院内耐阿米卡星肺炎克雷伯菌β-内酰胺类耐药基因的研究

Study on β-lactam resistant genes in nosocomial amikacin-resistant Klebsiella pneumonia

目的研究临床分离的耐阿米卡星肺炎克雷伯菌β-内酰胺类耐药基因的流行情况,为医院感染控制提供理论依据。方法采用WalkAway 96 PLUS全自动化微生物细菌分析仪对山东省2家医院2013年6月至2014年11月临床筛选出的27株非重复耐阿米卡星肺炎克雷伯菌进行细菌鉴定及药敏试验,用PCR法检测β-内酰胺类耐药基因,脉冲场电泳(PFGE)分析菌株之间的同源性,对不同PFGE的PCR阳性基因进行测序。结果27株耐阿米卡星肺炎克雷伯菌中,PFGE分为14种谱型,主要为E谱型(22.22%),其次为D谱型(11.11%)、H谱型(11.11%)和M谱型(11.11%),E谱型在2家医院存在相同的克隆流行株。β-内酰胺类耐药基因TEM-1、SHV-12、SHV-1、SHV-11、CTX-M-15、CTX-M-3、CTX-M-14、CTX-M-65、DHA-1、KPC-2和NDM-1携带率分别为100.00%、40.74%、11.11%、33.33%、22.22%、11.11%、14.81%、37.03%、51.85%、22.22%和3.70%。所有菌株都产携带超广谱β-内酰胺酶和(或)头孢菌素酶,对氨曲南、头孢唑啉、头孢夫新、头孢噻肟、头孢他啶均耐药。6株携带KPC-2碳青霉烯酶和1株携带NDM-1金属酶的耐阿米卡星肺炎克雷伯菌对亚胺培南、美罗培南和厄他培南均耐药。结论耐阿米卡星肺炎克雷伯菌多重耐药与同时携带多种β-内酰胺类耐药基因关系密切,院感部门应关注医院间耐药菌的传播。

Objective To study the prevalence situation ofβ-lactam resistant genes in clinically isolated amikacin-resistant Klebsiella pneumoniae,in orader to provide a theoretical basis for controlling the nosocomial infection.Methods Twenty-seven strains of non-repetitive amikacin-resistant Klebsiella pneumoniae clinically isolated in two hospitals of Shandong Province from June 2013 to November 2014 conducted the bacterial identification and drug-sensitivity tests by adopting the WalkAway 96 PLUS automatic microbial analyzer.Theβ-lactam resistant genes were detected by PCR.PFGE was used to analyze the homology among the bacterial strains.The PCR-positive genes of different PFGE were sequenced.Results Among the 27 strains of Klebsiella pneumoniae resistant to amikacin,PFGE was divided into the 14 spectral patterns,which were mainly the E spectral pattern(22.22%),followed by the D spectral pattern(11.11%),H spectral pattern(11.11%)and M spectral pattern(11.11%).The E spectral pattern had the same clonal strains in the two hospitals.The carrying rates ofβ-lactam resistant genes,including TEM-1,SHV-12,SHV-1,SHV-11,CTX-M-15,CTX-M-3,CTX-M-14,CTX-M-65,DHA-1 KPC-2 and NDM-1,were 100.00%,40.74%,11.11%,33.33%,22.22%,11.11%,14.81%,37.03%,51.85%,22.22%and 3.70%,respectively.All strains carried the extended-spectrum beta-lactamases and/or cephalosporins,and all were resistant to aztreonam,cefazolin,cefafosin,cefotaxime and ceftazidime.Six strains of Klebsiella pneumoniae carrying KPC-2 carbapenemase and one strain carrying NDM-1 metalloenzyme were resistant to imipenem,meropenem and ertapenem.Conclusion The multi-drug resistance of amikacin-resistant Klebsiella pneumoniae has close relation with simultaneously carrying multipleβ-lactam resistant genes.The same clone strains found in two hospitals alerts that the nosocomial infection department should pay attention to the spread of drug-resistant bacteria between hospitals.