Abstract:Objective To investigate the molecular epidemiological characteristics of multidrug-resistant Acinetobacter baumannii (MDRAB) in a tertiary hospital over a four-year period. Methods Fifty-one MDRAB strains isolated from 2013 to 2016 were collected. Carbapenemase genes were analyzed by PCR, and the genetic relationship between isolates was identified by multilocus sequence typing (MLST). Results Carbapenemase gene MDRA blaBOXA-51 was detected in all 51 isolates, and gene blaOXA-23 demonstrated positive rates of 94.12%. There were three reported STs in the MLST analysis, followed by ST191 (52.94%), ST208 (31.37%), and ST136 (15.69%), all of which belonged to clone complex CC92. Among them, ST208 spread continuously throughout the hospital in the four years, ST191 and ST136 spread intermittently at different periods. Conclusion The outbreak of the same strain ST occurred in all the MDRABs isolated in this hospital, which warned the hospital should strengthen its prevention of nosocomial infections.