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The Emergence of H7N7 Highly Pathogenic Avian Influenza Virus from Low Pathogenicity Avian Influenza Virus Using an in ovo Embryo Culture Model.
- Source :
- Viruses (1999-4915); Sep2020, Vol. 12 Issue 9, p920, 1p
- Publication Year :
- 2020
-
Abstract
- Outbreaks of highly pathogenic avian influenza virus (HPAIV) often result in the infection of millions of poultry, causing up to 100% mortality. HPAIV has been shown to emerge from low pathogenicity avian influenza virus (LPAIV) in field outbreaks. Direct evidence for the emergence of H7N7 HPAIV from a LPAIV precursor with a rare di-basic cleavage site (DBCS) was identified in the UK in 2008. The DBCS contained an additional basic amino acid compared to commonly circulating LPAIVs that harbor a single-basic amino acid at the cleavage site (SBCS). Using reverse genetics, outbreak HPAIVs were rescued with a DBCS (H7N7<subscript>DB</subscript>), as seen in the LPAIV precursor or an SBCS representative of common H7 LPAIVs (H7N7<subscript>SB</subscript>). Passage of H7N7<subscript>DB</subscript> in chicken embryo tissues showed spontaneous evolution to a HPAIV. In contrast, deep sequencing of extracts from embryo tissues in which H7N7<subscript>SB</subscript> was serially passaged showed retention of the LPAIV genotype. Thus, in chicken embryos, an H7N7 virus containing a DBCS appears naturally unstable, enabling rapid evolution to HPAIV. Evaluation in embryo tissue presents a useful approach to study AIV evolution and allows a laboratory-based dissection of molecular mechanisms behind the emergence of HPAIV. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 19994915
- Volume :
- 12
- Issue :
- 9
- Database :
- Complementary Index
- Journal :
- Viruses (1999-4915)
- Publication Type :
- Academic Journal
- Accession number :
- 146538295
- Full Text :
- https://doi.org/10.3390/v12090920