ABSTRACT
Foot-and-mouth disease [FMD] is one of the most important virus disease in farm animals. Types O, A and Asial FMD virus have been endemic in Iran. In this study, samples from suspected livestock were analyzed by RT-PCR experiment. The number of 702 nucleotides determined at 1D- 2B region of type A strain isolated from Khorasan Razavi province sequenced and compared with that of other reported isolates type A from Iran and neighboring countries. The results show that field isolated type A has about 89% similarity with other reported isolates type A from Iran and neighboring countries. Furthermore, this virus shows the most similarity with A/IRN/1/87[Samuel. Phylogenitic analysis revealed that virus was closely related to A22-Iraq/99 and A/IRN/iso/105 that rest in the same lineage. The data showed high similarity between type A viruses involved in the Khorasan Razavi province and A/IRN/87v [vaccine strain]; so that it can be concluded that the vaccine can produce prophylactic antibody against this virus