Investigation on the genomic diversity of OXA from isolated Acinetobacter baumannii.

We distinguished the four alleles of OXA subgroups from 138 strains of Acinetobacter baumannii using Polymerase Chain Reaction, and investigated distributions of OXA subgroups in clinical isolated strains. A total of 170 Acinetobacter baumannii were isolated from Shenzhen Longgang Central Hospital between 2010 and 2013. Amplification of OXA genes, blaOXA-23, blaOXA-24, blaOXA-51 and blaOXA-58, were performed by multiplex PCR. Multiplex PCR results showed, out of the 96 strains of Acinetobacter baumannii, 50 (52.08%) strains were positive for only blaOXA51 gene, and 46 (47.92%) showed positive for both blaOXA51 and blaOXA58 genes. Among 96 strains of Acinetobacter baumannii, 48 strains were resistant to carbapenems, and 48 strains were sensitivity to carbapenems. blaOXA51 and blaOXA58 showed resistant or sensitivity to carbapenems. In conclusion, we found that blaOXA-51 and blaOXA-5 were the main mechanisms of resistant or sensitivity to carbapenems.