Which pathogen is linked with unpasteurized dairy products?

Listeria monocytogenes is specifically linked with unpasteurized dairy products due to its ability to thrive in refrigerated conditions where many other pathogens might not survive. This bacterium can cause severe illness, particularly in vulnerable populations such as pregnant women, newborns, the elderly, and individuals with weakened immune systems. Because unpasteurized dairy products do not undergo the heat treatment that kills harmful bacteria, they pose a significant risk of containing Listeria.

In contrast, while Salmonella, E. coli, and Bacillus cereus can also be associated with various foods, including dairy, they are more commonly linked to other sources. For example, Salmonella is frequently connected with raw meat and poultry, E. coli is often associated with undercooked ground beef or contaminated water, and Bacillus cereus is typically related to rice and pasta dishes. Thus, Listeria's strong association with unpasteurized dairy products makes it the correct answer in this context.