isolates in which the blaOXA-23 gene was located on the chromosome within a Tn2006 composite transposon were clonally related. The single nonclonally related isolate harboured the blaOXA-23 gene on a 70-kb transferable plasmid. This study provides the first description of the dissemination of carbapenem-resistant A. baumannii isolates carrying Tn2006 on their chromosome. It is also the first report of OXA-23-producing A. baumannii isolates in the Middle East.