Multilocus sequence typing of carbapenem-resistant Klebsiella pneumoniae isolates and its utility in profiling clinical infections / 中国感染与化疗杂志

ABSTRACT

Objective To investigate the homology of carbapenem-resistant Klebsiella pneumoniae (CR-KPN) isolates by multilocus sequence typing (MLST) method,and profile CR-KPN infections in terms of MLST sequence types (STs).Methods A total of 61 CR-KPN isolates were collected in five hospitals from Liaoning Province from January 2013 to June 2015.The MICs of 14 antimicrobial agents against these isolates were determined by broth microdilution method.The genotypes of carbapenemases were analyzed by PCR and DNA sequencing techniques.The homology of CR-KPN isolates were analyzed by MLST method.The clinical data of patients with CR-KPN infection were reviewed to characterize CR-KPN infections.Results A total of 18 STs were identified among the 61 CR-KPN strains according to MLST data.More than 50 ％ of the isolates belonged to ST11 (53.3 ％).ST11 strains showed higher resistance rate to carbapenems and higher prevalence of KPC-2 type carbapenemase.Univariate analysis indicated that more ST 11-infected patients were treated in ICU and with mechanical ventilation than non-ST11 CR-KPN-infected patients (P＜0.05).ST2033,ST2135,ST2193,ST2194,ST2195 and ST2196 were the STs firstly registered in the world.The eBURST analysis showed that ST2193,ST2194,ST2195 and ST 11 were closely related.Clinical data indicated that the prevalent CR-KPN strains during the same period in the same hospital usually belonged to the same ST clone.Conclusions MLST of CR-KPN showed 18 sequence types,of which ST11 was the predominant type.Clinical data indicated that the prevalent CR-KPN strains during the same period in the same hospital usually belonged to the same ST clone.This suggests the potential of local CR-KPN outbreak.The ICU patients and those receiving mechanical ventilation may be prone to CRKPN (especially ST11) infection.Such patients should be managed appropriately.