Characterization of a Chicken Embryo-Adapted H9N2 Subtype Avian Influenza Virus

Kwon, Hyuk‐Joon; Cho, Sun-Hee; Ahn, Youngjin; Kim, Jae Hong; Yoo, Heejin; Kim, Sun-Joong

doi:10.2174/1874318800903010009

Cited by 4 publications

(3 citation statements)

References 45 publications

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“…In Korea, nationwide occurrences of LPAI caused by AIV H9N2 have been reported since the first outbreak of the disease in 1996 and have caused mild disease with up to 30% mortality in broiler breeder flocks [22]. To date, the disease has increased and has become endemic [21,23]. Under certain conditions, Korean isolates have evolved causing 30% mortality and a severe decrease in egg production in layers that were experimentally infected [19].…”

Section: Discussionmentioning

confidence: 99%

Genetic and biological characteristics of recent Korean isolates of avian influenza virus subtype H9N2

Acharya¹,

Kwon²,

Kim³

et al. 2012

Korean J Vet Res

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The worldwide distribution and continuing genetic mutation of avian influenza virus (AIV) has been posed a great threat to human and animal health. A comparison of 3 isolates of AIV H9N2, A/chicken/Korea/KBNP-0028/ 00 (H9N2) (KBNP-0028), A/chicken/Korea/SNU8011/08 (H9N2) (SNU 8011) and an inactivated oil vaccine strain A/chicken/Korea/01310/01 (H9N2) ( 01310), was performed. The former 2 AIVs were isolated from field cases before and after the application of an inactivated H9N2 vaccine in 2007, respectively. The antigenic relationship, viral shedding, tissue tropism and genetic analysis were examined. The comparison of virus shedding from the cloaca and the oropharynx revealed that both isolates were more frequently isolated from the upper respiratory tract (90~100%) 1 day post inoculation (DPI) compared with isolation 5 DPI from gastrointestinal tracts (10~60%). Moreover, the isolate KBNP-0028 were recovered from all organs including bone marrow, brain and kidneys, indicating higher ability for broad tissue dissemination than that of SNU 8011. KBNP-0028 replicated earlier than other strains and with a higher titer than SNU 8011. In full-length nucleotide sequences of the NA gene and a partial sequence of the HA gene of SNU 8011, we found that there might be significant changes in tissue tropism, virus replication and genetic mutation in AIV H9N2 isolates.

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Section: Discussionmentioning

confidence: 99%

Genetic and biological characteristics of recent Korean isolates of avian influenza virus subtype H9N2

Acharya¹,

Kwon²,

Kim³

et al. 2012

Korean J Vet Res

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“…HA and NA genomes of recombinant H5N6 virus were synthesized in the sequence most frequent among clade 2.3.4.4c H5N6 isolates during the years 2014–2016 ( n = 73) (Cosmo Genetech, Seoul, Korea), with a change in cleavage site from a polybasic amino acid (RERRKR) site to the monobasic amino acid (ASGR) site of the Korean H9N2 LPAI virus, A/chicken/Korea/KBNP- 0028 /00( H9N2 ) ( 0028 ) [ 24 ]. Internal genes of PR8, LPAIV H9N2 01310, 0028 and LPAI A/wild duck/Korea/SNU50-5/2009(H5N1) (SNU50-5) were used to generate recombinant H5N6 strains possessing internal proteins of PR8 or avian IAVs (Influenza A viruses) [ 12 , 22 , 23 ].…”

Section: Methodsmentioning

confidence: 99%

Improvement of PR8-Derived Recombinant Clade 2.3.4.4c H5N6 Vaccine Strains by Optimization of Internal Genes and H103Y Mutation of Hemagglutinin

Hong

Son

et al. 2020

Vaccines

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Clade 2.3.4.4c H5N6 avian influenza A viruses (AIVs) may have originally adapted to infect chickens and have caused highly pathogenic avian influenza (HPAI) in poultry and human fatalities. Although A/Puerto Rico/8/1934 (H1N1) (PR8)-derived recombinant clade 2.3.4.4c H5N6 vaccine strains have been effective in embryonated chicken eggs-based vaccine production system, they need to be improved in terms of immunogenicity and potential mammalian pathogenicity. We replaced the PB2 gene alone or the PB2 (polymerase basic protein 2), NP (nucleoprotein), M (matrix protein) and NS (non-structural protein) genes together in the PR8 strain with corresponding genes from AIVs with low pathogenicity to remove mammalian pathogenicity and to match CD8+ T cell epitopes with contemporary HPAI viruses, respectively, without loss of viral fitness. Additionally, we tested the effect of the H103Y mutation of hemagglutinin (HA) on antigen productivity, mammalian pathogenicity and heat/acid stability. The replacement of PB2 genes and the H103Y mutation reduced the mammalian pathogenicity but increased the antigen productivity of the recombinant vaccine strains. The H103Y mutation increased heat stability but unexpectedly decreased acid stability, probably resulting in increased activation pH for HA. Interestingly, vaccination with inactivated recombinant virus with replaced NP, M and NS genes halted challenge virus shedding earlier than the recombinant vaccine without internal genes replacement. In conclusion, we successfully generated recombinant clade 2.3.4.4c H5N6 vaccine strains that were less pathogenic to mammals and more productive and heat stable than conventional PR8-derived recombinant strains by optimization of internal genes and the H103Y mutation of HA.

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“…For genetic analysis of HA gene of H9N2, the HA cleavage site contains single basic amino acids 'SRSSR' which known as the characteristics of low pathogenic avian influenza. It has been reported that the numbers of basic amino acid at the HA cleavage site may affect the pathogenesis of influenza virus due to the HA protein has to be cleaved by cellular protease enzyme of the host (Kwon et al, 2009). In this study, the H9N2 virus harbored 155-Threonine (T), 183-asparagine (N) and 226-Leucine (L) amino acids at receptor binding site indicating human specific receptor binding site.…”

Section: Genetic Analysis Of Internal Genes Of H5n1 Virusesmentioning

confidence: 84%

Genetic characteristics of avian influenza viruses isolated from ducks in Java Island, Indonesia year 2015-2017

Lestari

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Avian influenza becomes public health concern over years due to the serious impacts in both animal and human health. This study aimed to identify and characterize avian influenza viruses isolated from ducks in Java Indonesia during 2015-2017. Total 50 samples of previously identified as avian influenza viruses were acquired from the virus/culture collections of Disease Investigation Center (DIC) Wates Yogyakarta, Indonesia. The samples were recovered from either the avian influenza surveillance or avian influenza outbreaks in ducks in 3 provinces, East Java (n=26), Central Java (n=16), and Yogyakarta (n=8). Then the samples were processed for influenza A virus screening by realtime RT-PCR using M gene specific primers. The results showed that 46 out of 50 samples (92%) were positive for influenza A virus screening. The positive samples were then subjected for influenza A virus isolation. Seven out of 46 samples were positive for influenza A virus confirmation by using multi-segment reverse transcription PCR (M-RTPCR). All 7 avian influenza viruses were subjected to whole genome sequencing by next generation sequencing. The viruses were then identified as avian influenza subtype H5N1 (n=6) and H9N2 (n=1). Phylogenetic analysis showed that the avian influenza viruses were clustered into H5N1 virus of clade 2.3.2.1c (n=6) and H9N2 viruses of Y280-like group (n=1). Phylogenetic analysis of internal genes indicated that among the H5N1 of clade 2.3.2.1c (n=1), the evidence of inter-lineage reassortment by acquiring the M gene from H5N1 of clade 2.1.3.2 could be observed. On the other hand, phylogenetic analysis of H9N2 showed that all internal genes of H9N2 were closely related to the human H7N9 virus isolated from China. Genetic analysis showed that the H5N1 and H9N2 viruses were categorized as HPAI and LPAI, respectively. In conclusion, our results suggested that both HPAI-H5N1 and LPAI-H9N2 were circulated in ducks in Java, Indonesia. Routine surveillance and genetic characterization are important to monitor the dynamic and genetic diversity of avian influenza viruses and possibility of novel reassortment strains.

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Characterization of a Chicken Embryo-Adapted H9N2 Subtype Avian Influenza Virus

Cited by 4 publications

References 45 publications

Genetic and biological characteristics of recent Korean isolates of avian influenza virus subtype H9N2

Genetic and biological characteristics of recent Korean isolates of avian influenza virus subtype H9N2

Improvement of PR8-Derived Recombinant Clade 2.3.4.4c H5N6 Vaccine Strains by Optimization of Internal Genes and H103Y Mutation of Hemagglutinin

Genetic characteristics of avian influenza viruses isolated from ducks in Java Island, Indonesia year 2015-2017

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