Genetic Analysis of Avian Influenza Viruses: Cocirculation of Avian Influenza Viruses with Allele A and B Nonstructural Gene in Northern Pintail (Anas acuta) Ducks Wintering in Japan

Abstract

The pandemic influenza virus strains of 1918 (H1N1), 1957 (H2N2), 1968 (H3N2), and 2009 (H1N1) have genes related to avian influenza viruses (AIVs). The nonstructural (NS) gene of AIVs plays a significant role in host-viral interaction. However, little is known about the degree of diversity of this gene in Northern pintail (Anas acuta) ducks wintering in Japan. This study describes characteristics of pintail-originated H1N1, H1N2, H1N3, H5N2, H5N3, H5N9, and H7N7 viruses. Most of the viruses were revealed to be avian strains and not related to pandemic and seasonal flu strains. Nevertheless, the NP genes of 62.5% (5/8) viruses were found closely related to a A/swine/Korea/C12/08, indicating exchange of genetic material and ongoing mammalian-linked evolution of AIVs. Besides, all the viruses, except Aomori/422/07 H1N1, contain PSIQSR∗GLF motif usually found in avian, porcine, and human H1 strains. The Aomori/422/07 H1N1 has a PSVQSR∗GLF motif identical to a North American strain. This findings linked to an important intercontinental, Asian-American biogeographical interface. Phylogenetically all the viruses were clustered in Eurasian lineage. Cocirculation of allele A and B (NS gene) viruses was evident in the study implying the existence of a wide reservoir of influenza A viruses in pintail wintering in Japan.

Surveillance for avian influenza viruses in wild birds at live bird markets, Egypt, 2014‐2016

“…NS gene of A/Pintail/Egypt/MB.D384C/2015(H3N6) was categorized as allele B with Eurasian LPAIVs, while the remaining isolates were categorized as allele A (Figure ). Previous studies showed that the allele A AIVs are more common than allele B . Co‐circulation of allele A and B viruses was previously detected in Northern Pintail in Japan during 2007‐2008 …”

“…Previous studies showed that the allele A AIVs are more common than allele B . Co‐circulation of allele A and B viruses was previously detected in Northern Pintail in Japan during 2007‐2008 …”

“…Previous studies showed that the allele A AIVs are more common than allele B. 29,30 Co-circulation of allele A and B viruses was previously detected in Northern Pintail in Japan during 2007-2008. 30 Our findings show the role of wild aquatic birds in transcontinental virus transmission and provide evidence of continuing reassortment of the different subtypes of AIVs.…”

“…29,30 Co-circulation of allele A and B viruses was previously detected in Northern Pintail in Japan during 2007-2008. 30 Our findings show the role of wild aquatic birds in transcontinental virus transmission and provide evidence of continuing reassortment of the different subtypes of AIVs. 31 was restricted to a single species; hence, comparison to Damietta does not provide a significant conclusion.…”

Genetic diversity of H5N1 and H5N2 high pathogenicity avian influenza viruses isolated from poultry in Japan during the winter of 2022–2023

“…NS genes of allele B were found mainly in IAVs of avian origin. A previous study suggests that allele B is not common in natural hosts than allele A ( Jahangir et al, 2012 ). While 6 of 11 genotypes in G2c have AIV NS-II belonging allele B ( Table 1 ), the numbers of outbreaks caused by these viruses were limited (10 of 57 outbreaks).…”