RT-PCR to identify replicative strands of RNA of ISAV

Description

Infectious salmon anemia (ISA) is caused by a virus and affects salmon culture in Atlantic Provinces since 1996. Among available diagnostic tests, RT-PCR is often used and detects viral RNA genome in tissue. ISA virus is producing different genomic strands during infection, some specifically needed for its replication, and undistinguishable by regular RT-PCR assays. Justified concerns exist regarding the validity of incorporating the results from RT-PCR into the process of determining ISAV status. Specifically, existing RT-PCR tests may not discriminate between viable virus capable of replication and non-viable virus remnants resulting from viral disintegration, neither between different RNA strands. Greater confidence in decision-making would be achieved with an RT-PCR result that provides information regarding the relative amount of viral RNA vs template RNA (the latter reflects the infectious potential of the virus).

The objectives of this project are to develop a sensitive RT-PCR assay which can be used to determine the viral load, or if possible, the replicative status of ISAV in tissue as determined by the relative amount of replicative strand RNA in a particular sample. Where possible, correlation of the amount of virus RNA with clinical and sub clinical infections in fish would be made.

Program Name

Aquaculture Collaborative Research and Development Program (ACRDP)

Year(s)

2001 - 2004

Ecoregion(s)

Atlantic: Gulf of Maine, Scotian Shelf

Principal Investigator(s)

Nellie Gagné
Email: Nellie-Gagne.Davidson@dfo-mpo.gc.ca