<prompt> Food poisoning 2 hours after intake of food:Salmonella typhiBacillus cereusStaphylococcus aureusClostridium  <response>: Ans. c Staphylococcus aureusRef: Microbiology by Ananthanarayan and Paniker 8th ed. 198, Harrisons 18th ed. Ch 128 Among the given options staph aureus has the shortest incubation period 1-6 hrs. Staphylococcus causes food poisoning by enterotoxin A, due to intake of milk or milk products. It is a preformed, heat stable enterotoxin, which stimulate the vagus nerve causing vomiting as main and first symptom. I.P. 6 hours Outbreaks following picnics where potato salad, mayonnaise, and cream pastries have been served offer classic examples of staphylococcal food poisoning. Bacillus cereus is an important cause of food poisoning, isolated from soil, vegetables, milk cereals, meat etc. It produces 2 types of food poisoning:Diarrhea type- main symptomEmetic type- main symptom Associated with wide range of food intake including meat, puddings etc. I.P. 8-16 hrs Occurs due to heat labile enterotoxin Associated with intake of Chinese fried rice I.P. 1-5 hrs Due to pre-formed, heat stable toxin Clostridium perfringens causes gastroenteritis after intake of infected meat or meat products. I.P. - 8-16 hours. Clostridium botulism causes food poisoning due to consumption of canned food. I.P. 1 to 3 days. 