肺炎克雷伯菌耐药表型及分子分型特征分析

Analysis of drug-resistance phenotypes and molecular typing characteristics of Klebsiella pneumoniae

目的探讨肺炎克雷伯菌耐药表型及通过脉冲场凝胶电泳(PFGE)技术分析其分子分型,为完善肺炎克雷伯菌分子流行病学特征提供依据。方法收集2018年1-12月肇庆市第二人民医院非重复分离的51株肺炎克雷伯菌为研究对象,采用微量肉汤法进行药敏试验;采用改良产碳青霉烯酶灭活试验(mCIM)检测CRKP表型;采用PFGE进行分子分型,建立PFGE DNA指纹图谱数据库,并运用Bionumeries6.6生物软件进行聚类分析。结果51株肺炎克雷伯菌根据耐药谱可以分为4个耐药表型,其中产超广谱β-内酰胺酶肺炎克雷伯菌(产ESBLsKP)28株(54.9%)、耐碳青霉烯酶类肺炎克雷伯菌(CRKP)4株(7.8%)、多重耐药肺炎克雷伯菌(MDRKP)9株(17.7%)、高毒力肺炎克雷伯菌(HvKP)10株(19.6%)。PFGE聚类分析结果显示,51株菌株间相似度为47.8%~100.0%,可分为47个PFGE型别,PFGE型别相似度>85.0%共10株,其中Ⅰ、Ⅱ、Ⅲ、Ⅳ型具有100.0%相同PFGE图谱,可以视为4个具有分子流行病学意义的单一克隆群。结论肇庆市第二人民医院肺炎克雷伯菌耐药表型以产ESBLsKP为主,PFGE分型呈多样性,并存在院内散发感染风险,需要注意菌株型别变异趋势。

Objective To investigate the drug resistance phenotypes of Klebsiella pneumoniae(KP)and analyze its molecular typing by using the pulsed-field gel electrophoresis(PFGE)so as to provide a basis for perfecting the molecular epidemiological characteristics of KP.Methods Fifty-one strains of KP isolated from the Zhaoqing Municipal Second People′s Hospital from January to December 2018 were selected as the research objects.The drug susceptibility test was performed by using microbroth dilution method(MIC).The CRKP phenotype was detected by adopting the modified carbapenem inactivation method(mCIM),and the molecular typing of KP was carried out by using PFGE and the PFGE DNA fingerprinting database was established,the clustering analysis was performed by using the Bionumeries 6.6 biologic software.Results Fifty-one strains of KP could be divided into 4 drug-resistant phenotypes according to the drug resistance spectrum,in which extended spectrum beta-lactamases KP(ESBLsKP)had 28 strains(54.9%),carbapenem resistant KP(CRKP)had 4 strains(7.8%),multidrug resistant KP(MDRKP)had 9 strains(17.7%),hypervirulent KP(HvKP)had 10 strains(19.6%).The PFGE clustering analysis result showed that the similarity of 51 strains was 47.8%-100.0%,and the 47 PFGE subtypes were identified,the PFGE genotype similarity>85.0%,totaled 10 strains.Among them,typeⅠ,typeⅡ,typeⅢand typeⅣhad 100.0%the same PFGE maps,which could be regarded as four single clones with molecular epidemiological significance.Conclusion ESBLsKP is the main drug resistance phenotype in Zhaoqing Municipal Second People′s Hospital.PFGE subtypes show diversity and have the risk of nosocomial sporadic infection.It is necessary to pay attention to the variation trend of strain types.