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 sal mon anaemia virus (ISAV) has been established. The cells originate from hea d kidney leukocytes isolated from Atlantic salmon and grow well at 20 degre esC 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, gr owth or virus production have been observed. The virus infection results in cytopathic effects (CPE) within 9 d, and the virus titre obtained from cen trifuged 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 grad ient provided purified ISAV when examined by silver stained SDS-PAGE. Salmo n injected with diluted virus supernatant showed mortalities, hematocrit va lues and clinical signs in accordance with infectious salmon anaemia.