Rotavirus persistence in cell cultures: selection of resistant cells in the presence of foetal calf serum.

The Lincoln strain of bovine rotavirus, cytocidal for bovine AU-BEK cells, can establish in the same cell cultures in the presence of foetal calf serum (FCS) a persistent infection that depends on selection of highly resistant cells. In fact, after the induction of the carrier state only a small fraction of the cell population was infected. The parental and the carried viruses are not demonstrably different, the cultures are resistant to superinfection by the homologous virus, the cultures can be cured by antiviral serum in the medium and uninfected resistant cell clones can be selected. The presence of FCS was essential during induction and maintenance of persistence. Its effects appear to be exerted not on the control of virus replication in fully sensitive cells but on the proliferation and selection of the resistant cells.