新发猪流行性腹泻病毒分子变异分析

Molecular variation analysis of new porcine epidemic diarrhea viruses

采用RT-PCR方法对5份疑似流行性腹泻病毒感染猪场采集的腹泻粪便样品和小肠组织样品进行扩增、克隆和测序，并利用DNAStar进行序列对比及进化分析。结果表明：5个PEDVS及ORF3基因核苷酸序列同源性为96．2％～99．6％，氨基酸同源性为86．3％～99．3％。与经典病毒株CV777相比，CH—GZH毒株在PEDVS基因3581～3583bp处存在3个核苷酸缺失；CH-ZJ毒株在ORF3基因245～293bp处缺失49个核苷酸。S及ORF3基因进化树分析结果表明，4株PEDV与中国毒株BJ．2011～1亲缘关系较近；CH-ZJ独立于其他中国病毒株独自构成一个群体，与其他病毒株有较大差异。

Five samples of diarrhea excrement and small intestine tissue from a pig farm suspicious- ly infected with the porcine epidemic diarrhea virus（PEDV）were amplified, cloned and sequenced by a RT-PCR method,and the sequence alignment and evolutionary analysis were made by using DNAStar. The results showed that the 5 PEDV S and ORF3 genes were 96.2% - 99.6% in nucleotide sequence homology and 86.3% -99.3% in amino acid sequence homology. Compared with a classical virus strain CV777,the CH-GZH strain had 3 nucleotides deletion between 3 581 -3 583 bp of the S gene, and the CH-ZJ deleted 49 nucleotides between 247 and 295 bp of the ORF3 gene. The phylogenetic tree analysis of the S and ORF3 genes showed that the 4 PEDV strains had a close genetic relationship with the Chinese strain BJ-2011-1 ,while the CH-ZJ was quite different from other virus strains and in- dependently formed a population.