We have analysed the ability to infect @entity1707 of two @entity4021 virus (FMDV) variants isolated at low frequencies from virus populations (quasispecies) generated in @entity1707 on infection with a parental virus, C-S8c1. A monoclonal antibody-resistant mutant (MARM21), and a variant isolated at early times post-infection (S- @entity54060 ), each exhibiting a unique @entity535 substitution in VP1, were able to cause disease in @entity1707 , both by direct inoculation or by contact transmission. The symptoms developed were similar to those produced by C-S8c1 or the related virus C-S15c1. The VP1 sequence of viral RNA directly recovered from lesions of infected animals confirmed the stability of the variant genotypes. @entity1707 infected with S- @entity54060 consistently showed an advance of 12 to 24 h in the emergence of fever and lesions when compared to animals infected with C-S8c1 or the remaining variants, an observation consistent with its early isolation. The ability of FMDV variants to compete in vivo with C-S8c1 was investigated in @entity325 experiments. Analysis of the proportion of each of the competitors in lesions of co-infected @entity1707 revealed that none of the variants was completely overgrown by the parent. However, @entity325 with C-S8c1 and MARM21 resulted in lesions in which C-S8c1 was predominant, indicating a selective disadvantage of this variant in @entity1707 . In contrast, lesions from @entity1707 co-infected with C-S8c1 and S- @entity54060 contained similar proportions of the two viruses. These results document fitness variations in vivo among components of the mutant spectrum of FMDV quasispecies.

In vivo analysis of the stability and fitness of variants recovered from XXXX virus quasispecies.

@entity1707 :: ('9823', 'Species') :: ['pigs', 'Pigs', 'swine'] @entity4021 :: ('MESH:D005536', 'Disease') :: ['foot-and-mouth disease'] @entity535 :: ('CHEBI:33704', 'Chemical') :: ['amino acid'] @entity54060 :: ('MESH:C013068|MESH:C019017', 'Chemical') :: ['3T1'] @entity325 :: ('MESH:D060085', 'Disease') :: ['co-infection']
@entity4021 :: (MESH:D005536,Disease) :: ['foot-and-mouth disease']
