Distribution, molecular epidemiology and resistance genes of carbapenem resistant Klebsiella pneumoniae in Zhejiang Province

Objective To retrospectively investigate the distribution, molecular epidemiology and carbapenemases-encoding genes of carbapenem resistant Klebsiella pneumoniae (CRKP) in Zhejiang Province. Methods A total of 772 clinical isolates of K. pneumoniae isolated from 9 hospitals in Zhejiang Province in 2011 were selected, and antimicrobial susceptibility testings were carried out with disk diffusion or broth microdilution method. Polymerase chain reaction (PCR) was used to detect resistant genes, and molecular typing was performed by multilocus sequence typing (MLST) and pulsed field gel electrophoresis (PFGE). Results A total of 48 CRKP (6.2%) were screened in 9 hospitals. Carbapenemase-encoding genes were detected in 39 isolates by PCR, among which 37 (77.1%) were identified as blaKPC-2 and 2 were blaIMP-4. MLST showed that ST11 was the dominant ST type (30, 62.5%). Results of PFGE showed that 48 CRKP can be divided into 15 types. CRKP was found in 6 hospitals except hospitals in Wenzhou, Jiaxing and Shaoxing. Conclusions In 2011, CRKP is distributed in most areas of Zhejiang Province. The production of KPC-2 is the most important carbapenem resistance mechanism and ST11 is the most prevalent ST type. Key words: Klebsiella pneumoniae; Epidemiology, molecular; Drug resistance; Carbapenems; Distribution