scholarly journals The Origin of Human-infecting Avian Influenza A H6N1 Virus

2013 ◽  
Author(s):  
Liangsheng Zhang ◽  
Zhenguo Zhang
Keyword(s):  
Phylogenetic Analysis ◽  
Avian Influenza ◽  
Influenza A ◽  
Human Infection ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Know How

In this study, we retraced the origin of the reported avian influenza A H6N1 virus infecting a 20-year-old woman in Taiwan. As we know, this is the first reported case of human infection by the H6N1 virus, because this subtype virus usually circulates in birds and poultry. Therefore it is crucial to know how this virus attained the ability to infect humans. Using phylogenetic analysis, we found that this virus was derived from reassortments of multiple lineages of H6N1 viruses and H5N2 viruses. The results deepen our understanding of how the new human-infecting virus originated and based on these we discussed possible explanations for the H6N1 infection of humans. Our results, together with recent studies of H7N9 viruses which result in severe disorders, suggest that reassortments among avian-type viruses are quite often, which may sometimes result in fatal infections in humans. Thus a close watch on the circulation of avian influenza viruses is pretty necessary.

scholarly journals Zoonotic Potential of Currently Circulating Avian Influenza Viruses

2020 ◽  
Vol 39 (1) ◽  
pp. 8-14
Author(s):  
Vladimir Savić
Keyword(s):  
Avian Influenza ◽  
Influenza A ◽  
Human Infection ◽  
Influenza Viruses ◽  
Influenza A Viruses ◽  
Avian Influenza Viruses ◽  
Influenza Pandemics ◽  
Human Infections ◽  
Virus Adaptation ◽  
Efficient Transmission

Over the past and the current centuries, human influenza pandemics have been attributable to viruses with an avian ancestry. Birds are the main source of influenza A viruses and harbour a variety of antigenic subtypes. Certain avian influenza viruses are capable for cross-species transmission including human infections. Although sustained intrehuman transmission of such viruses has not been documented so far, each human infection with avian influenza viruses provides chances for the virus adaptation towards efficient transmission within human population. Here are reviewed currently circulating avian influenza viruses that are of major significance for public health.

Phylogenetic analysis of hemagglutinin genes of 40 H9N2 subtype avian influenza viruses isolated from poultry in China from 2010 to 2011

Virus Genes ◽  
2012 ◽  
Vol 45 (1) ◽  
pp. 69-75 ◽  
Author(s):  
Feng Chen ◽  
Zhuan-Qiang Yan ◽  
Jun Liu ◽  
Jun Ji ◽  
Shuang Chang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Avian Influenza ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
H9n2 Subtype

scholarly journals Vaccination with Consensus H7 Elicits Broadly Reactive and Protective Antibodies against Eurasian and North American Lineage H7 Viruses

Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 143
Author(s):  
Gendeal M. Fadlallah ◽  
Fuying Ma ◽  
Zherui Zhang ◽  
Mengchan Hao ◽  
Juefu Hu ◽  
...  
Keyword(s):  
Avian Influenza ◽  
North American ◽  
Human Infection ◽  
Influenza Viruses ◽  
Avian Influenza Viruses ◽  
Lethal Challenge ◽  
Protective Antibodies ◽  
H7 Subtype ◽  
H7n3 Virus

H7 subtype avian influenza viruses have caused outbreaks in poultry, and even human infection, for decades in both Eurasia and North America. Although effective vaccines offer the best protection against avian influenza viruses, antigenically distinct Eurasian and North American lineage subtype H7 viruses require the development of cross-protective vaccine candidates. In this study, a methodology called computationally optimized broadly reactive antigen (COBRA) was used to develop four consensus H7 antigens (CH7-22, CH7-24, CH7-26, and CH7-28). In vitro experiments confirmed the binding of monoclonal antibodies to the head and stem domains of cell surface-expressed consensus HAs, indicating display of their antigenicity. Immunization with DNA vaccines encoding the four antigens was evaluated in a mouse model. Broadly reactive antibodies against H7 viruses from Eurasian and North American lineages were elicited and detected by binding, inhibition, and neutralizing analyses. Further infection with Eurasian H7N9 and North American H7N3 virus strains confirmed that CH7-22 and CH7-24 conferred the most effective protection against hetero-lethal challenge. Our data showed that the consensus H7 vaccines elicit a broadly reactive, protective response against Eurasian and North American lineage H7 viruses, which are suitable for development against other zoonotic influenza viruses.

scholarly journals Development of a duplex TaqMan real-time RT-PCR assay for simultaneous detection of newly emerged H5N6 influenza viruses

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Lin Liu ◽  
Ying Zhang ◽  
Pengfei Cui ◽  
Congcong Wang ◽  
Xianying Zeng ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Simultaneous Detection ◽  
Reaction System ◽  
Taxonomic Status ◽  
Human Infection ◽  
Influenza Viruses ◽  
Rt Pcr ◽  
Avian Influenza Viruses ◽  
Pcr Assay

Abstract Background In 2017–2018, a new highly pathogenic H5N6 avian influenza virus (AIV) variant appeared in poultry and wild birds in Asian and European countries and caused multiple outbreaks. These variant strains are different from the H5N6 virus associated with human infection in previous years, and their genetic taxonomic status and antigenicity have changed. Therefore, revision of the primers and probes of fluorescent RT-PCR is important to detect the new H5N6 subtype AIV in poultry and reduce the risk of an epidemic in birds or humans. Methods In this study, the primers and probes including three groups of HA and four groups of NA for H5N6 influenza virus were evaluated. Then a set of ideal primer and probes were selected to further optimize the reaction system and established a method of double rRT-PCR assay. The specificity of this method was determined by using H1~H16 subtype AIV. Results The results showed that fluorescence signals were obtained for H5 virus in FAM channel and N6 virus in VIC channel, and no fluorescent signal was observed in other subtypes of avian influenza viruses. The detection limit of this assay was 69 copies for H5 and 83 copies for N6 gene. And, the variability tests of intra- and inter-assay showed excellent reproducibility. Moreover, this assay showed 100% agreement with virus isolation method in detecting samples from poultry. Conclusion The duplex rRT-PCR assay presented here has high specificity, sensitivity and reproducibility, and can be used for laboratory surveillance and rapid diagnosis of newly emerged H5N6 subtype avian influenza viruses.

scholarly journals Structural and Molecular Characterization of the Hemagglutinin from the Fifth-Epidemic-Wave A(H7N9) Influenza Viruses

2018 ◽  
Vol 92 (16) ◽  
Author(s):  
Hua Yang ◽  
Paul J. Carney ◽  
Jessie C. Chang ◽  
Zhu Guo ◽  
James Stevens
Keyword(s):  
Public Health ◽  
Avian Influenza ◽  
Influenza A ◽  
Human Infection ◽  
Influenza Viruses ◽  
Surface Proteins ◽  
Health Concern ◽  
Public Health Concern ◽  
H7n9 Influenza ◽  
Epidemic Wave

ABSTRACTThe avian influenza A(H7N9) virus continues to cause human infections in China and is a major ongoing public health concern. Five epidemic waves of A(H7N9) infection have occurred since 2013, and the recent fifth epidemic wave saw the emergence of two distinct lineages with elevated numbers of human infection cases and broader geographic distribution of viral diseases compared to the first four epidemic waves. Moreover, highly pathogenic avian influenza (HPAI) A(H7N9) viruses were also isolated during the fifth epidemic wave. Here, we present a detailed structural and biochemical analysis of the surface hemagglutinin (HA) antigen from viruses isolated during this recent epidemic wave. Results highlight that, compared to the 2013 virus HAs, the fifth-wave virus HAs remained a weak binder to human glycan receptor analogs. We also studied three mutations, V177K-K184T-G219S, that were recently reported to switch a 2013 A(H7N9) HA to human-type receptor specificity. Our results indicate that these mutations could also switch the H7 HA receptor preference to a predominantly human binding specificity for both fifth-wave H7 HAs analyzed in this study.IMPORTANCEThe A(H7N9) viruses circulating in China are of great public health concern. Here, we report a molecular and structural study of the major surface proteins from several recent A(H7N9) influenza viruses. Our results improve the understanding of these evolving viruses and provide important information on their receptor preference that is central to ongoing pandemic risk assessment.

scholarly journals The Polymerase Acidic Protein Gene of Influenza A Virus Contributes to Pathogenicity in a Mouse Model

2009 ◽  
Vol 83 (23) ◽  
pp. 12325-12335 ◽  
Author(s):  
Min-Suk Song ◽  
Philippe Noriel Q. Pascua ◽  
Jun Han Lee ◽  
Yun Hee Baek ◽  
Ok-Jun Lee ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Mammalian Cells ◽  
Influenza A ◽  
Lethal Dose ◽  
Influenza Viruses ◽  
Mammalian Host ◽  
Viral Gene ◽  
Avian Influenza Viruses ◽  
Range Restriction ◽  
Viral Genes

ABSTRACT Adaptation of influenza A viruses to a new host species usually involves the mutation of one or more of the eight viral gene segments, and the molecular basis for host range restriction is still poorly understood. To investigate the molecular changes that occur during adaptation of a low-pathogenic avian influenza virus subtype commonly isolated from migratory birds to a mammalian host, we serially passaged the avirulent wild-bird H5N2 strain A/Aquatic bird/Korea/W81/05 (W81) in the lungs of mice. The resulting mouse-adapted strain (ma81) was highly virulent (50% mouse lethal dose = 2.6 log10 50% tissue culture infective dose) and highly lethal. Nonconserved mutations were observed in six viral genes (those for PB2, PB1, PA, HA, NA, and M). Reverse genetic experiments substituting viral genes and mutations demonstrated that the PA gene was a determinant of the enhanced virulence in mice and that a Thr-to-Iso substitution at position 97 of PA played a key role. In growth kinetics studies, ma81 showed enhanced replication in mammalian but not avian cell lines; the PA97I mutation in strain W81 increased its replicative fitness in mice but not in chickens. The high virulence associated with the PA97I mutation in mice corresponded to considerably enhanced polymerase activity in mammalian cells. Furthermore, this characteristic mutation is not conserved among avian influenza viruses but is prevalent among mouse-adapted strains, indicating a host-dependent mutation. To our knowledge, this is the first study that the isoleucine residue at position 97 in PA plays a key role in enhanced virulence in mice and is implicated in the adaptation of avian influenza viruses to mammalian hosts.

Sign in / Sign up

Export Citation Format

Share Document