2016年我国3株欧洲型猪繁殖与呼吸综合征病毒的分离鉴定及其全基因组特征分析

摘要

Three isolates of genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV),named ZD1,WK14 and WG9,were detected from nine provinces or cities in 2016 in china.Their complete genomes were sequenced and analyzed.Phylogenetic analysis showed that three PRRSVs located in subgenotype I of genotype 1.Compared with LV and VR2332 representative strains of genotype 1 and 2,the nucleotide similarity of these isolatesis were 88.7％-88.9％ and 60.7％-60.8％.respectively.The deduced amino acid alignment of ORF3 and ORF4 suggested that the ORF3 of ZD1 had 26aa premature termination;Both WK14 and WG9 strains had 1aa deletion at position aa245 of ORF3;Three PRRSVs shared 1 aa deletion at position aa66 of ORF4.In addition,WK14 is a mosaic virus between BJEU06-1as parental strain and NVDC-FJ providing partial gene fragment at positions 931-3,379,whereas ZD1 and WG9 were not.In the present study,there are some new characteristics such as recombination and deletion in the genome of genotype 1 PRRSV.Therefore,it's necessary to monitor genotype 1 PRRSV continuously and investigate their biological charateristics further.%2016年,本实验室共检测到3株基因1型(欧洲型)猪繁殖与呼吸综合征病毒(PRRSV),分别命名为ZD1株、WK14株和WG9株,本研究对3株PRRSV进行了全基因组序列分析.遗传演化分析显示,3株PRRSV均属于基因1型Ⅰ亚型,与基因1型代表株LV的核苷酸同源性为88.7 ％～88.9％,与基因2型代表株VR2332的核苷酸同源性为60.7％～60.8％.ORF3与ORF4推导氨基酸序列比对结果显示,ZD1株的ORF3提前26个氨基酸(aa)终止,这是首次报道基因1型PRRSV编码的结构蛋白存在提前终止现象,WK14株与WG9株在ORF3的245位存在1个氨基酸的缺失;3株PRRSV在ORF4的66位皆存在1个氨基酸的缺失.Simplot生物学重组软件分析表明,WK14株为重组病毒,供体病毒株为BJEU06-1,提供重组片段的病毒株为NVDC-FJ,重组位置位于第931～3 379位碱基处.ZD1株和WG9株未发现重组现象.本研究发现我国欧洲型PRRSV基因组在缺失、重组等方面正发生一些新的变化,有必要对该类病毒进行持续监测和深入研究.