What is the toxin and typical food vehicle associated with the diarrheal form of Bacillus cereus?

• A. Emetic toxin; associated with popcorn
• B. A diarrheal enterotoxin; disseminates after ingestion of reheated rice and pasta
• C. Shiga-like toxin; undercooked beef
• D. Neurotoxin; seafood

Answer: (B)

Diarrheal illness from Bacillus cereus comes from a protein enterotoxin produced in the gut after ingestion of contaminated food. The typical offender is cooked starches like rice and pasta that have been left at warm temperatures and then eaten after reheating; symptoms usually start about 6–24 hours later. This is different from the emetic form, which is caused by a preformed, heat-stable toxin and tends to cause rapid vomiting, often linked to foods like popcorn or fried rice. The other options mix the toxin type with food vehicles that fit different problems (emetic toxin with popcorn; Shiga-like toxin with undercooked beef; neurotoxin with seafood), so they don’t describe the diarrheal Bacillus cereus syndrome.