Abstract: Objective To investigate the drug resistance variation and molecular epidemiology of Acinetobacter baumannii isolated from patients in neurosurgery department at Renji Hospitaland analyze the homology, in order to provide the reference for clinical treatment and nosocomial infection control. Methods A total of 87 clinical isolates of Acinetobacter baumannii were collected from July 2011 to June 3013 in neurosurgery department of Renji Hospital. The minimal inhibitory concentrations (MIC) of 12 antimicrobial agents against 87 Acinetobacter baumannii isolates were determined by agar dilution method. The genotype was identified by multilocus sequence typing technique, and the epidemiology characteristic was analyzed further. Results The 87 Acinetobacter baumannii isolates were commonly resistant to cephalosporin, fluoroquinolone, aminoglycoside and carbopenem, and the drug resistance rates increased year by year. A total of 6 genotypes were identified among 87 Acinetobacter baumannii isolates:ST-208(45 isolates), ST-191(15 isolates), ST-540(8 isolates), ST-195(2 isolates), ST-381(2 isolates) and ST-368(1 isolate). ST-208 was the main epidemiology type. The ST types had the homologous relevance belonging to CC92 except for ST-381. Conclusions The drug resistance rate of Acinetobacter baumannii to antimicrobial agents increases year by year, and there is dissemination characteristic, which should be paid more attention. Infection monitoring should be enhanced to reduce the spread of drug-resistant bacteria.

Key words: Acinetobacter baumannii, Minimal inhibitory concentration, Multilocus sequence typing