PRRSV经典毒株、高致病毒株、类NADC30毒株及类NADC34毒株鉴别RT-PCR检测方法的建立及应用OA北大核心CSTPCD

In order to improve the ability of the rapid differential diagnosis of different epidem-ic strains of porcine reproductive and respiratory syndrome virus(PRRSV),the Nsp2 nucleotide sequences of the prevalent PRRSV strains in recent years were compared,and the RT-PCR method was established to identify the classical strain(C-PRRSV),the highly pathogenic strain(HP-PRRSV),the NADC30-like strain(NADC30-like)and the NADC34-like strain(NADC34-like).The results showed that the amplified fragment sizes of Nsp2 genes of C-PRRSV,HP-PRRSV,NADC30-like and NADC34-like strains were 1 072 bp,982 bp,679 bp and 772 bp respectively,and the detection limits were 4.70×10 copies/μL,3.34 × 102 copies/μL,8.57×10 copies/μL,5.71 × 102 copies/μL respectively.No specific bands were amplified in other swine diseases,and the target fragment could be amplified uniformly and consistently in 3 replicates.27 samples were positive in 83 clinical tissue samples,including 7 NADC30-like positive samples and 20 NADC34-like positive samples,and the coincidence rate with GP5 gene results was 97.6％.The above re-suits indicated that the RT-PCR method for PRRSV identification established in this study possess good specificity,sensitivity and repeatability,and could be used for rapid identification and epidemio-logical investigation of C-PRRSV,HP-PRRSV,NADC30-like and NADC34-like strains.