Capsule: V. vulnificus has a capsule, made of polysaccharides, and is thought to protect against phagocytosis. The capsule also aids the bacteria in escaping opsonization. Different strains of the bacteria are capable of shifting through the unencapsulated and encapsulated forms. Mouse models have shown that the unencapsulated forms are avirulent. These same strains however, are shown to have a higher predisposition to shift to the virulent encapsulated form when taken up by oysters.
