Prevalence of Oxacillinase and Metallo-ß-lactamases Genes in Carbapenem-Resistant Acinetobacter baumannii Isolated from Patients at Srisangworn Sukhothai Hospital during 2010-2011

Abstract

Acinetobacter baumannii is an important nosocomial pathogen with high incidence of carbapenem resistance. It affects the choice of medication in the treatment of infectious diseases. The objective of this study was to determine the prevalence of carbapenemase genes in carbapenem-resistant Acinetobacter baumannii (CRAB) isolated from patients at Srisangworn Sukhothai Hospital during November 2010 to December 2011. Total of 121 strains were screened for carbapenemase production by disk diffusion.  Then the oxacillinase (OXA) and metallo-ß-lactamases (MBLs) genes were detected using multiplex PCR. The result showed that 89 strains were resistant to meropenem (73.55%).  Three OXA genes;  bla_OXA-23-like, bla_OXA-51-like and bla_OXA-58-like, and four MBLs genes; bla_VIM, bla_SPM-1, bla_IMP and bla_SIM-1  were identified.  The bla _OXA-51-like gene was the most common OXA genes found in every strain (100%), followed by bla _OXA-23-like (19.10%) and bla_OXA-58-like (7.87%), respectively. Organisms containing both OXA and MBLs genes were found in 17strains (19.10%). In addition, 38 strains with more than one genes were found (42.70 %). The results inform the prevalence and distribution of OXA and MBLs genes in A. baumannii of Srisangworn Sukhothai Hospital as a guideline for further surveillance and prevention of drug-resistant strains.