Bacillus cereus

Bacillus cereus is a gram-positive, rod-shaped, spore-forming bacterium that has the ability to grow at a variety of temperatures and pH. Two types of illnesses arise as a result of consumption of food contaminated with B. cereus, emetic and diarrheal. The emetic syndrome is usually associated with starchy foods such as fried rice, pasta, etc. The illness is caused due to the ingestion of a preformed toxin in food (i.e., intoxication). The diarrheal syndrome, on the contrary, is associated with other types of foods such as milk, salads, and meat. Unlike the emetic syndrome, the diarrheal illness is caused by ingesting a large number of bacterial cells (i.e., toxico-infection). Healthy individuals usually recover from B. cereus illness within a day or two but patients who have other health issues may suffer serious complications. To control this bacterium in food, proper cooking and rapid cooling are required to prevent spores from germinating.