Detection of Brucella spp. in unpasteurized cow milk by polymerase chain reaction (PCR)

Brucellosis is a zoonosis caused by bacteria of the genus Brucella. Man infection occurs through contact with reproductive secretions as placenta and its lochia, semen and penile secretion of infected animals or by consuming unpasteurized milk and dairy products. With the objective of investigating the presence of bacteria in milk, 30 samples of raw milk sold illegally in the region of Botucatu, São Paulo, Brazil, as well as 50 samples of milk delivered to a dairy industry previously to its pasteurization were evaluated by the polymerase chain reaction (PCR) technique. Of the 80 samples analyzed, 10 samples (12.5%) were positive and 70 (87.5%) were negative. Among the positive samples, 5 (16.6%) were from illegal traders and other 5 (10%) were obtained from the dairy industry. Brucella spp. positivity shows that the pathogen is representatively present in Botucatu, São Paulo, Brazil, and the risk associated to public health due to the commercialization of illegal products without pasteurization is real.布鲁氏菌病（Brucellosis）是由布鲁氏菌属（Brucella）细菌引发的人畜共患病。人类感染可通过接触受感染动物的生殖分泌物（如胎盘及其恶露、精液与阴茎分泌物），或饮用未经巴氏灭菌（pasteurization）的牛奶及乳制品而致病。为调查牛奶中该病原菌的存在情况，研究人员采用聚合酶链式反应（PCR）技术，对巴西圣保罗州博图卡图地区非法售卖的30份生乳样本，以及某乳品企业巴氏灭菌前收集的50份生乳样本开展了检测。在80份受检样本中，10份（占比12.5%）呈阳性，70份（占比87.5%）呈阴性。其中阳性样本里，5份（16.6%）来自非法商贩，剩余5份（10%）取自该乳品企业。布鲁氏菌属（Brucella spp.）的阳性检出结果证实，该病原体在巴西圣保罗州博图卡图地区真实存在，未经巴氏灭菌的非法商业化流通乳制品所带来的公共健康风险切实存在。