<unk>  is a gram negative bacterium with a curved-rod shape that causes<unk> in humans.<unk>  and other species of the genus<unk>  belong to the gamma subdivision of the Proteobacteria.  There are two major strains of<unk> , classic and El Tor, and numerous other serogroups.<unk>  was first isolated as the cause of<unk> by Italian anatomist Filippo Pacini in 1854, but his discovery was not widely known until Robert Koch, working independently thirty years later, publicized the knowledge and the means of fighting the disease.
Vibrio cholerae
Salmonella enterica
Salmonella
Shigella
Clostridium difficile
Salmonella enteritidis
Shigella dysenteriae
Yersinia