山东省免疫猪场猪伪狂犬病病毒分离鉴定及gE毒力基因的序列分析

Sequence analysis of gE gene among pseudorabies virus strains isolated from Bartha-k61-vaccinated swine population of Shandong province in 2013 and 2014

为了解山东省使用Bartha-K61疫苗免疫猪场猪伪狂犬病(PR)流行的原因,本研究对2013和2014年采自山东省免疫猪场的PR疑似病料进行了猪伪狂犬病病毒(PRV)的分离鉴定,并对分离毒株的毒力基因gE进行了序列测定与分析。结果表明,共分离到12株PRV,TCID50介于10^(-7.1)/0.1mL与10^(-9.5)/0.1mL之间。12株PRV的核苷酸和氨基酸序列的同源性分别为99.9%~100.0%和99.7%~100.0%;与亚洲毒株的核苷酸和氨基酸序列的同源性均高于欧美毒株。gE基因的氨基酸进化树分析表明,包括本研究分离的12株PRV在内的所有42株亚洲毒株属于GⅠ型,所有欧美毒株属于GⅡ型。这2个基因型之间分别在第58,105,148,178,180,214,215,470,500,505,518,522,569位氨基酸存在明显差异,可作为鉴别PRV欧美毒株与亚洲毒株的遗传标志。

We have determined TCID50 and gE gene nucleotide sequences of 12 pseudorabies virus（PRV）strains isolated from Bartha-K61-vaccinated swine population of Shandong province in 2013 and 2014.The results demonstrated that TCID50 of the 12 strains were 10-（-7.1）/0.1 mL to 10-（-9.5）/0.1mL.Sequence analysis showed that the 12 strains shared nucleotide and amino acid identities of 99.9%-100.0% and 99.7%-100.0%,respectively.Compared with Asian strains,the 12 strains shared lower nucleotide and amino acid identities with Euramerican strains.Phylogenetic analysis of gE amino acid indicated that all the 52PRV（including 12 strains isolated in this study and 40 reference strains）were clustered into two genotypes：all the Asian strains belonged to genotypeⅠ（GⅠ）,and all the Euramerican strains belonged to genotypeⅡ（G Ⅱ）.Discrepancies can be seen between two genotypes of PRV at 13 amino acid sites of 58,105,148,178,180,214,215,470,500,505,518,522 and 569in gE gene.These discrepancies can be regarded as genetic marker to distinguish the two genotypes of PRV.