Abstract: Objective To investigate the clinical distribution and drug resistance of the five clinically important bacteria isolates in the hospitals from 2012 to 2016 in order to provide reference for the proper use of antibiotics. Methods Tests of bacterial identification and antibiotic susceptibility were performed with the MicroScan WalkAway 96 PLUS bacterial identification system. All of the data were analyzed by WHONET5.6 software. Results An average of 1 520 isolates were harvested each year. Among them Escherichia coli and Klebsiella pneumonia producing extended-spectrum β-lactamase （ESBL） strains showed a downward trend. The resistance rate of E. coli to carbapenem-based antibiotics was basically stable during the five years studied, and that of K. pneumoniae to carbapenems showed an upward trend. Pseudomonas aeruginosa presented decreased resistance to all of the monitored antimicrobials, including imipenem and meropenem. Carbapenem resistance rate of Acinetobacter baumannii gradually increased from 32.8% to 82.3%. The positive rate of methicillin-resistant Staphylococcus aureus dropped from 45.2% in 2012 to 37.5% in 2016. Conclusion The prevalence of carbapenem-resistant K. pneumoniae and A. baumannii is increasing and of great concern in recent years.

Key words: Drug resistance, Extended-spectrum beta-lactamase, Carbapenem