Salmonella typhi is the causative agent of typhoid fever. The infective does of S.typhi
Ans. is 'c' i.e., 102-105 bacilli In human volunteer experiments, the infective dose was found to be 103-106 bacilli. Organism Infective dose . ETEC . EIEC . EHEC . Shigella . Campylobactor jejuni . Yersinia enterocolitica . Vibrio 106-101deg 108-10m 10-100( 104 108-109 1010 (if source of infection is water) 102-104 (if source of infection is food)
One bacillus
108-1010 bacilli
102-105 bacilli
1-10 bacilli