First report of the blaOXA-23 gene in a clinical isolates of Acinetobacter baumannii in Najaf hospitals-Iraq

Abstract

Carbapenemase producing Acinetobacter baumannii is frequently associated with nosocomial infections. Increasing resistance to carbapenems, may significantly reduce the choice of effective antibiotics. This study was conducted to determine the occurrence of carbapenemase producing A. baumannii isolates obtained from Najaf hospitals. Isolates were identified according to API 20NE system and more confirmed using 16Sr RNA gene. Carbapenem susceptibility was assayed by microbroth dilution and other antibiotics using disks diffusion test. Phenotypic detection of carbapenemase was performed using the imipenem-EDTA disk and modified Hodg tests. Then isolates were subjected to monoplex PCR targeting blaOXA-23, blaIMP and blaVIM genes. Twelve (1.5.%) A. baumannii isolates were recovered from clinical infections. Five (41.6%) of isolates were found to be imipenem and meropenem resistant (MIC ranged 128-256 μg mL-1), of which, 4 (66.6%) gave positive result with the imipenem-EDTA disk and modified Hodg test. PCR experiments showed only two (33.3%) isolates were harbored blaOXA-23 gene. The present findings suggest that emergence of OXA-23 carbapenemase-producing A. baumannii clinical isolates in Najaf hospitals.