Premium
A strain of porcine deltacoronavirus: Genomic characterization, pathogenicity and its full‐length cDNA infectious clone
Author(s) -
Zhou Xinrong,
Zhou Lei,
Zhang Pingping,
Ge Xinna,
Guo Xin,
Han Jun,
Zhang Yongning,
Yang Hanchun
Publication year - 2021
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.13862
Subject(s) - biology , virology , viral shedding , virus , antibody , microbiology and biotechnology , coronavirus , pathology , medicine , covid-19 , immunology , disease , infectious disease (medical specialty)
As a novel enteropathogenic coronavirus, porcine deltacoronavirus (PDCoV) warrants further investigation. In this study, a Chinese PDCoV strain, designated CHN‐HN‐1601, was isolated from the faeces of a diarrhoeic piglet. After plaque purification, the genome was determined which shared 97.5%–99.5% nucleotide identities with 71 representative PDCoV strains available in the GenBank. The pathogenic properties of CHN‐HN‐1601 were evaluated using 5‐day‐old piglets. All inoculated piglets developed severe diarrhoea from 2 days post‐infection (dpi) onwards. To our surprise, two periods of diarrhoea starting from 2 to 7 dpi and from 13 to 19 dpi were observed in affected piglets during the experiment. Faecal viral shedding of the inoculated piglets was detected by real‐time RT‐PCR, with viral shedding peaked at 4 and 16 dpi, respectively. At necropsy at 5 dpi, the main gross lesions included transparent, thin‐walled and gas‐distended intestines containing yellow watery contents. Further histopathological examinations, including haematoxylin and eosin staining, immunohistochemistry and RNAscope in situ hybridization, revealed that the virus infection caused severe villous atrophy of the small intestines, with PDCoV antigen and RNA mainly distributed in the cytoplasm of the villous epithelial cells of jejunum and ileum in piglets. The dynamic production of PDCoV‐specific IgG and neutralizing antibodies in serum of the affected piglets was also assessed using a whole virus‐based ELISA and an immunofluorescence assay‐based neutralization test, respectively. Furthermore, a full‐length cDNA infectious clone of CHN‐HN‐1601 was constructed using a bacterial artificial chromosome system. The rescued virus exhibited in vitro growth and pathogenic properties similar to the parental virus. Taken together, our study not only enriches the information of PDCoV, but also provides a useful reverse genetics platform for further pathogenesis exploration of the virus.