<unk>  (Y.<unk> , a rod-shaped facultative anaerobe with bipolar staining (giving it a safety pin appearance) causes the infection in mammals and humans.  The bacteria maintain their existence in a cycle involving rodents and their fleas.  The genus<unk>  is gram-negative, bipolar staining coccobacilli, and, similarly to other Enterobacteriaceae, it has a fermentative metabolism. Y.<unk>  produces an antiphagocytic slime. The organism is motile when isolated, but becomes nonmotile in the mammalian host.
Yersinia pestis
Salmonella enterica
Rickettsia typhi
Vibrio cholerae
Salmonella bongori
Salmonella
Yersinia enterocolitica
Salmonella enteritidis