Study on serotype and ERIC-PCR typing of Shiga toxin-producing Escherichia coli in Yili area

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.