Impact of Prophylactic Bacteriophage Addition on Survival of Crassostrea gigas Larvae

Aquaculture is a continuously growing industry, but rising problems are disease and antibiotic resistance. A common disease-causing pathogen in oyster aquaculture is Vibrio coralliilyticus (Vcor). Vcor infection of oyster larvae causes near 100% mortality within 48 hours, which is devastating to oys...

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Bibliographic Details
Main Author: Schmidt, Sarah
Other Authors: Madison, David, Langdon, Chris, Hatfield Marine Science Center
Format: Report
Language:English
unknown
Published: Oregon State University
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Online Access:https://ir.library.oregonstate.edu/concern/defaults/gb19ff594
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Summary:Aquaculture is a continuously growing industry, but rising problems are disease and antibiotic resistance. A common disease-causing pathogen in oyster aquaculture is Vibrio coralliilyticus (Vcor). Vcor infection of oyster larvae causes near 100% mortality within 48 hours, which is devastating to oyster hatcheries. One potential method of controlling Vcor outbreaks in hatcheries is with bacteriophage, a type of virus that infects bacteria. To determine if prophylactic addition of bacteriophage would remain active in Pacific oyster (Crassostrea gigas) larvae throughout the larval stage of development, a cocktail of 3 phages was added to larval culture buckets once at 3 days post-fertilization. A second treatment received the phage cocktail every 4 days, beginning at 3 days post-fertilization. A control treatment was included with no phage additions during larval culture. Samples of larvae were collected from the culture buckets and exposed to Vcor at 3, 7, 11, and 15 days post-fertilization using 24-well plates. Percent larval mortalities were compared among treatments and sampling days. We found that the single addition of phage did not significantly reduce the percent mortality compared to larvae grown without phage,but repeated additions of phage significantly decreased percent mortality of larvae exposed to Vcor. These results suggest repeated application of a phage cocktail to oyster larvae could reduce their susceptibility to infection by Vcor, potentially solving one of the major problems in aquaculture. Keywords: pacific oyster; Yaquina Bay, Oregon; Crassostrea gigas; Vibrio coralliilyticus; bacteriophages