Characterization and cross-protection of experimental infections with SeCoV and two PEDV variants.
Transbound Emerg Dis
; 69(6): 3225-3237, 2022 Nov.
Article
em En
| MEDLINE
| ID: mdl-35918058
ABSTRACT
The aim of this study was to characterize the infection of weaned pigs with swine enteric coronavirus (SeCoV) - a chimeric virus most likely originated from a recombination event between porcine epidemic diarrhoea virus (PEDV) and transmissible gastroenteritis virus, or its mutant porcine respiratory coronavirus - and two PEDV G1b variants, including a recently described recombinant PEDV-SeCoV (rPEDV-SeCoV), as well as to determine the degree of cross-protection achieved against the rPEDV-SeCoV. For this purpose, forty-eight 4-week-old weaned pigs were randomly allocated into four groups of 12 animals. Piglets within each group were primary inoculated with one of the investigated viral strains (B PEDV; C SeCoV and D rPEDV-SeCoV) or mock-inoculated (A), and exposed to rPEDV-SeCOV at day 20 post-infection; thus, group A was primary challenged (-/rPEDV-SeCoV), groups B and C were subjected to a heterologous re-challenge (PEDV/rPEDV-SeCoV and SeCoV/rPEDV-SeCoV, respectively), and group D to a homologous re-challenge (rPEDV-SeCoV/rPEDV-SeCoV), Clinical signs, viral shedding, microscopic lesions and specific humoral and cellular immune responses (IgG, IgA, neutralizing antibodies and IgA and IFN-γ-secreting cells) were monitored. After primo-infection, all three viral strains induced an undistinguishable mild-to-moderate clinical disease with diarrhoea as the main sign and villus shortening lesions in the small intestine. In homologous re-challenged pigs, no clinical signs or lesions were observed, and viral shedding was only detected in a single animal. This fact may be explained by the significant high level of rPEDV-SeCoV-specific neutralizing antibodies found in these pigs before the challenge. In contrast, prior exposure to a different PEDV G1b variant or SeCoV only provided partial cross-protection, allowing rPEDV-SeCoV replication and shedding in faeces.
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MEDLINE
Assunto principal:
Doenças dos Suínos
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Infecções por Coronavirus
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Coronaviridae
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Vírus da Diarreia Epidêmica Suína
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article