Study on oxacillinase encoding gene and homology of carbapenem-resistant Acinetobacter baumannii

Objective To analyze the drug resistance and genotypes of carbapenem-resistant Acinetobacter baumannii and their homology in Taizhou.Methods 63 Acinetobacter baumannii strains were identified and their drug susceptibility were detected by using VITEK 2 Compact.The results of drug susceptibility test were rechecked by Kribry-Bauer methods.The genes of carbapenemase were amplified by multiplex polymerase chain reaction.Homology of the resistant isolates was analyzed by PFGE.Results The 63 strains were multi-resistant.The resistant rates to common antimicrobial agents exceeded 70% except to polymyxin,amikacin,and cefoperazone/sulbactam.Among the 63 strains,60 isolates(95.2%) carried OXA-51 gene,58 isolates(92.1%) carried OXA-23 gene,and 58 strains(92.1%) possessed both the two genes.PFGE showed that Acinetobacter baumannii can be divided into 5 different genotypes,with type A and type B playing a dominant role in epidemiology.Conclusion The production of OXA carbapenemase in Acinetobacter baumannii was one of the main mechanisms of carbapenem-resistance in our hospital.OXA-23 is the major carbapenemase gene.