Serogroups, subtypes and virulence factors of shigatoxin-producing Escherichia coli isolated fromhuman, calves and goats in Kerman, Iran

Aim: The present study was conducted to detect the occurrence, serogroups, virulencegenes and phylogenetic relationship of shiga toxin-producing Escherichia coli (STEC) inhuman, clave and goat in Kerman (southeast of Iran).Background: STEC have emerged as the important foodborne zoonotic pathogenscausing human gastrointestinal disease and confirming the risk to public health.Methods: A total of ۶۷۱ fecal samples were collected from diarrheic patients (n=۳۹۵) andhealthy calves (n=۱۵۶) and goats (n=۱۲۰) and screened for the presence of stx gene.Furthermore, the prevalence of stx۱ and stx۲ variants, serotypes (O۱۵۷, O۱۴۵, O۱۰۳, O۲۶,O۱۱۱, O۹۱, O۱۲۸, and O۴۵), phylogenetic groups and the presence of ehxA, eae, hylA, ihaand saa virulence genes were studied.Results: Prevalence of STEC in human diarrheic isolates was ۱.۳% (۵ isolates), in claveswas ۲۶.۳% (۴۱ isolates) and in goats was ۲۷.۵% (۳۳ isolates). stx۱ gene was the mostprevalent variant and detected in ۷۵ isolates. Furthermore, stx۱c was the most predominantstx subtype, found in ۵۶ isolates. The ehxA identified in ۳۶ (۴۵.۶%) isolates, followed by iha ۵(۶.۳%), eaeA ۴ (۵.۱%), hlyA ۲ (۲.۵%) and saa ۲ (۲.۵%). Most of the isolates belonged tophylogroup B۱. Only two O۲۶ and one O۹۱ isolates were detected in our study.

کلیدواژه ها:

Shiga toxin-producing E. coli ، serogroup ، virulence factors.