scholarly journals H7N9 influenza viruses interact preferentially with α2,3-linked sialic acids and bind weakly to α2,6-linked sialic acids

2013 ◽  
Vol 94 (11) ◽  
pp. 2417-2423 ◽  
Author(s):  
Irene Ramos ◽  
Florian Krammer ◽  
Rong Hai ◽  
Domingo Aguilera ◽  
Dabeiba Bernal-Rubio ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Solid Phase ◽  
Sialic Acids ◽  
Influenza Viruses ◽  
The Novel ◽  
Avian Influenza A Virus ◽  
Emerging Virus ◽  
Solid Phase Binding ◽  
Receptor Binding Specificity

The recent human outbreak of H7N9 avian influenza A virus has caused worldwide concerns. Receptor binding specificity is critical for viral pathogenicity, and still not thoroughly studied for this emerging virus. Here, we evaluated the receptor specificity of the haemagglutinin (HA) of two human H7N9 isolates (A/Shanghai/1/13 and A/Anhui/1/13) through a solid-phase binding assay and a flow cytometry-based assay. In addition, we compared it with those from several HAs from human and avian influenza viruses. We observed that the HAs from the novel H7 isolates strongly interacted with α2,3-linked sialic acids. Importantly, they also showed low levels of binding to α2,6-linked sialic acids, but significantly higher than other avian H7s.

scholarly journals Molecular Basis for the Generation in Pigs of Influenza A Viruses with Pandemic Potential

1998 ◽  
Vol 72 (9) ◽  
pp. 7367-7373 ◽  
Author(s):  
Toshihiro Ito ◽  
J. Nelson S. S. Couceiro ◽  
Sørge Kelm ◽  
Linda G. Baum ◽  
Scott Krauss ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Structural Basis ◽  
Human Populations ◽  
Influenza A Viruses ◽  
Human Virus ◽  
Surface Receptors ◽  
Virus Receptors ◽  
Avian Influenza A Virus

ABSTRACT Genetic and biologic observations suggest that pigs may serve as “mixing vessels” for the generation of human-avian influenza A virus reassortants, similar to those responsible for the 1957 and 1968 pandemics. Here we demonstrate a structural basis for this hypothesis. Cell surface receptors for both human and avian influenza viruses were identified in the pig trachea, providing a milieu conducive to viral replication and genetic reassortment. Surprisingly, with continued replication, some avian-like swine viruses acquired the ability to recognize human virus receptors, raising the possibility of their direct transmission to human populations. These findings help to explain the emergence of pandemic influenza viruses and support the need for continued surveillance of swine for viruses carrying avian virus genes.

scholarly journals Molecular Analysis of H7 Avian Influenza Viruses from Australia and New Zealand: Genetic Diversity and Relationships from 1976 to 2007

2010 ◽  
Vol 84 (19) ◽  
pp. 9957-9966 ◽  
Author(s):  
Dieter Bulach ◽  
Rebecca Halpin ◽  
David Spiro ◽  
Laura Pomeroy ◽  
Daniel Janies ◽  
...  
Keyword(s):  
New Zealand ◽  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Full Genome Sequencing ◽  
Influenza A Viruses ◽  
Independent Evolution ◽  
Avian Influenza A Virus ◽  
Geographic Regions ◽  
Genetic Pool

ABSTRACT Full-genome sequencing of 11 Australian and 1 New Zealand avian influenza A virus isolate (all subtype H7) has enabled comparison of the sequences of each of the genome segments to those of other subtype H7 avian influenza A viruses. The inference of phylogenetic relationships for each segment has been used to develop a model of the natural history of these viruses in Australia. Phylogenetic analysis of the hemagglutinin segment indicates that the Australian H7 isolates form a monophyletic clade. This pattern is consistent with the long-term, independent evolution that is, in this instance, associated with geographic regions. On the basis of the analysis of the other H7 hemagglutinin sequences, three other geographic regions for which similar monophyletic clades have been observed were confirmed. These regions are Eurasia plus Africa, North America, and South America. Analysis of the neuraminidase sequences from the H7N1, H7N3, and H7N7 genomes revealed the same region-based relationships. This pattern of independent evolution of Australian isolates is supported by the results of analysis of each of the six remaining genomic segments. These results, in conjunction with the occurrence of five different combinations of neuraminidase subtypes (H7N2, H7N3, H7N4, H7N6, H7N7) among the 11 Australian isolates, suggest that the maintenance host(s) is nearly exclusively associated with Australia. The single lineage of Australian H7 hemagglutinin sequences, despite the occurrence of multiple neuraminidase types, suggests the existence of a genetic pool from which a variety of reassortants arise rather than the presence of a small number of stable viral clones. This pattern of evolution is likely to occur in each of the regions mentioned above.

Identification of a Small Benzamide Inhibitor of Influenza Virus Using a Cell-Based Screening

Chemotherapy ◽  
2016 ◽  
Vol 61 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Woo-Jin Shin ◽  
Ky-Youb Nam ◽  
Nam-Doo Kim ◽  
Sei-Hwan Kim ◽  
Kyoung-Tai No ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
H1n1 Influenza ◽  
Influenza Viruses ◽  
Global Pandemic ◽  
Lethal Infection ◽  
Avian Influenza A Virus ◽  
A Cell ◽  
Antiviral Activities

Background: The zoonotic transmission of highly pathogenic avian influenza viruses and the global pandemic of H1N1 influenza in 2009 signified the need for a wider coverage of therapeutic options for the control of influenza. Methods: An in-house compound library was screened using a cytopathic effect inhibition assay. Selected hits were then tested in vivo and used as a core skeleton for derivative synthesis. Results: The hit compound (BMD-2601505) was effective [50% effective concentration (EC50) of 60-70 μM] in reducing the death rate of cells infected with human influenza A and B viruses as well as avian influenza A virus. Furthermore, BMD-2601505 reduced the weight loss and increased the survival after lethal infection. The compound was further modified to enhance its antiviral potency. Results show that one derivative with bromobenzene moiety was most effective (EC50 of 22-37 μM) against the influenza viruses tested. Conclusion: We identified a small benzamide compound exhibiting antiviral activity against influenza viruses. The results warrant further evaluation of antiviral activities against drug-resistant influenza isolates.

scholarly journals Newly Emergent Highly Pathogenic H5N9 Subtype Avian Influenza A Virus

2015 ◽  
Vol 89 (17) ◽  
pp. 8806-8815 ◽  
Author(s):  
Yang Yu ◽  
Xingbo Wang ◽  
Tao Jin ◽  
Hailong Wang ◽  
Weiying Si ◽  
...  
Keyword(s):  
Public Health ◽  
Avian Influenza ◽  
Influenza A ◽  
Mortality Rates ◽  
The Novel ◽  
Reassortant Virus ◽  
Highly Pathogenic ◽  
Live Bird Markets ◽  
Avian Influenza A Virus ◽  
Live Bird

ABSTRACTThe novel H7N9 avian influenza virus (AIV) was demonstrated to cause severe human respiratory infections in China. Here, we examined poultry specimens from live bird markets linked to human H7N9 infection in Hangzhou, China. Metagenomic sequencing revealed mixed subtypes (H5, H7, H9, N1, N2, and N9). Subsequently, AIV subtypes H5N9, H7N9, and H9N2 were isolated. Evolutionary analysis showed that the hemagglutinin gene of the novel H5N9 virus originated from A/Muscovy duck/Vietnam/LBM227/2012 (H5N1), which belongs to clade 2.3.2.1. The neuraminidase gene of the novel H5N9 virus originated from human-infective A/Hangzhou/1/2013 (H7N9). The six internal genes were similar to those of other H5N1, H7N9, and H9N2 virus strains. The virus harbored the PQRERRRKR/GL motif characteristic of highly pathogenic AIVs at the HA cleavage site. Receptor-binding experiments demonstrated that the virus binds α-2,3 sialic acid but not α-2,6 sialic acid. Identically, pathogenicity experiments also showed that the virus caused low mortality rates in mice. This newly isolated H5N9 virus is a highly pathogenic reassortant virus originating from H5N1, H7N9, and H9N2 subtypes. Live bird markets represent a potential transmission risk to public health and the poultry industry.IMPORTANCEThis investigation confirms that the novel H5N9 subtype avian influenza A virus is a reassortant strain originating from H5N1, H7N9, and H9N2 subtypes and is totally different from the H5N9 viruses reported before. The novel H5N9 virus acquired a highly pathogenic H5 gene and an N9 gene from human-infecting subtype H7N9 but caused low mortality rates in mice. Whether this novel H5N9 virus will cause human infections from its avian host and become a pandemic subtype is not known yet. It is therefore imperative to assess the risk of emergence of this novel reassortant virus with potential transmissibility to public health.

scholarly journals Modern application and prospects of the stable isotopes  method for studying avian influenza A virus transmission   in migratory birds

2019 ◽  
Vol 14 (3) ◽  
pp. 92-100
Author(s):  
O. R. Druzyaka ◽  
A. V. Druzyaka ◽  
M. A. Gulyaeva ◽  
F. Huettmann ◽  
A. M. Shestopalov
Keyword(s):  
Stable Isotopes ◽  
Avian Influenza ◽  
Influenza A Virus ◽  
Influenza A ◽  
Bird Migration ◽  
Migratory Birds ◽  
Influenza Viruses ◽  
Migration Routes ◽  
Viral Pathogen ◽  
Avian Influenza A Virus

Aim. The circulation and transmission of pathogens is a global biological phenomenon that is closely associated with bird migration. This analysis was carried out with  the aim of understanding and assessing the prospects of using the stable isotope  method to study the circulation and transmission of the avian influenza A virus via  migratory birds. Discussion. Insufficient data on the distances of migration of infected birds and their  interpopulational relationships leaves open the question of the transmission of highly pathogenic influenza viruses (HSV) in the wild bird population. A deeper study of  the role of migrations in the spread of HSV may possibly allow the more effective  investigation of the transmission of the viral pathogen between individuals at migration stopover sites and the clarification of global migration routes. New methodological approaches are providing a more complete picture of the geography and phenology of migrations, as well as of the consequences of migratory behavior for species biology. The study of the quantitative component of migratory flows based on  the analysis of the content of stable isotopes (SIMS) in bird tissues seems very promising. This method is being applied to the solution of various environmental issues,  including the study of animal migrations.   Conclusion. Based on data from the scientific literature, it is shown that SIMS is  promising for the clarification of bird migration routes and the quantification of their  intensity. The resolving power of the method is sufficient to determine the migration  pathways of carriers of viral pathogens on the scale of zoogeographic subdomains  and in even further detail. However, to date, there have been few such studies: in  Russia they have not been conducted at all. The increased use of the SIMS methodology may possibly reveal new ways in which viral infections are spread via birds.  

scholarly journals Generation of a Highly Pathogenic Avian Influenza A Virus from an Avirulent Field Isolate by Passaging in Chickens

2001 ◽  
Vol 75 (9) ◽  
pp. 4439-4443 ◽  
Author(s):  
Toshihiro Ito ◽  
Hideo Goto ◽  
Eiji Yamamoto ◽  
Hiroko Tanaka ◽  
Mutsuko Takeuchi ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Field Isolate ◽  
Influenza Viruses ◽  
Highly Pathogenic ◽  
Avian Influenza A Virus ◽  
Highly Virulent ◽  
Type Sequence ◽  
Wild Waterfowl ◽  
Selection Of

ABSTRACT Highly virulent avian influenza viruses can arise from avirulent strains maintained in poultry, but evidence to support their generation from viruses in wild birds is lacking. The most likely mechanism for the acquisition of virulence by benign avian viruses is the introduction of mutations by error-prone RNA polymerase, followed by the selection of virulent viruses. To investigate whether this mechanism could apply to wild waterfowl, we studied an avirulent wild-swan virus that replicates poorly in chickens. After 24 consecutive passages by air sac inoculation, followed by five passages in chicken brain, the avirulent virus became highly pathogenic in chickens, producing a 100% mortality rate. Sequence analysis at the hemmaglutinin cleavage site of the original isolate revealed a typical avirulence type of sequence, R-E-T-R, which progressed incrementally to a typical virulence type of sequence, R-R-K-K-R, during repeated passages in chickens. These results demonstrate that avirulent viruses maintained in wild waterfowl in nature and bearing the consensus avirulence type sequence R-E-T-R have the potential to become highly pathogenic while circulating in chickens.

scholarly journals In vitro demonstration of neural transmission of avian influenza A virus

2005 ◽  
Vol 86 (4) ◽  
pp. 1131-1139 ◽  
Author(s):  
Kazuya Matsuda ◽  
Takuma Shibata ◽  
Yoshihiro Sakoda ◽  
Hiroshi Kida ◽  
Takashi Kimura ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A Virus ◽  
Intermediate Filaments ◽  
Influenza A ◽  
Pseudorabies Virus ◽  
Influenza Viruses ◽  
Avian Influenza A Virus ◽  
Neural Transmission ◽  
The Central Nervous System

Neural involvement following infections of influenza viruses can be serious. The neural transport of influenza viruses from the periphery to the central nervous system has been indicated by using mouse models. However, no direct evidence for neuronal infection has been obtained in vitro and the mechanisms of neural transmission of influenza viruses have not been reported. In this study, the transneural transmission of a neurotropic influenza A virus was examined using compartmentalized cultures of neurons from mouse dorsal root ganglia, and the results were compared with those obtained using the pseudorabies virus, a virus with well-established neurotransmission. Both viruses reached the cell bodies of the neurons via the axons. This is the first report on axonal transport of influenza A virus in vitro. In addition, the role of the cytoskeleton (microtubules, microfilaments and intermediate filaments) in the neural transmission of influenza virus was investigated by conducting cytoskeletal perturbation experiments. The results indicated that the transport of avian influenza A virus in the neurons was independent of microtubule integrity but was dependent on the integrity of intermediate filaments, whereas pseudorabies virus needed both for neural spread.

scholarly journals Laboratory preparedness in EU/EEA countries for detection of novel avian influenza A(H7N9) virus, May 2013

2014 ◽  
Vol 19 (4) ◽  
Author(s):  
E Broberg ◽  
D Pereyaslov ◽  
M Struelens ◽  
D Palm ◽  
A Meijer ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Real Time ◽  
Influenza A Virus ◽  
Influenza A ◽  
Virus Detection ◽  
Influenza Viruses ◽  
World Health ◽  
Reference Laboratory ◽  
The Novel ◽  
Rt Pcr

Following human infections with novel avian influenza A(H7N9) viruses in China, the European Centre for Disease Prevention and Control, the World Health Organization (WHO) Regional Office for Europe and the European Reference Laboratory Network for Human Influenza (ERLI-Net) rapidly posted relevant information, including real-time RT-PCR protocols. An influenza RNA sequence-based computational assessment of detection capabilities for this virus was conducted in 32 national influenza reference laboratories in 29 countries, mostly WHO National Influenza Centres participating in the WHO Global Influenza Surveillance and Response System (GISRS). Twenty-seven countries considered their generic influenza A virus detection assay to be appropriate for the novel A(H7N9) viruses. Twenty-two countries reported having containment facilities suitable for its isolation and propagation. Laboratories in 27 countries had applied specific H7 real-time RT-PCR assays and 20 countries had N9 assays in place. Positive control virus RNA was provided by the WHO Collaborating Centre in London to 34 laboratories in 22 countries to allow evaluation of their assays. Performance of the generic influenza A virus detection and H7 and N9 subtyping assays was good in 24 laboratories in 19 countries. The survey showed that ERLI-Net laboratories had rapidly developed and verified good capability to detect the novel A(H7N9) influenza viruses.

scholarly journals The Impact of the Closure of the Live Poultry Market due to COVID-19 on the Avian Influenza Virus in Nanchang, Jiangxi Province, China

2021 ◽  
Author(s):  
Jin Guo ◽  
Wentao Song ◽  
Xiansheng Ni ◽  
Kun Zhou ◽  
Jingwen Wu ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Influenza Viruses ◽  
Jiangxi Province ◽  
Detection Rates ◽  
Before And After ◽  
Avian Influenza A Virus ◽  
Positive Rate ◽  
Live Poultry ◽  
The Impact

This article aims to understand the changes in the detection rates of H5, H7, and H9 subtypes of avian influenza viruses (AIVs) in the live poultry markets (LPMs) in Nanchang City, Jiangxi Province, before and after the outbreak of the COVID-19. From 2019 to 2020, we monitored the LPM and collected specimens, using real-time reverse transcription polymerase chain reaction technology to detect the nucleic acid of type A AIV in the samples. The H5, H7, and H9 subtypes of influenza viruses were further classified for positive results. We analyzed 1,959 samples before and after the outbreak and found that the positive rates of avian influenza A virus (39.69%) and H9 subtype (30.66%) after the outbreak were significantly higher than before the outbreak (26.84% and 20.90%, respectively; P < 0.001). In various LPMs, the positive rate of H9 subtypes has increased significantly (P ≤ 0.001). Positive rates of the H9 subtype in duck, fecal, daub, and sewage samples, but not chicken samples, have increased to varying degrees. This study shows that additional measures are needed to strengthen the control of AIVs now that LPMs have reopened after the relaxing of COVID-19–related restrictions.

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