Different Pathogenicity and Transmissibility of Goose-Origin H5N6 Avian Influenza Viruses in Chickens

Abstract

Highly pathogenic avian influenza H5N6 viruses have been circulating in poultry in Asia since 2013 and producing serious diseases in chickens. Here, we analyzed the genetic properties of 10 H5N6 subtypes AIVs from geese in 2015–2016 in Guangdong province. Phylogenic analysis showed that all HA genes of the 10 viruses belonged to clade 2.3.4.4, and their genes including HA, PA, PB1, M, NP, and NS all derived from Mix-like 1 (CH, VN, LS). Their PB2 genes come from Mix-like 2 (CH, VN, JP). The NA genes were classified into a Eurasian lineage. Therefore, the 10 viruses likely originate from the same ancestor and were all recombinant viruses between different genotypes. We selected A/Goose/Guangdong/GS144/2015(H5N6) (GS144) and A/Goose/Guangdong/GS148/2016(H5N6) (GS148) viruses to inoculate 5-week-old chickens intranasally with 104 EID50/0.1 mL dose intranasally to assess their pathogenicity and transmissibility. Inoculated chickens showed that the GS144 virus caused systematic infection with a lethality of 100%, but the lethality of GS148 virus was 0%. The two viruses were efficiently transmitted to contact chickens. The lethality of GS144 and GS148 virus in contact with chickens was 87.5% and 0%, respectively, which suggests that the transmissibility of GS144 virus was stronger than GS148 virus in chickens. Thus, different H5N6 viruses from the same waterfowl can show different pathogenicity and transmissibility in chickens. Continued surveillance and characteristic analysis of the H5N6 viruses will help us to keep abreast of evolution and variation in avian influenza viruses in the future.

Characterization of four novel H5N6 avian influenza viruses with the internal genes from H5N1 and H9N2 viruses and experimental challenge of chickens vaccinated with current commercially available H5 vaccines

“…Significant mutations may contribute to the evolution, the host specificity and pathogenicity of influenza viruses (Carrat & Flahault, 2007; Shao et al., 2017). Similar to the previous studies (Kwon et al., 2018; Lee et al., 2017; Mei et al., 2019; Mine et al., 2019; Qu et al., 2019; Song et al., 2019; Sun et al., 2018; Uchida et al., 2019), all of the four H5N6 viruses in our study might be highly pathogenic to chickens, which contained a series of multiple basic amino acids in the HA cleavage, and they also could transmit to contact chickens. However, our viruses exhibited high virulence in mice and could replicate lungs, brains, spleens and kidneys.…”

Special Issue “Emerging Viruses: Surveillance, Prevention, Evolution, and Control”

“…They demonstrate relevant host-virus features in chickens and mice, including systemic replication and contact transmission between chickens, and upregulation of PRR in different organs in chicken and mice. Mei et al [6] also reveal that goose-origin H5N6 avian influenza viruses have different pathogenicity and transmissibility in chickens. Yu et al [7] present a comparative analysis between highly and low pathogenic H7N9 AIV strains.…”

Phylogenetic and Pathogenicity Comparison of Three H5N6 Avian Influenza Viruses in Chickens, Ducks and Mice

“…Changes at these sites suggest that the ability of the virus to infect humans across species may be enhanced. Recent studies have found that changes in some glycosylation sites of HA protein play an important role in virus proliferation, infectivity and transmission [31,32]. The glycosylation sites of the HA gene of the virus strain in this study were between 8 and 9.…”