Which of the following is the biological contaminant most often found in eggs?

Salmonella is recognized as the biological contaminant most often associated with eggs. This bacterium can be present in the intestines of healthy poultry and can contaminate eggs during the laying process. When an egg is formed, it can sometimes be contaminated with Salmonella if the hen is carrying the bacteria, either on the eggshell or within the egg itself.

Salmonella infection can lead to foodborne illness when undercooked or improperly handled eggs are consumed. This is why it is critical to store and cook eggs properly to reduce the risk of salmonellosis. Techniques such as refrigeration and cooking eggs until both the white and yolk are firm are essential preventive measures.

In contrast to Salmonella, while Listeria is commonly associated with dairy products and ready-to-eat meats, E. coli is primarily linked to undercooked beef or contaminated produce. Campylobacter is often found in poultry but is less directly associated with eggs compared to Salmonella. Thus, Salmonella's specific link to eggs makes it the correct answer in this context.