Distribution of Vibrio parahaemolyticus ATCC17802 in tissues of adult Pacific oysters (Crassostrea gigas) under starvation conditions

Abstract

The Pacific oyster (Crassostrea gigas) is an economically pivotal aquaculture species that is cultured all over the world. To explore the risk of key pathogenic microorganisms in vivo, the distribution and likelihood of Vibrio parahaemolyticus colonizing four different oyster tissues were studied. Adult oysters were infected with a constant concentration (7 log colony-forming units (CFU)/ml) of V. parahaemolyticus after a one-week period of starvation at 21 °C. Following a 102-h period of experimental challenge, the distribution of V. parahaemolyticus in the four tissues examined (mantle, digestive glands, adductor muscles, and gills) was significantly different (p < .05). Vibrio parahaemolyticus showed a higher preference for the mantle and digestive glands than for the gills and adductor muscles. Vibrio parahaemolyticus survived in the mantle and digestive glands at approximately 4–5 log CFU/g and 5 log CFU/g, respectively. Changes in the morphology of the mantle tissue indicated that adult Pacific oysters were more susceptible to vibriosis under starvation conditions and demonstrated that mantle tissue was an important target of infection.