Prevalence of verocytotoxin-producing E. coli in sheep meat at a slaughterhouse

Abstract

Sheep play important roles in the spread of pathogenic Escherichia coli that can cause severe diseases in humans. The aim of the present study was to evaluate the prevalence of verocytotoxin-producing E. coli (VTEC) in various samples from Sarda sheep using a molecular screening test and to define the virulence profiles of isolates using multiplex PCR. A total of 380 different ovine samples (fleece, carcass surface, and mucosal gut) were analyzed by direct PCR screening for the presence of stx 1 e stx 2 genes. Virulence factors (stx 1, stx 2, and eae) from the strains, isolated by immunomagnetic separation (IMS)-based cultivation techniques (e.g., CT-SMAC, CT-RMAC, and EHLY agar), were determined by multiplex PCR. An overall prevalence of 11.1% (adults 14%, lambs 7.8%) was found by direct PCR. VTEC occurrence was 18.9% in fleece, 14.7% on carcasses, and 10.5% in mucosal gut. According to the multiplex-PCR results, the following values were obtained: 43.4% VTEC (stx 1, stx 2, stx 1 + stx 2, stx 2 + eae, and stx 1 + stx 2 + eae), 30.3% EPEC (stx 1 -/stx 2 -/eae+), and 26.4% negative for all genes examined (stx 1 -, stx 2 -, eae-).