Of 38 isolates of Vibrio vulnificus examined, all avirulent strains produced only translucent colonies. All virulent strains, with the exception of biogroup 2 (eel pathogens), exhibited both opaque and translucent colonies. Isogenic morphotypes were examined for a variety of phenotypic and virulence traits. Only the ability to utilize transferrin-bound iron and the presence of a surface polysaccharide were found to correlate with colony opacity and virulence.

We report the existence of a bioluminescent strain of the human pathogen Vibrio vulnificus. The isolate was obtained from blood following a fatal wound infection and thus represents the first description of an infection caused by a luminescent bacterium.