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Bacillus cereus is a bacterium which on Gram staining and microscopy is a gram positive bacillus.
The organism is ubiquitous in soil and in the environment, and is commonly found in raw, dried, and processed food. B Cereus spores can survive boiling, germinate and multiply rapidly at room temperature. It produces a heat-stable enterotoxin that causes vomiting, and a heat-labile enterotoxin that causes diarrhoea.
B. cereus causes food-poisoning characterised in some cases by sudden onset of nausea and vomiting, and in other cases by abdominal pain and diarrhoea. Illness is generally short-lived (no more than 24 hours) and is seldom severe.
It is associated with eating re-heated rice (or, occasionally) pasta. The "incubation period" will appear short, because the gastroenteritis is toxin-mediated: 1-6 hours for syndrome of nausea, vomiting, and abdominal pain; 6-24 hours for syndrome of diarrhoea and abdominal pain.
Stool should be sent for culture. If the rice (or other suspect food) was eaten at a restaurant or produced by a commercial caterer, Public Health/Environmental Health may be interested in testing food samples at that establishment.
Supportive only - rehydration.
Good food handling/storage practices, especially in eating establishments and at events such as weddings.