Prevalence of 0157: H7 and non-0157 E. coli in Iranian domestic sheep

Abstract

The aim of the present study was the isolation of both E. coli 0157 and non-0157 in sheep. Verotoxins (VT) 1, 2 and eae genes were tested for this propose. Sheep faces are an important source of Shiga toxin-producing Escherichia coli (STEC). Escherichia coli 0157:117 is a highly virulent food-borne pathogen and threat to public health. Rectal swab samples from sheep were collected during 2009-2010. Conventional plating and Polymerase Chain Reaction (PCR) were carried out according to virulence factors (Stxl, Stxl and eaeK).There significant differences between prevalence of STEC and session were observed. It was at highest in spring and late summer. Six (3.92%) sheep carcasses were contaminated by E. coli 0157:117.Only six samples were positive by PCR specific for the VT2gene and produced verocytotoxin VT2, whereas all isolates were negative for the presence of VT1 and eae virulence genes considered. Geographical variations and season may be influenced in the prevalence rate. The composition of the gastrointestinal flora may be changed by different diet and, therefore 0157 STEC rate in sheep and lamb was different. Iranian sheep indicated as a natural host of E. coli 0157 strains therefore, may be potentially pathogenic for humans. This is the first report of E. coli 0157 detection from sheep in Iran. © 2014 Asian Network for Scientific Information.