Vibrio is a genus of gram-negative bacteria possessing a curved rod shape, several species of which can cause foodborne infection, usually associated with eating undercooked seafood. Typically found in saltwater, "Vibrio" are facultative anaerobes that test positive for oxidase and do not form spores. All members of the genus are motile and have polar flagella with sheaths. Recent phylogenies have been constructed based on a suite of genes (multi-locus sequence analysis).