Outbreak of Carbapenem-Resistant Acinetobacter baumannii Producing the Carbapenemase OXA-58 in Turkey

摘要

The use of carbapenems to eradicate multi-drug resistant (MDR) Acinetobacter baumannii may become compromised by the spread of carbapenem-hydrolyzing class D β-lactamase (CHDL) genes (OXA-23, OXA-40, or OXA-58). Here, we describe the phenotypical and genotypical characterization of MDR A. baumannii isolates, recovered between June and November 2003 in a tertiary-care hospital in Antalya, Turkey.Hundred and sixteen MDR A. baumannii isolates were isolated from 23 patients, mostly from respiratory samples and from 11 environmental samples. These MDR isolates, belonged to a single clone and remained susceptible to colistin and rifampin only. They produced CHDL OXA-58. In addition, they were also positive for the blaOXA-51, for a novel blaAMPC(ADC-43) gene and for ISAba1. The blaOXA-58 gene was located onto a non self-transferable 50-kb plasmid that could be electroporated to A. baumannii 7010 reference strain. One isogenic carbapenem-susceptible strain lost its plasmid carrying blaOXA-58 gene. PCR mapping identified similar genetic structures surrounding the blaOXA-58 gene as for the prototype blaOXA-58 gene, e.g. two ISAba3-like insertion sequences bracketing blaOXA-58 gene. This is the first molecular description of an outbreak of OXA-58- producing A. baumannii isolates in Turkey, further underlining the global spread of such carbapenemase- producing strains in the Mediterranean area.