Prevalence of Brucella species in unpasteurized dairy products consumed in Shiraz province using PCR assay

The consumption of milk and unpasteurized dairy products contaminated with Brucella bacteria is one of the most important ways of brucellosis transmission to humans. The principal goal of this study was to determine the prevalence of Brucella abortus (B. abortus) and Brucella melitens (B. melitens)in unpasteurized dairy products consumed in Shiraz province. In this study conducted in 2016, 238 unpasteurized dairy products including 48 raw milk, 48 yogurt, 46 cheeses, 48 dough and 48 ice cream samples, were purchased from the retail market in Shiraz province and were examined by a specific PCR assay. This study showed positive 5/04% out of 238 unpasteurized dairy products including 9 out of 48 (18/75%) raw milk samples and 3 out of 48 (6.25%) yogurt samples). Contamination was not detected in samples of dough, cheese and traditional ice cream. The results also showed that among 12 positive samples, 6 samples were contaminated with B. abortus (including 4 milk samples  and 2 yogurt samples), 2 samples were contaminated with B. melitensis (including 2 Milk samples) and 4 samples were contaminated simultaneously with B. abortus and B. melitensis (including 3 milk samples and 1 yogurt sample). The present study suggests the unpasteurized dairy products as the major sources of brucellosis in Shiraz province, South of Iran; thus, to prevent brucellosis in human, the consumption of pasteurized milk and dairy products is highly recommended.