Which of the following pathogens is associated with improperly handled dairy products?

Listeria is the correct choice in this context, as it is specifically associated with improperly handled dairy products, including unpasteurized milk and cheeses made from unpasteurized milk. This bacterium can thrive in refrigerated environments, which makes dairy products particularly susceptible to contamination and growth if proper hygiene and safety practices are not followed during processing, handling, and storage.

Listeria monocytogenes can cause listeriosis, a serious infection that primarily affects pregnant women, newborns, older adults, and individuals with weakened immune systems. This underscores the critical importance of stringent food safety practices in dairy production and handling to prevent such pathogen transmission.

While E. coli and Salmonella can also be linked to dairy products, they are more commonly associated with undercooked meats, contaminated vegetables, and raw milk in different contexts. Norovirus is primarily linked to contaminated water or food that has been handled by an infected person, rather than specifically tied to dairy products as Listeria is. Understanding these pathogen associations helps in implementing effective food safety measures within the food industry.