A patient present with vomiting he had eaten rice 6 hour before. The most probable cause is:

Ans. (a) Bacillus cereus This is a characteristic presentation of B.cereus food poisoning (emetic type). Bacillus cereus food poisoning Produces two type of food poisoning: a. Emetic type:- It is associated with contaminated frid rice; the organism is common in uncooked rice, and its heat-resistant spores survive boiling. It is mediated by staphylococcal type of enterotoxin. b. Diarrheal type:- Mediated by enterotoxin resembling E. coli. IP of diarrheal type is more in comparison to emetic type Diagnosis: The presence of B cereus in patient's stool is not sufficient to make a diagnosis of B cereus disease, since the bacteria may be seen in normal stool specimens; a concentration of 105 bacteria or more per gram of food is considered diagnostic.