Molecular epidemiological analysis of carbapenem-resistant Klebsiella pneumonia in China from 2009 to 2016

Abstract

Objective The study aimed to investigate the drug sensitivity and molecular epidemiological analysis of carbapenem-resistant Klebsiella pneumoniae in China from 2009 to 2016. Methods For Klebsiella pneumoniae collected from China Antimicrobial Resistance Surveillance Trial (CARST) from 2009 to 2016, those resist to ertapenem were screened out as the carbapenem-resistant Klebsiella pneumoniae(CRKP). Antibiotic susceptibilities of 14 antibacterial agents to the bacteria were assessed by minimum inhibitory concentration (MIC) using two-fold agar dilution test which was recommended by the Clinical and Laboratory Standard Institute (CLSI). Carbapenemases were filtered out by the modified carbapenem inactivation method(mCIM) and EDTA-modified carbapenem inactivation method(eCIM) test, PCR was used to screen for the presence of carbapenemase genes or not. Pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) were used to analyze the homology of these isolates. Results A total of 193 CRKP were screened out in the 2 502 Klebsiella pneumoniae isolates. The resistance rates of 193 CRKP isolates to colistinE (4.0%), tigecycline (7.2%), fosfomycin (25.4%) and amikacin (38.3%) were less than 40%. However, the resistance rates to the other 9 antimicrobial agents were higher than 65%. There were 143 carbapenemase gene detected in 193 CRKP, of which blaKPC-288(45.6%) and blaNDM-140(20.7%) were the most common. In the 126 isolates of Klebsiella pneumoniae producing KPC-2 and NDM-1 carbapenemases, a total of 33 ST-types were detected, mainly was ST11 (59.5%). All ST11 strains produce KPC-2 carbapenemase. A total of 111 clones were obtained from PFGE fingerprints, there were 12 clones in which the same clone strains were equal or greater than 2. Conclusion The resistance rate of Klebsiella pneumoniae to carbapenems has been rising from 2009 to 2016, and clinicians should take reasonable measures to strengthen the monitoring of resistance to CRKP and control its spread across the country. Key words: Klebsiella pneumoniae; Carbapenems; Drug resistance, bacterial; Microbial sensitivity tests; Electrophoresis, gel, pulsed-field; Multilocus sequence typing