Which of the following is NOT among the six pathogens most often discussed as targets in milk safety and pasteurization?

• A. Staphylococcus aureus
• B. Listeria monocytogenes
• C. Salmonella spp.
• D. Campylobacter jejuni

Answer: (A)

The main idea here is that pasteurization targets the most impactful, heat-sensitive pathogens that can contaminate milk and cause illness. The six commonly highlighted hazards in dairy safety are Listeria monocytogenes, Salmonella spp., Campylobacter jejuni, Escherichia coli O157:H7, plus two other significant zoonotic threats (often Brucella spp. and Mycobacterium bovis, depending on the course). Staphylococcus aureus isn’t typically listed among those six because, in the pasteurization context, the focus is on pathogens that pose a direct and well-documented risk from viable bacteria in milk that heat processing reduces. S. aureus can be present in milk, but its risk is more closely tied to pre-pasteurization hygiene and animal health, and its toxin-related hazards aren’t addressed by pasteurization alone in the same way as the other six. So Staphylococcus aureus is the one not among the standard six.