Which statement about Listeria monocytogenes in refrigerated dairy products is true?

• A. Listeria cannot grow in refrigerated dairy products.
• B. Listeria grows only at room temperature.
• C. Listeria monocytogenes can grow at refrigeration temperatures, posing a risk if post-pasteurization contamination occurs.
• D. Listeria is completely eliminated by pasteurization and cannot pose a risk later.

Answer: (C)

Listeria monocytogenes can grow at refrigeration temperatures, so it can multiply in refrigerated dairy products if it gets in after pasteurization. Refrigeration slows growth but doesn’t stop it, meaning that post-pasteurization contamination during processing, packaging, storage, or handling can allow the organism to increase to levels that pose a risk. Pasteurization kills Listeria in milk, but it does not protect against contamination that occurs after that step, which is why this statement is the true one. The other ideas—that it cannot grow in the fridge, or that it grows only at room temperature, or that pasteurization entirely eliminates the risk—don’t reflect how Listeria behaves in cold environments and the possibility of post-pasteurization contamination.