Why shouldn't you mix cooked and raw foods?

Cross-contamination occurs when harmful bacteria from raw food spreads to cooked food. If you eat cooked food that has been cross-contaminated, you can get food poisoning. Some raw foods, such as raw meat, poultry, seafood, and eggs, can contain harmful bacteria such as Salmonella, Campylobacter, and E. coli. Cooking kills these bacteria, but if they are allowed to come into contact with cooked food, they can spread to the cooked food and make it unsafe to eat.