摘要
【目的】了解广东省某猪群中猪圆环病毒2型(Porcine circovirus type 2,PCV2)流行毒株的遗传进化情况,丰富PCV2分子流行病学数据,为当地PCV2疫苗候选株的选用和研发提供参考。【方法】使用qPCR方法对疑似PCV2的样品进行检测,发现1株具有高病毒载量的PCV2毒株,命名为GD222858。通过PCR方法进行全基因组分子克隆及遗传进化分析。使用MegAlign软件将该毒株ORF1、ORF2基因编码的氨基酸序列与PCV2同亚型参考毒株进行比对,分析氨基酸序列的相似性;采用DNAStar预测该毒株的Cap蛋白二级结构及B细胞表位,并与4株疫苗株DBN-SX07-2(HM641752)、LG(HM038034)、SH(HM038027)、ZJ(AY686764)的Cap蛋白抗原指数进行比对分析。【结果】GD222858毒株基因组长度为1767 bp。遗传进化分析表明该毒株属于PCV2d亚型。与国内外82株参考毒株的核苷酸相似性为91.4%~99.6%,与越南毒株Han8(GenBank登录号:JQ181600)的亲缘关系最近。在ORF1编码的Rep蛋白处发现多个特异性突变位点F70Y、F77L、W202R、N256S;ORF2编码的Cap蛋白相对保守。Protean预测Cap蛋白的氨基酸第5~18、24~25、39~41、48~49、57~65、99、101、112~114、139~140、145~150、162~165、175~181、188~189、205~211、227~232位置处均可能存在潜在的B细胞表位。GD222858毒株的Cap蛋白抗原指数与4株疫苗株均有差异,在氨基酸45~57、124~132、223~233位置处抗原指数明显高于4株疫苗株,且与疫苗株HM038034差异最大。【结论】GD222858毒株感染猪群的原因可能是Rep蛋白多个位点发生特异性突变及疫苗株选用不当所致。
【Objective】The study was carried out to understand the genetic evolution of Porcine Circovirus Type 2(PCV2) strains on a swine farm in Guangdong Province,and enrich molecular epidemiological data of PCV2,in order to provide reference for the selection and development of local PCV2 vaccine candidate strains.【Method】Samples suspected of PCV2infection were detected by using qPCR methods.A PCV2-positive isolate with a high viral load was found,named GD222858.Genome-wide molecular cloning and genetic evolution analysis were performed with PCR methods.MegAlign software was used to compare the amino acid sequences encoded by the ORF1 and ORF2 genes of the strain with the PCV2 isotype reference strain,and the similarity of the amino acid sequences was analyzed.The DNAStar was used to predicte the Cap protein secondary structure and B-cell epitope of this strain and compare it with the Cap protein antigen index of four vaccine strains DBN-SX07-2(HM641752),LG(HM038034),SH(HM038027) and ZJ(AY686764).【Result】Sequencing results showed that the genome length of GD222858 strain was 1 767 bp.The genetic evolution analysis indicated that the strain belonged to the PCV2d subtype.The nucleotide similarity with 82 reference strains at home and abroad ranged from 91.4% to 99.6%.It was closest to the Vietnamese strain Han8(GenBank accession No.:JQ181600).Multiple specific mutation sites F70Y,F77L,W202R and N256S were found at the Rep protein encoded by ORF1.The Cap protein encoded by ORF2 was relatively conserved.Protean predicted that the potential B cell epitopes presented at amino acid positions 5-18,24-25,39-41,48-49,57-65,99,101,112-114,139-140,145-150,162-165,175-181,188-189,205-211 and 227-232 of Cap proteins.The Cap protein antigen index of the GD222858 strain was different from that of the four vaccine strains,and the antigen index at the amino acids 45-57,124-132 and 223-233 was significantly higher than that of the other four vaccine strains,and the difference with the LG vaccine strain(HM038034) was greatest.�
作者
常鑫
蒋智勇
卞志标
徐民生
杨冬霞
杨傲冰
翟少伦
CHANG Xin;JIANG Zhiyong;BIAN Zhibiao;XU Minsheng;YANG Dongxia;YANG Aobing;ZHAI Shaolun(College of Animal Science and Technology,Zhongkai University of Agriculture and Engineering,Guangzhou 510305,China;Institute of Animal Health,Guangdong Academy of Agricultural Sciences/Guangdong Key Laboratory of Animal Disease Control and Research/Guangdong Scientific Observation and Experiment Station of Veterinary Drugs and Diagnostic Technology,Ministry of Agriculture and Rural Affairs,Guangzhou 510640,China;Guangdong Winsun Biopharmaceutical Co.,Ltd,Guangzhou 511356,China)
出处
《广东农业科学》
CAS
2024年第3期124-135,共12页
Guangdong Agricultural Sciences
基金
广州市重点研发计划项目(202206010192)
广东省科技计划项目(2021B1212050021)
广东省畜禽疫病防治研究重点实验室项目(2023B1212060040)。
