Detection and analysis of OXA-23 carbapenemase gene in Acinetobacter baumannii isolates resistant to imipenem

Objective To investigate the exsistence status of oxa-23 carbapenemase gene in Acinetobacter baumannii isolates resistant to imipenem,and to explore the drug-resistant mechanism.Methods 16 strains of nonduplicate clinical strains were isolated from Apr.2012 to Sept.2012,and K-B disk diffuse method was used insusceptibility testing.Regular polymerase chain reaction(PCR) was performed on the clinical isolates using primers specific for D-type carbapenemase OXA-23 gene,then the PCR product was sequened and we compared the sequences with the gene bank.Results There are 11 strains of Acinetobacter baumannii(68.8%) carrying with OXA-23gene.Two strains with OXA-23 positive gene are randomly chosen for test and they are in 100% homogenous to OXA-23 standard strain.Conlusions The isolation strains mainly comes from sputum specimens,and the strains of imipenem-resistance Acinetobacter baumannii carry a relatively higher rate of OXA-23 gene.We consider the resistance of the isolates may be associated with OXA-23 carbapenemases gene.