Distribution Pattern of EcoR Phylogenetic Groups Among Shiga Toxin-Producing and Enteropathogenic Escherichia coli Isolated From Healthy Goats

Escherichia coli can be categorized into four major phylogenetic groups (A, B1, B2, and D) based on presence or absence of three markers including two genes (chuA and yjaA) and an anonymous DNA fragment designated TSPE4.C2. Also, these groups are divided into seven phylogenetic subgroups A0, A1, B1, B22, B23, D1, and D2. This study aimed to determine the distribution pattern of phylogenetic groups in Shiga Toxin-Producing Escherichia coli (STEC) and Enteropathogenic Escherichia coli (EPEC) isolated from asymptomatic goats in Kerman city, Iran. Two hundred and fifty fecal samples were obtained from healthy goats. All isolates were subjected to detection of phylogenetic markers chuA, yjaA and DNA fragment TspE4.C2 and virulence genes stx1, stx2 and eae. In summary, among all isolates phylo-group B1 was the most prevalent (57.6%) and other phylo-groups were A1 (20.4%), A0 (18.4%), D1 (2.8%), and B22 (0.8%). There was no isolate in B23 and D2 subgroups. Fifty samples (20%) possessed at least one of the tested virulence genes: stx1 (12%), stx1/stx2 (4%), eae (2.8%), stx1/eae (0.8%), and stx2 (0.4%). Thus, 41 (16.4%) STEC, 7 (2.8%) EPEC and 2 (0.8%) Enterohemorrhagic Escherichia coli (EHEC) strains were isolated and allocated into four phylogenetic subgroups A0 (16%), A1 (12%), B1 (68%), and D1 (4%). Based on 250 fecal samples obtained from goats in industrial slaughterhouse of Kerman City, goats may be a potential reservoir of STEC in Kerman and B1 followed by A are the most prevalent phylogenetic groups among STEC and non-STEC isolates in this study.