SBIR-STTR Award

Infectious Hematopoietic Necrosis (IHN) is a highly infectious rhabdoviral disease of important species of trout and salmon, both cultured commercially and as part of federal and state sport fisheries and enhancement programs. There are presently no proven or accepted methods for prevention or treatment of IHN or IHN virus (IHN V) carries. Under the intensive culture conditions of aquaculture, IHN V can cause significant losses at nearly all stages of salmonid production. Additionally, adult salmonids that carry ihnv pose threats of egg-associated transmission of virus and as a reservoir of infection virus that could contaminate susceptible juveniles. Successful vaccination against IHNV might significantly reduce mortality and other disease problems associated with viral infection. Vaccination by injection is significantly more effective at eliciting a protective response compared to immersion delivery in fish. This injection vaccination against IHNV could provide a solution to the IHNV problem by eliciting IHNV neutralizing antibodies that have already been shown to be protective. Three types of IHNV vaccines are currently under development including modified-live (attenuated) and killed viruses, and a sub-unit vaccine produced by recombinant DNA technology. Each vaccine will be evaluated after injection delivery in two year old rainbow trout for induction and kinetics of IHNV neutralizing antibodies at two immonogen concentrations.

Infectious hematopoeitic necrosis (IHN) is a highly contagious rhabdoviral disease of important species of trout and salmon. There are presently no proven or accepted methods for prevention or treatment of IHN. Under the intensive conditions of aquaculture, IHN virus (IHNV) causes significant losses at nearly all stages of production. The results of Phase I studies indicated that intraspecific variation for IHNV resistance exists in rainbow trout and steelhead. The results of molecular genetic studies indicated that sufficient genetic variation exists both within and between the two strains of Oncorhynchus mykiss to allow for identification of genetic markers associated with IHN resistance which would significantly reduce the time required to develop IHN resistant strains.The Phase II research will determine the linkage of molecular markers to quantitative trait loci (QTL) associated with resistance to IHN. Disease resistance has a high environmental component of variability in expression, making it difficult to not only study but also to breed for the trait. Finding a molecular marker that is linked to a QTL will permit more rapid gains in selection for improvement in IHN resistance by marker assisted selection. This approach has found widespread use in plant breeding for viral disease resistance.

Anticipated Results/Potential Commercial Applications of Research:
Success in Phase II of this project would provide a foundation for the development of IHNV resistant rainbow trout stocks that could minimize millions of dollars of annual losses in cultured salmonids. Research results from this project may also provide great insight into salmonid viral resistance mechanisms that could benefit aquaculture programs. Additionally, this technology could be applied to other commercially important species, such as sockeye and Atlantic salmon, that are impacted by IHN. For Phase III, Clear Spring Foods, Inc., is prepared to finish breeding for IHNV resistance and conduct a thorough examination of the market and opportunity for product profitability.