中国新发L1A PRRSV变异株的出现与流行状况分析  

Analysis of the emergence and epidemic status of new L1A PRRSV variants in China

作　　者：许浒 龚帮俊 李超 孙琪 李宛生 赵静 郭镇洋 李金昊 张思钰 相丽润 彭金美[1] 王倩[1] 周国辉[1] 冷超粮[2] 汤艳东 赵鸿远 安同庆[1] 蔡雪辉[1] 张洪亮[1] 田志军[1] XU Hu;GONG Bang-jun;LI Chao;SUN Qi;LI Wan-sheng;ZHAO jing;GUO Zhen-yang;LI Jin-hao;ZHANG Si-yu;XIANG Li-run;PENG Jin-mei;WANG Qian;ZHOU Guo-hui;LENG Chao-liang;TANG Yan-dong;ZHAO Hong-yuan;AN Tong-qing;CAI Xue-hui;ZHANG Hong-liang;TIAN Zhi-jun(State Key Laboratory for Animal Disease Control and Prevention,Harbin Veterinary Research Institute,Chinese Academy of Agricultural Sciences,Harbin 150069,China;Nanyang Normal University,Nanyang 473061,China;School of Modern Agriculture and Biotechnology,Ankang University,Ankang 725000,China)

机构地区：[1]中国农业科学院哈尔滨兽医研究所动物疫病防控全国重点实验室,黑龙江哈尔滨150069 [2]南阳师范学院,河南南阳473061 [3]安康学院现代农业与生物科技学院,陕西安康725000

出　　处：《中国预防兽医学报》2023年第8期779-786,共8页Chinese Journal of Preventive Veterinary Medicine

基　　金：国家自然科学基金(32002315、32172890);黑龙江省自然科学基金(YQ2022C042);安康市农业科技攻关项目(AK2022-NY-12);河南省高等学校重点科研项目(22A230016);国家生猪技术创新中心(NCIP-XD/C09)。

摘　　要：2017年我国首次发现类NADC34 PRRSV,该类病毒属于L1A(Sublineage1.5)亚型。近年来,新发类NADC34 PRRSV在我国不断变异,已经成为危害我国养猪业重要的PRRSV亚型。为了确定新发类NADC34 PRRSV的流行特征,本研究从2021年~2023年37份新发类NADC34 PRRSV阳性病料样品中选择4份样品经PCR分段扩增PRRSV全基因组序列并测序,利用SeqMan软件拼接,获得了4株完整的PRRSV全基因组序列,相应的病毒分别命名为TZJ2165、TZJ2451、TZJ2756、WK621株。下载GenBank中所有中国类NADC34 PRRSV和美国L1C变异株的ORF5基因及NSP2基因序列,利用MEGA7.0构建上述PRRSV ORF5基因序列的遗传进化树,分析其遗传变异情况。利用Megalign软件分析各分支内ORF5基因序列的相似性,以及新发类NADC34 PRRSV NSP2氨基酸序列,分析其是否存在一致的氨基酸缺失特征。根据PRRSV ORF5基因的限制性片段多态性(RFLP)分类方法,对新发类NADC34 PRRSV的ORF5基因序列分类。利用Simplot软件分析新发类NADC34 PRRSV和L1C变异株全基因组序列中的重组事件。基于ORF5基因进化树结果显示,这4株新发类NADC34 PRRSV与之前分离的TZJ2007、BJ-20-06等12株PRRSV均属于L1A亚型,与早期类NADC34 PRRSV相比,这些病毒株形成了一个独立分支,将其命名为L1A变异株,且其ORF5基因序列的相似性≥93%。NSP2氨基酸序列比对分析发现,L1A变异株具有一致的131个氨基酸不连续缺失的分子特征。ORF5基因的RFLP模式分析结果显示,L1A变异株RFLP模式分为1-4-2、1-4-4、1-5-4、1-7-4和1-6-4,模式并不一致。重组分析结果显示,L1A变异株存在相似的重组模式,它们均是以NADC30株(类NADC30 PRRSV)为主要亲本,JXA1株(类HP-PRRSV)提供部分非结构蛋白基因区域、IA/2014/NADC34株(类NADC34 PRRSV)提供ORF2a~ORF6区域的重组病毒。目前L1A变异株已经在黑龙江、内蒙古、辽宁、北京、广西、江苏、四川、福建、山东、广东和山西等11个省份检出。通过�NADC34-like PRRSV belonging to the L1A(Sublineage1.5)was first detected in China in 2017.In recent years,the emerging NADC34-like PRRSV have been continuously mutated in China,which has become an important subtype of PRRSV that harms the domestic pig industry.In order to determine the epidemic characteristics of emerging NADC34-like PRRSV,this study selected 4 samples from 37 emerging NADC34-like PRRSV positive samples from 2021 to 2023,and the whole genome of PRRSV was amplified by PCR.After the whole genome was sequenced,it was spliced by SeqMan software.The complete genome sequences of 4 strains of PRRSV were obtained,and named as TZJ2165,TZJ2451,TZJ2756 and WK621.The ORF5 and NSP2 gene sequences of all Chinese NADC34-like PRRSV and American L1C variant strains were downloaded from GenBank database.MEGA7.0 software was used to construct the genetic evolution tree of the above PRRSV ORF5 gene sequences,and analyze their genetic variation.The similarity of ORF5 gene sequences in the clade was analyzed by Megalign software,and the amino acid sequence of the emerging NADC34-like PRRSV NSP2 gene was derived to analyze whether there were consistent amino acid deletion characteristics.The ORF5 gene sequence of NADC34 PRRSV was classified according to RFLP method of PRRSV ORF5 gene.The recombination events in the whole genome sequence of NADC34-like PRRSV and L1C variants were analyzed using Simplot software.The phylogenetic analysis based on ORF5 gene showed that the four newly isolated NADC34-like strains and 12 previously isolated PRRSV strains such as TZJ2007 and BJ20-06 all belonged to L1A subtype.In comparison with the early NADC34-like PRRSV,these 4 strains formed an independent branch,named as L1A variant,those of ORF5 gene sequence showed similarity more than 93%.NSP2 amino acid sequence analysis showed that L1A variant had consistent molecular characteristics of 131 amino acid discontinuous deletion.However,the RFLP pattern analysis results of ORF5 gene showed that the RFLP patterns of the L1A variant was di

关 键 词：L1A PRRSV变异株 类NADC30 PRRSV 类NADC34 PRRSV HP-PRRSV 重组 出现与流行 

分 类 号：S852.65[农业科学—基础兽医学]