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ARS Home » Northeast Area » Orono, Maine » National Cold Water Marine Aquaculture Center » Research » Publications at this Location » Publication #418872
Research Project: Genetic Improvement of North American Atlantic Salmon and the Eastern Oyster for Aquaculture Production

Location: National Cold Water Marine Aquaculture Center

Title: Limited experimental susceptibility of post-smolt Atlantic salmon (Salmo salar) to an emergent strain of Vibrio anguillarum serotype-O3

Author
item Lifgren, Demitri
item TURNER, SARAH - University Of Maine
item Welch, Timothy - Tim
item BOUCHARD, DEBORAH - University Of Maine
item Polinski, Mark

Submitted to: Aquaculture Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/14/2024
Publication Date: 11/17/2024
Citation: Lifgren, D.L., Turner, S.M., Welch, T.J., Bouchard, D., Polinski, M.P. 2024. Limited experimental susceptibility of post-smolt Atlantic salmon (Salmo salar) to an emergent strain of Vibrio anguillarum serotype-O3. Aquaculture Journal. 2024; 4(4):283-292. https://doi.org/10.3390/aquacj4040021.
DOI: https://doi.org/10.3390/aquacj4040021

Interpretive Summary: An emergent strain of saltwater bacteria (Vibrio anguillarum serotype O3) has been attributed to die-offs of wild menhaden along the northeastern coast of the United states. The bacterial was also experimentally shown to kill young Atlantic salmon in freshwater by injection. This study explored the ability of this bacteria to kill Atlantic salmon juveniles in saltwater by either injection or cohabitation to identify risk potential to net-pen reared Atlantic salmon. We identified limited experimental evidence for low dose susceptibility or infection through natural (cohabitation) routes of transmission, suggesting the risk to Atlantic salmon by this bacteria is likely low.

Technical Abstract: An emergent strain of Vibrio anguillarum serotype O3 was attributed to a mass mortality event of Atlantic menhaden (Brevoortia tyrannus) along the New Jersey to Rhode Island coast in 2020 and 2021. V. anguillarum causes significant disease to Atlantic salmon (Salmo salar L.), and although disease has typically been associated with either O1 or O2 serotypes, preliminary evidence has shown the emergent SO3 strain to cause high mortality in pre-smolt Atlantic salmon by injection with >105 colony forming units (cfu). Here, we sought to identify the susceptibility of Atlantic salmon post-smolts to this emergent strain by both injection and cohabitation exposure to better understand transmission risk to and within cultured salmon. We identified that although mortality could be induced with high dose (>106 cfu) intraperitoneal injection of the emergent O3 serotype of V. anguillarum (cumulative mortality 40%), post-smolt Atlantic salmon were highly refractory to low dose (<106 cfu; cumulative mortality 3%) or cohabitation exposure (no mortality). A qPCR assay targeting the SO3 serotype was develop and analytically validated, revealing limited presence of bacterial DNA in spleen of low dose injected fish (2/36) and no detections in sampled cohabitants (0/70) across three time points during the 27-day challenge. These results suggest that although Atlantic salmon can succumb to high dose artificial infections with V. anguillarum S03, the risk of natural transmissibility and susceptibility of Atlantic salmon to this emergent V. anguillarum strain is anticipated to be low.