腹泻病例中致泻性大肠埃希菌PCR毒力基因检测及分子分型分析  

PCR Virulence Gene Detection and Molecular Typing Analysis of Diarrheal Escherichia Coli in Diarrhea Cases

作　　者：沈昭宸 曹军[1] SHEN Zhaochen;CAO Jun(Department of Clinical Laboratory,Huishan Center for Disease Control and Prevention,Wuxi,Jiangsu 214000,China)

机构地区：[1]无锡市惠山区疾病预防控制中心检验科,江苏无锡214000

出　　处：《中国医药指南》2025年第6期35-38,共4页Guide of China Medicine

摘　　要：目的通过多重荧光定量PCR法及脉冲场凝胶电泳对腹泻病例致泻性大肠埃希菌(DEC)菌株进行毒力基因检测,耐药情况及分子分型分析。方法选取2021年1月至2023年12月无锡市惠山区疾病预防控制中心检验科接收的100例腹泻病例,对病例肛拭子标本通过多重荧光定量PCR法进行毒力基因检测,并对菌株进行耐药性检测,分析DEC毒力基因型、DEC流行情况与耐药情况及脉冲场凝胶电泳分子分型。结果本次共分离104株DEC,以EAEC型别居多,共计63株,其中携带astA/pic毒力基因59株;其次为ETEC,共计35株,其中携带estIa/esib毒力基因21株;EPEC为5株,携带eae毒力基因;EHEC为1株,携带Eae,stxl/stx2毒力基因。经过对100例腹泻病例进行分析发现,各个年龄段均可能感染DEC,其中≥60岁患者占比相对比较少,检出率主要集中在20~39岁,各个年龄段感染主要以EAEC为主;对104株DEC做抗生素敏感试验,结果发现,菌株对头孢他啶、亚胺培南敏感率分别为92.31%和99.04%,菌株在亚胺培南以外的药物中均出现一定的耐药性,其中氨苄西林最高,其次为四环素、萘啶酸、复方新诺明、头孢唑林、氯霉素;在104株DEC菌株中抽取16株采取限制性内切酶XbaI消化,通过脉冲场凝胶电泳对有效条带进行分析发现,在DNA分子水平上表现为高度多态性,同源性相对比较低,未发现完全相似的菌株,部分菌株在遗传相似度方面达到90%以上。结论致泻性大肠埃希菌患者中多以EAEC感染为主,患者往往对氨苄西林存在比较高的耐药率,各医院应引起高度重视,不断对PFGE分子分型数据库进行完善,加强疾病防控措施。Objective To detect virulence gene,drug resistance and molecular typing of diarrheal Escherichia coli(DEC)strains by multiplex fluorescence quantitative PCR and pulsed field gel electrophoresis.Methods A total of 100 cases of diarrhea received by the clinical Laboratory of Huishan Center for Disease Control and Prevention in Wuxi City from January 2021 to December 2023 were selected.The anal swabs of the cases were tested for virulence genes by multiple fluorescent quantitative PCR,and the strains were tested for drug resistance.The virulence factors of DEC,prevalence and drug resistance of DEC,and molecular typing of pulse field gel electrophoresis were analyzed.Results A total of 104 DEC strains were isolated in this study,mostly EAEC type,with a total of 63 strains.Among them,59 strains carried astA/pic virulence genes,followed by ETEC,a total of 35 strains,including 21 strains carrying estIa/esib virulence genes,5 strains carrying EPEC virulence genes,and 1 strain of EHEC carrying Eae,stxl/stx2 virulence genes.After analysis of 100 cases of diarrhea,it was found that DEC could be infected at all ages,among which the proportion of patients≥60 years old was relatively small,the detection rate was mainly concentrated in 20-39 years old,and EAEC was mainly infected at all ages.The antibiotic susceptibility test of 104 DEC strains showed that the susceptibility rate to ceftazidime and imipenem reached 92.31%and 99.04%,respectively.Ampicillin showed the highest resistance,followed by tetracycline,nalidixic acid,cotrimoxazole,cefzolin and chloramphenicol.Sixteen of 104 DEC strains were digested by restriction enzyme XbaI,and the effective bands were analyzed by pulse field gel electrophoresis.It was found that the DNA molecular level showed high polymorphism,relatively low homology,no completely similar strains were found,and some strains had genetic similarity of more than 90%.Conclusions EAEC infection is the main infection in patients with diarrhegenic Eschericemia,and patients often have a relatively high drug

关 键 词：腹泻 致泻性大肠埃希菌 多重荧光定量PCR法 毒力基因检测 脉冲场凝胶电泳 分子分型 

分 类 号：R446.5[医药卫生—诊断学]