Establishment of Carrier-State Infection of a Feline Renal Cell Line with Feline Syncytial Virus.

Although feline syncytial virus (FSV) is normally highly cytopathogenic in Crandell feline kidney cells, a non-cytopathic persistent infection was established in the cells after cocultivation of the initially infected cells with uninfected cells 4 times. More than 90% of the persistently infected cells were positive for FSV antigen, and electron microscopy showed that the culture produced morphologically normal FSV. Virus from the carrier culture was infectious, however, the titer of the virus from the culture was lower than that from the cytocidally infected CRFK cells.