Genetic Characterization of Avian Influenza A (H11N9) Virus Isolated from Mandarin Ducks in South Korea in 2018

In July 2018, a novel avian influenza virus (A/Mandarin duck/South Korea/KNU18-12/2018(H11N9)) was isolated from Mandarin ducks in South Korea. Phylogenetic and molecular analyses were conducted to characterize the genetic origins of the H11N9 strain. Phylogenetic analysis indicated that eight gene segments of strain H11N9 belonged to the Eurasian lineages. Analysis of nucleotide sequence similarity of both the hemagglutinin (HA) and neuraminidase (NA) genes revealed the highest homology with A/duck/Kagoshima/KU57/2014 (H11N9), showing 97.70% and 98.00% nucleotide identities, respectively. Additionally, internal genes showed homology higher than 98% compared to those of other isolates derived from duck and wild birds. Both the polymerase acidic (PA) and polymerase basic 1 (PB1) genes were close to the H5N3 strain isolated in China; whereas, other internal genes were closely related to that of avian influenza virus in Japan. A single basic amino acid at the HA cleavage site (PAIASR↓GLF), the lack of a five-amino acid deletion (residue 69–73) in the stalk region of the NA gene, and E627 in the polymerase basic 2 (PB2) gene indicated that the A/Mandarin duck/South Korea/KNU18-12/2018(H11N9) isolate was a typical low-pathogenicity avian influenza. In vitro viral replication of H11N9 showed a lower titer than H1N1 and higher than H9N2. In mice, H11N9 showed lower adaptation than H1N1. The novel A/Mandarin duck/South Korea/KNU18-12/2018(H11N9) isolate may have resulted from an unknown reassortment through the import of multiple wild birds in Japan and Korea in approximately 2016–2017, evolving to produce a different H11N9 compared to the previous H11N9 in Korea (2016). Further reassortment events of this virus occurred in PB1 and PA in China-derived strains. These results indicate that Japanese- and Chinese-derived avian influenza contributes to the genetic diversity of A/Mandarin duck/South Korea/KNU18-12/2018(H11N9) in Korea.

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Molecular Characterization of a Novel Avian Influenza A (H2N9) Strain Isolated from Wild Duck in Korea in 2018

Viruses ◽

10.3390/v11111046 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1046 ◽

Cited By ~ 4

Author(s):

Seon-Ju Yeo ◽

Duc-Duong Than ◽

Hong-Seog Park ◽

Haan Woo Sung ◽

Hyun Park

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Influenza A ◽

Matrix Protein ◽

Sequence Similarity ◽

Wild Birds ◽

Structural Protein ◽

Wild Duck

A novel avian influenza virus (A/wild duck/Korea/K102/2018) (H2N9) was isolated from wild birds in South Korea in 2018, and phylogenetic and molecular analyses were conducted on complete gene sequences obtained by next-generation sequencing. Phylogenetic analysis indicated that the hemagglutinin (HA) and neuraminidase (NA) genes of the A/wild duck/Korea/K102/2018 (H2N9) virus belonged to the Eurasian countries, whereas other internal genes (polymerase basic protein 1 (PB1), PB2, nucleoprotein (NP), polymerase acidic protein (PA), matrix protein (M), and non-structural protein (NS)) belonged to the East Asian countries. A monobasic amino acid (PQIEPR/GLF) at the HA cleavage site, E627 in the PB2 gene, and no deletion of the stalk region in the NA gene indicated that the A/wild duck/Korea/K102/2018 (H2N9) isolate was a typical low pathogenicity avian influenza (LPAI). Nucleotide sequence similarity analysis of HA revealed that the highest homology (98.34%) is to that of A/duck/Mongolia/482/2015 (H2N3), and amino acid sequence of NA was closely related to that of A/duck/Bangladesh/8987/2010 (H10N9) (96.45%). In contrast, internal genes showed homology higher than 98% compared to those of other isolates derived from duck and wild birds of China or Japan in 2016–2018. The newly isolated A/wild duck/Korea/K102/2018 (H2N9) strain is the first reported avian influenza virus in Korea, and may have evolved from multiple genotypes in wild birds and ducks in Mongolia, China, and Japan.

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Genetic Characterization and Pathogenesis of Avian Influenza Virus H7N3 Isolated from Spot-Billed Ducks in South Korea, Early 2019

Viruses ◽

10.3390/v13050856 ◽

2021 ◽

Vol 13 (5) ◽

pp. 856

Author(s):

Thuy-Tien Thi Trinh ◽

Indira Tiwari ◽

Kaliannan Durairaj ◽

Bao Tuan Duong ◽

Anh Thi Viet Nguyen ◽

...

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

South Korea ◽

Avian Influenza Virus ◽

Post Infection ◽

Influenza Viruses ◽

Avian Influenza Viruses ◽

Highly Pathogenic

Low-pathogenicity avian influenza viruses (LPAIV) introduced by migratory birds circulate in wild birds and can be transmitted to poultry. These viruses can mutate to become highly pathogenic avian influenza viruses causing severe disease and death in poultry. In March 2019, an H7N3 avian influenza virus—A/Spot-billed duck/South Korea/WKU2019-1/2019 (H7N3)—was isolated from spot-billed ducks in South Korea. This study aimed to evaluate the phylogenetic and mutational analysis of this isolate. Molecular analysis revealed that the genes for HA (hemagglutinin) and NA (neuraminidase) of this strain belonged to the Central Asian lineage, whereas genes for other internal proteins such as polymerase basic protein 1 (PB1), PB2, nucleoprotein, polymerase acidic protein, matrix protein, and non-structural protein belonged to that of the Korean lineage. In addition, a monobasic amino acid (PQIEPR/GLF) at the HA cleavage site, and the non-deletion of the stalk region in the NA gene indicated that this isolate was a typical LPAIV. Nucleotide sequence similarity analysis of HA revealed that the highest homology (99.51%) of this isolate is to that of A/common teal/Shanghai/CM1216/2017 (H7N7), and amino acid sequence of NA (99.48%) was closely related to that of A/teal/Egypt/MB-D-487OP/2016 (H7N3). An in vitro propagation of the A/Spot-billed duck/South Korea/WKU2019-1/2019(H7N3) virus showed highest (7.38 Log10 TCID50/mL) virus titer at 60 h post-infection, and in experimental mouse lungs, the virus was detected at six days’ post-infection. Our study characterizes genetic mutations, as well as pathogenesis in both in vitro and in vivo model of a new Korea H7N3 viruses in 2019, carrying multiple potential mutations to become highly pathogenic and develop an ability to infect humans; thus, emphasizing the need for routine surveillance of avian influenza viruses in wild birds.

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Characterization of H9N2 influenza A viruses isolated from chicken products imported into Japan from China

Epidemiology and Infection ◽

10.1017/s0950268806006728 ◽

2006 ◽

Vol 135 (3) ◽

pp. 386-391 ◽

Cited By ~ 13

Author(s):

M. MASE ◽

M. ETO ◽

K. IMAI ◽

K. TSUKAMOTO ◽

S. YAMAGUCHI

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Influenza A ◽

H9n2 Virus ◽

Amino Acid Substitutions ◽

Influenza A Viruses ◽

Potential Sources

We characterized eleven H9N2 influenza A viruses isolated from chicken products imported from China. Genetically they were classified into six distinct genotypes, including five already known genotypes and one novel genotype. This suggested that such multiple genotypes of the H9N2 virus have possibly already become widespread and endemic in China. Two isolates have amino-acid substitutions that confer resistance to amantadine in the M2 region, and this supported the evidence that this mutation might be a result of the wide application of amantadine for avian influenza treatment in China. These findings emphasize the importance of surveillance for avian influenza virus in this region, and of quarantining imported chicken products as potential sources for the introduction of influenza virus.

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Biologic effects of introducing additional basic amino acid residues into the hemagglutinin cleavage site of a virulent avian influenza virus

Virus Research ◽

10.1016/s0168-1702(97)00050-6 ◽

1997 ◽

Vol 50 (1) ◽

pp. 35-40 ◽

Cited By ~ 27

Author(s):

Taisuke Horimoto ◽

Yoshihiro Kawaoka

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Cleavage Site ◽

Basic Amino Acid ◽

Amino Acid Residues ◽

Biologic Effects

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The Emergence of H7N7 Highly Pathogenic Avian Influenza Virus from Low Pathogenicity Avian Influenza Virus Using an in ovo Embryo Culture Model

Viruses ◽

10.3390/v12090920 ◽

2020 ◽

Vol 12 (9) ◽

pp. 920

Author(s):

Amanda Seekings ◽

Wendy Howard ◽

Alejandro Nuñéz ◽

Marek Slomka ◽

Ashley Banyard ◽

...

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Cleavage Site ◽

Highly Pathogenic Avian Influenza ◽

Basic Amino Acid ◽

Highly Pathogenic ◽

Pathogenic Avian Influenza ◽

Pathogenic Avian Influenza Virus

Outbreaks of highly pathogenic avian influenza virus (HPAIV) often result in the infection of millions of poultry, causing up to 100% mortality. HPAIV has been shown to emerge from low pathogenicity avian influenza virus (LPAIV) in field outbreaks. Direct evidence for the emergence of H7N7 HPAIV from a LPAIV precursor with a rare di-basic cleavage site (DBCS) was identified in the UK in 2008. The DBCS contained an additional basic amino acid compared to commonly circulating LPAIVs that harbor a single-basic amino acid at the cleavage site (SBCS). Using reverse genetics, outbreak HPAIVs were rescued with a DBCS (H7N7DB), as seen in the LPAIV precursor or an SBCS representative of common H7 LPAIVs (H7N7SB). Passage of H7N7DB in chicken embryo tissues showed spontaneous evolution to a HPAIV. In contrast, deep sequencing of extracts from embryo tissues in which H7N7SB was serially passaged showed retention of the LPAIV genotype. Thus, in chicken embryos, an H7N7 virus containing a DBCS appears naturally unstable, enabling rapid evolution to HPAIV. Evaluation in embryo tissue presents a useful approach to study AIV evolution and allows a laboratory-based dissection of molecular mechanisms behind the emergence of HPAIV.

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Isolation and characterization of low pathogenic H7N7 avian influenza virus from a red-crowned crane in a zoo in South Korea

BMC Veterinary Research ◽

10.1186/s12917-020-02645-4 ◽

2020 ◽

Vol 16 (1) ◽

Author(s):

Young-Jae Si ◽

Yu-Na Lee ◽

Sun-Ha Cheon ◽

Yu-Ri Park ◽

Yoon-Gi Baek ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

South Korea ◽

Avian Influenza Virus ◽

Wild Bird ◽

Wild Birds ◽

Nucleotide Sequencing ◽

Isolation And Characterization ◽

Constellation Analysis ◽

Surveillance Programs

Abstract Background South Korea conducts annual national surveillance programs to detect avian influenza (AI) in domestic poultry, live bird markets, and wild birds. In March 2017, an AIV was isolated from fecal samples in an outdoor aviary flight cage in a zoo in Korea. Results Nucleotide sequencing identified the isolate as low pathogenic avian influenza virus (LPAIV) H7N7, and DNA barcoding analysis identified the host species as red-crowned crane. This isolate was designated A/red-crowned crane/Korea/H1026/2017 (H7N7). Genetic analysis and gene constellation analysis revealed that A/red-crowned crane/Korea/H1026/2017 (H7N7) showed high similarity with four H7N7 LPAIVs isolated from wild bird habitats in Seoul and Gyeonggi in early 2017. Conclusions Considering the genetic similarity and similar collection dates of the viruses, and the fact that zoo bird cages are vulnerable to AIV, it is likely that fecal contamination from wild birds might have introduced LPAIV H7N7 into the red-crowned crane at the zoo. Therefore, our results emphasize that enhanced biosecurity measures should be employed during the wild bird migration season, and that continued surveillance should be undertaken to prevent potential threats to avian species in zoos and to humans.

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A 113-amino-acid truncation at the NS1 C-terminus is a determinant for viral replication of H5N6 avian influenza virus in vitro and in vivo

Veterinary Microbiology ◽

10.1016/j.vetmic.2018.09.004 ◽

2018 ◽

Vol 225 ◽

pp. 6-16 ◽

Cited By ~ 1

Author(s):

Xiaole Cui ◽

Yanhong Ji ◽

Zhengxiang Wang ◽

Yingying Du ◽

Haoran Guo ◽

...

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Viral Replication ◽

Avian Influenza Virus ◽

C Terminus

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Prevalence of avian influenza virus in wild birds before and after the HPAI H5N8 outbreak in 2014 in South Korea

The Journal of Microbiology ◽

10.1007/s12275-015-5224-z ◽

2015 ◽

Vol 53 (7) ◽

pp. 475-480 ◽

Cited By ~ 10

Author(s):

Jeong-Hwa Shin ◽

Chanjin Woo ◽

Seung-Jun Wang ◽

Jipseol Jeong ◽

In-Jung An ◽

...

Keyword(s):

Influenza Virus ◽

Avian Influenza ◽

South Korea ◽

Avian Influenza Virus ◽

Wild Birds ◽

Before And After

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The Effects of Genetic Variation on H7N9 Avian Influenza Virus Pathogenicity

Viruses ◽

10.3390/v12111220 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1220

Author(s):

Szu-Wei Huang ◽

Sheng-Fan Wang

Keyword(s):

Influenza Virus ◽

Amino Acid ◽

Avian Influenza ◽

Avian Influenza Virus ◽

Influenza A ◽

Influenza A Viruses ◽

Potential Threat ◽

Amino Acid Insertion ◽

Live Poultry ◽

Human Infections

Since the H7N9 avian influenza virus emerged in China in 2013, there have been five seasonal waves which have shown human infections and caused high fatality rates in infected patients. A multibasic amino acid insertion seen in the HA of current H7N9 viruses occurred through natural evolution and reassortment, and created a high pathogenicity avian influenza (HPAI) virus from the low pathogenicity avian influenza (LPAI) in 2017, and significantly increased pathogenicity in poultry, resulting in widespread HPAI H7N9 in poultry, which along with LPAI H7N9, contributed to the severe fifth seasonal wave in China. H7N9 is a novel reassorted virus from three different subtypes of influenza A viruses (IAVs) which displays a great potential threat to public health and the poultry industry. To date, no sustained human-to-human transmission has been recorded by the WHO. However, the high ability of evolutionary adaptation of H7N9 and lack of pre-existing immunity in humans heightens the pandemic potential. Changes in IAVs proteins can affect the viral transmissibility, receptor binding specificity, pathogenicity, and virulence. The multibasic amino acid insertion, mutations in hemagglutinin, deletion and mutations in neuraminidase, and mutations in PB2 contribute to different virological characteristics. This review summarized the latest research evidence to describe the impacts of viral protein changes in viral adaptation and pathogenicity of H7N9, aiming to provide better insights for developing and enhancing early warning or intervention strategies with the goal of preventing highly pathogenic IAVs circulation in live poultry, and transmission to humans.

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