A review of nontuberculous mycobacteria presence in raw and pasteurized bovine milk

Nontuberculous mycobacteria (NTM), also known as environmental mycobacteria due to their ubiquitous nature, are opportunistic human pathogens of public health concern. They are the causative agent of lymphadenitis in children; pulmonary, skin, and soft tissue infections; and have been linked to Crohn's disease. Human-tohuman transmission is rare and as such it is essential to identify potential environmental sources and routes of exposure. This review explores studies written in English investigating the presence of NTM in pasteurized and unpasteurized milk over the last 20 years. Globally, it was demonstrated that NTM have been detected from milk products in Argentina, Austria, Brazil, Chile, Cyprus, the Czech Republic, Denmark, Iran, Iraq, India, Ireland, Italy, Switzerland, Tanzania, Turkey, UK, and U.S. We explored the relationships among the specific NTM species identified, pasteurized and unpasteurized milk, and different detection methods. Both experimental studies and detection from commercial milk suggests the NTM can survive the pasteurization process. Further research is required to explore the potential role of milk as a possible route of exposure to NTM and to identify potential management and control strategies.