Nam JH, Shim SM, Song EJ, Espano E, et al. Rapid virulence shift of an H5N2 avian influenza virus during a single passage in mice. Arch Virol 2017 Jun 29
Influenza A viruses must undergo adaptation to acquire virulence in new host species. In mouse models, host adaptation for virulence is generally performed through 5 to 20 lung-to-lung passages. However, highly pathogenic avian influenza viruses (e.g., H5N1 and H7N7 subtypes) have been observed to acquire virulence in mice after only a few in vivo passages. In this study, a low-pathogenic avian influenza H5N2 virus, A/Aquatic Bird/Korea/CN2/2009, which was a prevalent subtype in South Korea in 2009, was serially passaged in mice to evaluate its potential to become highly pathogenic. Unexpectedly, the virus became highly pathogenic in mice after a single lung-to-lung passage, resulting in 100% lethality with a mean death time (MDT) of 6.1 days postinfection (DPI). Moreover, the pathogenicity gradually increased after subsequent in vivo passages with an MDT of 5.2 and 4.2 DPI after the second and third passage, respectively. Our molecular analysis revealed that two amino acid changes in the polymerase complex (a glutamate-to-lysine substitution at position 627 of PB2 and a threonine-to-isoleucine substitution at position 97 of PA) were associated with the increased pathogenicity; the PB2 E627K mutation was responsible for the initial virulence conversion (0 to 100% lethality), while the PA T97I mutation acted as an accessory for the increased virulence.
See Also:
Latest articles in those days:
- [preprint] Emergence and interstate spread of highly pathogenic avian influenza A(H5N1) in dairy cattle 12 hours ago
- Modelling the transmission dynamics of H9N2 avian influenza viruses in a live bird market 12 hours ago
- CD8+ T-cell responses towards conserved influenza B virus epitopes across anatomical sites and age 3 days ago
- Surveillance for highly pathogenic avian influenza A (H5N1) in a raptor rehabilitation center-2022 3 days ago
- [preprint]Detection of hemagglutinin H5 influenza A virus sequence in municipal wastewater solids at wastewater treatment plants with increases in influenza A in spring, 2024 3 days ago
[Go Top] [Close Window]