Which of the following pathogens is commonly linked to seafood such as raw oysters?

• A. Norovirus
• B. Vibrio
• C. Listeria monocytogenes
• D. Shigella

Answer: (B)

Raw oysters are a classic vehicle for Vibrio bacteria. Oysters filter large amounts of seawater, which concentrates bacteria present in warm coastal waters. When consumed raw, Vibrio parahaemolyticus and Vibrio vulnificus can cause illness ranging from gastroenteritis to, in more severe cases (especially with Vibrio vulnificus), bloodstream infections—more likely in people with liver disease or weakened immunity. This direct link between raw oysters and Vibrio makes this pathogen the best fit for a seafood-associated infection. Norovirus is also common in shellfish, but the hallmark bacterial association most people learn for raw oysters is Vibrio. Listeria monocytogenes and Shigella are linked to other food types or routes and are not as specifically tied to raw oysters.