Drug-resistant gene of blaOXA-23, blaOXA-24, blaOXA-51 and blaOXA-58 in Acinetobacter baumannii

We distinguished the four alleles of OXA subgroups from 339 strains of Acinetobacter baumannii using Polymerase Chain Reaction, and investigated distributions of OXA subgroups in clinical isolated strains. A total of 196 Acinetobacter baumannii were isolated from the Central Hospital of Zhumadian between 2010 and 2014. Amplification of OXA genes, blaOXA-23, blaOXA-24, blaOXA-51 and blaOXA-58, were performed by PCR. Patients with Acinetobacter baumannii were selected from ICU, pneumology, emergency and cerebral surgery, accounting for 33.67%, 17.86%, 16.33% and 32.14%, respectively. Most strains showed resistance to different classes of agents, especially in ceftazidime, piperacillin, cefepime, nitrofurantoin and ertapenem. Multiplex PCR results showed, out of the 339 isolated strains, 164 (48.38%) were blaOXA-51, 157 (46.31%) were blaOXA-23, 18 (5.31%) were blaOXA-58, and no strain for blaOXA-24. 143 (47.67%) strains of blaOXA-51, 143 (47.67%) strains of blaOXA-23, and 14 (4.66%) strains of blaOXA-58 showed multidrug-resistant. In conclusion, our study found that OXA-51 and OXA-23 were the main mechanisms of resistant or sensitivity to carbapenems.