Foot-and-mouth disease virus subtyping by sequencing VP1 genes.

In order to use nucleotide sequencing for foot-and-mouth disease virus (FMDV) diagnostic subtyping, it is necessary to shorten the time required for preparation of suitable templates. The time required for analysis was reduced by use of the viral RNA present in the total RNA extract of tissue from infected cattle as a template in the Sanger sequencing reaction. Results are now available within 3 days. The sequences determined encode capsid protein VP1 and therefore major neutralization epitopes. Such a sequence of FMDV O1Kaufbeuren, cultured in the animal, was compared with those of tissue-cultured viruses. They did not differ. It was concluded that a change of virus culture conditions does not necessarily account for antigenic variation.