Bacillus cereus Infection



Bacillus cereus


B. cereus is a common aerobic sporing organism. Its spores are often found in cereals and other foods, some of which will survive cooking and germinate into bacilli, which under warm storage conditions in cooked foods, will multiply and produce toxin. A wide variety of foods has been associated with outbreaks, particularly cornflour sauce in Norway and fried rice in Britain and other countries. As with C. perfringens, long moist storage of warmed cooked food.

There is no serological typing scheme for B. Cereus: certain serotypes occur more commonly in outbreaks than others and there are two different patterns of symptoms. The outbreaks arising from rice typically have a short incubation period of 1-3 hours with sudden onset of acute vomiting and some diarrhoea: the symptoms resembling those of staphylococcal enterotoxin food poisoning. The other pattern resembles C. perfringens food poisoning with an incubation period of 9-18 hours and diarrhoea as the chief symptom. The toxin responsible for the vomiting syndrome, which is probably preformed when the organism grows in food, is extremely heat resistant; it is not destroyed after 1 hours at 121oC. Other aerobic spore-bearing organisms such as B. Subtilis have also been described as agents of food poisoning with similar characteristics to those caused by B. Cereus.