scholarly journals Comparative sequence, antigenic and phylogenetic analysis of avian influenza (H9N2) surface proteins isolated in Pakistan between 1999 and 2008

2011 ◽  
Vol 5 (06) ◽  
pp. 413-424 ◽  
Author(s):  
Azeem Mehmood Butt ◽  
Samerene Siddique ◽  
Shifa Tahir ◽  
Izza Nasrullah ◽  
Mureed Hussain ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Avian Influenza ◽  
Viral Entry ◽  
Influenza A ◽  
Genomic Structure ◽  
Glycosylation Site ◽  
Surface Proteins ◽  
Host Immune System ◽  
Influenza A Viruses ◽  
Substitution Mutations

Introduction: Influenza A viruses possess a unique genomic structure which leads to genetic instability, especially in products of neuraminidase and hemagglutinin genes. These surface proteins play major roles in viral entry and release, and in the activation of the host immune system. Methodology: This study involved an in silico sequence, phylogenetic and antigenic analyses of hemagglutinin and neuraminidase proteins of avian influenza A (H9N2) strains that circulated in Pakistan's poultry flocks from 1999 to 2008 and determined variations among these sequences at different levels. Results: Sequence and phylogenetic analysis revealed a large number of similar substitution mutations and close evolutionary relation among sequences of both proteins. Changes were observed in the N-glycosylation sites of both surface proteins, along with the appearance of a new glycosylation site in the neuraminidase sequence isolated in 2007. Epitopes for hemagglutinin remained conserved, whereas for neuraminidase, epitopes from older strains reappeared in present sequences. Conclusions: Because of the rapid mutating nature of avian influenza subtype H9N2, constant surveillance of annual sequence variations is important. Preventive measures and vaccine products can be evaluated by keeping track of changes that may lead to reassortment among different circulating strains in Pakistan's commercial poultry flocks or in humans.

scholarly journals Sequence characteristics and phylogenetic analysis of H9N2 subtype avian influenza A viruses detected from poultry and the environment in China, 2018

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12512
Author(s):  
Xiaoyi Gao ◽  
Naidi Wang ◽  
Yuhong Chen ◽  
Xiaoxue Gu ◽  
Yuanhui Huang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Avian Influenza ◽  
Influenza A ◽  
Mammalian Species ◽  
Glycosylation Site ◽  
Global Public Health ◽  
Influenza A Viruses ◽  
H9n2 Subtype ◽  
Avian Influenza A Virus ◽  
High Conservation

H9N2 subtype avian influenza A virus (AIV) is a causative agent that poses serious threats to both the poultry industry and global public health. In this study, we performed active surveillance to identify H9N2 AIVs from poultry (chicken, duck, and goose) and the environment of different regions in China, and we phylogenetically characterized the sequences. AIV subtype-specific reverse transcription polymerase chain reaction (RT-PCR) showed that 5.43% (83/1529) samples were AIV positive, and 87.02% (67/77) of which were H9N2 AIVs. Phylogenetic analysis revealed that all H9N2 field viruses belonged to the Y280-like lineage, exhibiting 93.9–100% and 94.6–100% of homology in the hemagglutinin (HA) gene and 94.4–100% and 96.3–100% in the neuraminidase (NA) gene, at the nucleotide (nt) and amino acid (aa) levels, respectively. All field viruses shared relatively lower identities with vaccine strains, ranging from 89.4% to 97.7%. The aa sequence at the cleavage site (aa 333–340) in HA of all the isolated H9N2 AIVs was PSRSSRG/L, which is a characteristic of low pathogenic avian influenza virus (LPAIV). Notably, all the H9N2 field viruses harbored eight glycosylation sites, whereas a glycosylation site 218 NRT was missing and a new site 313 NCS was inserted. All field viruses had NGLMR as their receptor binding sites (RBS) at aa position 224–229, showing high conservation with many recently-isolated H9N2 strains. All H9N2 field isolates at position 226 had the aa Leucine (L), indicating their ability to bind to sialic acid (SA) α, a 2–6 receptor of mammals that poses the potential risk of transmission to humans. Our results suggest that H9N2 AIVs circulating in poultry populations that have genetic variation and the potential of infecting mammalian species are of great significance when monitoring H9N2 AIVs in China.

scholarly journals Isolation and Genetic Characterization of H5N2 Influenza Viruses from Pigs in Korea

2009 ◽  
Vol 83 (9) ◽  
pp. 4205-4215 ◽  
Author(s):  
Jun Han Lee ◽  
Philippe Noriel Q. Pascua ◽  
Min-Suk Song ◽  
Yun Hee Baek ◽  
Chul-Joong Kim ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Animal Experiments ◽  
Influenza Viruses ◽  
Surface Proteins ◽  
Intermediate Hosts ◽  
Influenza A Viruses ◽  
Highly Pathogenic ◽  
Eurasian Lineage

ABSTRACT Due to dual susceptibility to both human and avian influenza A viruses, pigs are believed to be effective intermediate hosts for the spread and production of new viruses with pandemic potential. In early 2008, two swine H5N2 viruses were isolated from our routine swine surveillance in Korea. The sequencing and phylogenetic analysis of surface proteins revealed that the Sw/Korea/C12/08 and Sw/Korea/C13/08 viruses were derived from avian influenza viruses of the Eurasian lineage. However, although the Sw/Korea/C12/08 isolate is an entirely avian-like virus, the Sw/Korea/C13/08 isolate is an avian-swine-like reassortant with the PB2, PA, NP, and M genes coming from a 2006 Korean swine H3N1-like virus. The molecular characterization of the two viruses indicated an absence of significant mutations that could be associated with virulence or binding affinity. However, animal experiments showed that the reassortant Sw/Korea/C13/08 virus was more adapted and was more readily transmitted than the purely avian-like virus in a swine experimental model but not in ferrets. Furthermore, seroprevalence in swine sera from 2006 to 2008 suggested that avian H5 viruses have been infecting swine since 2006. Although there are no known potential clinical implications of the avian-swine reassortant virus for pathogenicity in pigs or other species, including humans, at present, the efficient transmissibility of the swine-adapted H5N2 virus could facilitate virus spread and could be a potential model for pandemic, highly pathogenic avian influenza (e.g., H5N1 and H7N7) virus outbreaks or a pandemic strain itself.

scholarly journals Development and application of a real-time RT-PCR assay to rapidly detect H2 subtype avian influenza A viruses

2021 ◽  
pp. 104063872199481
Author(s):  
Yixin Xiao ◽  
Fan Yang ◽  
Fumin Liu ◽  
Hangping Yao ◽  
Nanping Wu ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Real Time ◽  
Influenza A ◽  
Minor Groove Binder ◽  
Rt Pcr ◽  
Influenza A Viruses ◽  
Pcr Assay ◽  
Infectious Dose ◽  
The Matrix ◽  
Taqman Minor Groove Binder

The H2 subtypes of avian influenza A viruses (avian IAVs) have been circulating in poultry, and they have the potential to infect humans. Therefore, establishing a method to quickly detect this subtype is pivotal. We developed a TaqMan minor groove binder real-time RT-PCR assay that involved probes and primers based on conserved sequences of the matrix and hemagglutinin genes. The detection limit of this assay was as low as one 50% egg infectious dose (EID50)/mL per reaction. This assay is specific, sensitive, and rapid for detecting avian IAV H2 subtypes.

Ongoing transmission of avian influenza A viruses in Hong Kong despite very comprehensive poultry control measures: A prospective seroepidemiology study

2016 ◽  
Vol 72 (2) ◽  
pp. 207-213 ◽  
Author(s):  
Kelvin K.W. To ◽  
Ivan F.N. Hung ◽  
Yin-Ming Lui ◽  
Florence K.Y. Mok ◽  
Andy S.F. Chan ◽  
...  
Keyword(s):  
Hong Kong ◽  
Avian Influenza ◽  
Influenza A ◽  
Control Measures ◽  
Influenza A Viruses

scholarly journals Isolation and characterization of low pathogenic H9N2 avian influenza A viruses from a healthy flock and its comparison to other H9N2 isolates

2013 ◽  
Vol 24 (3) ◽  
pp. 342-348 ◽  
Author(s):  
Muhammad Munir ◽  
Siamak Zohari ◽  
Muhammad Abbas ◽  
Muhammad Zubair Shabbir ◽  
Muhammad Nauman Zahid ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza A Viruses ◽  
Isolation And Characterization

scholarly journals Characterization of a Human H5N1 Influenza A Virus Isolated in 2003

2005 ◽  
Vol 79 (15) ◽  
pp. 9926-9932 ◽  
Author(s):  
Kyoko Shinya ◽  
Masato Hatta ◽  
Shinya Yamada ◽  
Ayato Takada ◽  
Shinji Watanabe ◽  
...  
Keyword(s):  
Hong Kong ◽  
Avian Influenza ◽  
Influenza A Virus ◽  
Influenza A ◽  
Mainland China ◽  
Virus Infections ◽  
Influenza A Viruses ◽  
H5n1 Avian Influenza Virus ◽  
H5n1 Influenza ◽  
Avian Influenza A Virus

ABSTRACT In 2003, H5N1 avian influenza virus infections were diagnosed in two Hong Kong residents who had visited the Fujian province in mainland China, affording us the opportunity to characterize one of the viral isolates, A/Hong Kong/213/03 (HK213; H5N1). In contrast to H5N1 viruses isolated from humans during the 1997 outbreak in Hong Kong, HK213 retained several features of aquatic bird viruses, including the lack of a deletion in the neuraminidase stalk and the absence of additional oligosaccharide chains at the globular head of the hemagglutinin molecule. It demonstrated weak pathogenicity in mice and ferrets but caused lethal infection in chickens. The original isolate failed to produce disease in ducks but became more pathogenic after five passages. Taken together, these findings portray the HK213 isolate as an aquatic avian influenza A virus without the molecular changes associated with the replication of H5N1 avian viruses in land-based poultry such as chickens. This case challenges the view that adaptation to land-based poultry is a prerequisite for the replication of aquatic avian influenza A viruses in humans.

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

2006 ◽  
Vol 135 (3) ◽  
pp. 386-391 ◽  
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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