Development of an enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) to detect and genotype enterotoxigenic Escherichia coli of calf origin

Abstract

We develop an enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) DNA fingerprinting technique for genotyping enterotoxigenic Escherichia coli(ETEC) in calves. Using the ERIC-PCR, we detected 66 ETEC strains in calves isolated from 11 farms. The ETEC strains could be grouped into 17 types, with type D predominant. The ERIC-PCR system is an efficient method for identification, typing and tracking of ETEC. Serotyping using a specific O antigen revealed 15 serotypes, with serotype O111 most prevalent (21.2%). We were unable to serotype 21.5% of the ETEC strains we had previously identified by ERIC-PCR. Our results indicate that some ETEC strains had identical genotypes, however their serotype might differ and vice versa. The ERIC-PCR method is rapid, sensitive, repeatable and reliable, and we believe it should be applied for the genotyping of ETEC in calves. Key Words: Calf, enterotoxigenic Escherichia coli, ERIC-PCR, genotyping, serotyping.