DEVELOPMENT OF PCR PRIMERS FOR SPECIFIC AMPLIFICATION OF 2 DISTINCT REGIONS OF THE GENOMES OF SAN-MIGUEL SEA-LION AND VESICULAR EXANTHEMA OF SWINE VIRUSES

The San Miguel sea-lion viruses (SMSV) and vesicular exanthema of swin e viruses (VESV) are members of the calicivirus family and aetiologic agents of vesicular disease in susceptible hosts. These two virus grou ps have been shown by several serological methods to be closely relate d antigenically. To further examine their relatedness, two sets of non -degenerate oligonucleotide primers were designed for the specific amp lification of two distinct regions of the SMSV and VESV genomes using a reverse transcriptase-polymerase chain reaction (RT-PCR) protocol. T he sequence of the primers were based on the nucleotide sequence of SM SV serotypes 1 and 4. The RNAs from a number of SMSV serotypes and a s ingle VESV isolate were used as template in this study. These included SMSV serotypes 1, 2, 4, 5, 6, 7, 13 and 14 and VESV serotype A,. Also included in this study were Tillamook calicivirus (Bos-1 calicivirus, BCV) and a recently isolated skunk calicivirus (SCV). The first prime r set amplified a 357-bp fragment from the 2C-like or RNA-helicase-enc oding region (11 of 11 viruses) and the second set amplified a fragmen t from the RNA-dependent RNA polymerase region (520 bp, 9 of 11 viruse s). These primer sets did not amplify product from either feline calic ivirus or mink calicivirus. The results of this study demonstrate the genetic relatedness of SMSV and VESV and the potential usefulness of R T-PCR to detect and identify these viruses in diagnostic and routine s creening applications.