Prevalence of Pathogenic Microorganisms in Traditional Dairy Products of Mashhad, Iran

Background: Milk and dairy products have an essential role in human health; however, they are easily contaminated and are likely to transfer pathogenic foodborne bacteria. Since traditional dairy products are very popular and are frequently used by the community, the aim of this study was to assess the contamination rate of raw milk and traditional dairy products by pathogenic bacteria and mold in Mashhad, Iran. Methods: A total of 200 samples were collected from five districts of Mashhad, Iran in the summer of 2018. Samples were tested for Coliform, E. coli, S. aureus, Salmonella spp, Listeria monocytogenes, mold, and yeast according to the Iranian national standard methods. Results: Results showed that 65% of the samples were positive for at least one pathogenic bacteria. The prevalence of Coliform, Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Salmonella spp., molds, and yeast in all dairy products were 62.5%, 32.5%, 59.5%, 27.5%, 26%, and 100% respectively. Conclusion: The results indicated that considerable numbers of traditional dairy products were contaminated with pathogenic microorganisms in Mashhad, Iran which emphasized the need for stricter hygienic rules and general education about the safety of traditional foods.