FIG 7.

The stabilities of the ts&att phenotypes of the rC351G mutant during passaging in BHK-21 cells. (A) Twenty serial passages were performed in BHK-21 cells infected with rC351G. The 20th passage (p20) of rC351G was investigated for a ts phenotype in BHK-21 and IBRS-2 cells at different temperatures. The resulting virus was evaluated for titers by TCID₅₀ assay on BHK-21 cells. (B) The virulence of rC351G p20 was tested in suckling mice. The suckling mice were cervicodorsally inoculated with rC351G, rC351G p20, or FMDV(WT) diluted to different titers of TCID₅₀; animal deaths were scored for up to 7 days after inoculation, and survivors were euthanized (n = 6 to 9 for each group).