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2011年以来,我国多个省份免疫过伪狂犬病疫苗的规模化猪场发生新生仔猪出现神经症状和死亡的现象,并已确定为猪伪狂犬病病毒(pseudorabies virus,PRV)变异株感染所引起。为探究现PRV流行株特性,2014年下半年以来,我们从免疫过伪狂犬疫苗却暴发伪狂犬病的猪场分离到3株伪狂犬病病毒(分别为XP,QJ,LY株),并对其gE、gB、gC全基因进行测序和序列分析,序列比对结果显示,3株PRV分离株与2012年后分离毒株有较高的同源性;进化树分析显示,3株PRV分离株的gE基因与2012年后分离毒株处在同一进化树分支上,而gB、gC则分别形成了独立的小分支,但仍处在同一较大分支上。我们对当地广泛使用的疫苗株HB-98和Bartha-K61活疫苗免疫血清与Ea,HNX株以及3株PRV分离株进行中和试验,结果显示,HB-98和Bartha-K61活疫苗免疫血清对早期分离株Ea株的中和能力高于HNX、XP、QJ、LY株,但在NX、XP、QJ、LY株之间无明显差异,表明3株PRV分离株的抗原性与2012年后分离毒株无明显差异,而与传统毒株Ea株的抗原性存在一定差异。
Since 2011, neurological symptoms and death of newborn piglets have occurred in large-scale pig farms in different provinces in China that have been vaccinated against pseudorabies virus and have been identified as being caused by the infection of a pseudorabies virus (PRV) variant strain. To explore the characteristics of current PRV strains, three strains of Pseudorabies virus (XP, QJ, and LY strains) were isolated from pigs immunized with pseudorabies vaccine and outbreak of pseudorabies since the second half of 2014, and their gE , GB, gC gene were sequenced and sequence analysis. Sequence alignment showed that the three PRV isolates had high homology with the isolates after 2012. The phylogenetic tree analysis showed that the gE The genes were on the same branch of phylogenetic tree as the post-2012 strain, whereas gB and gC formed separate small branches, respectively, but were still on the same larger branch. We conducted a neutralization test on live vaccine immunization strains HB-98 and Bartha-K61 widely used in the local area with Ea and HNX strains and three PRV isolates. The results showed that the live vaccine serums of HB-98 and Bartha-K61 The neutralization ability of early isolate Ea was higher than that of HNX, XP, QJ and LY strains, but there was no significant difference between NX, XP, QJ and LY strains, indicating that the antigenicity of the three strains of PRV isolates was separated from that after 2012 There was no significant difference between the strains and the antigenicity of the traditional strain Ea.