耐碳青霉烯类肺炎克雷伯菌耐药基因及同源性分析

摘要

目的 了解急诊重症监护病房(ICU)分离耐碳青霉烯类肺炎克雷伯菌(CRKP)耐药基因携带情况和菌株同源性.方法 收集2015年7月至2016年8月分离自徐州医科大学附属医院急诊ICU的CRKP 19株,PCR检测碳青霉烯类耐药基因、超广谱β内酰胺类相关基因及头孢菌素类耐药基因;脉冲场凝胶电泳(PFGE)和多位点序列分型(MLST)进行菌株分子分型.结果 19株CRKP菌株中18株检出碳青霉烯类耐药基因,包括blaKPC-2型17株和blaNDM-5型1株;18株菌均携带ESBLs基因,其中blaSHV-12型8株、blaSHV-H型3株、blaSHV-2a型5株,blaTEM-1型15株、blaCTX-M-65型10株,blaCTX-M-15型3株,blaCTX-M-14及blaCTX-M-27型各1株;13株检出头孢菌素类耐药基因,且均为blaDHA-1型.PFGE分型显示19株CRKP可以分为4个型和4个亚型,包括A1型12株,A2型、A3型、A4型各1株,B型2株,C型及D型各1株.MLST显示ST11型15株,ST48型2株以及ST37型1株,1株菌未能分型.其中15株blaKPC-2阳性ST11型菌株PFGE分型为型别A.结论 我院急诊ICU存在携带blaKPC-2基因ST11型CRKP菌株克隆传播,应加强急诊ICU的耐药性监测以及病房的隔离和消毒.%Objective To understand the prevalence of resistance gene and homology of carbapenem-resistant Klebsiella pneumoniae (CRKP) isolated from ICU of emergency.Methods A total of 19 CRKP isolates were obtained from emergency ICU of the Affiliated Hospital of Xuzhou Medical University from July 2015 to August 2016.PCR was performed to screen the genes encoding carbapenemase,extended spectrum beta-lactamase (ESBL) and AmpC.Pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) were used for molecular typing of these bacterial strains.Results Among the 19 CRKP,carbapenemase-resistant genes were detectable in 18 CRKP isolates,including 17 isolates of harboring blaKPC gene and 1 strain of harboring blaNDM gene.All the 18 strains carried ESBLs genes which were identified as 8 blaSHV-12,3 blaSHV-11,5 blaSHV-2a,15 blaTEM-1,10 blaCTX-M-65,3 blaCTX-M-15,1 blaCTX-M-14 and 1 blaCTX-M-27.The 13 strains harboring cephalosporin-resistant genes were all identified as blaDHA-1.PFGE results revealed that the 19 CRKP strains were grouped into 4 types (A,B,C and D) and 4 subtypes(A1,2,3 and 4):A1 (n =12),A2(n =1),A3 (n=1),A4(n=1),B(n=2),C(n=1) and D(n=1).MLST showed that ST11 was the predominant sequence type (n=15) among the 19 CRKP strains,and ST48 (n =2),ST37 (n =1) and untyped (n =1) were also identified.The 15 blaKPC-2-producing CRKP ST11 clone shared the A type of PFGE pattern.Conclusion The report on CRKP suggested the dissemination of blaKPC-2-producing ST11 clone was existed in the ICU of emergency department in this hospital.The surveillance for drug-resistance and effective disinfectant quarantine measures should be strengthened.