“Development of New Vaccines Against T. finnmarkense in Salmon in Norway (7174)”

Development of New Vaccines Against T. finnmarkense in Salmon in Norway

Tenacibaculosis is a disease that causes skin ulcers and mouth erosions in Atlantic salmon. This disease, caused by members of the relatively newly discovered bacterial genus Tenacibaculum, has gained increasing attention as a disease agent over the past 10–15 years. Today, it is known that Tenacibaculum spp., along with other “wound bacteria,” contribute significantly to mortality, reduced welfare, and disease reported in the Norwegian salmon industry. Tenacibaculum finnmarkense genomovar finnmarkense is the dominant etiologic agent in non-classical winter ulcers.

In this project we tested various combinations of water-based immersion vaccines (dip vaccines) and oil-based intraperitoneal vaccines (IP vaccines) against T. finnmarkense before performing a challenge study to investigate the efficacy of administered vaccines. Specific IgM response against T. Finnmarkense in serum from the vaccinated fish was investigated by ELISA.

The results demonstrated a specific IgM response against T. finnmarkense in all IP vaccinated fish. Significant differences in mortality were observed between unvaccinated control fish and vaccinated fish. Immersion vaccination in combination with IP vaccination gave no additional antibody response or additional protection compared to IP vaccinated fish alone. However, in two of three tanks in the second challenge, double immersion with IP vaccination gave additional protection compared to only one immersion with IP vaccination. In the ongoing work we will investigate immune responses in, skin, gills, thymus, nose cavity and intestine in addition to kidney and spleen to determine how immersion vaccination affect the mucosal immunity.

Our result demonstrates protection against T. finnmarkense in an experimental challenge study and our trial vaccine may become the first vaccine that can effectively assist the salmon aquaculture industry in Norway in the combat against tenacibaculosis.

1. SETERNES, TORE, UNIVERSITY OF TROMSØ, Presenter
2. Mechlaoui, Marwa, University of Tromsø, Author
3. Erikstad, Helge-Andre, Vaxxinova Norway AS, Author
4. Haganes, Tone, Vaxxinova Norway AS, Author
5. Isdal, Eivind, Vaxxinova Norway AS, Author
6. Småge, Sverre, Cermaq AS, Author
7. Dalmo, Roy A., University of Tromsø, Author