First outbreaks and phylogenetic analyses of avian influenza H9N2 viruses isolated from poultry flocks in Morocco.

PubMed

El Houadfi, Mohammed; Fellahi, Siham; Nassik, Saadia; Guérin, Jean-Luc; Ducatez, Mariette F

2016-08-15

H9N2 avian influenza viruses continue to spread in poultry and wild birds worldwide. Morocco just faced its first H9N2 influenza virus outbreaks early 2016 affecting different types of poultry production. After its introduction, the virus spread very rapidly throughout the country. Samples were collected from 11 chicken flocks with high morbidity and mortality rates. Four viruses were successfully isolated from broiler chickens and one from broiler breeders and fully sequenced. Phylogenetic and molecular markers analyses showed the Moroccan viruses belonged to the G1 lineage and likely originated from the Middle East. As known for H9N2 viruses, the Moroccanisolates possess several genetic markers that enhance virulence in poultry and transmission to humans. The present study demonstrated that under field conditions H9N2 could have a devastating effect on egg production and mortalities and highlighted a lack of surveillance data on the pathogen in the region.

Biological Characteristics of H9N2 Avian Influenza Viruses from Healthy Chickens in Shanghai, China.

PubMed

Shi, Qingfeng; Wang, Qianli; Ju, Liwen; Xiong, Haiyan; Chen, Yue; Jiang, Lufang; Jiang, Qingwu

2016-12-10

BACKGROUND H9N2 avian influenza viruses that circulate in domestic poultry in eastern China pose challenges to human health. However, few studies have compared the biological characteristics of H9N2 viruses isolated from healthy chickens in Shanghai. MATERIAL AND METHODS Three H9N2 viruses - CK/SH/Y1/07, CK/SH/Y1/02, and CK/SH/23/13 - isolated from healthy chickens in Shanghai between 2002 and 2013, were selected and their biological characteristics were determined. RESULTS All 3 H9N2 viruses showed a preference for both the avian- and human-like receptors, and they replicated well in MDCK and A549 cells. All H9N2 viruses were non-pathogenic to mini-pigs and were detected in the trachea and lung tissues. The CK/SH/Y1/07 and CK/SH/Y1/02 viruses were transmitted to mini-pigs through direct-contact or respiratory droplet exposure, but CK/SH/23/13 virus was not. CONCLUSIONS These results suggest that H9N2 viruses isolated from healthy chickens in Shanghai efficiently replicate and transmit among pigs and other mammals.

Genetic evolution of influenza H9N2 viruses isolated from various hosts in China from 1994 to 2013

PubMed Central

Li, Chong; Wang, Shuoguo; Bing, Guoxia; Carter, Robert A; Wang, Zejiang; Wang, Jinliang; Wang, Chenxi; Wang, Lan; Wu, Gang; Webster, Robert G; Wang, Yongqiang; Sun, Honglei; Sun, Yipeng; Liu, Jinhua; Pu, Juan

2017-01-01

Influenza H9N2 subtype viruses and their reassortants (such as H7N9) are posing increasing threats to birds and humans in China. During 2009–2013, multiple novel subtype viruses with H9N2 original genes emerged in China. Yet, the genetic evolution of H9N2 viruses in various host organisms in China has not been systematically investigated since 2009. In the present study, we performed large-scale sequence analysis of H9N2 viral genomes from public databases, representing the spectrum of viruses isolated from birds, mammals and humans in China from 1994 to 2013, and updated the clade classification for each segment. We identified 117 distinct genotypes in 730 H9N2 viruses. We analyzed the sequences of all eight segments in each virus and found three important time points: the years 2000, 2006 and 2010. In the periods divided by these years, genotypic diversity, geographic distribution and host range changed considerably. Genotypic diversity fluctuated greatly in 2000 and 2006. Since 2010, a single genotype became predominant in poultry throughout China, and the eastern coastal region became the newly identified epidemic center. Throughout their 20-year prevalence in China, H9N2 influenza viruses have emerged and adapted from aquatic birds to chickens. The minor avian species and wild birds exacerbated H9N2 genotypes by providing diversified genes, and chickens were the most prevalent vector in which the viruses evolved and expanded their prevalence. It is the necessity for surveillance and disease control on live-bird markets, poultry farms and wild-bird habitats in China. PMID:29184157

Genetic evolution of influenza H9N2 viruses isolated from various hosts in China from 1994 to 2013.

PubMed

Li, Chong; Wang, Shuoguo; Bing, Guoxia; Carter, Robert A; Wang, Zejiang; Wang, Jinliang; Wang, Chenxi; Wang, Lan; Wu, Gang; Webster, Robert G; Wang, Yongqiang; Sun, Honglei; Sun, Yipeng; Liu, Jinhua; Pu, Juan

2017-11-29

Influenza H9N2 subtype viruses and their reassortants (such as H7N9) are posing increasing threats to birds and humans in China. During 2009-2013, multiple novel subtype viruses with H9N2 original genes emerged in China. Yet, the genetic evolution of H9N2 viruses in various host organisms in China has not been systematically investigated since 2009. In the present study, we performed large-scale sequence analysis of H9N2 viral genomes from public databases, representing the spectrum of viruses isolated from birds, mammals and humans in China from 1994 to 2013, and updated the clade classification for each segment. We identified 117 distinct genotypes in 730 H9N2 viruses. We analyzed the sequences of all eight segments in each virus and found three important time points: the years 2000, 2006 and 2010. In the periods divided by these years, genotypic diversity, geographic distribution and host range changed considerably. Genotypic diversity fluctuated greatly in 2000 and 2006. Since 2010, a single genotype became predominant in poultry throughout China, and the eastern coastal region became the newly identified epidemic center. Throughout their 20-year prevalence in China, H9N2 influenza viruses have emerged and adapted from aquatic birds to chickens. The minor avian species and wild birds exacerbated H9N2 genotypes by providing diversified genes, and chickens were the most prevalent vector in which the viruses evolved and expanded their prevalence. It is the necessity for surveillance and disease control on live-bird markets, poultry farms and wild-bird habitats in China.

Isolation and phylogenetic characterization of haemagglutinin and neuraminidase genes of H9N2 low pathogenicity avian influenza virus isolated from commercial layers in India.

PubMed

Gowthaman, Vasudevan; Singh, Shambu Dayal; Dhama, Kuldeep; Srinivasan, Palani; Saravanan, Sellappan; Murthy, Thippichettypalayam Ramasamy Gopala Krishna; Sukumar, Kuppanan; Mathapati, Basavaraj; Lebarbenchon, Camille; Malik, Yashpal Singh; Ramakrishnan, Muthannan Andavar

2016-12-01

Avian influenza is a highly infectious and dynamically evolving disease of birds causing high morbidity and mortality. It is caused by avian influenza virus (AIV) that belongs to the family Orthomyxoviridae. Two types of AIV have been described based on their pathogenicity viz. highly pathogenic avian influenza virus that causes severe disease with high mortality and low pathogenic avian influenza virus (LPAI) that generally causes asymptomatic infection or a mild disease. The H9N2 subtype is the widely circulated LPAI type in the world. The H9N2 subtype of was first reported from northern India in March 2003. However, systematical surveillance information for the evolution of H9N2 viruses in poultry flocks of Southern India is lacking. The present study reports the isolation and characterization of H9N2 isolates from the southern parts of the country during the period between May 2010 and September 2011. Out of the 30 poultry flocks investigated, six were found to be positive for HA activity. Further, all the six samples conformed as AIV. Partial nucleotide sequencing of the HA and NA genes revealed that all were belonging to the H9N2 subtype. Phylogenetically, the HA and NA genes of the H9N2 viruses from India clustered with those isolated from Bangladesh, Pakistan and the Middle East, although we were not able to conclude on their exact geographic origin.

Isolation and phylogenetic analysis of hemagglutinin gene of H9N2 influenza viruses from chickens in South China from 2012 to 2013.

PubMed

Shen, Han-Qin; Yan, Zhuan-Qiang; Zeng, Fan-Gui; Liao, Chang-Tao; Zhou, Qing-Feng; Qin, Jian-Ping; Xie, Qing-Mei; Bi, Ying-Zuo; Chen, Feng

2015-01-01

As part of our ongoing influenza surveillance program in South China, 19 field strains of H9N2 subtype avian influenza viruses (AIVs) were isolated from dead or diseased chicken flocks in Guangdong province, South China, between 2012 and 2013. Hemagglutinin (HA) genes of these strains were sequenced and analyzed and phylogenic analysis showed that 12 of the 19 isolates belonged to the lineage h9.4.2.5, while the other seven belonged to h9.4.2.6. Specifically, we found that all of the viruses isolated in 2013 belonged to lineage h9.4.2.5. The lineage h9.4.2.5 viruses contained a PSRSSR↓GLF motif at HA cleavage site, while the lineage h9.4.2.6 viruses contained a PARSSR↓GLF at the same position. Most of the isolates in lineage h9.4.2.5 lost one potential glycosylation site at residues 200-202, and had an additional one at residues 295-297 in HA1. Notably, 19 isolates had an amino acid exchange (Q226L) in the receptor binding site, which indicated that the viruses had potential affinity of binding to human like receptor. The present study shows the importance of continuing surveillance of new H9N2 strains to better prepare for the next epidemic or pandemic outbreak of H9N2 AIV infections in chicken flocks.

Characterization of an Avian Influenza Virus H9N2 Strain Isolated from Dove in Southern China.

PubMed

Li, Dan; Li, ZhengTing; Xie, Zhixun; Li, Meng; Xie, Zhiqin; Liu, Jiabo; Xie, Liji; Deng, Xianwen; Luo, Sisi

2018-05-03

We report here the complete genome sequence of strain H9N2, an avian influenza virus (AIV) isolated from dove in Guangxi, China. Phylogenetic analysis showed that it was a novel reassortant AIV derived from chicken, duck, and wild bird. This finding provides useful information for understanding the H9N2 subtype of AIV circulating in southern China. Copyright © 2018 Li et al.

Characterization of Influenza A (H7N9) Viruses Isolated from Human Cases Imported into Taiwan

PubMed Central

Yang, Ji-Rong; Kuo, Chuan-Yi; Huang, Hsiang-Yi; Wu, Fu-Ting; Huang, Yi-Lung; Cheng, Chieh-Yu; Su, Yu-Ting; Wu, Ho-Sheng; Liu, Ming-Tsan

2015-01-01

A novel avian influenza A (H7N9) virus causes severe human infections and was first identified in March 2013 in China. The H7N9 virus has exhibited two epidemiological peaks of infection, occurring in week 15 of 2013 and week 5 of 2014. Taiwan, which is geographically adjacent to China, faces a large risk of being affected by this virus. Through extensive surveillance, launched in April 2013, four laboratory-confirmed H7N9 cases imported from China have been identified in Taiwan. The H7N9 virus isolated from imported case 1 in May 2013 (during the first wave) was found to be closest genetically to a virus from wild birds and differed from the prototype virus, A/Anhui/1/2013, in the MP gene. The other three imported cases were detected in December 2013 and April 2014 (during the second wave). The viruses isolated from cases 2 and 4 were similar in the compositions of their 6 internal genes and distinct from A/Anhui/1/2013 in the PB2 and MP genes, whereas the virus isolated from case 3 exhibited a novel reassortment that has not been identified previously and was different from A/Anhui/1/2013 in the PB2, PA and MP genes. The four imported H7N9 viruses share similar antigenicity with A/Anhui/1/2013, and their HA and NA genes grouped together in their respective phylogenies. In contrast with the HA and NA genes, which exhibited a smaller degree of diversity, the internal genes were heterogeneous and provided potential distinctions between transmission sources in terms of both geography and hosts. It is important to strengthen surveillance of influenza and to share viral genetic data in real-time for reducing the threat of rapid and continuing evolution of H7N9 viruses. PMID:25748033

Genotypic evolution and antigenicity of H9N2 influenza viruses in Shanghai, China.

PubMed

Ge, Feifei; Li, Xin; Ju, Houbin; Yang, Dequan; Liu, Jian; Qi, Xinyong; Wang, Jian; Yang, Xianchao; Qiu, Yafeng; Liu, Peihong; Zhou, Jinping

2016-06-01

H9N2 influenza viruses have been circulating in China since 1994, but a systematic investigation of H9N2 in Shanghai has not previously been undertaken. Here, using 14 viruses we isolated from poultry and pigs in Shanghai during 2002 and 2006-2014, together with the commercial vaccine A/chicken/Shanghai/F/1998 (Ck/SH/F/98), we analyzed the evolution of H9N2 influenza viruses in Shanghai and showed that all 14 isolates originated from Ck/SH/F/98 antigenically. We evaluated the immune protection efficiency of the vaccine. Our findings demonstrate that H9N2 viruses in Shanghai have undergone extensive reassortment. Various genotypes emerged in 2002, 2006 and 2007, while during 2009-2014 only one genotype was found. Four antigenic groups, A-D, could be identified among the 14 isolates and a variety of antigenically distinct H9N2-virus-derived avian influenza viruses (AIVs) circulated simultaneously in Shanghai during this period. Challenge experiments using vaccinated chickens indicated that the vaccine prevented shedding of antigenic group A and B viruses, but not those of the more recent groups C and D. Genetic analysis showed that compared to the vaccine strain, representative viruses of antigenic groups C and D possess greater numbers of amino acid substitutions in the hemagglutinin (HA) protein than viruses in antigenic groups A and B. Many of these substitutions are located in antigenic sites. Our results indicate that the persistence of H9N2 AIV in China might be due to incomplete vaccine protection and that the avian influenza vaccine should be regularly evaluated and updated to maintain optimal protection.

Partial heterologous protection by low pathogenic H9N2 virus against natural H9N2-PB1 gene reassortant highly pathogenic H5N1 virus in chickens.

PubMed

Dash, Sandeep Kumar; Kumar, Manoj; Kataria, Jag Mohan; Nagarajan, Shanmugasundaram; Tosh, Chakradhar; Murugkar, Harshad V; Kulkarni, Diwakar D

2016-06-01

Low pathogenic avian influenza H9N2 and highly pathogenic avian influenza H5N1 viruses continue to co-circulate in chickens. Prior infection with low pathogenic avian influenza can modulate the outcome of H5N1 infection. In India, low pathogenic H9N2 and highly pathogenic H5N1 avian influenza viruses are co-circulating in poultry. Herein, by using chickens with prior infection of A/chicken/India/04TI05/2012 (H9N2) virus we explored the outcome of infection with H5N1 virus A/turkey/India/10CA03/2012 natural PB1 gene reassortant from H9N2. Four groups (E1-E4) of SPF chickens (n = 6) prior inoculated with 10(6) EID50 of H9N2 virus were challenged with 10(6) EID50 of H5N1 natural reassortant (PB1-H9N2) virus at days 1 (group E1); 3 (group E2); 7 (group E3) and 14 (group E4) post H9N2 inoculation. The survival percentage in groups E1-E4 was 0, 100, 66.6 and 50%, respectively. Virus shedding periods for groups E1-E4 were 3, 4, 7 and 9 days, respectively post H5N1 challenge. Birds of group E1 and E2 were shedding both H9N2 and H5N1 viruses and mean viral RNA copy number was higher in oropharyngeal swabs than cloacal swabs. In group, E3 and E4 birds excreted only H5N1 virus and mean viral RNA copy number was higher in most cloacal swabs than oral swabs. These results indicate that prior infection with H9N2 virus could protect from lethal challenge of reassortant H5N1 virus as early as with three days prior H9N2 inoculation and protection decreased in groups E3 and E4 as time elapsed. However, prior infection with H9N2 did not prevent infection with H5N1 virus and birds continue to excrete virus in oropharyngeal and cloacal swabs. Amino acid substitution K368E was found in HA gene of excreted H5N1 virus of group E3. Hence, concurrent infection can also cause emergence of viruses with mutations leading to virus evolution. The results of this study are important for the surveillance and epidemiological data analysis where both H9N2 and H5N1 viruses are co

Vertical Transmission of H9N2 Avian Influenza Virus in Goose.

PubMed

Yu, Guanliu; Wang, Aihua; Tang, Yi; Diao, Youxiang

2017-01-01

During a study on high mortality cases of goose embryo in Shandong Province, China (2014-2015), we isolated an H9N2 avian influenza virus (AIV) strain (A/goose/Shandong/DP01/2014, DP01), which was supposedly the causative agent for goose embryo death. Sequence analysis revealed that DP01 shared 99.9% homology in the HA gene with a classic immune suppression strain SD06. To study the potential vertical transmission ability of the DP01 strain in breeder goose, a total of 105 Taizhou breeder geese, which were 360 days old, were equally divided into five groups (A, B, C, D, and E) for experimental infection. H9N2 AIV (DP01) was used for inoculating through intravenous (group A), intranasal instillation (group B), and throat inoculation (group C) routes, respectively. The geese in group D were inoculated with phosphate buffer solution (PBS) and those in group E were the non-treated group. At 24 h post inoculation, H9N2 viral RNA could be detected at vitelline membrane, embryos, and allantoic fluid of goose embryos from H9N2 inoculated groups. Furthermore, the HA gene of H9N2 virus from vitelline membrane, embryo, allantoic fluid, and gosling shared almost 100% homology with an H9N2 virus isolated from the ovary of breeder goose, which laid these eggs, indicating that H9N2 AIV can be vertically transmitted in goose. The present research study provides evidence that vertical transmission of H9N2 AIV from breeding goose to goslings is possible.

Phylogenetic Analysis and Pathogenicity Assessment of Two Strains of Avian Influenza Virus Subtype H9N2 Isolated from Migratory Birds: High Homology of Internal Genes with Human H10N8 Virus.

PubMed

Ye, Ge; Liang, Chai Hong; Hua, Deng Guo; Song, Lei Yong; Xiang, Yang Guo; Guang, Chen; Lan, Chen Hua; Ping, Hua Yu

2016-01-01

Two human-infecting avian influenza viruses (AIVs), H7N9 and H10N8, have emerged in China, which further indicate that the H9N2 subtype of AIVs, as an internal gene donor, may have an important role in the generation of new viruses with cross-species transmissibility and pathogenicity. H9N2 viruses that contain such internal genes widely exist in poultry but are rarely reported in migratory birds. In this study, two strains of the H9N2 virus were isolated from fecal samples of migratory birds in 2014: one strain from Caizi Lake in Anhui Province and one from Chen Lake in Hubei Province of China. Nucleotide sequence analysis revealed high homology of all six internal genes of these two strains with the internal genes of the human H10N8 virus in Jiangxi Province, as well as with the human H7N9 virus. Phylogenetic analysis indicated a possible origin of these two strains from poultry in South China. Both of the two viruses tested could replicated in respiratory organs of infective mice without adaption, by both strains of the H9N2 AIVs from wild birds, suggesting their potential capacity for directly infecting mammals. Our findings indicate the existence of H9N2 viruses that contain internal genes highly homologous with human H10N8 or H7N9 viruses. Wild birds can contribute to the spread of the H9N2 virus that contains the "harmful" internal gene complex, leading to gene rearrangement with other influenza viruses and to the generation of new pathogenic viruses. Therefore, strengthening AIV surveillance in wild birds can promote an understanding of the presence and prevalence of viruses and provide scientific evidence for the prevention and control of AIVs and human-infecting AIVs.

The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals

PubMed Central

Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-01-01

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. PMID:27094903

The replication of Bangladeshi H9N2 avian influenza viruses carrying genes from H7N3 in mammals.

PubMed

Shanmuganatham, Karthik K; Jones, Jeremy C; Marathe, Bindumadhav M; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Turner, Jasmine; Rabiul Alam, S M; Kamrul Hasan, M; Akhtar, Sharmin; Seiler, Patrick; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-04-20

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.

Phylogenetic Analysis of Hemagglutinin Genes of H9N2 Avian Influenza Viruses Isolated from Chickens in Shandong, China, between 1998 and 2013.

PubMed

Zhao, Yuxin; Li, Song; Zhou, Yufa; Song, Wengang; Tang, Yujing; Pang, Quanhai; Miao, Zengmin

2015-01-01

Since H9N2 avian influenza virus (AIV) was first isolated in Guangdong province of China, the virus has been circulating in chicken flocks in mainland China. However, a systematic phylogenetic analysis of H9N2 AIV from chickens in Shandong of China has not been conducted. Based on hemagglutinin (HA) gene sequences of H9N2 AIVs isolated from chickens in Shandong of China between 1998 and 2013, genetic evolution of 35 HA gene sequences was systematically analyzed in this study. Our findings showed that the majority of H9N2 AIVs (21 out of 35) belonged to the lineage h9.4.2.5. Most of isolates (33 out of 35) had a PSRSSR↓GLF motif in HA cleavage site. Importantly, 29 out of these 35 isolates had an amino acid exchange (Q226L) in the receptor-binding site. The substitution showed that H9N2 AIVs had the potential affinity to bind to human-like receptor. The currently prevalent H9N2 AIVs in Shandong belonged to the lineage h9.4.2.5 which are different from the vaccine strain SS/94 clade h9.4.2.3. Therefore, the long-term surveillance of H9N2 AIVs is of significance to combat the possible H9N2 AIV outbreaks.

Evolutionary characterization of hemagglutinin gene of H9N2 influenza viruses isolated from Asia.

PubMed

Shahsavandi, Shahla; Salmanian, Ali-Hatef; Ghorashi, Seyed Ali; Masoudi, Shahin; Ebrahimi, Mohammad Majid

2012-08-01

The full length hemagglutinin (HA) genes of 287 H9N2 AI strains isolated from chickens in Asia during the period 1994-2009 were genetically analyzed. Phylogenetic analysis showed that G1-like viruses circulated in the Middle East and Indian sub-continent countries, whereas other sublineages existed in Far East countries. It also revealed G1-like viruses with an average 96.7% identity clustered into two subgroups largely based on their time of isolation. The Ka/Ks ratio was calculated 0.34 for subgroup 1 and 0.57 for subgroup 2 indicates purifying/stabilizing selection, but despite this there is evidence of localized positive selection when comparing the subgroups 1 and 2 protein sequences. Five sites in HA H9N2 viruses had a posterior probability >0.5 using the Bayesian method, indicating these sites were under positive selection. These sites were found to be associated with the globular head region of HA. To identify sites under positive selection; amino acid substitution classified depends on their radicalism and neutrality. The results indicate that, although most positions in HAs were under purifying selection and can be eliminated, a few positions located in the antigenic regions and receptor binding sites were subject to positive selection. Copyright © 2011 Elsevier Ltd. All rights reserved.

The Continuing Evolution of H5N1 and H9N2 Influenza Viruses in Bangladesh

PubMed Central

Marinova-Petkova, Atanaska; Shanmuganatham, Karthik; Feeroz, Mohammed M.; Jones-Engel, Lisa; Hassan, M. Kamrul; Akhtar, Sharmin; Turner, Jasmine; Walker, David; Seiler, Patrick; Franks, John; McKenzie, Pamela; Krauss, Scott; Webby, Richard J.; Webster, Robert G.

2017-01-01

Summary In 2011, avian influenza surveillance at the Bangladesh live bird markets (LBMs) showed complete replacement of the highly pathogenic avian influenza (HPAI) H5N1 virus of clade 2.2.2 (Qinghai-like H5N1 lineage) by the HPAI H5N1 clade 2.3.2.1. This clade, which continues to circulate in Bangladesh and neighboring countries, is an intra- and inter-clade reassortant; its HA, PB1, PA and NS genes come from subclade 2.3.2.1a; PB2 from subclade 2.3.2.1c; and NA, NP, and M from clade 2.3.4.2. The H9N2 influenza viruses co-circulating in the Bangladesh LBMs are also reassortants, possessing five genes (NS, M, NP, PA, and PB1) from a HPAI H7N3 virus previously isolated in Pakistan. Despite frequent co-infection of chickens and ducks, reassortment between these H5N1 and H9N2 viruses has been rare. However, all such reassortants detected in 2011 through 2013 have carried 7 genes from HPAI H5N1 clade 2.3.2.1a and the PB1 gene from the Bangladeshi H9N2 clade G1 Mideast, itself derived from HPAI H7N3 virus. Although, the live birds which we sampled in Bangladesh showed no clinical signs of morbidity, the emergence of this reassortant HPAI H5N1 lineage further complicates endemic circulation of H5N1 viruses in Bangladesh, posing a threat to both poultry and humans. PMID:27309046

Experimental Infection of Chickens with Intercontinental Reassortant H9N2 Influenza Viruses from Wild Birds.

PubMed

Lee, Dong-Hun; Kwon, Jung-Hoon; Park, Jae-Keun; Yuk, Seong-Su; Tseren-Ochir, Erdene-Ochir; Noh, Jin-Yong; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

2016-06-01

The H9N2 subtype of low pathogenic avian influenza (LPAI) virus is the most prevalent LPAI in domestic poultry. We previously reported the natural reassortant H9N2 viruses between North American and Eurasian lineages isolated from wild birds in Korea. These viruses were identified in China and Alaska, providing evidence of intercontinental dispersal. In this study, we evaluated the infectivity, transmissibility, and pathogenic potential of these H9N2 viruses and Eurasian H9N2 virus identified from wild birds using specific-pathogen-free chickens. Three-week-old chickens were infected intranasally. All of these reassortant H9N2 viruses could not be replicated and transmitted in chickens. On the other hand, three out of eight chickens inoculated with the Eurasian H9N2 virus shed detectable levels of virus and showed seroconversion but did not show contact transmission of the virus. Although all reassortant H9N2 viruses could not be replicated and transmitted in chickens, and although there are no reports on reassortant H9N2 virus infection in poultry farms until now, monitoring of reassortant H9N2 viruses should be continued to prepare for the advent and evolution of these viruses.

Avian influenza virus H9N2 infections in farmed minks.

PubMed

Zhang, Chuanmei; Xuan, Yang; Shan, Hu; Yang, Haiyan; Wang, Jianlin; Wang, Ke; Li, Guimei; Qiao, Jian

2015-11-02

The prevalence of avian H9N2 viruses throughout Asia, along with their demonstrated ability to infect mammals, puts them high on the list of influenza viruses with pandemic potential for humans. In this study, we investigated whether H9N2 viruses could infect farmed minks. First, we conducted a serological survey for avian influenza virus antibodies on a random sample of the field-trial population of farmed minks. Then we inoculated farmed minks with A/Chicken/Hebei/4/2008 H9N2 viruses and observed the potential pathogenicity of H9N2 virus and virus shedding in infected minks. H9 influenza antibodies could be detected in most farmed minks with a higher seropositivity, which indicated that farmed minks had the high prevalence of exposure to H9 viruses. After infection, the minks displayed the slight clinical signs including lethargy and initial weight loss. The infected lungs showed the mild diffuse pneumonia with thickened alveolar walls and inflammatory cellular infiltration. Influenza virus detection showed that viruses were detected in the allantoic fluids inoculated supernatant of lung tissues at 3 and 7 days post-infection (dpi), and found in the nasal swabs of H9N2-infected minks at 3-11 dpi, suggesting that H9N2 viruses replicated in the respiratory organ, were then shed outwards. HI antibody test showed that antibody levels began to rise at 7 dpi. Our data provided the serological and experimental evidences that strongly suggested farmed minks under the natural state were susceptible to H9N2 viral infection and might be the H9N2 virus carriers. It is imperative to strengthen the H9N2 viral monitoring in farmed minks and pay urgent attention to prevent and control new influenza viruses pandemic prevalence.

Convergent Evolution of Human-Isolated H7N9 Avian Influenza A Viruses.

PubMed

Xiang, Dan; Shen, Xuejuan; Pu, Zhiqing; Irwin, David M; Liao, Ming; Shen, Yongyi

2018-05-05

Avian influenza A virus H7N9 has caused 5 epidemic waves of human infections in China since 2013. Avian influenza A viruses may face strong selection to adapt to novel conditions when establishing themselves in humans. In this study, we sought to determine whether adaptive evolution had occurred in human-isolated H7N9 viruses. We evaluated all available genomes of H7N9 avian influenza A virus. Maximum likelihood trees were separately reconstructed for all 8 genes. Signals of positive selection and convergent evolution were then detected on branches that lead to changes in host tropism (from avian to human). We found that 3 genes had significant signals of positive selection (all of them P < .05). In addition, we detected 34 sites having significant signals for parallel evolution in 8 genes (all of them P < .05), including 7 well-known sites (Q591K, E627K, and D701N in PB2 gene; R156K, V202A, and L244Q in HA; and R289K in NA) that play roles in crossing species barriers for avian influenza A viruses. Our study suggests that, during infection in humans, H7N9 viruses have undergone adaptive evolution to adapt to their new host environment and that the sites where parallel evolution occurred might play roles in crossing species barriers and respond to the new selection pressures arising from their new host environments.

Infection and transmission of LPAIV H9N2 viruses in SPF chickens

USDA-ARS?s Scientific Manuscript database

Low pathogenic avian influenza viruses (LPAIV), subtype H9N2 are responsible for economic losses in the poultry industry worldwide. Using multiple strains of H9N2 LPAIV isolates from different years and countries, we inoculated 3-week old SPF laying hens intranasally to evaluate infectivity and tran...

Vaccination against H9N2 avian influenza virus reduces bronchus-associated lymphoid tissue formation in cynomolgus macaques after intranasal virus challenge infection.

PubMed

Nakayama, Misako; Ozaki, Hiroichi; Itoh, Yasushi; Soda, Kosuke; Ishigaki, Hirohito; Okamatsu, Masatoshi; Sakoda, Yoshihiro; Park, Chun-Ho; Tsuchiya, Hideaki; Kida, Hiroshi; Ogasawara, Kazumasa

2016-12-01

H9N2 avian influenza virus causes sporadic human infection. Since humans do not possess acquired immunity specific to this virus, we examined the pathogenicity of an H9N2 virus isolated from a human and then analyzed protective effects of a vaccine in cynomolgus macaques. After intranasal challenge with A/Hong Kong/1073/1999 (H9N2) (HK1073) isolated from a human patient, viruses were isolated from nasal and tracheal swabs in unvaccinated macaques with mild fever and body weight loss. A formalin-inactivated H9N2 whole particle vaccine derived from our virus library was subcutaneously inoculated to macaques. Vaccination induced viral antigen-specific IgG and neutralization activity in sera. After intranasal challenge with H9N2, the virus was detected only the day after inoculation in the vaccinated macaques. Without vaccination, many bronchus-associated lymphoid tissues (BALTs) were formed in the lungs after infection, whereas the numbers of BALTs were smaller and the cytokine responses were weaker in the vaccinated macaques than those in the unvaccinated macaques. These findings indicate that the H9N2 avian influenza virus HK1073 is pathogenic in primates but seems to cause milder symptoms than does H7N9 influenza virus as found in our previous studies and that a formalin-inactivated H9N2 whole particle vaccine induces protective immunity against H9N2 virus. © 2016 Japanese Society of Pathology and John Wiley & Sons Australia, Ltd.

Infectivity, transmission, and pathology of human-isolated H7N9 influenza virus in ferrets and pigs.

PubMed

Zhu, H; Wang, D; Kelvin, D J; Li, L; Zheng, Z; Yoon, S-W; Wong, S-S; Farooqui, A; Wang, J; Banner, D; Chen, R; Zheng, R; Zhou, J; Zhang, Y; Hong, W; Dong, W; Cai, Q; Roehrl, M H A; Huang, S S H; Kelvin, A A; Yao, T; Zhou, B; Chen, X; Leung, G M; Poon, L L M; Webster, R G; Webby, R J; Peiris, J S M; Guan, Y; Shu, Y

2013-07-12

The emergence of the H7N9 influenza virus in humans in Eastern China has raised concerns that a new influenza pandemic could occur. Here, we used a ferret model to evaluate the infectivity and transmissibility of A/Shanghai/2/2013 (SH2), a human H7N9 virus isolate. This virus replicated in the upper and lower respiratory tracts of the ferrets and was shed at high titers for 6 to 7 days, with ferrets showing relatively mild clinical signs. SH2 was efficiently transmitted between ferrets via direct contact, but less efficiently by airborne exposure. Pigs were productively infected by SH2 and shed virus for 6 days but were unable to transmit the virus to naïve pigs or ferrets. Under appropriate conditions, human-to-human transmission of the H7N9 virus may be possible.

Detection of avian H7N9 influenza A viruses at the Yangtze Delta Region of China during early H7N9 outbreaks

PubMed Central

Li, Yin; Huang, Xin-mei; Zhao, Dong-min; Liu, Yu-zhuo; He, Kong-wang; Liu, Yao-xing; Chen, Chang-hai; Long, Li-Ping; Xu, Yifei; Xie, Xing-xing; Han, Kai-kai; Liu, Xiao-yan; Yang, Jing; Zhang, You-Fa; Fan, Feng; Webby, Richard; Wan, Xiu-Feng

2016-01-01

SUMMARY Since the first H7N9 human case in Shanghai, February 19, 2013, the emerging avian-origin H7N9 influenza A virus has become an epizootic virus in China, posing a potential pandemic threat to public health. From April 2 to April 28, 2013, 422 oral-pharyngeal and cloacal swabs were collected from birds and environmental surfaces at five live poultry markets (LPMs) and 13 backyard poultry farms (BPFs) across three cities, Wuxi, Suzhou, and Nanjing, in the Yangtze Delta Region. A total of 22 isolates were recovered, and 6 were subtyped as H7N9, 9 as H9N2, 4 as H7N9/H9N2, and 3 un-subtyped influenza A viruses. Genomic sequences showed that the HA and NA genes of the H7N9 viruses were similar to those of the H7N9 human isolates as well as other avian origin H7N9 isolates in the region but the PB1, PA, NP, and MP genes of the sequenced viruses were, however, more diverse. Among the four H7N9/H9N2 mixed infections, three were from LPM whereas the other one from the ducks at one BPF, which were H7N9 negative in serological analyses. A survey of the bird trading records of the LPMs and BPFs indicates that trading was a likely route for virus transmission across these regions. Our results suggested that a better biosecurity and more effective vaccination should be implemented in backyard farms besides biosecurity management in LPMs. PMID:27309047

Detection of Avian H7N9 Influenza A Viruses in the Yangtze Delta Region of China During Early H7N9 Outbreaks.

PubMed

Li, Yin; Huang, Xin-Mei; Zhao, Dong-Min; Liu, Yu-Zhuo; He, Kong-Wang; Liu, Yao-Xing; Chen, Chang-Hai; Long, Li-Ping; Xu, Yifei; Xie, Xing-Xing; Han, Kai-Kai; Liu, Xiao-Yan; Yang, Jing; Zhang, You-Fa; Fan, Feng; Webby, Richard; Wan, Xiu-Feng

2016-05-01

Since the first H7N9 human case in Shanghai, February 19, 2013, the emerging avian-origin H7N9 influenza A virus has become an epizootic virus in China, posing a potential pandemic threat to public health. From April 2 to April 28, 2013, some 422 oral-pharyngeal and cloacal swabs were collected from birds and environmental surfaces at five live poultry markets (LPMs) and 13 backyard poultry farms (BPFs) across three cities, Wuxi, Suzhou, and Nanjing, in the Yangtze Delta region. In total 22 isolates were recovered, and six were subtyped as H7N9, nine as H9N2, four as H7N9/H9N2, and three unsubtyped influenza A viruses. Genomic sequences showed that the HA and NA genes of the H7N9 viruses were similar to those of the H7N9 human isolates, as well as other avian-origin H7N9 isolates in the region, but the PB1, PA, NP, and MP genes of the sequenced viruses were more diverse. Among the four H7N9/H9N2 mixed infections, three were from LPM, whereas the other one was from the ducks at one BPF, which were H7N9 negative in serologic analyses. A survey of the bird trading records of the LPMs and BPFs indicates that trading was a likely route for virus transmission across these regions. Our results suggested that better biosecurity and more effective vaccination should be implemented in backyard farms, in addition to biosecurity management in LPMs.

Live attenuated H5N1 vaccine with H9N2 internal genes protects chickens from infections by both Highly Pathogenic H5N1 and H9N2 Influenza Viruses

PubMed Central

Nang, Nguyen Tai; Song, Byung Min; Kang, Young Myong; Kim, Heui Man; Kim, Hyun Soo; Seo, Sang Heui

2012-01-01

Please cite this paper as: Nang et al. (2013) Live attenuated H5N1 vaccine with H9N2 internal genes protects chickens from infections by both Highly Pathogenic H5N1 and H9N2 Influenza Viruses. Influenza and Other Respiratory Viruses 7(2) 120–131. Background  The highly pathogenic H5N1 and H9N2 influenza viruses are endemic in many countries around the world and have caused considerable economic loss to the poultry industry. Objectives  We aimed to study whether a live attenuated H5N1 vaccine comprising internal genes from a cold‐adapted H9N2 influenza virus could protect chickens from infection by both H5N1 and H9N2 viruses. Methods  We developed a cold‐adapted H9N2 vaccine virus expressing hemagglutinin and neuraminidase derived from the highly pathogenic H5N1 influenza virus using reverse genetics. Results and Conclusions  Chickens immunized with the vaccine were protected from lethal infections with homologous and heterologous H5N1 or H9N2 influenza viruses. Specific antibody against H5N1 virus was detected up to 11 weeks after vaccination (the endpoint of this study). In vaccinated chickens, IgA and IgG antibody subtypes were induced in lung and intestinal tissue, and CD4+ and CD8+ T lymphocytes expressing interferon‐gamma were induced in the splenocytes. These data suggest that a live attenuated H5N1 vaccine with cold‐adapted H9N2 internal genes can protect chickens from infection with H5N1 and H9N2 influenza viruses by eliciting humoral and cellular immunity. PMID:22487301

Evolutionary trajectories and diagnostic challenges of potentially zoonotic avian influenza viruses H5N1 and H9N2 co-circulating in Egypt.

PubMed

Naguib, Mahmoud M; Arafa, Abdel-Satar A; El-Kady, Magdy F; Selim, Abdullah A; Gunalan, Vithiagaran; Maurer-Stroh, Sebastian; Goller, Katja V; Hassan, Mohamed K; Beer, Martin; Abdelwhab, E M; Harder, Timm C

2015-08-01

In Egypt, since 2006, descendants of the highly pathogenic avian influenza virus (HP AIV) H5N1 of clade 2.2 continue to cause sharp losses in poultry production and seriously threaten public health. Potentially zoonotic H9N2 viruses established an endemic status in poultry in Egypt as well and co-circulate with HP AIV H5N1 rising concerns of reassortments between H9N2 and H5N1 viruses along with an increase of mixed infections of poultry. Nucleotide sequences of whole genomes of 15 different isolates (H5N1: 7; H9N2: 8), and of the hemagglutinin (HA) and neuraminidase (NA) encoding segments of nine further clinical samples (H5N1: 2; H9N2: 7) from 2013 and 2014 were generated and analysed. The HA of H5N1 viruses clustered with clade 2.2.1 while the H9 HA formed three distinguishable subgroups within cluster B viruses. BEAST analysis revealed that H9N2 viruses are likely present in Egypt since 2009. Several previously undescribed substituting mutations putatively associated with host tropism and virulence modulation were detected in different proteins of the analysed H9N2 and H5N1 viruses. Reassortment between HP AIV H5N1 and H9N2 is anticipated in Egypt, and timely detection of such events is of public health concern. As a rapid tool for detection of such reassortants discriminative SYBR-Green reverse transcription real-time PCR assays (SG-RT-qPCR), targeting the internal genes of the Egyptian H5N1 and H9N2 viruses were developed for the rapid screening of viral RNAs from both virus isolates and clinical samples. However, in accordance to Sanger sequencing, no reassortants were found by SG-RT-qPCR. Nevertheless, the complex epidemiology of avian influenza in poultry in Egypt will require sustained close observation. Further development and continuing adaptation of rapid and cost-effective screening assays such as the SG-RT-qPCR protocol developed here are at the basis of efforts for improvement the currently critical situation. Copyright © 2015 Elsevier B.V. All

Evolution of the H9N2 influenza genotype that facilitated the genesis of the novel H7N9 virus.

PubMed

Pu, Juan; Wang, Shuoguo; Yin, Yanbo; Zhang, Guozhong; Carter, Robert A; Wang, Jinliang; Xu, Guanlong; Sun, Honglei; Wang, Min; Wen, Chu; Wei, Yandi; Wang, Dongdong; Zhu, Baoli; Lemmon, Gordon; Jiao, Yuannian; Duan, Susu; Wang, Qian; Du, Qian; Sun, Meng; Bao, Jinnan; Sun, Yipeng; Zhao, Jixun; Zhang, Hui; Wu, Gang; Liu, Jinhua; Webster, Robert G

2015-01-13

The emergence of human infection with a novel H7N9 influenza virus in China raises a pandemic concern. Chicken H9N2 viruses provided all six of the novel reassortant's internal genes. However, it is not fully understood how the prevalence and evolution of these H9N2 chicken viruses facilitated the genesis of the novel H7N9 viruses. Here we show that over more than 10 y of cocirculation of multiple H9N2 genotypes, a genotype (G57) emerged that had changed antigenicity and improved adaptability in chickens. It became predominant in vaccinated farm chickens in China, caused widespread outbreaks in 2010-2013 before the H7N9 viruses emerged in humans, and finally provided all of their internal genes to the novel H7N9 viruses. The prevalence and variation of H9N2 influenza virus in farmed poultry could provide an important early warning of the emergence of novel reassortants with pandemic potential.

Characterization of an H9N2 avian influenza virus from a Fringilla montifringilla brambling in northern China.

PubMed

Yuan, Jing; Xu, Lili; Bao, Linlin; Yao, Yanfeng; Deng, Wei; Li, Fengdi; Lv, Qi; Gu, Songzhi; Wei, Qiang; Qin, Chuan

2015-02-01

Avian H9N2 influenza viruses circulating in domestic poultry populations are occasionally transmitted to humans. We report the genomic characterization of an H9N2 avian influenza virus (A/Brambling/Beijing/16/2012) first isolated from a healthy Fringilla montifringilla brambling in northern China in 2012. Phylogenetic analyses revealed that this H9N2 virus belongs to the BJ/94-like sublineage. This virus had a low pathogenicity for chickens and was able to replicate at a low level in mouse lung tissue. Transmission studies in ferrets showed that this H9N2 strain shed high levels of the virus in nasal and throat swabs. In vitro receptor binding assays, the virus bound only to α-2,6 linkage receptors and not to the avian-type α-2,3 linkage receptors, suggesting that H9N2 influenza viruses present potential public health risks. Therefore, attention should be paid to H9N2 influenza viruses and the close surveillance of H9N2 viruses in poultry. Copyright © 2014 Elsevier Inc. All rights reserved.

A Novel Activation Mechanism of Avian Influenza Virus H9N2 by Furin

PubMed Central

Tse, Longping V.; Hamilton, Alice M.; Friling, Tamar

2014-01-01

Avian influenza virus H9N2 is prevalent in waterfowl and has become endemic in poultry in Asia and the Middle East. H9N2 influenza viruses have served as a reservoir of internal genes for other avian influenza viruses that infect humans, and several cases of human infection by H9N2 influenza viruses have indicated its pandemic potential. Fortunately, an extensive surveillance program enables close monitoring of H9N2 influenza viruses worldwide and has generated a large repository of virus sequences and phylogenetic information. Despite the large quantity of sequences in different databases, very little is known about specific virus isolates and their pathogenesis. Here, we characterize a low-pathogenicity avian influenza virus, A/chicken/Israel/810/2001 (H9N2) (Israel810), which is representative of influenza virus strains that have caused severe morbidity and mortality in poultry farms. We show that under certain circumstances the Israel810 hemagglutinin (HA) can be activated by furin, a hallmark of highly pathogenic avian influenza virus. We demonstrate that Israel810 HA can be cleaved in cells with high levels of furin expression and that a mutation that eliminates a glycosylation site in HA1 allows the Israel810 HA to gain universal cleavage in cell culture. Pseudoparticles generated from Israel810 HA, or the glycosylation mutant, transduce cells efficiently. In contrast, introduction of a polybasic cleavage site into Israel810 HA leads to pseudoviruses that are compromised for transduction. Our data indicate a mechanism for an H9N2 evolutionary pathway that may allow it to gain virulence in a distinct manner from H5 and H7 influenza viruses. PMID:24257604

Genetics, Receptor Binding Property, and Transmissibility in Mammals of Naturally Isolated H9N2 Avian Influenza Viruses

PubMed Central

Deng, Guohua; Zhang, Qianyi; Wang, Jinliang; He, Xijun; Wang, Kaicheng; Chen, Jiming; Li, Yuanyuan; Fan, Jun; Kong, Huiui; Gu, Chunyang; Guan, Yuantao; Suzuki, Yasuo; Kawaoka, Yoshihiro; Liu, Liling; Jiang, Yongping; Tian, Guobin; Li, Yanbing; Bu, Zhigao; Chen, Hualan

2014-01-01

H9N2 subtype influenza viruses have been detected in different species of wild birds and domestic poultry in many countries for several decades. Because these viruses are of low pathogenicity in poultry, their eradication is not a priority for animal disease control in many countries, which has allowed them to continue to evolve and spread. Here, we characterized the genetic variation, receptor-binding specificity, replication capability, and transmission in mammals of a series of H9N2 influenza viruses that were detected in live poultry markets in southern China between 2009 and 2013. Thirty-five viruses represented 17 genotypes on the basis of genomic diversity, and one specific “internal-gene-combination” predominated among the H9N2 viruses. This gene combination was also present in the H7N9 and H10N8 viruses that have infected humans in China. All of the 35 viruses preferentially bound to the human-like receptor, although two also retained the ability to bind to the avian-like receptor. Six of nine viruses tested were transmissible in ferrets by respiratory droplet; two were highly transmissible. Some H9N2 viruses readily acquired the 627K or 701N mutation in their PB2 gene upon infection of ferrets, further enhancing their virulence and transmission in mammals. Our study indicates that the widespread dissemination of H9N2 viruses poses a threat to human health not only because of the potential of these viruses to cause an influenza pandemic, but also because they can function as “vehicles” to deliver different subtypes of influenza viruses from avian species to humans. PMID:25411973

Phylogenetic Diversity and Genotypical Complexity of H9N2 Influenza A Viruses Revealed by Genomic Sequence Analysis

PubMed Central

Dong, Guoying; Luo, Jing; Zhang, Hong; Wang, Chengmin; Duan, Mingxing; Deliberto, Thomas Jude; Nolte, Dale Louis; Ji, Guangju; He, Hongxuan

2011-01-01

H9N2 influenza A viruses have become established worldwide in terrestrial poultry and wild birds, and are occasionally transmitted to mammals including humans and pigs. To comprehensively elucidate the genetic and evolutionary characteristics of H9N2 influenza viruses, we performed a large-scale sequence analysis of 571 viral genomes from the NCBI Influenza Virus Resource Database, representing the spectrum of H9N2 influenza viruses isolated from 1966 to 2009. Our study provides a panoramic framework for better understanding the genesis and evolution of H9N2 influenza viruses, and for describing the history of H9N2 viruses circulating in diverse hosts. Panorama phylogenetic analysis of the eight viral gene segments revealed the complexity and diversity of H9N2 influenza viruses. The 571 H9N2 viral genomes were classified into 74 separate lineages, which had marked host and geographical differences in phylogeny. Panorama genotypical analysis also revealed that H9N2 viruses include at least 98 genotypes, which were further divided according to their HA lineages into seven series (A–G). Phylogenetic analysis of the internal genes showed that H9N2 viruses are closely related to H3, H4, H5, H7, H10, and H14 subtype influenza viruses. Our results indicate that H9N2 viruses have undergone extensive reassortments to generate multiple reassortants and genotypes, suggesting that the continued circulation of multiple genotypical H9N2 viruses throughout the world in diverse hosts has the potential to cause future influenza outbreaks in poultry and epidemics in humans. We propose a nomenclature system for identifying and unifying all lineages and genotypes of H9N2 influenza viruses in order to facilitate international communication on the evolution, ecology and epidemiology of H9N2 influenza viruses. PMID:21386964

Evolution of the H9N2 influenza genotype that facilitated the genesis of the novel H7N9 virus

PubMed Central

Pu, Juan; Wang, Shuoguo; Yin, Yanbo; Zhang, Guozhong; Carter, Robert A.; Wang, Jinliang; Xu, Guanlong; Sun, Honglei; Wang, Min; Wen, Chu; Wei, Yandi; Wang, Dongdong; Zhu, Baoli; Lemmon, Gordon; Jiao, Yuannian; Duan, Susu; Wang, Qian; Du, Qian; Sun, Meng; Bao, Jinnan; Sun, Yipeng; Zhao, Jixun; Zhang, Hui; Wu, Gang; Liu, Jinhua; Webster, Robert G.

2015-01-01

The emergence of human infection with a novel H7N9 influenza virus in China raises a pandemic concern. Chicken H9N2 viruses provided all six of the novel reassortant’s internal genes. However, it is not fully understood how the prevalence and evolution of these H9N2 chicken viruses facilitated the genesis of the novel H7N9 viruses. Here we show that over more than 10 y of cocirculation of multiple H9N2 genotypes, a genotype (G57) emerged that had changed antigenicity and improved adaptability in chickens. It became predominant in vaccinated farm chickens in China, caused widespread outbreaks in 2010–2013 before the H7N9 viruses emerged in humans, and finally provided all of their internal genes to the novel H7N9 viruses. The prevalence and variation of H9N2 influenza virus in farmed poultry could provide an important early warning of the emergence of novel reassortants with pandemic potential. PMID:25548189

Pathogenicity and Transmission in Pigs of the Novel A(H3N2)v Influenza Virus Isolated from Humans and Characterization of Swine H3N2 Viruses Isolated in 2010-2011

PubMed Central

Kitikoon, Pravina; Gauger, Phillip C.; Schlink, Sarah N.; Bayles, Darrell O.; Gramer, Marie R.; Darnell, Daniel; Webby, Richard J.; Lager, Kelly M.; Swenson, Sabrina L.; Klimov, Alexander

2012-01-01

Swine influenza virus (SIV) H3N2 with triple reassorted internal genes (TRIG) has been enzootic in Unites States since 1998. Transmission of the 2009 pandemic H1N1 (pH1N1) virus to pigs in the United States was followed by reassortment with endemic SIV, resulting in reassorted viruses that include novel H3N2 genotypes (rH3N2p). Between July and December 2011, 12 cases of human infections with swine-lineage H3N2 viruses containing the pandemic matrix (pM) gene [A(H3N2)v] were detected. Whole-genome analysis of H3N2 viruses isolated from pigs from 2009 to 2011 sequenced in this study and other available H3N2 sequences showed six different rH3N2p genotypes present in the U.S. swine population since 2009. The presence of the pM gene was a common feature among all rH3N2p genotypes, but no specific genotype appeared to predominate in the swine population. We compared the pathogenic, transmission, genetic, and antigenic properties of a human A(H3N2)v isolate and two swine H3N2 isolates, H3N2-TRIG and rH3N2p. Our in vivo study detected no increased virulence in A(H3N2)v or rH3N2p viruses compared to endemic H3N2-TRIG virus. Antibodies to cluster IV H3N2-TRIG and rH3N2p viruses had reduced cross-reactivity to A(H3N2)v compared to other cluster IV H3N2-TRIG and rH3N2p viruses. Genetic analysis of the hemagglutinin gene indicated that although rH3N2p and A(H3N2)v are related to cluster IV of H3N2-TRIG, some recent rH3N2p isolates appeared to be forming a separate cluster along with the human isolates of A(H3N2)v. Continued monitoring of these H3N2 viruses is necessary to evaluate the evolution and potential loss of population immunity in swine and humans. PMID:22491461

Pathogenicity and transmission in pigs of the novel A(H3N2)v influenza virus isolated from humans and characterization of swine H3N2 viruses isolated in 2010-2011.

PubMed

Kitikoon, Pravina; Vincent, Amy L; Gauger, Phillip C; Schlink, Sarah N; Bayles, Darrell O; Gramer, Marie R; Darnell, Daniel; Webby, Richard J; Lager, Kelly M; Swenson, Sabrina L; Klimov, Alexander

2012-06-01

Swine influenza virus (SIV) H3N2 with triple reassorted internal genes (TRIG) has been enzootic in Unites States since 1998. Transmission of the 2009 pandemic H1N1 (pH1N1) virus to pigs in the United States was followed by reassortment with endemic SIV, resulting in reassorted viruses that include novel H3N2 genotypes (rH3N2p). Between July and December 2011, 12 cases of human infections with swine-lineage H3N2 viruses containing the pandemic matrix (pM) gene [A(H3N2)v] were detected. Whole-genome analysis of H3N2 viruses isolated from pigs from 2009 to 2011 sequenced in this study and other available H3N2 sequences showed six different rH3N2p genotypes present in the U.S. swine population since 2009. The presence of the pM gene was a common feature among all rH3N2p genotypes, but no specific genotype appeared to predominate in the swine population. We compared the pathogenic, transmission, genetic, and antigenic properties of a human A(H3N2)v isolate and two swine H3N2 isolates, H3N2-TRIG and rH3N2p. Our in vivo study detected no increased virulence in A(H3N2)v or rH3N2p viruses compared to endemic H3N2-TRIG virus. Antibodies to cluster IV H3N2-TRIG and rH3N2p viruses had reduced cross-reactivity to A(H3N2)v compared to other cluster IV H3N2-TRIG and rH3N2p viruses. Genetic analysis of the hemagglutinin gene indicated that although rH3N2p and A(H3N2)v are related to cluster IV of H3N2-TRIG, some recent rH3N2p isolates appeared to be forming a separate cluster along with the human isolates of A(H3N2)v. Continued monitoring of these H3N2 viruses is necessary to evaluate the evolution and potential loss of population immunity in swine and humans.

Transmissibility of novel H7N9 and H9N2 avian influenza viruses between chickens and ferrets.

PubMed

Ku, Keun Bon; Park, Eun Hye; Yum, Jung; Kim, Heui Man; Kang, Young Myong; Kim, Jeong Cheol; Kim, Ji An; Kim, Hyun Soo; Seo, Sang Heui

2014-02-01

Previous studies have shown that the H7N9 avian influenza virus cannot be transmitted efficiently between ferrets via respiratory droplets. Here, we studied the infectivity of the H7N9 avian influenza virus in chickens and its transmissibility from infected to naïve chickens and ferrets. The H7N9 virus (A/Anhui/1/2013) replicated poorly in chickens and could not be transmitted efficiently from infected chickens to naïve chickens and ferrets. H7N9 virus was shed from chicken tracheae for only 2 days after infection and from chicken cloacae for only 1 day after infection, while the H9N2 avian influenza virus, which is endemic in chickens in many Asian countries, was shed from tracheae and cloacae for 8 days after infection. Taken together, our results suggest that chickens may be a poor agent of transmission for the H7N9 virus to other chickens and to mammals, including humans. Copyright © 2014 Elsevier Inc. All rights reserved.

Beagle dogs have low susceptibility to BJ94-like H9N2 avian influenza virus.

PubMed

Zhou, Pei; Wang, Lifang; Huang, San; Fu, Cheng; He, Huamei; Hong, Malin; Su, Shuo; Li, Shoujun

2015-04-01

In China, dogs are considered significant intermediate hosts of influenza viruses and have been reported to be infected with H9N2; additionally, a reassortant H9N2 virus has been isolated in dogs. Currently, there are three different lineages of H9N2, including BJ94-like, G1-like, and Y439-like lineages; BJ94-like H9N2 has been circulating in various types of poultry in southern China. Additionally, a number of studies have reported that H9N2 evolves rapidly and is frequently reassorted with H5N1, H7N9, or H10N8 to generate novel reassortants, which is significant for poultry and humans. In this study, two groups of beagles were inoculated either intranasally or intratracheally with the BJ94-like H9N2 virus. However, only four of the seven beagles in the intranasal group and five of the seven beagles in the intratracheal group displayed a mild fever; similarly, only two of the five beagles in the intranasal group and three of the five beagles in the intratracheal group underwent seroconversion. However, no viruses were detected from nasal swabs or rectal swabs or in the lungs of any of the inoculated beagles. Our results demonstrated that beagles have low susceptibility to the BJ94-like H9N2 avian influenza virus, which is the main virus circulating in southern China, indicating that the BJ94-like H9N2 virus does not currently threaten the health of dogs. Copyright © 2015 Elsevier B.V. All rights reserved.

Generation of a reassortant avian influenza virus H5N2 vaccine strain capable of protecting chickens against infection with Egyptian H5N1 and H9N2 viruses.

PubMed

Kandeil, Ahmed; Moatasim, Yassmin; Gomaa, Mokhtar R; Shehata, Mahmoud M; El-Shesheny, Rabeh; Barakat, Ahmed; Webby, Richard J; Ali, Mohamed A; Kayali, Ghazi

2016-01-04

Avian influenza H5N1 viruses have been enzootic in Egyptian poultry since 2006. Avian influenza H9N2 viruses which have been circulating in Egyptian poultry since 2011 showed high replication rates in embryonated chicken eggs and mammalian cells. To investigate which gene segment was responsible for increasing replication, we constructed reassortant influenza viruses using the low pathogenic H1N1 PR8 virus as backbone and included individual genes from A/chicken/Egypt/S4456B/2011(H9N2) virus. Then, we invested this finding to improve a PR8-derived H5N1 influenza vaccine strain by incorporation of the NA segment of H9N2 virus instead of the NA of H5N1. The growth properties of this virus and several other forms of reassortant H5 viruses were compared. Finally, we tested the efficacy of this reassortant vaccine strain in chickens. We observed an increase in replication for a reassortant virus expressing the neuraminidase gene (N2) of H9N2 virus relative to that of either parental viruses or reassortant PR8 viruses expressing other genes. Then, we generated an H5N2 vaccine strain based on the H5 from an Egyptian H5N1 virus and the N2 from an Egyptian H9N2 virus on a PR8 backbone. This strain had better replication rates than an H5N2 reassortant strain on an H9N2 backbone and an H5N1 reassortant on a PR8 backbone. This virus was then used to develop a killed, oil-emulsion vaccine and tested for efficacy against H5N1 and H9N2 viruses in chickens. Results showed that this vaccine was immunogenic and reduced mortality and shedding. Our findings suggest that an inactivated PR8-derived H5N2 influenza vaccine is efficacious in poultry against H5N1 and H9N2 viruses and the vaccine seed replicates at a high rate thus improving vaccine production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prevailing PA Mutation K356R in Avian Influenza H9N2 Virus Increases Mammalian Replication and Pathogenicity.

PubMed

Xu, Guanlong; Zhang, Xuxiao; Gao, Weihua; Wang, Chenxi; Wang, Jinliang; Sun, Honglei; Sun, Yipeng; Guo, Lu; Zhang, Rui; Chang, Kin-Chow; Liu, Jinhua; Pu, Juan

2016-09-15

Adaptation of the viral polymerase complex comprising PB1, PB2, and PA is necessary for efficient influenza A virus replication in new host species. We found that PA mutation K356R (PA-K356R) has become predominant since 2014 in avian H9N2 viruses in China as with seasonal human H1N1 viruses. The same mutation is also found in most human isolates of emergent avian H7N9 and H10N8 viruses whose six internal gene segments are derived from the H9N2 virus. We further demonstrated the mammalian adaptive functionality of the PA-K356R mutation. Avian H9N2 virus with the PA-K356R mutation in human A549 cells showed increased nuclear accumulation of PA and increased viral polymerase activity that resulted in elevated levels of viral transcription and virus output. The same mutant virus in mice also enhanced virus replication and caused lethal infection. In addition, combined mutation of PA-K356R and PB2-E627K, a well-known mammalian adaptive marker, in the H9N2 virus showed further cooperative increases in virus production and severity of infection in vitro and in vivo In summary, PA-K356R behaves as a novel mammalian tropism mutation, which, along with other mutations such as PB2-E627K, might render avian H9N2 viruses adapted for human infection. Mutations of the polymerase complex (PB1, PB2, and PA) of influenza A virus are necessary for viral adaptation to new hosts. This study reports a novel and predominant mammalian adaptive mutation, PA-K356R, in avian H9N2 viruses and human isolates of emergent H7N9 and H10N8 viruses. We found that PA-356R in H9N2 viruses causes significant increases in virus replication and severity of infection in human cells and mice and that PA-K356R cooperates with the PB2-E627K mutation, a well-characterized human adaptive marker, to exacerbate mammalian infection in vitro and in vivo Therefore, the PA-K356R mutation is a significant adaptation in H9N2 viruses and related H7N9 and H10N8 reassortants toward human infectivity. Copyright © 2016

Prevailing PA Mutation K356R in Avian Influenza H9N2 Virus Increases Mammalian Replication and Pathogenicity

PubMed Central

Xu, Guanlong; Zhang, Xuxiao; Gao, Weihua; Wang, Chenxi; Wang, Jinliang; Sun, Honglei; Sun, Yipeng; Guo, Lu; Zhang, Rui; Chang, Kin-Chow; Liu, Jinhua

2016-01-01

ABSTRACT Adaptation of the viral polymerase complex comprising PB1, PB2, and PA is necessary for efficient influenza A virus replication in new host species. We found that PA mutation K356R (PA-K356R) has become predominant since 2014 in avian H9N2 viruses in China as with seasonal human H1N1 viruses. The same mutation is also found in most human isolates of emergent avian H7N9 and H10N8 viruses whose six internal gene segments are derived from the H9N2 virus. We further demonstrated the mammalian adaptive functionality of the PA-K356R mutation. Avian H9N2 virus with the PA-K356R mutation in human A549 cells showed increased nuclear accumulation of PA and increased viral polymerase activity that resulted in elevated levels of viral transcription and virus output. The same mutant virus in mice also enhanced virus replication and caused lethal infection. In addition, combined mutation of PA-K356R and PB2-E627K, a well-known mammalian adaptive marker, in the H9N2 virus showed further cooperative increases in virus production and severity of infection in vitro and in vivo. In summary, PA-K356R behaves as a novel mammalian tropism mutation, which, along with other mutations such as PB2-E627K, might render avian H9N2 viruses adapted for human infection. IMPORTANCE Mutations of the polymerase complex (PB1, PB2, and PA) of influenza A virus are necessary for viral adaptation to new hosts. This study reports a novel and predominant mammalian adaptive mutation, PA-K356R, in avian H9N2 viruses and human isolates of emergent H7N9 and H10N8 viruses. We found that PA-356R in H9N2 viruses causes significant increases in virus replication and severity of infection in human cells and mice and that PA-K356R cooperates with the PB2-E627K mutation, a well-characterized human adaptive marker, to exacerbate mammalian infection in vitro and in vivo. Therefore, the PA-K356R mutation is a significant adaptation in H9N2 viruses and related H7N9 and H10N8 reassortants toward human

Avian influenza H9N2 virus isolated from air samples in LPMs in Jiangxi, China.

PubMed

Zeng, Xiaoxu; Liu, Mingbin; Zhang, Heng; Wu, Jingwen; Zhao, Xiang; Chen, Wenbing; Yang, Lei; He, Fenglan; Fan, Guoyin; Wang, Dayan; Chen, Haiying; Shu, Yuelong

2017-07-24

Recently, avian influenza virus has caused repeated worldwide outbreaks in humans. Live Poultry Markets (LPMs) play an important role in the circulation and reassortment of novel Avian Influenza Virus (AIVs). Aerosol transmission is one of the most important pathways for influenza virus to spread among poultry, from poultry to mammals, and among mammals. In this study, air samples were collected from LPMs in Nanchang city between April 2014 and March 2015 to investigate possible aerosol transmission of AIVs. Air samples were detected for Flu A by Real-Time Reverse Transcription-Polymerase Chain Reaction (RRT-PCR). If samples were positive for Flu A, they were inoculated into 9- to 10-day-old specific-pathogen-free embryonated eggs. If the result was positive, the whole genome of the virus was sequenced by MiSeq. Phylogenetic trees of all 8 segments were constructed using MEGA 6.05 software. To investigate the possible aerosol transmission of AIVs, 807 air samples were collected from LPMs in Nanchang city between April 2014 and March 2015. Based on RRT-PCR results, 275 samples (34.1%) were Flu A positive, and one virus was successfully isolated with embryonated eggs. The virus shared high nucleotide homology with H9N2 AIVs from South China. Our study provides further evidence that the air in LPMs can be contaminated by influenza viruses and their nucleic acids, and this should be considered when choosing and evaluating disinfection strategies in LPMs, such as regular air disinfection. Aerosolized viruses such as the H9N2 virus detected in this study can increase the risk of human infection when people are exposed in LPMs.

Phylogenetic analysis of H9N2 avian influenza viruses in Afghanistan (2016-2017).

PubMed

Hosseini, Hossein; Ghalyanchilangeroudi, Arash; Fallah Mehrabadi, Mohammad Hossein; Sediqian, Mohammad Saeed; Shayeganmehr, Arzhang; Ghafouri, Seyed Ali; Maghsoudloo, Hossein; Abdollahi, Hamed; Farahani, Reza Kh

2017-10-01

Avian influenza A virus (AIV) subtype H9N2 is the most prevalent subtype found in terrestrial poultry throughout Eurasia and has been isolated from poultry outbreaks worldwide. Tracheal tissue specimens from 100 commercial broiler flocks in Afghanistan were collected between 2016 and 2017. After real-time RT-PCR, AI-positive samples were further characterized. A part of the HA gene was amplified using RT-PCR and sequenced. The results of real-time RT-PCR showed that 40 percent of the flocks were AI positive. Phylogenetic studies showed that these H9N2 AIVs grouped within the Eurasian-lineage G1 AIVs and had a correlation with H9N2 AIV circulating in the poultry population of the neighboring countries over the past decade. Analysis of the amino acid sequence of HA revealed that the detected H9N2 viruses possessed molecular profiles suggestive of low pathogenicity and specificity for the avian-like SAα2,3 receptor, demonstrating their specificity for and adaptation to domestic poultry. The results of the current study provide great insights into H9N2 viruses circulating in Afghanistan's poultry industry and demonstrate the necessity of planning an applied policy aimed at controlling and managing H9N2 infection in Afghan poultry.

Characterization of Avian H9N2 Influenza Viruses from United Arab Emirates 2000 to 2003

PubMed Central

Aamir, U. B.; Wernery, Ulrich; Ilyushina, N.; Webster, R. G.

2009-01-01

Our aim was to establish the phylogenetic relation of H9N2 avian viruses in the Middle East to other Asian H9N2 lineages by characterization of 7 viruses isolated from United Arab Emirates (2000-2003). All these viruses had an additional basic amino acid at the hemagglutinin-connecting peptide; 6 contained a mutation associated with increased affinity toward human-like sialic acid substrates. The viruses' surface glycoproteins and most internal genes were >90% similar to those of A/Quail/Hong Kong/G1/97 (H9N2) lineage. The hemadsorbing site of neuraminidase had up to 4 amino acid substitutions, as do human pandemic viruses. M2 sequence analysis revealed amino acid changes at 2 positions, with increasing resistance to amantadine in cell culture. They replicated efficiently in inoculated chickens and were successfully transmitted to contacts. They continue to maintain H5N1-like genes and may augment the spread of H5N1 viruses through regional co-circulation and inapparent infection. These viruses may present as potential pandemic candidates themselves. PMID:17157891

Characterization of Low Pathogenic Avian Influenza Virus Subtype H9N2 Isolated from Free-Living Mynah Birds (Acridotheres tristis) in the Sultanate of Oman.

PubMed

Body, Mohammad H; Alrarawahi, Abdulmajeed H; Alhubsy, Saif S; Saravanan, Nirmala; Rajmony, Sunil; Mansoor, Muhammad Khalid

2015-06-01

A low pathogenic avian influenza virus was identified from free-living birds (mynah, Acridotheres tristis) of the starling family. Virus was isolated by inoculation of homogenized suspension from lung, tracheal, spleen, and cloacal swabs into the allantoic cavity of embryonated chicken eggs. Subtype of the isolate was characterized as H9N2 by hemagglutination inhibition test using monospecific chicken antisera to a wide range of influenza reference strain. Pathogenicity of the isolate was determined by intravenous pathogenicity index. The virus was reisolated from experimentally infected chicken. Additionally, the isolate was subjected to reverse transcriptase PCR using partial hemagglutinin (HA) gene-specific primers and yielded an amplicon of 487 bp. HA gene sequence analysis revealed 99% sequence homology among mynah and chicken isolates from Oman. On phylogenetic analysis, isolates from mynah (A/mynnah/Oman/AIVS6/2005) and chicken (A/chicken/Oman/AIVS3/2006; A/chicken/Oman/AIVS7/2006) clustered together tightly, indicating these free-flying birds may be a source of introduction of H9N2 subtype in poultry bird in Oman. Moreover, the HA gene of H9N2 isolates from Oman resembled those of viruses of the G1-like lineage and were very similar to those from United Arab Emirates.

The Continuing Evolution of H5N1 and H9N2 Influenza Viruses in Bangladesh Between 2013 and 2014.

PubMed

Marinova-Petkova, Atanaska; Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Hasan, M Kamrul; Akhtar, Sharmin; Turner, Jasmine; Walker, David; Seiler, Patrick; Franks, John; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2016-05-01

In 2011, avian influenza surveillance at the Bangladesh live bird markets (LBMs) showed complete replacement of the highly pathogenic avian influenza (HPAI) H5N1 virus of clade 2.2.2 (Qinghai-like H5N1 lineage) by the HPAI H5N1 clade 2.3.2.1. This clade, which continues to circulate in Bangladesh and neighboring countries, is an intra-and interclade reassortant; its HA, polymerase basic 1 (PB1), polymerase (PA), and nonstructural (NS) genes come from subclade 2.3.2.1a; the polymerase basic 2 (PB2) comes from subclade 2.3.2.1c; and the NA, nucleocapsid protein (NP), and matrix (M) gene from clade 2.3.4.2. The H9N2 influenza viruses cocirculating in the Bangladesh LBMs are also reassortants, possessing five genes (NS, M, NP, PA, and PB1) from an HPAI H7N3 virus previously isolated in Pakistan. Despite frequent coinfection of chickens and ducks, reassortment between these H5N1 and H9N2 viruses has been rare. However, all such reassortants detected in 2011 through 2013 have carried seven genes from the local HPAI H5N1 lineage and the PB1 gene from the Bangladeshi H9N2 clade G1 Mideast, itself derived from HPAI H7N3 virus. Although the live birds we sampled in Bangladesh showed no clinical signs of morbidity, the emergence of this reassortant HPAI H5N1 lineage further complicates endemic circulation of H5N1 viruses in Bangladesh, posing a threat to both poultry and humans.

Imported Parakeets Harbor H9N2 Influenza A Viruses That Are Genetically Closely Related to Those Transmitted to Humans in Hong Kong

PubMed Central

Mase, Masaji; Imada, Tadao; Sanada, Yasuyuki; Etoh, Mariko; Sanada, Naoko; Tsukamoto, Kenji; Kawaoka, Yoshihiro; Yamaguchi, Shigeo

2001-01-01

In 1997 and 1998, H9N2 influenza A viruses were isolated from the respiratory organs of Indian ring-necked parakeets (Psittacula Krameri manillensis) that had been imported from Pakistan to Japan. The two isolates were closely related to each other (>99% as determined by nucleotide analysis of eight RNA segments), indicating that H9N2 viruses of the same lineage were maintained in these birds for at least 1 year. The hemagglutinins and neuraminidases of both isolates showed >97% nucleotide identity with those of H9N2 viruses isolated from humans in Hong Kong in 1999, while the six genes encoding internal proteins were >99% identical to the corresponding genes of H5N1 viruses recovered during the 1997 outbreak in Hong Kong. These results suggest that the H9N2 parakeet viruses originating in Pakistan share an immediate ancestor with the H9N2 human viruses. Thus, influenza A viruses with the potential to be transmitted directly to humans may be circulating in captive birds worldwide. PMID:11238878

Imported parakeets harbor H9N2 influenza A viruses that are genetically closely related to those transmitted to humans in Hong Kong.

PubMed

Mase, M; Imada, T; Sanada, Y; Etoh, M; Sanada, N; Tsukamoto, K; Kawaoka, Y; Yamaguchi, S

2001-04-01

In 1997 and 1998, H9N2 influenza A viruses were isolated from the respiratory organs of Indian ring-necked parakeets (Psittacula Krameri manillensis) that had been imported from Pakistan to Japan. The two isolates were closely related to each other (>99% as determined by nucleotide analysis of eight RNA segments), indicating that H9N2 viruses of the same lineage were maintained in these birds for at least 1 year. The hemagglutinins and neuraminidases of both isolates showed >97% nucleotide identity with those of H9N2 viruses isolated from humans in Hong Kong in 1999, while the six genes encoding internal proteins were >99% identical to the corresponding genes of H5N1 viruses recovered during the 1997 outbreak in Hong Kong. These results suggest that the H9N2 parakeet viruses originating in Pakistan share an immediate ancestor with the H9N2 human viruses. Thus, influenza A viruses with the potential to be transmitted directly to humans may be circulating in captive birds worldwide.

H7N9 influenza A virus in turkeys in Minnesota

USGS Publications Warehouse

Lebarbenchon, Camille; Pedersen, J.C.; Sreevatsan, Srinand; Ramey, Andy M.; Dugan, Vivien G.; Halpin, R.A.; Ferro, Paul A.; Lupiani, B.; Enomoto, Shinichiro; Poulson, Rebecca L.; Smeltzer, M.; Cardona, Carol J.; Tompkins, S.; Wentworth, D.E.; Stallknecht, D.E.; Brown, J.

2015-01-01

Introductions of H7 Influenza A virus (IAV) from wild birds into poultry have been documented worldwide, resulting in varying degrees of morbidity and mortality. H7 IAV infection in domestic poultry has served as a source of human infection and disease. We report the detection of H7N9 subtype IAV in Minnesota turkey farms during 2009 and 2011. The full-genome was sequenced from eight isolates as well as the hemagglutinin (HA) and neuraminidase (NA) gene segments of H7 and N9 virus subtypes for 108 isolates from North American wild birds between 1986 and 2012. Through maximum likelihood and coalescent phylogenetic analyses, we identified the recent H7 and N9 IAV ancestors of the turkey-origin H7N9 IAV, estimated the time and geographic origin of the ancestral viruses, and determined the relatedness between the 2009 and the 2011 turkey-origin H7N9 IAV. Analyses supported that the 2009 and the 2011 viruses were distantly related genetically, suggesting that the two outbreaks arose from independent introduction events from wild birds. Our findings further support that the 2011 MN turkey-origin H7N9 virus was closely related to H7N9 IAV isolated in poultry in Nebraska during the same year. Although the precise origin of the wild-bird donor of the turkey-origin H7N9 IAV could not be determined, our findings suggest that, for both the NA and HA gene segments, the MN turkey-origin H7N9 viruses were related to viruses circulating in wild birds between 2006 and 2011 in the Mississippi flyway.

Genesis of avian influenza H9N2 in Bangladesh.

PubMed

Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2014-12-01

Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011-2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans.

Genesis of avian influenza H9N2 in Bangladesh

PubMed Central

Shanmuganatham, Karthik; Feeroz, Mohammed M; Jones-Engel, Lisa; Walker, David; Alam, SMRabiul; Hasan, MKamrul; McKenzie, Pamela; Krauss, Scott; Webby, Richard J; Webster, Robert G

2014-01-01

Avian influenza subtype H9N2 is endemic in many bird species in Asia and the Middle East and has contributed to the genesis of H5N1, H7N9 and H10N8, which are potential pandemic threats. H9N2 viruses that have spread to Bangladesh have acquired multiple gene segments from highly pathogenic (HP) H7N3 viruses that are presumably in Pakistan and currently cocirculate with HP H5N1. However, the source and geographic origin of these H9N2 viruses are not clear. We characterized the complete genetic sequences of 37 Bangladeshi H9N2 viruses isolated in 2011–2013 and investigated their inter- and intrasubtypic genetic diversities by tracing their genesis in relationship to other H9N2 viruses isolated from neighboring countries. H9N2 viruses in Bangladesh are homogenous with several mammalian host-specific markers and are a new H9N2 sublineage wherein the hemagglutinin (HA) gene is derived from an Iranian H9N2 lineage (Mideast_B Iran), the neuraminidase (NA) and polymerase basic 2 (PB2) genes are from Dubai H9N2 (Mideast_C Dubai), and the non-structural protein (NS), nucleoprotein (NP), matrix protein (MP), polymerase acidic (PA) and polymerase basic 1 (PB1) genes are from HP H7N3 originating from Pakistan. Different H9N2 genotypes that were replaced in 2006 and 2009 by other reassortants have been detected in Bangladesh. Phylogenetic and molecular analyses suggest that the current genotype descended from the prototypical H9N2 lineage (G1), which circulated in poultry in China during the late 1990s and came to Bangladesh via the poultry trade within the Middle East, and that this genotype subsequently reassorted with H7N3 and H9N2 lineages from Pakistan and spread throughout India. Thus, continual surveillance of Bangladeshi HP H5N1, H7N3 and H9N2 is warranted to identify further evolution and adaptation to humans. PMID:26038507

Infectivity and Transmissibility of Avian H9N2 Influenza Viruses in Pigs

PubMed Central

Wang, Jia; Wu, Maocai; Hong, Wenshan; Fan, Xiaohui; Chen, Rirong; Zheng, Zuoyi; Zeng, Yu; Huang, Ren; Zhang, Yu; Lam, Tommy Tsan-Yuk; Smith, David K.

2016-01-01

ABSTRACT The H9N2 influenza viruses that are enzootic in terrestrial poultry in China pose a persistent pandemic threat to humans. To investigate whether the continuous circulation and adaptation of these viruses in terrestrial poultry increased their infectivity to pigs, we conducted a serological survey in pig herds with H9N2 viruses selected from the aquatic avian gene pool (Y439 lineage) and the enzootic terrestrial poultry viruses (G1 and Y280 lineages). We also compared the infectivity and transmissibility of these viruses in pigs. It was found that more than 15% of the pigs sampled from 2010 to 2012 in southern China were seropositive to either G1 or Y280 lineage viruses, but none of the sera were positive to the H9 viruses from the Y439 lineage. Viruses of the G1 and Y280 lineages were able to infect experimental pigs, with detectable nasal shedding of the viruses and seroconversion, whereas viruses of the Y439 lineage did not cause a productive infection in pigs. Thus, adaptation and prevalence in terrestrial poultry could lead to interspecies transmission of H9N2 viruses from birds to pigs. Although H9N2 viruses do not appear to be continuously transmissible among pigs, repeated introductions of H9 viruses to pigs naturally increase the risk of generating mammalian-adapted or reassorted variants that are potentially infectious to humans. This study highlights the importance of monitoring the activity of H9N2 viruses in terrestrial poultry and pigs. IMPORTANCE H9N2 subtype of influenza viruses has repeatedly been introduced into mammalian hosts, including humans and pigs, so awareness of their activity and evolution is important for influenza pandemic preparedness. However, since H9N2 viruses usually cause mild or even asymptomatic infections in mammalian hosts, they may be overlooked in influenza surveillance. Here, we found that the H9N2 viruses established in terrestrial poultry had higher infectivity in pigs than those from aquatic birds, which

Infectivity and Transmissibility of Avian H9N2 Influenza Viruses in Pigs.

PubMed

Wang, Jia; Wu, Maocai; Hong, Wenshan; Fan, Xiaohui; Chen, Rirong; Zheng, Zuoyi; Zeng, Yu; Huang, Ren; Zhang, Yu; Lam, Tommy Tsan-Yuk; Smith, David K; Zhu, Huachen; Guan, Yi

2016-01-13

The H9N2 influenza viruses that are enzootic in terrestrial poultry in China pose a persistent pandemic threat to humans. To investigate whether the continuous circulation and adaptation of these viruses in terrestrial poultry increased their infectivity to pigs, we conducted a serological survey in pig herds with H9N2 viruses selected from the aquatic avian gene pool (Y439 lineage) and the enzootic terrestrial poultry viruses (G1 and Y280 lineages). We also compared the infectivity and transmissibility of these viruses in pigs. It was found that more than 15% of the pigs sampled from 2010 to 2012 in southern China were seropositive to either G1 or Y280 lineage viruses, but none of the sera were positive to the H9 viruses from the Y439 lineage. Viruses of the G1 and Y280 lineages were able to infect experimental pigs, with detectable nasal shedding of the viruses and seroconversion, whereas viruses of the Y439 lineage did not cause a productive infection in pigs. Thus, adaptation and prevalence in terrestrial poultry could lead to interspecies transmission of H9N2 viruses from birds to pigs. Although H9N2 viruses do not appear to be continuously transmissible among pigs, repeated introductions of H9 viruses to pigs naturally increase the risk of generating mammalian-adapted or reassorted variants that are potentially infectious to humans. This study highlights the importance of monitoring the activity of H9N2 viruses in terrestrial poultry and pigs. H9N2 subtype of influenza viruses has repeatedly been introduced into mammalian hosts, including humans and pigs, so awareness of their activity and evolution is important for influenza pandemic preparedness. However, since H9N2 viruses usually cause mild or even asymptomatic infections in mammalian hosts, they may be overlooked in influenza surveillance. Here, we found that the H9N2 viruses established in terrestrial poultry had higher infectivity in pigs than those from aquatic birds, which suggests that adaptation of

The non-structural (NS) gene segment of H9N2 influenza virus isolated from backyard poultry in Pakistan reveals strong genetic and functional similarities to the NS gene of highly pathogenic H5N1

PubMed Central

Munir, Muhammad; Zohari, Siamak; Iqbal, Munir; Abbas, Muhammad; Perez, Daniel Roberto; Berg, Mikael

2013-01-01

Apart from natural reassortment, co-circulation of different avian influenza virus strains in poultry populations can lead to generation of novel variants and reassortant viruses. In this report, we studied the genetics and functions of a reassorted non-structural gene (NS) of H9N2 influenza virus collected from back yard poultry (BYP) flock. Phylogenetic reconstruction based on hemagglutinin and neuraminidase genes indicates that an isolate from BYP belongs to H9N2. However, the NS gene-segment of this isolate cluster into genotype Z, clade 2.2 of the highly pathogenic H5N1. The NS gene plays essential roles in the host-adaptation, cell-tropism, and virulence of influenza viruses. However, such interpretations have not been investigated in naturally recombinant H9N2 viruses. Therefore, we compared the NS1 protein of H9N2 (H9N2/NS1) and highly pathogenic H5N1 (H5N1/NS1) in parallel for their abilities to regulate different signaling pathways, and investigated the molecular mechanisms of IFN-β production in human, avian, and mink lung cells. We found that H9N2/NS1 and H5N1/NS1 are comparably similar in inhibiting TNF-α induced nuclear factor κB and double stranded RNA induced activator protein 1 and interferon regulatory factor 3 transcription factors. Thus, the production of IFN-β was inhibited equally by both NS1s as demonstrated by IFN stimulatory response element and IFN-β promoter activation. Moreover, both NS1s predominantly localized in the nucleus when transfected to human A549 cells. This study therefore suggests the possible increased virulence of natural reassortant viruses for their efficient invasion of host immune responses, and proposes that these should not be overlooked for their epizootic and zoonotic potential. PMID:23959028

The molecular characteristics of avian influenza viruses (H9N2) derived from air samples in live poultry markets.

PubMed

Wu, Yanheng; Lin, Jinsi; Yang, Shuhuan; Xie, Ying; Wang, Man; Chen, Xueqin; Zhu, Yayang; Luo, Le; Shi, Wuyang

2018-06-01

To study the molecular characteristics of H9N2-subtype avian influenza viruses (AIVs) isolated from air samples collected in live poultry markets (LPMs) and explore their sequence identities with AIVs that caused human infection. Weekly surveillance of H9N2-subtype AIVs in the air of LPMs was conducted from 2015 to 2016. H9-positive samples were isolated from chicken embryos. Whole genome sequences of the isolated AIVs were obtained through high-throughput sequencing. Phylogenetic analysis and key loci variations of the sequences were further analyzed. A total of 327 aerosol samples were collected from LPMs. Nine samples were positive for H9-subtype AIVs based on quantitative real-time reverse transcription polymerase chain reaction (qRRT-PCR). According to the whole genome sequence analysis and phylogenetic analysis, except for the A/Environment/Zhongshan/ZS201505/2015 (ZS201505) strain, 8 gene segments of 8 aerosol H9N2 isolates and 2 H9N2 human isolates in 2015 were located in the same clade. Among key loci variations, except for the ZS201505 strain, H9N2-subtype AIVs had no mutations in eight receptor binding sites of hemagglutinin (HA), and stalks of neuraminidase (NA) proteins exhibited a deletion site of three bases. The PA gene of ZS201503 and ZS201602 exhibited an L336M mutation. The N30D and T215A mutations in the M1 gene and amino acid residues L89V in PB2, P42S in NS1 and S31N in M2 were retained in these 9 strains of H9N2 isolates, which could enhance the virus's virulence. Live H9N2 AIVs survived in the aerosol of LPMs in Zhongshan City. The aerosol viruses had a close evolutionary relationship with human epidemic strains, indicating that there might be a risk of AIV transmission from polluted aerosols in LPMs to humans. Mutations in H9N2-subtype AIVs isolated from air samples collected from LPMs suggested their pathogenicity was enhanced to infect humans. Copyright © 2018. Published by Elsevier B.V.

Molecular Mechanism of the Airborne Transmissibility of H9N2 Avian Influenza A Viruses in Chickens

PubMed Central

Zhong, Lei; Wang, Xiaoquan; Li, Qunhui; Liu, Dong; Chen, Hongzhi; Zhao, Mingjun; Gu, Xiaobing; He, Liang; Liu, Xiaowen; Gu, Min; Peng, Daxin

2014-01-01

ABSTRACT H9N2 avian influenza virus has been prevalent in poultry in many parts of the world since the 1990s and occasionally crosses the host barrier, transmitting to mammals, including humans. In recent years, these viruses have contributed genes to H5N1 and H7N9 influenza viruses, threatening public health. To explore the molecular mechanism for the airborne transmission of H9N2 virus, we compared two genetically close strains isolated from chickens in 2001, A/chicken/Shanghai/7/2001(SH7) and A/chicken/Shanghai/14/2001 (SH14). SH7 is airborne transmissible between chickens, whereas SH14 is not. We used reverse genetics and gene swapping to derive recombinant SH7 (rSH7), rSH14, and a panel of reassortant viruses. Among the reassortant viruses, we identified segments HA and PA as governing the airborne transmission among chickens. In addition, the NP and NS genes also contributed to a lesser extent. Furthermore, the mutational analyses showed the transmissibility phenotype predominantly mapped to the HA and PA genes, with HA-K363 and PA-L672 being important for airborne transmissibility among chickens. In addition, the viral infectivity and acid stability are related to the airborne transmissibility. Importantly, airborne transmission studies of 18 arbitrarily chosen H9N2 viruses from our collections confirmed the importance of both 363K in HA and 672L in PA in determining their levels of transmissibility. Our finding elucidates the genetic contributions to H9N2 transmissibility in chickens and highlights the importance of their prevalence in poultry. IMPORTANCE Our study investigates the airborne transmissibility of H9N2 viruses in chickens and the subsequent epidemic. H9N2 virus is the donor for several prevalent reassortant influenza viruses, such as H7N9/2013 and the H5N1 viruses. Poultry as the reservoir hosts of influenza virus is closely associated with human society. Airborne transmission is an efficient pathway for influenza virus transmission among

Genetic and biological characterization of three poultry-origin H5N6 avian influenza viruses with all internal genes from genotype S H9N2 viruses.

PubMed

Liu, Kaituo; Gu, Min; Hu, Shunlin; Gao, Ruyi; Li, Juan; Shi, Liwei; Sun, Wenqi; Liu, Dong; Gao, Zhao; Xu, Xiulong; Hu, Jiao; Wang, Xiaoquan; Liu, Xiaowen; Chen, Sujuan; Peng, Daxin; Jiao, Xinan; Liu, Xiufan

2018-04-01

During surveillance for avian influenza viruses, three H5N6 viruses were isolated in chickens obtained from live bird markets in eastern China, between January 2015 and April 2016. Sequence analysis revealed a high genomic homology between these poultry isolates and recent human H5N6 variants whose internal genes were derived from genotype S H9N2 avian influenza viruses. Glycan binding assays revealed that all avian H5N6 viruses were capable of binding to both human-type SAα-2,6Gal receptors and avian-type SAα-2,3Gal receptors. Their biological characteristics were further studied in BALB/c mice, specific-pathogen-free chickens, and mallard ducks. All three isolates had low pathogenicity in mice but were highly pathogenic to chickens, as evidenced by 100% mortality 36-120 hours post infection at a low dose of 10 3.0 EID 50 and through effective contact transmission. Moreover, all three poultry H5N6 isolates caused asymptomatic infections in ducks, which may serve as a reservoir host for their maintenance and dissemination; these migrating waterfowl could cause a potential global pandemic. Our study suggests that continuous epidemiological surveillance in poultry should be implemented for the early prevention of future influenza outbreaks.

Efficacy of Live-Attenuated H9N2 Influenza Vaccine Candidates Containing NS1 Truncations against H9N2 Avian Influenza Viruses.

PubMed

Chen, Sujuan; Zhu, Yinbiao; Yang, Da; Yang, Yang; Shi, Shaohua; Qin, Tao; Peng, Daxin; Liu, Xiufan

2017-01-01

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.

Genetic characterization of H1N2 swine influenza virus isolated in China and its pathogenesis and inflammatory responses in mice.

PubMed

Zhang, Yan; Wang, Nan; Cao, Jiyue; Chen, Huanchun; Jin, Meilin; Zhou, Hongbo

2013-09-01

In 2009, two H1N2 influenza viruses were isolated from trachea swabs of pigs in Hubei in China. We compared these sequences with the other 18 complete genome sequences of swine H1N2 isolates from China during 2004 to 2010 and undertook extensive analysis of their evolutionary patterns. Six different genotypes - two reassortants between triple reassortant (TR) H3N2 and classical swine (CS) H1N1 virus, three reassortants between TR H1N2, Eurasian avian-like H1N1 swine virus and H9N2 swine virus, and one reassortant between H1N1, H3N2 human virus and CS H1N1 virus - were observed in these 20 swine H1N2 isolates. The TR H1N2 swine virus is the predominant genotype, and the two Hubei H1N2 isolates were located in this cluster. We also used a mouse model to examine the pathogenesis and inflammatory responses of the two isolates. The isolates replicated efficiently in the lung, and exhibited a strong inflammatory response, serious pathological changes and mortality in infected mice. Given the role that swine can play as putative "genetic mixing vessels" and the observed transmission of TR H1N2 in ferrets, H1N2 influenza surveillance in pigs should be increased to minimize the potential threat to public health.

The comparison of pathology in ferrets infected by H9N2 avian influenza viruses with different genomic features.

PubMed

Gao, Rongbao; Bai, Tian; Li, Xiaodan; Xiong, Ying; Huang, Yiwei; Pan, Ming; Zhang, Ye; Bo, Hong; Zou, Shumei; Shu, Yuelong

2016-01-15

H9N2 avian influenza virus circulates widely in poultry and has been responsible for sporadic human infections in several regions. Few studies have been conducted on the pathogenicity of H9N2 AIV isolates that have different genomic features. We compared the pathology induced by a novel reassortant H9N2 virus and two currently circulating H9N2 viruses that have different genomic features in ferrets. The results showed that the three viruses can induce infections with various amounts of viral shedding in ferrets. The novel H9N2 induced respiratory infection, but no pathological lesions were observed in lung tissues. The other two viruses induced mild to intermediate pathological lesions in lung tissues, although the clinical signs presented mildly in ferrets. The pathological lesions presented a diversity consistent with viral replication in ferrets. Copyright © 2015 Elsevier Inc. All rights reserved.

Effect of serial pig passages on the adaptation of an avian H9N2 influenza virus to swine.

PubMed

Mancera Gracia, Jose Carlos; Van den Hoecke, Silvie; Saelens, Xavier; Van Reeth, Kristien

2017-01-01

H9N2 avian influenza viruses are endemic in poultry in Asia and the Middle East. These viruses sporadically cause dead-end infections in pigs and humans raising concerns about their potential to adapt to mammals or reassort with human or swine influenza viruses. We performed ten serial passages with an avian H9N2 virus (A/quail/Hong Kong/G1/1997) in influenza naïve pigs to assess the potential of this virus to adapt to swine. Virus replication in the entire respiratory tract and nasal virus excretion were examined after each passage and we deep sequenced viral genomic RNA of the parental and passage four H9N2 virus isolated from the nasal mucosa and lung. The parental H9N2 virus caused a productive infection in pigs with a predominant tropism for the nasal mucosa, whereas only 50% lung samples were virus-positive. In contrast, inoculation of pigs with passage four virus resulted in viral replication in the entire respiratory tract. Subsequent passages were associated with reduced virus replication in the lungs and infectious virus was no longer detectable in the upper and lower respiratory tract of inoculated pigs at passage ten. The broader tissue tropism after four passages was associated with an amino acid residue substitution at position 225, within the receptor-binding site of the hemagglutinin. We also compared the parental H9N2, passage four H9N2 and the 2009 pandemic H1N1 (pH1N1) virus in a direct contact transmission experiment. Whereas only one out of six contact pigs showed nasal virus excretion of the wild-type H9N2 for more than four days, all six contact animals shed the passage four H9N2 virus. Nevertheless, the amount of excreted virus was significantly lower when compared to that of the pH1N1, which readily transmitted and replicated in all six contact animals. Our data demonstrate that serial passaging of H9N2 virus in pigs enhances its replication and transmissibility. However, full adaptation of an avian H9N2 virus to pigs likely requires an

Effect of serial pig passages on the adaptation of an avian H9N2 influenza virus to swine

PubMed Central

Van den Hoecke, Silvie; Saelens, Xavier; Van Reeth, Kristien

2017-01-01

H9N2 avian influenza viruses are endemic in poultry in Asia and the Middle East. These viruses sporadically cause dead-end infections in pigs and humans raising concerns about their potential to adapt to mammals or reassort with human or swine influenza viruses. We performed ten serial passages with an avian H9N2 virus (A/quail/Hong Kong/G1/1997) in influenza naïve pigs to assess the potential of this virus to adapt to swine. Virus replication in the entire respiratory tract and nasal virus excretion were examined after each passage and we deep sequenced viral genomic RNA of the parental and passage four H9N2 virus isolated from the nasal mucosa and lung. The parental H9N2 virus caused a productive infection in pigs with a predominant tropism for the nasal mucosa, whereas only 50% lung samples were virus-positive. In contrast, inoculation of pigs with passage four virus resulted in viral replication in the entire respiratory tract. Subsequent passages were associated with reduced virus replication in the lungs and infectious virus was no longer detectable in the upper and lower respiratory tract of inoculated pigs at passage ten. The broader tissue tropism after four passages was associated with an amino acid residue substitution at position 225, within the receptor-binding site of the hemagglutinin. We also compared the parental H9N2, passage four H9N2 and the 2009 pandemic H1N1 (pH1N1) virus in a direct contact transmission experiment. Whereas only one out of six contact pigs showed nasal virus excretion of the wild-type H9N2 for more than four days, all six contact animals shed the passage four H9N2 virus. Nevertheless, the amount of excreted virus was significantly lower when compared to that of the pH1N1, which readily transmitted and replicated in all six contact animals. Our data demonstrate that serial passaging of H9N2 virus in pigs enhances its replication and transmissibility. However, full adaptation of an avian H9N2 virus to pigs likely requires an

The first Swedish H1N2 swine influenza virus isolate represents an uncommon reassortant.

PubMed

Bálint, Adám; Metreveli, Giorgi; Widén, Frederik; Zohari, Siamak; Berg, Mikael; Isaksson, Mats; Renström, Lena Hm; Wallgren, Per; Belák, Sándor; Segall, Thomas; Kiss, István

2009-10-28

The European swine influenza viruses (SIVs) show considerable diversity comprising different types of H1N1, H3N2, and H1N2 strains. The intensifying full genome sequencing efforts reveal further reassortants within these subtypes. Here we report the identification of an uncommon reassortant variant of H1N2 subtype influenza virus isolated from a pig in a multisite herd where H1N2 swine influenza was diagnosed for the first time in Sweden during the winter of 2008-2009. The majority of the European H1N2 swine influenza viruses described so far possess haemagglutinin (HA) of the human-like H1N2 SIV viruses and the neuraminidase (NA) of either the European H1N2 or H3N2 SIV-like viruses. The Swedish isolate has an avian-like SIV HA and a H3N2 SIV-like NA, which is phylogenetically more closely related to H3N2 SIV NAs from isolates collected in the early '80s than to the NA of H3N2 origin of the H1N2 viruses isolated during the last decade, as depicted by some German strains, indicative of independent acquisition of the NA genes for these two types of reassortants. The internal genes proved to be entirely of avian-like SIV H1N1 origin. The prevalence of this SIV variant in pig populations needs to be determined, as well as the suitability of the routinely used laboratory reagents to analyze this strain.The description of this H1N2 SIV adds further information to influenza epidemiology and supports the necessity of surveillance for influenza viruses in pigs.

Molecular mechanism of the airborne transmissibility of H9N2 avian influenza A viruses in chickens.

PubMed

Zhong, Lei; Wang, Xiaoquan; Li, Qunhui; Liu, Dong; Chen, Hongzhi; Zhao, Mingjun; Gu, Xiaobing; He, Liang; Liu, Xiaowen; Gu, Min; Peng, Daxin; Liu, Xiufan

2014-09-01

H9N2 avian influenza virus has been prevalent in poultry in many parts of the world since the 1990s and occasionally crosses the host barrier, transmitting to mammals, including humans. In recent years, these viruses have contributed genes to H5N1 and H7N9 influenza viruses, threatening public health. To explore the molecular mechanism for the airborne transmission of H9N2 virus, we compared two genetically close strains isolated from chickens in 2001, A/chicken/Shanghai/7/2001(SH7) and A/chicken/Shanghai/14/2001 (SH14). SH7 is airborne transmissible between chickens, whereas SH14 is not. We used reverse genetics and gene swapping to derive recombinant SH7 (rSH7), rSH14, and a panel of reassortant viruses. Among the reassortant viruses, we identified segments HA and PA as governing the airborne transmission among chickens. In addition, the NP and NS genes also contributed to a lesser extent. Furthermore, the mutational analyses showed the transmissibility phenotype predominantly mapped to the HA and PA genes, with HA-K363 and PA-L672 being important for airborne transmissibility among chickens. In addition, the viral infectivity and acid stability are related to the airborne transmissibility. Importantly, airborne transmission studies of 18 arbitrarily chosen H9N2 viruses from our collections confirmed the importance of both 363K in HA and 672L in PA in determining their levels of transmissibility. Our finding elucidates the genetic contributions to H9N2 transmissibility in chickens and highlights the importance of their prevalence in poultry. Our study investigates the airborne transmissibility of H9N2 viruses in chickens and the subsequent epidemic. H9N2 virus is the donor for several prevalent reassortant influenza viruses, such as H7N9/2013 and the H5N1 viruses. Poultry as the reservoir hosts of influenza virus is closely associated with human society. Airborne transmission is an efficient pathway for influenza virus transmission among flocks and individuals

Vaccine Efficacy of Inactivated, Chimeric Hemagglutinin H9/H5N2 Avian Influenza Virus and Its Suitability for the Marker Vaccine Strategy

PubMed Central

Kim, Se Mi; Kim, Young-Il; Park, Su-Jin; Kim, Eun-Ha; Kwon, Hyeok-il; Si, Young-Jae; Lee, In-Won; Song, Min-Suk

2017-01-01

avian influenza viruses. IMPORTANCE Current influenza virus killed vaccines predominantly induce antihemagglutinin (anti-HA) antibodies that are commonly strain specific in that the antibodies have potent neutralizing activity against homologous strains but do not cross-react with HAs of other influenza virus subtypes. In contrast, the HA2 stalk domain is relatively well conserved among subtypes, and recently, broadly neutralizing antibodies against this domain have been isolated. Therefore, in light of the need for a vaccine strain that applies the DIVA strategy utilizing an HI assay and induces broad cross-protection against H5N1 and H9N2 viruses, we generated a novel chimeric H9/H5N1 virus that expresses the entire HA1 portion from the H9N2 virus and the HA2 region of the heterosubtypic H5N8 virus. The chimeric H9/H5N2 recombinant vaccine protected immunized hosts against lethal challenge with H9N2 and HPAI H5N1 viruses with significantly attenuated virus shedding in immunized hosts. Therefore, this chimeric vaccine is suitable as a DIVA vaccine against H5 avian influenza viruses. PMID:28077631

Comparative study of the hemagglutinin and neuraminidase genes of influenza A virus H3N2, H9N2, and H5N1 subtypes using bioinformatics techniques.

PubMed

Ahn, Insung; Son, Hyeon S

2007-07-01

To investigate the genomic patterns of influenza A virus subtypes, such as H3N2, H9N2, and H5N1, we collected 1842 sequences of the hemagglutinin and neuraminidase genes from the NCBI database and parsed them into 7 categories: accession number, host species, sampling year, country, subtype, gene name, and sequence. The sequences that were isolated from the human, avian, and swine populations were extracted and stored in a MySQL database for intensive analysis. The GC content and relative synonymous codon usage (RSCU) values were calculated using JAVA codes. As a result, correspondence analysis of the RSCU values yielded the unique codon usage pattern (CUP) of each subtype and revealed no extreme differences among the human, avian, and swine isolates. H5N1 subtype viruses exhibited little variation in CUPs compared with other subtypes, suggesting that the H5N1 CUP has not yet undergone significant changes within each host species. Moreover, some observations may be relevant to CUP variation that has occurred over time among the H3N2 subtype viruses isolated from humans. All the sequences were divided into 3 groups over time, and each group seemed to have preferred synonymous codon patterns for each amino acid, especially for arginine, glycine, leucine, and valine. The bioinformatics technique we introduce in this study may be useful in predicting the evolutionary patterns of pandemic viruses.

Multiple introductions of a reassortant H5N1 avian influenza virus of clade 2.3.2.1c with PB2 gene of H9N2 subtype into Indian poultry.

PubMed

Tosh, Chakradhar; Nagarajan, Shanmugasundaram; Kumar, Manoj; Murugkar, Harshad V; Venkatesh, Govindarajulu; Shukla, Shweta; Mishra, Amit; Mishra, Pranav; Agarwal, Sonam; Singh, Bharati; Dubey, Prashant; Tripathi, Sushil; Kulkarni, Diwakar D

2016-09-01

Highly pathogenic avian influenza (HPAI) H5N1 viruses are a threat to poultry in Asia, Europe, Africa and North America. Here, we report isolation and characterization of H5N1 viruses isolated from ducks and turkeys in Kerala, Chandigarh and Uttar Pradesh, India between November 2014 and March 2015. Genetic and phylogenetic analyses of haemagglutinin gene identified that the virus belonged to a new clade 2.3.2.1c which has not been detected earlier in Indian poultry. The virus possessed molecular signature for high pathogenicity to chickens, which was corroborated by intravenous pathogenicity index of 2.96. The virus was a reassortant which derives its PB2 gene from H9N2 virus isolated in China during 2007-2013. However, the neuraminidase and internal genes are of H5N1 subtype. Phylogenetic and network analysis revealed that after detection in China in 2013/2014, the virus moved to Europe, West Africa and other Asian countries including India. The analyses further indicated multiple introductions of H5N1 virus in Indian poultry and internal spread in Kerala. One of the outbreaks in ducks in Kerala is linked to the H5N1 virus isolated from wild birds in Dubai suggesting movement of virus probably through migration of wild birds. However, the outbreaks in ducks in Chandigarh and Uttar Pradesh were from an unknown source in Asia which also contributed gene pools to the outbreaks in Europe and West Africa. The widespread incidence of the novel H5N1 HPAI is similar to the spread of clade 2.2 ("Qinghai-like") virus in 2005, and should be monitored to avoid threat to animal and public health. Copyright © 2016 Elsevier B.V. All rights reserved.

Complete genome sequence of a novel H9N2 subtype influenza virus FJG9 strain in China reveals a natural reassortant event.

PubMed

Xie, Qingmei; Yan, Zhuanqiang; Ji, Jun; Zhang, Huanmin; Liu, Jun; Sun, Yue; Li, Guangwei; Chen, Feng; Xue, Chunyi; Ma, Jingyun; Bee, Yingzuo

2012-09-01

A/chicken/FJ/G9/09 (FJ/G9) is an H9N2 subtype avian influenza virus (H9N2 AIV) strain causing high morbidity that was isolated from broilers in Fujian Province of China in 2009. FJ/G9 has been used as the vaccine strain against H9N2 AIV infection in Fujian Province of China. Here, we report the complete genome sequence of FJ/G9 with natural six-way reassortment, which is the most complex genotype strain in China and even in the world so far. The present findings will aid in understanding the complexity and diversity of H9N2 subtype avian influenza virus.

Different neuraminidase inhibitor susceptibilities of human H1N1, H1N2, and H3N2 influenza A viruses isolated in Germany from 2001 to 2005/2006.

PubMed

Bauer, Katja; Richter, Martina; Wutzler, Peter; Schmidtke, Michaela

2009-04-01

In the flu season 2005/2006 amantadine-resistant human influenza A viruses (FLUAV) of subtype H3N2 circulated in Germany. This raises questions on the neuraminidase inhibitor (NAI) susceptibility of FLUAV. To get an answer, chemiluminescence-based neuraminidase inhibition assays were performed with 51 H1N1, H1N2, and H3N2 FLUAV isolated in Germany from 2001 to 2005/2006. According to the mean IC(50) values (0.38-0.91 nM for oseltamivir and 0.76-1.13 nM for zanamivir) most H1N1 and H3N2 FLUAV were NAI-susceptible. But, about four times higher zanamivir concentrations were necessary to inhibit neuraminidase activity of H1N2 viruses. Two H1N1 isolates were less susceptible to both drugs in NA inhibition as well as virus yield reduction assays. Results from sequence analysis of viral hemagglutinin and neuraminidase genes and evolutionary analysis of N2 gene revealed (i) different subclades for N2 in H1N2 and H3N2 FLUAV that could explain the differences in zanamivir susceptibility among these viruses and (ii) specific amino acid substitutions in the neuraminidase segment of the two less NAI-susceptible H1N1 isolates. One H3N2 was isolate proved to be a mixture of a NA deletion mutant and full-length NA viruses.

Complete genome sequence of a novel H9N2 subtype influenza virus FJG9 strain in china reveals a natural reassortant event

USDA-ARS?s Scientific Manuscript database

A Chicken/FJ/G9/09 (FJ/G9) is an H9N2 subtype strain of avian influenza virus (H9N2 AIV) strain causing high morbidity, that was isolated from broilers in Fujian province, China, in 2009. The FJ/G9 has been used as the vaccine strain against H9N2 AIV infection in Fujian Province of China. Here, we r...

Novel reassortant influenza A(H1N2) virus derived from A(H1N1)pdm09 virus isolated from swine, Japan, 2012.

PubMed

Kobayashi, Miho; Takayama, Ikuyo; Kageyama, Tsutomu; Tsukagoshi, Hiroyuki; Saitoh, Mika; Ishioka, Taisei; Yokota, Yoko; Kimura, Hirokazu; Tashiro, Masato; Kozawa, Kunihisa

2013-12-01

We isolated a novel influenza virus A(H1N2) strain from a pig on January 13, 2012, in Gunma Prefecture, Japan. Phylogenetic analysis showed that the strain was a novel type of double-reassortant virus derived from the swine influenza virus strains H1N1pdm09 and H1N2, which were prevalent in Gunma at that time.

Development of a dual-protective live attenuated vaccine against H5N1 and H9N2 avian influenza viruses by modifying the NS1 gene.

PubMed

Choi, Eun-hye; Song, Min-Suk; Park, Su-Jin; Pascua, Philippe Noriel Q; Baek, Yun Hee; Kwon, Hyeok-il; Kim, Eun-Ha; Kim, Semi; Jang, Hyung-Kwan; Poo, Haryoung; Kim, Chul-Joong; Choi, Young Ki

2015-07-01

An increasing number of outbreaks of avian influenza H5N1 and H9N2 viruses in poultry have caused serious economic losses and raised concerns for human health due to the risk of zoonotic transmission. However, licensed H5N1 and H9N2 vaccines for animals and humans have not been developed. Thus, to develop a dual H5N1 and H9N2 live-attenuated influenza vaccine (LAIV), the HA and NA genes from a virulent mouse-adapted avian H5N2 (A/WB/Korea/ma81/06) virus and a recently isolated chicken H9N2 (A/CK/Korea/116/06) virus, respectively, were introduced into the A/Puerto Rico/8/34 backbone expressing truncated NS1 proteins (NS1-73, NS1-86, NS1-101, NS1-122) but still possessing a full-length NS gene. Two H5N2/NS1-LAIV viruses (H5N2/NS1-86 and H5N2/NS1-101) were highly attenuated compared with the full-length and remaining H5N2/NS-LAIV viruses in a mouse model. Furthermore, viruses containing NS1 modifications were found to induce more IFN-β activation than viruses with full-length NS1 proteins and were correspondingly attenuated in mice. Intranasal vaccination with a single dose (10(4.0) PFU/ml) of these viruses completely protected mice from a lethal challenge with the homologous A/WB/Korea/ma81/06 (H5N2), heterologous highly pathogenic A/EM/Korea/W149/06 (H5N1), and heterosubtypic highly virulent mouse-adapted H9N2 viruses. This study clearly demonstrates that the modified H5N2/NS1-LAIV viruses attenuated through the introduction of mutations in the NS1 coding region display characteristics that are desirable for live attenuated vaccines and hold potential as vaccine candidates for mammalian hosts.

Mammalian Pathogenesis and Transmission of H7N9 Influenza Viruses from Three Waves, 2013-2015

PubMed Central

Belser, Jessica A.; Creager, Hannah M.; Sun, Xiangjie; Gustin, Kortney M.; Jones, Tara; Shieh, Wun-Ju; Maines, Taronna R.

2016-01-01

ABSTRACT Three waves of human infection with H7N9 influenza viruses have concluded to date, but only viruses within the first wave (isolated between March and September 2013) have been extensively studied in mammalian models. While second- and third-wave viruses remain closely linked phylogenetically and antigenically, even subtle molecular changes can impart critical shifts in mammalian virulence. To determine if H7N9 viruses isolated from humans during 2013 to 2015 have maintained the phenotype first identified among 2013 isolates, we assessed the ability of first-, second-, and third-wave H7N9 viruses isolated from humans to cause disease in mice and ferrets and to transmit among ferrets. Similar to first-wave viruses, H7N9 viruses from 2013 to 2015 were highly infectious in mice, with lethality comparable to that of the well-studied A/Anhui/1/2013 virus. Second- and third-wave viruses caused moderate disease in ferrets, transmitted efficiently to cohoused, naive contact animals, and demonstrated limited transmissibility by respiratory droplets. All H7N9 viruses replicated efficiently in human bronchial epithelial cells, with subtle changes in pH fusion threshold identified between H7N9 viruses examined. Our results indicate that despite increased genetic diversity and geographical distribution since their initial detection in 2013, H7N9 viruses have maintained a pathogenic phenotype in mammals and continue to represent an immediate threat to public health. IMPORTANCE H7N9 influenza viruses, first isolated in 2013, continue to cause human infection and represent an ongoing public health threat. Now entering the fourth wave of human infection, H7N9 viruses continue to exhibit genetic diversity in avian hosts, necessitating continuous efforts to monitor their pandemic potential. However, viruses isolated post-2013 have not been extensively studied, limiting our understanding of potential changes in virus-host adaptation. In order to ensure that current research

Novel Reassortant Influenza A(H1N2) Virus Derived from A(H1N1)pdm09 Virus Isolated from Swine, Japan, 2012

PubMed Central

Kobayashi, Miho; Takayama, Ikuyo; Kageyama, Tsutomu; Tsukagoshi, Hiroyuki; Saitoh, Mika; Ishioka, Taisei; Yokota, Yoko; Kimura, Hirokazu; Tashiro, Masato

2013-01-01

We isolated a novel influenza virus A(H1N2) strain from a pig on January 13, 2012, in Gunma Prefecture, Japan. Phylogenetic analysis showed that the strain was a novel type of double-reassortant virus derived from the swine influenza virus strains H1N1pdm09 and H1N2, which were prevalent in Gunma at that time. PMID:24274745

Novel H7N2 and H5N6 Avian Influenza A Viruses in Sentinel Chickens: A Sentinel Chicken Surveillance Study.

PubMed

Zhao, Teng; Qian, Yan-Hua; Chen, Shan-Hui; Wang, Guo-Lin; Wu, Meng-Na; Huang, Yong; Ma, Guang-Yuan; Fang, Li-Qun; Gray, Gregory C; Lu, Bing; Tong, Yi-Gang; Ma, Mai-Juan; Cao, Wu-Chun

2016-01-01

In 2014, a sentinel chicken surveillance for avian influenza viruses was conducted in aquatic bird habitat near Wuxi City, Jiangsu Province, China. Two H7N2, one H5N6, and two H9N2 viruses were isolated. Sequence analysis revealed that the H7N2 virus is a novel reassortant of H7N9 and H9N2 viruses and H5N6 virus is a reassortant of H5N1 clade 2.3.4 and H6N6 viruses. Substitutions V186 and L226 (H3 numbering) in the hemagglutinin (HA) gene protein was found in two H7N2 viruses but not in the H5N6 virus. Two A138 and A160 mutations were identified in the HA gene protein of all three viruses but a P128 mutation was only observed in the H5N6 virus. A deletion of 3 and 11 amino acids in the neuraminidase stalk region was found in two H7N2 and H5N6 viruses, respectively. Moreover, a mutation of N31 in M2 protein was observed in both two H7N2 viruses. High similarity of these isolated viruses to viruses previously identified among poultry and humans, suggests that peridomestic aquatic birds may play a role in sustaining novel virus transmission. Therefore, continued surveillance is needed to monitor these avian influenza viruses in wild bird and domestic poultry that may pose a threat to poultry and human health.

Genetics and biological property analysis of Korea lineage of influenza A H9N2 viruses.

PubMed

Kang, Min; Jang, Hyung-Kwan

2017-05-01

H9N2 influenza viruses have been detected from wild and domestic avian species including chickens and ducks worldwide. Few studies have compared the biological properties of different H9N2 lineages or determined whether certain lineages might pose a higher risk to mammals, especially H9N2 viruses of Korean lineage. The objective of this study was to characterize the genetic and biological properties of 22 Korean H9N2 viruses and assess their potential risks to mammals. Their complete genomes were analyzed. Some Korean H9N2 viruses were found to carry mammalian host-specific mutations. Based on genomic diversities, these H9N2 viruses were divided into 12 genotypes. All 22 showed preferential binding to human-like receptor. Two of eight H9N2 viruses were highly lethal to mice, causing 90-100% mortality without prior adaptation and severe respiratory syndromes associated with diffuse lung injury, severe pneumonia, and alveolar damage. These findings suggest that recent Korean H9N2 viruses might have established a stable sublineage with enhanced pathogenicity to mice. Various H9N2 strains pathogenic to mice were endemic in wild bird, poultry farm, and live bird markets, suggesting that Korean H9N2 viruses could evolve to become a threat to humans. The findings emphasize the necessity of careful, continuous, and thorough surveillance paired with risk-assessment for circulating H9N2 influenza viruses. Copyright © 2017 Elsevier B.V. All rights reserved.

Genetic evolution of low pathogenecity H9N2 Avian influenza viruses in Tunisia: acquisition of new mutations

PubMed Central

2011-01-01

Background Since the end of 2009, H9N2 has emerged in Tunisia causing several epidemics in poultry industry resulting in major economic losses. To monitor variations of Influenza viruses during the outbreaks, Tunisian H9N2 virus isolates were identified and genetically characterized. Methods The genomic RNA segments of Tunisian H9N2 strains were subjected to RT-PCR amplifications followed by sequencing analysis. Results Phylogenetic analysis demonstrated that A/Ck/TUN/12/10 and A/Migratory Bird/TUN/51/10 viruses represent multiple reassortant lineages, with genes coming from Middle East strains, and share the common ancestor Qa/HK/G1/97 isolate which has contributed internal genes of H5N1 virus circulating in Asia. Some of the internal genes seemed to have undergone broad reassortments with other influenza subtypes. Deduced amino acid sequences of the hemagglutinin (HA) gene showed the presence of additional glycosylation site and Leu at position 234 indicating to binding preference to α (2, 6) sialic acid receptors, indicating their potential to directly infect humans. The Hemagglutinin cleavage site motif sequence is 333 PARSSR*GLF341 which indicates the low pathogenicity nature of the Tunisian H9N2 strains and the potential to acquire the basic amino acids required for the highly pathogenic strains. Their neuraminidase protein (NA) carried substitutions in the hemadsorption (HB) site, similar to those of other avian H9N2 viruses from Asia, Middle Eastern and human pandemic H2N2 and H3N2 that bind to α -2, 6 -linked receptors. Two avian virus-like aa at positions 661 (A) and 702 (K), similar to H5N1 strains, were identified in the polymerase (PB2) protein. Likewise, matrix (M) protein carried some substitutions which are linked with increasing replication in mammals. In addition, H9N2 strain recently circulating carried new polymorphism, "GSEV" PDZ ligand (PL) C-terminal motif in its non structural (NS) protein. Two new aa substitutions (I) and (V), that haven

Live Bird Markets of Bangladesh: H9N2 Viruses and the Near Absence of Highly Pathogenic H5N1 Influenza

PubMed Central

Negovetich, Nicholas J.; Feeroz, Mohammed M.; Jones-Engel, Lisa; Walker, David; Alam, S. M. Rabiul; Hasan, Kamrul; Seiler, Patrick; Ferguson, Angie; Friedman, Kim; Barman, Subrata; Franks, John; Turner, Jasmine; Krauss, Scott; Webby, Richard J.; Webster, Robert G.

2011-01-01

Avian influenza surveillance in Bangladesh has been passive, relying on poultry farmers to report suspected outbreaks of highly pathogenic H5N1 influenza. Here, the results of an active surveillance effort focusing on the live-bird markets are presented. Prevalence of influenza infection in the birds of the live bird markets is 23.0%, which is similar to that in poultry markets in other countries. Nearly all of the isolates (94%) were of the non-pathogenic H9N2 subtype, but viruses of the H1N2, H1N3, H3N6, H4N2, H5N1, and H10N7 subtypes were also observed. The highly pathogenic H5N1-subtype virus was observed at extremely low prevalence in the surveillance samples (0.08%), and we suggest that the current risk of infection for humans in the retail poultry markets in Bangladesh is negligible. However, the high prevalence of the H9 subtype and its potential for interaction with the highly pathogenic H5N1-subtype, i.e., reassortment and attenuation of host morbidity, highlight the importance of active surveillance of the poultry markets. PMID:21541296

Signal Immune Reactions of Macrophages Differentiated from THP-1 Monocytes to Infection with Pandemic H1N1PDM09 Virus and H5N2 and H9N2 Avian Influenza A Virus.

PubMed

Sokolova, T M; Poloskov, V V; Shuvalov, A N; Rudneva, I A; Timofeeva, T A

2018-03-01

In culture of THP-1 cells differentiated into macrophages with PMA (THP-PMA macrophages) infected with influenza viruses of subtypes H1, H5 and H9, we measured the expression of TLR7 and RIG1 receptor genes, sensors of viral RNA and ribonucleoprotein, and the levels of production of inflammatory cytokines IL-1β, TNFα, IL-10, and IFNα. The sensitivity and inflammatory response of THP-PMA macrophages to pandemic influenza A virus H1N1pdm09 and avian influenza H5N2 and H9N2 viruses correlate with the intracellular level of their viral RNA and activation of the RIG1 gene. Abortive infection is accompanied by intensive macrophage secretion of TNFα, IL-1β, and toxic factors inducing cell death. Activity of endosomal TLR7 receptor gene changed insignificantly in 24 h after infection and significantly decreased in 48 and 72 h under the action of H5N2 and H9N2, which correlated with manifestation of the cytopathogenic effect of these viruses. H5N2 and H9N2 avian viruses in THP-PMA macrophages are strong activators of the expression of the gene of the cytoplasmic RIG1 receptor 24 and 48 h after infection, and the pandemic virus H1N1pdm09 is a weak stimulator of RIG1 gene. Avian influenza H5N2 and H9N2 viruses are released by rapid induction of the inflammatory response in macrophages. At the late stages of infection, we observed a minor increase in IL-10 secretion in macrophages and, probably, the polarization of a part of the population in type M2. The studied influenza A viruses are weak inductors of IFN in THP-PMA macrophages. In the culture medium of THP-PMA macrophages infected with H9N2 and H5N2 viruses, MTT test revealed high levels of toxic factors causing the death of Caco-2 cells. In contrast to avian viruses, pandemic virus H1N1pdm09 did not induce production of toxic factors.

Dispersal of H9N2 influenza A viruses between East Asia and North America by wild birds

USGS Publications Warehouse

Ramey, Andy M.; Reeves, Andrew B.; Sonsthagen, Sarah A.; Teslaa, Joshua L.; Nashold, Sean W.; Donnelly, Tyrone F.; Casler, Bruce; Hall, Jeffrey S.

2015-01-01

Samples were collected from wild birds in western Alaska to assess dispersal of influenza A viruses between East Asia and North America. Two isolates shared nearly identical nucleotide identity at eight genomic segments with H9N2 viruses isolated from China and South Korea providing evidence for intercontinental dispersal by migratory birds.

Chlamydia psittaci infection increases mortality of avian influenza virus H9N2 by suppressing host immune response.

PubMed

Chu, Jun; Zhang, Qiang; Zhang, Tianyuan; Han, Er; Zhao, Peng; Khan, Ahrar; He, Cheng; Wu, Yongzheng

2016-07-11

Avian influenza virus subtype H9N2 (H9N2) and Chlamydia psittaci (C. psittaci) are frequently isolated in chickens with respiratory disease. However, their roles in co-infection remain unclear. We tested the hypothesis that C. psittaci enhances H9N2 infection through suppression of host immunity. Thus, 10-day-old SPF chickens were inoculated intra-tracheally with a high or low virulence C. psittaci strain, and were simultaneously vaccinated against Newcastle disease virus (NDV). Significant decreases in body weight, NDV antibodies and immune organ indices occurred in birds with the virulent C. psittaci infection, while the ratio of CD4+/CD8+ T cells increased significantly compared to that of the lower virulence strain. A second group of birds were inoculated with C. psittaci and H9N2 simultaneously (C. psittaci+H9N2), C. psittaci 3 days prior to H9N2 (C. psittaci/H9N2), or 3 days after H9N2 (H9N2/C. psittaci), C. psittaci or H9N2 alone. Survival rates were 65%, 80% and 90% in the C. psittaci/H9N2, C. psittaci+H9N2 and H9N2/C. psittaci groups, respectively and respiratory clinical signs, lower expression of pro-inflammatory cytokines and higher pathogen loads were found in both C. psittaci/H9N2 and C. psittaci+H9N2 groups. Hence, virulent C. psittaci infection suppresses immune response by inhibiting humoral responses and altering Th1/Th2 balance, increasing mortality in H9N2 infected birds.

Chlamydia psittaci infection increases mortality of avian influenza virus H9N2 by suppressing host immune response

PubMed Central

Chu, Jun; Zhang, Qiang; Zhang, Tianyuan; Han, Er; Zhao, Peng; Khan, Ahrar; He, Cheng; Wu, Yongzheng

2016-01-01

Avian influenza virus subtype H9N2 (H9N2) and Chlamydia psittaci (C. psittaci) are frequently isolated in chickens with respiratory disease. However, their roles in co-infection remain unclear. We tested the hypothesis that C. psittaci enhances H9N2 infection through suppression of host immunity. Thus, 10-day-old SPF chickens were inoculated intra-tracheally with a high or low virulence C. psittaci strain, and were simultaneously vaccinated against Newcastle disease virus (NDV). Significant decreases in body weight, NDV antibodies and immune organ indices occurred in birds with the virulent C. psittaci infection, while the ratio of CD4+/CD8+ T cells increased significantly compared to that of the lower virulence strain. A second group of birds were inoculated with C. psittaci and H9N2 simultaneously (C. psittaci+H9N2), C. psittaci 3 days prior to H9N2 (C. psittaci/H9N2), or 3 days after H9N2 (H9N2/C. psittaci), C. psittaci or H9N2 alone. Survival rates were 65%, 80% and 90% in the C. psittaci/H9N2, C. psittaci+H9N2 and H9N2/C. psittaci groups, respectively and respiratory clinical signs, lower expression of pro-inflammatory cytokines and higher pathogen loads were found in both C. psittaci/H9N2 and C. psittaci+H9N2 groups. Hence, virulent C. psittaci infection suppresses immune response by inhibiting humoral responses and altering Th1/Th2 balance, increasing mortality in H9N2 infected birds. PMID:27405059

Global genetic variation and transmission dynamics of H9N2 avian influenza virus.

PubMed

Wei, K; Li, Y

2018-04-01

The H9N2 influenza viruses are extensively circulating in the poultry population, and variable genotypes can be generated through mutation, recombination and reassortment, which may be better adapted to infect a new host, resist drug treatment or escape immune pressure. The LPAI H9N2 viruses have the potential to evolve towards high levels of virulence in human. Some studies about the regional dispersal were reported, but global dissemination and the drivers of the virus are poorly understood, particularly at the genome scale. Here, we have analysed all eight gene segments of 168 H9N2 genomes sampled randomly aiming to provide a panoramic framework for better understanding the genesis and genetic variation of the viruses, and utilized phylogeography and spatial epidemiology approaches to uncover the effects of the genetic variation, predictors and spread of H9N2 viruses. We found that more frequent reassortment events involve segments PA, NP and NS, and 21 isolates have possible mosaic structure resulting from recombination events. Estimates of gene-specific global dN/dS ratios showed that all genes were subject to purifying selection. However, a total of 13 sites were detected under positive selection by at least two of three methods, which located within segments HA, NA, M2, NS1 and PA. Additionally, we inferred that NA segment has the highest rate of nucleotide substitution, and its tMRCA estimate is the youngest than the remaining segments' inference. About the spatial history, air transportation of human was identified as the predominant driver of global viral migration using GLM analysis, and economic factors and geographical distance were the modest predictors. Higher migration rates were estimated between five pairs of regions (>0.01) indicating the frequent migration of the viruses between discrete geographical locations. Further, our Markov jumps analysis showed that viral migration is more frequent between Southern China and Northern China, and high rate

Antigenic evolution of H9N2 chicken influenza viruses isolated in China during 2009-2013 and selection of a candidate vaccine strain with broad cross-reactivity.

PubMed

Wei, Yandi; Xu, Guanlong; Zhang, Guozhong; Wen, Chu; Anwar, Furkat; Wang, Shuoguo; Lemmon, Gordon; Wang, Jinliang; Carter, Robert; Wang, Min; Sun, Honglei; Sun, Yipeng; Zhao, Jixun; Wu, Gang; Webster, Robert G; Liu, Jinhua; Pu, Juan

2016-01-01

We previously demonstrated that H9N2 subtype avian influenza viruses (AIVs) isolated from 1994 to 2008 evolved into distinct antigenic groups (C, D, and E) and then underwent antigenic drift from commercial vaccines, causing a country-wide outbreak during 2010-2013. In this study, H9N2 AIVs isolated from chickens during 2009-2013 were antigenically analyzed by performing hemagglutination inhibition and neutralization assays using a panel of polyclonal antibodies. Our findings confirmed the antigenic drift of recent H9N2 viruses from the commercial vaccine and showed that most of these antigenic variants form a novel HI antigenic group, F, with a few belonging to groups D and E. Slight antigenic variation was observed in group F viruses. Genetic analysis of amino acid sequences deduced from hemagglutinin (HA) gene sequences indicated that 9 of 15 mutations predominant in the 2009-2013 viruses can be mapped to known antigenic sites, which might be responsible for the novel antigenicity of group F. These antigenic changes make it necessary to modify the influenza vaccine to ensure efficient protection. A vaccine candidate, Ck/HeB/YT/10, was selected and provided significant protection against viruses from different antigenic groups in terms of reduction in virus shedding, suggesting broad cross-reactivity. Taken together, our results indicate that the H9N2 chicken influenza viruses in China have evolved from distinct antigenic groups into a novel group F that became dominant during the country-wide outbreak and now seems to be undergoing new antigenic divergence. Systematic surveillance and timely updating of vaccine strains are important for viral prevention and control in the future. Copyright © 2015 Elsevier B.V. All rights reserved.

Antigenic evolution of H9N2 chicken influenza viruses isolated in China during 2009–2013 and selection of a candidate vaccine strain with broad cross-reactivity

PubMed Central

Wei, Yandi; Xu, Guanlong; Zhang, Guozhong; Wen, Chu; Anwar, Furkat; Wang, Shuoguo; Lemmon, Gordon; Wang, Jinliang; Carter, Robert; Wang, Min; Sun, Honglei; Sun, Yipeng; Zhao, Jixun; Wu, Gang; Webster, Robert G.; Liu, Jinhua; Pu, Juan

2016-01-01

We previously demonstrated that H9N2 subtype avian influenza viruses (AIVs) isolated from 1994 to 2008 evolved into distinct antigenic groups (C, D, and E) and then underwent antigenic drift from commercial vaccines, causing a country-wide outbreak during 2010–2013. In this study, H9N2 AIVs isolated from chickens during 2009–2013 were antigenically analyzed by performing hemagglutination inhibition and neutralization assays using a panel of polyclonal antibodies. Our findings confirmed the antigenic drift of recent H9N2 viruses from the commercial vaccine and showed that most of these antigenic variants form a novel HI antigenic group, F, with a few belonging to groups D and E. Slight antigenic variation was observed in group F viruses. Genetic analysis of amino acid sequences deduced from hemagglutinin (HA) gene sequences indicated that 9 of 15 mutations predominant in the 2009–2013 viruses can be mapped to known antigenic sites, which might be responsible for the novel antigenicity of group F. These antigenic changes make it necessary to modify the influenza vaccine to ensure efficient protection. A vaccine candidate, Ck/HeB/YT/10, was selected and provided significant protection against viruses from different antigenic groups in terms of reduction in virus shedding, suggesting broad cross-reactivity. Taken together, our results indicate that the H9N2 chicken influenza viruses in China have evolved from distinct antigenic groups into a novel group F that became dominant during the country-wide outbreak and now seems to be undergoing new antigenic divergence. Systematic surveillance and timely updating of vaccine strains are important for viral prevention and control in the future. PMID:26711021

Genetic Characterization of H1N1 and H1N2 Influenza A Viruses Circulating in Ontario Pigs in 2012.

PubMed

Grgić, Helena; Costa, Marcio; Friendship, Robert M; Carman, Susy; Nagy, Éva; Poljak, Zvonimir

2015-01-01

The objective of this study was to characterize H1N1 and H1N2 influenza A virus isolates detected during outbreaks of respiratory disease in pig herds in Ontario (Canada) in 2012. Six influenza viruses were included in analysis using full genome sequencing based on the 454 platform. In five H1N1 isolates, all eight segments were genetically related to 2009 pandemic virus (A(H1N1)pdm09). One H1N2 isolate had hemagglutinin (HA), polymerase A (PA) and non-structural (NS) genes closely related to A(H1N1)pdm09, and neuraminidase (NA), matrix (M), polymerase B1 (PB1), polymerase B2 (PB2), and nucleoprotein (NP) genes originating from a triple-reassortant H3N2 virus (tr H3N2). The HA gene of five Ontario H1 isolates exhibited high identity of 99% with the human A(H1N1)pdm09 [A/Mexico/InDRE4487/09] from Mexico, while one Ontario H1N1 isolate had only 96.9% identity with this Mexican virus. Each of the five Ontario H1N1 viruses had between one and four amino acid (aa) changes within five antigenic sites, while one Ontario H1N2 virus had two aa changes within two antigenic sites. Such aa changes in antigenic sites could have an effect on antibody recognition and ultimately have implications for immunization practices. According to aa sequence analysis of the M2 protein, Ontario H1N1 and H1N2 viruses can be expected to offer resistance to adamantane derivatives, but not to neuraminidase inhibitors.

Impact of a potential glycosylation site at neuraminidase amino acid 264 of influenza A/H9N2 virus.

PubMed

Shao, Hongxia; Zhou, Xiaoxiang; Fan, Zhonglei; Wan, Zhimin; Qian, Kun; Perez, Daniel; Qin, Aijian; Ye, Jianqiang

2016-11-30

To determine the role of the potential glycosylation site NA264N, which has been shown to be prevalent in recent Chinese H9N2 isolates, four reverse genetic viruses, rgWS1-NA264N, rgWS1-NA264H, rgBJ-NA264H and rgBJ-NA264N, were rescued. Growth kinetics showed that viruses with NA264H grew faster than viruses with NA264N. Mouse studies revealed that rgBJ-NA264H replicated to a significantly higher titer than rgBJ-NA264N at 3dpi. Notably, in contact chickens, rgBJ-NA264H and rgWS1-NA264H shed significantly more virus than rgBJ-NA264N at 6dpi from the larynx and rgWS1-NA264N at 4dpi from the cloaca, respectively. The present study demonstrates that NA264N affects viral replication of H9N2. Copyright © 2016 Elsevier B.V. All rights reserved.

Pathogenesis and transmission of avian influenza A (H7N9) virus in ferrets and mice.

PubMed

Belser, Jessica A; Gustin, Kortney M; Pearce, Melissa B; Maines, Taronna R; Zeng, Hui; Pappas, Claudia; Sun, Xiangjie; Carney, Paul J; Villanueva, Julie M; Stevens, James; Katz, Jacqueline M; Tumpey, Terrence M

2013-09-26

On 29 March 2013, the Chinese Center for Disease Control and Prevention confirmed the first reported case of human infection with an avian influenza A(H7N9) virus. The recent human infections with H7N9 virus, totalling over 130 cases with 39 fatalities to date, have been characterized by severe pulmonary disease and acute respiratory distress syndrome (ARDS). This is concerning because H7 viruses have typically been associated with ocular disease in humans, rather than severe respiratory disease. This recent outbreak underscores the need to better understand the pathogenesis and transmission of these viruses in mammals. Here we assess the ability of A/Anhui/1/2013 and A/Shanghai/1/2013 (H7N9) viruses, isolated from fatal human cases, to cause disease in mice and ferrets and to transmit to naive animals. Both H7N9 viruses replicated to higher titre in human airway epithelial cells and in the respiratory tract of ferrets compared to a seasonal H3N2 virus. Moreover, the H7N9 viruses showed greater infectivity and lethality in mice compared to genetically related H7N9 and H9N2 viruses. The H7N9 viruses were readily transmitted to naive ferrets through direct contact but, unlike the seasonal H3N2 virus, did not transmit readily by respiratory droplets. The lack of efficient respiratory droplet transmission was corroborated by low receptor-binding specificity for human-like α2,6-linked sialosides. Our results indicate that H7N9 viruses have the capacity for efficient replication in mammals and human airway cells and highlight the need for continued public health surveillance of this emerging virus.

Continuing evolution of H9N2 avian influenza virus in South Korea

USDA-ARS?s Scientific Manuscript database

The H9N2 low pathogenic avian influenza (LPAI) has caused great economic losses in Korean poultry industry since the first outbreak in 1996. Although the hemagglutinin gene of early H9N2 viruses were closely related to Chinese Y439-like lineage virus, it evolved into a unique Korean lineage after ...

Pathogenicity of the Novel A/H7N9 Influenza Virus in Mice

PubMed Central

Mok, Chris Ka Pun; Lee, Horace Hok Yeung; Chan, Michael Chi Wai; Sia, Sin Fun; Lestra, Maxime; Nicholls, John Malcolm; Zhu, Huachen; Guan, Yi; Peiris, Joseph Malik Sriyal

2013-01-01

ABSTRACT A novel avian-origin influenza A/H7N9 virus infecting humans was first identified in March 2013 and, as of 30 May 2013, has caused 132 human infections leading to 33 deaths. Phylogenetic studies suggest that this virus is a reassortant, with the surface hemagglutinin (HA) and neuraminidase (NA) genes being derived from duck and wild-bird viruses, respectively, while the six “internal gene segments” were derived from poultry H9N2 viruses. Here we determine the pathogenicity of a human A/Shanghai/2/2013 (Sh2/H7N9) virus in healthy adult mice in comparison with that of A/chicken/Hong Kong/HH8/2010 (ck/H9N2) virus, highly pathogenic avian influenza (HPAI) A/Hong Kong/483/1997 (483/H5N1) virus, and a duck influenza A H7N9 virus of different genetic derivation, A/duck/Jiangxi/3286/2009 (dk/H7N9). Intranasal infection of mice with Sh2/H7N9 virus doses of 103, 104, and 105 PFU led to significant weight loss without fatality. This virus was more pathogenic than dk/H7N9 and ck/H9N2 virus, which has six internal gene segments that are genetically similar to Sh2/H7N9. Sh2/H7N9 replicated well in the nasal cavity and lung, but there was no evidence of virus dissemination beyond the respiratory tract. Mice infected with Sh2/H7N9 produced higher levels of proinflammatory cytokines in the lung and serum than did ck/H9N2 and dk/H7N9 but lower levels than 483/H5N1. Cytokine induction was positively correlated with virus load in the lung at early stages of infection. Our results suggest that Sh2/H7N9 virus is able to replicate and cause disease in mice without prior adaptation but is less pathogenic than 483/H5N1 virus. PMID:23820393

Genetic and antigenic evolution of H9N2 subtype avian influenza virus in domestic chickens in southwestern China, 2013–2016

PubMed Central

He, Xiao; Liu, Yue-Yue; Yao, Ke-Chang; Cao, San-Jie; Han, Xin-Feng; Huang, Yong

2017-01-01

H9N2 avian influenza virus (AIV) has caused significant losses in chicken flocks throughout china in recent years. There is a limited understanding of the genetic and antigenic characteristics of the H9N2 virus isolated in chickens in southwestern China. In this study a total of 12 field strains were isolated from tissue samples from diseased chickens between 2013 and 2016. Phylogenetic analysis of the Hemagglutinin (HA) and Neuraminidase (NA) nucleotide sequences from the 12 field isolates and other reference strains showed that most of the isolates in the past four years could be clustered into a major branch (HA-branch A and NA-branch I) in the Clade h9.4.2 lineages. These sequences are accompanied by nine and seven new amino acids mutations in the HA and NA proteins, respectively, when compared with those previous to 2013. In addition, four new isolates were grouped into a minor branch (HA-branch B) in the Clade h9.4.2 lineages and two potential N-glycosylation sites were observed due to amino acid mutations in the HA protein. Three antigenic groups (1–3), which had low antigenic relatedness with two commonly used vaccines in China, were identified among the 12 isolates by antigenMap analysis. Immunoprotection testing showed that those two vaccines could efficiently prevent the shedding of branch A viruses but not branch B viruses. In conclusion, these results indicate the genotype of branch B may become epidemic in the next few years and that a new vaccine should be developed for the prevention of H9N2 AIV. PMID:28158271

Low-pathogenic avian influenza virus A/turkey/Ontario/6213/1966 (H5N1) is the progenitor of highly pathogenic A/turkey/Ontario/7732/1966 (H5N9)

PubMed Central

Ping, Jihui; Selman, Mohammed; Tyler, Shaun; Forbes, Nicole; Keleta, Liya

2012-01-01

The first confirmed outbreak of highly pathogenic avian influenza (HPAI) virus infections in North America was caused by A/turkey/Ontario/7732/1966 (H5N9); however, the phylogeny of this virus is largely unknown. This study performed genomic sequence analysis of 11 avian influenza isolates from 1956 to 1979 for comparison with A/turkey/Ontario/7732/1966 (H5N9). Phylogenetic and genetic analyses included these viruses in combination with all known full-genome sequences of avian viruses isolated before 1981. It was shown that a low-pathogenic avian influenza virus, A/turkey/Ontario/6213/1966 (H5N1), that had been isolated 3 months previously, was the closest known genetic relative with six genome segments of common lineage encoding the polymerase subunits PB2, PB1 and PA, nucleoprotein (NP), haemagglutinin (HA) and non-structural (NS) proteins. The lineages of these genome segments included reassortment with other North American turkey viruses that were all rooted in North American wild waterfowl with the HA gene originating from the H5N2 serotype. The phylogenies demonstrated adaptation from North American wild birds to turkeys with the possible involvement of domestic waterfowl. The turkey isolate, A/turkey/Wisconsin/1968 (H5N9), was the second most closely related poultry isolate to A/turkey/Ontario/7732/1966 (H5N9), possessing five common lineage genome segments (PB2, PB1, PA, HA and neuraminidase). The A/turkey/Ontario/6213/1966 (H5N1) virus was more virulent than A/turkey/Wisconsin/68 (H5N9) for chicken embryos and mice, indicating a greater biological similarity to A/turkey/Ontario/7732/1966 (H5N9). Thus, A/turkey/Ontario/6213/1966 (H5N1) was identified as the closest known ancestral relative of HPAI A/turkey/Ontario/7732/1966 (H5N9), which will serve as a useful reference virus for characterizing the early genetic and biological properties associated with the emergence of pathogenic avian influenza strains. PMID:22592261

Reassortant H5N1 avian influenza viruses containing PA or NP gene from an H9N2 virus significantly increase the pathogenicity in mice.

PubMed

Hao, Xiaoli; Hu, Jiao; Wang, Jiongjiong; Xu, Jing; Cheng, Hao; Xu, Yunpeng; Li, Qunhui; He, Dongchang; Liu, Xiaowen; Wang, Xiaoquan; Gu, Min; Hu, Shunlin; Xu, Xiulong; Liu, Huimou; Chen, Sujuan; Peng, Daxin; Liu, Xiufan

2016-08-30

Reassortment between different influenza viruses is a crucial way to generate novel influenza viruses with unpredictable virulence and transmissibility, which may threaten the public health. As currently in China, avian influenza viruses (AIVs) of H9N2 and H5N1 subtypes are endemic in poultry in many areas, while they are prone to reassort with each other naturally. In order to evaluate the risk of the reassortment to public health, A/Goose/Jiangsu/k0403/2010 [GS/10(H5N1)] virus was used as a backbone to generate a series of reassortants, each contained a single internal gene derived from the predominant S genotype of the A/Chicken/Jiangsu/WJ57/2012 [WJ/57(H9N2)]. We next assessed the biological characteristics of these assortments, including pathogenicity, replication efficiency and polymerase activity. We found that the parental WJ/57(H9N2) and GS/10(H5N1) viruses displayed high genetic compatibility. Notably, the H5N1 reassortants containing the PA or NP gene from WJ/57(H9N2) virus significantly increased virulence and replication ability in mice, as well as markedly enhanced polymerase activity. Our results indicate that the endemicity of H9N2 and H5N1 in domestic poultry greatly increases the possibility of generating new viruses by reassortment that may pose a great threat to poultry industry and public health. Copyright © 2016 Elsevier B.V. All rights reserved.

Genetic Characterization of H1N1 and H1N2 Influenza A Viruses Circulating in Ontario Pigs in 2012

PubMed Central

Grgić, Helena; Costa, Marcio; Friendship, Robert M.; Carman, Susy; Nagy, Éva; Poljak, Zvonimir

2015-01-01

The objective of this study was to characterize H1N1 and H1N2 influenza A virus isolates detected during outbreaks of respiratory disease in pig herds in Ontario (Canada) in 2012. Six influenza viruses were included in analysis using full genome sequencing based on the 454 platform. In five H1N1 isolates, all eight segments were genetically related to 2009 pandemic virus (A(H1N1)pdm09). One H1N2 isolate had hemagglutinin (HA), polymerase A (PA) and non-structural (NS) genes closely related to A(H1N1)pdm09, and neuraminidase (NA), matrix (M), polymerase B1 (PB1), polymerase B2 (PB2), and nucleoprotein (NP) genes originating from a triple-reassortant H3N2 virus (tr H3N2). The HA gene of five Ontario H1 isolates exhibited high identity of 99% with the human A(H1N1)pdm09 [A/Mexico/InDRE4487/09] from Mexico, while one Ontario H1N1 isolate had only 96.9% identity with this Mexican virus. Each of the five Ontario H1N1 viruses had between one and four amino acid (aa) changes within five antigenic sites, while one Ontario H1N2 virus had two aa changes within two antigenic sites. Such aa changes in antigenic sites could have an effect on antibody recognition and ultimately have implications for immunization practices. According to aa sequence analysis of the M2 protein, Ontario H1N1 and H1N2 viruses can be expected to offer resistance to adamantane derivatives, but not to neuraminidase inhibitors. PMID:26030614

Isolation and genetic characterization of H5N2 influenza viruses from pigs in Korea.

PubMed

Lee, Jun Han; Pascua, Philippe Noriel Q; Song, Min-Suk; Baek, Yun Hee; Kim, Chul-Joong; Choi, Hwan-Woon; Sung, Moon-Hee; Webby, Richard J; Webster, Robert G; Poo, Haryoung; Choi, Young Ki

2009-05-01

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.

Avian Influenza A (H7N9) Virus

MedlinePlus

... Variant Pandemic Other Asian Lineage Avian Influenza A (H7N9) Virus Language: English (US) Español Recommend on Facebook ... Guidance Laboratorian Guidance H7N9 Images Additional Information Asian H7N9 Outbreak Characterization Asian H7N9 virus infections in poultry ...

Evolutionary dynamics of avian influenza A H7N9 virus across five waves in mainland China, 2013-2017.

PubMed

Xiang, Dan; Pu, Zhiqing; Luo, Tingting; Guo, Fucheng; Li, Xiaobing; Shen, Xuejuan; Irwin, David M; Murphy, Robert W; Liao, Ming; Shen, Yongyi

2018-05-25

Since its emergence in March 2013, novel avian influenza A H7N9 virus has triggered five epidemics of human infections in China. This raises concerns about the pandemic threat of this quickly evolving H7N9 subtype for humans. In this study, we evaluated all available genomes for H7N9 and H9N2 influenza A viruses. Our assessment discovered that H7N9 of the 1st wave had the lowest nucleotide diversity, which then experienced substantial and rapid population expansion from a small founder population. From the 2nd wave, their nucleotide diversity increased quickly, indicating that H7N9 viruses had acquired larger populations and mutations after their initial emergence in 2013. After the phylogeographic divergence in the 2nd wave, although the HA and NA genes from different regions differed, compared to previous epidemics, the evolving H7N9 viruses in the 5th wave lost most of their previous clades. The highly pathogenic avian influenza (HPAI) H7N9 viruses in the 5th wave clustered together, and clustered close to the low pathogenic avian influenza (LPAI) virus isolated from the Pearl River Delta in the 3rd and 4th waves. This result supports the origin of HPAI H7N9 viruses was in the Pearl River Delta. In the 5th wave, although both HPAI and LPAI H7N9 viruses were isolated from the Pearl River Delta, their HA and NA genes were phylogenetically distinct. Copyright © 2018. Published by Elsevier Ltd.

A point mutation in the polymerase protein PB2 allows a reassortant H9N2 influenza isolate of wild-bird origin to replicate in human cells.

USGS Publications Warehouse

Hussein, Islam T.M.; Ma, Eric J.; Meixell, Brandt W.; Hill, Nichola J.; Lindberg, Mark S.; Albrecht , Randy A.; Bahl, Justin; Runstadler, Jonathan A.

2016-01-01

H9N2 influenza A viruses are on the list of potentially pandemic subtypes. Therefore, it is important to understand how genomic reassortment and genetic polymorphisms affect phenotypes of H9N2 viruses circulating in the wild bird reservoir. A comparative genetic analysis of North American H9N2 isolates of wild bird origin identified a naturally occurring reassortant virus containing gene segments derived from both North American and Eurasian lineage ancestors. The PB2 segment of this virus encodes 10 amino acid changes that distinguish it from other H9 strains circulating in North America. G590S, one of the 10 amino acid substitutions observed, was present in ~ 12% of H9 viruses worldwide. This mutation combined with R591 has been reported as a marker of pathogenicity for human pandemic 2009 H1N1 viruses. Screening by polymerase reporter assay of all the natural polymorphisms at these two positions identified G590/K591 and S590/K591 as the most active, with the highest polymerase activity recorded for the SK polymorphism. Rescued viruses containing these two polymorphic combinations replicated more efficiently in MDCK cells and they were the only ones tested that were capable of establishing productive infection in NHBE cells. A global analysis of all PB2 sequences identified the K591 signature in six viral HA/NA subtypes isolated from several hosts in seven geographic locations. Interestingly, introducing the K591 mutation into the PB2 of a human-adapted H3N2 virus did not affect its polymerase activity. Our findings demonstrate that a single point mutation in the PB2 of a low pathogenic H9N2 isolate could have a significant effect on viral phenotype and increase its propensity to infect mammals. However, this effect is not universal, warranting caution in interpreting point mutations without considering protein sequence context.

A point mutation in the polymerase protein PB2 allows a reassortant H9N2 influenza isolate of wild-bird origin to replicate in human cells.

PubMed

Hussein, Islam T M; Ma, Eric J; Hill, Nichola J; Meixell, Brandt W; Lindberg, Mark; Albrecht, Randy A; Bahl, Justin; Runstadler, Jonathan A

2016-07-01

H9N2 influenza A viruses are on the list of potentially pandemic subtypes. Therefore, it is important to understand how genomic reassortment and genetic polymorphisms affect phenotypes of H9N2 viruses circulating in the wild bird reservoir. A comparative genetic analysis of North American H9N2 isolates of wild bird origin identified a naturally occurring reassortant virus containing gene segments derived from both North American and Eurasian lineage ancestors. The PB2 segment of this virus encodes 10 amino acid changes that distinguish it from other H9 strains circulating in North America. G590S, one of the 10 amino acid substitutions observed, was present in ~12% of H9 viruses worldwide. This mutation combined with R591 has been reported as a marker of pathogenicity for human pandemic 2009 H1N1 viruses. Screening by polymerase reporter assay of all the natural polymorphisms at these two positions identified G590/K591 and S590/K591 as the most active, with the highest polymerase activity recorded for the SK polymorphism. Rescued viruses containing these two polymorphic combinations replicated more efficiently in MDCK cells and they were the only ones tested that were capable of establishing productive infection in NHBE cells. A global analysis of all PB2 sequences identified the K591 signature in six viral HA/NA subtypes isolated from several hosts in seven geographic locations. Interestingly, introducing the K591 mutation into the PB2 of a human-adapted H3N2 virus did not affect its polymerase activity. Our findings demonstrate that a single point mutation in the PB2 of a low pathogenic H9N2 isolate could have a significant effect on viral phenotype and increase its propensity to infect mammals. However, this effect is not universal, warranting caution in interpreting point mutations without considering protein sequence context. Copyright © 2016 Elsevier B.V. All rights reserved.

Suspension culture process for H9N2 avian influenza virus (strain Re-2).

PubMed

Wang, Honglin; Guo, Suying; Li, Zhenguang; Xu, Xiaoqin; Shao, Zexiang; Song, Guicai

2017-10-01

H9N2 avian influenza virus has caused huge economic loss for the Chinese poultry industry since it was first identified. Vaccination is frequently used as a control method for the disease. Meanwhile suspension culture has become an important tool for the development of influenza vaccines. To optimize the suspension culture conditions for the avian influenza H9N2 virus (Re-2 strain) in Madin-Darby Canine Kidney (MDCK) cells, we studied the culture conditions for cell growth and proliferation parameters for H9N2 virus replication. MDCK cells were successfully cultured in suspension, from a small scale to industrial levels of production, with passage time and initial cell density being optimized. The influence of pH on the culture process in the reactor has been discussed and the process parameters for industrial production were explored via amplification of the 650L reactor. Subsequently, we cultivated cells at high cell density and harvested high amounts of virus, reaching 10log2 (1:1024). Furthermore an animal experiment was conducted to detect antibody. Compared to the chicken embryo virus vaccine, virus cultured from MDCK suspension cells can produce a higher amount of antibodies. The suspension culture process is simple and cost efficient, thus providing a solid foundation for the realization of large-scale avian influenza vaccine production.

Heterologous Humoral Response against H5N1, H7N3, and H9N2 Avian Influenza Viruses after Seasonal Vaccination in a European Elderly Population

PubMed Central

Sanz, Ivan; Rojo, Silvia; Tamames, Sonia; Eiros, José María; Ortiz de Lejarazu, Raúl

2017-01-01

Avian influenza viruses are currently one of the main threats to human health in the world. Although there are some screening reports of antibodies against these viruses in humans from Western countries, most of these types of studies are conducted in poultry and market workers of Asian populations. The presence of antibodies against avian influenza viruses was evaluated in an elderly European population. An experimental study was conducted, including pre- and post-vaccine serum samples obtained from 174 elderly people vaccinated with seasonal influenza vaccines of 2006–2007, 2008–2009, 2009–2010, and 2010–2011 Northern Hemisphere vaccine campaigns. The presence of antibodies against A/H5N1, A/H7N3, and A/H9N2 avian influenza viruses were tested by using haemaglutination inhibition assays. Globally, heterotypic antibodies were found before vaccination in 2.9% of individuals against A/H5N1, 1.2% against A/H7N3, and 25.9% against A/H9N2. These pre-vaccination antibodies were present at titers ≥1/40 in 1.1% of individuals against A/H5N1, in 1.1% against H7N3, and in 0.6% against the A/H9N2 subtype. One 76 year-old male showed pre-vaccine antibodies (Abs) against those three avian influenza viruses, and another three individuals presented Abs against two different viruses. Seasonal influenza vaccination induced a significant number of heterotypic seroconversions against A/H5N1 (14.4%) and A/H9N2 (10.9%) viruses, but only one seroconversion was observed against the A/H7N3 subtype. After vaccination, four individuals showed Abs titers ≥1/40 against those three avian viruses, and 55 individuals against both A/H5N1 and A/H9N2. Seasonal vaccination is able to induce some weak heterotypic responses to viruses of avian origin in elderly individuals with no previous exposure to them. However, this response did not accomplish the European Medicament Agency criteria for influenza vaccine efficacy. The results of this study show that seasonal vaccines induce a broad

Screening host proteins required for bacterial adherence after H9N2 virus infection.

PubMed

Ma, Li-Li; Sun, Zhen-Hong; Xu, Yu-Lin; Wang, Shu-Juan; Wang, Hui-Ning; Zhang, Hao; Hu, Li-Ping; Sun, Xiao-Mei; Zhu, Lin; Shang, Hong-Qi; Zhu, Rui-Liang; Wei, Kai

2018-01-01

H9N2 subtype low pathogenic avian influenza virus (LPAIV) is distributed worldwide and causes great economic losses in the poultry industry, especially when complicated with other bacterial infections. Tissue damages caused by virus infection provide an opportunity for bacteria invasion, but this mechanism is not sufficient for low pathogenic strains. Moreover, although H9N2 virus infection was demonstrated to promote bacterial infection in several studies, its mechanism remained unclear. In this study, infection experiments in vivo and in vitro demonstrated that the adhesion of Escherichia coli (E. coli) to host cells significantly increased after H9N2 virus infection, and this increase was not caused by pathological damages. Subsequently, we constructed a late chicken embryo infection model and used proteomics techniques to analyze the expression of proteins associated with bacterial adhesion after H9N2 virus infection. A total of 279 significantly differential expressed proteins were detected through isobaric tags for relative and absolute quantitation (iTRAQ) coupled with nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS/MS) analysis. The results of Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis showed that differentially expressed proteins were enriched in host innate immunity; cell proliferation, differentiation, and apoptosis; and pathogenicity-related signaling pathways. Finally, we screened out several proteins, such as TGF-β1, integrins, cortactin, E-cadherin, vinculin, and fibromodulin, which were probably associated with bacterial adhesion. The study analyzed the mechanism of secondary bacterial infection induced by H9N2 virus infection from a novel perspective, which provided theoretical and data support for investigating the synergistic infection mechanism between the H9N2 virus and bacteria. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of a reassortant H11N9 subtype avian influenza virus isolated from bean goose along the East Asian-Australian flyway.

PubMed

Yao, Yanfeng; Shao, Zhiyong; He, Bin; Yang, Wenhai; Chen, Jianjun; Zhang, Tao; Chen, Xiabing; Chen, Jie

2017-02-01

During the surveillance of avian influenza viruses in the Dongxi Lake wetland of Hubei in 2015-2016, an H11N9 avian influenza virus was isolated from a bean goose (Anser fabalis). Phylogenetic analysis showed that the HA gene of this isolate belongs to the North American lineage; however, the NA and the internal genes of the isolate were generated from the Eurasian lineage. This strain had reduced pathogenicity in mice and was capable of replication in the mouse lung without prior adaptation. This is the first report detecting H11N9 subtype influenza virus from migratory birds in central China. These findings highlight the transmission of avian influenza virus along the East Asian-Australian flyway and the need for continuing surveillance in central China.

A new reassortment of influenza A (H7N9) virus causing human infection in Beijing, 2014.

PubMed

Bi, Yuhai; Liu, Jingyuan; Xiong, Haofeng; Zhang, Yue; Liu, Di; Liu, Yingxia; Gao, George F; Wang, Beibei

2016-05-27

A 73-year-old man was confirmed to have an influenza A (H7N9) virus infection, and the causative agent A/Beijing/02/2014(H7N9) virus was isolated. Genetic and phylogenetic analyses revealed that the virus belonged to a novel genotype, which probably emerged and further reassorted with other H9 or H7 viruses in poultry before transmitting to humans. This virus caused a severe infection with high levels of cytokines and neutralizing antibodies. Eventually, the patient was cured after serially combined treatments. Taken together, our findings indicated that this novel genotype of the human H7N9 virus did not evolve directly from the first Beijing isolate A/Beijing/01/2013(H7N9), suggesting that the H7N9 virus has not obtained the ability for human-to-human transmissibility and the virus only evolves in poultry and then infects human by direct contact. Hence, the major measures to prevent human H7N9 virus infection are still to control and standardize the live poultry trade. Early antiviral treatment with combination therapies, including mechanical ventilation, nutrition support and symptomatic treatment, are effective for H7N9 infection.

H7N9 Influenza Virus Is More Virulent in Ferrets than 2009 Pandemic H1N1 Influenza Virus.

PubMed

Yum, Jung; Ku, Keun Bon; Kim, Hyun Soo; Seo, Sang Heui

2015-12-01

The novel H7N9 influenza virus has been infecting humans in China since February 2013 and with a mortality rate of about 40%. This study compared the pathogenicity of the H7N9 and 2009 pandemic H1N1 influenza viruses in a ferret model, which shows similar symptoms to those of humans infected with influenza viruses. The H7N9 influenza virus caused a more severe disease than did the 2009 pandemic H1N1 influenza virus. All of the ferrets infected with the H7N9 influenza virus had died by 6 days after infection, while none of those infected with the 2009 pandemic H1N1 influenza virus died. Ferrets infected with the H7N9 influenza virus had higher viral titers in their lungs than did those infected with the 2009 pandemic H1N1 influenza virus. Histological findings indicated that hemorrhagic pneumonia was caused by infection with the H7N9 influenza virus, but not with the 2009 pandemic H1N1 influenza virus. In addition, the lung tissues of ferrets infected with the H7N9 influenza virus contained higher levels of chemokines than did those of ferrets infected with the 2009 pandemic H1N1 influenza virus. This study suggests that close monitoring is needed to prevent human infection by the lethal H7N9 influenza virus.

A Single Mutation at Position 190 in Hemagglutinin Enhances Binding Affinity for Human Type Sialic Acid Receptor and Replication of H9N2 Avian Influenza Virus in Mice

PubMed Central

Teng, Qiaoyang; Xu, Dawei; Shen, Weixia; Liu, Qinfang; Rong, Guangyu; Li, Xuesong; Yan, Liping; Yang, Jianmei; Chen, Hongjun; Yu, Hai

2016-01-01

ABSTRACT H9N2 avian influenza virus (AIV) has an extended host range, but the molecular basis underlying H9N2 AIV transmission to mammals remains unclear. We isolated more than 900 H9N2 AIVs in our 3-year surveillance in live bird markets in China from 2009 to 2012. Thirty-seven representative isolates were selected for further detailed characterization. These isolates were categorized into 8 genotypes (B64 to B71) and formed a distinct antigenic subgroup. Three isolates belonging to genotype B69, which is a predominant genotype circulating in China, replicated efficiently in mice, while the viruses tested in parallel in other genotypes replicated poorly, although they, like the three B69 isolates, have a leucine at position 226 in the hemagglutinin (HA) receptor binding site, which is critical for binding human type sialic acid receptors. Further molecular and single mutation analysis revealed that a valine (V) residue at position 190 in HA is responsible for efficient replication of these H9N2 viruses in mice. The 190V in HA does not affect virus receptor binding specificity but enhances binding affinity to human cells and lung tissues from mouse and humans. All these data indicate that the 190V in HA is one of the important determinants for H9N2 AIVs to cross the species barrier to infect mammals despite multiple genes conferring adaptation and replication of H9N2 viruses in mammals. Our findings provide novel insights on understanding host range expansion of H9N2 AIVs. IMPORTANCE Influenza virus hemagglutinin (HA) is responsible for binding to host cell receptors and therefore influences the viral host range and pathogenicity in different species. We showed that the H9N2 avian influenza viruses harboring 190V in the HA exhibit enhanced virus replication in mice. Further studies demonstrate that 190V in the HA does not change virus receptor binding specificity but enhances virus binding affinity of the H9N2 virus to human cells and attachment to lung tissues

A Single Mutation at Position 190 in Hemagglutinin Enhances Binding Affinity for Human Type Sialic Acid Receptor and Replication of H9N2 Avian Influenza Virus in Mice.

PubMed

Teng, Qiaoyang; Xu, Dawei; Shen, Weixia; Liu, Qinfang; Rong, Guangyu; Li, Xuesong; Yan, Liping; Yang, Jianmei; Chen, Hongjun; Yu, Hai; Ma, Wenjun; Li, Zejun

2016-11-01

H9N2 avian influenza virus (AIV) has an extended host range, but the molecular basis underlying H9N2 AIV transmission to mammals remains unclear. We isolated more than 900 H9N2 AIVs in our 3-year surveillance in live bird markets in China from 2009 to 2012. Thirty-seven representative isolates were selected for further detailed characterization. These isolates were categorized into 8 genotypes (B64 to B71) and formed a distinct antigenic subgroup. Three isolates belonging to genotype B69, which is a predominant genotype circulating in China, replicated efficiently in mice, while the viruses tested in parallel in other genotypes replicated poorly, although they, like the three B69 isolates, have a leucine at position 226 in the hemagglutinin (HA) receptor binding site, which is critical for binding human type sialic acid receptors. Further molecular and single mutation analysis revealed that a valine (V) residue at position 190 in HA is responsible for efficient replication of these H9N2 viruses in mice. The 190V in HA does not affect virus receptor binding specificity but enhances binding affinity to human cells and lung tissues from mouse and humans. All these data indicate that the 190V in HA is one of the important determinants for H9N2 AIVs to cross the species barrier to infect mammals despite multiple genes conferring adaptation and replication of H9N2 viruses in mammals. Our findings provide novel insights on understanding host range expansion of H9N2 AIVs. Influenza virus hemagglutinin (HA) is responsible for binding to host cell receptors and therefore influences the viral host range and pathogenicity in different species. We showed that the H9N2 avian influenza viruses harboring 190V in the HA exhibit enhanced virus replication in mice. Further studies demonstrate that 190V in the HA does not change virus receptor binding specificity but enhances virus binding affinity of the H9N2 virus to human cells and attachment to lung tissues from humans and mouse

Serological and virological surveillance of avian influenza A virus H9N2 subtype in humans and poultry in Shanghai, China, between 2008 and 2010.

PubMed

Wang, Q; Ju, L; Liu, P; Zhou, J; Lv, X; Li, L; Shen, H; Su, H; Jiang, L; Jiang, Q

2015-03-01

We report the serological evidence of low-pathogenic avian influenza (LPAI) H9N2 infection in an occupational poultry-exposed population and a general population. A serological survey of an occupational poultry-exposed population and a general population was conducted using a haemagglutinin-inhibiting (HI) assay in Shanghai, China, from January 2008 to December 2010. Evidence of higher anti-H9 antibodies was found in serum samples collected from poultry workers. During this period, 239 H9N2 avian influenza viruses (AIVs) were isolated from 9297 tracheal and cloacal paired specimens collected from the poultry in live poultry markets. In addition, a total of 733 influenza viruses were isolated from 1569 nasal and throat swabs collected from patients with influenza-like symptoms in a sentinel hospital, which include H3N2, H1N1, pandemic H1N1 and B, but no H9N2 virus was detected. These findings highlight the need for long-term surveillance of avian influenza viruses in occupational poultry-exposed workers. © 2014 The Authors. Zoonoses and Public Health Published by Blackwell Verlag GmbH.

Poultry farms as a source of avian influenza A (H7N9) virus reassortment and human infection

PubMed Central

Wu, Donglin; Zou, Shumei; Bai, Tian; Li, Jing; Zhao, Xiang; Yang, Lei; Liu, Hongmin; Li, Xiaodan; Yang, Xianda; Xin, Li; Xu, Shuang; Zou, Xiaohui; Li, Xiyan; Wang, Ao; Guo, Junfeng; Sun, Bingxin; Huang, Weijuan; Zhang, Ye; Li, Xiang; Gao, Rongbao; Shen, Bo; Chen, Tao; Dong, Jie; Wei, Hejiang; Wang, Shiwen; Li, Qun; Li, Dexin; Wu, Guizhen; Feng, Zijian; Gao, George F.; Wang, Yu; Wang, Dayan; Fan, Ming; Shu, Yuelong

2015-01-01

Live poultry markets are a source of human infection with avian influenza A (H7N9) virus. On February 21, 2014, a poultry farmer infected with H7N9 virus was identified in Jilin, China, and H7N9 and H9N2 viruses were isolated from the patient's farm. Reassortment between these subtype viruses generated five genotypes, one of which caused the human infection. The date of H7N9 virus introduction to the farm is estimated to be between August 21, 2013 (95% confidence interval [CI] June 6, 2013-October 6, 2013) and September 25, 2013 (95% CI May 28, 2013-January 4, 2014), suggesting that the most likely source of virus introduction was the first batch of poultry purchased in August 2013. The reassortment event that led to the human virus may have occurred between January 2, 2014 (95% CI November 8, 2013-February 12, 2014) and February 12, 2014 (95% CI January 19, 2014-February 18, 2014). Our findings demonstrate that poultry farms could be a source of reassortment between H7N9 virus and H9N2 virus as well as human infection, which emphasizes the importance to public health of active avian influenza surveillance at poultry farms. PMID:25591105

High genetic compatibility and increased pathogenicity of reassortants derived from avian H9N2 and pandemic H1N1/2009 influenza viruses

PubMed Central

Sun, Yipeng; Qin, Kun; Wang, Jingjing; Pu, Juan; Tang, Qingdong; Hu, Yanxin; Bi, Yuhai; Zhao, Xueli; Yang, Hanchun; Shu, Yuelong; Liu, Jinhua

2011-01-01

H9N2 influenza viruses have been circulating worldwide in multiple avian species and repeatedly infecting mammals, including pigs and humans, posing a significant threat to public health. The coexistence of H9N2 and pandemic influenza H1N1/2009 viruses in pigs and humans provides an opportunity for these viruses to reassort. To evaluate the potential public risk of the reassortant viruses derived from these viruses, we used reverse genetics to generate 127 H9 reassortants derived from an avian H9N2 and a pandemic H1N1 virus, and evaluated their compatibility, replication ability, and virulence in mice. These hybrid viruses showed high genetic compatibility and more than half replicated to a high titer in vitro. In vivo studies of 73 of 127 reassortants revealed that all viruses were able to infect mice without prior adaptation and 8 reassortants exhibited higher pathogenicity than both parental viruses. All reassortants with higher virulence than parental viruses contained the PA gene from the 2009 pandemic virus, revealing the important role of the PA gene from the H1N1/2009 virus in generating a reassortant virus with high public health risk. Analyses of the polymerase activity of the 16 ribonucleoprotein combinations in vitro suggested that the PA of H1N1/2009 origin also enhanced polymerase activity. Our results indicate that some avian H9-pandemic reassortants could emerge with a potentially higher threat for humans and also highlight the importance of monitoring the H9-pandemic reassortant viruses that may arise, especially those that possess the PA gene of H1N1/2009 origin. PMID:21368167

Poultry vaccination directed evolution of H9N2 low pathogenicity avian influenza viruses in Korea.

PubMed

Lee, Dong-Hun; Fusaro, Alice; Song, Chang-Seon; Suarez, David L; Swayne, David E

2016-01-15

Significant economic losses in the poultry industries have resulted from H9N2 low pathogenic avian influenza virus infections across North Africa, the Middle East and Asia. The present study investigated the evolutionary dynamics of H9N2 viruses circulating in Korea from 1996 to 2012. Our analysis of viral population dynamics revealed an increase in genetic diversity between the years 2003 and 2007, corresponding to the spread and diversification of H9N2 viruses into multiple genetic groups (named A and B), followed by a sudden decrease in 2007, which was associated with implementation of vaccination using a Clade A virus. Implementation of the H9N2 vaccination program in Korea has dramatically reduced the diversity of H9N2 virus, and only one sub-lineage of clade B has survived, expanded, and currently circulates in Korea. In addition, the antigenic drift of this new genetic group away from the current vaccine strain suggests the need to update the vaccine seed strain. Published by Elsevier Inc.

Evaluation of homologous inactivated influenza vaccine for protection of chickens against the H7N9 virus isolated in Anhui, China during 2013

USDA-ARS?s Scientific Manuscript database

The recent outbreak of avian influenza (AI) H7N9 in humans in China in 2013 has resulted in approximately 30 % mortality. The genetic composition of these H7N9 viruses appears to be solely of avian origin. Although few isolations of these viruses have been demonstrated on poultry farms, the correlat...

An H5N1-based matrix protein 2 ectodomain tetrameric peptide vaccine provides cross-protection against lethal infection with H7N9 influenza virus.

PubMed

Leung, Ho-Chuen; Chan, Chris Chung-Sing; Poon, Vincent Kwok-Man; Zhao, Han-Jun; Cheung, Chung-Yan; Ng, Fai; Huang, Jian-Dong; Zheng, Bo-Jian

2015-04-01

In March 2013, a patient infected with a novel avian influenza A H7N9 virus was reported in China. Since then, there have been 458 confirmed infection cases and 177 deaths. The virus contains several human-adapted markers, indicating that H7N9 has pandemic potential. The outbreak of this new influenza virus highlighted the need for the development of universal influenza vaccines. Previously, we demonstrated that a tetrameric peptide vaccine based on the matrix protein 2 ectodomain (M2e) of the H5N1 virus (H5N1-M2e) could protect mice from lethal infection with different clades of H5N1 and 2009 pandemic H1N1 influenza viruses. In this study, we investigated the cross-protection of H5N1-M2e against lethal infection with the new H7N9 virus. Although five amino acid differences existed at positions 13, 14, 18, 20, and 21 between M2e of H5N1 and H7N9, H5N1-M2e vaccination with either Freund's adjuvant or the Sigma adjuvant system (SAS) induced a high level of anti-M2e antibody, which cross-reacted with H7N9-M2e peptide. A mouse-adapted H7N9 strain, A/Anhui/01/2013m, was used for lethal challenge in animal experiments. H5N1-M2e vaccination provided potent cross-protection against lethal challenge of the H7N9 virus. Reduced viral replication and histopathological damage of mouse lungs were also observed in the vaccinated mice. Our results suggest that the tetrameric H5N1-M2e peptide vaccine could protect against different subtypes of influenza virus infections. Therefore, this vaccine may be an ideal candidate for developing a universal vaccine to prevent the reemergence of avian influenza A H7N9 virus and the emergence of potential novel reassortants of influenza virus.