<b>Detection of </b><b>Shiga toxin-producing </b><b><i>Escherichia coli</i></b><b> O157 and non-O157 </b><b>from retail </b><b>imported frozen beef marketed in Saudi Arabia</b>

Shiga toxin-producing Escherichia coli (STEC) and E. coli O157:H7 are responsible for many foodborne outbreaks worldwide. Both E. coli O157 and non-O157 are causing life-threatening complications, such as hemolytic colitis and hemolytic uremic syndrome, which can result in kidney failure. This study was conducted to determine the presence of STEC and E. coli O157 in imported frozen beef marketed in the Eastern Province of Saudi Arabia using immunomagnetic beads (IMB) and multiplex-PCR. In this study, a total of 201 frozen beef samples were purchased from different supermarkets in the Eastern Province of Saudi Arabia and enriched in tryptic soy broth (TSB). One-milliliter portions from enriched samples in TSB were mixed with immunomagnetic beads (IMB) coated with specific antibodies against E. coli O157 O antigen, separated beads with captured bacteria streaked on CHROMagar O157, and Sorbitol MacConkey (SMAC) agar. The extracted DNA template was examined for potential virulence gene markers (stx-1, stx-2, and eae) using multiplex-PCR. ERIC-PCR DNA fingerprinting was used to identify the clonal relationship among the strains isolated from frozen beef imported from different countries.