The prevalence of Salmonella, Campylobacter, and Yersinia spp. in the food chain, and the more recent emergence of Listeria monocytogenes and hemorrhagic Escherichia coli as foodborne pathogens, are of public health concern. The ability of some of these bacterial agents to grow in milk and dairy products, to survive prolonged periods of refrigerated storage, and to withstand thermal treatments of raw milk at subpasteurizing temperatures, place new emphasis on the need for stringent control of milk processing operations and plant environment. Mandatory use of pasteurized milk may provide the only viable option for production of pathogen-free milk products.
1Presented at the International Seminar On Modern Microbiological Methods, Santander, Spain (22–24 May, 1989)