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A natural recombinant PRRSV between HP ‐ PRRSV JXA 1‐like and NADC 30‐like strains
Author(s) -
Wang H.M.,
Liu Y.G.,
Tang Y.D.,
Liu T.X.,
Zheng L.L.,
Wang T.Y.,
Liu S.G.,
Wang G.,
Cai X.H.
Publication year - 2018
Publication title -
transboundary and emerging diseases
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.392
H-Index - 63
eISSN - 1865-1682
pISSN - 1865-1674
DOI - 10.1111/tbed.12852
Subject(s) - porcine reproductive and respiratory syndrome virus , recombinant dna , biology , virology , strain (injury) , genome , virus , recombinant virus , pathogenicity , gene , genetics , microbiology and biotechnology , anatomy
Summary Porcine reproductive and respiratory syndrome virus ( PRRSV ) is a major economically significant pathogen that has adversely affected China's swine industry. Currently, a novel type 2 PRRSV , called the NADC 30‐like strain, is epidemic in numerous provinces of China, and commercial vaccines provide limited protection for infected animals. The extensive recombination phenomenon among NADC 30‐like PRRSV s is identified as a unique molecular characteristic of the virus. However, our understanding of how recombination influences NADC 30‐like PRRSV s is largely inadequate. In this study, we analysed the genetic characteristics of a recombinant NADC 30‐like PRRSV ( SC ‐d) and examined its pathogenicity compared with a non‐recombinant NADC 30‐like PRRSV ( SD ‐A19) and a highly pathogenic PRRSV (HuN4). SC ‐d has three discontinuous deletions in nsp2, consistent with NADC 30 isolated from the United States in 2008. Furthermore, we identified four recombination breakpoints in the SC ‐d genome, which separated the SC ‐d genome into four regions (regions A, B, C and D). Regions A and C are closely related to the JXA 1‐like strain, one of the earliest Chinese HP ‐ PRRSV strains, and regions B and D are closely related to the NADC 30 strain. Moreover, SC ‐d inoculated piglets exhibited a persistent fever, moderate weight loss, mild thymus atrophy and obvious microscopic lung lesions. In summary, the recombinant NADC 30‐like PRRSV SC ‐d strain displayed a higher pathogenicity than the non‐recombinant NADC 30‐like PRRSV SD ‐A19 strain; however, the pathogenicity of the NADC 30‐like PRRSV SC ‐d was lower compared with the HP ‐ PRRSV HuN4 strain in piglets. Our findings demonstrate that recombination is responsible for the enormous genetic diversity and pathogenicity variance of the NADC 30‐like PRRSV in China. This study provides a theoretical basis for developing a more reasonable PRRSV control and prevention strategy.