PEDV地方流行毒株S1基因的遗传变异分析及HLJ-2012株免疫原性检测

Genetic variation analysis of S1 genes of PEDV endemic strains and immunogenicity detection of HLJ- 2012 strain

为探讨猪流行性腹泻（Porcine epidemic diarrhea，PED）再次爆发原因，对现阶段黑龙江省和内蒙古自治区的10株猪流行性腹泻病毒（Porcine epidemic diarrhea virus，PEDV）流行毒株S1基因进行扩增、克隆和序列测定，通过序列比对分析其遗传演化特点。选择其中一株毒株进行中和试验，对其免疫原性做初步分析。结果表明，10株PEDV的S1基因与参考毒株相比，核苷酸同源性为86.8%-99.7%；且S1基因均存在点突变、碱基插入及缺失的情况；构建的系统发育树表明PEDV毒株在S1基因水平上共分为两个群，本试验中的10株均处在G1群，与2011-2012年3株其他地区毒株CH/SDQD/2011、CH/HBQHD/2011和HuN亲缘关系较近，而与G2群中的经典毒株CV777及我国以往报道过的LJB/03等亲缘关系较远；通过中和试验，判断出新发毒株HLJ-2012对传统毒株LJB/03具有一定的中和效应，中和效价为1？？53.83。

To explore the possible reason of the PEDV re-outbreaks, the genetic variation characteristic of PEDV S1 genes was analyzed, S1 genes of 10 PEDV strains collected from Heilong-jiang Province and Inner Mongolia Autonomous Region were amplified, cloned, sequenced and compared. To make a preliminary immunogenicity analysis, one of the PEDV strains was chosen to perform the neutralization test. It shows that the S1 gene nucleotide homologies of 10 PEDV strains is 86.8%-99.7%compared with the reference ones;and point mutations, insertion, deletion are all existed in S1 genes of the 10 PEDV strains. Phylogenetic tree showed that PEDV S1 genes are divided into two groups on the gene level, 10 isolates in this study are all at G1, and have a closely relationship with CH/SDQD/2011, CH/HBQHD/2011 and HuN. While they have a far relationship with classic CV777 and Chinese previous isolates LJB/03 etc. By neutralization test, the newborn strain HLJ-2012 has a neut-ralizing effect on traditional strain LJB/03, and the neutralization titer was 1？？53.83.