DAO prepress abstract  -  DOI: https://doi.org/10.3354/dao03209

Genotypic assessment of effectiveness of a dichotomous key to identify Vibrio coralliilyticus, a coral pathogen

Francisca Gleire R. Menezes, Wescley E. Barbosa, Lorrana S. Vasconcelos, Rafael S. Rocha, Rodrigo Maggioni, Oscarina V. Sousa*, Ernesto Hofer, Regine H. S. F. Vieira

*Email: oscarinavs@ufc.br

ABSTRACT: Vibrio coralliilyticus is a known pathogen to corals and larvae of bivalves. Its identification is made based on phenotypic and genotypic characters of isolated strains. To evaluate the efficiency of the phenotypic identification, twenty-one strains identified as V. coralliilyticus by dichotomous key proposed by Noguerola & Blanch (2008) were analyzed by qualitative PCR and sequencing of the 16S rDNA region. The results obtained by the behavioral test, amino acids usage, allow us to distinguish three A/L/O profiles: (1) A+/L–/O+; (2) A+/L+/O+; and (3) A–/L+/O+. In the genotypic tests, all strains tested positive with primers specific for the Vibrio genus. However, when primers were used for species identification, the results did not match those obtained with the dichotomous key chosen. The phenotypic characteristics taken into account to set apart V. coralliilyticus and other species were not proven to be efficient. More information about the morphological diversity of colonies and enzymatic activities should be considered in the formulation of phenotypic keys for V. coralliilyticus and related species.