DAO 67:209-215 (2005)  -  doi:10.3354/dao067209

Pathogenic bacteria isolated from disease outbreaks in shellfish hatcheries. First description of Vibrio neptunius as an oyster pathogen

Susana Prado1,*, Jesús L. Romalde1, Jaime Montes2, Juan L. Barja1

1Departamento de Microbiología y Parasitología, Facultad de Biología, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain
2Centro de Investigacións Mariñas, Xunta de Galicia, Aptdo. 13, 36620 Vilanova de Arousa, Spain

ABSTRACT: Shellfish hatcheries are often affected by disease outbreaks. Three such episodes were investigated in different Galician hatcheries in order to establish the relationship between present microbiota and mortalities. Isolates were obtained from various parts of the hatcheries. Experimental tests for pathogenicity were carried out in microscale experiments using selected strains on Ostrea edulis larvae. The pathogenicity of 1 strain from each outbreak was demonstrated and shown to cause high mortalities (ranging from 98.5 to 100%) in 72 to 96 h after inoculation of larval cultures. All 3 strains belong to the genus Vibrio. One of the strains was identified as Vibrio neptunius and is the first description of this species as a molluscan pathogen. The other 2 strains showed low similarity with the Vibrio species analysed and may constitute new species within this genus.

KEY WORDS: Flat oyster · Vibrio · Vibrio neptunius · Pathogenicity test · Shellfish hatchery

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