Contamination of Bovine Milk With Brucella spp.: A Current Public Health Menace in Kurdistan Province of Iran

Abstract

Background: Brucellosis, a deteriorating zoonotic disease, is very common in most parts of Iran. Consumption of contaminated milk and dairy products is one of the most significant ways for transmission of the infections to human. Since the close rearing of cattle and sheep is practiced in Kurdistan province of Iran, the infection of cow with non-specific species is not out of mind. The present study aimed to determine the frequency of bovine milk contamination with zoonotic Brucella spp. Methods: A total of 240 milk samples, equally from traditional and industrialized dairy farms, were collected aseptically. Conventional microbiological method was used for isolation of the bacterium, followed by the genotypic identification of the isolates. Moreover, direct molecular processing of the samples was carried out for detection of the bacterial genome. The positive samples were further genotypically assessed to identify the contamination as Brucella abortus or Brucella melitensis. Results: In general, 16 (6.66%) and 15 (6.25%) of the samples were contaminated with Brucella spp. in phenotypic and genotypic methods, respectively. The proportion of contamination with B. abortus and B. melitensis in phenotypic and genotypic methods were 5% and 1.66%, and 5% and 1.25%, respectively. The overall rate of contamination in traditional milk samples was more than industrialized samples. Conclusions: Contamination of bovine milk with Brucella spp. is a serious threat to public health in the studied region. Continuous vaccination, application of test and slaughter policy, and presumption of pasteurized milk and dairy products are highly recommended.