Characteristics of a persistent infection in Madin-Darby canine kidney cells with influenza C virus.

Influenza C/Ann Arbor/1/50 was used to establish a persistent infection in Madin-Darby canine kidney cells. The persistent state has been stable for more than 4 years (over 66 passages), with infected cells differing from controls in morphology and growth characteristics. In addition, virus recovered from the media of persistent cultures (passage 58) differed from parental wild-type virus C/Ann Arbor/1/50 in (i) antigenicity by the hemagglutination-inhibition test; (ii) its ability to produce plaques in different host cells; (iii) hemagglutination of chicken erythrocytes at different temperatures; (iv) receptor-destroying enzyme activity, and (v) by sensitivity to hemagglutination inhibitors present in rat serum.