scholarly journals Genetic Characteristics and Pathogenicity Analysis in Chickens and Mice of Three H9N2 Avian Influenza Viruses

Viruses ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1127 ◽  
Author(s):  
Yafen Song ◽  
Yong Zhang ◽  
Ling Chen ◽  
Bing Zhang ◽  
Min Zhang ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Avian Influenza ◽  
Animal Studies ◽  
Influenza Viruses ◽  
H9n2 Virus ◽  
Post Inoculation ◽  
Avian Influenza Viruses ◽  
Genetic Characteristics ◽  
H9n2 Avian Influenza Virus ◽  
Virus Surveillance

H9N2 avian influenza is a remarkable disease that has circulated in domestic poultry in large regions of China and posed a serious threat to the poultry industry. The H9N2 virus can not only infect mammals directly, but also provide gene segments to generate novel, but lethal human reassortants. Therefore, it is important to study the evolution, pathogenicity, and transmission of the H9N2 virus. In this study, three H9N2 viruses isolated from chickens in different layer farms were identified. Phylogenetic analysis revealed that these H9N2 viruses were all multiple genotype reassortants, with genes originating from Y280-like, F/98-like, and G1-like viruses. Animal studies indicated that the AV1535 and AV1548 viruses replicated efficiently in the lungs, tracheas, spleens, kidneys, and brains of chickens; the viruses shed for at least 11 days post-inoculation (DPI) and were transmitted efficiently among contact chickens. The AV1534 virus replicated poorly in chickens, shed for 7 DPI, and were not transmitted efficiently among contact chickens. The AV1534 virus replicated well in mice lungs and caused about 2% weight loss. The AV1535 and AV1548 viruses were not able to replicate in the lungs of mice. Our results indicate that we should pay attention to H9N2 avian influenza virus surveillance in poultry and changes in the pathogenicity of them to mammals.

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

Phylogenetic analysis of avian influenza viruses of H11 subtype isolated in Kazakhstan

Virus Genes ◽  
2011 ◽  
Vol 43 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Kobey Karamendin ◽  
Aidyn Kydyrmanov ◽  
Kainar Zhumatov ◽  
Saule Asanova ◽  
Naylya Ishmukhametova ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Avian Influenza ◽  
Influenza Viruses ◽  
Avian Influenza Viruses

scholarly journals Contribution of Segment 3 to the Acquisition of Virulence in Contemporary H9N2 Avian Influenza Viruses

2020 ◽  
Vol 94 (20) ◽  
Author(s):  
Anabel L. Clements ◽  
Joshua E. Sealy ◽  
Thomas P. Peacock ◽  
Jean-Remy Sadeyen ◽  
Saira Hussain ◽  
...  
Keyword(s):  
Middle East ◽  
Avian Influenza ◽  
Mortality Rates ◽  
Influenza Viruses ◽  
H9n2 Virus ◽  
Morbidity And Mortality ◽  
Single Amino Acid ◽  
Economic Damage ◽  
Poultry Production ◽  
Avian Influenza Viruses

ABSTRACT H9N2 avian influenza viruses (AIVs) circulate in poultry throughout much of Asia, the Middle East, and Africa. These viruses cause huge economic damage to poultry production systems and pose a zoonotic threat both in their own right and in the generation of novel zoonotic viruses, for example, H7N9. In recent years, it has been observed that H9N2 viruses have further adapted to gallinaceous poultry, becoming more highly transmissible and causing higher morbidity and mortality. Here, we investigate the molecular basis for this increased virulence, comparing a virus from the 1990s and a contemporary field strain. The modern virus replicated to higher titers in various systems, and this difference mapped to a single amino acid polymorphism at position 26 of the endonuclease domain shared by the PA and PA-X proteins. This change was responsible for increased replication and higher morbidity and mortality rates along with extended tissue tropism seen in chickens. Although the PA K26E change correlated with increased host cell shutoff activity of the PA-X protein in vitro, it could not be overridden by frameshift site mutations that block PA-X expression and therefore increased PA-X activity could not explain the differences in replication phenotype. Instead, this indicates that these differences are due to subtle effects on PA function. This work gives insight into the ongoing evolution and poultry adaptation of H9N2 and other avian influenza viruses and helps us understand the striking morbidity and mortality rates in the field, as well as the rapidly expanding geographical range seen in these viruses. IMPORTANCE Avian influenza viruses, such as H9N2, cause huge economic damage to poultry production worldwide and are additionally considered potential pandemic threats. Understanding how these viruses evolve in their natural hosts is key to effective control strategies. In the Middle East and South Asia, an older H9N2 virus strain has been replaced by a new reassortant strain with greater fitness. Here, we take representative viruses and investigate the genetic basis for this “fitness.” A single mutation in the virus was responsible for greater fitness, enabling high growth of the contemporary H9N2 virus in cells, as well as in chickens. The genetic mutation that modulates this change is within the viral PA protein, a part of the virus polymerase gene that contributes to viral replication as well as to virus accessory functions—however, we find that the fitness effect is specifically due to changes in the protein polymerase activity.

scholarly journals The PB2 and M genes of genotype S H9N2 virus contribute to the enhanced fitness of H5Nx and H7N9 avian influenza viruses in chickens

Virology ◽  
2019 ◽  
Vol 535 ◽  
pp. 218-226 ◽  
Author(s):  
Xiaoli Hao ◽  
Xiaoquan Wang ◽  
Jiao Hu ◽  
Min Gu ◽  
Jiongjiong Wang ◽  
...  
Keyword(s):  
Avian Influenza ◽  
Influenza Viruses ◽  
H9n2 Virus ◽  
Avian Influenza Viruses

scholarly journals A Global Perspective on H9N2 Avian Influenza Virus

Viruses ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 620 ◽  
Author(s):  
T(homas). P. Peacock ◽  
Joe James ◽  
Joshua E. Sealy ◽  
Munir Iqbal
Keyword(s):  
Influenza Virus ◽  
Avian Influenza ◽  
Avian Influenza Virus ◽  
Host Range ◽  
Influenza Viruses ◽  
Global Perspective ◽  
Zoonotic Infection ◽  
Avian Influenza Viruses ◽  
H9n2 Avian Influenza Virus ◽  
Global Spread

H9N2 avian influenza viruses have become globally widespread in poultry over the last two decades and represent a genuine threat both to the global poultry industry but also humans through their high rates of zoonotic infection and pandemic potential. H9N2 viruses are generally hyperendemic in affected countries and have been found in poultry in many new regions in recent years. In this review, we examine the current global spread of H9N2 avian influenza viruses as well as their host range, tropism, transmission routes and the risk posed by these viruses to human health.

Sign in / Sign up

Export Citation Format

Share Document