A salmonid cell line (TO) for production of infectious salmon anaemia virus (ISAV)

A new cell line designated TO which provides a high yield of infectious salmon anaemia virus (ISAV) has been established. The cells originate from head kidney leukocytes isolated from Atlantic salmon and grow well at 20 degreesC in EMEM with 5% CO2 and without CO, supplement in HMEM. The cells have at present been passed more than 150 times and no changes in morphology, growth or virus production have been observed. The virus infection results in cytopathic effects (CPE) within 9 d, and the virus titre obtained from centrifuged and filtrated cell lysates, measured as TCID50, was about 10(9.1) ml(-1). The virus isolated from lysates of infected cells by a sucrose gradient provided purified ISAV when examined by silver stained SDS-PAGE. Salmon injected with diluted virus supernatant showed mortalities, hematocrit values and clinical signs in accordance with infectious salmon anaemia.