Abstract:Objective To evaluate the carrying status and homology of drug resistance genes of carbapenem-resis-tant Acinetobacter baumannii (CRAB) in a tertiary first-class hospital. Methods 40 strains of CRAB were collected from this hospital between October 2017 and October 2018, carrying status of drug resistance genes was detected by polymerase chain reaction (PCR), homology was analyzed by pulsed-field gel electrophoresis (PFGE). Results The resistance rate of 40 strains of CRAB to most antimicrobial agents was about 90%, resistance rate to tigecycline was relatively low (2.9%, intermediate resistance was not included). Detection rate of drug resistance gene ADC was 100%, detection rates of OXA-51 and qacE△1-sull were 90%(n=36 strains) and 80.0%(n=32 strains) respectively, KPC gene was not found. Each CRAB strain was detected 2-8 kinds of resistance genes, and 37.5% of strains (n=15 strains) were detected 6 kinds of resistance genes; among the detected drug resistance gene combinations, 29 strains (72.5%) were simultaneously detected ADC+OXA-23+OXA-51 genes, 26 strains (65.0%) were detected ADC+intl1+qacE△1-sull genes, 19 strains(47.5%) were detected ADC+qacE△1-sull+ant(3″) -Ⅰ genes, 11 strains(27.5%) were detected ADC+ant(3″) -Ⅰ+aac(3) -Ⅰ genes. 19 different types were divided by PFGE homology detection, each type contained 1-9 strains, including 9 strains of type A5 and 8 strains of type A18, mainly from intensive care unit. Conclusion CRAB is highly resistant to common clinical antimicrobial agents, OXA-23 and OXA-51 are most likely to be the main causes of the resistance of AB in this hospital, homology analysis revealed the presence of CRAB HAI in different wards in this hospital.