A day-care center decided tp prepare stir-fried rice to serve for lunch one day. The rice was cooked to the right temperature at 1:00 p.m. It was then covered and placed on a countertop, where it was allowed to cool at room temperature. At 6:00 p.m., the cook placed the rice in the refrigerator. At 9:00 a.m. the following day, the rice was combined with the other ingredients of stir-fried rice and cooked to 165* F for at least 15 seconds.The cook covered the rice and left it on the stove until noon when she reheated it. Within an hour of eating the rice, several of the children complained that they were nauseous and began to vomit. What pathogen caused the illness and why?

Bacillus cereus is a bacteria associated with foodborne infection (which is what happened to the children exposed in the question). These bacteria usually grow on rice that has not been properly cooled or heated.

The poisonings caused by Bacillus cereus result from the ingestion of food contaminated with the microorganism and / or the enterotoxins it produced during its growth. The poisonings associated with this microorganism are usually of short duration and not severe. However, several sporadic outbreaks and cases have been reported.