Generation of an infectious cDNA clone of an FMDV strain isolated from swine.

A full-length cDNA clone of a foot-and-mouth disease virus (FMDV) isolated from swine was assembled in, the plasmid vector pBluescript II SK+ downstream of a T7 promoter. RNA synthesized in vitro using T7 polymerase lead to the production of infectious particles upon transfection of BHK-21 cells, as shown by cytopathic effects. The rescued virus was also found to be highly pathogenic for mice by intradermal injection producing a fatal disease indistinguishable from that of wild-type virus. The availability of this cDNA clone will allow examination of the molecular mechanisms behind FMDV virulence and attenuation, which might in turn allow the production of second-generation, genetically engineered FMDV vaccines.