Multiplex PCR for genes encoding prevalent OXA carbapenemases in Acinetobacter spp.

Carbapenem resistance in Acinetobacter baumannii is a growing public health concern and is most often mediated by OXA carbapenemases. We describe a novel multiplex polymerase chain reaction (PCR) assay able to detect and distinguish alleles encoding three subgroups of acquired OXA carbapenemases (OXA-23-like, OXA-24-like and OXA-58-like) that are scattered in Acinetobacter spp., and a fourth subgroup, OXA-51-like. which appears to be intrinsic to Acinetobacter baumannii. Isolates belonging to two prevalent UK A. baumannii 'OXA' clones (OXA-23 clones 1 and 2) had alleles encoding both an intrinsic OXA-51-like and an acquired OXA-23 enzyme, whereas isolates of the 'SE clone' had only an intrinsic bla(OXA-51-like), allele. Genes encoding OXA-58 were detected (with bla(OXA-51-like)) in a cluster of related isolates from a single hospital. This simple assay will assist in monitoring the mechanisms responsible for carbapenem resistance in Acinetobacter spp. (c) 2006 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.