Characterization of two chicken origin highly pathogenic H7N9 viruses isolated in northern China

Gu, Jun; Yan, Yayao; Zeng, Zixiong; Wang, Wenli; Gao, Ruyi; Hu, Jiao; Hu, Shunlin; Wang, Xiaoquan; Gu, Minghong; Liu, Xiufan

doi:10.1016/j.vetmic.2022.109394

Cited by 6 publications

(6 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, among these newly emerged H7N9 AIVs, HB/20 and SX/21 completely lost the receptor binding towards human-like 6SLN receptor analogues while YN/21 showed ∼39 folds of reduction in its binding towards human-like 6SLN receptor analogues when compared with AH/13. Our finding agrees with previous reports showing that the H7N9 AIVs from 2018 to 2020 gradually lost receptor binding to human-type receptors measured by solid-phase direct binding assay [ 28 , 29 ]. We have previously shown that the threonine at residues 125 and 151 in HA formed N-linked glycosylation motifs (N-X-T/S, where X is any amino acid other than proline) and resulted in the addition of glycan to the asparagine at amino acid residue 123 and 149, which was further validated by Yin et al [ 9 , 29 ].…”

Section: Discussionsupporting

confidence: 93%

Risk assessment of the newly emerged H7N9 avian influenza viruses

Chang

Sadeyen

Bhat

et al. 2023

Emerging Microbes & Infections

View full text Add to dashboard Cite

Since the first human case in 2013, H7N9 avian influenza viruses (AIVs) have caused more than 1500 human infections with a mortality rate of approximately 40%. Despite large-scale poultry vaccination regimes across China, the H7N9 AIVs continue to persist and evolve rapidly in poultry. Recently, several strains of H7N9 AIVs have been isolated and shown the ability to escape vaccine-induced immunity. To assess the zoonotic risk of the recent H7N9 AIV isolates, we rescued viruses with hemagglutinin (HA) and neuraminidase (NA) from these H7N9 AIVs and six internal segments from PR8 virus and characterized their receptor binding, pH of fusion, thermal stability, plaque morphology and in ovo virus replication. We also assessed the cross-reactivity of the viruses with human monoclonal antibodies (mAbs) against H7N9 HA and ferret antisera against H7N9 AIV candidate vaccines. The H7N9 AIVs from the early epidemic waves had dual sialic acid receptor binding characteristics, whereas the more recent H7N9 AIVs completely lost or retained only weak human sialic acid receptor binding. Compared with the H7N9 AIVs from the first epidemic wave, the 2020/21 viruses formed larger plaques in Madin-Darby canine kidney (MDCK) cells and replicated to higher titres in ovo , demonstrating increased acid stability but reduced thermal stability. Further analysis showed that these recent H7N9 AIVs had poor cross-reactivity with the human mAbs and ferret antisera, highlighting the need to update the vaccine candidates. To conclude, the newly emerged H7N9 AIVs showed characteristics of typical AIVs, posing reduced zoonotic risk but a heightened threat for poultry.

show abstract

Section: Discussionsupporting

confidence: 93%

Risk assessment of the newly emerged H7N9 avian influenza viruses

Chang

Sadeyen

Bhat

et al. 2023

Emerging Microbes & Infections

View full text Add to dashboard Cite

show abstract

“…In general, avian-origin H7N9 viruses were lowly pathogenic in mammals without long-term adaptation [39,46]. In our study, the two H7N9 isolates have a similar genetic background, but there were significant differences in pathogenicity in mice (JTC4, MLD 50 > 10 6.5 EID 50 ; JTC11, MLD 50 = 10 3.5 EID 50 ).…”

Section: Discussionmentioning

confidence: 53%

“…In addition, H7N9 displayed antigenicity variation during circulation [38,[41][42][43], which facilitates virus evasion of the immune response. Moreover, H7N9 also obtained a higher binding capability for α2,6-sialic acid receptors [39], retaining the ability to infect humans. Thus, it is necessary to maintain a high level of attention to H7N9 AIVs.…”

Section: Discussionmentioning

confidence: 96%

“…The last human case of H7N9 infection was reported in April 2019, which seems to signal that H7N9 is less of a threat to public health security in recent years [15]. Nevertheless, the H7N9 virus has not been eradicated from poultry [38][39][40]. In addition, H7N9 displayed antigenicity variation during circulation [38,[41][42][43], which facilitates virus evasion of the immune response.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Genetically Related Avian Influenza H7N9 Viruses Exhibit Different Pathogenicity in Mice

Wang,

Zheng,

Gao

et al. 2023

Animals

Self Cite

View full text Add to dashboard Cite

Avian influenza viruses can cross species barriers and adapt to mammals. The H7N9 subtype AIV that emerged in China in 2013 caused 1568 human infections, with a mortality rate of nearly 40%. We conducted a retrospective analysis of H7N9 viruses that were isolated in live poultry markets in 2013. We found that two avian-origin H7N9 isolates, A/chicken/Eastern China/JTC4/2013 and A/chicken/Eastern China/JTC11/2013, have a similar genetic background but exhibit different pathogenicity in mice. Whole-genome alignment of the two H7N9 viruses was carried out, and only six amino acid differences mapped in five genes, including the well-known virulence molecular marker PB2-E627K. Our retrospective analysis highlighted the importance of monitoring the adaptive mutations in avian influenza viruses with zoonotic potential.

show abstract

“…After vaccination with the H5/H7 bivalent inactivated vaccine, the prevalence of the H7N9 virus in poultry declined considerably, and human infection has been eliminated ( 7 ). However, the H7N9 influenza virus has not been eradicated in poultry in China ( 8 – 10 ).…”

Section: Introductionmentioning

confidence: 99%