The Novel PRRSV Strain HBap4-2018 with a Unique Recombinant Pattern Is Highly Pathogenic to Piglets

• 作者: Pengfei Chen Xiangmei Tan Mengqin Lao Xia Wu Xiongwei Zhao Shuting Zhou Jiarong Yu Junrui Zhu Lingxue Yu Wu Tong Fei Gao Hai Yu Changlong Liu Yifeng Jiang Guangzhi Tong Yanjun Zhou
• 来源期刊: 中国病毒学
• 年，卷（期）: 2021,（6）
• 所属期刊栏目: RESEARCH ARTICLES
• 页码范围: 1611-1625
• 页数: 15页
• 语种: 英文

摘要

Currently,various porcine reproductive and respiratory syndrome virus (PRRSV) variants emerged worldwide with dif-ferent genetic characteristics and pathogenicity,increasing the difficulty of PRRS control.In this study,a PRRSV strain named HBap4-2018 was isolated from swine herds suffering severe respiratory disease with high morbidity in Hebei Province of China in 2018.The genome of HBap4-2018 is 15,003 nucleotides in length,and compared with NADC30-1ike PRRSV,nsp2 of HBap4-2018 has an additional continuous deletion of five amino acids.Phylogenetic analysis based on complete genome and ORF5 showed that HBap4-2018 belonged to lineage 8 of PRRSV-2,which was characterized by highly variable genome.However,HBap4-2018 was classified into lineage 1 based on phylogenetic analysis of nsp2,sharing higher amino acid homology (85.3％-85.5％) with NADC30-1ike PRRSV.Further analysis suggested that HBap4-2018 was a novel natural recombinant PRRSV with three recombinant fragments in the genome,of which highly pathogenic PRRSV (HP-PRRSV) served as the major parental strains,while NADC30-1ike PRRSV served as the minor parental strains.Five recombination break points were identified in nsp2,nsp3,nsp5,nsp9 and ORF6,respectively,presenting a novel recombinant pattern in the genome.Piglets inoculated with HBap4-2018 presented typical clinical signs with a mortality rate of 60％.High levels of viremia and obvious macroscopic and histopathological lesions in the lungs were observed,revealing the high pathogenicity of HBap4-2018 in piglets.