Detection of Brucella abortus from Retail Raw Milk Samples from Quetta, Pakistan

Abstract

Brucellosis is the most significant zoonotic bacterial disease with huge economic impacts in the livestock production sector, and is a public health menace worldwide, especially in developing countries such as Pakistan. Brucella abortus, the causative agent of bovine brucellosis, usually infects humans through the ingestion of contaminated raw milk and its products. Consumption of contaminated milk is the source of human infections in those areas where the practice of consuming raw milk is common, and no preventive measures have been taken yet. This work was performed to find out the prevalence rate of B. abortus in retail raw milk from milk shops in Quetta, Pakistan, by serological, microbiological, and molecular techniques. A total of 100 samples of raw milk were tested. Out of them, 24% were found positive by the Milk Ring Test (MRT), and 20% were positive by the Enzyme-Linked Immunosorbent Assay (ELISA). Bacteriological and molecular detection showed the presence of B. abortus in 15% of the samples. Isolated colonies possessed the typical characteristics of B. abortus. The presence of living B. abortus in raw milk indicated the exposure of consumers to the disease by ingesting unprocessed milk. These results highlight the importance of enhanced surveillance and testing of bovine brucellosis, milk quality monitoring, better management practices on farms, and public education on the risks of consuming raw milk to prevent zoonosis and foodborne illness.