碳青霉烯类耐药肺炎克雷伯菌多位点序列分型和不同ST分型感染患者的临床特点

摘要

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.%目的 对临床分离的碳青霉烯类耐药肺炎克雷伯菌(CR-KPN)进行多位点序列分型(MLST),同时研究不同ST分型感染患者的临床特点.方法 收集2013年1月-2015年6月辽宁省为主5所医院临床分离的6]株CR-KPN,采用微量肉汤稀释法测定受试菌株对14种抗菌药物的敏感性.应用PCR基因扩增技术及DNA测序方法对受试菌株进行碳青霉烯酶基因检测.通过对受试菌株进行MLST,探讨其克隆相关性和分子流行病学特征.同时分析不同ST分型下CR-KPN的耐药特点、耐药机制及菌株感染的临床特点.结果 MLST分型显示61株CR-KPN共有18种ST分型,ST11为优势型别(53.3％),研究同时发现这部分ST11型菌株更容易对碳青霉烯类抗生素耐药且MIC值较高,大部分产KPC-2型碳青霉烯酶.单因素分析提示ST1 1组患者在ICU接受治疗所占的比例及机械通气的使用率高于非ST11组,差异具有统计学意义.其他ST型中ST2033、ST2135、ST2193、ST2194、ST2195、ST2196为世界范围内首次注册,其中ST2193、ST2194、ST2195与ST11有密切的亲缘性.临床资料提示同一所医院同一时期以相同克隆流行为主.结论 MLST显示CR-KPN共有18种ST型别,ST11为优势型别,结合临床资料发现同一所医院同一时期以相同克隆流行为主,提示CR-KPN有局部播散的风险.鉴于临床资料分析提示接受过ICU治疗和机械通气的患者容易发生CR-KPN菌株(特别是ST11型)感染的风险,此类患者应引起临床的广泛重视.