blaOXA and blaNDM mediated carbapenemase resistance in Acinetobacter baumannii species

Abstract

The growing rise of the occurrence of Carbapenem-Resistant Acinetobacter baumannii (CRAB) in critical care units is a disaster of the existing antimicrobial protocols, with the main cause of this problem being the dissemination of oxacillinase (OXA) and metallo-beta-lactamase (MBL) genes. In the present study, a cross-sectional molecular analysis of 215 clinical isolates was used to assess the antimicrobial susceptibility and define the genotypic presence of blaOXA-23, blaOXA-51 and blaNDM-1 by using multiplex PCR assays in a tertiary care center. The resistance to meropenem was found to be 92.5% phenotypically and intrinsic blaOXA-51 was identified in 100% of isolates with acquired blaOXA-23 (78.6) and blaNDM-1 (34.4) in 22.3%. Thus, data shows the rise of A. baumannii strains that are co-producing OXA and NDM enzymes is an indication of the transition to pan-drug resistance. Hence, combined molecular surveillance and stewardship measures are in urgent need.