Detection of Brucella spp. in Dairy Products by Real-Time PCR

Background and Objectives: Brucella is an intracellular gram-negative bacterium that can infect many kinds of mammals like humans, sheep, cattle, etc. Brucellosis is a contagious occupational disease caused by Brucella spp. that affects individuals who have close contact with infected animals. The clinical features of Brucellosis are not disease-specific and almost every organ can be affected. This zoonotic disease is a great health concern and economically important in many countries, such as Iran. The aim of this study was to detect Brucella spp. in pasteurized and non-pasteurized dairy products. Methods: In this study, 208 samples, including goat, sheep, and cow raw and pasteurized milk as well as pasteurized and non-pasteurized cheese, were collected in Tehran province. The DNA was extracted, and then the real-time PCR was used for detection of the Brucella spp. gene. Results: The prevalence of Brucella spp. contamination in the dairy products was: 45.5% in goat's rawmilk, 39.1% in non-pasteurized cheese, 27.3% in sheep's raw milk, 26.3% in cow's raw milk, 25% in pasteurized cheese, and 14.7% in pasteurized milk. Conclusions: Rapid and exact detection of pathogens in dairy products is the most significant factor to prevent foodborne diseases. In addition, the real-time PCR assay is sensitive and specific enough to detect a low number of Brucella spp. in dairy products.