Establishment and Application of a General RT-PCR Assay for Detection of BVDV Type 1 and 2
In order to establish a general RT-PCR assay to rapidly detect bovine viral virus(BVDV)type 1 and 2,the general primer was designed based on 5'UTR sequences of BVDV type 1 and 2 by Primer 6.0 software according to the analysis of complete gene sequence of 64 strains of BVDV type 1and 2 and one strain of classical swine fever virus(CSFV)registered in GenBank,and the target fragment was amplified,then the specificity,sensitivity and reproducibility of the RT-PCR method were evaluated,and the clinical samples were tested. The results showed that the amplified target fragment was about 302 bp;the detection limt of the method was 2.09×102 copies/μL,with no nonspecific amplification but good reproducibility. 13 nasal swabs and 9 bovine serum samples collected from an infected farm in Shandong Province were detected by the established method,it was found that 8 nasal swabs and 8 sera were positive against BVDV,then 4 of the positive samples were randomly selected to carry out virus gene sequencing and comparison,it was found that virus of 3 samples could be identified as BVDV type 1,and the other 1 sample still needed further analysis. In conclusion,specific detection of nucleic acids of BVDV 1 and 2 could be realized by the RT-PCR assay established in the study,which could also be used in epidemiological investigation of BVDV.