<prompt> Minimum infective dose of shigella is :A. 1-1010-100103-106Same as enteric fever  <response>: Ans: B 10-100 It has been shown that 106 pathogenic vibrios administered to fasting normochlorhydric volunteers, without food or buffer, did not produce infection, while the same dose along with food or sodium bicarbonate caused dinical cholera in 80-100 of them- Ananthanarayan 9th307Shigella cause bacillary dysentery. Infection occurs by ingestion. The minimum infective dose is low- as few as 10-100 bacilli are capable of initiating the disease, probably because they survive gastric acidity better than other enterobacteria- Ananthanarayan 9th287Enteric feversalmonella: In human volunteer experiments, the ID 50infective dose was found to be about 103 to 106 bacilli - Ananthanarayan 9th295 