PROPAGATION OF INFECTIOUS SALMON ANEMIA (ISA) VIRUS IN CELL-CULTURE

A long-term cell line supporting growth of the infectious salmon anaem ia (ISA) virus has been established. The cell line (SHK-1) was develop ed from a culture of head kidney leucocytes from Atlantic salmon, and exhibited macrophage-like enzyme reactivities. By means of transmissio n experiments, ISA infectivity of cell culture medium could be demonst rated from day 5 after infection of SHK-1 cells with ISA-infective tis sue homogenate. ISA infectivity of cell culture medium increased follo wing repeated passages of virus. ISA-infected cell cultures develop cy topathic effects (CPE), making quantitation of virus possible. The dev elopment of CPE in ISA virus infected cells was inhibited by ammonium chloride, chloroquine and bafilomycin A, suggesting that infection of SHK-1 cells with ISA virus requires a low-pH step.