Grouping of V. vulnificus strains based on the relationship between skin and liver CFU counts. The CLUSTER program of SAS was used to examine the skin and liver CFU counts of V. vulnificus strains. Strains with a cluster distance of less than 1.0 were considered a group. Group 1, □, very low level in skin, undetectable in liver; group 2, Δ, low level in skin and undetectable to low level in liver; group 3, ○, high level in skin and undetectable to low level in liver; group 4, ⋄, high level in skin and moderate to high level in liver; group 5, ×, very high level in skin and very high level in liver. vcgC genotype strain symbols are white; vcgE genotype strain symbols are gray.