The Vibrio harveyi hemolysin gene (vhh), which encodes for a virulence factor involved in pathogenicity
to fish and shellfish species, may be targeted for species detection or strain differentiation.
Primers designed for this gene were used in detection studies of V. harveyi strains from
various hosts. One primer set among four tested, could amplify the expected gene fragment in
PCR using templates from all 11 V. harveyi strains studied. Detection of the presence of the hemolysin
gene could therefore serve as a suitable detection marker of Vibrio harveyi isolates potentially
pathogenic to fish and shrimps.