Evolutionary characterization of hemagglutinin gene of H9N2 influenza viruses isolated from Asia

Shahsavandi, Shahla; Salmanian, Ali-Hatef; Ghorashi, Seyed A.; Masoudi, Shahin; Ebrahimi, Mohammad Majid

doi:10.1016/j.rvsc.2011.07.033

Cited by 21 publications

(25 citation statements)

References 20 publications

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“…In Iranian isolates, substitutions in this position (A→T, A→I, A→V) have happened in some recent isolates. In one of the viruses sequenced in this study (N101), amino acid Threonine has replaced Alanine, indicating high affinity for human airway epithelial receptors (Table 1) (13,20,35,36). On the other hands, all Iranian isolates fell into the same main group (G1 sublineage) as the viruses isolated in Pakistan, Saudi Arabia, UAE, India and Israel, indicating they might have originated from a common source (Fig 1a).…”

Section: Discussionmentioning

confidence: 77%

“…It should be emphasized, that all H9N2 viruses with two or three basic amino acids in the cleavage site have had low pathogenicity for chickens (19,18). Some researchers suggested that -RSSR*G-motif is the signature of H9N2 LPAI viruses adapted to the chicken host (16,18,20). It is interesting that all of these mutations in Iranian isolates have happened after 2007.…”

Section: Discussionmentioning

confidence: 99%

“…So, there may be a relationship between time and happening of mutations in AIVs, as observed in Israeli isolates (19). AI H9N2 viruses have some capabilities to transmit from bird to human and are a candidate for next human flu pandemic (20). The RBS motif of HA is critical for cellular receptor specificity and determining virus host range (21,22).…”

Section: Discussionmentioning

confidence: 99%

“…On the other hands, all Iranian isolates fell into the same main group (G1 sublineage) as the viruses isolated in Pakistan, Saudi Arabia, UAE, India and Israel, indicating they might have originated from a common source (Fig 1a). However, Middle East isolates showed a relationship that may indicate some ecological barriers to virus movement based around geographic location, with isolates grouped according to country of isolation (20). The Iranian isolates can be further divided into two main subgroups (Fig 1b).…”

Section: Discussionmentioning

confidence: 99%

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Phylogenetic Analysis of Hemagglutinin Gene of H9N2 Avian Influenza Viruses Isolated from Chicken in Iran in 2010-2011: Emerging of a New Subgroup

2012

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Background and Aims: Hemagglutinin (HA) protein of Avian Influenza (AI) plays an essential role in the virus pathogenicity. AI H9N2 subtype causes significant economic loss in broiler and layer in poultry farms in Iran. AI viruses have a great involvement in evolutionary changes at nucleotide and amino acid levels and vaccines could induce faster rates of such changes. Up-dated understanding of the genetic changes of AI viruses circulating in Iran is necessary for controlling AI. Materials and Methods: Sequence analysis and phylogenetic study of the HA gene of three H9N2 subtype of AI isolates in Iran in 2010-2011 were studied. Results: Cleavage site of the Iranian 2010-2011 isolates possessed a different motif. Amino acid residue at position 226 at receptor binding site in these isolates was Leucine, which was similar to human viruses. The epitopes for HA showed a great variation related to the year of isolation. According to phylogenetic analysis, Iranian isolates were divided into two main subgroups. But, viruses isolated in this study formed a third minor subgroup. Degree of homology between the 2010-2011 isolates and former Iranian isolates was significantly low. Conclusion:The results revealed that HA of new Iranian AI H9N2 isolates have undergone extensive genetic changes. Definitely, continuous monitoring of genetic changes is a useful tool for updating control strategy for AI outbreak in Iran.

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Section: Discussionmentioning

confidence: 77%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Phylogenetic Analysis of Hemagglutinin Gene of H9N2 Avian Influenza Viruses Isolated from Chicken in Iran in 2010-2011: Emerging of a New Subgroup

2012

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“…An egg-adapted H9N2 virus (Shahsavandi et al 2012) was used as a seed for infection of CEF and CTE cells. The virus was titrated according to Swayne et al (2008).…”

Section: Virusmentioning

confidence: 99%

Impact of chicken-origin cells on adaptation of a low pathogenic influenza virus

et al. 2012

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Understanding the growth dynamics of influenza viruses is an essential step in virus replication and cell-adaptation. The aim of this study was to elucidate the growth kinetic of a low pathogenic avian influenza H9N2 subtype in chicken embryo fibroblast (CEF) and chicken tracheal epithelial (CTE) cells during consecutive passages. An egg-adapted H9N2 virus was seeded into both cell culture systems. The amount of infectious virus released into the cell culture supernatants at interval times post-infection were titered and plaque assayed. The results as well as cell viability results indicate that the infectivity of the influenza virus was different among these primary cells. The egg-adapted H9N2 virus featured higher infectivity in CTE than in CEF cells. After serial passages and plaque purifications of the virus, a CTE cell-adapted strain was generated which carried amino acid substitutions within the HA stem region. The strain showed faster replication kinetics in cell culture resulting in an increase in virus titer. Overall, the present study provides the impact of cell type, multiplicity of infection, cellular protease roles in virus infectivity and finally molecular characterization during H9N2 virus adaptation procedure.

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Low‐pathogenicity avian influenza

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Wit

2016

Animal Influenza

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Evolutionary characterization of hemagglutinin gene of H9N2 influenza viruses isolated from Asia

Cited by 21 publications

References 20 publications

Phylogenetic Analysis of Hemagglutinin Gene of H9N2 Avian Influenza Viruses Isolated from Chicken in Iran in 2010-2011: Emerging of a New Subgroup

Phylogenetic Analysis of Hemagglutinin Gene of H9N2 Avian Influenza Viruses Isolated from Chicken in Iran in 2010-2011: Emerging of a New Subgroup

Impact of chicken-origin cells on adaptation of a low pathogenic influenza virus

Low‐pathogenicity avian influenza

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