伊犁地区肉牛源产志贺毒素大肠杆菌的血清型和ERIC-PCR基因型研究
Study on serotype and ERIC-PCR typing of Shiga toxin-producing Escherichia coli in Yili area
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摘要: 目的:了解产志贺毒素大肠杆菌在伊犁地区肉牛养殖环境和加工环节中的污染状况及其遗传多样性,为产业链中食源性致病性大肠杆菌的风险监测和控制提供基础数据。方法:采用传统方法和PCR方法对养殖环节的饲草料和粪便及屠宰环节的553份样品进行产志贺毒素大肠杆菌的污染调查,对分离鉴定的产志贺毒素大肠杆菌进行7种常见血清型（O145、O157、O45、O103、O111、O26、O121）的PCR检测和ERIC-PCR的基因分型。结果:检测553份样品中有39株编码志贺毒素基因,产志贺毒素大肠杆菌（STEC）的检测率是7.1%。常见血清型PCR检测中血清型O111有2株菌,检出率是5.1%;O145有5株菌,检出率是12.8%。ERIC-PCR基因分型产志贺毒素大肠杆菌有10种基因亚型,分成3簇,A簇有23株菌,相似性在59%100%,表明这些菌株之间的亲缘关系较近。结论:伊犁地区肉牛粪便是产志贺毒素大肠杆菌的污染源,这些菌株的亲缘关系较近。Abstract: Objective: To investigate the food contamination and genetic diversity of the Shiga toxin producing Escherichia coli in cattle breeding and processing environment in Yili area. To provide the basic data for risk monitoring and control in the industrial chain of pathogenicity E. coli associated foodborne disease. Methods: According to the national standard and the polymerase chain reaction ( PCR) method detected the contamination of Shiga toxin-producing E. coli in the 553 samples including the breeding link forage and faeces, slaughter link. The isolation and identification STEC strains were used to detect the 7 common serotypes ( O145, O157, O45, O103, O111, O26, O121) with PCR methods and ERIC-PCR genotyping. Results:There were 39 strains encoding Shiga toxin gene in 553 samples.The detection rate of STEC was about 7.1%.The detection of common serotype PCR have 2 strains and 5 strains in the serotype O111 and O145, the detection rate was about 5.1% and12.8%, respectively.ERIC-PCR genotyping of STEC had 10 genetic subtypes and divided into 3 clusters.There were 23 strains in A cluster, the similarity was from 59% to 100%, which indicated that the relationship among these strains was relatively close. Conclusion: The beef cattle feces would be the source of Shiga toxin-producing E. coli and the genetic relationship of these strains was close in Yili area.
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