en Food Safety and Hygiene Food Safety and Hygiene پژوهشي Original Article <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:times new roman;"><strong>Background:</strong> <em>Yersinia enterocolitica</em> (<em>Y. enterocolitica</em>) has a wide range of clinical, animal, food, and water sources. Most studies have indicated that food is the most common source of this organism. The present study aimed to evaluate the virulent genes of <em>Y. enterocolitica</em> isolated from dairy products in Iran.<br> <strong>Methods: </strong>The virulence of <em>Y. enterocolitica</em> biotypes was investigated, which was isolated from 38 cheese and 33 raw milk samples in the northeast of Iran. In total, six virulence-related genes were evaluated, including <em>ail</em>, <em>inv, yadA</em>, <em>myfA</em>, <em>ystA</em>, and <em>ystB</em> in 1A, 1B, and 5 <em>Y. enterocolitica</em> biotypes.<br> <strong>Results</strong>: In the isolates of the 1A biotype, <em>ystB</em> was the most frequent gene (86.95% and 38.46% in cheese and raw milk, respectively). In the 1B biotype, the most frequently isolated gene was <em>yadA</em> (92.30% and 66.66% in cheese and raw milk, respectively). In all the isolates, the least frequently isolated gene was <em>ail</em>, followed by <em>myfA.</em><br> <strong>Conclusion:</strong> According to the results, the presence of virulence genes in the <em>Y. enterocolitica</em> strains isolated from dairy products suggested that these strains could pose significant risk to public health if dispersed in susceptible human population.</span></span></div> Yersinia enterocolitica, Virulence, Dairy products 72 78 http://jhehp.zums.ac.ir/browse.php?a_code=A-10-274-1&slc_lang=en&sid=1 Milad Tavassoli tavassolim951@mums.ac.ir 10031947532846009707 10031947532846009707 No Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. Abdollah Jamshidi ajamshid@um.ac.ir 10031947532846009708 10031947532846009708 No Department of Food Hygiene, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran. Fahimeh Movafagh movafagh1391@yahoo.com 10031947532846009709 10031947532846009709 No Food Hygiene and Quality Control, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran. Asma Afshari asmafshr@gmail.com 10031947532846009710 10031947532846009710 Yes Department of Nutrition, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.