Any of a group of aquatic, comma-shaped bacteria in the family Vibrionaceae.
Some species cause serious diseases in humans and other animals. They are gram-negative (see gram stain ), highly capable of movement (with one to three flagella at one end), and do not require oxygen. Their cells are curved rods, single or strung together in S-shapes or spirals. Two species are of significance to humans: one causes cholera , the other acute bacterial diarrhea.