福建省非典型肠致病性大肠埃希菌的分子特征研究  

Molecular characteristics of atypical enteropathogenic E.coli isolated in Fujian

作　　者：陈爱平[1,2,3] 李曲文[1] 林杰[1] 陈建辉[1] 杨劲松[1] 王灵岚[1] 严延生[1] 

机构地区：[1]福建省疾病预防控制中心,福建福州350001 [2]福建省人兽共患病研究重点实验室 [3]福建医科大学公共卫生学院教学基地

出　　处：《中国预防医学杂志》2014年第3期216-220,共5页Chinese Preventive Medicine

基　　金：福建省医学创新课题(2011-CXB-19)

摘　　要：目的研究福建省非典型肠致病性大肠埃希菌(aEPEC)菌株的毒力基因特征和菌株间的遗传相似度;结合菌株的背景资料分析不同的分子特征对aEPEC流行的影响。方法运用PCR技术进行系列的相关毒力基因扩增;同时运用脉冲场凝胶电泳分子分型技术,对福建省2010-2012年分离的aEPEC菌株进行脉冲场凝胶电泳(PFGE)分子分型。结果分离30株实验菌株毒力基因的检测呈阳性的分别为:b112153.3%(16),yiaA36.7%(11),set/ent、nleB、nleE均为30%(9),lpfAR141 23.3%(7),efa/lifA20%(6),ehxA3.33%(1);其余毒力基因均未检出;93.3%(28)菌株不同程度地携带有相关的毒力因子。29株菌按照100%的相似度分为15个PFGE型别(P1-P15);其中存在4组不同的PFGE簇(I-Ⅳ),相同PFGE簇的病例在发病的时间和地区上有聚集性,同时相同簇内菌株的毒力基因谱也表现相同。结论 b1121、yiaA和EHEC毒力岛OI-122相关基因(efa1/lifA,nleB,nleE,set/ent)在福建省aEPEC菌株中携带率较高。非典型肠致病性大肠埃希菌的毒力谱表现为多样性,基因组也呈现遗传多态性;同时PFGE分析发现福建省存在由aEPEC新发病原菌引起的聚集性病例。Objective To analyze the molecular characteristics of atypical enteropathogenic Escherichia coli（aEPEC）isolated in Fujian,including the analysis of virulence genes and genetic relationship among different aEPEC isolates. Methods A total of 30aEPEC isolates were collected in Fujian from 2010to 2012.The virulence-related genes were amplified by PCR and their genetic relationships were determined by pulsed-field gel electrophoresis（PFGE）. Results Out of 15virulence genes,eight were amplified by PCR which were b1121（53.3%）,yiaA（36.7%）,set/ent（30%）,nleB（30%）,nleE（30%）,lpfAR141（23.3%）,efa/lifA（20%）and ehxA（3.33%）.93.3% of isolates harbored virulence-related genes.Fifteen PFGE patterns（P1-P15）were observed in 29strains according to 100%similarity,and were grouped in 4PFGE clusters（I-IV）.Cases within each cluster showed similar onset time and geographic origination,while strains within each cluster shared identical virulence-gene profiles. Conclusions Majority of atypical enteropathogenic E.coli strains isolated in Fujian harbor virulence-related genes,especially b1121,yiaA and other genes（efa1/lifA,nleB,nleE and set/ent）in the pathogenic island OI-122of EHEC.Meanwhile,aEPEC strains display considerable heterogeneity in virulence-gene profiles and genome structures.Some clustered cases with new aEPEC strains has been also identified in Fujian by PFGE.

关 键 词：非典型肠致病性大肠埃希菌 毒力基因 PFGE 

分 类 号：R378[医药卫生—病原生物学]