H9N2 influenza viruses from birds used in falconry.
Ontology highlight
ABSTRACT:
SUBMITTER: Wernery U
PROVIDER: S-EPMC3823638 | biostudies-other | 2013 Nov
REPOSITORIES: biostudies-other
Similar Datasets
Project description:The five avian influenza A/H9N2 viruses isolated from wild birds in Jiangxi, China in 2015 are novel reassortants which most likely evolved from multiple lineages. They shared a high similarity with isolates from poultry, suggesting a frequent contact and continuous viral circulation at the bird-poultry interface. Given the continuous reassortment of H9N2 viruses, it will of substantial importance to implement routine surveillance in wild birds to successfully control avian influenza viruses and better the early warning system of the emerging reassortants with pandemic potential.
| S-EPMC8136960 | biostudies-literature
Project description:H9N2 avian influenza virus is a zoonotic agent with a broad host range that can contribute genetic information to H5 or H7N9 subtype viruses, which are significant threats to both humans and birds. Thus, there is a great need for a vaccine to control H9N2 avian influenza. Three mutant viruses of an H9N2 virus A/chicken/Taixing/10/2010 (rTX-NS1-73, rTX-NS1-100, and rTX-NS1-128) were constructed with different NS1 gene truncations and confirmed by western blot analysis. The genetic stability, pathogenicity, transmissibility, and host immune responses toward these mutants were evaluated. The mutant virus rTX-NS1-128 exhibited the most attenuated phenotype and lost transmissibility. The expression levels of interleukin 12 in the nasal and tracheal tissues from chickens immunized with rTX-NS1-128 were significantly upregulated on day 3 post-immunization and the IgA and IgG antibody levels were significantly increased on days 7, 14, and 21 post-immunization when compared to chickens that received an inactivated vaccine. rTX-NS1-128 also protected chickens from challenge by homologous and heterologous H9N2 avian influenza viruses. The results indicate that rTX-NS1-128 can be used as a potential live-attenuated vaccine against H9N2 avian influenza.
| S-EPMC5469905 | biostudies-literature
Project description:The hemagglutinins (HAs) of H9 influenza viruses isolated from birds and mammals of different species were antigenically and genetically analyzed. Antigenic variants were selected from A/swine/Hong Kong/10/98 (H9N2) and A/duck/Hokkaido/13/00 (H9N2) in the presence of monoclonal antibodies (MAbs). Based on the reactivity patterns of these mutants with a panel of MAbs, at least five non-overlapping antigenic sites were defined using eight MAbs which recognized seven distinct epitopes on the H9 HA molecule. Based on the reactivity patterns with the panel of monoclonal antibodies, 21 H9N2 virus strains isolated from birds and mammals were divided into 7 antigenically distinct groups. The present findings indicate that it is important to monitor the antigenic variation in H9 influenza viruses. The panel of MAbs in the present study, thus, should be useful for detailed antigenic analysis of the H9 HAs for epidemiological studies, the selection of vaccine strains, and diagnosis.
| S-EPMC7087127 | biostudies-literature
Project description:Avian influenza virus subtype H9N2 is endemic in commercial poultry in Tunisia. This subtype affects poultry and wild birds in Tunisia and poses a potential zoonotic risk. Tunisian H9N2 strains carry, in their hemagglutinins, the human-like marker 226 L that is most influential in avian-to-human viral transmission. For a better understanding of how ecological aspects of the H9N2 virus and its circulation in poultry, migratory birds and environment shapes the spread of the dissemination of H9N2 in Tunisia, herein, we investigate the epidemiological, evolutionary and zoonotic potential of seven H9N2 poultry isolates and sequence their whole genome. Phylogeographic and phylodymanic analysis were used to examine viral spread within and among wild birds, poultry and environment at geographical scales. Genetic evolution results showed that the eight gene sequences of Tunisian H9N2 AIV were characterized by molecular markers involved with virulence and mammalian infections. The geographical distribution of avian influenza virus appears as a network interconnecting countries in Europe, Asia, North Africa and West Africa. The spatiotemporal dynamics analysis showed that the H9N2 virus was transmitted from Tunisia to neighboring countries notably Libya and Algeria. Interestingly, this study also revealed, for the first time, that there was a virus transmission between Tunisia and Morocco. Bayesian analysis showed exchanges between H9N2 strains of Tunisia and those of the Middle Eastern countries, analysis of host traits showed that duck, wild birds and environment were ancestry related to chicken. The subtypes phylodynamic showed that PB1 segment was under multiple inter-subtype reassortment events with H10N7, H12N5, H5N2 and H6N1 and that PB2 was also a subject of inter-subtype reassortment with H10N4.
| S-EPMC10995884 | biostudies-literature
Project description:H9N2 avian influenza viruses are continuously monitored by the World Health Organization because they are endemic; they continually reassort with H5N1, H7N9 and H10N8 viruses; and they periodically cause human infections. We characterized H9N2 influenza viruses carrying internal genes from highly pathogenic H7N3 viruses, which were isolated from chickens or quail from live-bird markets in Bangladesh between 2010 and 2013. All of the H9N2 viruses used in this study carried mammalian host-specific mutations. We studied their replication kinetics in normal human bronchoepithelial cells and swine tracheal and lung explants, which exhibit many features of the mammalian airway epithelium and serve as a mammalian host model. All H9N2 viruses replicated to moderate-to-high titers in the normal human bronchoepithelial cells and swine lung explants, but replication was limited in the swine tracheal explants. In Balb/c mice, the H9N2 viruses were nonlethal, replicated to moderately high titers and the infection was confined to the lungs. In the ferret model of human influenza infection and transmission, H9N2 viruses possessing the Q226L substitution in hemagglutinin replicated well without clinical signs and spread via direct contact but not by aerosol. None of the H9N2 viruses tested were resistant to the neuraminidase inhibitors. Our study shows that the Bangladeshi H9N2 viruses have the potential to infect humans and highlights the importance of monitoring and characterizing this influenza subtype to better understand the potential risk these viruses pose to humans.
| S-EPMC4855072 | biostudies-other
Project description:Influenza A (H9N2) viruses are a genetically diverse population that infects wild and domestic avian species and mammals and contributed the internal gene segments to the A/H5N1 and A/H7N9 viruses associated with lethal human infections. Here we comprehensively assess the potential risk to mammals of a diverse panel of A/H9N2 viruses, representing the major H9N2 clades, using a combination of in vitro assays (e.g., antiviral susceptibility and virus growth in primary differentiated human airway cells) and in vivo assays (e.g., replication, transmission and/or pathogenicity of viruses in ducks, pigs, mice and ferrets). We observed that viruses isolated from humans, A/Hong Kong/1073/1999 and A/Hong Kong/33982/2009, had the highest risk potential. However, the A/swine/Hong Kong/9A-1/1998 and A/chicken/Hong Kong/G9/1997 viruses also displayed several features suggesting a fitness profile adapted to human infection and transmission. The North American avian H9N2 clade virus had the lowest risk profile, and the other viruses tested displayed various levels of fitness across individual assays. In many cases, the known genotypic polymorphisms alone were not sufficient to accurately predict the virus' phenotype. Therefore, we conclude that comprehensive risk analyses based on surveillance of circulating influenza virus strains are necessary to assess the potential for human infection by emerging influenza A viruses.
| S-EPMC3924558 | biostudies-literature
Project description:H9N2 subtype avian influenza viruses (AIVs) have been isolated from various species of wild birds and domestic poultry in the world, and occasionally transmitted to humans. Although H9N2 AIVs are seldom isolated from ostriches, seven such strains were isolated from sick ostriches in China between 2013 and 2014. Sequence analysis showed several amino acid changes relating to viral adaptation in mammals were identified. The phylogenetic analyses indicated that these isolates were quadruple reassortant viruses, which are different from the early ostrich isolates from South Africa or Israel. Most of the ostrich virus carried a human-type receptor-binding property. The chicken experiments showed the ostrich strains displayed low pathogenicity, while they could cause mild to severe symptoms in chicken. Theses strains could efficiently transmit among chickens, and one strain showed higher transmissibility. The virus could not kill mice, and merely replicated in the lung of mice. The ostrich strains could not efficiently transmit between guinea pigs in the direct contact model. These results suggested we should pay attention to the interface between ostrich and other domestic fowl, and keep an eye on this population when monitoring of influenza virus.
| S-EPMC5797180 | biostudies-literature
Project description:Human infection with avian influenza A(H9N2) virus was identified in Bangladesh in 2011. Surveillance for influenza viruses in apparently healthy poultry in live-bird markets in Bangladesh during 2008-2011 showed that subtype H9N2 viruses are isolated year-round, whereas highly pathogenic subtype H5N1 viruses are co-isolated with subtype H9N2 primarily during the winter months. Phylogenetic analysis of the subtype H9N2 viruses showed that they are reassortants possessing 3 gene segments related to subtype H7N3; the remaining gene segments were from the subtype H9N2 G1 clade. We detected no reassortment with subtype H5N1 viruses. Serologic analyses of subtype H9N2 viruses from chickens revealed antigenic conservation, whereas analyses of viruses from quail showed antigenic drift. Molecular analysis showed that multiple mammalian-specific mutations have become fixed in the subtype H9N2 viruses, including changes in the hemagglutinin, matrix, and polymerase proteins. Our results indicate that these viruses could mutate to be transmissible from birds to mammals, including humans.
| S-EPMC3810925 | biostudies-literature
Project description:In 1997, 18 cases of influenza in Hong Kong (bird flu) caused by a novel H5N1 (chicken) virus resulted in the deaths of six individuals and once again raised the specter of a potentially devastating influenza pandemic. Slaughter of the poultry in the live bird markets removed the source of infection and no further human cases of H5N1 infection have occurred. In March 1999, however, a new pandemic threat appeared when influenza A H9N2 viruses infected two children in Hong Kong. These two virus isolates are similar to an H9N2 virus isolated from a quail in Hong Kong in late 1997. Although differing in their surface hemagglutinin and neuraminidase components, a notable feature of these H9N2 viruses is that the six genes encoding the internal components of the virus are similar to those of the 1997 H5N1 human and avian isolates. This common feature emphasizes the apparent propensity of avian viruses with this genetic complement to infect humans and highlights the potential for the emergence of a novel human pathogen.
| S-EPMC16920 | biostudies-literature
Project description:Three H9N2 avian influenza viruses were isolated from the Dongting Lake wetland, among which one was from fresh egret feces, the other two were from chicken cloacal swabs in poultry markets. Phylogenetic analyses suggested that eight genes of the egret-derived H9N2 virus might come from Korean-like or American-like lineages. The two poultry-derived H9N2 viruses were reassortants between the CK/BJ/94-like and G1-like viruses. Except the PB1 genes (90.6%), the nucleotide sequence of other internal genes of the two viruses exhibited high homology (>95%). In addition, they also exhibited high homology (96-98.3%) with some genes of the H7N9 virus that caused an epidemic in China in 2013. Nucleotide sequence of the poultry-derived and egret-derived H9N2 viruses shared low homology. Infection studies showed that the egret-derived H9N2 virus was non-pathogenic to both mice and chickens, and the virus was unable to infect chickens even through 8 passages continuously in the lung. On the other hand, the chickens infected by poultry-derived viruses showed obvious clinical symptoms and even died; the infected mice showed no noticeable clinical symptoms and weight loss, but viruses could be detected in their lungs. In conclusion, for the egret-derived H9N2 virus, it would take a long adaptation process to achieve cross-species transmission in poultry and mammals. H9N2 viruses isolated at different times from the same host species in the same geographical region presented different evolutionary status, and virus isolated from different hosts in the same geographical region exhibited genetic diversity. Therefore, it is important to continue the H9N2 virus surveillance for understanding their evolutionary trends so as to provide guidance for disease control and prevention.
| S-EPMC4076334 | biostudies-literature