TY - JOUR AU - Tayh, Ghassan AU - Boubaker, Salma Mariem AU - Ben Khedher, Rym AU - Jbeli, Mounir AU - Ben Chehida, Faten AU - Mamlouk, Aymen AU - Dâaloul-Jedidi, Monia AU - Messadi, Lilia PY - 2022/08/30 Y2 - 2024/03/28 TI - Prevalence, virulence genes, and antimicrobial profiles of Escherichia coli O157:H7 isolated from healthy cattle in Tunisia JF - The Journal of Infection in Developing Countries JA - J Infect Dev Ctries VL - 16 IS - 08 SE - Original Articles DO - 10.3855/jidc.15855 UR - https://jidc.org/index.php/journal/article/view/36099374 SP - 1308-1316 AB - <p>Introduction: Shiga toxin-producing <em>Escherichia coli </em>(STEC) O157:H7 is associated with intestinal infection in humans and is considered an important cause of food-borne diseases. The aim of the study was to assess the incidence of <em>E. coli</em> O157:H7 in fecal samples of healthy cattle collected in slaughterhouses (n = 160) and from five farms (n = 100).</p><p>Methodology: <em>E. coli</em> isolates were detected on MacConkey agar. A total of 236 <em>E. coli</em> isolates were recovered from fecal samples of healthy cattle. We used sorbitol MacConkey medium to detect non-sorbitol fermenting colonies. These bacteria were examined for the presence of O157:H7 antigen by latex agglutination. The isolation of <em>E. coli</em> O157:H7 has been confirmed with PCR amplification of <em>rfbEO157</em> and <em>fliCH7</em> specific genes for serogroup O157 and with multiplex PCR of <em>stx1, stx2</em>, <em>eaeA,</em> and <em>ehxA</em>. All isolates were examined for their susceptibility to 21 antibiotics by the disc diffusion method.</p><p>Results: Of the 236 <em>E. coli</em> isolates, 4.2% (10/236) were positive for STEC O157:H7. Shiga toxin gene (<em>stx2</em>) and <em>ehxA</em> were present in 70% of isolates, <em>stx1</em> and <em>eae </em>were confirmed in 60% of the isolates. Other virulence factors screened (<em>fimH</em>, <em>sfa/focDE</em>,<em> cdt3</em>,<em> traT</em>,<em> iutA, </em>and <em>hlyA</em>) were present among the 10 isolates. All <em>E. coli</em> O157:H7 isolates were sensitive to amoxicillin/clavulanic acid, cefotaxime, cefepime, aztreonam, colistin, and sulfamethoxazole/trimethoprim. All isolates belong to the phylo-group E.</p><p>Conclusions: This is the first study of the incidence of <em>E. coli</em> O157:H7 in cattle in Tunisia. Our finding proves the existence of STEC O157:H7 in healthy animals producing food for human consumption which could be a source of food-borne disease.</p> ER -