猪繁殖与呼吸综合征病毒GD3株的分离鉴定及其分子特征

Isolation and characterization of PRRSV GD3 strain isolated in China

2005年从广东发病猪场采集的猪繁殖与呼吸综合征疑似病料中,分离到1株猪繁殖与呼吸综合征病毒(PRRSV),命名为GD3株。采用RT-PCR、IFA对分离毒株进行鉴定,并在Marc-145细胞上完成了病毒的增殖和理化性质的鉴定。应用RT-PCR方法扩增出GD3株的6条基因大片段,扩增产物克隆于pMD18-T载体鉴定后测序,同时应用RACE技术对GD3株的5'末端进行扩增和测序。结果表明GD3株基因组全长15425nt,包含个9开放阅读框,5'UTR长189nt,3'UTR长150nt。序列分析结果表明,GD3株在分子遗传演化上介于PRRSV变异毒株(HuN4株、JXA1株)和CH-1a之间,与HuN4和JXA1之间的相似性为97.1%和97.2%;与CH-1a的核苷酸相似性为94.9%。

The PRRSV GD3 strain was isolated in Guangdong province in 2005. It was identified by RT-PCR, and IFA test. The physico-chemical property of GD3 was tested on Marc-145. Six gene fragments of GD3 were amplified by RT-PCR and cloned into pMD18-T vector for sequencing. 5＇ ends was obtained by 5-Full RACE Core Set. The results showed that the complete genome of GD3 strain was 15 425 nt, containing nine open reading frames（ORFs） with 189 nt in the 5＇UTR and 150 nt in the 3＇UTR. The phylogenetic trees revealed the GD3 strain was a intergrade virus strain evoluated from classical PRRV CH-1a strain to the PRRSV JXA1 and HUN4 mutant strains indicated by 97.1%, and 97.2 % nucleotide homology with JXA1 and HuN4 strain, 94.9 % nucleotide homology with CH-1a strain.