Isolation and characterization of sialodacryoadenitis virus (coronavirus) from rats by established cell line LBC.

The outbreak of sialoadenitis occurred in a laboratory rat colony and the causative agent was isolated from the affected salivary glands of diseased rats using the established cell line LBC. The isolate readily multiplied, producing clear cytopathic effects with syncytium formation, and it was identified virologically and serologically as rat sialodacryoadenitis virus. In attempts to isolate the virus by primary rat kidney (PRK) cells and suckling mice as well as LBC cells, the LBC cells showed higher susceptibility for the virus growth as compared with PRK cells or the brain of suckling mice. The isolation rate of virus was 100% (5/5) in LBC, 40% (2/5) in PRK cells and 60% (3/5) in suckling mice. After four passages in the LBC cells, the virus did not produce disease in adult rats, while the mouse brain-passaged virus did.