Genotyping of carbapenem-resistant Acinetobacter baumannii isolated from hospitalized patients in our hospital

Objective To explore the distribution of β-Lactamase gene for resistance to β-lactamase antibiotics in Acinetobacter baumannii (A. baumannii) isolated from hospitalized patients in our hospital, and provide a reasonable basis for the clinical selection of antimicrobial drugs. Methods Total 110 strains of A. baumannii collected at the First Affiliated Hospital of Jiamusi University from September 2013 to June 2015 were tested for the bacteria identification and drug susceptibility by using the VITEK-II and Walkway-40 VITEK 2 COMPACT automatic microbiology analyzer. 16S rRNA gene sequencing and multiplex PCR for identification of Ambler class A beta-lactamases were performed. Results The resistant rate of 110 A. baumannii samples to SCF, MEM and IMP were 13.3%, 38.5% and 49.3%, respectively. The Ambler class D beta-lactamases gene were as follows:96 strains of OXA-53, OXA-23 strains (48.18%), 29 strains OXA-24 (26.36%), 6 strains of OXA-58 (5.45%), mainly OXA-51 and OXA-23; metal enzyme B included 1 strain of IMP (0.90%) and 6 strains of SIM (5.45%), 84 strains of ADC (76.36%), 66 strains of TEM (60.00%), 16 strains of GES (14.54%), 8 strains of PER (7.27%), 7 strains of SHV (6.36%), and 5 strains of VEB (4.54%).Among 50 strains of carbapenem-resistant A. baumannii, the detection rate of OXA-23, OXA-51, OXA-24, ADC and TEM were 84.00%, 92.00%, 26.00%, 92.00% and 88.00%, respectively. When compared with carbapenem-sensitive A. baumannii, there was significant difference in the positive of CSAB OXA-23, ADC and TEM gene. Conclusion OXA, Amp C and extended spectrum β-Lactamase may be responsible for the resistance to β-lactamase antibiotics in A. baumannii in our hospital.