Primary diagnosis of foot-and-mouth disease by reverse transcription polymerase chain reaction

Universal and serotype-specific primer sets were used in simple reverse tra nscription polymerase chain reaction (RT-PCR) assays on field samples of ep ithelium and vesicular fluid to determine their suitability for primary dia gnosis of all seven serotypes of foot-and-mouth disease (FMD). The specific ity of reactions was confirmed by using other vesicular disease viruses, na mely: swine vesicular disease virus, vesicular stomatitis virus and three v esiviruses. This resulted in the identification of a universal O/A/C/Asia 1 primer set (1F/1R) located in the 5' untranslated region (UTR) of the FMD virus genome for the successful detection of virus of these serotypes in cl inical samples although this primer set detected FMD virus of the SAT1/2/3 serotypes less efficiently. The 5' UTR universal primer set could be used f or the primary diagnosis of FMD in conjunction with the routine diagnostic methods of virus isolation in cell culture and ELISA, although a more favou rable reaction would be expected with FMD viruses of the O/A/C/Asia 1 group than with those of the SAT serotypes. The other examined universal and ser otype-specific primer sets, located principally in the P1 capsid-coding reg ion, were generally inferior to the 5' UTR universal primer set. It is envi saged that this evaluation of primers will lead to the development of alter native PCR strategies, for example nested PCR formats, with concomitant imp rovement in the speed of primary diagnosis of FMD which under present proce dures can be lengthy. (C) 2000 Published by Elsevier Science B.V.