Genotype of OXA and Amp C Beta-lactamases in Acinetobacter baumannii in our hospital

Objective To discuss the distribution of carbapenem-resistant related genes(OXA and AmpC Beta-lactamases) and ISAba1 in Acinetobacter baumannii(AB) in our hospital,and provide a reasonable basis for the selection of antimicrobial drugs. Methods Clinical specimens were collected at the First Affiliated Hospital of Jiamusi University from September 2013 to September 2014.The VITEK-Ⅱ automated microbial identification/susceptibility testing machine was used to select 69 cases of A.baumannii and 16SrRNA was detected.Multiplex PCR detection method was used to identify Acinetobacter baumannii carrying carbapenem related resistant genes blaOXA-23,blaOXA-24,blaOXA-51,blaOXA-58,blaADC,blaDHA and ISAba1,and resistance genes of the positive amplified products were subjected to DNA sequence analysis. Results The selected 69 AB samples showed the resistant rate of SCF,IMP and MEM were 12.5%,36.7% and 38.5%， respectively.Sixty-six(95.7%) carrying blaOXA-51,32(46.4%)carrying blaOXA-23,53(76.8%)carrying blaADC and 34 (49.3%) carrying ISAba1.Out of 26 carbapenem resistant strains of Acinetobacter baumannii identified,22(84.6%) carried blaOXA-23,including 19 strains(73.1%) of the upstream detected ISAba1,24(92.3%) carried blaADC,including 10 strains of upstream ISAba1 detected. Conclusion The blaOXA-23 and blaADC may be responsible for the main reason of Acinetobacter baumannii carbapenem antimicrobial enzyme resistance.