<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 <i>Escherichia coli</i> (STEC) and <i>E. coli</i> O157:H7 are responsible for many foodborne outbreaks worldwide. Both <i>E. coli</i> 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 <i>E. coli</i> 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 <i>E. coli </i>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 (<i>stx-1</i>, <i>stx-2</i>, and <i>eae</i>) 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.<br>