First report of the prevalence of Shiga toxinproducing Escherichia coli in ground beef in Quindío, Colombia

Abstract

Introduction. Shiga toxin-producing Escherichia coli (STEC) is a foodborne pathogen associated with clinical cases of diarrhea in humans. Its main virulence factors are the Shiga toxins (Stx1 and Stx2). Cattle are the main reservoir of STEC, and many outbreaks in humans have been related to the consumption of undercooked ground beef contaminated with this pathogen.Objective. To determine the prevalence of STEC in ground beef commercialized in all the butcher shops of a township in the department of Quindío and to characterize the virulence genes of the strains found.Materials and methods. Thirty ground beef samples were taken in three different times; stx genes and other STEC virulence factors (eae, ehxA, saa) were detected by multiplex PCR.Results. The overall prevalence of STEC was 33.33 % (10/30 positive samples). We isolated eight non-O157 (LEE-negative) strains with four different genetic profiles: stx2 / stx2-ehxA-saa / stx1-stx2-ehxA-saa / stx1-saa.Conclusion. This is the first report on the prevalence of STEC in ground beef in a township in the department of Quindío.