Infective dose of salmonella typhi -

Ans. is 'c' i.e., 103-106 bacilli [Ref: Ananthanarayan 9th/ep. 295 & 8th/e p. 293)o In human volunteer experiments, the infective dose was found to be I0M06 bacilli.Organism Infective doseo ETEC-106-1010oEIEC-108-1010o EHEC-10-100 (< 103)o Shigella-10-100o Campylobactor jejuni-104o Yersinia enterocolitica-1010-109o Vibrio-1010 (if source of infection is water) -10*-104 (if source of infection is food)