Occurrence of Vibrionaceae in natural and cultivated oyster populations in the Pacific northwest

Studies were done to assess the role of oysters from the Pacific Northwest as a potential source of . Oysters collected from natural and cultivated populations on the British Columbia Coast were opened using sterile instruments. The gills and oyster meat were each removed, and the meat was cut in half. The gills and the cut surface of the oyster meat were each cultured by inoculating them directly to the surface of agar plating media for the isolation of . Overall, 120 oysters were cultured, and 60 yielded . , , and were the most commonly isolated organisms. were most often recovered from oysters collected under warmwater conditions from natural stocks (83% positive), followed by oysters from the same sites collected under cold-water conditions (35% positive). Only 29% of oysters collected from cultivated commercial stocks under warm water conditions yielded , and no were isolated from oysters collected from these sites during periods when water temperatures were low. The results suggest that oysters are a significant source of potentially pathogenic in the Pacific Northwest. However, the risk of exposure to these bacteria can be reduced by consumption of cultivated oysters harvested under cold-water conditions.