Novel lineage 1 recombinants of porcine reproductive and respiratory syndrome virus isolated from vaccinated herds: genome sequences and cytokine production profiles.
Arch Virol
; 165(10): 2259-2277, 2020 Oct.
Article
em En
| MEDLINE
| ID: mdl-32699981
ABSTRACT
Porcine reproductive and respiratory syndrome virus (PRRSV) is a widely disseminated, macrophage-tropic arterivirus that exhibits profound genetic and pathogenic heterogeneity. The present study was conducted to determine the complete genome sequences of two novel Korean lineage 1 PRRSV-2 strains, KNU-1901 and KNU-1902, which were isolated from vaccinated pig farms experiencing unusually high morbidity and mortality. Both isolates contained notable discontinuous 423-nucleotide deletions (DELs) within the genes encoding nonstructural protein 2 (nsp2) and GP3 when compared with the prototype strain VR-2332. In particular, the nsp2 DEL viruses had unique quadripartite discontinuous DEL signatures (111-1-19-9) in nsp2; this is an expanded version of the tripartite 111-1-19 DEL previously identified in virulent lineage 1 PRRSV-2 strains. Phylogenetic analysis revealed that both novel nsp2 DEL viruses belong to the Korean clade (KOR C) of lineage 1 isolates based on ORF5 but cluster with lineage KOR A strains based on the nsp2 or complete genome sequence. Recombination detection analysis suggested that both novel isolates are recombinants and may have evolved via natural inter-lineage recombination between circulating KOR A and KOR C strains. Interestingly, compared with the prototype VR-2332 virus, the novel nsp2 DEL variants were less efficient at promoting the expression of immune response genes in porcine alveolar macrophage culture. Taken together, we conclude that KNU-1901 and KNU-1902 are recently evolved recombinant variants of the virulent lineage 1 family that caused the regional severe PRRS outbreaks.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Filogenia
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Citocinas
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Genoma Viral
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Proteínas não Estruturais Virais
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Vírus da Síndrome Respiratória e Reprodutiva Suína
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Síndrome Respiratória e Reprodutiva Suína
Limite:
Animals
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article