Minimum number of cells required for reconstitution of a foot-and-mouth disease virus-carrier cell culture.

A serial cell plating experiment has been designed to determine the minimum number of cells, isolated from a culture persistently infected with a virus, required to reconstruct the carrier state. For cell line C1-BHK-Rc1, consisting of BHK-21 cells persistently infected with foot-and-mouth disease virus type C (isolate C-S8c1), more than 10(3) cells derived from one monolayer were needed to reinitiate a stable, FMDV-producing carrier culture. Thus, the FMDV-BHK-21 cell system cannot be explained merely as a sum of its individual components. The results suggest, instead, that the behaviour of C1-BHK-Rc1 cultures is the result of complex interactions acting at the population level. Implications for viral persistence are discussed.