<unk>  is a rod shaped, flagellated, Gram-negative bacterium, and a member of the genus<unk> .<unk>  has an extraordinarily large number of serovars or strains—up to 2000 have been described.<unk>  Typhi is a serovar of<unk>  and the cause of the disease typhoid fever.
Salmonella enterica
Vibrio cholerae
Salmonella enteritidis
Campylobacter jejuni
Clostridium difficile
Shigella dysenteriae
Salmonella bongori
Shigella