Bacillus cereus emetic syndrome is due to which toxin and what is the typical food implicated?

• A. Cereulide toxin; reheated rice
• B. Enterotoxin; dairy products
• C. Alfa-toxin; undercooked beef
• D. Shiga-like toxin; leafy vegetables

Answer: (A)

Bacillus cereus emetic illness is driven by a preformed toxin in food, not by the bacteria after ingestion. The toxin, cereulide, is a heat-stable peptide that remains active even after cooking, and it triggers vomiting soon after ingestion by acting on the gut–brain emetic pathway. The classic scenario involves rice dishes that have been cooked and then kept at room temperature or reheated; as the rice sits, Bacillus cereus can produce cereulide, which survives heating and causes rapid emesis. So the best answer is cereulide toxin and reheated rice.