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Sample records for influenza virus subtypes

  1. Influenza Type A Viruses and Subtypes

    MedlinePlus

    ... virus infection of humans, such as with Asian-origin highly pathogenic avian influenza A (H5N1) viruses currently circulating among poultry in Asia and the Middle East have been reported in 16 countries, often resulting in severe pneumonia with approximately 60% ...

  2. Oligonucleotide microchip for subtyping of influenza A virus

    PubMed Central

    Fesenko, Eugeny E.; Kireyev, Dmitry E.; Gryadunov, Dmitry A.; Mikhailovich, Vladimir M.; Grebennikova, Tatyana V.; L’vov, Dmitry K.; Zasedatelev, Alexander S.

    2007-01-01

    Background  Influenza A viruses are classified into subtypes depending on the antigenic properties of their two outer glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Sixteen subtypes of HA and nine of NA are known. Lately, the circulation of some subtypes (H7N7, H5N1) has been closely watched because of the epidemiological threat they present. Objectives  This study assesses the potential of using gel‐based microchip technology for fast and sensitive molecular subtyping of the influenza A virus. Methods  The method employs a microchip of 3D gel‐based elements containing immobilized probes. Segments of the HA and NA genes are amplified using multiplex RT‐PCR and then hybridized with the microchip. Results  The developed microchip was validated using a panel of 21 known reference strains of influenza virus. Selected strains represented different HA and NA subtypes derived from avian, swine and human hosts. The whole procedure takes 10 hours and enables one to identify 15 subtypes of HA and two subtypes of NA. Forty‐one clinical samples isolated during the poultry fall in Novosibirsk (Russia, 2005) were successfully identified using the proposed technique. The sensitivity and specificity of the method were 76% and 100%, respectively, compared with the ‘gold standard’ techniques (virus isolation with following characterization by immunoassay). Conclusions  We conclude that the method of subtyping using gel‐based microchips is a promising approach for fast detection and identification of influenza A, which may greatly improve its monitoring. PMID:19453417

  3. Oligonucleotide microarray for subtyping of influenza A viruses

    NASA Astrophysics Data System (ADS)

    Klotchenko, S. A.; Vasin, A. V.; Sandybaev, N. T.; Plotnikova, M. A.; Chervyakova, O. V.; Smirnova, E. A.; Kushnareva, E. V.; Strochkov, V. M.; Taylakova, E. T.; Egorov, V. V.; Koshemetov, J. K.; Kiselev, O. I.; Sansyzbay, A. R.

    2012-02-01

    Influenza is one of the most widespread respiratory viral diseases, infecting humans, horses, pigs, poultry and some other animal populations. Influenza A viruses (IAV) are classified into subtypes on the basis of the surface hemagglutinin (H1 to H16) and neuraminidase (N1 to N9) glycoproteins. The correct determination of IAV subtype is necessary for clinical and epidemiological studies. In this article we propose an oligonucleotide microarray for subtyping of IAV using universal one-step multisegment RT-PCR fluorescent labeling of viral gene segments. It showed to be an advanced approach for fast detection and identification of IAV.

  4. Hemagglutination-inhibition assay for influenza virus subtype identification and the detection and quantitation of serum antibodies to influenza virus.

    PubMed

    Pedersen, Janice C

    2014-01-01

    Hemagglutination-inhibition (HI) assay is a classical laboratory procedure for the classification or subtyping of hemagglutinating viruses. For influenza virus, HI assay is used to identify the hemagglutinin (HA) subtype of an unknown isolate or the HA subtype specificity of antibodies to influenza virus. Since the HI assay is quantitative it is frequently applied to evaluate the antigenic relationships between different influenza virus isolates of the same subtype. The basis of the HI test is inhibition of hemagglutination with subtype-specific antibodies. The HI assay is a relatively inexpensive procedure utilizing standard laboratory equipment, is less technical than molecular tests, and is easily completed within several hours. However when working with uncharacterized viruses or antibody subtypes the library of reference reagents required for identifying antigenically distinct influenza viruses and or antibody specificities from multiple lineages of a single hemagglutinin subtype requires extensive laboratory support for the production and optimization of reagents. PMID:24899416

  5. A Complete Molecular Diagnostic Procedure for Applications in Surveillance and Subtyping of Avian Influenza Virus

    PubMed Central

    Tseng, Chun-Hsien; Tsai, Hsiang-Jung; Chang, Chung-Ming

    2014-01-01

    Introduction. The following complete molecular diagnostic procedure we developed, based on real-time quantitative PCR and traditional PCR, is effective for avian influenza surveillance, virus subtyping, and viral genome sequencing. Method. This study provides a specific and sensitive step-by-step procedure for efficient avian influenza identification of 16 hemagglutinin and 9 neuraminidase avian influenza subtypes. Result and Conclusion. This diagnostic procedure may prove exceedingly useful for virological and ecological advancements in global avian influenza research. PMID:25057497

  6. Type- and subtype-specific detection of influenza viruses in clinical specimens by rapid culture assay.

    PubMed

    Ziegler, T; Hall, H; Sánchez-Fauquier, A; Gamble, W C; Cox, N J

    1995-02-01

    A rapid culture assay which allows for the simultaneous typing and subtyping of currently circulating influenza A(H1N1), A(H3N2), and B viruses in clinical specimens was developed. Pools of monoclonal antibodies (MAbs) against influenza A and B viruses and MAbs HA1-71 and HA2-76, obtained by immunizing mice with the denatured hemagglutinin subfragments HA1 and HA2 of influenza virus A/Victoria/3/75, were used for immunoperoxidase staining of antigens in infected MDCK cells. MAb HA1-71 reacted exclusively with influenza A viruses of the H3 subtype, while MAb HA2-76 reacted with subtypes H1, H3, H4, H6, H8, H9, H10, H11, and H12, as determined with 78 human, 4 swine, and 10 avian influenza virus reference strains subtyped by the hemagglutination inhibition test. To determine if the technique can be used as a rapid diagnostic test, 263 known influenza virus-positive frozen nasal or throat swabs were inoculated into MDCK cells. After an overnight incubation, the cells were fixed and viral antigens were detected by immunoperoxidase staining. Influenza A viruses of the H1 and H3 subtypes were detected in 31 and 113 specimens, respectively. The subtypes of 10 influenza A virus-positive specimens could not be determined because they contained too little virus. Influenza B viruses were detected in 84 specimens, and 25 specimens were negative. We conclude that this assay is a rapid, convenient, non-labor-intensive, and relatively inexpensive test for detecting, typing, and subtyping influenza viruses in clinical specimens. PMID:7714186

  7. Integrating Decision Tree and Hidden Markov Model (HMM) for Subtype Prediction of Human Influenza A Virus

    NASA Astrophysics Data System (ADS)

    Attaluri, Pavan K.; Chen, Zhengxin; Weerakoon, Aruna M.; Lu, Guoqing

    Multiple criteria decision making (MCDM) has significant impact in bioinformatics. In the research reported here, we explore the integration of decision tree (DT) and Hidden Markov Model (HMM) for subtype prediction of human influenza A virus. Infection with influenza viruses continues to be an important public health problem. Viral strains of subtype H3N2 and H1N1 circulates in humans at least twice annually. The subtype detection depends mainly on the antigenic assay, which is time-consuming and not fully accurate. We have developed a Web system for accurate subtype detection of human influenza virus sequences. The preliminary experiment showed that this system is easy-to-use and powerful in identifying human influenza subtypes. Our next step is to examine the informative positions at the protein level and extend its current functionality to detect more subtypes. The web functions can be accessed at http://glee.ist.unomaha.edu/.

  8. Comparative susceptibility of avian species to low pathogenic avian influenza viruses of the H13 subtype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemag...

  9. Antigenic Characterization of Recombinant Hemagglutinin Proteins Derived from Different Avian Influenza Virus Subtypes

    PubMed Central

    Mueller, Matthias; Renzullo, Sandra; Brooks, Roxann; Ruggli, Nicolas; Hofmann, Martin A.

    2010-01-01

    Since the advent of highly pathogenic variants of avian influenza virus (HPAIV), the main focus of avian influenza research has been the characterization and detection of HPAIV hemagglutinin (HA) from H5 and H7 subtypes. However, due to the high mutation and reassortation rate of influenza viruses, in theory any influenza strain may acquire increased pathogenicity irrespective of its subtype. A comprehensive antigenic characterization of influenza viruses encompassing all 16 HA and 9 neuraminidase subtypes will provide information useful for the design of differential diagnostic tools, and possibly, vaccines. We have expressed recombinant HA proteins from 3 different influenza virus HA subtypes in the baculovirus system. These proteins were used to generate polyclonal rabbit antisera, which were subsequently employed in epitope scanning analysis using peptide libraries spanning the entire HA. Here, we report the identification and characterization of linear, HA subtype-specific as well as inter subtype-conserved epitopes along the HA proteins. Selected subtype-specific epitopes were shown to be suitable for the differentiation of anti-HA antibodies in an ELISA. PMID:20140098

  10. The pathogenicity of H7 subtype avian influenza viruses in chickens, turkeys and ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) viruses infect numerous avian species, and low pathogenicity (LP) AI viruses of the H7 subtype are typically reported to produce mild or subclinical infections in both wild aquatic birds and domestic poultry. However relatively little work has been done to compare LPAI viruses ...

  11. Universal antibodies against the highly conserved influenza fusion peptide cross-neutralize several subtypes of influenza A virus

    SciTech Connect

    Hashem, Anwar M.; Van Domselaar, Gary; Li, Changgui; Wang, Junzhi; She, Yi-Min; Cyr, Terry D.; Sui, Jianhua; He, Runtao; Marasco, Wayne A.; Li, Xuguang

    2010-12-10

    Research highlights: {yields} The fusion peptide is the only universally conserved epitope in all influenza viral hemagglutinins. {yields} Anti-fusion peptide antibodies are universal antibodies that cross-react with all influenza HA subtypes. {yields} The universal antibodies cross-neutralize different influenza A subtypes. {yields} The universal antibodies inhibit the fusion process between the viruses and the target cells. -- Abstract: The fusion peptide of influenza viral hemagglutinin plays a critical role in virus entry by facilitating membrane fusion between the virus and target cells. As the fusion peptide is the only universally conserved epitope in all influenza A and B viruses, it could be an attractive target for vaccine-induced immune responses. We previously reported that antibodies targeting the first 14 amino acids of the N-terminus of the fusion peptide could bind to virtually all influenza virus strains and quantify hemagglutinins in vaccines produced in embryonated eggs. Here we demonstrate that these universal antibodies bind to the viral hemagglutinins in native conformation presented in infected mammalian cell cultures and neutralize multiple subtypes of virus by inhibiting the pH-dependant fusion of viral and cellular membranes. These results suggest that this unique, highly-conserved linear sequence in viral hemagglutinin is exposed sufficiently to be attacked by the antibodies during the course of infection and merits further investigation because of potential importance in the protection against diverse strains of influenza viruses.

  12. Seroepidemiological Evidence of Subtype H3N8 Influenza Virus Infection among Pet Dogs in China

    PubMed Central

    Zhou, Pei; Huang, San; Zeng, Weijie; Zhang, Xin; Wang, Lifang; Fu, Xinliang; Li, Shoujun

    2016-01-01

    The H3N8 virus and the H3N2 virus are the main subtypes of canine influenza virus (CIV). H3N8 CIV mainly circulates in America, and H3N2 CIV mainly circulates in Asia. However, there was an outbreak of the Asian H3N2 virus in the United States (US) in 2015. Thus, it is important to evaluate the presence of subtype H3N8 virus in dogs in China. From May 2015 to November 2015, 600 sera from pet dogs were collected from Guangzhou, Shanghai, Beijing and Shenzhen for hemagglutination inhibition (HI) assays and microneutralization (MN) assays. Fifty-two (8.66%) of the 600 sera were positive for the subtype H3N2 virus, which matched the previous reports. Five (0.83%) of 600 sera were positive for the subtype H3N8 virus (H3N8 EIV or H3N8 AIV or H3N8 CIV), which is the first report of subtype H3N8 virus infection among dogs in China and remind us to play more attention to this subtype virus. Therefore, further serological and virological surveillance of influenza virus infection among dogs in China is imperative. PMID:27414031

  13. [Simultaneous detection of respiratory viruses and influenza A virus subtypes using multiplex PCR].

    PubMed

    Ciçek, Candan; Bayram, Nuri; Anıl, Murat; Gülen, Figen; Pullukçu, Hüsnü; Saz, Eylem Ulaş; Telli, Canan; Cok, Gürsel

    2014-10-01

    This study was conducted to investigate the respiratory viruses and subtyping of influenza A virus when positive by multiplex PCR in patients with flu-like symptoms, after the pandemic caused by influenza A (H1N1)pdm09. Nasopharyngeal swab samples collected from 700 patients (313 female, 387 male; age range: 24 days-94 yrs, median age: 1 yr) between December 2010 - January 2013 with flu-like symptoms including fever, headache, sore throat, rhinitis, cough, myalgia as defined by the World Health Organization were included in the study. Nucleic acid extractions (Viral DNA/RNA Extraction Kit, iNtRON, South Korea) and cDNA synthesis (RevertAid First Strand cDNA Synthesis Kits, Fermentas, USA) were performed according to the manufacturer's protocol. Multiplex amplification of nucleic acids was performed using DPO (dual priming oligonucleotide) primers and RV5 ACE Screening Kit (Seegene, South Korea) in terms of the presence of influenza A (INF-A) virus, influenza B (INF-B) virus, respiratory syncytial virus (RSV), and the other respiratory viruses. PCR products were detected by automated polyacrylamide gel electrophoresis using Screen Tape multiple detection system. Specimens which were positive for viral nucleic acids have been further studied by using specific DPO primers, FluA ACE Subtyping and RV15 Screening (Seegene, South Korea) kits. Four INF-A virus subtypes [human H1 (hH1), human H3 (hH3), swine H1 (sH1), avian H5 (aH5)] and 11 other respiratory viruses [Adenovirus, parainfluenza virus (PIV) types 1-4, human bocavirus (HBoV), human metapneumovirus (HMPV), rhinovirus types A and B, human coronaviruses (HCoV) OC43, 229E/NL63] were investigated with those tests. In the study, 53.6% (375/700) of the patients were found to be infected with at least one virus and multiple respiratory virus infections were detected in 15.7% (59/375) of the positive cases, which were mostly (49/59, 83%) in pediatric patients. RSV and rhinovirus coinfections were the most prevalent (18

  14. Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh.

    PubMed

    Gerloff, Nancy A; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S; Luby, Stephen P; Wentworth, David E; Donis, Ruben O; Sturm-Ramirez, Katharine; Davis, C Todd

    2016-01-01

    Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

  15. Genetically Diverse Low Pathogenicity Avian Influenza A Virus Subtypes Co-Circulate among Poultry in Bangladesh

    PubMed Central

    Gerloff, Nancy A.; Khan, Salah Uddin; Zanders, Natosha; Balish, Amanda; Haider, Najmul; Islam, Ausraful; Chowdhury, Sukanta; Rahman, Mahmudur Ziaur; Haque, Ainul; Hosseini, Parviez; Gurley, Emily S.; Luby, Stephen P.; Wentworth, David E.; Donis, Ruben O.; Sturm-Ramirez, Katharine; Davis, C. Todd

    2016-01-01

    Influenza virus surveillance, poultry outbreak investigations and genomic sequencing were assessed to understand the ecology and evolution of low pathogenicity avian influenza (LPAI) A viruses in Bangladesh from 2007 to 2013. We analyzed 506 avian specimens collected from poultry in live bird markets and backyard flocks to identify influenza A viruses. Virus isolation-positive specimens (n = 50) were subtyped and their coding-complete genomes were sequenced. The most frequently identified subtypes among LPAI isolates were H9N2, H11N3, H4N6, and H1N1. Less frequently detected subtypes included H1N3, H2N4, H3N2, H3N6, H3N8, H4N2, H5N2, H6N1, H6N7, and H7N9. Gene sequences were compared to publicly available sequences using phylogenetic inference approaches. Among the 14 subtypes identified, the majority of viral gene segments were most closely related to poultry or wild bird viruses commonly found in Southeast Asia, Europe, and/or northern Africa. LPAI subtypes were distributed over several geographic locations in Bangladesh, and surface and internal protein gene segments clustered phylogenetically with a diverse number of viral subtypes suggesting extensive reassortment among these LPAI viruses. H9N2 subtype viruses differed from other LPAI subtypes because genes from these viruses consistently clustered together, indicating this subtype is enzootic in Bangladesh. The H9N2 strains identified in Bangladesh were phylogenetically and antigenically related to previous human-derived H9N2 viruses detected in Bangladesh representing a potential source for human infection. In contrast, the circulating LPAI H5N2 and H7N9 viruses were both phylogenetically and antigenically unrelated to H5 viruses identified previously in humans in Bangladesh and H7N9 strains isolated from humans in China. In Bangladesh, domestic poultry sold in live bird markets carried a wide range of LPAI virus subtypes and a high diversity of genotypes. These findings, combined with the seven year

  16. Prevalence and subtypes of influenza A viruses in wild waterfowl in Norway 2006-2007.

    PubMed

    Germundsson, Anna; Madslien, Knut I; Hjortaas, Monika Jankowska; Handeland, Kjell; Jonassen, Christine Monceyron

    2010-01-01

    The prevalence of influenza A virus infection, and the distribution of different subtypes of the virus, were studied in 1529 ducks and 1213 gulls shot during ordinary hunting from August to December in two consecutive years, 2006 and 2007, in Norway. The study was based on molecular screening of cloacal and tracheal swabs, using a pan-influenza A RT-PCR. Samples found to be positive for influenza A virus were screened for the H5 subtype, using a H5 specific RT-PCR, and, if negative, further subtyped by a RT-PCR for the 3'-part of the hemagglutinin (HA) gene, encompassing almost the entire HA2, and the full-length of the neuraminidase (NA) gene, followed by sequencing and characterization. The highest prevalence (12.8%) of infection was found in dabbling ducks (Eurasian Wigeon, Common Teal and Mallard). Diving ducks (Common Goldeneye, Common Merganser, Red-breasted Merganser, Common Scoter, Common Eider and Tufted Duck) showed a lower prevalence (4.1%). In gulls (Common Gull, Herring Gull, Black-headed Gull, Lesser Black-headed Gull, Great Black-backed Gull and Kittiwake) the prevalence of influenza A virus was 6.1%. The infection prevalence peaked during October for ducks, and October/November for gulls. From the 16 hemagglutinin subtypes known to infect wild birds, 13 were detected in this study. Low pathogenic H5 was found in 17 dabbling ducks and one gull. PMID:20426812

  17. Rapid semiautomated subtyping of influenza virus species during the 2009 swine origin influenza A H1N1 virus epidemic in Milwaukee, Wisconsin.

    PubMed

    Bose, Michael E; Beck, Eric T; Ledeboer, Nate; Kehl, Sue C; Jurgens, Lisa A; Patitucci, Teresa; Witt, Lorraine; LaGue, Elizabeth; Darga, Patrick; He, Jie; Fan, Jiang; Kumar, Swati; Henrickson, Kelly J

    2009-09-01

    In the spring of 2009, a novel influenza A (H1N1) virus (swine origin influenza virus [S-OIV]) emerged and began causing a large outbreak of illness in Milwaukee, WI. Our group at the Midwest Respiratory Virus Program laboratory developed a semiautomated real-time multiplex reverse transcription-PCR assay (Seasonal), employing the NucliSENS easyMAG system (bioMérieux, Durham, NC) and a Raider thermocycler (HandyLab Inc., Ann Arbor, MI), that typed influenza A virus, influenza B virus, and respiratory syncytial virus (RSV) and subtyped influenza A virus into the currently circulating H1 and H3 subtypes, as well as a similar assay that identified H1 of S-OIV. The Seasonal and H1 S-OIV assays demonstrated analytical limits of detection of <50 50% tissue culture infective doses/ml and 3 to 30 input copies, respectively. Testing of the analytical specificities revealed no cross-reactivity with 41 and 26 different common organisms and demonstrated outstanding reproducibility of results. Clinical testing showed 95% sensitivity for influenza A virus and influenza B virus and 95 and 97% specificity compared to tissue culture. Comparisons of results from other molecular tests showed levels of positive agreement with the Seasonal and H1 S-OIV assay results of 99 and 100% and levels of negative agreement of 98 and 100%. This study has demonstrated the use of a semiautomated system for sensitive, specific, and rapid detection of influenza A virus, influenza B virus, and RSV and subtyping of influenza A virus into human H1 and H3 and S-OIV strains. This assay/system performed well in clinical testing of regular seasonal influenza virus subtypes and was outstanding during the 2009 Milwaukee S-OIV infection outbreak. This recent outbreak of infection with a novel influenza A (H1N1) virus also demonstrates the importance of quickly distributing information on new agents and of having rapid influenza virus subtyping assays widely available for clinical and public health decisions

  18. Receptor-Binding Profiles of H7 Subtype Influenza Viruses in Different Host Species

    PubMed Central

    Gambaryan, Alexandra S.; Matrosovich, Tatyana Y.; Philipp, Jennifer; Munster, Vincent J.; Fouchier, Ron A. M.; Cattoli, Giovanni; Capua, Ilaria; Krauss, Scott L.; Webster, Robert G.; Banks, Jill; Bovin, Nicolai V.; Klenk, Hans-Dieter

    2012-01-01

    Influenza viruses of gallinaceous poultry and wild aquatic birds usually have distinguishable receptor-binding properties. Here we used a panel of synthetic sialylglycopolymers and solid-phase receptor-binding assays to characterize receptor-binding profiles of about 70 H7 influenza viruses isolated from aquatic birds, land-based poultry, and horses in Eurasia and America. Unlike typical duck influenza viruses with non-H7 hemagglutinin (HA), all avian H7 influenza viruses, irrespective of the host species, displayed a poultry-virus-like binding specificity, i.e., preferential binding to sulfated oligosaccharides Neu5Acα2-3Galβ1-4(6-O-HSO3)GlcNAc and Neu5Acα2-3Galβ1-4(Fucα1-3)(6-O-HSO3)GlcNAc. This phenotype correlated with the unique amino acid sequence of the amino acid 185 to 189 loop of H7 HA and seemed to be dependent on ionic interactions between the sulfate group of the receptor and Lys193 and on the lack of sterical clashes between the fucose residue and Gln222. Many North American and Eurasian H7 influenza viruses displayed weak but detectable binding to the human-type receptor moiety Neu5Acα2-6Galβ1-4GlcNAc, highlighting the potential of H7 influenza viruses for avian-to-human transmission. Equine H7 influenza viruses differed from other viruses by preferential binding to the N-glycolyl form of sialic acid. Our data suggest that the receptor-binding site of contemporary H7 influenza viruses in aquatic and terrestrial birds was formed after the introduction of their common precursor from ducks to a new host, presumably, gallinaceous poultry. The uniformity of the receptor-binding profile of H7 influenza viruses in various wild and domestic birds indicates that there is no strong receptor-mediated host range restriction in birds on viruses with this HA subtype. This notion agrees with repeated interspecies transmission of H7 influenza viruses from aquatic birds to poultry. PMID:22345462

  19. Protection Against H7 Subtype Influenza Virus Infection in Mice by Passive Transfer of Neutralizing Monoclonal Antibody.

    PubMed

    Zhang, Zhuo; Liu, Ming; Zheng, Shimin

    2015-10-01

    H7 subtype influenza viruses pose serious threats to both the poultry industry and public health. Recent human infections of avian H7N9 influenza viruses with substantial morbidity and mortality have raised concerns about this virus becoming a potential pandemic pathogen. Neutralizing antibodies have been proven to be highly effective in blocking influenza virus infections. In this study, in order to develop an antibody-based immunoprophylaxis against H7 subtype influenza virus, we first generated a neutralizing monoclonal antibody (MAb) by using a pseudotyped lentiviral vector carrying the hemagglutinin protein of H7 subtype influenza virus. In vitro studies demonstrated that this neutralizing MAb completely inhibited the infection of an H7 subtype influenza virus to cells. The protective efficacy of this MAb was then further tested in a mouse model. It was shown that passive immunization of this MAb protected mice from local virus challenge. Results of the current study lay a foundation for the development of neutralizing MAb-mediated prophylactic strategies to combat human H7 influenza virus infections. PMID:26492625

  20. Matrix protein 2 vaccination and protection against influenza viruses, including subtype H5N1.

    PubMed

    Tompkins, Stephen Mark; Zhao, Zi-Shan; Lo, Chia-Yun; Misplon, Julia A; Liu, Teresa; Ye, Zhiping; Hogan, Robert J; Wu, Zhengqi; Benton, Kimberly A; Tumpey, Terrence M; Epstein, Suzanne L

    2007-03-01

    Changes in influenza viruses require regular reformulation of strain-specific influenza vaccines. Vaccines based on conserved antigens provide broader protection. Influenza matrix protein 2 (M2) is highly conserved across influenza A subtypes. To evaluate its efficacy as a vaccine candidate, we vaccinated mice with M2 peptide of a widely shared consensus sequence. This vaccination induced antibodies that cross-reacted with divergent M2 peptide from an H5N1 subtype. A DNA vaccine expressing full-length consensus-sequence M2 (M2-DNA) induced M2-specific antibody responses and protected against challenge with lethal influenza. Mice primed with M2-DNA and then boosted with recombinant adenovirus expressing M2 (M2-Ad) had enhanced antibody responses that crossreacted with human and avian M2 sequences and produced T-cell responses. This M2 prime-boost vaccination conferred broad protection against challenge with lethal influenza A, including an H5N1 strain. Vaccination with M2, with key sequences represented, may provide broad protection against influenza A. PMID:17552096

  1. Prevalence of multiple subtypes of influenza A virus in Japanese wild raccoons.

    PubMed

    Yamaguchi, Emi; Sashika, Mariko; Fujii, Kei; Kobayashi, Kohei; Bui, Vuong Nghia; Ogawa, Haruko; Imai, Kunitoshi

    2014-08-30

    Raccoons (Procyon lotor), which are not native to Japan, have been suspected to transmit various pathogens by frequent intrusion into agricultural and residential areas. To determine influenza A virus seropositivity in raccoons in Japan, we examined a total of 634 raccoons captured in 19 towns (A-S) from 2009 to 2012. Agar gel precipitation tests showed that the antibody prevalence was 1.89% (12/634). All positive raccoons were captured in three towns (A-C) located within a radius of approximately 30km, and 75% had antibodies to multiple subtypes (H1, H3-5, N1, N6, and N8). H3 and N8 antibodies were most frequently detected (75%). Among all the raccoons captured, 67% (8/12) were found in town A in 2009 and 2010, and all five raccoons captured in 2010 had H3 and N8 antibodies, suggesting that transmission of the subtype might occur. H5 and N1 antibodies were also detected in two raccoons captured in town A. Virus neutralization tests examining the highly pathogenic avian influenza virus (HPAIV) H5N1 subtype (four isolates of which have been detected in Japan to date) and the low PAIV (LPAIV) H5N3 subtype showed that raccoon sera highly cross-reacted with three H5N1 strains (clade 2.5: Ck/Yamaguchi/7/04; clade 2.3.2.1: Whooper swan/Hokkaido/1/08 and Whooper swan/Hamanaka/11), while they displayed a low cross-reactivity with the antisera to the clade 2.2 virus (Ck/Miyazaki/K11/07) and H5N3 LPAIV (Whistling swan/Shimane/499/83). Thus, the origin of the H5N1 virus was not clearly defined. The viral M gene was detected in four antibody-negative raccoons captured in three towns by real-time reverse transcription-polymerase chain reaction (rRT-PCR) with high Ct values, although no virus was isolated. This study is the first report showing that raccoons of Japan were infected with multiple subtypes of influenza A virus, including H5N1. It remains to be elucidated how raccoons play a role in persistence of influenza A virus in nature and if they could pose risks to animal

  2. Newly Emergent Highly Pathogenic H5N9 Subtype Avian Influenza A Virus

    PubMed Central

    Yu, Yang; Wang, Xingbo; Jin, Tao; Wang, Hailong; Si, Weiying; Yang, Hui; Wu, Jiusheng; Yan, Yan; Liu, Guang; Sang, Xiaoyu; Wu, Xiaopeng; Gao, Yuwei; Xia, Xianzhu; Yu, Xinfen; Pan, Jingcao; Gao, George F.

    2015-01-01

    ABSTRACT The novel H7N9 avian influenza virus (AIV) was demonstrated to cause severe human respiratory infections in China. Here, we examined poultry specimens from live bird markets linked to human H7N9 infection in Hangzhou, China. Metagenomic sequencing revealed mixed subtypes (H5, H7, H9, N1, N2, and N9). Subsequently, AIV subtypes H5N9, H7N9, and H9N2 were isolated. Evolutionary analysis showed that the hemagglutinin gene of the novel H5N9 virus originated from A/Muscovy duck/Vietnam/LBM227/2012 (H5N1), which belongs to clade 2.3.2.1. The neuraminidase gene of the novel H5N9 virus originated from human-infective A/Hangzhou/1/2013 (H7N9). The six internal genes were similar to those of other H5N1, H7N9, and H9N2 virus strains. The virus harbored the PQRERRRKR/GL motif characteristic of highly pathogenic AIVs at the HA cleavage site. Receptor-binding experiments demonstrated that the virus binds α-2,3 sialic acid but not α-2,6 sialic acid. Identically, pathogenicity experiments also showed that the virus caused low mortality rates in mice. This newly isolated H5N9 virus is a highly pathogenic reassortant virus originating from H5N1, H7N9, and H9N2 subtypes. Live bird markets represent a potential transmission risk to public health and the poultry industry. IMPORTANCE This investigation confirms that the novel H5N9 subtype avian influenza A virus is a reassortant strain originating from H5N1, H7N9, and H9N2 subtypes and is totally different from the H5N9 viruses reported before. The novel H5N9 virus acquired a highly pathogenic H5 gene and an N9 gene from human-infecting subtype H7N9 but caused low mortality rates in mice. Whether this novel H5N9 virus will cause human infections from its avian host and become a pandemic subtype is not known yet. It is therefore imperative to assess the risk of emergence of this novel reassortant virus with potential transmissibility to public health. PMID:26085150

  3. Genetic and antigenic relatedness of H3 subtype influenza A viruses isolated from avian and mammalian species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Turkeys are susceptible to some swine influenza viruses based on natural and experimental transmissions of H1 and H3 subtype viruses from swine to turkeys. In 2004, we isolated triple reassortant H3N2 viruses from turkey breeder hens in Ohio and Illinois. These H3N2 viruses are currently the domin...

  4. Neutrality, Cross-Immunity and Subtype Dominance in Avian Influenza Viruses

    PubMed Central

    Brown, Vicki L.; Drake, John M.; Barton, Heather D.; Stallknecht, David E.; Brown, Justin D.; Rohani, Pejman

    2014-01-01

    Avian influenza viruses (AIVs) are considered a threat for their potential to seed human influenza pandemics. Despite their acknowledged importance, there are significant unknowns regarding AIV transmission dynamics in their natural hosts, wild birds. Of particular interest is the difference in subtype dynamics between human and bird populations–in human populations, typically only two or three subtypes cocirculate, while avian populations are capable of simultaneously hosting a multitude of subtypes. One species in particular–ruddy turnstones (Arenaria interpres)–has been found to harbour a very wide range of AIV subtypes, which could make them a key player in the spread of new subtypes in wild bird populations. Very little is known about the mechanisms that drive subtype dynamics in this species, and here we address this gap in our knowledge. Taking advantage of two independent sources of data collected from ruddy turnstones in Delaware Bay, USA, we examine patterns of subtype diversity and dominance at this site. We compare these patterns to those produced by a stochastic, multi-strain transmission model to investigate possible mechanisms that are parsimonious with the observed subtype dynamics. We find, in agreement with earlier experimental work, that subtype differences are unnecessary to replicate the observed dynamics, and that neutrality alone is sufficient. We also evaluate the role of subtype cross-immunity and find that it is not necessary to generate patterns consistent with observations. This work offers new insights into the mechanisms behind subtype diversity and dominance in a species that has the potential to be a key player in AIV dynamics in wild bird populations. PMID:24586401

  5. Evidence for genetic variation of Eurasian avian influenza viruses, subtype H15: The first report of an H15N7 virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An avian influenza virus (AIV) subtype H15N7 was isolated in 2010 during wild bird surveillance conducted in Ukraine (A/mallard/Novomychalivka/2-23-12/10). This particular subtype combination has not been previously reported. Until now, only seven subtype H15 viruses have been isolated worldwide, ...

  6. Assessment of transmission, pathogenesis and adaptation of H2 subtype influenza viruses in ferrets.

    PubMed

    Pappas, Claudia; Yang, Hua; Carney, Paul J; Pearce, Melissa B; Katz, Jacqueline M; Stevens, James; Tumpey, Terrence M

    2015-03-01

    After their disappearance from the human population in 1968, influenza H2 viruses have continued to circulate in the natural avian reservoir. The isolation of this virus subtype from multiple bird species as well as swine highlights the need to better understand the potential of these viruses to spread and cause disease in humans. Here we analyzed the virulence, transmissibility and receptor-binding preference of two avian influenza H2 viruses (H2N2 and H2N3) and compared them to a swine H2N3 (A/swine/Missouri/2124514/2006 [swMO]), and a human H2N2 (A/England/10/1967 [Eng/67]) virus using the ferret model as a mammalian host. Both avian H2 viruses possessed the capacity to spread efficiently between cohoused ferrets, and the swine (swMO) and human (Eng/67) viruses transmitted to naïve ferrets by respiratory droplets. Further characterization of the swMO hemagglutinin (HA) by x-ray crystallography and glycan microarray array identified receptor-specific adaptive mutations. As influenza virus quasispecies dynamics during transmission have not been well characterized, we sequenced nasal washes collected during transmission studies to better understand experimental adaptation of H2 HA. The avian H2 viruses isolated from ferret nasal washes contained mutations in the HA1, including a Gln226Leu substitution, which is a mutation associated with α2,6 sialic acid (human-like) binding preference. These results suggest that the molecular structure of HA in viruses of the H2 subtype continue to have the potential to adapt to a mammalian host and become transmissible, after acquiring additional genetic markers. PMID:25659818

  7. Evidence for seasonal patterns in the relative abundance of avian influenza virus subtypes in blue-winged teal (Anas discors)

    USGS Publications Warehouse

    Ramey, Andrew M.; Poulson, Rebecca L.; González-Reiche, Ana S.; Wilcox, Benjamin R.; Walther, Patrick; Link, Paul; Carter, Deborah L.; Newsome, George M.; Müller, Maria L.; Berghaus, Roy D.; Perez, Daniel R.; Hall, Jeffrey S.; Stallknecht, David E.

    2014-01-01

    Seasonal dynamics of influenza A viruses (IAVs) are driven by host density and population immunity. Through an analysis of subtypic data for IAVs isolated from Blue-winged Teal (Anas discors), we present evidence for seasonal patterns in the relative abundance of viral subtypes in spring and summer/autumn.

  8. PB2 subunit of avian influenza virus subtype H9N2: a pandemic risk factor.

    PubMed

    Sediri, Hanna; Thiele, Swantje; Schwalm, Folker; Gabriel, Gülsah; Klenk, Hans-Dieter

    2016-01-01

    Avian influenza viruses of subtype H9N2 that are found worldwide are occasionally transmitted to humans and pigs. Furthermore, by co-circulating with other influenza subtypes, they can generate new viruses with the potential to also cause zoonotic infections, as observed in 1997 with H5N1 or more recently with H7N9 and H10N8 viruses. Comparative analysis of the adaptive mutations in polymerases of different viruses indicates that their impact on the phylogenetically related H9N2 and H7N9 polymerases is higher than on the non-related H7N7 and H1N1pdm09 polymerases. Analysis of polymerase reassortants composed of subunits of different viruses demonstrated that the efficient enhancement of polymerase activity by H9N2-PB2 does not depend on PA and PB1. These observations suggest that the PB2 subunit of the H9N2 polymerase has a high adaptive potential and may therefore be an important pandemic risk factor. PMID:26560088

  9. Cross-reactivity between avian influenza A (H7N9) virus and divergent H7 subtypic- and heterosubtypic influenza A viruses

    PubMed Central

    Guo, Li; Wang, Dayan; Zhou, Hongli; Wu, Chao; Gao, Xin; Xiao, Yan; Ren, Lili; Paranhos-Baccalà, Gláucia; Shu, Yuelong; Jin, Qi; Wang, Jianwei

    2016-01-01

    The number of human avian H7N9 influenza infections has been increasing in China. Understanding their antigenic and serologic relationships is crucial for developing diagnostic tools and vaccines. Here, we evaluated the cross-reactivities and neutralizing activities among H7 subtype influenza viruses and between H7N9 and heterosubtype influenza A viruses. We found strong cross-reactivities between H7N9 and divergent H7 subtypic viruses, including H7N2, H7N3, and H7N7. Antisera against H7N2, H7N3, and H7N7 could also effectively neutralize two distinct H7N9 strains. Two-way cross-reactivities exist within group 2, including H3 and H4, whereas one-way cross-reactivities were found across other groups, including H1, H10, H9, and H13. Our data indicate that the hemaglutinins from divergent H7 subtypes may facilitate the development of vaccines for distinct H7N9 infections. Moreover, serologic diagnoses for H7N9 infections need to consider possible interference from the cross-reactivity of H7N9 with other subtype influenza viruses. PMID:26907865

  10. Surveillance for influenza virus subtypes H1, H2 and H3 among wild birds in Ukraine in 2006-2012

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Influenza is one of the most important and unpredictable diseases of humans, other mammals and birds. Influenza virus of H1, H2, and H3 subtypes circulate in humans and cause seasonal influenza. Similar subtypes are also circulating in the natural reservoir, wild aquatic birds, and und...

  11. Replication and transmission of mammalian-adapted H9 subtype influenza virus in pigs and quail.

    PubMed

    Obadan, Adebimpe O; Kimble, Brian J; Rajao, Daniela; Lager, Kelly; Santos, Jefferson J S; Vincent, Amy; Perez, Daniel R

    2015-09-01

    Influenza A virus is a major pathogen of birds, swine and humans. Strains can jump between species in a process often requiring mutations and reassortment, resulting in outbreaks and, potentially, pandemics. H9N2 avian influenza is predominant in poultry across Asia and occasionally infects humans and swine. Pandemic H1N1 (H1N1pdm) is endemic in humans and swine and has a history of reassortment in pigs. Previous studies have shown the compatibility of H9N2 and H1N1pdm for reassortment in ferrets, a model for human infection and transmission. Here, the effects of ferret adaptation of H9 surface gene segments on the infectivity and transmission in at-risk natural hosts, specifically swine and quail, were analysed. Reassortant H9N1 and H9N2 viruses, carrying seven or six gene segments from H1N1pdm, showed infectivity and transmissibility in swine, unlike the wholly avian H9N2 virus with ferret-adapted surface genes. In quail, only the reassortant H9N2 with the six internal gene segments from the H1N1pdm strain was able to infect and transmit, although less efficiently than the wholly avian H9N2 virus with ferret-adapted surface genes. These results highlight that ferret-adapted mutations on the haemagglutinin of H9 subtype virus do not restrict the ability of the virus to infect swine and quail, and that the ability to transmit in these species depends on the context of the whole virus. As such, this study emphasizes the threat that H9N2 reassortant viruses pose to humans and agricultural species and the importance of the genetic constellation of the virus to its ability to replicate and transmit in natural hosts of influenza. PMID:25986634

  12. Replication and transmission of mammalian-adapted H9 subtype influenza virus in pigs and quail

    PubMed Central

    Obadan, Adebimpe O.; Kimble, Brian J.; Rajao, Daniela; Lager, Kelly; Santos, Jefferson J. S.; Vincent, Amy

    2015-01-01

    Influenza A virus is a major pathogen of birds, swine and humans. Strains can jump between species in a process often requiring mutations and reassortment, resulting in outbreaks and, potentially, pandemics. H9N2 avian influenza is predominant in poultry across Asia and occasionally infects humans and swine. Pandemic H1N1 (H1N1pdm) is endemic in humans and swine and has a history of reassortment in pigs. Previous studies have shown the compatibility of H9N2 and H1N1pdm for reassortment in ferrets, a model for human infection and transmission. Here, the effects of ferret adaptation of H9 surface gene segments on the infectivity and transmission in at-risk natural hosts, specifically swine and quail, were analysed. Reassortant H9N1 and H9N2 viruses, carrying seven or six gene segments from H1N1pdm, showed infectivity and transmissibility in swine, unlike the wholly avian H9N2 virus with ferret-adapted surface genes. In quail, only the reassortant H9N2 with the six internal gene segments from the H1N1pdm strain was able to infect and transmit, although less efficiently than the wholly avian H9N2 virus with ferret-adapted surface genes. These results highlight that ferret-adapted mutations on the haemagglutinin of H9 subtype virus do not restrict the ability of the virus to infect swine and quail, and that the ability to transmit in these species depends on the context of the whole virus. As such, this study emphasizes the threat that H9N2 reassortant viruses pose to humans and agricultural species and the importance of the genetic constellation of the virus to its ability to replicate and transmit in natural hosts of influenza. PMID:25986634

  13. Rapid molecular subtyping by reverse transcription polymerase chain reaction of the neuraminidase gene of avian influenza A viruses.

    PubMed

    Fereidouni, S R; Starick, E; Grund, C; Globig, A; Mettenleiter, T C; Beer, M; Harder, T

    2009-03-30

    Accurate identification of hemagglutinin (HA) and neuraminidase (NA) subtypes of influenza A viruses is an integral part of monitoring programs targeting avian influenza viruses (AIV). Use of highly sensitive molecular screening methods such as pan influenza-specific real-time RT-PCR (rRT-PCR) yields an increasing number of samples which are positive for AIV RNA but negative by virus isolation and, therefore, require molecular, instead of serological, subtyping. We developed specific RT-PCR assays for all known nine AIV NA subtypes. Validation using 43 reference isolates from different animal species revealed good performance characteristics regarding sensitivity and specificity. On basis of serial tenfold dilution series of reference isolates a benchmark value of C(t) 32 in an M gene-specific rRT-PCR became evident below which all nine NA subtypes were readily detectable by the subtype-specific RT-PCRs. For subtypes N1, N2, N4 and N6 detection was extended to dilutions with C(t) values of up to 35. Diagnostic applicability of the whole set of conventional NA-specific RT-PCRs was evaluated by analysis of 119 different diagnostic samples from wild birds which proved to be positive for AIV by M gene-specific rRT-PCR. Diagnostic sensitivity and specificity was confirmed by sequencing NA amplicons from 41 field isolates generated from this set and by NA inhibition assays. A universal molecular HA/NA subtyping algorithm for rRT-PCR positive avian influenza virus monitoring samples is proposed which may complement classical serological subtyping of influenza A virus isolates. PMID:19028027

  14. Single assay for simultaneous detection and differential identification of human and avian influenza virus types, subtypes, and emergent variants.

    PubMed

    Metzgar, David; Myers, Christopher A; Russell, Kevin L; Faix, Dennis; Blair, Patrick J; Brown, Jason; Vo, Scott; Swayne, David E; Thomas, Colleen; Stenger, David A; Lin, Baochuan; Malanoski, Anthony P; Wang, Zheng; Blaney, Kate M; Long, Nina C; Schnur, Joel M; Saad, Magdi D; Borsuk, Lisa A; Lichanska, Agnieszka M; Lorence, Matthew C; Weslowski, Brian; Schafer, Klaus O; Tibbetts, Clark

    2010-01-01

    For more than four decades the cause of most type A influenza virus infections of humans has been attributed to only two viral subtypes, A/H1N1 or A/H3N2. In contrast, avian and other vertebrate species are a reservoir of type A influenza virus genome diversity, hosting strains representing at least 120 of 144 combinations of 16 viral hemagglutinin and 9 viral neuraminidase subtypes. Viral genome segment reassortments and mutations emerging within this reservoir may spawn new influenza virus strains as imminent epidemic or pandemic threats to human health and poultry production. Traditional methods to detect and differentiate influenza virus subtypes are either time-consuming and labor-intensive (culture-based) or remarkably insensitive (antibody-based). Molecular diagnostic assays based upon reverse transcriptase-polymerase chain reaction (RT-PCR) have short assay cycle time, and high analytical sensitivity and specificity. However, none of these diagnostic tests determine viral gene nucleotide sequences to distinguish strains and variants of a detected pathogen from one specimen to the next. Decision-quality, strain- and variant-specific pathogen gene sequence information may be critical for public health, infection control, surveillance, epidemiology, or medical/veterinary treatment planning. The Resequencing Pathogen Microarray (RPM-Flu) is a robust, highly multiplexed and target gene sequencing-based alternative to both traditional culture- or biomarker-based diagnostic tests. RPM-Flu is a single, simultaneous differential diagnostic assay for all subtype combinations of type A influenza viruses and for 30 other viral and bacterial pathogens that may cause influenza-like illness. These other pathogen targets of RPM-Flu may co-infect and compound the morbidity and/or mortality of patients with influenza. The informative specificity of a single RPM-Flu test represents specimen-specific viral gene sequences as determinants of virus type, A/HN subtype, virulence

  15. Riems influenza a typing array (RITA): An RT-qPCR-based low density array for subtyping avian and mammalian influenza a viruses.

    PubMed

    Hoffmann, Bernd; Hoffmann, Donata; Henritzi, Dinah; Beer, Martin; Harder, Timm C

    2016-01-01

    Rapid and sensitive diagnostic approaches are of the utmost importance for the detection of humans and animals infected by specific influenza virus subtype(s). Cascade-like diagnostics starting with the use of pan-influenza assays and subsequent subtyping devices are normally used. Here, we demonstrated a novel low density array combining 32 TaqMan(®) real-time RT-PCR systems in parallel for the specific detection of the haemagglutinin (HA) and neuraminidase (NA) subtypes of avian and porcine hosts. The sensitivity of the newly developed system was compared with that of the pan-influenza assay, and the specificity of all RT-qPCRs was examined using a broad panel of 404 different influenza A virus isolates representing 45 different subtypes. Furthermore, we analysed the performance of the RT-qPCR assays with diagnostic samples obtained from wild birds and swine. Due to the open format of the array, adaptations to detect newly emerging influenza A virus strains can easily be integrated. The RITA array represents a competitive, fast and sensitive subtyping tool that requires neither new machinery nor additional training of staff in a lab where RT-qPCR is already established. PMID:27256976

  16. Riems influenza a typing array (RITA): An RT-qPCR-based low density array for subtyping avian and mammalian influenza a viruses

    PubMed Central

    Hoffmann, Bernd; Hoffmann, Donata; Henritzi, Dinah; Beer, Martin; Harder, Timm C.

    2016-01-01

    Rapid and sensitive diagnostic approaches are of the utmost importance for the detection of humans and animals infected by specific influenza virus subtype(s). Cascade-like diagnostics starting with the use of pan-influenza assays and subsequent subtyping devices are normally used. Here, we demonstrated a novel low density array combining 32 TaqMan® real-time RT-PCR systems in parallel for the specific detection of the haemagglutinin (HA) and neuraminidase (NA) subtypes of avian and porcine hosts. The sensitivity of the newly developed system was compared with that of the pan-influenza assay, and the specificity of all RT-qPCRs was examined using a broad panel of 404 different influenza A virus isolates representing 45 different subtypes. Furthermore, we analysed the performance of the RT-qPCR assays with diagnostic samples obtained from wild birds and swine. Due to the open format of the array, adaptations to detect newly emerging influenza A virus strains can easily be integrated. The RITA array represents a competitive, fast and sensitive subtyping tool that requires neither new machinery nor additional training of staff in a lab where RT-qPCR is already established. PMID:27256976

  17. Phylogenetic analysis and pathogenicity of H3 subtype avian influenza viruses isolated from live poultry markets in China

    PubMed Central

    Cui, Hongrui; Shi, Ying; Ruan, Tao; Li, Xuesong; Teng, Qiaoyang; Chen, Hongjun; Yang, Jianmei; Liu, Qinfang; Li, Zejun

    2016-01-01

    H3 subtype influenza A virus is one of the main subtypes that threats both public and animal health. However, the evolution and pathogenicity of H3 avian influenza virus (AIV) circulating in domestic birds in China remain largely unclear. In this study, seven H3 AIVs (four H3N2 and three H3N8) were isolated from poultry in live poultry market (LPM) in China. Phylogenetic analyses of full genomes showed that all viruses were clustered into Eurasian lineage, except N8 genes of two H3N8 isolates fell into North American lineage. Intriguingly, the N8 gene of one H3N8 and PB2, PB1, NP and NS of two H3N2 isolates have close relationship with those of the highly pathogenic H5N8 viruses circulating in Korea and United States, suggesting that the H3-like AIV may contribute internal genes to the highly pathogenic H5N8 viruses. Phylogenetic tree of HA gene and antigenic cross-reactivity results indicated that two antigenically different H3 viruses are circulating in LPM in China. Most of the H3 viruses replicated in mice lung and nasal turbinate without prior adaptation, and the representative H3 viruses infected chickens without causing clinical signs. The reassortment of H3 subtype influenza viruses warrants continuous surveillance in LPM in China. PMID:27270298

  18. Phylogenetic analysis and pathogenicity of H3 subtype avian influenza viruses isolated from live poultry markets in China.

    PubMed

    Cui, Hongrui; Shi, Ying; Ruan, Tao; Li, Xuesong; Teng, Qiaoyang; Chen, Hongjun; Yang, Jianmei; Liu, Qinfang; Li, Zejun

    2016-01-01

    H3 subtype influenza A virus is one of the main subtypes that threats both public and animal health. However, the evolution and pathogenicity of H3 avian influenza virus (AIV) circulating in domestic birds in China remain largely unclear. In this study, seven H3 AIVs (four H3N2 and three H3N8) were isolated from poultry in live poultry market (LPM) in China. Phylogenetic analyses of full genomes showed that all viruses were clustered into Eurasian lineage, except N8 genes of two H3N8 isolates fell into North American lineage. Intriguingly, the N8 gene of one H3N8 and PB2, PB1, NP and NS of two H3N2 isolates have close relationship with those of the highly pathogenic H5N8 viruses circulating in Korea and United States, suggesting that the H3-like AIV may contribute internal genes to the highly pathogenic H5N8 viruses. Phylogenetic tree of HA gene and antigenic cross-reactivity results indicated that two antigenically different H3 viruses are circulating in LPM in China. Most of the H3 viruses replicated in mice lung and nasal turbinate without prior adaptation, and the representative H3 viruses infected chickens without causing clinical signs. The reassortment of H3 subtype influenza viruses warrants continuous surveillance in LPM in China. PMID:27270298

  19. Visual detection of H3 subtype avian influenza viruses by reverse transcription loop-mediated isothermal amplification assay

    PubMed Central

    2011-01-01

    Background Recent epidemiological investigation of different HA subtypes of avian influenza viruses (AIVs) shows that the H3 subtype is the most predominant among low pathogenic AIVs (LPAIVs), and the seasonal variations in isolation of H3 subtype AIVs are consistent with that of human H3 subtype influenza viruses. Consequently, the development of a rapid, simple, sensitive detection method for H3 subtype AIVs is required. The loop-mediated isothermal amplification (LAMP) assay is a simple, rapid, sensitive and cost-effective nucleic acid amplification method that does not require any specialized equipment. Results A reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay was developed to detect the H3 subtype AIVs visually. Specific primer sets target the sequences of the hemagglutinin (HA) gene of H3 subtype AIVs were designed, and assay reaction conditions were optimized. The established assay was performed in a water bath for 50 minutes, and the amplification result was visualized directly as well as under ultraviolet (UV) light reflections. The detection limit of the RT-LAMP assay was 0.1pg total RNA of virus, which was one hundred-fold higher than that of RT-PCR. The results on specificity indicated that the assay had no cross-reactions with other subtype AIVs or avian respiratory pathogens. Furthermore, a total of 176 clinical samples collected from birds at the various live-bird markets (LBMs) were subjected to the H3-subtype-specific RT-LAMP (H3-RT-LAMP). Thirty-eight H3 subtype AIVs were identified from the 176 clinical samples that were consistent with that of virus isolation. Conclusions The newly developed H3-RT-LAMP assay is simple, sensitive, rapid and can identify H3 subtype AIVs visually. Consequently, it will be a very useful screening assay for the surveillance of H3 subtype AIVs in underequipped laboratories as well as in field conditions. PMID:21729297

  20. Evaluation of a commercial enzyme-linked immunosorbent assay for detection of antibodies against the H5 subtype of Influenza A virus in waterfowl

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Serologic tools for rapid testing of subtype-specific influenza A (IA) virus antibody in wild birds and poultry are limited. In the current study, the ID Screen Influenza H5 Antibody Competition enzyme-linked immunosorbent assay (ELISA) was tested for the detection of antibodies to the H5 subtype o...

  1. Isolation of mixed subtypes of influenza A virus from a bald eagle (Haliaeetus leucocephalus)

    PubMed Central

    2010-01-01

    From April 2007 to March 2008, cloacal swabs were obtained from 246 casualty raptors recovered by various wildlife rehabilitation centers in the United States. The swabs were placed in a virus transport medium and transported to the laboratory on ice packs. At the laboratory, the samples were pooled with each pool consisting of five samples. All pools (n = 50) were screened for the presence of avian influenza virus (AIV) using a real time reverse transcription-polymerase chain reaction (rRT-PCR); one of the pools was found positive. All five samples in this pool were tested individually by rRT-PCR; one sample from a bald eagle was found positive. This sample was inoculated in embryonated chicken eggs for virus isolation and a hemagglutinating virus was isolated. Complete genome sequencing of the isolate revealed a mixed infection with H1N1 and H2N1 subtypes. Further analysis revealed that the PB1-F2 gene sequence of H1N1 virus had the N66S virulence-associated substitution. Further studies on ecology and epidemiology of AIV in raptors are needed to help understand their role in the maintenance and evolution of AIV. PMID:20667110

  2. Isolation of mixed subtypes of influenza A virus from a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Goyal, Sagar M; Jindal, Naresh; Chander, Yogesh; Ramakrishnan, Muthanan A; Redig, Patrick T; Sreevatsan, Srinand

    2010-01-01

    From April 2007 to March 2008, cloacal swabs were obtained from 246 casualty raptors recovered by various wildlife rehabilitation centers in the United States. The swabs were placed in a virus transport medium and transported to the laboratory on ice packs. At the laboratory, the samples were pooled with each pool consisting of five samples. All pools (n = 50) were screened for the presence of avian influenza virus (AIV) using a real time reverse transcription-polymerase chain reaction (rRT-PCR); one of the pools was found positive. All five samples in this pool were tested individually by rRT-PCR; one sample from a bald eagle was found positive. This sample was inoculated in embryonated chicken eggs for virus isolation and a hemagglutinating virus was isolated. Complete genome sequencing of the isolate revealed a mixed infection with H1N1 and H2N1 subtypes. Further analysis revealed that the PB1-F2 gene sequence of H1N1 virus had the N66S virulence-associated substitution. Further studies on ecology and epidemiology of AIV in raptors are needed to help understand their role in the maintenance and evolution of AIV. PMID:20667110

  3. Continuing Reassortant of H5N6 Subtype Highly Pathogenic Avian Influenza Virus in Guangdong.

    PubMed

    Yuan, Runyu; Wang, Zheng; Kang, Yinfeng; Wu, Jie; Zou, Lirong; Liang, Lijun; Song, Yingchao; Zhang, Xin; Ni, Hanzhong; Lin, Jinyan; Ke, Changwen

    2016-01-01

    First identified in May 2014 in China's Sichuan Province, initial cases of H5N6 avian influenza virus (AIV) infection in humans raised great concerns about the virus's prevalence, origin, and development. To evaluate both AIV contamination in live poultry markets (LPMs) and the risk of AIV infection in humans, we have conducted surveillance of LPMs in Guangdong Province since 2013 as part of environmental sampling programs. With environmental samples associated with these LPMs, we performed genetic and phylogenetic analyses of 10 H5N6 AIVs isolated from different cities of Guangdong Province from different years. Results revealed that the H5N6 viruses were reassortants with hemagglutinin (HA) genes derived from clade 2.3.4.4 of H5-subtype AIV, yet neuraminidase (NA) genes derived from H6N6 AIV. Unlike the other seven H5N6 viruses isolated in first 7 months of 2014, all of which shared remarkable sequence similarity with the H5N1 AIV in all internal genes, the PB2 genes of GZ693, GZ670, and ZS558 more closely related to H6N6 AIV and the PB1 gene of GZ693 to the H3-subtype AIV. Phylogenetic analyses revealed that the environmental H5N6 AIV related closely to human H5N6 AIVs isolated in Guangdong. These results thus suggest that continued reassortment has enabled the emergence of a novel H5N6 virus in Guangdong, as well as highlight the potential risk of highly pathogenic H5N6 AIVs in the province. PMID:27148209

  4. Continuing Reassortant of H5N6 Subtype Highly Pathogenic Avian Influenza Virus in Guangdong

    PubMed Central

    Yuan, Runyu; Wang, Zheng; Kang, Yinfeng; Wu, Jie; Zou, Lirong; Liang, Lijun; Song, Yingchao; Zhang, Xin; Ni, Hanzhong; Lin, Jinyan; Ke, Changwen

    2016-01-01

    First identified in May 2014 in China's Sichuan Province, initial cases of H5N6 avian influenza virus (AIV) infection in humans raised great concerns about the virus's prevalence, origin, and development. To evaluate both AIV contamination in live poultry markets (LPMs) and the risk of AIV infection in humans, we have conducted surveillance of LPMs in Guangdong Province since 2013 as part of environmental sampling programs. With environmental samples associated with these LPMs, we performed genetic and phylogenetic analyses of 10 H5N6 AIVs isolated from different cities of Guangdong Province from different years. Results revealed that the H5N6 viruses were reassortants with hemagglutinin (HA) genes derived from clade 2.3.4.4 of H5-subtype AIV, yet neuraminidase (NA) genes derived from H6N6 AIV. Unlike the other seven H5N6 viruses isolated in first 7 months of 2014, all of which shared remarkable sequence similarity with the H5N1 AIV in all internal genes, the PB2 genes of GZ693, GZ670, and ZS558 more closely related to H6N6 AIV and the PB1 gene of GZ693 to the H3-subtype AIV. Phylogenetic analyses revealed that the environmental H5N6 AIV related closely to human H5N6 AIVs isolated in Guangdong. These results thus suggest that continued reassortment has enabled the emergence of a novel H5N6 virus in Guangdong, as well as highlight the potential risk of highly pathogenic H5N6 AIVs in the province. PMID:27148209

  5. Molecular characterization of H6 subtype influenza viruses in southern China from 2009 to 2011.

    PubMed

    Zou, Shumei; Gao, Rongbao; Zhang, Ye; Li, Xiaodan; Chen, Wenbing; Bai, Tian; Dong, Libo; Wang, Dayan; Shu, Yuelong

    2016-01-01

    H6 avian influenza viruses (AIVs), which are prevalent in domestic and wild birds in Eurasian countries, have been isolated from pigs, a dog and a human. Routine virological surveillance at live poultry markets or poultry farms was conducted in southern China from 2009 to 2011. This study investigated the genetic and antigenic characteristics, analyzed the receptor-binding properties and evaluated the kinetics of infectivity of the AIVs in A549, MDCK and PK15 cells. A total of 14 H6N6 and 2 H6N2 isolates were obtained from four provinces in southern China. Genetic analysis indicated two distinct hemagglutinin lineages of the H6 strains cocirculating in southern China, and these strains facilitated active evolution and reassortment among multiple influenza virus subtypes from different avian species in nature. None of these isolates grouped with the novel Taiwan H6N1 virus responsible for human infection. Receptor-binding specificity assays showed that five H6 AIVs may have acquired the ability to recognize human receptors. Growth kinetics experiments showed that EV/HB-JZ/02/10(H6N2) and EV/JX/15/10(H6N6) initially reproduced faster and achieved higher titers than other viruses, suggesting that enhanced binding to α-2,6-linked sialic acids correlated with increased viral replication in mammalian cells. Overall, the results emphasize the need for continued surveillance of H6 outbreaks and extensive characterization of H6 isolates to better understand genetic changes and their implications. PMID:27436363

  6. Surveillance of Influenza A Virus and Its Subtypes in Migratory Wild Birds of Nepal

    PubMed Central

    Sharma, Ajay; Bhatta, Tarka; Adhikari, Pratikshya; Sherchan, Adarsh Man; Shrestha, Bishwo; Bista, Manisha; Rajbhandari, Rajesh; Oberoi, Mohinder; Bisht, Khadak; Hero, Jean-Marc; Dissanayake, Ravi; Dhakal, Maheshwar; Hughes, Jane; Debnath, Nitish

    2015-01-01

    Nepal boarders India and China and all three countries lie within the Central Asian Flyway for migratory birds. Novel influenza A H7N9 caused human fatalities in China in 2013. Subclinical infections of influenza A H7N9 in birds and the potential for virus dispersal by migratory birds prompted this study to assess avian H7N9 viral intrusion into Nepal. Surveillance of influenza A virus in migratory birds was implemented in early 2014 with assistance from the Food and Agricultural Organization (FAO). Of 1811 environmental fecal samples collected from seven wetland migratory bird roosting areas, influenza A H9N2 was found in one sample from a ruddy shelduck in Koshi Tappu Wildlife Reserve located in southern Nepal. Avian H7N9 and other highly pathogenic avian influenza viruses were not detected. This study provides baseline data on the status of avian influenza virus in migratory bird populations in Nepal. PMID:26176773

  7. Antigenic characterization of H3 subtypes of avian influenza A viruses from North America

    USGS Publications Warehouse

    Bailey, Elizabeth; Long, Li-Pong; Zhao, Nan; Hall, Jeffrey S.; Baroch, John A; Nolting, Jaqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable.

  8. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America.

    PubMed

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S; Baroch, John A; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L; Pharr, G Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J; Wan, Xiu-Feng

    2016-05-01

    Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts, including avian, swine, equine, canine, and sea mammal species. These H3 viruses are both antigenically and genetically diverse. Here, we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about four units, and each unit corresponds to a 2 log 2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable. PMID:27309078

  9. Antigenic Characterization of H3 Subtypes of Avian Influenza A Viruses from North America

    PubMed Central

    Bailey, Elizabeth; Long, Li-Ping; Zhao, Nan; Hall, Jeffrey S.; Baroch, John A.; Nolting, Jacqueline; Senter, Lucy; Cunningham, Frederick L.; Pharr, G. Todd; Hanson, Larry; Slemons, Richard; DeLiberto, Thomas J.; Wan, Xiu-Feng

    2016-01-01

    SUMMARY Besides humans, H3 subtypes of influenza A viruses (IAVs) can infect various animal hosts including avian, swine, equine, canine, and sea mammals. These H3 viruses are both antigenically and genetically diverse. Here we characterized the antigenic diversity of contemporary H3 avian IAVs recovered from migratory birds in North America. Hemagglutination inhibition (HI) assays were performed on 37 H3 isolates of avian IAVs recovered from 2007 to 2011 using generated reference chicken sera. These isolates were recovered from samples taken in the Atlantic, Mississippi, Central, and Pacific waterfowl migration flyways. Antisera to all the tested H3 isolates cross-reacted with each other, and, to a lesser extent, with those to H3 canine and H3 equine IAVs. Antigenic cartography showed that the largest antigenic distance among the 37 avian IAVs is about 4 units, and each unit corresponds to a 2log2 difference in the HI titer. However, none of the tested H3 IAVs cross-reacted with ferret sera derived from contemporary swine and human IAVs. Our results showed that the H3 avian IAVs we tested lacked significant antigenic diversity, and these viruses were antigenically different from those circulating in swine and human populations. This suggests that H3 avian IAVs in North American waterfowl are antigenically relatively stable. PMID:27309078

  10. Highly Pathogenic Avian Influenza Virus Subtype H5N1 Escaping Neutralization: More than HA Variation

    PubMed Central

    Höper, Dirk; Kalthoff, Donata; Hoffmann, Bernd

    2012-01-01

    Influenza A viruses are one of the major threats in modern health care. Novel viruses arise due to antigenic drift and antigenic shift, leading to escape from the immune system and resulting in a serious problem for disease control. In order to investigate the escape process and to enable predictions of escape, we serially passaged influenza A H5N1 virus in vitro 100 times under immune pressure. The generated escape viruses were characterized phenotypically and in detail by full-genome deep sequencing. Mutations already found in natural isolates were detected, evidencing the in vivo relevance of the in vitro-induced amino acid substitutions. Additionally, several novel alterations were triggered. Altogether, the results imply that our in vitro system is suitable to study influenza A virus evolution and that it might even be possible to predict antigenic changes of influenza A viruses circulating in vaccinated populations. PMID:22090121

  11. Cleavage Activation of Human-adapted Influenza Virus Subtypes by Kallikrein-related Peptidases 5 and 12*

    PubMed Central

    Hamilton, Brian S.; Whittaker, Gary R.

    2013-01-01

    A critical step in the influenza virus replication cycle is the cleavage activation of the HA precursor. Cleavage activation of influenza HA enables fusion with the host endosome, allowing for release of the viral genome into the host cell. To date, studies have determined that HA activation is driven by trypsin-like host cell proteases, as well as yet to be identified bacterial proteases. Although the number of host proteases that can activate HA is growing, there is still uncertainty regarding which secreted proteases are able to support multicycle replication of influenza. In this study, we have determined that the kallikrein-related peptidases 5 and 12 are secreted from the human respiratory tract and have the ability to cleave and activate HA from the H1, H2, and H3 subtypes. Each peptidase appears to have a preference for particular influenza subtypes, with kallikrein 5 cleaving the H1 and H3 subtypes most efficiently and kallikrein 12 cleaving the H1 and H2 subtypes most efficiently. Cleavage analysis using HA cleavage site peptide mimics revealed that the amino acids neighboring the arginine cleavage site affect cleavage efficiency. Additionally, the thrombolytic zymogens plasminogen, urokinase, and plasma kallikrein have all been shown to cleave and activate influenza but are found circulating mainly as inactive precursors. Kallikrein 5 and kallikrein 12 were examined for their ability to activate the thrombolytic zymogens, and both resulted in activation of each zymogen, with kallikrein 12 being a more potent activator. Activation of the thrombolytic zymogens may therefore allow for both direct and indirect activation of the HA of human-adapted influenza viruses by kallikrein 5 and kallikrein 12. PMID:23612974

  12. Development of an immunochromatographic strip for rapid detection of H9 subtype avian influenza viruses.

    PubMed

    Peng, Fuhu; Wang, Zheng; Zhang, Shuhui; Wu, Renwei; Hu, Sishun; Li, Zili; Wang, Xiliang; Bi, Dingren

    2008-03-01

    An immunochromatographic strip was developed for the detection of the H9 subtype of avian influenza viruses (H9AIVs) in poultry, using two monoclonal antibodies (MAb), 4C4 for H9AIV hemagglutinin (HA) and 4D4 for nucleoprotein. The 4C4 MAb was labeled with colloidal gold as the detection reagent, and the 4D4 MAb was blotted on the test line while a goat anti-mouse antibody was used on the control line of the nitrocellulose membrane. In comparison with the HA and HA inhibition (HI) tests, the strip was specific for the detection of H9AIV, with a sensitivity at 0.25 HA units within 10 min. Storage of the strips at room temperature for 6 months or at 4 degrees C for 12 months did not change their sensitivity and specificity. Evaluation of the strip with experimental tracheal and cloacal swab samples collected from H9N2-infected chickens revealed that the strip detected the H9N2 viruses on day 3 postinoculation, earlier than the appearance of clinical symptoms. Application of the strip for the analysis of 157 tracheal or cloacal samples from potentially infected chickens on five poultry farms showed that four farms had chickens that were infected with H9AIV. Further characterization of 10 positive and 30 negative randomly selected samples showed that no single sample was false positive or negative, as determined by the standard virus isolation and HI assays. Therefore, the immunochromatographic strip for the detection of H9AIVs has high specificity, sensitivity, and stability. This finding, together with the advantages of rapid detection and easy operation and without the requirement for special skills and equipment, makes the strip suitable for onsite detection and the differentiation of H9AIVs from other viruses in poultry. PMID:18199737

  13. Isolation and identification of highly pathogenic avian influenza virus subtype H5N1 in peafowl (Pavo cristatus).

    PubMed

    Ismail, Mahmoud Moussa; Khan, Owais Ahmed; Cattoli, Giovanni; Lu, Huaguang

    2010-03-01

    An outbreak of highly pathogenic avian influenza (HPAI) virus subtype H5N1 was first diagnosed in a "backyard" flock of peafowl (Pavo cristatus) raised on palace premises in the Kingdom of Saudi Arabia in December 3, 2007. The flock consisted of 40 peafowl, and their ages ranged from 3 to 5 years old. Affected birds suffered from depression, anorexia, and white diarrhea. Four dead birds were submitted for HPAI diagnosis at the Central Veterinary Diagnostic Laboratory in Riyadh. Brain and liver tissues and tracheal and cloacal swabs were taken from the dead birds and processed for a real-time reverse transcriptase (RT)-PCR test and virus isolation in specific-pathogen-free embryonating chicken eggs. The H5N1 subtype of avian influenza virus was isolated from the four dead birds and identified by a real-time RT-PCR before and after egg inoculation. The virus isolates were characterized as HPAI H5N1 virus by sequencing analysis. Phylogenetic comparisons revealed that the H5N1 viruses isolated from peafowl belong to the genetic clade 2.2 according to the World Health Organization nomenclature. The peafowl H5N1 virus falls into 2.2.2 sublineage II and clusters with the H5N1 viruses isolated from poultry in Saudi Arabia in 2007-08. PMID:20521659

  14. Detection of Influenza Virus with Specific Subtype by Using Localized Surface Plasmons Excited on a Flat Metal Surface

    NASA Astrophysics Data System (ADS)

    Ning, Jun; Nagata, Kotaro; Ainai, Akira; Hasegawa, Hideki; Kano, Hiroshi

    2013-08-01

    We report on a method to determine subtype of influenza viruses by using surface plasmons localized in microscopic region on a flat metal surface. In this method, refractive index variation arisen from interactions between viruses and their monoclonal antibodies is measured. The developed sensor shows stability of refractive index in the order of 10-4 against sample exchange. In our experiment, A/H1N1 viruses are distinguished from A/H3N2 viruses by using monoclonal antibodies immobilized on the metal surface. Since the measurement probe has the volume of ˜6 al, the method has potential to handle multiple subtypes in the measurement of a sample with ultra small volume.

  15. Long-term variation in influenza A virus prevalence and subtype diversity in migratory mallards in northern Europe

    PubMed Central

    Latorre-Margalef, Neus; Tolf, Conny; Grosbois, Vladimir; Avril, Alexis; Bengtsson, Daniel; Wille, Michelle; Osterhaus, Albert D. M. E.; Fouchier, Ron A. M.; Olsen, Björn; Waldenström, Jonas

    2014-01-01

    Data on long-term circulation of pathogens in wildlife populations are seldom collected, and hence understanding of spatial–temporal variation in prevalence and genotypes is limited. Here, we analysed a long-term surveillance series on influenza A virus (IAV) in mallards collected at an important migratory stopover site from 2002 to 2010, and characterized seasonal dynamics in virus prevalence and subtype diversity. Prevalence dynamics were influenced by year, but retained a common pattern for all years whereby prevalence was low in spring and summer, but increased in early autumn with a first peak in August, and a second more pronounced peak during October–November. A total of 74 haemagglutinin (HA)/neuraminidase (NA) combinations were isolated, including all NA and most HA (H1–H12) subtypes. The most common subtype combinations were H4N6, H1N1, H2N3, H5N2, H6N2 and H11N9, and showed a clear linkage between specific HA and NA subtypes. Furthermore, there was a temporal structuring of subtypes within seasons based on HA phylogenetic relatedness. Dissimilar HA subtypes tended to have different temporal occurrence within seasons, where the subtypes that dominated in early autumn were rare in late autumn, and vice versa. This suggests that build-up of herd immunity affected IAV dynamics in this system. PMID:24573857

  16. Targeting the HA2 subunit of influenza A virus hemagglutinin via CD40L provides universal protection against diverse subtypes.

    PubMed

    Fan, X; Hashem, A M; Chen, Z; Li, C; Doyle, T; Zhang, Y; Yi, Y; Farnsworth, A; Xu, K; Li, Z; He, R; Li, X; Wang, J

    2015-01-01

    The influenza viral hemagglutinin (HA) is comprised of two subunits. Current influenza vaccine predominantly induces neutralizing antibodies (Abs) against the HA1 subunit, which is constantly evolving in unpredictable fashion. The other subunit, HA2, however, is highly conserved but largely shielded by the HA head domain. Thus, enhancing immune response against HA2 could potentially elicit broadly inhibitory Abs. We generated a recombinant adenovirus (rAd) encoding secreted fusion protein, consisting of codon-optimized HA2 subunit of influenza A/California/7/2009(H1N1) virus fused to a trimerized form of murine CD40L, and determined its ability of inducing protective immunity upon intranasal administration. We found that mice immunized with this recombinant viral vaccine were completely protected against lethal challenge with divergent influenza A virus subtypes including H1N1, H3N2, and H9N2. Codon-optimization of HA2 as well as the use of CD40L as a targeting ligand/molecular adjuvant were indispensable to enhance HA2-specific mucosal IgA and serum IgG levels. Moreover, induction of HA2-specific T-cell responses was dependent on CD40L, as rAd secreting HA2 subunit without CD40L failed to induce any significant levels of T-cell cytokines. Finally, sera obtained from immunized mice were capable of inhibiting 13 subtypes of influenza A viruses in vitro. These results provide proof of concept for a prototype HA2-based universal influenza vaccine. PMID:25052763

  17. Transmission of an H5N8-Subtype Highly Pathogenic Avian Influenza Virus from Infected Hens to Laid Eggs.

    PubMed

    Uchida, Yuko; Takemae, Nobuhiro; Tanikawa, Taichiro; Kanehira, Katsushi; Saito, Takehiko

    2016-06-01

    We showed here that an H5N8-subtype highly pathogenic avian influenza virus (HPAIV) was transmitted to both the internal contents and shells of eggs laid by white leghorn hens experimentally infected with the virus. Seven of eight HPAIV-infected hens laid eggs until 4 days postinoculation (dpi). The mean number of eggs laid per head daily decreased significantly from 0.58 before inoculation to 0.18 after viral inoculation. The virus was detected in the eggs laid by three of the seven hens. Viral transmission was detectable beginning on 3 dpi, and virus titers in tracheal and cloacal swabs from the hens that laid the contaminated eggs exceeded 2.9 log10 EID50. The level of viral replication and its timing when virus replicates enough to be detected in oviduct after virus inoculation appear to be key factors in the transmission of H5N8 HPAIV from infected hens to laid eggs. PMID:27309286

  18. Genome Sequence of a Novel H14N7 Subtype Influenza A Virus Isolated from a Blue-Winged Teal (Anas discors) Harvested in Texas, USA.

    PubMed

    Ramey, Andrew M; Reeves, Andrew B; Poulson, Rebecca L; Carter, Deborah L; Davis-Fields, Nicholas; Stallknecht, David E

    2016-01-01

    We report here the complete genome sequence of a novel H14N7 subtype influenza A virus (IAV) isolated from a blue-winged teal (Anas discors) harvested in Texas, USA. The genomic characteristics of this IAV strain with a previously undetected subtype combination suggest recent viral evolution within the New World wild-bird IAV reservoir. PMID:27284136

  19. Genome Sequence of a Novel H14N7 Subtype Influenza A Virus Isolated from a Blue-Winged Teal (Anas discors) Harvested in Texas, USA

    PubMed Central

    Reeves, Andrew B.; Poulson, Rebecca L.; Carter, Deborah L.; Davis-Fields, Nicholas; Stallknecht, David E.

    2016-01-01

    We report here the complete genome sequence of a novel H14N7 subtype influenza A virus (IAV) isolated from a blue-winged teal (Anas discors) harvested in Texas, USA. The genomic characteristics of this IAV strain with a previously undetected subtype combination suggest recent viral evolution within the New World wild-bird IAV reservoir. PMID:27284136

  20. Analytical validation of a real-time RT-PCR test for Pan-American lineage H7 subtype avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid detection of avian influenza virus and identification of the H5 and H7 hemagglutinin subtypes some of which are associated with high pathogenicity in poultry is critical for clinical diagnosis and wild bird monitoring programs. A real-time RT-PCR test for identification of the H7 subtype in N...

  1. Molecular Characterization of Subtype H11N9 Avian Influenza Virus Isolated from Shorebirds in Brazil.

    PubMed

    Hurtado, Renata; Fabrizio, Thomas; Vanstreels, Ralph Eric Thijl; Krauss, Scott; Webby, Richard J; Webster, Robert G; Durigon, Edison Luiz

    2015-01-01

    Migratory aquatic birds play an important role in the maintenance and spread of avian influenza viruses (AIV). Many species of aquatic migratory birds tend to use similar migration routes, also known as flyways, which serve as important circuits for the dissemination of AIV. In recent years there has been extensive surveillance of the virus in aquatic birds in the Northern Hemisphere; however in contrast only a few studies have been attempted to detect AIV in wild birds in South America. There are major flyways connecting South America to Central and North America, whereas avian migration routes between South America and the remaining continents are uncommon. As a result, it has been hypothesized that South American AIV strains would be most closely related to the strains from North America than to those from other regions in the world. We characterized the full genome of three AIV subtype H11N9 isolates obtained from ruddy turnstones (Arenaria interpres) on the Amazon coast of Brazil. For all gene segments, all three strains consistently clustered together within evolutionary lineages of AIV that had been previously described from aquatic birds in North America. In particular, the H11N9 isolates were remarkably closely related to AIV strains from shorebirds sampled at the Delaware Bay region, on the Northeastern coast of the USA, more than 5000 km away from where the isolates were retrieved. Additionally, there was also evidence of genetic similarity to AIV strains from ducks and teals from interior USA and Canada. These findings corroborate that migratory flyways of aquatic birds play an important role in determining the genetic structure of AIV in the Western hemisphere, with a strong epidemiological connectivity between North and South America. PMID:26689791

  2. Molecular Characterization of Subtype H11N9 Avian Influenza Virus Isolated from Shorebirds in Brazil

    PubMed Central

    Hurtado, Renata; Fabrizio, Thomas; Vanstreels, Ralph Eric Thijl; Krauss, Scott; Webby, Richard J.; Webster, Robert G.; Durigon, Edison Luiz

    2015-01-01

    Migratory aquatic birds play an important role in the maintenance and spread of avian influenza viruses (AIV). Many species of aquatic migratory birds tend to use similar migration routes, also known as flyways, which serve as important circuits for the dissemination of AIV. In recent years there has been extensive surveillance of the virus in aquatic birds in the Northern Hemisphere; however in contrast only a few studies have been attempted to detect AIV in wild birds in South America. There are major flyways connecting South America to Central and North America, whereas avian migration routes between South America and the remaining continents are uncommon. As a result, it has been hypothesized that South American AIV strains would be most closely related to the strains from North America than to those from other regions in the world. We characterized the full genome of three AIV subtype H11N9 isolates obtained from ruddy turnstones (Arenaria interpres) on the Amazon coast of Brazil. For all gene segments, all three strains consistently clustered together within evolutionary lineages of AIV that had been previously described from aquatic birds in North America. In particular, the H11N9 isolates were remarkably closely related to AIV strains from shorebirds sampled at the Delaware Bay region, on the Northeastern coast of the USA, more than 5000 km away from where the isolates were retrieved. Additionally, there was also evidence of genetic similarity to AIV strains from ducks and teals from interior USA and Canada. These findings corroborate that migratory flyways of aquatic birds play an important role in determining the genetic structure of AIV in the Western hemisphere, with a strong epidemiological connectivity between North and South America. PMID:26689791

  3. Evaluation of MChip with Historic Subtype H1N1 Influenza A Viruses, Including the 1918 “Spanish Flu” Strain▿

    PubMed Central

    Moore, Chad L.; Smagala, James A.; Smith, Catherine B.; Dawson, Erica D.; Cox, Nancy J.; Kuchta, Robert D.; Rowlen, Kathy L.

    2007-01-01

    The robustness of a recently developed diagnostic microarray for influenza, the MChip, was evaluated with 16 historic subtype H1N1 influenza A viruses (A/H1N1), including A/Brevig Mission/1/1918. The matrix gene segments from all 16 viruses were successfully detected on the array. An artificial neural network trained with temporally related A/H1N1 viruses identified A/Brevig Mission/1/1918 as influenza virus A/H1N1 with 94% probability. PMID:17855577

  4. [Development of a Real-Time Reverse Transcription PCR Assay System for Detection of Three Subtypes of Influenza A and Influenza B Viruses].

    PubMed

    Yanagita, Mitsutoshi; Kuwamura, Yoshitaka; Kinoshita, Satoru; Nakajima, Takashi; Tomizawa, Syuichi; Ozawa, Tetsuo

    2015-12-01

    We developed the initial real-time reverse transcription PCR assay system for seasonal influenza viruses in 2011. This prototype assay system could detect and identify specific influenza A virus subtypes[H1N1, H3N2 and (H1N1) pdm09] and influenza B virus. In the 2012-2013 season, our prototype PCR assay didn't work well because of point mutations occurred in the neuraminidase (NA) gene of the A (H3N2) strain. We improved the prototype assay by changing the target gene for A (H3N2) strain (2013 improved PCR assay). Moreover, we added the measurement system for the matrix (M) gene that was well conserved and common to all influenza A subtypes. In the 2013-2014 season, point mutations in the hemagglutinin (HA) gene of the A (H1N1) pdm09 strain lowered the sensitivity of the 2013 improved PCR assay, so that we changed the target gene for A (H1N1)pdm09 strain (2014 improved PCR assay). We analyzed swab samples from 1,721 patients in total by at least one of the three PCR assays we developed, and demonstrated that the PCR assays had excellent sensitivity and specificity compared with those of the commercially available rapid immunochromatography kit we used. In this study, the M gene was positive in all patients who were finally diagnosed as influenza A positive by 2013 or 2014 improved PCR assay. Therefore, measurement of the M gene, which is hardly to be affected by antigenic drift of influenza viruses, is thought to be useful in clinical practice. PMID:27089652

  5. Pyrrolidinobenzoic Acid Inhibitors of Influenza Virus Neuraminidase: the Hydrophobic Side Chain Influences Type A Subtype Selectivity

    PubMed Central

    Li, Yanwu; Silamkoti, Arundutt; Kolavi, Gundurao; Mou, Liyuan; Gulati, Shelly; Air, Gillian M.

    2012-01-01

    Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 vs N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza. PMID:22677529

  6. Pyrrolidinobenzoic acid inhibitors of influenza virus neuraminidase: the hydrophobic side chain influences type A subtype selectivity.

    PubMed

    Li, Yanwu; Silamkoti, Arundutt; Kolavi, Gundurao; Mou, Liyuan; Gulati, Shelly; Air, Gillian M; Brouillette, Wayne J

    2012-07-15

    Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 versus N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza. PMID:22677529

  7. Improved method for the isolation and sub-typing of avian influenza viruses from oropharyngeal samples of ducks.

    PubMed

    El Zowalaty, Mohamed E; Abin, Martha; Chander, Yogesh; Redig, Patrick T; Goyal, Sagar M

    2011-09-01

    Waterfowl are the natural reservoirs of avian influenza viruses (AIVs), from which the virus can spread to other species including humans, poultry, and swine. For the surveillance of AIV in their natural reservoir, most laboratories initially screen the samples using real-time reverse-transcriptase-polymerase chain reaction because of its high speed and sensitivity. Thereafter, virus isolation is used to isolate viruses from positive samples. Although many studies point to the need of testing both cloacal and oropharyngeal (OP) samples in AIV surveillance programs, most laboratories focus only on cloacal samples. This study was undertaken to determine the utility of OP samples as target samples in AIV surveillance programs under a strict cold chain of samples from the field to the laboratory. A total of 16 AIV (15.1%) were isolated from the 106 OP samples examined. Upon subtyping, four hemagglutinin subtypes (H1, H3, H4, and H6) and three neuraminidase subtypes (N1, N2, and N8) were detected in nine different combinations. Mixed infection with two different subtypes was found in four samples. No AIVs were isolated from the corresponding cloacal samples. These results highlight the fact that testing of properly frozen OP samples could add value to the understanding of the epidemiology and ecology of AIV in waterfowl populations. PMID:22017043

  8. Isolation of Single-Stranded DNA Aptamers That Distinguish Influenza Virus Hemagglutinin Subtype H1 from H5

    PubMed Central

    Yim, Sanggyu; Jeong, Yong-Joo

    2015-01-01

    Surface protein hemagglutinin (HA) mediates the binding of influenza virus to host cell receptors containing sialic acid, facilitating the entry of the virus into host cells. Therefore, the HA protein is regarded as a suitable target for the development of influenza virus detection devices. In this study, we isolated single-stranded DNA (ssDNA) aptamers binding to the HA1 subunit of subtype H1 (H1-HA1), but not to the HA1 subunit of subtype H5 (H5-HA1), using a counter-systematic evolution of ligands by exponential enrichment (counter-SELEX) procedure. Enzyme-linked immunosorbent assay and surface plasmon resonance studies showed that the selected aptamers bind tightly to H1-HA1 with dissociation constants in the nanomolar range. Western blot analysis demonstrated that the aptamers were binding to H1-HA1 in a concentration-dependent manner, yet were not binding to H5-HA1. Interestingly, the selected aptamers contained G-rich sequences in the central random nucleotides region. Further biophysical analysis showed that the G-rich sequences formed a G-quadruplex structure, which is a distinctive structure compared to the starting ssDNA library. Using flow cytometry analysis, we found that the aptamers did not bind to the receptor-binding site of H1-HA1. These results indicate that the selected aptamers that distinguish H1-HA1 from H5-HA1 can be developed as unique probes for the detection of the H1 subtype of influenza virus. PMID:25901739

  9. European Surveillance Network for Influenza in Pigs: Surveillance Programs, Diagnostic Tools and Swine Influenza Virus Subtypes Identified in 14 European Countries from 2010 to 2013

    PubMed Central

    Simon, Gaëlle; Larsen, Lars E.; Dürrwald, Ralf; Foni, Emanuela; Harder, Timm; Van Reeth, Kristien; Markowska-Daniel, Iwona; Reid, Scott M.; Dan, Adam; Maldonado, Jaime; Huovilainen, Anita; Billinis, Charalambos; Davidson, Irit; Agüero, Montserrat; Vila, Thaïs; Hervé, Séverine; Breum, Solvej Østergaard; Chiapponi, Chiara; Urbaniak, Kinga; Kyriakis, Constantinos S.; Brown, Ian H.; Loeffen, Willie

    2014-01-01

    Swine influenza causes concern for global veterinary and public health officials. In continuing two previous networks that initiated the surveillance of swine influenza viruses (SIVs) circulating in European pigs between 2001 and 2008, a third European Surveillance Network for Influenza in Pigs (ESNIP3, 2010–2013) aimed to expand widely the knowledge of the epidemiology of European SIVs. ESNIP3 stimulated programs of harmonized SIV surveillance in European countries and supported the coordination of appropriate diagnostic tools and subtyping methods. Thus, an extensive virological monitoring, mainly conducted through passive surveillance programs, resulted in the examination of more than 9 000 herds in 17 countries. Influenza A viruses were detected in 31% of herds examined from which 1887 viruses were preliminary characterized. The dominating subtypes were the three European enzootic SIVs: avian-like swine H1N1 (53.6%), human-like reassortant swine H1N2 (13%) and human-like reassortant swine H3N2 (9.1%), as well as pandemic A/H1N1 2009 (H1N1pdm) virus (10.3%). Viruses from these four lineages co-circulated in several countries but with very different relative levels of incidence. For instance, the H3N2 subtype was not detected at all in some geographic areas whereas it was still prevalent in other parts of Europe. Interestingly, H3N2-free areas were those that exhibited highest frequencies of circulating H1N2 viruses. H1N1pdm viruses were isolated at an increasing incidence in some countries from 2010 to 2013, indicating that this subtype has become established in the European pig population. Finally, 13.9% of the viruses represented reassortants between these four lineages, especially between previous enzootic SIVs and H1N1pdm. These novel viruses were detected at the same time in several countries, with increasing prevalence. Some of them might become established in pig herds, causing implications for zoonotic infections. PMID:25542013

  10. Human monoclonal ScFv specific to NS1 protein inhibits replication of influenza viruses across types and subtypes.

    PubMed

    Yodsheewan, Rungrueang; Maneewatch, Santi; Srimanote, Potjanee; Thueng-In, Kanyarat; Songserm, Thaweesak; Dong-Din-On, Fonthip; Bangphoomi, Kunan; Sookrung, Nitat; Choowongkomon, Kiattawee; Chaicumpa, Wanpen

    2013-10-01

    Currently, there is a need of new anti-influenza agents that target influenza virus proteins other than ion channel M2 and neuraminidase. Non-structural protein-1 (NS1) is a highly conserved multifunctional protein which is indispensable for the virus replication cycle. In this study, fully human single chain antibody fragments (HuScFv) that bound specifically to recombinant and native NS1 were produced from three huscfv-phagemid transformed Escherichia coli clones (nos. 3, 10 and 11) selected from a human ScFv phage display library. Western blot analysis, mimotope searching/epitope identification, homology modeling/molecular docking and phage mimotope ELISA inhibition indicated that HuScFv of clone no. 3 reacted with NS1 R domain important for host innate immunity suppression; HuScFv of clone nos. 10 and 11 bound to E domain sites necessary for NS1 binding to the host eIF4GI and CPSF30, respectively. The HuScFv of all clones could enter the influenza virus infected cells and interfered with the NS1 activities leading to replication inhibition of viruses belonging to various heterologous A subtypes and type B by 2-64-fold as semi-quantified by hemagglutination assay. Influenza virus infected cells treated with representative HuScFv (clone 10) had up-expression of IRF3 and IFN-β genes by 14.75 and 4.95-fold, respectively, in comparison with the controls, indicating that the antibodies could restore the host innate immune response. The fully human single chain antibodies have high potential for developing further as a safe (adjunctive) therapeutic agent for mitigating, if not abrogating, severe symptoms of influenza. PMID:23928258

  11. Influenza-A Viruses in Ducks in Northwestern Minnesota: Fine Scale Spatial and Temporal Variation in Prevalence and Subtype Diversity

    PubMed Central

    Wilcox, Benjamin R.; Knutsen, Gregory A.; Berdeen, James; Goekjian, Virginia; Poulson, Rebecca; Goyal, Sagar; Sreevatsan, Srinand; Cardona, Carol; Berghaus, Roy D.; Swayne, David E.; Yabsley, Michael J.; Stallknecht, David E.

    2011-01-01

    Waterfowl from northwestern Minnesota were sampled by cloacal swabbing for Avian Influenza Virus (AIV) from July – October in 2007 and 2008. AIV was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.9%) of 2,452 ducks in 2008. Prevalence of AIV peaked in late summer. We detected 27 AIV subtypes during 2007 and 31 during 2008. Ten hemagglutinin (HA) subtypes were detected each year (i.e., H1, 3–8, and 10–12 during 2007; H1-8, 10 and 11 during 2008). All neuraminidase (NA) subtypes were detected during each year of the study. Subtype diversity varied between years and increased with prevalence into September. Predominant subtypes during 2007 (comprising ≥5% of subtype diversity) included H1N1, H3N6, H3N8, H4N6, H7N3, H10N7, and H11N9. Predominant subtypes during 2008 included H3N6, H3N8, H4N6, H4N8, H6N1, and H10N7. Additionally, within each HA subtype, the same predominant HA/NA subtype combinations were detected each year and included H1N1, H3N8, H4N6, H5N2, H6N1, H7N3, H8N4, H10N7, and H11N9. The H2N3 and H12N5 viruses also predominated within the H2 and H12 subtypes, respectively, but only were detected during a single year (H2 and H12 viruses were not detected during 2007 and 2008, respectively). Mallards were the predominant species sampled (63.7% of the total), and 531 AIV were isolated from this species (80.5% of the total isolates). Mallard data collected during both years adequately described the observed temporal and spatial prevalence from the total sample and also adequately represented subtype diversity. Juvenile mallards also were adequate in describing the temporal and spatial prevalence of AIV as well as subtype diversity. PMID:21931636

  12. Antigenic and Genetic Evolution of Low-Pathogenicity Avian Influenza Viruses of Subtype H7N3 following Heterologous Vaccination

    PubMed Central

    Xu, Yifei; Long, Li-Ping; Capua, Ilaria; Wan, Xiu-Feng

    2014-01-01

    Outbreaks of low-pathogenicity avian influenza (LPAI) viruses of the H7N3 subtype were first detected in Italy in October 2002, and the virus continued to circulate between 2002 and 2004 in a densely populated poultry area in the northeast portion of that country. This virus circulated in unvaccinated and vaccinated poultry farms, and the infection was controlled in August 2003 by culling, control of movements, improved biosecurity, and heterologous vaccination. In 2004, H7N3 reoccurred in vaccinated poultry farms in which infection had been successfully controlled by the vaccination program. To shed light on this occurrence and the temporal pattern and genetic basis of antigenic drift for avian influenza viruses (AIVs) in the absence and presence of heterologous vaccination, a collection of H7N3 viruses isolated in 2002 and 2004 were characterized genetically and antigenically. Molecular analysis showed that viruses isolated in the 2004 outbreaks after the implementation of vaccination had acquired specific amino acid signatures, most of which were located at reported antibody binding sites of the hemagglutinin (HA) protein. Antigenic characterization of these 2004 isolates showed that they were antigenically different from those isolated prior to the implementation of vaccination. This is the first report on antigenic and genetic evolution of H7 LPAI viruses following the application of heterologous vaccination in poultry. These findings may have an impact on control strategies to combat AI infections in poultry based on vaccination. PMID:24554694

  13. Protection against multiple subtypes of influenza viruses by virus-like particle vaccines based on a hemagglutinin conserved epitope.

    PubMed

    Chen, Shaoheng; Zheng, Dan; Li, Changgui; Zhang, Wenjie; Xu, Wenting; Liu, Xueying; Fang, Fang; Chen, Ze

    2015-01-01

    We selected the conserved sequence in the stalk region of influenza virus hemagglutinin (HA) trimmer, the long alpha helix (LAH), as the vaccine candidate sequence, and inserted it into the major immunodominant region (MIR) of hepatitis B virus core protein (HBc), and, by using the E. coli expression system, we prepared a recombinant protein vaccine LAH-HBc in the form of virus-like particles (VLP). Intranasal immunization of mice with this LAH-HBc VLP plus cholera toxin B subunit with 0.2% of cholera toxin (CTB(*)) adjuvant could effectively elicit humoral and cellular immune responses and protect mice against a lethal challenge of homologous influenza viruses (A/Puerto Rico/8/1934 (PR8) (H1N1)). In addition, passage of the immune sera containing specific antibodies to naïve mice rendered them resistant against a lethal homologous challenge. Immunization with LAH-HBc VLP vaccine plus CTB(*) adjuvant could also fully protect mice against a lethal challenge of the 2009 pandemic H1N1 influenza virus or the avian H9N2 virus and could partially protect mice against a lethal challenge of the avian H5N1 influenza virus. This study demonstrated that the LAH-HBc VLP vaccine based on a conserved sequence of the HA trimmer stalk region is a promising candidate vaccine for developing a universal influenza vaccine against multiple influenza viruses infections. PMID:25767809

  14. Subtyping Clinical Specimens of Influenza A Virus by Use of a Simple Method To Amplify RNA Targets

    PubMed Central

    Wang, Jingjing; Tai, Warren; Angione, Stephanie L.; John, Amrita R.; Opal, Steven M.; Artenstein, Andrew W.

    2013-01-01

    This work presents the clinical application of a robust and unique approach for RNA amplification, called a simple method for amplifying RNA targets (SMART), for the detection and identification of subtypes of H1N1 pandemic, H1N1 seasonal, and H3N2 seasonal influenza virus. While all the existing amplification techniques rely on the diffusion of two molecules to complex RNA structures, the SMART achieves fast and efficient amplification via single-molecule diffusion. The SMART utilizes amplifiable single-stranded DNA (ssDNA) probes, which serve as reporter molecules for capturing specific viral RNA (vRNA) sequences and are subsequently separated on a microfluidic chip under zero-flow conditions. The probe amplification and detection are performed using an isothermal (41°C) amplification scheme via a modified version of nucleic acid sequence-based amplification (NASBA). In our study, 116 consecutive, deidentified, clinical nasopharyngeal swab samples were analyzed independently in a blinded fashion using the SMART, reverse transcription-PCR (RT-PCR), antigen (Ag) testing, and viral culture. The SMART was shown to have a limit of detection (LOD) of approximately 105 vRNA copies/ml, corresponding with a time-to-positivity (TTP) value of 70 min for real-time detection. The SMART correctly detected influenza virus in 98.3% of the samples with a subtyping accuracy of 95.7%. This work demonstrates that the SMART represents a highly accurate diagnostic platform for the detection and subtyping of influenza virus in clinical specimens and offers significant advantages over the current commercially available diagnostic tools. PMID:23903546

  15. Optimal designs of an HA-based DNA vaccine against H7 subtype influenza viruses

    PubMed Central

    Zhang, Lu; Jia, Na; Li, Jun; Han, Yaping; Cao, Wuchun; Wang, Shixia; Huang, Zuhu; Lu, Shan

    2014-01-01

    The outbreak of a novel H7N9 influenza virus in 2013 has raised serious concerns for the potential of another avian-source pandemic influenza. Effective vaccines against H7N9 virus are important in the prevention and control of any major outbreak. Novel vaccination technologies are useful additions to existing approaches. In the current report, DNA vaccine studies were conducted to identify the optimal design of an H7 HA antigen using the HA gene from a previously reported H7N7 virus that is lethal in humans as the model antigen. New Zealand White rabbits were immunized with DNA vaccines expressing 1 of 3 forms of H7 HA antigen inserts encoding the HA gene from the same H7N7 virus. High-level H7 HA-specific IgG was detected by ELISA, and functional antibodies were confirmed by hemagglutination inhibition assay and pseudotyped virus-based neutralization assay against viruses expressing HA antigens from either the previous H7N7 virus or the novel H7N9 virus. HA antigen design under the tissue plasminogen activator leader (tPA) was the most immunogenic. The data presented in the current report confirm the immunogenicity of the H7 HA antigen and provide useful guidance to prepare for an optimized H7 HA DNA vaccine to help to control the emerging H7N9 virus if and when it is needed. PMID:25424804

  16. Antibodies to H5 subtype avian influenza virus and Japanese encephalitis virus in northern pintails (Anas acuta) sampled in Japan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blood samples from 105 northern pintails (Anas acuta) captured on Hokkaido, Japan were tested for antibodies to avian influenza virus (AIV), Japanese encephalitis virus (JEV) and West Nile virus (WNV) to assess possible involvement of this species in the transmission and spread of economically impor...

  17. Pathobiology of avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus causes serious disease in a wide variety of birds and mammals. Its natural hosts are wild aquatic birds, in which most infections are unapparent. Avian Influenza (AI) viruses are classified into 16 hemagglutinin (H1-16) and nine neuraminidase (N1-9) subtypes. Each virus has on...

  18. Development of a Reverse Transcription Loop-Mediated Isothermal Amplification Method for the Rapid Detection of Subtype H7N9 Avian Influenza Virus

    PubMed Central

    Bao, Hongmei; Zhao, Yuhui; Wang, Yunhe; Xu, Xiaolong; Shi, Jianzhong; Zeng, Xianying; Wang, Xiurong; Chen, Hualan

    2014-01-01

    A novel influenza A (H7N9) virus has emerged in China. To rapidly detect this virus from clinical samples, we developed a reverse transcription loop-mediated isothermal amplification (RT-LAMP) method for the detection of the H7N9 virus. The minimum detection limit of the RT-LAMP assay was 0.01 PFU H7N9 virus, making this method 100-fold more sensitive to the detection of the H7N9 virus than conventional RT-PCR. The H7N9 virus RT-LAMP assays can efficiently detect different sources of H7N9 influenza virus RNA (from chickens, pigeons, the environment, and humans). No cross-reactive amplification with the RNA of other subtype influenza viruses or of other avian respiratory viruses was observed. The assays can effectively detect H7N9 influenza virus RNA in drinking water, soil, cloacal swab, and tracheal swab samples that were collected from live poultry markets, as well as human H7N9 virus, in less than 30 min. These results suggest that the H7N9 virus RT-LAMP assays were efficient, practical, and rapid diagnostic methods for the epidemiological surveillance and diagnosis of influenza A (H7N9) virus from different resource samples. PMID:24689044

  19. A multiplex RT-PCR assay for detection and differentiation of avian H3, H5, and H9 subtype influenza viruses and Newcastle disease viruses.

    PubMed

    Tang, Qingdong; Wang, Jinliang; Bao, Jingnan; Sun, Honglei; Sun, Yipeng; Liu, Jinhua; Pu, Juan

    2012-05-01

    Avian influenza viruses (AIVs) and Newcastle disease viruses (NDVs) co-circulate in the poultry population in China. These viruses cause repeated disease outbreaks that exhibit similar clinical symptoms and epidemiological patterns. H5 and H9 influenza viruses are the major pathogens infecting poultry stocks. Recently, H3 AIV (one of the main subtypes in waterfowl) has become endemic in chickens. A multiplex reverse-transcriptase polymerase chain reaction (mRT-PCR) assay was designed for simultaneous detection and differentiation of avian H3, H5, H9 subtype AIVs and NDVs. Four primer sets were evaluated, three of which specifically targeted the hemagglutinin genes of H3, H5 and H9 AIVs, while the other targeted the NDV fusion gene. The sensitivity and specificity of the mRT-PCR assay was determined. The assay detected the major clades or genotypes of all of the reference AIVs and NDVs currently circulating in China. In addition, the mRT-PCR results obtained from screening 380 clinical swabs and 12 experimental tracheal samples were consistent with those obtained using conventional virus isolation methods. The mRT-PCR assay was established successfully for the detection and differentiation of avian H3, H5, and H9 subtype AIVs and NDVs. The method should, therefore, provide a valuable diagnostic tool for these infections. PMID:22387341

  20. In silico modification of oseltamivir as neuraminidase inhibitor of influenza A virus subtype H1N1

    PubMed Central

    Tambunan, Usman Sumo Friend; Rachmania, Rizky Archintya; Parikesit, Arli Aditya

    2015-01-01

    Abstract This research focused on the modification of the functional groups of oseltamivir as neuraminidase inhibitor against influenza A virus subtype H1N1. Interactions of three of the best ligands were evaluated in the hydrated state using molecular dynamics simulation at two different temperatures. The docking result showed that AD3BF2D ligand (N-[(1S,6R)-5-amino-5-{[(2R,3S,4S)-3,4-dihydroxy-4-(hydroxymethyl) tetrahydrofuran-2-yl]oxy}-4-formylcyclohex-3-en-1-yl]acetamide-3-(1-ethylpropoxy)-1-cyclohexene-1-carboxylate) had better binding energy values than standard oseltamivir. AD3BF2D had several interactions, including hydrogen bonds, with the residues in the catalytic site of neuraminidase as identified by molecular dynamics simulation. The results showed that AD3BF2D ligand can be used as a good candidate for neuraminidase inhibitor to cope with influenza A virus subtype H1N1. PMID:25859271

  1. Isolation and characterization of highly pathogenic avian influenza virus subtype H5N1 from donkeys

    PubMed Central

    2010-01-01

    Background The highly pathogenic H5N1 is a major avian pathogen that crosses species barriers and seriously affects humans as well as some mammals. It mutates in an intensified manner and is considered a potential candidate for the possible next pandemic with all the catastrophic consequences. Methods Nasal swabs were collected from donkeys suffered from respiratory distress. The virus was isolated from the pooled nasal swabs in specific pathogen free embryonated chicken eggs (SPF-ECE). Reverse transcriptase polymerase chain reaction (RT-PCR) and sequencing of both haemagglutingin and neuraminidase were performed. H5 seroconversion was screened using haemagglutination inhibition (HI) assay on 105 donkey serum samples. Results We demonstrated that H5N1 jumped from poultry to another mammalian host; donkeys. Phylogenetic analysis showed that the virus clustered within the lineage of H5N1 from Egypt, closely related to 2009 isolates. It harboured few genetic changes compared to the closely related viruses from avian and humans. The neuraminidase lacks oseltamivir resistant mutations. Interestingly, HI screening for antibodies to H5 haemagglutinins in donkeys revealed high exposure rate. Conclusions These findings extend the host range of the H5N1 influenza virus, possess implications for influenza virus epidemiology and highlight the need for the systematic surveillance of H5N1 in animals in the vicinity of backyard poultry units especially in endemic areas. PMID:20398268

  2. An enzyme-linked immunosorbent assay for detection of avian influenza virus subtypes H5 and H7 antibodies

    PubMed Central

    2013-01-01

    Background Avian influenza virus (AIV) subtypes H5 and H7 attracts particular attention because of the risk of their potential pathogenicity in poultry. The haemagglutination inhibition (HI) test is widely used as subtype specific test for serological diagnostics despite the laborious nature of this method. However, enzyme-linked immunosorbent assays (ELISAs) are being explored as an alternative test method. H5 and H7 specific monoclonal antibodies were experimentally raised and used in the development of inhibition ELISAs for detection of serological response specifically directed against AIV subtypes H5 and H7. The ELISAs were evaluated with polyclonal chicken anti-AIV antibodies against AIV subtypes: H1N2, H5N2, H5N7, H7N1, H7N7, H9N9, H10N4 and H16N3. Results Both the H5 and H7 ELISA proved to have a high sensitivity and specificity and the ELISAs detected H5 and H7 antibodies earlier during experimental infection than the HI test did. The reproducibility of the ELISA’s performed at different times was high with Pearson correlation coefficients of 0.96-0.98. Conclusions The ELISAs are a potential alternative to the HI test for screening of large amounts of avian sera, although only experimental sera were tested in this study. PMID:24256721

  3. Receptor mimicry by antibody F045-092 facilitates universal binding to the H3 subtype of influenza virus

    PubMed Central

    Lee, Peter S.; Ohshima, Nobuko; Stanfield, Robyn L.; Yu, Wenli; Iba, Yoshitaka; Okuno, Yoshinobu; Kurosawa, Yoshikazu; Wilson, Ian A.

    2015-01-01

    Influenza viruses present a significant health challenge each year, as in the H3N2 epidemic of 2012-2013. Here, we describe an antibody, F045-092, that possesses broadly neutralizing activity against the entire H3 subtype and accommodates the natural variation and additional glycosylation in all strains tested from 1963 to 2011. Crystal structures of F045-092 in complex with HAs from 1975 and 2011 H3N2 viruses reveal the structural basis for its neutralization breadth through insertion of its 23-residue HCDR3 into the receptor-binding site that involves striking receptor mimicry. F045-092 extends its recognition to divergent subtypes, including H1, H2, and H13, using the enhanced avidity of its IgG to overcome lower affinity Fab binding, as observed with other receptor-binding site antibodies. This unprecedented level of antibody cross-reactivity against the H3 subtype can potentially inform on development of a pan-H3 vaccine or small molecule therapeutics. PMID:24717798

  4. Receptor mimicry by antibody F045–092 facilitates universal binding to the H3 subtype of influenza virus

    SciTech Connect

    Lee, Peter S.; Ohshima, Nobuko; Stanfield, Robyn L.; Yu, Wenli; Iba, Yoshitaka; Okuno, Yoshinobu; Kurosawa, Yoshikazu; Wilson, Ian A.

    2014-04-10

    Influenza viruses present a significant health challenge each year, as in the H3N2 epidemic of 2012–2013. Here we describe an antibody, F045–092, that possesses broadly neutralizing activity against the entire H3 subtype and accommodates the natural variation and additional glycosylation in all strains tested from 1963 to 2011. Crystal structures of F045–092 in complex with HAs from 1975 and 2011 H3N2 viruses reveal the structural basis for its neutralization breadth through insertion of its 23-residue HCDR3 into the receptor-binding site that involves striking receptor mimicry. F045–092 extends its recognition to divergent subtypes, including H1, H2 and H13, using the enhanced avidity of its IgG to overcome lower-affinity Fab binding, as observed with other antibodies that target the receptor-binding site. This unprecedented level of antibody cross-reactivity against the H3 subtype can potentially inform on development of a pan-H3 vaccine or small-molecule therapeutics.

  5. Genome sequence of a novel H14N7 subtype influenza A virus isolated from a blue-winged teal (Anas discors) harvested in Texas, USA

    USGS Publications Warehouse

    Ramey, Andy M.; Reeves, Andrew; Poulson, Rebecca L.; Carter, Deborah L.; Davis-Fields, Nicholas; Stallknecht, David E.

    2016-01-01

    We report here the complete genome sequence of a novel H14N7 subtype influenza A virus (IAV) isolated from a blue-winged teal (Anas discors) harvested in Texas, USA. The genomic characteristics of this IAV strain with a previously undetected subtype combination suggest recent viral evolution within the New World wild-bird IAV reservoir.                   

  6. Protection of chickens to antigenically variant avian influenza virus challenge after immunization with two antigenically unrelated strains of the same subtype

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The antigenic diversity of avian influenza virus (AIV) within a subtype has been well established and is believed to be driven by the selection of immunologic escape mutants. In regions where vaccination against AIV has been implemented for prolonged periods (e.g. Vietnam and Egypt), vaccines which...

  7. Optical fiber sensor based on surface plasmon resonance for rapid detection of avian influenza virus subtype H6: Initial studies.

    PubMed

    Zhao, Xihong; Tsao, Yu-Chia; Lee, Fu-Jung; Tsai, Woo-Hu; Wang, Ching-Ho; Chuang, Tsung-Liang; Wu, Mu-Shiang; Lin, Chii-Wann

    2016-07-01

    A side-polished fiber optic surface plasmon resonance (SPR) sensor was fabricated to expose the core surface and then deposited with a 40nm thin gold film for the near surface sensing of effective refractive index changes with surface concentration or thickness of captured avian influenza virus subtype H6. The detection surface of the SPR optical fiber sensor was prepared through the plasma modification method for binding a self-assembled monolayer of isopropanol chemically on the gold surface of the optical fiber. Subsequently, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide/N-hydroxysuccinimide was activated to enable EB2-B3 monoclonal antibodies to capture A/chicken/Taiwan/2838V/00 (H6N1) through a flow injection system. The detection limit of the fabricated optical fiber sensor for A/chicken/Taiwan/2838V/00 was 5.14×10(5) EID50/0.1mL, and the response time was 10min on average. Moreover, the fiber optic sensor has the advantages of a compact size and low cost, thus rendering it suitable for online and remote sensing. The results indicated that the optical fiber sensor can be used for epidemiological surveillance and diagnosing of avian influenza subtype H6 rapidly. PMID:26996538

  8. Evidence for genetic variation of Eurasian avian influenza viruses of subtype H15: the first report of an H15N7 virus.

    PubMed

    Muzyka, Denys; Pantin-Jackwood, Mary; Starick, Elke; Fereidouni, Sasan

    2016-03-01

    Since the first detection of H15 avian influenza viruses (AIVs) in Australia in 1979, only seven H15 strains have been reported. A new H15 AIV was detected in Ukraine in 2010, carrying the unique HA-NA subtype combination H15N7. This virus replicated efficiently in chicken eggs, and antisera against it reacted strongly with the homologous antigen, but with lower titers when using the reference Australian antigen. The amino acid motifs of the HA cleavage site and receptor-binding site were different from those in the Australian viruses. The new virus, together with an H15 virus from Siberia from 2008, constitutes a new clade of H15 AIV isolates. PMID:26650037

  9. Construction and Immunogenicity Evaluation of Recombinant Influenza A Viruses Containing Chimeric Hemagglutinin Genes Derived from Genetically Divergent Influenza A H1N1 Subtype Viruses

    PubMed Central

    McCormick, Kara; Jiang, Zhiyong; Zhu, Longchao; Lawson, Steven R.; Langenhorst, Robert; Ransburgh, Russell; Brunick, Colin; Tracy, Miranda C.; Hurtig, Heather R.; Mabee, Leah M.; Mingo, Mark; Li, Yanhua; Webby, Richard J.

    2015-01-01

    Background and Objectives Influenza A viruses cause highly contagious diseases in a variety of hosts, including humans and pigs. To develop a vaccine that can be broadly effective against genetically divergent strains of the virus, in this study we employed molecular breeding (DNA shuffling) technology to create a panel of chimeric HA genes. Methods and Results Each chimeric HA gene contained genetic elements from parental swine influenza A viruses that had a history of zoonotic transmission, and also from a 2009 pandemic virus. Each parental virus represents a major phylogenetic clade of influenza A H1N1 viruses. Nine shuffled HA constructs were initially screened for immunogenicity in mice by DNA immunization, and one chimeric HA (HA-129) was expressed on both a A/Puerto Rico/8/34 backbone with mutations associated with a live, attenuated phenotype (PR8LAIV-129) and a A/swine/Texas/4199-2/98 backbone (TX98-129). When delivered to mice, the PR8LAIV-129 induced antibodies against all four parental viruses, which was similar to the breadth of immunity observed when HA-129 was delivered as a DNA vaccine. This chimeric HA was then tested as a candidate vaccine in a nursery pig model, using inactivated TX98-129 virus as the backbone. The results demonstrate that pigs immunized with HA-129 developed antibodies against all four parental viruses, as well as additional primary swine H1N1 influenza virus field isolates. Conclusion This study established a platform for creating novel genes of influenza viruses using a molecular breeding approach, which will have important applications toward future development of broadly protective influenza virus vaccines. PMID:26061265

  10. Human microRNAs profiling in response to influenza A viruses (subtypes pH1N1, H3N2, and H5N1).

    PubMed

    Makkoch, Jarika; Poomipak, Witthaya; Saengchoowong, Suthat; Khongnomnan, Kritsada; Praianantathavorn, Kesmanee; Jinato, Thananya; Poovorawan, Yong; Payungporn, Sunchai

    2016-02-01

    MicroRNAs (miRNAs) play an important role in regulation of gene silencing and are involved in many cellular processes including inhibition of infected viral replication. This study investigated cellular miRNA expression profiles operating in response to influenza virus in early stage of infection which might be useful for understanding and control of viral infection. A549 cells were infected with different subtypes of influenza virus (pH1N1, H3N2 and H5N1). After 24 h post-infection, miRNAs were extracted and then used for DNA library construction. All DNA libraries with different indexes were pooled together with equal concentration, followed by high-throughput sequencing based on MiSeq platform. The miRNAs were identified and counted from sequencing data by using MiSeq reporter software. The miRNAs expressions were classified into up and downregulated miRNAs compared to those found in non-infected cells. Mostly, each subtype of influenza A virus triggered the upregulated responses in miRNA expression profiles. Hsa-miR-101, hsa-miR-193b, hsa-miR-23b, and hsa-miR-30e* were upregulated when infected with all three subtypes of influenza A virus. Target prediction results showed that virus infection can trigger genes in cellular process, metabolic process, developmental process and biological regulation. This study provided some insights into the cellular miRNA profiling in response to various subtypes of influenza A viruses in circulation and which have caused outbreaks in human population. The regulated miRNAs might be involved in virus-host interaction or host defense mechanism, which should be investigated for effective antiviral therapeutic interventions. PMID:26518627

  11. Receptor specificity of subtype H1 influenza A viruses isolated from swine and humans in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The evolution of receptor specificity of classical swine influenza viruses leading to the 2009 H1N1 pandemic virus was analyzed in glycan microarrays. Classical influenza viruses from the alpha, beta, and gamma antigenic clusters isolated between 1945 and 2009 revealed a binding profile very simila...

  12. Genetic characterization of influenza A virus subtypes H1N3 and H1N9 isolated from free-grazing ducks in Thailand.

    PubMed

    Chaiyawong, Supassama; Boonyapisitsopa, Supanat; Jairak, Waleemas; Nonthabenjawan, Nutthawan; Tangwangvivat, Ratanaporn; Bunpapong, Napawan; Amonsin, Alongkorn

    2016-10-01

    Influenza A virus (IAV) subtype H1 has been reported to infect birds, pigs and humans. In this study, we characterized IAVs subtype H1N3 and H1N9 isolated from free-grazing ducks in Thailand. Phylogenetic analysis showed that Thai IAV-H1 isolates cluster with avian Eurasian-lineage but not pandemic H1N1 viruses. Analysis of the viruses indicated low-pathogenic avian influenza (LPAI) characteristics. This study is the first report of avian H1N3 and H1N9 in Thailand. Although Thai IAV-H1 viruses do not pose a risk of a pandemic, routine surveillance and genetic monitoring of IAVs should be conducted. PMID:27383209

  13. [Isolation and Identification of a Quail-origin H9N2 Subtype of The Influenza Virus and Its Biologic Characterization].

    PubMed

    Yu, Yang; Si, Weiying; Yuan, Zhuangchuan; Yan, Yan; Zhou, Jiyong

    2016-01-01

    A quail-origin subtype of the influenza virus was isolated from a human-infecting H7N9 subtype of the avian influenza virus found in a live poultry market and was given the name A/Quail/Hangzhou/1/ 2013 (H9N2). We analyzed the whole genome of this virus and its biologic characteristics. Sequence analyses suggested that the: HA and NS genes belonged to a CK/BJ/1/94-like lineage; NA, NP, PA and PB1 genes belonged to a SH/F/98-like lineage; M and PB2 genes belonged to a G1-like lineage. Analyses of key amino acids showed that the cleavage site in HA protein was PSRSSR ↓ GL, and that the HA protein had a human receptor-binding site with Leu226. Deletion of amino acids 69 - 73 was detected in the stalk of NA protein, the M2 protein had an Asn31 mutation, and the NS1 protein had two mutations at Ser42, Ala149. The intravenous pathogenicity of this virus was 0.36. A study in chickens suggested that all inoculated birds shed the virus from the trachea and cloaca on the third day post-infection (p. i. ) until 11 days. All chickens that had direct contact shed the virus on the second day p. i. until 8 days. Results of virus reisolation suggested that lung and tracheal tissues could shed the virus in 5 days, whereas the other organs could shed the virus in 3 days. These results suggest that this virus strain is H9N2 subtype LPAIV, whose lineage is prevalent in mainland China. This research provides evidence on how to monitor and prevent the H9N2 subtype of the avian influenza virus. PMID:27295886

  14. Structure and Receptor Binding Preferences of Recombinant Hemagglutinins from Avian and Human H6 and H10 Influenza A Virus Subtypes

    PubMed Central

    Yang, Hua; Carney, Paul J.; Chang, Jessie C.; Villanueva, Julie M.

    2015-01-01

    ABSTRACT During 2013, three new avian influenza A virus subtypes, A(H7N9), A(H6N1), and A(H10N8), resulted in human infections. While the A(H7N9) virus resulted in a significant epidemic in China across 19 provinces and municipalities, both A(H6N1) and A(H10N8) viruses resulted in only a few human infections. This study focuses on the major surface glycoprotein hemagglutinins from both of these novel human viruses. The detailed structural and glycan microarray analyses presented here highlight the idea that both A(H6N1) and A(H10N8) virus hemagglutinins retain a strong avian receptor binding preference and thus currently pose a low risk for sustained human infections. IMPORTANCE Human infections with zoonotic influenza virus subtypes continue to be a great public health concern. We report detailed structural analysis and glycan microarray data for recombinant hemagglutinins from A(H6N1) and A(H10N8) viruses, isolated from human infections in 2013, and compare them with hemagglutinins of avian origin. This is the first structural report of an H6 hemagglutinin, and our results should further the understanding of these viruses and provide useful information to aid in the continuous surveillance of these zoonotic influenza viruses. PMID:25673707

  15. Naturally occurring Influenza A virus subtype H1N2 infection in a Midwest United States mink (Mustela vison) ranch.

    PubMed

    Yoon, Kyoung-Jin; Schwartz, Kent; Sun, Dong; Zhang, Jianqiang; Hildebrandt, Hugh

    2012-03-01

    Influenza A virus (FLUAV) causes acute respiratory disease in humans and a variety of animal species. The virus tends to remain within the species of origin; nonetheless, naturally occurring cross-species transmission of FLUAV has been periodically documented. Multiple cross-species transmissions of FLUAV have been reported from companion animals and captive wild animals, neither of which is historically considered as natural hosts of FLUAV. In the fall of 2010, mink (Mustela vison) inhabiting a 15,000-head mink farm in the Midwest United States experienced persistent severe respiratory distress and nose and/or mouth bleeding. Mink losses averaged approximately 10 animals per day. Six dead mink at 6 months of age were submitted to the Iowa State University Veterinary Diagnostic Laboratory for diagnostic investigation. Gross and microscopic examinations revealed that all 6 mink had hemorrhagic bronchointerstitial pneumonia. Hemolytic Escherichia coli was isolated from lungs, probably accounting for hemorrhagic pneumonia. All animals tested negative for Canine distemper virus and Aleutian mink disease virus. Interestingly, FLUAV of H1N2 subtype, which contained the matrix gene of swine lineage, was detected in the lungs. Serological follow-up on mink that remained in the ranch until pelting also confirmed that the ranch had been exposed to FLUAV of H1 subtype (δ clade). The case study suggests that FLUAV should be included in the differential diagnosis when mink experience epidemics of respiratory disease. Since the source of FLUAV appeared to be uncooked turkey meat, feeding animals fully cooked ration should be considered as a preventive measure. PMID:22362526

  16. Experimental infection of mallard ducks with different subtype H5 and H7 highly pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza viruses (HPAIV’s) remain a threat to poultry worldwide. Avian influenza viruses, including HPAIV, are usually non-pathogenic for ducks and other wild aquatic birds, with the exception of some Asian lineage H5N1 HPAIVs which can cause severe disease in ducks. With ...

  17. Replication and transmission of mammalian-adapted H9 subtype influenza virus in pigs and quail

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A is a major pathogen of birds, swine, and humans. Strains can jump from one species to another in a process that often requires genetic mutation and genome reassortment and results in outbreaks and, potentially, pandemics. H9N2 avian influenza is one of the most predominant influenza subt...

  18. Antibodies to H5 subtype avian influenza virus and Japanese encephalitis virus in northern pintails (Anas acuta) sampled in Japan

    USGS Publications Warehouse

    Ramey, Andy M.; Spackman, Erica; Yeh, Jung-Yong; Fujita, Go; Konishi, Kan; Reed, John A.; Wilcox, Benjamin R.; Brown, Justin D.; Stallknecht, David E.

    2013-01-01

    Blood samples from 105 northern pintails (Anas acuta) captured on Hokkaido, Japan were tested for antibodies to avian influenza virus (AIV), Japanese encephalitis virus (JEV), and West Nile virus (WNV) to assess possible involvement of this species in the spread of economically important and potentially zoonotic pathogens. Antibodies to AIV were detected in 64 of 105 samples (61%). Of the 64 positives, 95% and 81% inhibited agglutination of two different H5 AIV antigens (H5N1 and H5N9), respectively. Antibodies to JEV and WNV were detected in five (5%) and none of the samples, respectively. Results provide evidence for prior exposure of migrating northern pintails to H5 AIV which couldhave implications for viral shedding and disease occurrence. Results also provide evidence for limited involvement of this species in the transmission and spread of flaviviruses during spring migration.

  19. Design of Multiplexed Detection Assays for Identification of Avian Influenza A Virus Subtypes Pathogenic to Humans by SmartCycler Real-Time Reverse Transcription-PCR ▿

    PubMed Central

    Wang, Wei; Ren, Peijun; Mardi, Sek; Hou, Lili; Tsai, Cheguo; Chan, Kwok Hung; Cheng, Peter; Sheng, Jun; Buchy, Philippe; Sun, Bing; Toyoda, Tetsuya; Lim, Wilina; Peiris, J. S. Malik; Zhou, Paul; Deubel, Vincent

    2009-01-01

    Influenza A virus (IAV) epidemics are the result of human-to-human or poultry-to-human transmission. Tracking seasonal outbreaks of IAV and other avian influenza virus (AIV) subtypes that can infect humans, aquatic and migratory birds, poultry, and pigs is essential for epidemiological surveillance and outbreak alerts. In this study, we performed four real-time reverse transcription-PCR (rRT-PCR) assays for identification of the IAV M and hemagglutinin (HA) genes from six known AIVs infecting pigs, birds, and humans. IAV M1 gene-positive samples tested by single-step rRT-PCR and a fluorogenic Sybr green I detection system were further processed for H5 subtype identification by using two-primer-set multiplex and Sybr green I rRT-PCR assays. H5 subtype-negative samples were then tested with either a TaqMan assay for subtypes H1 and H3 or a TaqMan assay for subtypes H2, H7, and H9 and a beacon multiplex rRT-PCR identification assay. The four-tube strategy was able to detect 10 RNA copies of the HA genes of subtypes H1, H2, H3, H5, and H7 and 100 RNA copies of the HA gene of subtype H9. At least six H5 clades of H5N1 viruses isolated in Southeast Asia and China were detected by that test. Using rRT-PCR assays for the M1 and HA genes in 202 nasopharyngeal swab specimens from children with acute respiratory infections, we identified a total of 39 samples positive for the IAV M1 gene and subtypes H1 and H3. When performed with a portable SmartCycler instrument, the assays offer an efficient, flexible, and reliable platform for investigations of IAV and AIV in remote hospitals and in the field. PMID:18971359

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. Single assay for simultaneous detection and differential identification of human and avian influenza virus types, subtypes, and emergent variants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rapid and accurate detection, identification and genetic characterization are essential for effective surveillance and epidemiological tracking of influenza viruses. This report describes applications of a resequencing pathogen microarray (RPM) assay that is capable of simultaneous sequencing of su...

  2. A sero-survey of subtype H3 influenza A virus infection in dogs and cats in Japan.

    PubMed

    Said, Awlad Wadair Ali; Usui, Tatsufumi; Shinya, Kyoko; Ono, Etsuro; Ito, Toshihiro; Hikasa, Yoshiaki; Matsuu, Aya; Takeuchi, Takashi; Sugiyama, Akihiko; Nishii, Naohito; Yamaguchi, Tsuyoshi

    2011-04-01

    A sero-epidemiological survey of human and equine H3 influenza A virus infections in dogs and cats using the hemagglutination inhibition (HI) and neuraminidase inhibition (NI) tests was conducted. Serum samples were collected from 582 dogs and 237 cats in Japan during the periods 2002-2008 and 1997-2008, respectively. Although no HI antibodies against equine H3 virus were detected, 9 (3.8%) from cats and 12 (2.1%) from dogs were HI-positive against human H3 virus. Only one serum each from dogs and cats was NI-positive against N2 virus. These findings suggest that although equine H3 influenza virus infections have not been prevalent in companion animals, human H3N2 influenza A virus infections have occurred in dogs and cats in recent years in Japan. PMID:21150133

  3. Disease Dynamics and Bird Migration—Linking Mallards Anas platyrhynchos and Subtype Diversity of the Influenza A Virus in Time and Space

    PubMed Central

    Gunnarsson, Gunnar; Latorre-Margalef, Neus; Hobson, Keith A.; Van Wilgenburg, Steven L.; Elmberg, Johan; Olsen, Björn; Fouchier, Ron A. M.; Waldenström, Jonas

    2012-01-01

    The mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and transmitted to conspecifics during subsequent staging during migration, and so a better understanding of the natal origin of staging ducks is vital to deciphering the dynamics of viral movement pathways. Ottenby is an important stopover site in southeast Sweden almost halfway downstream in the major Northwest European flyway, and is used by millions of waterfowl each year. Here, mallards were captured and sampled for influenza A virus infection, and positive samples were subtyped in order to study possible links to the natal area, which were determined by a novel approach combining banding recovery data and isotopic measurements (δ2H) of feathers grown on breeding grounds. Geographic assignments showed that the core natal areas of studied mallards were in Estonia, southern and central Finland, and northwestern Russia. This study demonstrates a clear temporal succession of latitudes of natal origin during the course of autumn migration. We also demonstrate a corresponding and concomitant shift in virus subtypes. Acknowledging that these two different patterns were based in part upon different data, a likely interpretation worth further testing is that the early arriving birds with more proximate origins have different influenza A subtypes than the more distantly originating late autumn birds. If true, this knowledge would allow novel insight into the origins and transmission of the influenza A virus among migratory hosts previously unavailable through conventional approaches. PMID:22536424

  4. Influenza Virus Infection of Marine Mammals.

    PubMed

    Fereidouni, Sasan; Munoz, Olga; Von Dobschuetz, Sophie; De Nardi, Marco

    2016-03-01

    Interspecies transmission may play a key role in the evolution and ecology of influenza A viruses. The importance of marine mammals as hosts or carriers of potential zoonotic pathogens such as highly pathogenic H5 and H7 influenza viruses is not well understood. The fact that influenza viruses are some of the few zoonotic pathogens known to have caused infection in marine mammals, evidence for direct transmission of influenza A virus H7N7 subtype from seals to man, transmission of pandemic H1N1 influenza viruses to seals and also limited evidence for long-term persistence of influenza B viruses in seal populations without significant genetic change, makes monitoring of influenza viruses in marine mammal populations worth being performed. In addition, such monitoring studies could be a great tool to better understand the ecology of influenza viruses in nature. PMID:25231137

  5. Isolation and genetic characterization of novel reassortant H6N6 subtype avian influenza viruses isolated from chickens in eastern China.

    PubMed

    Wu, Haibo; Lu, Rufeng; Peng, Xiuming; Peng, Xiaorong; Cheng, Linfang; Jin, Changzhong; Lu, Xiangyun; Xie, Tiansheng; Yao, Hangping; Wu, Nanping

    2016-07-01

    H6 subtype avian influenza viruses (AIVs) possess the ability to cross the species barrier to infect mammals and pose a threat to human health. From June 2014 to July 2015, 12 H6N6 AIVs were isolated from chickens in live-poultry markets in Zhejiang Province, Eastern China. Phylogenetic analysis showed that these isolates received their genes from H6 and H9N2 subtype AIVs of poultry in China. These novel reassortant viruses showed moderate pathogenicity in mice and were able to replicate in mice without prior adaptation. Considering that novel reassorted H6N6 viruses were isolated from chickens in this study, it is possible that these chickens play an important role in the generation of novel reassorted H6N6 AIVs, and these results emphasize the need for continued surveillance of the H6N6 AIVs circulating in poultry. PMID:27101069

  6. Transmission of Avian Influenza A Viruses Between Animals and People

    MedlinePlus

    ... many different animals, including ducks, chickens, pigs, whales, horses, and seals. However, certain subtypes of influenza A ... pigs, and H7N7 and H3N8 virus infections of horses. Influenza A viruses that typically infect and transmit ...

  7. Live vaccination with an H5-hemagglutinin-expressing infectious laryngotracheitis virus recombinant protects chickens against different highly pathogenic avian influenza viruses of the H5 subtype.

    PubMed

    Pavlova, Sophia P; Veits, Jutta; Mettenleiter, Thomas C; Fuchs, Walter

    2009-08-13

    Recently, we described an infectious laryngotracheitis virus (ILTV, gallid herpesvirus 1) recombinant, which had been attenuated by deletion of the viral dUTPase gene UL50, and abundantly expressed the hemagglutinin (HA) gene of a H5N1 type highly pathogenic avian influenza virus (HPAIV) of Vietnamese origin. In the present study, efficacy of this vectored vaccine (ILTV-DeltaUL50IH5V) against different H5 HPAIV was evaluated in 6-week-old chickens. After a single ocular immunization all animals developed HA-specific antibodies, and were protected against lethal infection not only with the homologous HPAIV isolate A/duck/Vietnam/TG24-01/2005 (H5N1, clade 1, hemagglutinin amino acid sequence identity 100%), but also with heterologous HPAIV A/swan/Germany/R65/2006 (H5N1, clade 2.2, identity 96.1%) or HPAIV A/chicken/Italy/8/98 (H5N2, identity 93.8%). No symptoms of disease were observed after challenge with the H5N1 viruses, and only 20% of H5N2 challenged animals developed minimal clinical signs. Real-time RT-PCR analyses of oropharyngeal swabs revealed limited challenge virus replication, but the almost complete absence of HPAIV RNA from cloacal swabs indicated that no generalized infections occurred. Thus, unlike several previous vectors, ILTV-DeltaUL50IH5V was able to protect chickens against different HPAIV isolates of the H5 subtype. Vaccination with HA-expressing ILTV also allowed differentiation of immunized from AIV-infected animals by serological tests for antibodies against influenza virus nucleoprotein. PMID:19573638

  8. [Construction and experimental immunity of recombinant replication-competent canine adenovirus type 2 expressing hemagglutinin gene of H5N1 subtype tiger influenza virus].

    PubMed

    Gao, Yu-Wei; Xia, Xian-Zhu; Wang, Li-Gang; Liu, Dan; Huang, Geng

    2006-04-01

    H5N1 highly pathogenic avian influenza virus was highly pathogenic and sometimes even fatal for tigers and cats. To develop a new type of vaccine for Felidae influenza prevention, recombinant replication-competent canine adenovirus Type 2 expressing hemagglutinin gene of H5N1 subtype tiger influenza virus was constructed. A/tiger/Harbin/01/2003 (HSN1) HA gene was cloned into PVAX1. The HA expression cassette which included CMV and HA and PolyA was ligated into the E3 deletion region of pVAXdeltaE. The recombinant plasmid was named pdeltaEHA. The pdelta EHA and the pPoly2-CAV2 were digested with Nru I /Sal I, respectively. The purified Nru I/Sal I DNA fragment containing the HA expression cassette was cloned into pPoly2-CAV2 to generate the recombinant plasmid pCAV-2/HA. The recombinant genome was released from pCAV-2/HA, and was transfected into MDCK cells by Lipofectamine. The recombinant virus named CAV2/HA was gained. Anti-H5N1 influenza virus HI antibody (1:8 - 1:16) was detected in the cat immunized with CAV-2/HA. PMID:16736595

  9. [Influenza virus].

    PubMed

    Juozapaitis, Mindaugas; Antoniukas, Linas

    2007-01-01

    Every year, especially during the cold season, many people catch an acute respiratory disease, namely flu. It is easy to catch this disease; therefore, it spreads very rapidly and often becomes an epidemic or a global pandemic. Airway inflammation and other body ailments, which form in a very short period, torment the patient several weeks. After that, the symptoms of the disease usually disappear as quickly as they emerged. The great epidemics of flu have rather unique characteristics; therefore, it is possible to identify descriptions of such epidemics in historic sources. Already in the 4th century bc, Hippocrates himself wrote about one of them. It is known now that flu epidemics emerge rather frequently, but there are no regular intervals between those events. The epidemics can differ in their consequences, but usually they cause an increased mortality of elderly people. The great flu epidemics of the last century took millions of human lives. In 1918-19, during "The Spanish" pandemic of flu, there were around 40-50 millions of deaths all over the world; "Pandemic of Asia" in 1957 took up to one million lives, etc. Influenza virus can cause various disorders of the respiratory system: from mild inflammations of upper airways to acute pneumonia that finally results in the patient's death. Scientist Richard E. Shope, who investigated swine flu in 1920, had a suspicion that the cause of this disease might be a virus. Already in 1933, scientists from the National Institute for Medical Research in London - Wilson Smith, Sir Christopher Andrewes, and Sir Patrick Laidlaw - for the first time isolated the virus, which caused human flu. Then scientific community started the exhaustive research of influenza virus, and the great interest in this virus and its unique features is still active even today. PMID:18182834

  10. Understanding of Drug-Target Interactions: A case Study in Influenza Virus A Subtype H5N1

    NASA Astrophysics Data System (ADS)

    Rungrotmongkol, Thanyada; Malaisree, Maturos; Decha, Panita; Laohpongspaisan, Chittima; Aruksakunwong, Ornjira; Intharathep, Pathumwadee; Pianwanit, Somsak; Sompornpisut, Pornthep; Parasuk, Vudhichai; Megnassan, Eugene; Frecer, Vladimir; Miertus, Stanislav; Hannongbua, Supot

    2007-12-01

    This study aims at gaining insight into molecular mechanisms of action of three drug targets of the life cycle of influenza virus A subtype H5N1, namely Hemagglutinin (H5), Neuraminidase (N1) and M2 ion channel (M2), using molecular mechanics and molecular dynamics techniques. In hemagglutinin, interest is focused on the high pathogenicity of the H5 due to the -RRRKK- insertion. MD simulations carried out for H5 in both high and low pathogenic forms (HPH5 and LPH5), aimed at understanding why HPH5 was experimentally observed to be 5-fold better cleaved by furin relative to the non-inserted sequence of LPH5. As the results, the cleavage loop of HPH5 was found to fit well and bind strongly into the catalytic site of human furin, serving as a conformation suitable for the proteolytic reaction. The second target, neuraminidase was studied by two different approaches. Firstly with MD simulations, rotation of the -NHAc and—OCHEt2 side chains of oseltamivir (OTV), leading directly to rearrangement of the catalytic cavity, was found to be a primary source of the lower susceptibility of OTV to neuraminidase subtype N1 than to N2 and N9. In addition, three inhibitiors, OTV, zanamivir (ZNV) and peramivir (PRV), complexed with neuraminidase subtype N1 were studied to understand the drug-target interactions. The structural properties, position and conformation of PRV and its side chains are uniformly preferential, i.e., its conformation fits very well with the N1 active site. At the N1 target, another approach, combinatorial chemistry, was used to design a library of new potent inhibitors, which well fit to the active site and the 150-loop residues of N1. Investigation was also extended to the M2 proton channel. Five different protonation states of the selectivity filter residue (His) where 0H, 1H, 2aH, 2dH and 4H represent the systems with none, mono-protonated, di-protonated at adjacent and opposite positions, and tetra-protonated, respectively, were taken into account both

  11. Influenza A virus recycling revisited.

    PubMed Central

    Dowdle, W. R.

    1999-01-01

    Current textbooks link influenza pandemics to influenza A virus subtypes H2 (1889-91), H3 (1990), H1 (1918-20), H2 (1957-58) and H3 (1968), a pattern suggesting subtype recycling in humans. Since H1 reappeared in 1977, whatever its origin, some workers feel that H2 is the next pandemic candidate. This report reviews the publications on which the concept of influenza A virus subtype recycling is based and concludes that the data are inconsistent with the purported sequence of events. The three influenza pandemics prior to 1957-58 were linked with subtypes through retrospective studies of sera from the elderly, or through seroarchaeology. The pandemic seroarchaeological model for subtype H1 has been validated by the recent recovery of swine virus RNA fragments from persons who died from influenza in 1918. Application of the model to pre-existing H3 antibody among the elderly links the H3 subtype to the pandemic of 1889-91, not that of 1900 as popularly quoted. Application of the model to pre-existing H2 antibody among the elderly fails to confirm that this subtype caused a pandemic in the late 1800's, a finding which is consistent with age-related excess mortality patterns during the pandemics of 1957 (H2) and 1968 (H3). H2 variants should be included in pandemic planning for a number of reasons, but not because of evidence of recycling. It is not known when the next pandemic will occur or which of the 15 (or more) haemagglutinin subtypes will be involved. Effective global surveillance remains the key to influenza preparedness. PMID:10593030

  12. 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. PMID:26473686

  13. Identification and genetic analysis of H3N8 subtype influenza viruses isolated from domestic pigeons in Central China.

    PubMed

    Zou, Zhong; Chen, Sunrui; Liu, Ziduo; Jin, Meilin

    2016-02-01

    A novel strain of H3N8 influenza virus was isolated from domestic pigeons during the avian influenza virus (AIV) surveillance in wet markets in Anhui, China, during 2013. The virus was characterized by whole-genome sequencing with subsequent genetic comparison and phylogenetic analysis. Phylogenetic analysis revealed that the NA gene of AIV mapped to the North American lineage, and the remaining seven genes belong to a Eurasian lineage. These findings indicated that this H3N8 virus is a novel nature reassortant virus. Comparison of the hemagglutinin amino acid sequences indicated 9 substitutions. One substitution caused the loss of a potential glycosylation site, and six substitutions were not previously observed in avian H3 isolates. Q226 and T228 at the receptor binding sites suggested that Anhui-08 preferentially binds to a-2,3-linked sialic acid receptors, and the cleavage site sequence showed a low pathogenic feature. Animal experiments further confirmed that A/pigeon/Anhui/08/2013 (H3N8) is low or in pigeons. The results improve our understanding of these viruses as they evolve and also provide important information to aid ongoing risk assessment analyses because these zoonotic influenza viruses continue to circulate and adapt to new hosts. PMID:26611442

  14. Neutralizing inhibitors in the airways of naïve ferrets do not play a major role in modulating the virulence of H3 subtype influenza A viruses.

    PubMed

    Job, Emma R; Pizzolla, Angela; Nebl, Thomas; Short, Kirsty R; Deng, Yi-Mo; Carolan, Louise; Laurie, Karen L; Brooks, Andrew G; Reading, Patrick C

    2016-07-01

    Many insights regarding the pathogenesis of human influenza A virus (IAV) infections have come from studies in mice and ferrets. Surfactant protein (SP)-D is the major neutralizing inhibitor of IAV in mouse airway fluids and SP-D-resistant IAV mutants show enhanced virus replication and virulence in mice. Herein, we demonstrate that sialylated glycoproteins, rather than SP-D, represent the major neutralizing inhibitors against H3 subtype viruses in airway fluids from naïve ferrets. Moreover, while resistance to neutralizing inhibitors is a critical factor in modulating virus replication and disease in the mouse model, it does not appear to be so in the ferret model, as H3 mutants resistant to either SP-D or sialylated glycoproteins in ferret airway fluids did not show enhanced virulence in ferrets. These data have important implications for our understanding of pathogenesis and immunity to human IAV infections in these two widely used animal models of infection. PMID:27110707

  15. A brief introduction to avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is caused by a type A influenza virus isolated from and adapted to an avian host. This chapter covers the basic physicochemical aspects of AIV including; virus family and properties, subtype classification; basic molecular biology and genetics. The avian host range and ecology...

  16. Influenza-A viruses in ducks in northwestern Minnesota: fine scale spatial and temporal variation in prevalence and subtype diversity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterfowl from northwestern Minnesota were sampled by cloacal swabbing for Avian Influenza Virus (AIV) from July – October in 2007 and 2008. AIV was detected in 222 (9.1%) of 2,441 ducks in 2007 and in 438 (17.9%) of 2,452 ducks in 2008. Prevalence of AIV peaked in late summer. We detected 27 A...

  17. Isolation and molecular characterization of reassortant H11N3 subtype avian influenza viruses isolated from domestic ducks in Zhejiang Province in China.

    PubMed

    Wu, Haibo; Peng, Xiuming; Peng, Xiaorong; Wu, Nanping

    2016-10-01

    In July 2013, six H11N3 subtype avian influenza viruses (AIVs) were isolated from domestic ducks in Zhejiang Province in Eastern China. These strains were characterized by whole genome sequencing with subsequent phylogenetic analysis and genetic comparison. Phylogenetic analysis of all eight viral genes showed that these strains clustered in the AIV Eurasian lineage, and these strains received their genes from H11, H7, and H1 AIVs in Eastern China. These strains were found to be minimally pathogenic in mice, and were able to replicate in mice without prior adaptation. Continued surveillance is needed considering the important role of domestic ducks in AIV reassortment. PMID:27142079

  18. SYBR green-based real-time reverse transcription-PCR for typing and subtyping of all hemagglutinin and neuraminidase genes of avian influenza viruses and comparison to standard serological subtyping tests

    USGS Publications Warehouse

    Tsukamoto, K.; Javier, P.C.; Shishido, M.; Noguchi, D.; Pearce, J.; Kang, H.-M.; Jeong, O.M.; Lee, Y.-J.; Nakanishi, K.; Ashizawa, T.

    2012-01-01

    Continuing outbreaks of H5N1 highly pathogenic (HP) avian influenza virus (AIV) infections of wild birds and poultry worldwide emphasize the need for global surveillance of wild birds. To support the future surveillance activities, we developed a SYBR green-based, real-time reverse transcriptase PCR (rRT-PCR) for detecting nucleoprotein (NP) genes and subtyping 16 hemagglutinin (HA) and 9 neuraminidase (NA) genes simultaneously. Primers were improved by focusing on Eurasian or North American lineage genes; the number of mixed-base positions per primer was set to five or fewer, and the concentration of each primer set was optimized empirically. Also, 30 cycles of amplification of 1:10 dilutions of cDNAs from cultured viruses effectively reduced minor cross- or nonspecific reactions. Under these conditions, 346 HA and 345 NA genes of 349 AIVs were detected, with average sensitivities of NP, HA, and NA genes of 10 1.5, 10 2.3, and 10 3.1 50% egg infective doses, respectively. Utility of rRT-PCR for subtyping AIVs was compared with that of current standard serological tests by using 104 recent migratory duck virus isolates. As a result, all HA genes and 99% of the NA genes were genetically subtyped, while only 45% of HA genes and 74% of NA genes were serologically subtyped. Additionally, direct subtyping of AIVs in fecal samples was possible by 40 cycles of amplification: approximately 70% of HA and NA genes of NP gene-positive samples were successfully subtyped. This validation study indicates that rRT-PCR with optimized primers and reaction conditions is a powerful tool for subtyping varied AIVs in clinical and cultured samples. Copyright ?? 2012, American Society for Microbiology. All Rights Reserved.

  19. Avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is type A influenza, which is adapted to an avian host. Although avian influenza has been isolated from numerous avian species, the primary natural hosts for the virus are dabbling ducks, shorebirds, and gulls. The virus can be found world-wide in these species and in o...

  20. Study of the duration and distribution of equine influenza virus subtype 2 (H3N8) antigens in experimentally infected ponies in vivo.

    PubMed

    Sutton, G A; Viel, L; Carman, P S; Boag, B L

    1997-04-01

    The purpose of this experiment was to study the duration and distribution of equine influenza virus in actively infected ponies over a 3 wk period. Pony foals (6-8 mo old) were infected experimentally by nebulizing equine influenza subtype-2 virus ultrasonically through a face mask. Successful infection was clinically apparent as each of the foals (n = 6) had a febrile response, a deep hacking cough and mucopurulent nasal discharge for 7 to 10 d. The virus was isolated from nasopharyngeal swabs of all the ponies 3 and 5 d after infection and all the ponies seroconverted to the virus. Samples were taken from the nasopharynx, mid-trachea and the mainstem bronchus with cytology brushes through an endoscope as well as from bronchoalveolar lavage fluid. On days 3 to 7 post-infection, ciliacytophtorea (the presence of cilia and ciliated plates separated from columnar epithelial cells) was recognized on routine cytological stain. Indirect immunoperoxidase staining utilizing polyclonal antibodies demonstrated viral antigen in intact and fragmented ciliated epithelial cells and in fragments of ciliated plates. The infected cells and cell fragments were particularly evident on days 3 and 5 post-infection in the nasopharynx, mid-trachea and mainstem bronchus and on days 3 to 7 post-infection in the bronchoalveolar lavage samples. On days 7 and 21 post-infection, viral antigen was identified in vacuoles of alveolar macrophage-like cells collected by bronchoalveolar lavage. It can be concluded from this study that equine influenza virus can infect not only the upper airways but also the bronchial epithelium and that viral antigen can persist up to 21 d post-infection. PMID:9114962

  1. The Detection of a Low Pathogenicity Avian Influenza Virus Subtype H9 Infection in a Turkey Breeder Flock in the United Kingdom.

    PubMed

    Reid, Scott M; Banks, Jill; Ceeraz, Vanessa; Seekings, Amanda; Howard, Wendy A; Puranik, Anita; Collins, Susan; Manvell, Ruth; Irvine, Richard M; Brown, Ian H

    2016-05-01

    In April 2013, an H9N2 low pathogenicity avian influenza (LPAI) virus was isolated in a turkey breeder farm in Eastern England comprising 4966 birds. Point-of-lay turkey breeding birds had been moved from a rearing site and within 5 days had shown rapid onset of clinical signs of dullness, coughing, and anorexia. Three houses were involved, two contained a total of 4727 turkey hens, and the third housed 239 male turkeys. Around 50% of the hens were affected, whereas the male turkeys demonstrated milder clinical signs. Bird morbidity rose from 10% to 90%, with an increase in mortality in both houses of turkey hens to 17 dead birds in one house and 27 birds in the second house by day 6. The birds were treated with an antibiotic but were not responsive. Postmortem investigation revealed air sacculitis but no infraorbital sinus swellings or sinusitis. Standard samples were collected, and influenza A was detected. H9 virus infection was confirmed in all three houses by detection and subtyping of hemagglutinating agents in embryonated specific-pathogen-free fowls' eggs, which were shown to be viruses of H9N2 subtype using neuraminidase inhibition tests and a suite of real-time reverse transcription PCR assays. LPAI virus pathotype was suggested by cleavage site sequencing, and an intravenous pathogenicity index of 0.00 confirmed that the virus was of low pathogenicity. Therefore, no official disease control measures were required, and despite the high morbidity, birds recovered and were kept in production. Neuraminidase sequence analysis revealed a deletion of 78 nucleotides in the stalk region, suggesting an adaptation of the virus to poultry. Hemagglutinin gene sequences of two of the isolates clustered with a group of H9 viruses containing other contemporary European H9 strains in the Y439/Korean-like group. The closest matches to the two isolates were A/turkey/Netherlands/11015452/11 (H9N2; 97.9-98% nucleotide identity) and A/mallard/Finland/Li13384/10 (H9N2; 97

  2. Evolution and ecology of influenza A viruses.

    PubMed Central

    Webster, R G; Bean, W J; Gorman, O T; Chambers, T M; Kawaoka, Y

    1992-01-01

    In this review we examine the hypothesis that aquatic birds are the primordial source of all influenza viruses in other species and study the ecological features that permit the perpetuation of influenza viruses in aquatic avian species. Phylogenetic analysis of the nucleotide sequence of influenza A virus RNA segments coding for the spike proteins (HA, NA, and M2) and the internal proteins (PB2, PB1, PA, NP, M, and NS) from a wide range of hosts, geographical regions, and influenza A virus subtypes support the following conclusions. (i) Two partly overlapping reservoirs of influenza A viruses exist in migrating waterfowl and shorebirds throughout the world. These species harbor influenza viruses of all the known HA and NA subtypes. (ii) Influenza viruses have evolved into a number of host-specific lineages that are exemplified by the NP gene and include equine Prague/56, recent equine strains, classical swine and human strains, H13 gull strains, and all other avian strains. Other genes show similar patterns, but with extensive evidence of genetic reassortment. Geographical as well as host-specific lineages are evident. (iii) All of the influenza A viruses of mammalian sources originated from the avian gene pool, and it is possible that influenza B viruses also arose from the same source. (iv) The different virus lineages are predominantly host specific, but there are periodic exchanges of influenza virus genes or whole viruses between species, giving rise to pandemics of disease in humans, lower animals, and birds. (v) The influenza viruses currently circulating in humans and pigs in North America originated by transmission of all genes from the avian reservoir prior to the 1918 Spanish influenza pandemic; some of the genes have subsequently been replaced by others from the influenza gene pool in birds. (vi) The influenza virus gene pool in aquatic birds of the world is probably perpetuated by low-level transmission within that species throughout the year. (vii

  3. Replication and transmission of influenza viruses in Japanese quail

    PubMed Central

    Makarova, Natalia V.; Ozaki, Hiroishi; Kida, Hiroshi; Webster, Robert G.; Perez, Daniel R.

    2015-01-01

    Quail have emerged as a potential intermediate host in the spread of avian influenza A viruses in poultry in Hong Kong. To better understand this possible role, we tested the replication and transmission in quail of influenza A viruses of all 15 HA subtypes. Quail supported the replication of at least 14 subtypes. Influenza A viruses replicated predominantly in the respiratory tract. Transmission experiments suggested that perpetuation of avian influenza viruses in quail requires adaptation. Swine influenza viruses were isolated from the respiratory tract of quail at low levels. There was no evidence of human influenza A or B virus replication. Interestingly, a human–avian recombinant containing the surface glycoprotein genes of a quail virus and the internal genes of a human virus replicated and transmitted readily in quail; therefore, quail could function as amplifiers of influenza virus reassortants that have the potential to infect humans and/or other mammalian species. PMID:12788625

  4. First reported detection of a low pathogenicity avian influenza virus subtype H9 infection in domestic fowl in England.

    PubMed

    Parker, C D; Reid, S M; Ball, A; Cox, W J; Essen, S C; Hanna, A; Mahmood, S; Slomka, M J; Irvine, R M; Brown, I H

    2012-10-13

    In December 2010, infection with a H9N1 low pathogenicity avian influenza (LPAI) virus was detected in a broiler breeder flock in East Anglia. Disease suspicion was based on acute drops in egg production in two of four sheds on the premises, poor egg shell quality and evidence of diarrhoea. H9N1 LPAI virus infection was confirmed by real-time reverse transcription PCR. Sequencing revealed high nucleotide identity of 93.6 per cent and 97.9 per cent with contemporary North American H9 and Eurasian N1 genes, respectively. Attempted virus isolation in embryonated specific pathogen free (SPF) fowls' eggs was unsuccessful. Epidemiological investigations were conducted to identify the source of infection and any onward spread. These concluded that infection was restricted to the affected premises, and no contacts or movements of poultry, people or fomites could be attributed as the source of infection. However, the infection followed a period of extremely cold weather and snow which impacted on the biosecurity protocols on site, and also led to increased wild bird activity locally, including waterfowl and game birds around the farm buildings. Analysis of the N1 gene sequence suggested direct introduction from wild birds. Although H9 infection in poultry is not notifiable, H9N2 LPAI viruses have been associated with production and mortality episodes in poultry in many parts of Asia and the Middle East. In the present H9N1 outbreak, clinical signs were relatively mild in the poultry with no mortality, transient impact on egg production and no indication of zoonotic spread. However, this first reported detection of H9 LPAI virus in chickens in England was also the first H9 UK poultry case for 40 years, and vindicates the need for continued vigilance and surveillance of avian influenza viruses in poultry populations. PMID:22949546

  5. Analytical validation of a real-time reverse transcription polymerase chain reaction test for Pan-American lineage H7 subtype Avian influenza viruses

    USGS Publications Warehouse

    Spackman, Erica; Ip, H.S.; Suarez, D.L.; Slemons, R.D.; Stallknecht, D.E.

    2008-01-01

    A real-time reverse transcription polymerase chain reaction test for the identification of the H7 subtype in North American Avian influenza viruses (AIVs) was first reported in 2002; however, recent AIV surveillance efforts in wild birds and H7 outbreaks in poultry demonstrated that the 2002 test did not detect all H7 AIVs present in North and South America. Therefore, a new test, the 2008 Pan-American H7 test, was developed by using recently available H7 nucleotide sequences. The analytical specificity of the new assay was characterized with an RNA panel composed of 19 H7 viruses from around the world and RNA from all hemagglutinin subtypes except H16. Specificity for North and South American lineage H7 viruses was observed. Assay limits of detection were determined to be between 103 and 104 gene copies per reaction with in vitro transcribed RNA, and 100.0 and 10 0.8 50% egg infectious doses per reaction. The 2008 Pan-American H7 test also was shown to perform similarly to the 2002 test with specimens from chickens experimentally exposed to A/Chicken/BritishColumbia/314514-2/04 H7N3 highly pathogenic AIV. Furthermore, the 2008 test was able to detect 100% (n = 27) of the H7 AIV isolates recovered from North American wild birds in a 2006-2007 sample set (none of which were detected by the 2002 H7 test).

  6. The effect of the hexanic extracts of fig (Ficus carica) and olive (Olea europaea) fruit and nanoparticles of selenium on the immunogenicity of the inactivated avian influenza virus subtype H9N2

    PubMed Central

    Asl Najjari, Amir Hossein; Rajabi, Zolfaghar; Vasfi Marandi, Mehdi; Dehghan, Gholamreza

    2015-01-01

    Influenza is a contagious viral disease that is seen in avian, human and other mammals, so its control is important. Vaccination against influenza virus subtype H9N2 is one of the ways in controlling program, for this reason several vaccines has been produced. Recently, application of inactivated oil-emulsion vaccines in poultry for controlling low pathogenic avian influenza is increasing. At present, oils that are used as adjuvant in commercial vaccines are mineral oils, which not only lack immunizing effect, but also produce some detriments. The aim of this study is the evaluation the immunogenicity of vegetable oils, which are more metabolizable and safer than mineral oils. In this study the efficacy of hexanic extracts of fig (Ficus carica) and olive (Olea europaea) fruit and also nano-selenium on the immunogenicity of the inactivated avian influenza virus subtype H9N2 was evaluated in broiler chickens. The results indicated that the prepared emulsions could elicit a little degree of immunity, but they could not inhibit the anamnestic response and infection. With regard to the results, it seems that the intact mixture of fig and olive fruit hexanic extracts could not be administered as an immunoadjuvant in the vaccine, and about nano-selenium. In spite of positive effect on the immunogenicity of avian influenza virus subtype H9N2, it still needs more work. PMID:26893813

  7. The effect of the hexanic extracts of fig (Ficus carica) and olive (Olea europaea) fruit and nanoparticles of selenium on the immunogenicity of the inactivated avian influenza virus subtype H9N2.

    PubMed

    Asl Najjari, Amir Hossein; Rajabi, Zolfaghar; Vasfi Marandi, Mehdi; Dehghan, Gholamreza

    2015-01-01

    Influenza is a contagious viral disease that is seen in avian, human and other mammals, so its control is important. Vaccination against influenza virus subtype H9N2 is one of the ways in controlling program, for this reason several vaccines has been produced. Recently, application of inactivated oil-emulsion vaccines in poultry for controlling low pathogenic avian influenza is increasing. At present, oils that are used as adjuvant in commercial vaccines are mineral oils, which not only lack immunizing effect, but also produce some detriments. The aim of this study is the evaluation the immunogenicity of vegetable oils, which are more metabolizable and safer than mineral oils. In this study the efficacy of hexanic extracts of fig (Ficus carica) and olive (Olea europaea) fruit and also nano-selenium on the immunogenicity of the inactivated avian influenza virus subtype H9N2 was evaluated in broiler chickens. The results indicated that the prepared emulsions could elicit a little degree of immunity, but they could not inhibit the anamnestic response and infection. With regard to the results, it seems that the intact mixture of fig and olive fruit hexanic extracts could not be administered as an immunoadjuvant in the vaccine, and about nano-selenium. In spite of positive effect on the immunogenicity of avian influenza virus subtype H9N2, it still needs more work. PMID:26893813

  8. Avian influenza virus in pregnancy.

    PubMed

    Liu, Shelan; Sha, Jianping; Yu, Zhao; Hu, Yan; Chan, Ta-Chien; Wang, Xiaoxiao; Pan, Hao; Cheng, Wei; Mao, Shenghua; Zhang, Run Ju; Chen, Enfu

    2016-07-01

    The unprecedented epizootic of avian influenza viruses, such as H5N1, H5N6, H7N1 and H10N8, has continued to cause disease in humans in recent years. In 2013, another novel influenza A (H7N9) virus emerged in China, and 30% of those patients died. Pregnant women are particularly susceptible to avian influenza and are more likely to develop severe complications and to die, especially when infection occurs in the middle and late trimesters. Viremia is believed to occur infrequently, and thus vertical transmission induced by avian influenza appears to be rare. However, avian influenza increases the risk of adverse pregnancy outcomes, including spontaneous abortion, preterm birth and fatal distress. This review summarises 39 cases of pregnant women and their fetuses from different countries dating back to 1997, including 11, 15 and 13 infections with H7N9, H5N1 and the 2009 pandemic influenza (H1N1), respectively. We analysed the epidemic features, following the geographical, population and pregnancy trimester distributions; underlying diseases; exposure history; medical timelines; human-to-human transmission; pathogenicity and vertical transmission; antivirus treatments; maternal severity and mortality and pregnancy outcome. The common experiences reported in different countries and areas suggest that early identification and treatment are imperative. In the future, vigilant virologic and epidemiologic surveillance systems should be developed to monitor avian influenza viruses during pregnancy. Furthermore, extensive study on the immune mechanisms should be conducted, as this will guide safe, rational immunomodulatory treatment among this high-risk population. Most importantly, we should develop a universal avian influenza virus vaccine to prevent outbreaks of the different subtypes. Copyright © 2016 John Wiley & Sons, Ltd. PMID:27187752

  9. Development and evaluation of an influenza subtype H7N2 vaccine candidate for pandemic preparedness

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza virus of the H7N2 subtype is enzootic among some wild aquatic birds of North America. This virus has been introduced into non-commercial poultry in the United States. Virus circulation in poultry probably resulted in incidents of transmission of H7N2 virus to humans documented in 2002 an...

  10. INFLUENZA VIRUS IN POULTRY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is normally found in wild birds, particularly in ducks and shorebirds, where it does not cause any perceptible clinical disease. However, poultry, including chickens and turkeys, are not normal hosts for avian influenza, but if the virus is introduced it can result in mi...

  11. Influenza A virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses are important veterinary and human health pathogens around the world. Avian influenza (AI) virus in poultry is unusual in that it can cause a range of disease symptoms from a subclinical infection to being highly virulent with 100% mortality. The difference between low pathogen...

  12. 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. PMID:26973600

  13. 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 Central

    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. PMID:26973600

  14. Chimaeric VP2 proteins from infectious bursal disease virus containing the N-terminal M2e of H9 subtype avian influenza virus induce neutralizing antibody responses to both viruses.

    PubMed

    Tang, Yinghua; Gong, Yuzhen; Wang, Yongwei; Wu, Peipei; Liu, Yamei; Lu, Jihu; Gao, Feng; Chen, Tao; Hou, Fengxiang; Hou, Jibo

    2013-01-01

    Subunit vaccines capable of inducing antibody against both infectious bursal disease virus (IBDV) and H9 subtype avian influenza virus (AIV) were developed. The VP2 protein of IBDV was used as a cargo protein to display a 12-amino-acid immunodominant epitope derived from the N-terminal M2 extracellular domain (nM2e) of the H9 subtype AIV. Two chimaeric proteins were constructed by insertion of one copy of the nM2e into the PBC region (VP2BCnM2e(H9)) or by fusing four copies of nM2e to the carboxyl terminal (VP2-4nM2e(H9)) of VP2. Genes that encoded the VP2 chimaeras were subsequently cloned into a baculovirus vector and expressed in Spodoptera frugiperda cells. The recombinant proteins were used to vaccinate chickens at day 0 and again after 4 weeks. Blood was collected at 2-week intervals after primary and secondary vaccination to detect the antibody titre against VP2 or the nM2e via indirect enzyme-linked immunosorbent assay. Virus neutralization tests were also performed to measure anti-IBDV or anti-H9 AIV neutralizing antibodies in chick embryo fibroblasts. Oropharyngeal and cloacal swabs were collected 3, 5 and 7 days post H9 subtype AIV infection for virus isolation. Vaccination with VP2-4nM2e(H9) induced higher levels of antibody responses against IBDV or H9 subtype AIV, and provided better protection against an IBDV virulent challenge compared with vaccination with VP2BCnM2e(H9) vaccine, the wild-type VP2 subunit vaccine or the IBDV subunit commercial vaccines. Both chimaeric VP2 vaccines showed poor efficacy in inhibiting H9 virus replication post challenge. In summary, chimaeric proteins that contain the nM2e epitope were able to induce both IBDV and H9 subtype AIV-neutralizing antibody responses. PMID:23607544

  15. Innate immune response to a H3N2 subtype swine influenza virus in newborn porcine trachea cells, alveolar macrophages, and precision-cut lung slices

    PubMed Central

    2014-01-01

    Viral respiratory diseases remain of major importance in swine breeding units. Swine influenza virus (SIV) is one of the main known contributors to infectious respiratory diseases. The innate immune response to swine influenza viruses has been assessed in many previous studies. However most of these studies were carried out in a single-cell population or directly in the live animal, in all its complexity. In the current study we report the use of a trachea epithelial cell line (newborn pig trachea cells – NPTr) in comparison with alveolar macrophages and lung slices for the characterization of innate immune response to an infection by a European SIV of the H3N2 subtype. The expression pattern of transcripts involved in the recognition of the virus, interferon type I and III responses, and the host-response regulation were assessed by quantitative PCR in response to infection. Some significant differences were observed between the three systems, notably in the expression of type III interferon mRNA. Then, results show a clear induction of JAK/STAT and MAPK signaling pathways in infected NPTr cells. Conversely, PI3K/Akt signaling pathways was not activated. The inhibition of the JAK/STAT pathway clearly reduced interferon type I and III responses and the induction of SOCS1 at the transcript level in infected NPTr cells. Similarly, the inhibition of MAPK pathway reduced viral replication and interferon response. All together, these results contribute to an increased understanding of the innate immune response to H3N2 SIV and may help identify strategies to effectively control SIV infection. PMID:24712747

  16. Epidemiological survey and genetic evolution of H9 subtype influenza viruses in Shanghai, China, from 2006 to 2010.

    PubMed

    Zhou, Jin-Ping; Ge, Fei-Fei; Liu, Jian; Ju, Hou-Bing; Yang, De-Quan; Wang, Jian; Zhang, Wei-Yi; Liu, Pei-Hong

    2012-06-01

    The H9N2 influenza virus is endemic in poultry. We report its occurrence in live-poultry markets, fair-trade markets and poultry farms in the Shanghai region between September 2006 and December 2010. An analysis of partial sequences of the HA, NA, PB1, PB2 and NP genes of eleven distinct H9N2 isolates revealed that all carried an RSSR motif at the cleavage site of HA, diagnostic of low pathogenicity in chickens. A phylogenetic analysis indicated that these isolates are derived from the lineage represented by Duck/HK/Y280/97, but they have evolved a range of reassortments. Their PB1 and NP sequences resembled those of H5N1 strains, indicating a hybrid origin involving both H9 and H5 strains. The HA and NA sequences present in all eleven isolates resembled those of the Duck/HK/Y280/97-like lineage. Infection by H9N2 is commonplace in Shanghai live-poultry markets, allowing the viruses to have evolved rapidly. PMID:22407404

  17. New vaccines against influenza virus

    PubMed Central

    Lee, Young-Tae; Kim, Ki-Hye; Ko, Eun-Ju; Lee, Yu-Na; Kim, Min-Chul; Kwon, Young-Man; Tang, Yinghua; Cho, Min-Kyoung; Lee, Youn-Jeong

    2014-01-01

    Vaccination is one of the most effective and cost-benefit interventions that prevent the mortality and reduce morbidity from infectious pathogens. However, the licensed influenza vaccine induces strain-specific immunity and must be updated annually based on predicted strains that will circulate in the upcoming season. Influenza virus still causes significant health problems worldwide due to the low vaccine efficacy from unexpected outbreaks of next epidemic strains or the emergence of pandemic viruses. Current influenza vaccines are based on immunity to the hemagglutinin antigen that is highly variable among different influenza viruses circulating in humans and animals. Several scientific advances have been endeavored to develop universal vaccines that will induce broad protection. Universal vaccines have been focused on regions of viral proteins that are highly conserved across different virus subtypes. The strategies of universal vaccines include the matrix 2 protein, the hemagglutinin HA2 stalk domain, and T cell-based multivalent antigens. Supplemented and/or adjuvanted vaccination in combination with universal target antigenic vaccines would have much promise. This review summarizes encouraging scientific advances in the field with a focus on novel vaccine designs. PMID:24427759

  18. Human Influenza Virus Infections.

    PubMed

    Peteranderl, Christin; Herold, Susanne; Schmoldt, Carole

    2016-08-01

    Seasonal and pandemic influenza are the two faces of respiratory infections caused by influenza viruses in humans. As seasonal influenza occurs on an annual basis, the circulating virus strains are closely monitored and a yearly updated vaccination is provided, especially to identified risk populations. Nonetheless, influenza virus infection may result in pneumonia and acute respiratory failure, frequently complicated by bacterial coinfection. Pandemics are, in contrary, unexpected rare events related to the emergence of a reassorted human-pathogenic influenza A virus (IAV) strains that often causes increased morbidity and spreads extremely rapidly in the immunologically naive human population, with huge clinical and economic impact. Accordingly, particular efforts are made to advance our knowledge on the disease biology and pathology and recent studies have brought new insights into IAV adaptation mechanisms to the human host, as well as into the key players in disease pathogenesis on the host side. Current antiviral strategies are only efficient at the early stages of the disease and are challenged by the genomic instability of the virus, highlighting the need for novel antiviral therapies targeting the pulmonary host response to improve viral clearance, reduce the risk of bacterial coinfection, and prevent or attenuate acute lung injury. This review article summarizes our current knowledge on the molecular basis of influenza infection and disease progression, the key players in pathogenesis driving severe disease and progression to lung failure, as well as available and envisioned prevention and treatment strategies against influenza virus infection. PMID:27486731

  19. Genetic characterization of avian influenza subtype H4N6 and H4N9 from live bird market, Thailand

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A one year active surveillance program for influenza A viruses among avian species in a live-bird market (LBM) in Bangkok, Thailand was conducted in 2009. Out of 970 samples collected, influenza A virus subtypes H4N6 (n=2) and H4N9 (n=1), were isolated from healthy Muscovy ducks. All three viruses w...

  20. The evolution of human influenza viruses.

    PubMed Central

    Hay, A J; Gregory, V; Douglas, A R; Lin, Y P

    2001-01-01

    The evolution of influenza viruses results in (i) recurrent annual epidemics of disease that are caused by progressive antigenic drift of influenza A and B viruses due to the mutability of the RNA genome and (ii) infrequent but severe pandemics caused by the emergence of novel influenza A subtypes to which the population has little immunity. The latter characteristic is a consequence of the wide antigenic diversity and peculiar host range of influenza A viruses and the ability of their segmented RNA genomes to undergo frequent genetic reassortment (recombination) during mixed infections. Contrasting features of the evolution of recently circulating influenza AH1N1, AH3N2 and B viruses include the rapid drift of AH3N2 viruses as a single lineage, the slow replacement of successive antigenic variants of AH1N1 viruses and the co-circulation over some 25 years of antigenically and genetically distinct lineages of influenza B viruses. Constant monitoring of changes in the circulating viruses is important for maintaining the efficacy of influenza vaccines in combating disease. PMID:11779385

  1. Continuing Threat of Influenza (H5N1) Virus Circulation in Egypt

    PubMed Central

    El-Shesheny, Rabeh; Kutkat, Mohamed A.; Kandeil, Ahmed M.; Mostafa, Ahmed; Ducatez, Mariette F.; McKenzie, Pamela P.; Govorkova, Elena A.; Nasraa, Mohamed H.; Webster, Robert G.; Webby, Richard J.; Ali, Mohamed A.

    2011-01-01

    Reservoirs for the continuing influenza (H5N1) outbreaks in Egypt are ill-defined. Through active surveillance, we detected highly pathogenic influenza subtype H5 viruses in all poultry sectors; incidence was 5%. No other subtypes were found. Continued circulation of influenza (H5N1) viruses in various regions and poultry sectors perpetuates human exposure in Egypt. PMID:22172626

  2. Prepandemic influenza vaccine H5N1 (split virion, inactivated, adjuvanted) [Prepandrix]: a review of its use as an active immunization against influenza A subtype H5N1 virus.

    PubMed

    Carter, Natalie J; Plosker, Greg L

    2008-01-01

    Although rare, influenza pandemics are a recurrent event, and influenza A/H5N1 is generally considered to be the most likely causative agent of the next pandemic. Vaccines are widely considered to be the first line of defense for protecting populations in advance of an influenza pandemic. Because it is not known beforehand which strain of influenza A/H5N1 virus could give rise to a pandemic, prepandemic vaccines that impart broad cross-reactive immunogenicity are required. In addition, low doses of H5 hemagglutinin are preferable in order to make antigen supplies go further towards meeting global demands for prepandemic vaccines.Prepandemic influenza vaccine H5N1 [Prepandrix(trade mark); AS03-H5N1 vaccine] is a split virion, inactivated vaccine containing H5 hemagglutinin antigen adjuvanted with a novel 10% oil-in-water emulsion-based adjuvant system (AS03). It is approved in the EU for use as an active immunization against H5N1 subtype influenza A virus (influenza A/H5N1 virus) in adults aged 18-60 years. The recommended dosage in this population is two doses of 0.5 mL containing 3.75 microg of H5 hemagglutinin, administered > or =21 days apart. Adjuvantation of H5N1 vaccine with AS03 allows for a reduction in the H5 hemagglutinin dose required to elicit an adequate immune response, and administration of two doses of the adjuvanted vaccine met all criteria for the licensure of influenza vaccines set out in European Committee for Proprietary Medicinal Products (CPMP) and US FDA documents. In two clinical trials, two doses of AS03-H5N1 vaccine containing 3.75 microg of H5 hemagglutinin induced an immune response in healthy volunteers aged 18-60 years against the homologous, clade 1 vaccine strain, A/Vietnam/1194/2004, and the heterologous, drifted, clade 2 nonvaccine strains, A/Anhui/1/2005, A/Indonesia/5/2005, and A/turkey/Turkey/1/2005. This cross-clade response persisted for > or =6 months following administration of the first vaccine dose in the majority of

  3. Recent zoonoses caused by influenza A viruses.

    PubMed

    Alexander, D J; Brown, I H

    2000-04-01

    Influenza is a highly contagious, acute illness which has afflicted humans and animals since ancient times. Influenza viruses are part of the Orthomyxoviridae family and are grouped into types A, B and C according to antigenic characteristics of the core proteins. Influenza A viruses infect a large variety of animal species, including humans, pigs, horses, sea mammals and birds, occasionally producing devastating pandemics in humans, such as in 1918, when over twenty million deaths occurred world-wide. The two surface glycoproteins of the virus, haemagglutinin (HA) and neuraminidase (NA), are the most important antigens for inducing protective immunity in the host and therefore show the greatest variation. For influenza A viruses, fifteen antigenically distinct HA subtypes and nine NA subtypes are recognised at present; a virus possesses one HA and one NA subtype, apparently in any combination. Although viruses of relatively few subtype combinations have been isolated from mammalian species, all subtypes, in most combinations, have been isolated from birds. In the 20th Century, the sudden emergence of antigenically different strains in humans, termed antigenic shift, has occurred on four occasions, as follows, in 1918 (H1N1), 1957 (H2N2), 1968 (H3N2) and 1977 (H1N1), each resulting in a pandemic. Frequent epidemics have occurred between the pandemics as a result of gradual antigenic change in the prevalent virus, termed antigenic drift. Currently, epidemics occur throughout the world in the human population due to infection with influenza A viruses of subtypes H1N1 and H3N2 or with influenza B virus. The impact of these epidemics is most effectively measured by monitoring excess mortality due to pneumonia and influenza. Phylogenetic studies suggest that aquatic birds could be the source of all influenza A viruses in other species. Human pandemic strains are thought to have emerged through one of the following three mechanisms: genetic reassortment (occurring as a

  4. Swine Influenza/Variant Influenza Viruses

    MedlinePlus

    ... Humans Key Facts about Human Infections with Variant Viruses Interim Guidance for Clinicians on Human Infections Background, Risk Assessment & Reporting Reported Infections with Variant Influenza Viruses in the United States since 2005 Prevention Treatment ...

  5. Viral Reassortment and Transmission after Coinfection of Pigs with two Swine Influenza Viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses of subtypes H3N2, H1N1 and H1N2 are circulating in U.S. swine. Because influenza A virus contains 8 RNA segments, genetic reassortment can take place when 2 or more influenza viruses infect the same cell. We studied the reassortment potential and transmissibility of swine influen...

  6. Novel reassortant influenza viruses between pandemic (H1N1) 2009 and other influenza viruses pose a risk to public health.

    PubMed

    Kong, Weili; Wang, Feibing; Dong, Bin; Ou, Changbo; Meng, Demei; Liu, Jinhua; Fan, Zhen-Chuan

    2015-12-01

    Influenza A virus (IAV) is characterized by eight single-stranded, negative sense RNA segments, which allows for gene reassortment among different IAV subtypes when they co-infect a single host cell simultaneously. Genetic reassortment is an important way to favor the evolution of influenza virus. Novel reassortant virus may pose a pandemic among humans. In history, three human pandemic influenza viruses were caused by genetic reassortment between avian, human and swine influenza viruses. Since 2009, pandemic (H1N1) 2009 (pdm/09 H1N1) influenza virus composed of two swine influenza virus genes highlighted the genetic reassortment again. Due to wide host species and high transmission of the pdm/09 H1N1 influenza virus, many different avian, human or swine influenza virus subtypes may reassert with it to generate novel reassortant viruses, which may result in a next pandemic among humans. So, it is necessary to understand the potential threat of current reassortant viruses between the pdm/09 H1N1 and other influenza viruses to public health. This study summarized the status of the reassortant viruses between the pdm/09 H1N1 and other influenza viruses of different species origins in natural and experimental conditions. The aim of this summarization is to facilitate us to further understand the potential threats of novel reassortant influenza viruses to public health and to make effective prevention and control strategies for these pathogens. PMID:26344393

  7. Sialic acid content in human saliva and anti-influenza activity against human and avian influenza viruses.

    PubMed

    Limsuwat, Nattavatchara; Suptawiwat, Ornpreya; Boonarkart, Chompunuch; Puthavathana, Pilaipan; Wiriyarat, Witthawat; Auewarakul, Prasert

    2016-03-01

    It was shown previously that human saliva has higher antiviral activity against human influenza viruses than against H5N1 highly pathogenic avian influenza viruses, and that the major anti-influenza activity was associated with sialic-acid-containing molecules. To further characterize the differential susceptibility to saliva among influenza viruses, seasonal influenza A and B virus, pandemic H1N1 virus, and 15 subtypes of avian influenza virus were tested for their susceptibility to human and chicken saliva. Human saliva showed higher hemagglutination inhibition (HI) and neutralization (NT) titers against seasonal influenza A virus and the pandemic H1N1 viruses than against influenza B virus and most avian influenza viruses, except for H9N2 and H12N9 avian influenza viruses, which showed high HI and NT titers. To understand the nature of sialic-acid-containing anti-influenza factors in human saliva, α2,3- and α2,6-linked sialic acid was measured in human saliva samples using a lectin binding and dot blot assay. α2,6-linked sialic acid was found to be more abundant than α2,3-linked sialic acid, and a seasonal H1N1 influenza virus bound more efficiently to human saliva than an H5N1 virus in a dot blot analysis. These data indicated that human saliva contains the sialic acid type corresponding to the binding preference of seasonal influenza viruses. PMID:26671828

  8. Monitoring of avian influenza viruses subtypes H5 and H7 in wild birds in the Azov-Black Sea region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. To date, influenza remains an unpredictable infection for animals, birds and people. The constant emergence of new strains and variants with new properties and pathogenicity for new hosts requires constant monitoring and careful research of new viruses. Since the main and primary reser...

  9. A heterologous neuraminidase subtype strategy for the differentiation of infected and vaccinated animals (DIVA) for avian influenza virus using an alternative neuraminidase inhibition test

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The option of vaccinating poultry against avian influenza (AI) as a control tool is gaining greater acceptance by governments and the poultry industry world wide. One reservation about vaccination with killed whole virus vaccines is the loss of the ability to use commonly used serologic surveillanc...

  10. Issues encountered in development of enzyme-linked immunosorbent assay for use in detecting influenza A virus subtype H5N1 exposure in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A potential mechanism by which highly pathogenic avian influenza H5N1 viruses could become established in humans is through the infection of and adaptation in pigs. To detect the occurrence of such adaptation, monitoring of the pig populations in endemic H5N1 areas through serological screening woul...

  11. A heterologous neuraminidase subtype strategy for the differentiation of vaccinated and infected animals (DIVA) strategy for avian influenza virus using a more flexible neuraminidase inhibition test in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The option of vaccinating poultry against avian influenza (AI) as a control tool is gaining greater acceptance by the government and poultry industry world-wide. One reservation about vaccination with killed whole virus vaccines is the loss of the ability to use serologic surveillance to identify i...

  12. Virus-Vectored Influenza Virus Vaccines

    PubMed Central

    Tripp, Ralph A.; Tompkins, S. Mark

    2014-01-01

    Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformulation of seasonal influenza vaccines. Recombinant virus-vectored vaccines are an appealing alternative to classical inactivated vaccines because virus vectors enable native expression of influenza antigens, even from virulent influenza viruses, while expressed in the context of the vector that can improve immunogenicity. In addition, a vectored vaccine often enables delivery of the vaccine to sites of inductive immunity such as the respiratory tract enabling protection from influenza virus infection. Moreover, the ability to readily manipulate virus vectors to produce novel influenza vaccines may provide the quickest path toward a universal vaccine protecting against all influenza viruses. This review will discuss experimental virus-vectored vaccines for use in humans, comparing them to licensed vaccines and the hurdles faced for licensure of these next-generation influenza virus vaccines. PMID:25105278

  13. Evaluation of Alere i Influenza A&B for rapid detection of influenza viruses A and B.

    PubMed

    Nie, Shuping; Roth, Richard B; Stiles, Jeffrey; Mikhlina, Albina; Lu, Xuedong; Tang, Yi-Wei; Babady, N Esther

    2014-09-01

    Rapid and accurate diagnosis of influenza is important for infection control, as well as for patient management. Alere i Influenza A&B is an isothermal nucleic acid amplification-based integrated system for detection and differentiation of influenza virus A and influenza virus B. The performance of the Alere i Influenza A&B was screened using frozen nasopharyngeal-swab specimens collected in viral transport medium (VTM) that were originally tested fresh with the FilmArray Respiratory Panel (RP) assay during the 2012-2013 influenza outbreak. In total, 360 VTM specimens were selected for Alere i Influenza A&B testing: 40 influenza virus A H1N1-2009 (influenza virus A-1), 40 influenza virus A H3N2 (influenza virus A-3), 37 influenza virus A "equivocal" or "no subtype detected" (influenza virus A-u), 41 influenza virus B, and 202 influenza virus-negative specimens, as initially determined by the FilmArray RP assay. The Alere assay showed sensitivities of 87.2%, 92.5%, 25.0%, and 97.4% for influenza virus A-1, influenza virus A-3, influenza virus A-u, and influenza virus B, respectively, after discordant resolution by Prodesse ProFLU+ PCR. The specificities were 100% for both influenza virus A and influenza virus B. In general, the Alere i Influenza A&B provided good sensitivity, although the assay did show poorer sensitivity with samples determined to have low influenza virus A titers by Prodesse ProFlu+ PCR (a mean real-time PCR threshold cycle [CT] value of 31.9 ± 2.0), which included the majority of the samples called influenza virus A "equivocal" or "no subtype detected" by a single BioFire FilmArray RP test. The integrated, rapid, and simple characteristics of the Alere i Influenza A&B assay make it a potential candidate for point-of-care testing, with a test turnaround time of less than 15 min. PMID:24989611

  14. Experimental co-infection of SPF chickens with low pathogenicity avian influenza virus (LPAIV) subtypes H9N2, H5N2 and H7N9, and infectious bronchitis virus (IBV)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) and infectious bronchitis virus (IBV) are two of the most important respiratory viruses affecting poultry worldwide, but little is known about the effect of co-infection of these two viruses in poultry. Low pathogenicity (LP) AIV can produce from mild to moderate upper r...

  15. Pandemic Threat Posed by Avian Influenza A Viruses

    PubMed Central

    Horimoto, Taisuke; Kawaoka, Yoshihiro

    2001-01-01

    Influenza pandemics, defined as global outbreaks of the disease due to viruses with new antigenic subtypes, have exacted high death tolls from human populations. The last two pandemics were caused by hybrid viruses, or reassortants, that harbored a combination of avian and human viral genes. Avian influenza viruses are therefore key contributors to the emergence of human influenza pandemics. In 1997, an H5N1 influenza virus was directly transmitted from birds in live poultry markets in Hong Kong to humans. Eighteen people were infected in this outbreak, six of whom died. This avian virus exhibited high virulence in both avian and mammalian species, causing systemic infection in both chickens and mice. Subsequently, another avian virus with the H9N2 subtype was directly transmitted from birds to humans in Hong Kong. Interestingly, the genes encoding the internal proteins of the H9N2 virus are genetically highly related to those of the H5N1 virus, suggesting a unique property of these gene products. The identification of avian viruses in humans underscores the potential of these and similar strains to produce devastating influenza outbreaks in major population centers. Although highly pathogenic avian influenza viruses had been identified before the 1997 outbreak in Hong Kong, their devastating effects had been confined to poultry. With the Hong Kong outbreak, it became clear that the virulence potential of these viruses extended to humans. PMID:11148006

  16. Predicting Hotspots for Influenza Virus Reassortment

    PubMed Central

    Gilbert, Marius; Martin, Vincent; Cappelle, Julien; Hosseini, Parviez; Njabo, Kevin Y.; Abdel Aziz, Soad; Xiao, Xiangming; Daszak, Peter; Smith, Thomas B.

    2013-01-01

    The 1957 and 1968 influenza pandemics, each of which killed ≈1 million persons, arose through reassortment events. Influenza virus in humans and domestic animals could reassort and cause another pandemic. To identify geographic areas where agricultural production systems are conducive to reassortment, we fitted multivariate regression models to surveillance data on influenza A virus subtype H5N1 among poultry in China and Egypt and subtype H3N2 among humans. We then applied the models across Asia and Egypt to predict where subtype H3N2 from humans and subtype H5N1 from birds overlap; this overlap serves as a proxy for co-infection and in vivo reassortment. For Asia, we refined the prioritization by identifying areas that also have high swine density. Potential geographic foci of reassortment include the northern plains of India, coastal and central provinces of China, the western Korean Peninsula and southwestern Japan in Asia, and the Nile Delta in Egypt. PMID:23628436

  17. Synthesis of 1,2,3-triazolyl nucleoside analogs as potential anti-influenza A (H3N2 subtype) virus agents.

    PubMed

    Elayadi, Hanane; Smietana, Michael; Vasseur, Jean J; Balzarini, Jan; Lazrek, Hassan B

    2014-02-01

    Montmorillonite K10 impregnated with copper dichloride and potassium iodide (CuCl2 /KI/K10) was used as catalyst in the cycloaddition of azides and propargylnucleobases, to provide the corresponding 1,4-disubstituted 1,2,3-triazoles in good yield. All compounds 16-23 were evaluated for their antiviral activity in vitro. Compound 18 showed moderate inhibition against influenza virus A (H3N2). PMID:24272912

  18. Immunogenicity and efficacy of a recombinant adenovirus expressing hemagglutinin from the H5N1 subtype of swine influenza virus in mice.

    PubMed

    Wu, Yunpu; Qiao, Chuanling; Yang, Huanliang; Chen, Yan; Xin, Xiaoguang; Chen, Hualan

    2014-04-01

    The H5N1 influenza viruses infect a range of avian species and have recently been isolated from humans and pigs. In this study we generated a replication-defective recombinant adenovirus (rAd-H5HA-EGFP) expressing the hemagglutinin (HA) gene of H5N1 A/Swine/Fujian/1/2001 (SW/FJ/1/01) and evaluated its immunogenicity and protective efficacy in BALB/c mice. The recombinant virus induced high levels of hemagglutination inhibition (HI) antibody at a median tissue culture infective dose of 10(8) or 10(7). Compared with mice in the control groups, the mice vaccinated with rAd-H5HA-EGFP did not show apparent weight loss after challenge with either the homologous SW/FJ/1/01 or the heterologous H5N1 A/Chicken/Hunan/77/2005 (CK/HuN/77/05). Replication of the challenge virus was partially or completely inhibited, and viruses were detected at significantly lower numbers in the organs of the vaccinated mice, all of which survived the challenge with CK/HuN/77/05, whereas most of the control mice did not. These results indicate that rAd-H5HA-EGFP can provide effective immune protection from highly pathogenic H5N1 viruses in mice and is therefore a promising new candidate vaccine against H5N1 influenza in animals. PMID:24688173

  19. Highly Pathogenic Avian Influenza Virus Subtype H5N1 in Africa: A Comprehensive Phylogenetic Analysis and Molecular Characterization of Isolates

    PubMed Central

    Cattoli, Giovanni; Monne, Isabella; Fusaro, Alice; Joannis, Tony M.; Lombin, Lami H.; Aly, Mona M.; Arafa, Abdel S.; Sturm-Ramirez, Katharine M.; Couacy-Hymann, Emmanuel; Awuni, Joseph A.; Batawui, Komla B.; Awoume, Kodzo A.; Aplogan, Gilbert L.; Sow, Adama; Ngangnou, Andrè C.; El Nasri Hamza, Iman M.; Gamatié, Djibo; Dauphin, Gwenaelle; Domenech, Joseph M.; Capua, Ilaria

    2009-01-01

    Highly pathogenic avian influenza virus A/H5N1 was first officially reported in Africa in early 2006. Since the first outbreak in Nigeria, this virus spread rapidly to other African countries. From its emergence to early 2008, 11 African countries experienced A/H5N1 outbreaks in poultry and human cases were also reported in three of these countries. At present, little is known of the epidemiology and molecular evolution of A/H5N1 viruses in Africa. We have generated 494 full gene sequences from 67 African isolates and applied molecular analysis tools to a total of 1,152 A/H5N1 sequences obtained from viruses isolated in Africa, Europe and the Middle East between 2006 and early 2008. Detailed phylogenetic analyses of the 8 gene viral segments confirmed that 3 distinct sublineages were introduced, which have persisted and spread across the continent over this 2-year period. Additionally, our molecular epidemiological studies highlighted the association between genetic clustering and area of origin in a majority of cases. Molecular signatures unique to strains isolated in selected areas also gave us a clearer picture of the spread of A/H5N1 viruses across the continent. Mutations described as typical of human influenza viruses in the genes coding for internal proteins or associated with host adaptation and increased resistance to antiviral drugs have also been detected in the genes coding for transmembrane proteins. These findings raise concern for the possible human health risk presented by viruses with these genetic properties and highlight the need for increased efforts to monitor the evolution of A/H5N1 viruses across the African continent. They further stress how imperative it is to implement sustainable control strategies to improve animal and public health at a global level. PMID:19290041

  20. Development of Framework for Assessing Influenza Virus Pandemic Risk

    PubMed Central

    Burke, Stephen A.; Cox, Nancy J.

    2015-01-01

    Although predicting which influenza virus subtype will cause the next pandemic is not yet possible, public health authorities must continually assess the pandemic risk associated with animal influenza viruses, particularly those that have caused infections in humans, and determine what resources should be dedicated to mitigating that risk. To accomplish this goal, a risk assessment framework was created in collaboration with an international group of influenza experts. Compared with the previously used approach, this framework, named the Influenza Risk Assessment Tool, provides a systematic and transparent approach for assessing and comparing threats posed primarily by avian and swine influenza viruses. This tool will be useful to the international influenza community and will remain flexible and responsive to changing information. PMID:26196098

  1. The appearance of H3 influenza viruses in seals.

    PubMed

    Callan, R J; Early, G; Kida, H; Hinshaw, V S

    1995-01-01

    Surveillance for influenza A virus infection of seals has continued following the association of influenza A virus with epizootics of pneumonia in seals off the New England coast in 1979-1980 and 1982-1983. In January 1991 and January to February 1992, influenza A viruses were isolated from seals that died of pneumonia along the Cape Cod peninsula of Massachusetts. Antigenic characterization identified two H4N6 and three H3N3 viruses. This was the first isolation of H3 influenza viruses from seals, although this subtype is frequently detected in birds, pigs, horses and humans. Haemagglutination inhibition assays of the H3 isolates showed two distinct antigenic reactivity patterns: one more similar to an avian reference virus (A/Duck/Ukraine/1/63) and one more similar to a human virus (A/Aichi/2/68). The haemagglutinin (HA) genes from two of the H3 seal viruses showing different antigenic reactivity (A/Seal/MA/3911/92 and A/Seal/MA/3984/92) were 99.7% identical, with four nucleotide differences accounting for four amino acid differences. Phylogenetic analysis demonstrated that both of these sequences were closely related to the sequence from the avian H3 virus, A/Mallard/New York/6874/78. This indicates that influenza A viruses of apparent avian origin, including the H3 subtype viruses, continue to infect seals. PMID:7844533

  2. Isolation of an influenza A virus of unusual subtype (H1N7) from pigs in England, and the subsequent experimental transmission from pig to pig.

    PubMed

    Brown, I H; Alexander, D J; Chakraverty, P; Harris, P A; Manvell, R J

    1994-03-01

    A novel H1N7 influenza virus (A/swine/Eng/191973/92) was isolated from nasal swabs collected from two pigs on a farm where there had been recent clinical disease due to infection with an H1N1 virus (A/swine/Eng/195852/92). Antigenically, the haemagglutinin (HA) of the H1N7 virus was related most closely to the HA of A/USSR/90/77, whilst the neuraminidase (NA) appeared to be related most closely to the NA of A/equine/Prague/1/56 (H7N7). Pigs infected experimentally with A/swine/Eng/191973/92 developed mild clinical signs, excreted virus into the nasal passages for up to nine days after infection, appeared normal at necropsy, transmitted the virus to sentinel pigs, but seven out of eight pigs failed to seroconvert. These findings suggest that the H1N7 virus has a low pathogenicity for pigs, resulting in limited virus multiplication which is insufficient to stimulate a detectable primary humoral immune response. PMID:8203118

  3. 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. PMID:27174088

  4. Influenza Virus Aerosols in the Air and Their Infectiousness

    PubMed Central

    2014-01-01

    Influenza is one of the most contagious and rapidly spreading infectious diseases and an important global cause of hospital admissions and mortality. There are some amounts of the virus in the air constantly. These amounts is generally not enough to cause disease in people, due to infection prevention by healthy immune systems. However, at a higher concentration of the airborne virus, the risk of human infection increases dramatically. Early detection of the threshold virus concentration is essential for prevention of the spread of influenza infection. This review discusses different approaches for measuring the amount of influenza A virus particles in the air and assessing their infectiousness. Here we also discuss the data describing the relationship between the influenza virus subtypes and virus air transmission, and distribution of viral particles in aerosol drops of different sizes. PMID:25197278

  5. Antiviral Protein of Momordica charantia L. Inhibits Different Subtypes of Influenza A

    PubMed Central

    Pongthanapisith, Viroj; Ikuta, Kazuyoshi; Puthavathana, Pilaipan; Leelamanit, Wichet

    2013-01-01

    The new antiviral activity of the protein extracted from Momordica charantia was determined with different subtypes of influenza A. The protein was purified from the seed of M. charantia using an anion exchanger and a Fast Protein Liquid Chromatography (FPLC) system. At the concentration of 1.401 mg/mL, the protein did not exhibit cytotoxicity in Madin-Darby canine kidney cells (MDCK) but inhibited 1 × 105 FFU influenza A/PR/8/34 H1N1 virus at 56.50%, 65.72%, and 100% inhibition by the protein treated before the virus (pretreated), the protein treated alongside with the virus (simultaneously treated), and the protein treated after the virus (posttreated) during incubation, respectively. Using 5, 25, and 100 TCID50 of influenza A/New Caledonia/20/99 H1N1, A/Fujian/411/01 H3N2 and A/Thailand/1(KAN-1)/2004 H5N1, the IC50 was calculated to be 100, 150, and 200; 75, 175, and 300; and 40, 75, and 200 μg/mL, respectively. Our present finding indicated that the plant protein inhibited not only H1N1 and H3N2 but also H5N1 subtype. As a result of the broad spectrum of its antiviral activity, this edible plant can be developed as an effective therapeutic agent against various and even new emerging subtypes of influenza A. PMID:23935676

  6. New World Bats Harbor Diverse Influenza A Viruses

    PubMed Central

    Tong, Suxiang; Zhu, Xueyong; Li, Yan; Shi, Mang; Zhang, Jing; Bourgeois, Melissa; Yang, Hua; Chen, Xianfeng; Recuenco, Sergio; Gomez, Jorge; Chen, Li-Mei; Johnson, Adam; Tao, Ying; Dreyfus, Cyrille; Yu, Wenli; McBride, Ryan; Carney, Paul J.; Gilbert, Amy T.; Chang, Jessie; Guo, Zhu; Davis, Charles T.; Paulson, James C.; Stevens, James; Rupprecht, Charles E.; Holmes, Edward C.; Wilson, Ian A.; Donis, Ruben O.

    2013-01-01

    Aquatic birds harbor diverse influenza A viruses and are a major viral reservoir in nature. The recent discovery of influenza viruses of a new H17N10 subtype in Central American fruit bats suggests that other New World species may similarly carry divergent influenza viruses. Using consensus degenerate RT-PCR, we identified a novel influenza A virus, designated as H18N11, in a flat-faced fruit bat (Artibeus planirostris) from Peru. Serologic studies with the recombinant H18 protein indicated that several Peruvian bat species were infected by this virus. Phylogenetic analyses demonstrate that, in some gene segments, New World bats harbor more influenza virus genetic diversity than all other mammalian and avian species combined, indicative of a long-standing host-virus association. Structural and functional analyses of the hemagglutinin and neuraminidase indicate that sialic acid is not a ligand for virus attachment nor a substrate for release, suggesting a unique mode of influenza A virus attachment and activation of membrane fusion for entry into host cells. Taken together, these findings indicate that bats constitute a potentially important and likely ancient reservoir for a diverse pool of influenza viruses. PMID:24130481

  7. TMPRSS2 Independency for Haemagglutinin Cleavage In Vivo Differentiates Influenza B Virus from Influenza A Virus.

    PubMed

    Sakai, Kouji; Ami, Yasushi; Nakajima, Noriko; Nakajima, Katsuhiro; Kitazawa, Minori; Anraku, Masaki; Takayama, Ikuyo; Sangsriratanakul, Natthanan; Komura, Miyuki; Sato, Yuko; Asanuma, Hideki; Takashita, Emi; Komase, Katsuhiro; Takehara, Kazuaki; Tashiro, Masato; Hasegawa, Hideki; Odagiri, Takato; Takeda, Makoto

    2016-01-01

    Influenza A and B viruses show clear differences in their host specificity and pandemic potential. Recent studies have revealed that the host protease TMPRSS2 plays an essential role for proteolytic activation of H1, H3, and H7 subtype strains of influenza A virus (IAV) in vivo. IAV possessing a monobasic cleavage site in the haemagglutinin (HA) protein replicates poorly in TMPRSS2 knockout mice owing to insufficient HA cleavage. In the present study, human isolates of influenza B virus (IBV) strains and a mouse-adapted IBV strain were analysed. The data showed that IBV successfully underwent HA cleavage in TMPRSS2 knockout mice, and that the mouse-adapted strain was fully pathogenic to these mice. The present data demonstrate a clear difference between IAV and IBV in their molecular mechanisms for spreading in vivo. PMID:27389476

  8. TMPRSS2 Independency for Haemagglutinin Cleavage In Vivo Differentiates Influenza B Virus from Influenza A Virus

    PubMed Central

    Sakai, Kouji; Ami, Yasushi; Nakajima, Noriko; Nakajima, Katsuhiro; Kitazawa, Minori; Anraku, Masaki; Takayama, Ikuyo; Sangsriratanakul, Natthanan; Komura, Miyuki; Sato, Yuko; Asanuma, Hideki; Takashita, Emi; Komase, Katsuhiro; Takehara, Kazuaki; Tashiro, Masato; Hasegawa, Hideki; Odagiri, Takato; Takeda, Makoto

    2016-01-01

    Influenza A and B viruses show clear differences in their host specificity and pandemic potential. Recent studies have revealed that the host protease TMPRSS2 plays an essential role for proteolytic activation of H1, H3, and H7 subtype strains of influenza A virus (IAV) in vivo. IAV possessing a monobasic cleavage site in the haemagglutinin (HA) protein replicates poorly in TMPRSS2 knockout mice owing to insufficient HA cleavage. In the present study, human isolates of influenza B virus (IBV) strains and a mouse-adapted IBV strain were analysed. The data showed that IBV successfully underwent HA cleavage in TMPRSS2 knockout mice, and that the mouse-adapted strain was fully pathogenic to these mice. The present data demonstrate a clear difference between IAV and IBV in their molecular mechanisms for spreading in vivo. PMID:27389476

  9. Novel vaccines against influenza viruses

    PubMed Central

    Kang, Sang-Moo; Song, Jae-Min; Compans, Richard W.

    2011-01-01

    Killed and live attenuated influenza virus vaccines are effective in preventing and curbing the spread of influenza epidemics when the strains present in the vaccines are closely matched with the predicted epidemic strains. These vaccines are primarily targeted to induce immunity to the variable major target antigen, hemagglutinin (HA) of influenza virus. However, current vaccines are not effective in preventing the emergence of new pandemic or highly virulent viruses. New approaches are being investigated to develop universal influenza virus vaccines as well as to apply more effective vaccine delivery methods. Conserved vaccine targets including the influenza M2 ion channel protein and HA stalk domains are being developed using recombinant technologies to improve the level of cross protection. In addition, recent studies provide evidence that vaccine supplements can provide avenues to further improve current vaccination. PMID:21968298

  10. Efficacy of intranasal administration of a truncated NS1 modified live influenza virus vaccine in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the U.S., despite available swine influenza virus (SIV) vaccines, multiple influenza subtypes as well as antigenic and genetic variants within subtypes continue to circulate in the swine population. One of the challenges to control and eliminate SIV is that the currently used inactivated influenz...

  11. Emergence of influenza A viruses.

    PubMed Central

    Webby, R J; Webster, R G

    2001-01-01

    Pandemic influenza in humans is a zoonotic disease caused by the transfer of influenza A viruses or virus gene segments from animal reservoirs. Influenza A viruses have been isolated from avian and mammalian hosts, although the primary reservoirs are the aquatic bird populations of the world. In the aquatic birds, influenza is asymptomatic, and the viruses are in evolutionary stasis. The aquatic bird viruses do not replicate well in humans, and these viruses need to reassort or adapt in an intermediate host before they emerge in human populations. Pigs can serve as a host for avian and human viruses and are logical candidates for the role of intermediate host. The transmission of avian H5N1 and H9N2 viruses directly to humans during the late 1990s showed that land-based poultry also can serve between aquatic birds and humans as intermediate hosts of influenza viruses. That these transmission events took place in Hong Kong and China adds further support to the hypothesis that Asia is an epicentre for influenza and stresses the importance of surveillance of pigs and live-bird markets in this area. PMID:11779380

  12. Variant (Swine Origin) Influenza Viruses in Humans

    MedlinePlus

    ... What's this? Submit Button Past Newsletters Variant Influenza Viruses: Background and CDC Risk Assessment and Reporting Language: ... Background CDC Assessment Reporting Background On Variant Influenza Viruses Swine flu viruses do not normally infect humans. ...

  13. A VLP Vaccine Induces Broad-Spectrum Cross-Protective Antibody Immunity against H5N1 and H1N1 Subtypes of Influenza A Virus

    PubMed Central

    Wu, Chia-Ying; Yeh, Yi-Chun; Chan, Jia-Tsrong; Yang, Yu-Chih; Yang, Ji-Rong; Liu, Ming-Tsan; Wu, Ho-Sheng; Hsiao, Pei-Wen

    2012-01-01

    The recent threats of influenza epidemics and pandemics have prioritized the development of a universal vaccine that offers protection against a wider variety of influenza infections. Here, we demonstrate a genetically modified virus-like particle (VLP) vaccine, referred to as H5M2eN1-VLP, that increased the antigenic content of NA and induced rapid recall of antibody against HA2 after viral infection. As a result, H5M2eN1-VLP vaccination elicited a broad humoral immune response against multiple viral proteins and caused significant protection against homologous RG-14 (H5N1) and heterologous A/California/07/2009 H1N1 (CA/07) and A/PR/8/34 H1N1 (PR8) viral lethal challenges. Moreover, the N1-VLP (lacking HA) induced production of a strong NA antibody that also conferred significant cross protection against H5N1 and heterologous CA/07 but not PR8, suggesting the protection against N1-serotyped viruses can be extended from avian-origin to CA/07 strain isolated in humans, but not to evolutionally distant strains of human-derived. By comparative vaccine study of an HA-based VLP (H5N1-VLP) and NA-based VLPs, we found that H5N1-VLP vaccination induced specific and strong protective antibodies against the HA1 subunit of H5, thus restricting the breadth of cross-protection. In summary, we present a feasible example of direction of VLP vaccine immunity toward NA and HA2, which resulted in cross protection against both seasonal and pandemic influenza strains, that could form the basis for future design of a better universal vaccine. PMID:22879951

  14. New aspects of influenza viruses.

    PubMed Central

    Shaw, M W; Arden, N H; Maassab, H F

    1992-01-01

    Influenza virus infections continue to cause substantial morbidity and mortality with a worldwide social and economic impact. The past five years have seen dramatic advances in our understanding of viral replication, evolution, and antigenic variation. Genetic analyses have clarified relationships between human and animal influenza virus strains, demonstrating the potential for the appearance of new pandemic reassortants as hemagglutinin and neuraminidase genes are exchanged in an intermediate host. Clinical trials of candidate live attenuated influenza virus vaccines have shown the cold-adapted reassortants to be a promising alternative to the currently available inactivated virus preparations. Modern molecular techniques have allowed serious consideration of new approaches to the development of antiviral agents and vaccines as the functions of the viral genes and proteins are further elucidated. The development of techniques whereby the genes of influenza viruses can be specifically altered to investigate those functions will undoubtedly accelerate the pace at which our knowledge expands. PMID:1310439

  15. Avian influenza virus RNA extraction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficient extraction and purification of viral RNA is critical for down-stream molecular applications whether it is the sensitive and specific detection of virus in clinical samples, virus gene cloning and expression, or quantification of avian influenza (AI) virus by molecular methods from expe...

  16. Modified live virus vaccine induces a distinct immune response profile compared to inactivated influenza A virus vaccines in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic and antigenic diversity within H1 influenza A virus (IAV) subtypes circulating in swine is increasing. The need for cross-protective influenza vaccines in swine is necessary as the virus becomes more diverse. This study compared the humoral and cell-mediated immune response of modified live ...

  17. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral.

    PubMed

    Smith, Claire M; Scott, Paul D; O'Callaghan, Christopher; Easton, Andrew J; Dimmock, Nigel J

    2016-01-01

    Defective interfering (DI) viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8) was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1); it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral. PMID:27556481

  18. A Defective Interfering Influenza RNA Inhibits Infectious Influenza Virus Replication in Human Respiratory Tract Cells: A Potential New Human Antiviral

    PubMed Central

    Smith, Claire M.; Scott, Paul D.; O’Callaghan, Christopher; Easton, Andrew J.; Dimmock, Nigel J.

    2016-01-01

    Defective interfering (DI) viruses arise during the replication of influenza A virus and contain a non-infective version of the genome that is able to interfere with the production of infectious virus. In this study we hypothesise that a cloned DI influenza A virus RNA may prevent infection of human respiratory epithelial cells with infection by influenza A. The DI RNA (244/PR8) was derived by a natural deletion process from segment 1 of influenza A/PR/8/34 (H1N1); it comprises 395 nucleotides and is packaged in the DI virion in place of a full-length genome segment 1. Given intranasally, 244/PR8 DI virus protects mice and ferrets from clinical influenza caused by a number of different influenza A subtypes and interferes with production of infectious influenza A virus in cells in culture. However, evidence that DI influenza viruses are active in cells of the human respiratory tract is lacking. Here we show that 244/PR8 DI RNA is replicated by an influenza A challenge virus in human lung diploid fibroblasts, bronchial epithelial cells, and primary nasal basal cells, and that the yield of challenge virus is significantly reduced in a dose-dependent manner indicating that DI influenza virus has potential as a human antiviral. PMID:27556481

  19. Transmission of influenza A viruses.

    PubMed

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-05-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to 'novel' viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  20. Transmission of Influenza A Viruses

    PubMed Central

    Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763

  1. Ecology of avian influenza virus in birds.

    PubMed

    Causey, Douglas; Edwards, Scott V

    2008-02-15

    Avian influenza A virus (an orthomyxovirus) is a zoonotic pathogen with a natural reservoir entirely in birds. The influenza virus genome is an 8-segment single-stranded RNA with high potential for in situ recombination. Two segments code for the hemagglutinin (H) and neuraminidase (N) antigens used for host-cell entry. At present, 16 H and 9 N subtypes are known, for a total of 144 possible different influenza subtypes, each with potentially different host susceptibility. With >10,000 species of birds found in nearly every terrestrial and aquatic habitat, there are few places on earth where birds cannot be found. The avian immune system differs from that of humans in several important features, including asynchronous B and T lymphocyte systems and a polymorphic multigene immune complex, but little is known about the immunogenetics of pathogenic response. Postbreeding dispersal and migration and a naturally high degree of environmental vagility mean that wild birds have the potential to be vectors that transmit highly pathogenic variants great distances from the original sources of infection. PMID:18269325

  2. Influenza virus hemagglutinin stalk-based antibodies and vaccines

    PubMed Central

    Krammer, Florian; Palese, Peter

    2013-01-01

    Antibodies against the conserved stalk domain of the hemagglutinin are currently being discussed as promising therapeutic tools against influenza virus infections. Due to the conservation of the stalk domain these antibodies are able to broadly neutralize a wide spectrum of influenza virus strains and subtypes. Broadly protective vaccine candidates based on the epitopes of these antibodies, e.g. chimeric and headless hemagglutinin structures, are currently under development and show promising results in animals models. These candidates could be developed into universal influenza virus vaccines that protect from infection with drifted seasonal as well as novel pandemic influenza virus strains therefore obviating the need for annual vaccination, and enhancing our pandemic preparedness. PMID:23978327

  3. Analysis of H7 avian influenza viruses by antigenic cartography and correlation to protection by vaccination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The H7 hemagglutinin subtype one of the most common subtypes of avian influenza virus (AIV) in poultry world wide and since it has the potential to become highly pathogenic it is among the priority subtypes for vaccination. Selection of the optimal vaccine seed strains may now be aided by antigenic...

  4. Household Transmission of Influenza Virus.

    PubMed

    Tsang, Tim K; Lau, Lincoln L H; Cauchemez, Simon; Cowling, Benjamin J

    2016-02-01

    Human influenza viruses cause regular epidemics and occasional pandemics with a substantial public health burden. Household transmission studies have provided valuable information on the dynamics of influenza transmission. We reviewed published studies and found that once one household member is infected with influenza, the risk of infection in a household contact can be up to 38%, and the delay between onset in index and secondary cases is around 3 days. Younger age was associated with higher susceptibility. In the future, household transmission studies will provide information on transmission dynamics, including the correlation of virus shedding and symptoms with transmission, and the correlation of new measures of immunity with protection against infection. PMID:26612500

  5. Mucosal correlates of cross-protection for live-attenuated influenza virus vaccines in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Controlling swine influenza A virus (IAV) has become increasingly difficult with the emergence of novel reassorted strains and introduction of human seasonal IAV into pigs. In North American swine there are 6 antigenically distinct H1 subtypes currently circulating. Live-attenuated influenza virus (...

  6. Susceptibility of avian species to north american H13 low pathogenic avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gulls are widely recognized reservoirs for low pathogenic avian influenza (LPAI) viruses; however, the subtypes maintained in these populations and/or the transmission mechanisms involved are poorly understood. Although, a wide diversity of influenza viruses have been isolated from gulls, two hemag...

  7. Enhanced Pneumonia With Pandemic 2009 A/H1N1 Swine Influenza Virus in Pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. Swine influenza A viruses (SIV) in the major swine producing regions of North America consist of multiple subtypes of endemic H1N1, H1N2, and H3N2 derived from swine, avian and human influenza viruses with a triple reassortant internal gene (TRIG) constellation (1). Genetic drift and r...

  8. Cloned Defective Interfering Influenza RNA and a Possible Pan-Specific Treatment of Respiratory Virus Diseases

    PubMed Central

    Dimmock, Nigel J.; Easton, Andrew J.

    2015-01-01

    Defective interfering (DI) genomes are characterised by their ability to interfere with the replication of the virus from which they were derived, and other genetically compatible viruses. DI genomes are synthesized by nearly all known viruses and represent a vast natural reservoir of antivirals that can potentially be exploited for use in the clinic. This review describes the application of DI virus to protect from virus-associated diseases in vivo using as an example a highly active cloned influenza A DI genome and virus that protects broadly in preclinical trials against different subtypes of influenza A and against non-influenza A respiratory viruses. This influenza A-derived DI genome protects by two totally different mechanisms: molecular interference with influenza A replication and by stimulating innate immunity that acts against non-influenza A viruses. The review considers what is needed to develop DI genomes to the point of entry into clinical trials. PMID:26184282

  9. Influenza virus antigenicity and broadly neutralizing epitopes

    PubMed Central

    Air, Gillian M.

    2015-01-01

    A vaccine formulation that would be effective against all strains of influenza virus has long been a goal of vaccine developers, but antibodies after infection or vaccination were seen to be strain specific and there was little evidence of cross-reactive antibodies that neutralized across subtypes. Recently a number of broadly neutralizing monoclonal antibodies have been characterized. This review describes the different classes of broadly neutralizing antibodies and discusses the potential of their therapeutic use or for design of immunogens that induce a high proportion of broadly neutralizing antibodies. PMID:25846699

  10. Influenza A virus in pigs – protection, provocation and predisposition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Endemic strains of influenza A virus (IAV) in North America pigs consist of the subtypes H1N1, H1N2, and H3N2. These circulating strains contain the triple reassortant internal gene (TRIG) cassette resulting from incorporation of genes from swine, avian, and human IAV's. Genetic drift and reassortme...

  11. Influenza A virus and secondary bacterial infection in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus (IAV) infection alone causes significant disease characterized by respiratory distress and poor growth in pigs. Endemic strains of IAV in North America pigs consist of the subtypes H1N1, H1N2, and H3N2. These circulating strains contain the triple reassortant internal gene (TRIG) c...

  12. Highly pathogenic avian influenza virus among wild birds in Mongolia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The central Asian country of Mongolia supports large populations of migratory water birds that migrate across much of Asia where highly pathogenic avian influenza (HPAI) virus subtype H5N1 is endemic. This, together with the near absence of domestic poultry, makes Mongolia an ideal location to unde...

  13. Sampling strategies and biodiversity of influenza A subtypes in wild birds.

    PubMed

    Olson, Sarah H; Parmley, Jane; Soos, Catherine; Gilbert, Martin; Latorre-Margalef, Neus; Hall, Jeffrey S; Hansbro, Phillip M; Leighton, Frederick; Munster, Vincent; Joly, Damien

    2014-01-01

    Wild aquatic birds are recognized as the natural reservoir of avian influenza A viruses (AIV), but across high and low pathogenic AIV strains, scientists have yet to rigorously identify most competent hosts for the various subtypes. We examined 11,870 GenBank records to provide a baseline inventory and insight into patterns of global AIV subtype diversity and richness. Further, we conducted an extensive literature review and communicated directly with scientists to accumulate data from 50 non-overlapping studies and over 250,000 birds to assess the status of historic sampling effort. We then built virus subtype sample-based accumulation curves to better estimate sample size targets that capture a specific percentage of virus subtype richness at seven sampling locations. Our study identifies a sampling methodology that will detect an estimated 75% of circulating virus subtypes from a targeted bird population and outlines future surveillance and research priorities that are needed to explore the influence of host and virus biodiversity on emergence and transmission. PMID:24599502

  14. Sampling strategies and biodiversity of influenza A subtypes in wild birds

    USGS Publications Warehouse

    Olson, Sarah H.; Parmley, Jane; Soos, Catherine; Gilbert, Martin; Latore-Margalef, Neus; Hall, Jeffrey S.; Hansbro, Phillip M.; Leighton, Frank; Munster, Vincent; Joly, Damien

    2014-01-01

    Wild aquatic birds are recognized as the natural reservoir of avian influenza A viruses (AIV), but across high and low pathogenic AIV strains, scientists have yet to rigorously identify most competent hosts for the various subtypes. We examined 11,870 GenBank records to provide a baseline inventory and insight into patterns of global AIV subtype diversity and richness. Further, we conducted an extensive literature review and communicated directly with scientists to accumulate data from 50 non-overlapping studies and over 250,000 birds to assess the status of historic sampling effort. We then built virus subtype sample-based accumulation curves to better estimate sample size targets that capture a specific percentage of virus subtype richness at seven sampling locations. Our study identifies a sampling methodology that will detect an estimated 75% of circulating virus subtypes from a targeted bird population and outlines future surveillance and research priorities that are needed to explore the influence of host and virus biodiversity on emergence and transmission.

  15. Avian Influenza A Virus Infections in Humans

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Submit What's this? Submit Button Past Newsletters Avian Influenza A Virus Infections in Humans Language: English Españ ...

  16. Influenza A virus among the hospitalized young children with acute respiratory infection. Is influenza A co infected with respiratory syncytial virus?

    PubMed Central

    Alavi, Seyed Mohammad; Makvandi, Manoochehr; Najafi-Fard, Saied; Alavi, Leila

    2012-01-01

    Background: Both influenza A virus (IAV) and respiratory syncytial virus (RSV) cause acute respiratory infection (ARI) in infants and young children. This study was conducted to determine Influenza A virus and its co infection with RSV among the hospitalized children with ARI. Methods: A total of 153 throat samples of the hospitalized young children aged between below one year and 5 years with the clinical signs of ARI were collected from the different hospitals in Khuzestan from June 2009 to April 2010. The samples were tested for Influenza A viruses by real time PCR. Positive IAV samples were tested for influenza A sub type H1N1 and for RSV by the nested PCR. Results: In this study, from the total 153 samples, 35 samples (22.9%) including 15 (42.8%) females and 20 (57.2%) males were positive for influenza A viruses. From the 35 positive samples for IAV, 14 were positive for swine H1N1 subtype. All the positive samples for influenza showed negative for RSV infection which revealed no coinfection with RSV. The prevalence of influenza A among age/sex groups was not significant. Conclusion: Influenza A is a prevalent viral agent isolated from young children with ARI. Influenza A subtype H1N1 was accounted for the 40 percent all laboratory-proven diagnoses of influenza in 2009. No evidence of coinfection of influenza A and RSV has been observed in the present study. PMID:24009929

  17. Nanomicroarray and Multiplex Next-Generation Sequencing for Simultaneous Identification and Characterization of Influenza Viruses

    PubMed Central

    Ragupathy, Viswanath; Liu, Jikun; Wang, Xue; Vemula, Sai Vikram; El Mubarak, Haja Sittana; Ye, Zhiping; Landry, Marie L.

    2015-01-01

    Conventional methods for detection and discrimination of influenza viruses are time consuming and labor intensive. We developed a diagnostic platform for simultaneous identification and characterization of influenza viruses that uses a combination of nanomicroarray for screening and multiplex next-generation sequencing (NGS) assays for laboratory confirmation. The nanomicroarray was developed to target hemagglutinin, neuraminidase, and matrix genes to identify influenza A and B viruses. PCR amplicons synthesized by using an adapted universal primer for all 8 gene segments of 9 influenza A subtypes were detected in the nanomicroarray and confirmed by the NGS assays. This platform can simultaneously detect and differentiate multiple influenza A subtypes in a single sample. Use of these methods as part of a new diagnostic algorithm for detection and confirmation of influenza infections may provide ongoing public health benefits by assisting with future epidemiologic studies and improving preparedness for potential influenza pandemics. PMID:25694248

  18. Influenza in Migratory Birds and Evidence of Limited Intercontinental Virus Exchange

    PubMed Central

    Krauss, Scott; Obert, Caroline A; Franks, John; Walker, David; Jones, Kelly; Seiler, Patrick; Niles, Larry; Pryor, S. Paul; Obenauer, John C; Naeve, Clayton W; Widjaja, Linda; Webby, Richard J; Webster, Robert G

    2007-01-01

    Migratory waterfowl of the world are the natural reservoirs of influenza viruses of all known subtypes. However, it is unknown whether these waterfowl perpetuate highly pathogenic (HP) H5 and H7 avian influenza viruses. Here we report influenza virus surveillance from 2001 to 2006 in wild ducks in Alberta, Canada, and in shorebirds and gulls at Delaware Bay (New Jersey), United States, and examine the frequency of exchange of influenza viruses between the Eurasian and American virus clades, or superfamilies. Influenza viruses belonging to each of the subtypes H1 through H13 and N1 through N9 were detected in these waterfowl, but H14 and H15 were not found. Viruses of the HP Asian H5N1 subtypes were not detected, and serologic studies in adult mallard ducks provided no evidence of their circulation. The recently described H16 subtype of influenza viruses was detected in American shorebirds and gulls but not in ducks. We also found an unusual cluster of H7N3 influenza viruses in shorebirds and gulls that was able to replicate well in chickens and kill chicken embryos. Genetic analysis of 6,767 avian influenza gene segments and 248 complete avian influenza viruses supported the notion that the exchange of entire influenza viruses between the Eurasian and American clades does not occur frequently. Overall, the available evidence does not support the perpetuation of HP H5N1 influenza in migratory birds and suggests that the introduction of HP Asian H5N1 to the Americas by migratory birds is likely to be a rare event. PMID:17997603

  19. Swine Influenza Virus: Emerging Understandings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction: In March-April 2009, a novel pandemic H1N1 emerged in the human population in North America [1]. The gene constellation of the emerging virus was demonstrated to be a combination of genes from swine influenza A viruses (SIV) of North American and Eurasian lineages that had never before...

  20. Adaptation of pandemic H2N2 influenza A viruses in humans.

    PubMed

    Joseph, Udayan; Linster, Martin; Suzuki, Yuka; Krauss, Scott; Halpin, Rebecca A; Vijaykrishna, Dhanasekaran; Fabrizio, Thomas P; Bestebroer, Theo M; Maurer-Stroh, Sebastian; Webby, Richard J; Wentworth, David E; Fouchier, Ron A M; Bahl, Justin; Smith, Gavin J D

    2015-02-01

    The 1957 A/H2N2 influenza virus caused an estimated 2 million fatalities during the pandemic. Since viruses of the H2 subtype continue to infect avian species and pigs, the threat of reintroduction into humans remains. To determine factors involved in the zoonotic origin of the 1957 pandemic, we performed analyses on genetic sequences of 175 newly sequenced human and avian H2N2 virus isolates and all publicly available influenza virus genomes. PMID:25505070

  1. Highly pathogenic avian influenza virus (H5N1) in experimentally infected adult mute swans.

    PubMed

    Kalthoff, Donata; Breithaupt, Angele; Teifke, Jens P; Globig, Anja; Harder, Timm; Mettenleiter, Thomas C; Beer, Martin

    2008-08-01

    Adult, healthy mute swans were experimentally infected with highly pathogenic avian influenza virus A/Cygnus cygnus/Germany/R65/2006 subtype H5N1. Immunologically naive birds died, whereas animals with preexisting, naturally acquired avian influenza virus-specific antibodies became infected asymptomatically and shed virus. Adult mute swans are highly susceptible, excrete virus, and can be clinically protected by preexposure immunity. PMID:18680652

  2. Influenza A strain-dependent pathogenesis in fatal H1N1 and H5N1 subtype infections of mice.

    PubMed

    Garigliany, Mutien Marie; Habyarimana, Adélite; Lambrecht, Bénédicte; Van de Paar, Els; Cornet, Anne; van den Berg, Thierry; Desmecht, Daniel

    2010-04-01

    To determine if fatal infections caused by different highly virulent influenza A viruses share the same pathogenesis, we compared 2 different influenza A virus subtypes, H1N1 and H5N1. The subtypes, which had shown no pathogenicity in laboratory mice, were forced to evolve by serial passaging. Although both adapted viruses evoked diffuse alveolar damage and showed a similar 50% mouse lethal dose and the same peak lung concentration, each had a distinct pathologic signature and caused a different course of acute respiratory distress syndrome. In the absence of any virus labeling, a histologist could readily distinguish infections caused by these 2 viruses. The different histologic features described in this study here refute the hypothesis of a single, universal cytokine storm underlying all fatal influenza diseases. Research is thus crucially needed to identify sets of virulence markers and to examine whether treatment should be tailored to the influenza virus pathotype. PMID:20350372

  3. Influenza A Strain-Dependent Pathogenesis in Fatal H1N1 and H5N1 Subtype Infections of Mice

    PubMed Central

    Garigliany, Mutien-Marie; Habyarimana, Adélite; Lambrecht, Bénédicte; Van de Paar, Els; Cornet, Anne; van den Berg, Thierry

    2010-01-01

    To determine if fatal infections caused by different highly virulent influenza A viruses share the same pathogenesis, we compared 2 different influenza A virus subtypes, H1N1 and H5N1. The subtypes, which had shown no pathogenicity in laboratory mice, were forced to evolve by serial passaging. Although both adapted viruses evoked diffuse alveolar damage and showed a similar 50% mouse lethal dose and the same peak lung concentration, each had a distinct pathologic signature and caused a different course of acute respiratory distress syndrome. In the absence of any virus labeling, a histologist could readily distinguish infections caused by these 2 viruses. The different histologic features described in this study here refute the hypothesis of a single, universal cytokine storm underlying all fatal influenza diseases. Research is thus crucially needed to identify sets of virulence markers and to examine whether treatment should be tailored to the influenza virus pathotype. PMID:20350372

  4. Serologic evidence of influenza A(H1N1)pdm09 virus in northern sea otters

    USGS Publications Warehouse

    Li, Zhu-Nan; Ip, Hon S.; Frost, Jessica F.; White, C. LeAnn; Murray, Michael J.; Carney, Paul J.; Sun, Xiang-Jie; Stevens, James; Levine, Min Z.; Katz, Jacqueline M.

    2014-01-01

    Sporadic epizootics of pneumonia among marine mammals have been associated with multiple animal-origin influenza A virus subtypes (1–6); seals are the only known nonhuman host for influenza B viruses (7). Recently, we reported serologic evidence of influenza A virus infection in free-ranging northern sea otters (Enhydra lutris kenyoni) captured off the coast of Washington, USA, in August 2011 (8). To investigate further which influenza A virus subtype infected these otters, we tested serum samples from these otters by ELISA for antibody-binding activity against 12 recombinant hemagglutinins (rHAs) from 7 influenza A hemagglutinin (HA) subtypes and 2 lineages of influenza B virus (Technical Appendix Table 1). Estimated ages for the otters were 2–19 years (Technical Appendix Table 2); we also tested archived serum samples from sea otters of similar ages collected from a study conducted during 2001–2002 along the Washington coast (9).

  5. Influenza A virus (H3N8) in dogs with respiratory disease, Florida.

    PubMed

    Payungporn, Sunchai; Crawford, P Cynda; Kouo, Theodore S; Chen, Li-mei; Pompey, Justine; Castleman, William L; Dubovi, Edward J; Katz, Jacqueline M; Donis, Ruben O

    2008-06-01

    In 2004, canine influenza virus subtype H3N8 emerged in greyhounds in the United States. Subsequent serologic evidence indicated virus circulation in dog breeds other than greyhounds, but the virus had not been isolated from affected animals. In 2005, we conducted virologic investigation of 7 nongreyhound dogs that died from respiratory disease in Florida and isolated influenza subtype H3N8 virus. Antigenic and genetic analysis of A/canine/Jacksonville/2005 (H3N8) and A/canine/Miami/2005 (H3N8) found similarity to earlier isolates from greyhounds, which indicates that canine influenza viruses are not restricted to greyhounds. The hemagglutinin contained 5 conserved amino acid differences that distinguish canine from equine lineages. The antigenic homogeneity of the canine viruses suggests that measurable antigenic drift has not yet occurred. Continued surveillance and antigenic analyses should monitor possible emergence of antigenic variants of canine influenza virus. PMID:18507900

  6. Development and bench validation of real time RT-PCR protocols for rapid detection of the subtypes H6, H9 and H11 of avian influenza viruses in experimental samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Real time RT-PCR (RRT-PCR) is commonly used for the rapid detection of avian influenza viruses (AIV) from clinical samples. Samples are typically screened for type A influenza by targeting the matrix gene, and then positive samples are further tested for hemagglutinin (HA) and neuraminidase (NA) su...

  7. The pig as a mixing vessel for influenza viruses: Human and veterinary implications

    PubMed Central

    Ma, Wenjun; Kahn, Robert E; Richt, Juergen A

    2009-01-01

    Influenza A viruses are highly infectious respiratory pathogens that can infect many species. Birds are the reservoir for all known influenza A subtypes; and novel influenza viruses can emerge from birds and infect mammalian species including humans. Because swine are susceptible to infection with both avian and human influenza viruses, novel reassortant influenza viruses can be generated in this mammalian species by reassortment of influenza viral segments leading to the “mixing vessel” theory. There is no direct evidence that the reassortment events culminating in the 1918, 1957 or 1968 pandemic influenza viruses originated from pigs. Genetic reassortment among avian, human and/or swine influenza virus gene segments has occurred in pigs and some novel reassortant swine viruses have been transmitted to humans. Notably, novel reassortant H2N3 influenza viruses isolated from the US pigs, most likely infected with avian influenza viruses through surface water collected in ponds for cleaning barns and watering animals, had a similar genetic make-up to early isolates (1957) of the H2N2 human pandemic. These novel H2N3 swine viruses were able to cause disease in swine and mice and were infectious and highly transmissible in swine and ferrets without prior adaptation. The preceding example shows that pigs could transmit novel viruses from an avian reservoir to other mammalian species. Importantly, H2 viruses pose a substantial risk to humans because they have been absent from mammalian species since 1968 and people born after 1968 have little preexisting immunity to the H2 subtype. It is difficult to predict which virus will cause the next human pandemic and when that pandemic might begin. Importantly, the establishment and spread of a reassorted mammalian-adapted virus from pigs to humans could happen anywhere in the world. Therefore, both human and veterinary research needs to give more attention to potential cross-species transmission capacity of influenza A

  8. Experimental Evaluation of a Swine Influenza Virus Isolated from a County Fair Outbreak in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1998, 3 predominant swine influenza virus (SIV) subtypes have circulated in US swine, H1N1, H1N2, and H3N2. Distinct antigenic and genetic clusters have been demonstrated within the H1 and H3 SIV subtypes (1, 2). In August 2007, pigs and people became clinically affected by an influenza-like i...

  9. A live attenuated cold adapted influenza A H7N3 virus vaccine provides protection against homologous and heterologous H7 viruses in mice and ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The appearance of human infections caused by avian influenza A H7 subtype viruses underscore their pandemic potential and the need to develop vaccines to protect humans from viruses of this subtype. A live attenuated H7N3 virus vaccine was generated by reverse genetics using the HA and NA genes of ...

  10. Novel hemagglutinin-based influenza virus inhibitors

    PubMed Central

    Shen, Xintian; Zhang, Xuanxuan

    2013-01-01

    Influenza virus has caused seasonal epidemics and worldwide pandemics, which caused tremendous loss of human lives and socioeconomics. Nowadays, only two classes of anti-influenza drugs, M2 ion channel inhibitors and neuraminidase inhibitors respectively, are used for prophylaxis and treatment of influenza virus infection. Unfortunately, influenza virus strains resistant to one or all of those drugs emerge frequently. Hemagglutinin (HA), the glycoprotein in influenza virus envelope, plays a critical role in viral binding, fusion and entry processes. Therefore, HA is a promising target for developing anti-influenza drugs, which block the initial entry step of viral life cycle. Here we reviewed recent understanding of conformational changes of HA in protein folding and fusion processes, and the discovery of HA-based influenza entry inhibitors, which may provide more choices for preventing and controlling potential pandemics caused by multi-resistant influenza viruses. PMID:23977436

  11. A practical approach to genetic screening for influenza virus variants.

    PubMed Central

    Zou, S

    1997-01-01

    This report describes a quick genetic approach to the screening of influenza virus variants. Multiplex reverse transcription (MRT) and multiplex PCR (MPCR) were used to amplify and differentiate the hemagglutinin (HA) genes of different types and subtypes of influenza viruses. Heteroduplex mobility assay (HMA) was then used to differentiate strains within the same type and subtype. Three primers complementary to the consensus 3' termini of viral genomic RNA segments of human influenza virus types A, B, and C were used in a single MRT reaction to prime the synthesis of cDNA of all the viral genome segments. The cDNA was then amplified in an MPCR containing primers for the HA genes of the H1 and H3 subtypes of type A, the HA gene of type B, and the counterpart of type C virus. Amplicons of the different types and subtypes differ in size, thus allowing typing and subtyping. The regions amplified cover most of the HA1 portion of the HA genes and therefore amplicons of variants identified by the described HMA can be sequenced directly. In the HMA, the amplicon of an individual strain was mixed with that of a reference strain and heteroduplexes derived from mismatches migrated more slowly than homoduplexes of the same size in electrophoresis, with the mobility shift pattern indicating the divergence of amplicons. The whole process from viral RNA extraction to HMA can be completed within 2 days and thus provides a quick screening before further analysis by hemagglutination inhibition testing and sequencing. In addition, all segments of the viral genome can be amplified from a single MRT reaction, which can yield valuable sources of products for future genetic analyses. This method should facilitate genetic screening and characterization of influenza virus variants. PMID:9316919

  12. Protection against H1N1 influenza challenge by a DNA vaccine expressing H3/H1 subtype hemagglutinin combined with MHC class II-restricted epitopes

    PubMed Central

    2010-01-01

    Background Multiple subtypes of avian influenza viruses have crossed the species barrier to infect humans and have the potential to cause a pandemic. Therefore, new influenza vaccines to prevent the co-existence of multiple subtypes within a host and cross-species transmission of influenza are urgently needed. Methods Here we report a multi-epitope DNA vaccine targeted towards multiple subtypes of the influenza virus. The protective hemagglutinin (HA) antigens from H5/H7/H9 subtypes were screened for MHC II class-restricted epitopes overlapping with predicted B cell epitopes. We then constructed a DNA plasmid vaccine, pV-H3-EHA-H1, based on HA antigens from human influenza H3/H1 subtypes combined with the H5/H7/H9 subtype Th/B epitope box. Results Epitope-specific IFN-γ ELISpot responses were significantly higher in the multi-epitope DNA group than in other vaccine and control groups (P < 0.05). The multi-epitope group significantly enhanced Th2 cell responses as determined by cytokine assays. The survival rate of mice given the multi-epitope vaccine was the highest among the vaccine groups, but it was not significantly different compared to those given single antigen expressing pV-H1HA1 vaccine and dual antigen expressing pV-H3-H1 vaccine (P > 0.05). No measurable virus titers were detected in the lungs of the multi-epitope immunized group. The unique multi-epitope DNA vaccine enhanced virus-specific antibody and cellular immunity as well as conferred complete protection against lethal challenge with A/New Caledonia/20/99 (H1N1) influenza strain in mice. Conclusions This approach may be a promising strategy for developing a universal influenza vaccine to prevent multiple subtypes of influenza virus and to induce long-term protective immune against cross-species transmission. PMID:21134292

  13. Initiation and regulation of immune responses to immunization with whole inactivated vaccines prepared from two genetically and antigenically distinct lineages of Egyptian influenza A virus subtype H5N1.

    PubMed

    Samy, Ahmed; El-Enbaawy, Mona I; El-Sanousi, Ahmed A; Nasef, Soad A; Hikono, Hirokazu; Saito, Takehiko

    2016-10-01

    Following the introduction of highly pathogenic avian influenza (HPAI) virus subtype H5N1, the Egyptian government implemented a massive poultry vaccination campaign as the cornerstone of its policies to control the virus. The efficacy of vaccination has been evaluated primarily by measuring titers of antibodies inhibiting the hemagglutinating activity of the viral hemagglutinin (HA). However, other aspects of the host response remain poorly understood. In the present study, in addition to hemagglutination inhibition (HI) titers, cytokine profiles were examined and IFNγ concentrations were measured in vivo after immunization with a whole inactivated virus (WIV) prepared from a classical strain of clade 2.2.1.2 (C121) and an antigenic drift variant of clade 2.2.1.1 (V1063). The results revealed an earlier response and higher HI titers and IFNγ levels in sera from chickens immunized with C121, accompanied by significantly higher expression of IL8, IL10, and IL18 in the spleen and IL6 and IL10 in the bursa, compared to those immunized with V1063. Furthermore, stimulation of the HD11 cell line with C121 induced gradual upregulation of pro-inflammatory cytokines, which was observed at 24 hours post-inoculation (hpi), and became more pronounced at 48 and 72 hpi, accompanied by upregulation of IFNα. Conversely, V1063 induced very early transient higher expression of pro-inflammatory cytokines at 3 and 6 hpi accompanied by upregulation of IL10, which then decreased at 24, 48 and 72 hpi. In summary, our results provide evidence of a correlation between adaptive immune responses induced by WIVs and higher expression of IL10 and IL18 in addition to early induction of IFNα. These findings could be used to improve immune responses induced by WIVs. PMID:27449156

  14. Protection against multiple influenza A subtypes by vaccination with highly conserved nucleoprotein.

    PubMed

    Epstein, Suzanne L; Kong, Wing-pui; Misplon, Julia A; Lo, Chia-Yun; Tumpey, Terrence M; Xu, Ling; Nabel, Gary J

    2005-11-16

    Influenza epidemic and pandemic strains cannot be predicted with certainty. Current vaccines elicit antibodies effective against specific strains, but new strategies are urgently needed for protection against unexpected strains. DNA vaccines encoding conserved antigens protect animals against diverse subtypes, but their potency needs improvement. We tested DNA prime-recombinant adenoviral boost immunization to nucleoprotein (NP). Strong antibody and T cell responses were induced. Protection against challenge was T cell-dependent and substantially more potent than DNA vaccination alone. Importantly, vaccination protected against lethal challenge with highly pathogenic H5N1 virus. Thus, gene-based vaccination with NP may contribute to protective immunity against diverse influenza viruses through its ability to stimulate cellular immunity. PMID:16011865

  15. Selecting Viruses for the Seasonal Influenza Vaccine

    MedlinePlus

    ... which viruses are selected for use in vaccine production? The influenza viruses in the seasonal flu vaccine ... to get a good vaccine virus for vaccine production? There are a number of factors that can ...

  16. Mucosal correlates of cross-protection for live-attenuated influenza virus vaccines in pigs.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Controlling influenza A virus (IAV) in swine has become increasingly difficult with the emergence of novel reassorted strains and introduction of human seasonal IAV into pigs. In North America there are six antigenically distinct H1 subtypes currently circulating in pigs. Live-attenuated influenza v...

  17. The pathogenesis of H3N8 canine influenza virus in chickens and turkeys

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canine influenza virus (CIV) of the H3N8 subtype has emerged in dog populations throughout the U.S. where it has become endemic in kennels and animal shelters in some regions of the U.S. CIV is believed to be an equine influenza that was transmitted to and adapted to dogs. It has not previously bee...

  18. Quantifying homologous and heterologous antibody titre rises after influenza virus infection.

    PubMed

    Freeman, G; Perera, R A P M; Ngan, E; Fang, V J; Cauchemez, S; Ip, D K M; Peiris, J S M; Cowling, B J

    2016-08-01

    Most influenza virus infections are associated with mild disease. One approach to estimate the occurrence of influenza virus infections in individuals is via repeated measurement of humoral antibody titres. We used baseline and convalescent antibody titres measured by haemagglutination inhibition (HI) and viral neutralization (VN) assays against influenza A(H1N1), A(H3N2) and B viruses to investigate the characteristics of antibody rises following virologically confirmed influenza virus infections in participants in a community-based study. Multivariate models were fitted in a Bayesian framework to characterize the distribution of changes in antibody titres following influenza A virus infections. In 122 participants with PCR-confirmed influenza A virus infection, homologous antibody titres rose by geometric means of 1·2- to 10·2-fold after infection with A(H1N1), A(H3N2) and A(H1N1)pdm09. Significant cross-reactions were observed between A(H1N1)pdm09 and seasonal A(H1N1). Antibody titre rises for some subtypes and assays varied by age, receipt of oseltamivir treatment, and recent receipt of influenza vaccination. In conclusion, we provided a quantitative description of the mean and variation in rises in influenza virus antibody titres following influenza virus infection. The multivariate patterns in boosting of antibody titres following influenza virus infection could be taken into account to improve estimates of cumulative incidence of infection in seroepidemiological studies. PMID:27018720

  19. Detection of influenza C virus but not influenza D virus in Scottish respiratory samples

    PubMed Central

    Smith, Donald B.; Gaunt, Eleanor R.; Digard, Paul; Templeton, Kate; Simmonds, Peter

    2016-01-01

    Background A newly proposed genus of influenza virus (influenza D) is associated with respiratory disease in pigs and cattle. The novel virus is most closely related to human influenza C virus and can infect ferrets but infection has not been reported in humans. Objectives To ascertain if influenza D virus can be detected retrospectively in patient respiratory samples. Study design 3300 human respiratory samples from Edinburgh, Scotland, covering the period 2006–2008, were screened in pools of 10 by RT-PCR using primers capable of detecting both influenza C and D viruses. Results Influenza D was not detected in any sample. Influenza C was present in 6 samples (0.2%), compared with frequencies of 3.3% and 0.9% for influenza A and B viruses from RT-PCR testing of respiratory samples over the same period. Influenza C virus was detected in samples from individuals <2 years or >45 years old, with cases occurring throughout the year. Phylogenetic analysis of nearly complete sequences of all seven segments revealed the presence of multiple, reassortant lineages. Conclusion We were unable to detect viruses related to influenza D virus in human respiratory samples. Influenza C virus was less prevalent than influenza A and B viruses, was associated with mild disease in the young (<2 years) and old (>45 years) and comprised multiple, reassortant lineages. Inclusion of influenza C virus as part of a diagnostic testing panel for respiratory infections would be of limited additional value. PMID:26655269

  20. Antibody Recognition of a Highly Conserved Influenza Virus Epitope

    SciTech Connect

    Ekiert, Damian C.; Bhabha, Gira; Elsliger, Marc-André; Friesen, Robert H.E.; Jongeneelen, Mandy; Throsby, Mark; Goudsmit, Jaap; Wilson, Ian A.; Scripps; Crucell

    2009-05-21

    Influenza virus presents an important and persistent threat to public health worldwide, and current vaccines provide immunity to viral isolates similar to the vaccine strain. High-affinity antibodies against a conserved epitope could provide immunity to the diverse influenza subtypes and protection against future pandemic viruses. Cocrystal structures were determined at 2.2 and 2.7 angstrom resolutions for broadly neutralizing human antibody CR6261 Fab in complexes with the major surface antigen (hemagglutinin, HA) from viruses responsible for the 1918 H1N1 influenza pandemic and a recent lethal case of H5N1 avian influenza. In contrast to other structurally characterized influenza antibodies, CR6261 recognizes a highly conserved helical region in the membrane-proximal stem of HA1 and HA2. The antibody neutralizes the virus by blocking conformational rearrangements associated with membrane fusion. The CR6261 epitope identified here should accelerate the design and implementation of improved vaccines that can elicit CR6261-like antibodies, as well as antibody-based therapies for the treatment of influenza.

  1. Evolutionary Dynamics and Global Diversity of Influenza A Virus

    PubMed Central

    Rejmanek, Daniel; Hosseini, Parviez R.; Mazet, Jonna A. K.; Daszak, Peter

    2015-01-01

    ABSTRACT The increasing number of zoonotic infections caused by influenza A virus (IAV) subtypes of avian origin (e.g., H5N1 and H7N9) in recent years underscores the need to better understand the factors driving IAV evolution and diversity. To evaluate the current feasibility of global analyses to contribute to this aim, we evaluated information in the public domain to explore IAV evolutionary dynamics, including nucleotide substitution rates and selection pressures, using 14 IAV subtypes in 32 different countries over a 12-year period (2000 to 2011). Using geospatial information from 39,785 IAV strains, we examined associations between subtype diversity and socioeconomic, biodiversity, and agricultural indices. Our analyses showed that nucleotide substitution rates for 11 of the 14 evaluated subtypes tended to be higher in Asian countries, particularly in East Asia, than in Canada and the United States. Similarly, at a regional level, subtypes H5N1, H5N2, and H6N2 exhibited significantly higher substitution rates in East Asia than in North America. In contrast, the selection pressures (measured as ratios of nonsynonymous to synonymous evolutionary changes [dN/dS ratios]) acting on individual subtypes showed little geographic variation. We found that the strongest predictors for the detected subtype diversity at the country level were reporting effort (i.e., total number of strains reported) and health care spending (an indicator of economic development). Our analyses also identified major global gaps in IAV reporting (including a lack of sequences submitted from large portions of Africa and South America and a lack of geolocation information) and in broad subtype testing which, until addressed, will continue to hinder efforts to track the evolution and diversity of IAV around the world. IMPORTANCE In recent years, an increasing number of influenza A virus (IAV) subtypes, including H5N1, H7N9, and H10N8, have been detected in humans. High fatality rates have led

  2. Immunosuppression During Influenza Virus Infection

    PubMed Central

    Kantzler, G. B.; Lauteria, S. F.; Cusumano, C. L.; Lee, J. D.; Ganguly, R.; Waldman, R. H.

    1974-01-01

    The effects of a live attenuated influenza vaccine and subsequent challenge with virulent influenza virus on the delayed hypersensitivity skin test, and the in vitro response of lymphocytes were evaluated. Volunteers were skin tested before and after administration of vaccine or placebo and challenge with PPD (a purified protein derivative of Mycobacterium tuberculosis), candida, mumps, and trichophytin, and their lymphocytes were tested for [3H]thymidine uptake in response to phytohemagglutin. Of eight volunteers who showed evidence of viral replication after administration of the attenuated vaccine, four had a significant diminution in their skin test response, whereas 8 of 13 volunteers infected with virulent influenza virus showed a diminution. Of the 21 volunteers who were infected with either attenuated or virulent influenza virus, 12 showed suppression of their phytohemagglutin response. None of the volunteers who were given placebo vaccine, or who showed no evidence for viral replication after immunization or challenge, had a suppression of their skin test or phytohemagglutin responses. Although most of the infected volunteers demonstrated suppression of their T-cell function, there was no evidence of a similar suppression of B-cell function. PMID:16558116

  3. Performance of rapid SOFIA Influenza A+B test compared to Luminex x-TAG respiratory viral panel assay in the diagnosis of influenza A, B, and subtype H3.

    PubMed

    Selove, W; Rao, L V

    2016-04-01

    Influenza is an acute respiratory illness caused by influenza A or B viruses that occur in outbreaks, mainly during the winter season. Rapid laboratory diagnosis of influenza can help guide the clinical management of suspected patients effectively. Clinical sensitivities and specificities of the rapid influenza diagnostic tests have varied considerably in the literature. Most of these studies are evaluated using previously frozen or stored specimens that had previously tested positive. This study compares the performance of the rapid SOFIA Influenza A+B test to nucleic acid multiplex test x-TAG respiratory viral panel (RVP) assay in freshly collected nasal aspirates and measured simultaneously by both assays. Retrospective data from 1649 nasal aspirates (September 2014 to May 2015) collected from adults as well as from children tested simultaneously by both rapid SOFIA Influenza A+B FIA immunofluorescence (Quidel, San Diego, CA) and qualitative nucleic acid multiplex RVP assay X-TAG Luminex technology (Luminex, Austin, Texas, USA) were analyzed. Concordance, and analytical sensitivity and specificity were evaluated for influenza A, subtypes H1 and H3, and influenza B. Prevalence for influenza A by RVP was 15%, for subtype H3 it was 11.2%, and for influenza B, 2.9%. None of the aspirates were positive for influenza A subtype H1. SOFIA Influenza rapid test demonstrated good specificity and low sensitivity compared with a nucleic acid test for influenza A, subtype H3, and for influenza B. SOFIA Influenza A + B test performed well in providing a rapid diagnosis, however, confirmatory molecular testing is recommended for negative test results. Re-evaluation of test performance should be periodically carried out during outbreaks with the emergence and circulation of new influenza strains. PMID:26911275

  4. Performance of rapid SOFIA Influenza A+B test compared to Luminex x-TAG respiratory viral panel assay in the diagnosis of influenza A, B, and subtype H3

    PubMed Central

    Selove, W; Rao, L V

    2016-01-01

    Influenza is an acute respiratory illness caused by influenza A or B viruses that occur in outbreaks, mainly during the winter season. Rapid laboratory diagnosis of influenza can help guide the clinical management of suspected patients effectively. Clinical sensitivities and specificities of the rapid influenza diagnostic tests have varied considerably in the literature. Most of these studies are evaluated using previously frozen or stored specimens that had previously tested positive. This study compares the performance of the rapid SOFIA Influenza A+B test to nucleic acid multiplex test x-TAG respiratory viral panel (RVP) assay in freshly collected nasal aspirates and measured simultaneously by both assays. Retrospective data from 1649 nasal aspirates (September 2014 to May 2015) collected from adults as well as from children tested simultaneously by both rapid SOFIA Influenza A+B FIA immunofluorescence (Quidel, San Diego, CA) and qualitative nucleic acid multiplex RVP assay X-TAG Luminex technology (Luminex, Austin, Texas, USA) were analyzed. Concordance, and analytical sensitivity and specificity were evaluated for influenza A, subtypes H1 and H3, and influenza B. Prevalence for influenza A by RVP was 15%, for subtype H3 it was 11.2%, and for influenza B, 2.9%. None of the aspirates were positive for influenza A subtype H1. SOFIA Influenza rapid test demonstrated good specificity and low sensitivity compared with a nucleic acid test for influenza A, subtype H3, and for influenza B. SOFIA Influenza A + B test performed well in providing a rapid diagnosis, however, confirmatory molecular testing is recommended for negative test results. Re-evaluation of test performance should be periodically carried out during outbreaks with the emergence and circulation of new influenza strains. PMID:26911275

  5. A PCR based method for the identification of equine influenza virus from clinical samples.

    PubMed

    Oxburgh, L; Hagström, A

    1999-06-30

    In this paper we describe the development of a nested RT-PCR assay for the rapid diagnosis and characterisation of influenza virus directly from clinical specimens. Viral RNA is extracted from nasal swabs by the guanidine thiocyanate extraction method, and subsequently reverse transcribed. The complementary DNA is then used as template in a nested PCR reaction. Primers designed for use in this assay are specific for three templates; (1) the nucleoprotein (NP) gene, (2) the haemagglutinin gene of the H7N7 equine influenza virus (A1), and (3) the haemagglutinin gene of the H3N8 equine influenza virus (A2). We show that the assays are specific for the target genes chosen, and display sensitivity similar to virus isolation. The NP assay detects a variety of different influenza subtypes, whereas A1 and A2 assays are specific for influenza subtypes H7N7 and H3N8, respectively. Sequencing of amplicons obtained in the A2 assay yields information on antigenic regions of the haemagglutinin molecule, and use of this procedure in the routine surveillance of equine influenza will enable tentative characterisation of circulating viruses despite difficulties in isolating field strains of the H3N8 subtype. The A1 assay will be useful in ascertaining whether viruses of the H7N7 subtype still circulate amongst horses, or whether these are extinct. PMID:10418871

  6. Influenza A Viruses of Human Origin in Swine, Brazil.

    PubMed

    Nelson, Martha I; Schaefer, Rejane; Gava, Danielle; Cantão, Maurício Egídio; Ciacci-Zanella, Janice Reis

    2015-08-01

    The evolutionary origins of the influenza A(H1N1)pdm09 virus that caused the first outbreak of the 2009 pandemic in Mexico remain unclear, highlighting the lack of swine surveillance in Latin American countries. Although Brazil has one of the largest swine populations in the world, influenza was not thought to be endemic in Brazil's swine until the major outbreaks of influenza A(H1N1)pdm09 in 2009. Through phylogenetic analysis of whole-genome sequences of influenza viruses of the H1N1, H1N2, and H3N2 subtypes collected in swine in Brazil during 2009-2012, we identified multiple previously uncharacterized influenza viruses of human seasonal H1N2 and H3N2 virus origin that have circulated undetected in swine for more than a decade. Viral diversity has further increased in Brazil through reassortment between co-circulating viruses, including A(H1N1)pdm09. The circulation of multiple divergent hemagglutinin lineages challenges the design of effective cross-protective vaccines and highlights the need for additional surveillance. PMID:26196759

  7. Influenza A Viruses of Human Origin in Swine, Brazil

    PubMed Central

    Schaefer, Rejane; Gava, Danielle; Cantão, Maurício Egídio; Ciacci-Zanella, Janice Reis

    2015-01-01

    The evolutionary origins of the influenza A(H1N1)pdm09 virus that caused the first outbreak of the 2009 pandemic in Mexico remain unclear, highlighting the lack of swine surveillance in Latin American countries. Although Brazil has one of the largest swine populations in the world, influenza was not thought to be endemic in Brazil’s swine until the major outbreaks of influenza A(H1N1)pdm09 in 2009. Through phylogenetic analysis of whole-genome sequences of influenza viruses of the H1N1, H1N2, and H3N2 subtypes collected in swine in Brazil during 2009–2012, we identified multiple previously uncharacterized influenza viruses of human seasonal H1N2 and H3N2 virus origin that have circulated undetected in swine for more than a decade. Viral diversity has further increased in Brazil through reassortment between co-circulating viruses, including A(H1N1)pdm09. The circulation of multiple divergent hemagglutinin lineages challenges the design of effective cross-protective vaccines and highlights the need for additional surveillance. PMID:26196759

  8. Influenza virus neuraminidase: structure, antibodies, and inhibitors.

    PubMed Central

    Colman, P. M.

    1994-01-01

    The determination of the 3-dimensional structure of the influenza virus neuraminidase in 1983 has served as a platform for understanding interactions between antibodies and protein antigens, for investigating antigenic variation in influenza viruses, and for devising new inhibitors of the enzyme. That work is reviewed here, together with more recent developments that have resulted in one of the inhibitors entering clinical trials as an anti-influenza virus drug. PMID:7849585

  9. Highly Pathogenic Avian Influenza Virus (H5N1) Outbreak in Captive Wild Birds and Cats, Cambodia

    PubMed Central

    Marx, Nick; Ong, Sivuth; Gaidet, Nicolas; Hunt, Matt; Manuguerra, Jean-Claude; Sorn, San; Peiris, Malik; Van der Werf, Sylvie; Reynes, Jean-Marc

    2009-01-01

    From December 2003 through January 2004, the Phnom Tamao Wildlife Rescue Centre, Cambodia, was affected by the highly pathogenic influenza virus (H5N1). Birds from 26 species died. Influenza virus subtype H5N1 was detected in 6 of 7 species tested. Cats from 5 of 7 species were probably infected; none died. PMID:19239769

  10. Pathogenicity of recombinant H5N1 avian influenza viruses with truncated NS1 gene in chickens

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The NS1 protein of influenza A virus plays an important role in blocking the induction of type I interferon and other regulatory functions in infected cells. However, differences in length of the NS1 protein has been observed in highly pathogenic H5N1, H5N2, and H7N1 subtype avian influenza viruses...

  11. VIRUS VACCINE RESEARCH AT THE NATIONAL ANIMAL DISEASE CENTER: LESSONS FROM SWINE INFLUENZA VIRUS AND BOVINE VIRAL DIARRHEA VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The continuing emergence of novel subtypes and genetic variants of swine influenza viruses (SIV) causing swine flu challenges our ability to effectively manage this high morbidity disease among swine. New strategic approaches for vaccine development must be considered to keep up with the ever-evolv...

  12. Heterogeneous and Dynamic Prevalence of Asymptomatic Influenza Virus Infections.

    PubMed

    Furuya-Kanamori, Luis; Cox, Mitchell; Milinovich, Gabriel J; Magalhaes, Ricardo J Soares; Mackay, Ian M; Yakob, Laith

    2016-06-01

    Influenza infection manifests in a wide spectrum of severity, including symptomless pathogen carriers. We conducted a systematic review and meta-analysis of 55 studies to elucidate the proportional representation of these asymptomatic infected persons. We observed extensive heterogeneity among these studies. The prevalence of asymptomatic carriage (total absence of symptoms) ranged from 5.2% to 35.5% and subclinical cases (illness that did not meet the criteria for acute respiratory or influenza-like illness) from 25.4% to 61.8%. Statistical analysis showed that the heterogeneity could not be explained by the type of influenza, the laboratory tests used to detect the virus, the year of the study, or the location of the study. Projections of infection spread and strategies for disease control require that we identify the proportional representation of these insidious spreaders early on in the emergence of new influenza subtypes or strains and track how this rate evolves over time and space. PMID:27191967

  13. Heterogeneous and Dynamic Prevalence of Asymptomatic Influenza Virus Infections

    PubMed Central

    Furuya-Kanamori, Luis; Cox, Mitchell; Milinovich, Gabriel J.; Magalhaes, Ricardo J. Soares; Mackay, Ian M.

    2016-01-01

    Influenza infection manifests in a wide spectrum of severity, including symptomless pathogen carriers. We conducted a systematic review and meta-analysis of 55 studies to elucidate the proportional representation of these asymptomatic infected persons. We observed extensive heterogeneity among these studies. The prevalence of asymptomatic carriage (total absence of symptoms) ranged from 5.2% to 35.5% and subclinical cases (illness that did not meet the criteria for acute respiratory or influenza-like illness) from 25.4% to 61.8%. Statistical analysis showed that the heterogeneity could not be explained by the type of influenza, the laboratory tests used to detect the virus, the year of the study, or the location of the study. Projections of infection spread and strategies for disease control require that we identify the proportional representation of these insidious spreaders early on in the emergence of new influenza subtypes or strains and track how this rate evolves over time and space. PMID:27191967

  14. Virological Surveillance of Influenza Viruses during the 2008–09, 2009–10 and 2010–11 Seasons in Tunisia

    PubMed Central

    El Moussi, Awatef; Pozo, Francisco; Ben Hadj Kacem, Mohamed Ali; Ledesma, Juan; Cuevas, Maria Teresa; Casas, Inmaculada; Slim, Amine

    2013-01-01

    Background The data contribute to a better understanding of the circulation of influenza viruses especially in North-Africa. Objective The objective of this surveillance was to detect severe influenza cases, identify their epidemiological and virological characteristics and assess their impact on the healthcare system. Method We describe in this report the findings of laboratory-based surveillance of human cases of influenza virus and other respiratory viruses' infection during three seasons in Tunisia. Results The 2008–09 winter influenza season is underway in Tunisia, with co-circulation of influenza A/H3N2 (56.25%), influenza A(H1N1) (32.5%), and a few sporadic influenza B viruses (11.25%). In 2010–11 season the circulating strains are predominantly the 2009 pandemic influenza A(H1N1)pdm09 (70%) and influenza B viruses (22%). And sporadic viruses were sub-typed as A/H3N2 and unsubtyped influenza A, 5% and 3%, respectively. Unlike other countries, highest prevalence of influenza B virus Yamagata-like lineage has been reported in Tunisia (76%) localised into the clade B/Bangladesh/3333/2007. In the pandemic year, influenza A(H1N1)pdm09 predominated over other influenza viruses (95%). Amino acid changes D222G and D222E were detected in the HA gene of A(H1N1)pdm09 virus in two severe cases, one fatal case and one mild case out of 50 influenza A(H1N1)pdm09 viruses studied. The most frequently reported respiratory virus other than influenza in three seasons was RSV (45.29%). Conclusion This article summarises the surveillance and epidemiology of influenza viruses and other respiratory viruses, showing how rapid improvements in influenza surveillance were feasible by connecting the existing structure in the health care system for patient records to electronic surveillance system for reporting ILI cases. PMID:24069267

  15. DIVA vaccination strategies for avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vaccination for both low pathogenic and highly pathogenic avian influenza is commonly used for countries that have been endemic for avian influenza influenza virus, but stamping out policies are common for countries that are normally free of the disease. Stamping out policies of euthanizing infecte...

  16. Rapid Detection of Subtype H10N8 Influenza Virus by One-Step Reverse Transcription–Loop-Mediated Isothermal Amplification Methods

    PubMed Central

    Bao, Hongmei; Feng, Xiaoxiao; Ma, Yong; Shi, Jianzhong; Zhao, Yuhui; Gu, Linlin

    2015-01-01

    We developed hemagglutinin- and neuraminidase-specific one-step reverse transcription–loop-mediated isothermal amplification assays for detecting the H10N8 virus. The detection limit of the assays was 10 copies of H10N8 virus, and the assays did not amplify nonspecific RNA. The assays can detect H10N8 virus from chicken samples with high sensitivity and specificity, and they can serve as an effective tool for detecting and monitoring H10N8 virus in live poultry markets. PMID:26378283

  17. An Anti-Influenza Virus Antibody Inhibits Viral Infection by Reducing Nucleus Entry of Influenza Nucleoprotein

    PubMed Central

    Yoon, Aerin; Yi, Kye Sook; Chang, So Young; Kim, Sung Hwan; Song, Manki; Choi, Jung Ah; Bourgeois, Melissa; Hossain, M. Jaber; Chen, Li-Mei; Donis, Ruben O.; Kim, Hyori; Lee, Yujean; Hwang, Do Been; Min, Ji-Young; Chang, Shin Jae; Chung, Junho

    2015-01-01

    To date, four main mechanisms mediating inhibition of influenza infection by anti-hemagglutinin antibodies have been reported. Anti-globular-head-domain antibodies block either influenza virus receptor binding to the host cell or progeny virion release from the host cell. Anti-stem region antibodies hinder the membrane fusion process or induce antibody-dependent cytotoxicity to infected cells. In this study we identified a human monoclonal IgG1 antibody (CT302), which does not inhibit both the receptor binding and the membrane fusion process but efficiently reduced the nucleus entry of viral nucleoprotein suggesting a novel inhibition mechanism of viral infection by antibody. This antibody binds to the subtype-H3 hemagglutinin globular head domain of group-2 influenza viruses circulating throughout the population between 1997 and 2007. PMID:26512723

  18. An Anti-Influenza Virus Antibody Inhibits Viral Infection by Reducing Nucleus Entry of Influenza Nucleoprotein.

    PubMed

    Yoon, Aerin; Yi, Kye Sook; Chang, So Young; Kim, Sung Hwan; Song, Manki; Choi, Jung Ah; Bourgeois, Melissa; Hossain, M Jaber; Chen, Li-Mei; Donis, Ruben O; Kim, Hyori; Lee, Yujean; Hwang, Do Been; Min, Ji-Young; Chang, Shin Jae; Chung, Junho

    2015-01-01

    To date, four main mechanisms mediating inhibition of influenza infection by anti-hemagglutinin antibodies have been reported. Anti-globular-head-domain antibodies block either influenza virus receptor binding to the host cell or progeny virion release from the host cell. Anti-stem region antibodies hinder the membrane fusion process or induce antibody-dependent cytotoxicity to infected cells. In this study we identified a human monoclonal IgG1 antibody (CT302), which does not inhibit both the receptor binding and the membrane fusion process but efficiently reduced the nucleus entry of viral nucleoprotein suggesting a novel inhibition mechanism of viral infection by antibody. This antibody binds to the subtype-H3 hemagglutinin globular head domain of group-2 influenza viruses circulating throughout the population between 1997 and 2007. PMID:26512723

  19. Hemagglutinin Sequence Conservation Guided Stem Immunogen Design from Influenza A H3 Subtype

    PubMed Central

    Mallajosyula, V. Vamsee Aditya; Citron, Michael; Ferrara, Francesca; Temperton, Nigel J.; Liang, Xiaoping; Flynn, Jessica A.; Varadarajan, Raghavan

    2015-01-01

    Seasonal epidemics caused by influenza A (H1 and H3 subtypes) and B viruses are a major global health threat. The traditional, trivalent influenza vaccines have limited efficacy because of rapid antigenic evolution of the circulating viruses. This antigenic variability mediates viral escape from the host immune responses, necessitating annual vaccine updates. Influenza vaccines elicit a protective antibody response, primarily targeting the viral surface glycoprotein hemagglutinin (HA). However, the predominant humoral response is against the hypervariable head domain of HA, thereby restricting the breadth of protection. In contrast, the conserved, subdominant stem domain of HA is a potential “universal” vaccine candidate. We designed an HA stem-fragment immunogen from the 1968 pandemic H3N2 strain (A/Hong Kong/1/68) guided by a comprehensive H3 HA sequence conservation analysis. The biophysical properties of the designed immunogen were further improved by C-terminal fusion of a trimerization motif, “isoleucine-zipper”, or “foldon”. These immunogens elicited cross-reactive, antiviral antibodies and conferred partial protection against a lethal, homologous HK68 virus challenge in vivo. Furthermore, bacterial expression of these immunogens is economical and facilitates rapid scale-up. PMID:26167164

  20. Analysis of antigenic variation in equine 2 influenza A viruses.

    PubMed

    Hinshaw, V S; Naeve, C W; Webster, R G; Douglas, A; Skehel, J J; Bryans, J

    1983-01-01

    Influenza outbreaks involving viruses of the H3N8 subtype (equine 2) often occur in vaccinated horses. For this reason, a series of influenza viruses of the H3N8 subtype were examined to determine if antigenic variation could be detected in isolates during the period 1963-81. Antigenic analyses with post-infection ferret sera and monoclonal antibodies showed that the haemagglutinins of recent isolates were antigenically distinguishable from the prototype A/eq/Miami/1/63 and that antigenically distinguishable groups of equine 2 viruses co-circulate in the horse population. Based on these studies, it is recommended that a recent equine strain, A/equine/Fontainebleu/1/79 or A/equine/Kentucky/1/81, serve as an additional prototype strain for this subtype.Antigenic variation in equine 2 viruses may be of epidemiological significance, yet the overall conservation of these strains makes it unlikely that vaccine failures can be attributed solely to antigenic changes in these viruses. A sufficiently potent vaccine, containing a current representative of the most prevalent equine 2 strain, may improve the protection afforded by equine vaccines. PMID:6601538

  1. Influenza virus activation of the interferon system

    PubMed Central

    Killip, Marian J.; Fodor, Ervin; Randall, Richard E.

    2015-01-01

    The host interferon (IFN) response represents one of the first barriers that influenza viruses must surmount in order to establish an infection. Many advances have been made in recent years in understanding the interactions between influenza viruses and the interferon system. In this review, we summarise recent work regarding activation of the type I IFN response by influenza viruses, including attempts to identify the viral RNA responsible for IFN induction, the stage of the virus life cycle at which it is generated and the role of defective viruses in this process. PMID:25678267

  2. H9N2 avian influenza virus-derived natural reassortant H5N2 virus in swan containing the hemagglutinin segment from Eurasian H5 avian influenza virus with an in-frame deletion of four basic residues in the polybasic hemagglutinin cleavage site.

    PubMed

    Wang, Youling; Yuan, Xiaoyuan; Qi, Lihong; Zhang, Yuxia; Xu, Huaiying; Yang, Jinxing; Ai, Wu; Qi, Wenbao; Liao, Ming; Wang, Dan; Song, Minxun; Li, Feng

    2016-06-01

    We isolated a novel H5N2 avian influenza virus from swans in China. The virus was derived from a widespread H9N2 avian influenza virus but acquired the hemagglutinin gene from Eurasian H5 subtype with a naturally occurring in-frame deletion of four basic residues in the polybasic hemagglutinin cleavage site. PMID:26910357

  3. Biological and Protective Properties of Immune Sera Directed to the Influenza Virus Neuraminidase

    PubMed Central

    Halbherr, Stefan J.; Ludersdorfer, Thomas H.; Ricklin, Meret; Locher, Samira; Berger Rentsch, Marianne; Summerfield, Artur

    2014-01-01

    ABSTRACT The envelope of influenza A viruses contains two large antigens, hemagglutinin (HA) and neuraminidase (NA). Conventional influenza virus vaccines induce neutralizing antibodies that are predominantly directed to the HA globular head, a domain that is subject to extensive antigenic drift. Antibodies directed to NA are induced at much lower levels, probably as a consequence of the immunodominance of the HA antigen. Although antibodies to NA may affect virus release by inhibiting the sialidase function of the glycoprotein, the antigen has been largely neglected in past vaccine design. In this study, we characterized the protective properties of monospecific immune sera that were generated by vaccination with recombinant RNA replicon particles encoding NA. These immune sera inhibited hemagglutination in an NA subtype-specific and HA subtype-independent manner and interfered with infection of MDCK cells. In addition, they inhibited the sialidase activities of various influenza viruses of the same and even different NA subtypes. With this, the anti-NA immune sera inhibited the spread of H5N1 highly pathogenic avian influenza virus and HA/NA-pseudotyped viruses in MDCK cells in a concentration-dependent manner. When chickens were immunized with NA recombinant replicon particles and subsequently infected with low-pathogenic avian influenza virus, inflammatory serum markers were significantly reduced and virus shedding was limited or eliminated. These findings suggest that NA antibodies can inhibit virus dissemination by interfering with both virus attachment and egress. Our results underline the potential of high-quality NA antibodies for controlling influenza virus replication and place emphasis on NA as a vaccine antigen. IMPORTANCE The neuraminidase of influenza A viruses is a sialidase that acts as a receptor-destroying enzyme facilitating the release of progeny virus from infected cells. Here, we demonstrate that monospecific anti-NA immune sera inhibited not

  4. Virulence determinants of pandemic influenza viruses

    PubMed Central

    Tscherne, Donna M.; García-Sastre, Adolfo

    2011-01-01

    Influenza A viruses cause recurrent, seasonal epidemics and occasional global pandemics with devastating levels of morbidity and mortality. The ability of influenza A viruses to adapt to various hosts and undergo reassortment events ensures constant generation of new strains with unpredictable degrees of pathogenicity, transmissibility, and pandemic potential. Currently, the combination of factors that drives the emergence of pandemic influenza is unclear, making it impossible to foresee the details of a future outbreak. Identification and characterization of influenza A virus virulence determinants may provide insight into genotypic signatures of pathogenicity as well as a more thorough understanding of the factors that give rise to pandemics. PMID:21206092

  5. Swine influenza virus: epidemiology and vaccine concerns

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Introduction. Swine influenza virus (SIV) is a primary cause of respiratory disease in swine and a component of the porcine respiratory disease complex (PRDC). Influenza viruses are an important health and economic concern for swine producers throughout the world. Swine operations may be affected by...

  6. The receptor preference of influenza viruses

    PubMed Central

    Meng, Bo; Marriott, Anthony C.; Dimmock, Nigel J.

    2010-01-01

    Please cite this paper as: Meng et al. (2010) The receptor preference of influenza viruses. Influenza and Other Respiratory Viruses 4(3), 147–153. Objectives  The cell surface receptor used by an influenza virus to infect that cell is an N‐acetyl neuraminic acid (NANA) residue terminally linked by an alpha2,3 or alpha2,6 bond to a carbohydrate moiety of a glycoprotein or glycolipid. Our aim was to determine a quick and technically simple method to determine cell receptor usage by whole influenza A virus particles. Methods  We employed surface plasmon resonance to detect the binding of viruses to fetuin, a naturally occurring glycoprotein that has both alpha2,3‐ and alpha2,6‐linked NANA, and free 3′‐sialyllactose or 6′‐sialyllactose to compete virus binding. All virus stocks were produced in embryonated chicken’s eggs. Results  The influenza viruses tested bound preferentially to NANAalpha2,3Gal or to NANAalpha2,6Gal, or showed no preference. Two PR8 viruses had different binding preferences. Binding preferences of viruses correlated well with their known biological properties. Conclusions  Our data suggest that it is not easy to predict receptor usage by influenza viruses. However, direct experimental determination as described here can inform experiments concerned with viral pathogenesis, biology and structure. In principle, the methodology can be used for any virus that binds to a terminal NANA residue. PMID:20409211

  7. The pathogenesis of H3N8 canine influenza virus in chickens, turkeys and ducks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canine influenza virus (CIV) of the H3N8 subtype has emerged in dog populations throughout the U.S. where is has become endemic in kennels and animal shelters in some regions. It has not previously been determined whether the canine adapted virus can be transmitted to domestic poultry, which are su...

  8. High doses of highly pathogenic avian influenza virus in chicken meat are required to infect ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    H5N1 high pathogenicity avian influenza viruses (HPAIV) have caused natural and experimental infections in various animals through consumption of infected bird carcasses and meat. However, little is known about the quantity of virus required and if all HPAIV subtypes can cause infections following c...

  9. Rapid preparation of mutated influenza hemagglutinins for influenza virus pandemic prevention.

    PubMed

    Nishioka, Ryosuke; Satomura, Atsushi; Yamada, Junki; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2016-03-01

    Influenza viruses have periodically caused pandemic due to frequent mutation of viral proteins. Influenza viruses have two major membrane glycoproteins: hemagglutinin (HA) and neuraminidase (NA). Hemagglutinin plays a crucial role in viral entry, while NA is involved in the process of a viral escape. In terms of developing antiviral drugs, HA is a more important target than NA in the prevention of pandemic, since HA is likely to change the host specificity of a virus by acquiring mutations, thereby to increase the risk of pandemic. To characterize mutated HA functions, current approaches require immobilization of purified HA on plastic wells and carriers. These troublesome methods make it difficult to respond to emerging mutations. In order to address this problem, a yeast cell surface engineering approach was investigated. Using this technology, human HAs derived from various H1N1 subtypes were successfully and rapidly displayed on the yeast cell surface. The yeast-displayed HAs exhibited similar abilities to native influenza virus HAs. Using this system, human HAs with 190E and 225G mutations were shown to exhibit altered recognition specificities from human to avian erythrocytes. This system furthermore allowed direct measurement of HA binding abilities without protein purification and immobilization. Coupled with the ease of genetic manipulation, this system allows the simple and comprehensive construction of mutant protein libraries on yeast cell surface, thereby contributing to influenza virus pandemic prevention. PMID:26797882

  10. Live, attenuated influenza virus (LAIV) vehicles are strong inducers of immunity toward influenza B virus

    PubMed Central

    Huber, Victor C.; Kleimeyer, Loren H.; McCullers, Jonathan A.

    2008-01-01

    Historically, vaccines developed toward influenza viruses of the B type using methodologies developed for influenza A viruses as a blueprint have not been equally efficacious or effective. Because most influenza research and public attention concerns influenza A viruses, these shortcomings have not been adequately addressed. In this manuscript, we utilized different influenza vaccine vehicles to compare immunogenicity and protection in mice and ferrets after vaccination against an influenza B virus. We report that plasmid DNA vaccines demonstrate low immunogenicity profiles and poor protection compared to either whole, inactivated influenza virus (IIV) or, live, attenuated influenza virus (LAIV) vaccines. When mixed prime:boost regimens using LAIV and IIV were studied, we observed a boosting effect in mice after priming with LAIV that was not seen when IIV was used as the prime. In ferrets LAIV induced high antibody titers after a single dose and provided a boost in IIV-primed animals. Regimens including LAIV as a prime demonstrated enhanced protection, and adjuvantation was required for efficacy using the IIV preparation. Our results differ from generally accepted influenza A virus vaccine models, and argue that strategies for control of influenza B virus should be considered separately from those for influenza A virus. PMID:18708106

  11. Media Use and Communication Inequalities in a Public Health Emergency: A Case Study of 2009–2010 Pandemic Influenza A Virus Subtype H1N1

    PubMed Central

    Jung, Minsoo; McCloud, Rachel F.; Viswanath, Kasisomayajula

    2014-01-01

    Objectives Studies have shown that differences among individuals and social groups in accessing and using information on health and specific threats have an impact on their knowledge and behaviors. These differences, characterized as communication inequalities, may hamper the strength of a society's response to a public health emergency. Such inequalities not only make vulnerable populations subject to a disproportionate burden of adversity, but also compromise the public health system's efforts to prevent and respond to pandemic influenza outbreaks. We investigated the effect of socioeconomic status (SES) and health communication behaviors (including barriers) on people's knowledge and misconceptions about pandemic influenza A(H1N1) (pH1N1) and adoption of prevention behaviors. Methods The data for this study came from a survey of 1,569 respondents drawn from a nationally representative sample of American adults during pH1N1. We conducted logistic regression analyses when appropriate. Results We found that (1) SES has a significant association with barriers to information access and processing, levels of pH1N1-related knowledge, and misconceptions; (2) levels of pH1N1-related knowledge are associated positively with the adoption of recommended prevention measures and negatively with the adoption of incorrect protective behaviors; and (3) people with higher SES, higher news exposure, and higher levels of pH1N1-related knowledge, as well as those who actively seek information, are less likely than their counterparts to adopt incorrect prevention behaviors. Conclusion Strategic public health communication efforts in public health preparedness and during emergencies should take into account potential communication inequalities and develop campaigns that reach across different social groups. PMID:25355975

  12. Cross-protective immunity to influenza A viruses.

    PubMed

    Epstein, Suzanne L; Price, Graeme E

    2010-11-01

    Antigenic changes in influenza virus occur gradually, owing to mutations (antigenic drift), and abruptly, owing to reassortment among subtypes (antigenic shift). Availability of strain-matched vaccines often lags behind these changes, resulting in a shortfall in public health. In animal models, cross-protection by vaccines based on conserved antigens does not completely prevent infection, but greatly reduces morbidity, mortality, virus replication and, thus, viral shedding and spread. Such immunity is especially effective and long-lasting with mucosal administration. Cross-protective immunity in humans is controversial, but is suggested by some epidemiological findings. 'Universal' vaccines protective against all influenza A viruses might substantially reduce severity of infection and limit spread of disease during outbreaks. These vaccines could be used 'off the shelf' early in an outbreak or pandemic, before strain-matched vaccines are available. PMID:21087110

  13. Respiratory tract versus cloacal sampling of migratory ducks for influenza A viruses: are both ends relevant?

    PubMed Central

    Krauss, Scott; Pryor, Sydney Paul; Raven, Garnet; Danner, Angela; Kayali, Ghazi; Webby, Richard J.; Webster, Robert G.

    2012-01-01

    Please cite this paper as: Krauss et al. (2012) Respiratory tract versus cloacal sampling of migratory ducks for influenza A viruses: are both ends relevant? Influenza and Other Respiratory Viruses DOI: . Background  Early studies in dabbling ducks showed that cloacal swabs yielded a larger number of avian influenza virus (AIV) isolates than did respiratory tract swabs. Historically, AIV surveillance has been performed by collecting cloacal or environmental fecal samples only. Highly pathogenic avian influenza H5N1 virus emerged in 1996 and replicated to higher titers in the respiratory rather than the gastrointestinal tract of ducks, prompting the collection of respiratory samples in addition to cloacal swabs from wild birds. Studies confirmed that some virus subtypes, especially H9 and highly pathogenic H5, are shed primarily through the respiratory tract and may not be detected in cloacal swabs. Objectives  To examine prevalence and subtype differences for AIV isolates from cloacal or respiratory swabs of wild ducks and to determine whether individual respiratory tract samples should be included in AIV surveillance studies in wild birds. Methods  Individual respiratory tract and cloacal swabs were collected from each of 1036 wild ducks in Alberta, Canada, during the month of August from 2007 to 2010 in an ongoing surveillance study. Virus isolation in eggs and subtype identification by antigenic and molecular methods were performed. Results and conclusions  Respiratory tract and cloacal swabs yielded ten influenza virus HA subtypes representing 28 HA–NA combinations. Three HA–NA subtype combinations were found exclusively in respiratory tract samples. Only four HA subtypes (H1, H3, H4, and H7) were recovered from respiratory samples, but respiratory shedding was associated with the dominance of 1 year’s subtype. Might respiratory shedding provide a risk assessment indicator? PMID:22458473

  14. Multiyear Surveillance for Avian Influenza Virus in Waterfowl from Wintering Grounds, Texas Coast, USA

    PubMed Central

    Ferro, Pamela J.; Budke, Christine M.; Peterson, Markus J.; Cox, Dayna; Roltsch, Emily; Merendino, Todd; Nelson, Matt

    2010-01-01

    We studied the prevalence of influenza A virus in wintering waterfowl from the Central Flyway on the Gulf Coast of Texas. Of 5,363 hunter-harvested migratory and resident waterfowl and wetland-associated game birds sampled during 3 consecutive hunting seasons (September–January 2006–07, 2007–08, and 2008–09), real-time reverse transcription–PCR detected influenza A matrix sequences in 8.5% of samples, H5 in 0.7%, and H7 in 0.6%. Virus isolation yielded 134 influenza A viruses, including N1–N9, H1–H7, H10, and H11 subtypes. Low-pathogenicity H7 subtype was isolated during January, September, and November 2007 and January 2008; low-pathogenicity H5 subtype was isolated during November and December 2007. PMID:20678315

  15. An MDCK Cell Culture-Derived Formalin-Inactivated Influenza Virus Whole-Virion Vaccine from an Influenza Virus Library Confers Cross-Protective Immunity by Intranasal Administration in Mice

    PubMed Central

    Haredy, Ahmad M.; Takenaka, Nobuyuki; Yamada, Hiroshi; Sakoda, Yoshihiro; Okamatsu, Masatoshi; Yamamoto, Naoki; Omasa, Takeshi; Ohtake, Hisao; Mori, Yasuko; Kida, Hiroshi; Yamanishi, Koichi

    2013-01-01

    It is currently impossible to predict the next pandemic influenza virus strain. We have thus established a library of influenza viruses of all hemagglutinin and neuraminidase subtypes and their genes. In this article, we examine the applicability of a rapid production model for the preparation of vaccines against emerging pandemic influenza viruses. This procedure utilizes the influenza virus library, cell culture-based vaccine production, and intranasal administration to induce a cross-protective immune response. First, an influenza virus reassortant from the library, A/duck/Hokkaido/Vac-3/2007 (H5N1), was passaged 22 times (P22) in Madin-Darby canine kidney (MDCK) cells. The P22 virus had a titer of >2 ×108 PFU/ml, which was 40 times that of the original strain, with 4 point mutations, which altered amino acids in the deduced protein sequences encoded by the PB2 and PA genes. We then produced a formalin-inactivated whole-virion vaccine from the MDCK cell-cultured A/duck/Hokkaido/Vac-3/2007 (H5N1) P22 virus. Intranasal immunization of mice with this vaccine protected them against challenges with lethal influenza viruses of homologous and heterologous subtypes. We further demonstrated that intranasal immunization with the vaccine induced cross-reactive neutralizing antibody responses against the homotypic H5N1 influenza virus and its antigenic variants and cross-reactive cell-mediated immune responses to the homologous virus, its variants within a subtype, and even an influenza virus of a different subtype. These results indicate that a rapid model for emergency vaccine production may be effective for producing the next generation of pandemic influenza virus vaccines. PMID:23637045

  16. Structure and Function Analysis of an Antibody Recognizing All Influenza A Subtypes.

    PubMed

    Kallewaard, Nicole L; Corti, Davide; Collins, Patrick J; Neu, Ursula; McAuliffe, Josephine M; Benjamin, Ebony; Wachter-Rosati, Leslie; Palmer-Hill, Frances J; Yuan, Andy Q; Walker, Philip A; Vorlaender, Matthias K; Bianchi, Siro; Guarino, Barbara; De Marco, Anna; Vanzetta, Fabrizia; Agatic, Gloria; Foglierini, Mathilde; Pinna, Debora; Fernandez-Rodriguez, Blanca; Fruehwirth, Alexander; Silacci, Chiara; Ogrodowicz, Roksana W; Martin, Stephen R; Sallusto, Federica; Suzich, JoAnn A; Lanzavecchia, Antonio; Zhu, Qing; Gamblin, Steven J; Skehel, John J

    2016-07-28

    Influenza virus remains a threat because of its ability to evade vaccine-induced immune responses due to antigenic drift. Here, we describe the isolation, evolution, and structure of a broad-spectrum human monoclonal antibody (mAb), MEDI8852, effectively reacting with all influenza A hemagglutinin (HA) subtypes. MEDI8852 uses the heavy-chain VH6-1 gene and has higher potency and breadth when compared to other anti-stem antibodies. MEDI8852 is effective in mice and ferrets with a therapeutic window superior to that of oseltamivir. Crystallographic analysis of Fab alone or in complex with H5 or H7 HA proteins reveals that MEDI8852 binds through a coordinated movement of CDRs to a highly conserved epitope encompassing a hydrophobic groove in the fusion domain and a large portion of the fusion peptide, distinguishing it from other structurally characterized cross-reactive antibodies. The unprecedented breadth and potency of neutralization by MEDI8852 support its development as immunotherapy for influenza virus-infected humans. PMID:27453466

  17. Influenza virus surveillance in Argentina during the 2012 season: antigenic characterization, genetic analysis and antiviral susceptibility.

    PubMed

    Benedetti, E; Daniels, R S; Pontoriero, A; Russo, M; Avaro, M; Czech, A; Campos, A; Periolo, N; Gregory, V; McCauley, J W; Baumeister, E G

    2016-03-01

    The activity and circulation of influenza viruses in Argentina was studied during 2012 as part of the Argentinean Surveillance for Influenza and other Respiratory Viruses, in the context of Global Influenza Surveillance. The antigenicity and molecular characteristics of haemagglutinins (HA) of circulating influenza A and B viruses were analysed to assess the emergence of virus variants. Susceptibility to oseltamivir and zanamivir was evaluated by enzymatic assay and results were backed-up by sequencing of the neuraminidase (NA) genes. During the 2012 season, influenza virus circulation in Argentina was detected from weeks 24 to 51. The HA sequences of the studied A(H1N1)pdm09 subtype viruses segregated in a different genetic group compared to those identified during the 2009 pandemic, although they were still closely related antigenically to the vaccine virus A/California/07/2009. The HA sequences of the A(H3N2) viruses analysed fell into the A/Victoria/208/2009 clade, genetic group 3C. A mixed circulation of virus variants belonging to B/Victoria and B/Yamagata lineages was detected, with B/Victoria being dominant. All viruses tested were sensitive to oseltamivir and zanamivir except one. This isolate, an A(H1N1)pdm09 virus possessing the substitution NA-N295S, showed highly reduced inhibition by oseltamivir and reduced inhibition by zanamivir. Virological and epidemiological surveillance remains critical for detection of evolving influenza viruses. PMID:26345289

  18. Neutralization enzyme immunoassay for influenza virus.

    PubMed Central

    Benne, C A; Harmsen, M; De Jong, J C; Kraaijeveld, C A

    1994-01-01

    A neutralization enzyme immunoassay (N-EIA) was developed for the detection of antibody titer rises in sera of patients infected with influenza A (H3N2) virus. In this N-EIA, a selected strain of influenza A (H3N2) virus was added to monolayers of LLC-MK2 cells in microtiter plates. After 24 h, the replicated virus could be demonstrated with a virus-specific enzyme-labeled monoclonal antibody. Preincubation of the influenza virus with convalescent-phase sera of patients infected with influenza A (H3N2) virus resulted 1 day later in decreased absorbance values that could be used for calculation of neutralization titers. From use of paired serum samples from 10 patients with a history of flu-like symptoms, the results obtained with N-EIA correlated well (r = 0.83) with those of the standard hemagglutination inhibition test. PMID:8027355

  19. Serological evidence of influenza A viruses in frugivorous bats from Africa.

    PubMed

    Freidl, Gudrun Stephanie; Binger, Tabea; Müller, Marcel Alexander; de Bruin, Erwin; van Beek, Janko; Corman, Victor Max; Rasche, Andrea; Drexler, Jan Felix; Sylverken, Augustina; Oppong, Samuel K; Adu-Sarkodie, Yaw; Tschapka, Marco; Cottontail, Veronika M; Drosten, Christian; Koopmans, Marion

    2015-01-01

    Bats are likely natural hosts for a range of zoonotic viruses such as Marburg, Ebola, Rabies, as well as for various Corona- and Paramyxoviruses. In 2009/10, researchers discovered RNA of two novel influenza virus subtypes--H17N10 and H18N11--in Central and South American fruit bats. The identification of bats as possible additional reservoir for influenza A viruses raises questions about the role of this mammalian taxon in influenza A virus ecology and possible public health relevance. As molecular testing can be limited by a short time window in which the virus is present, serological testing provides information about past infections and virus spread in populations after the virus has been cleared. This study aimed at screening available sera from 100 free-ranging, frugivorous bats (Eidolon helvum) sampled in 2009/10 in Ghana, for the presence of antibodies against the complete panel of influenza A haemagglutinin (HA) types ranging from H1 to H18 by means of a protein microarray platform. This technique enables simultaneous serological testing against multiple recombinant HA-types in 5 μl of serum. Preliminary results indicate serological evidence against avian influenza subtype H9 in about 30% of the animals screened, with low-level cross-reactivity to phylogenetically closely related subtypes H8 and H12. To our knowledge, this is the first report of serological evidence of influenza A viruses other than H17 and H18 in bats. As avian influenza subtype H9 is associated with human infections, the implications of our findings from a public health context remain to be investigated. PMID:25965069

  20. Serological Evidence of Influenza A Viruses in Frugivorous Bats from Africa

    PubMed Central

    Müller, Marcel Alexander; de Bruin, Erwin; van Beek, Janko; Corman, Victor Max; Rasche, Andrea; Drexler, Jan Felix; Sylverken, Augustina; Oppong, Samuel K.; Adu-Sarkodie, Yaw; Tschapka, Marco; Cottontail, Veronika M.; Drosten, Christian; Koopmans, Marion

    2015-01-01

    Bats are likely natural hosts for a range of zoonotic viruses such as Marburg, Ebola, Rabies, as well as for various Corona- and Paramyxoviruses. In 2009/10, researchers discovered RNA of two novel influenza virus subtypes – H17N10 and H18N11 – in Central and South American fruit bats. The identification of bats as possible additional reservoir for influenza A viruses raises questions about the role of this mammalian taxon in influenza A virus ecology and possible public health relevance. As molecular testing can be limited by a short time window in which the virus is present, serological testing provides information about past infections and virus spread in populations after the virus has been cleared. This study aimed at screening available sera from 100 free-ranging, frugivorous bats (Eidolon helvum) sampled in 2009/10 in Ghana, for the presence of antibodies against the complete panel of influenza A haemagglutinin (HA) types ranging from H1 to H18 by means of a protein microarray platform. This technique enables simultaneous serological testing against multiple recombinant HA-types in 5μl of serum. Preliminary results indicate serological evidence against avian influenza subtype H9 in about 30% of the animals screened, with low-level cross-reactivity to phylogenetically closely related subtypes H8 and H12. To our knowledge, this is the first report of serological evidence of influenza A viruses other than H17 and H18 in bats. As avian influenza subtype H9 is associated with human infections, the implications of our findings from a public health context remain to be investigated. PMID:25965069

  1. Study of Oseltamivir and Zanamivir Resistance-Related Mutations in Influenza Viruses Isolated from Wild Mallards in Sweden

    PubMed Central

    Orozovic, Goran; Orozovic, Kanita; Järhult, Josef D.; Olsen, Björn

    2014-01-01

    Resistance to neuraminidase inhibitors (NAIs) is a growing problem in battle against influenza A virus. However, little is known about the resistance of viruses isolated from dabbling ducks, the natural reservoir of the influenza virus. To our knowledge, no low-pathogenic avian influenza (LPAI) virus resistant to NAIs has been detected. The aim of this study was to investigate mallard isolates of influenza A virus previously identified to carry oseltamivir carboxylate (OC) or zanamivir (ZA) resistance-related mutations. In this work, 21 viruses belonging to the N1, N3, N6 and N9 subtypes were analyzed using a colorimetric NA inhibition assay. The results of assay showed no NAIs-resistant phenotype for any of the viruses. The R118K mutation was the most recurrent, as it was observed in all subtypes except for N6. IC50 values confirmed the differences in sensitivity to OC or ZA observed in the N1 and N2 groups of NAs. Furthermore, both wild types (WTs) in the N6 and one WT in the N9 subtype were less sensitive to ZA than were genotypically related mutants with R152K and R118K change in the respective subtypes. This may indicate that these and probably even other NAIs resistance-related mutations found in our virus collection were not induced by NAIs residuals in the environment and that the impact of such mutations in an avian influenza could be dependent on subtype, strain and host species. PMID:24558492

  2. Fluorescent Immunochromatography for Rapid and Sensitive Typing of Seasonal Influenza Viruses

    PubMed Central

    Sakurai, Akira; Takayama, Katsuyoshi; Nomura, Namiko; Kajiwara, Naoki; Okamatsu, Masatoshi; Yamamoto, Naoki; Tamura, Tsuruki; Yamada, Jitsuho; Hashimoto, Masako; Sakoda, Yoshihiro; Suda, Yoshihiko; Kobayashi, Yukuharu; Kida, Hiroshi; Shibasaki, Futoshi

    2015-01-01

    Lateral flow tests also known as Immunochromatography (IC) is an antigen-detection method conducted on a nitrocellulose membrane that can be completed in less than 20 min. IC has been used as an important rapid test for clinical diagnosis and surveillance of influenza viruses, but the IC sensitivity is relatively low (approximately 60%) and the limit of detection (LOD) is as low as 10³ pfu per reaction. Recently, we reported an improved IC assay using antibodies conjugated with fluorescent beads (fluorescent immunochromatography; FLIC) for subtyping H5 influenza viruses (FLIC-H5). Although the FLIC strip must be scanned using a fluorescent reader, the sensitivity (LOD) is significantly improved over that of conventional IC methods. In addition, the antibodies which are specific against the subtypes of influenza viruses cannot be available for the detection of other subtypes when the major antigenicity will be changed. In this study, we established the use of FLIC to type seasonal influenza A and B viruses (FLIC-AB). This method has improved sensitivity to 100-fold higher than that of conventional IC methods when we used several strains of influenza viruses. In addition, FLIC-AB demonstrated the ability to detect influenza type A and influenza type B viruses from clinical samples with high sensitivity and specificity (Type A: sensitivity 98.7% (74/75), specificity 100% (54/54), Type B: sensitivity 100% (90/90), specificity 98.2% (54/55) in nasal swab samples) in comparison to the results of qRT-PCR. And furthermore, FLIC-AB performs better in the detection of early stage infection (under 13h) than other conventional IC methods. Our results provide new strategies to prevent the early-stage transmission of influenza viruses in humans during both seasonal outbreaks and pandemics. PMID:25650570

  3. Potent Neutralization of Influenza A Virus by a Single-Domain Antibody Blocking M2 Ion Channel Protein

    PubMed Central

    Wei, Guowei; Meng, Weixu; Guo, Haijiang; Pan, Weiqi; Liu, Jinsong; Peng, Tao; Chen, Ling; Chen, Chang-You

    2011-01-01

    Influenza A virus poses serious health threat to humans. Neutralizing antibodies against the highly conserved M2 ion channel is thought to offer broad protection against influenza A viruses. Here, we screened synthetic Camel single-domain antibody (VHH) libraries against native M2 ion channel protein. One of the isolated VHHs, M2-7A, specifically bound to M2-expressed cell membrane as well as influenza A virion, inhibited replication of both amantadine-sensitive and resistant influenza A viruses in vitro, and protected mice from a lethal influenza virus challenge. Moreover, M2-7A showed blocking activity for proton influx through M2 ion channel. These pieces of evidence collectively demonstrate for the first time that a neutralizing antibody against M2 with broad specificity is achievable, and M2-7A may have potential for cross protection against a number of variants and subtypes of influenza A viruses. PMID:22164266

  4. Transmission of Avian Influenza Virus (H3N2) to Dogs

    PubMed Central

    Song, Daesub; Kang, Bokyu; Lee, Chulseung; Jung, Kwonil; Ha, Gunwoo; Kang, Dongseok; Park, Seongjun; Park, Bongkyun

    2008-01-01

    In South Korea, where avian influenza virus subtypes H3N2, H5N1, H6N1, and H9N2 circulate or have been detected, 3 genetically similar canine influenza virus (H3N2) strains of avian origin (A/canine/Korea/01/2007, A/canine/Korea/02/2007, and A/canine/Korea/03/2007) were isolated from dogs exhibiting severe respiratory disease. To determine whether the novel canine influenza virus of avian origin was transmitted among dogs, we experimentally infected beagles with this influenza virus (H3N2) isolate. The beagles shed virus through nasal excretion, seroconverted, and became ill with severe necrotizing tracheobronchitis and bronchioalveolitis with accompanying clinical signs (e.g., high fever). Consistent with histologic observation of lung lesions, large amounts of avian influenza virus binding receptor (SAα 2,3-gal) were identified in canine tracheal, bronchial, and bronchiolar epithelial cells, which suggests potential for direct transmission of avian influenza virus (H3N2) from poultry to dogs. Our data provide evidence that dogs may play a role in interspecies transmission and spread of influenza virus. PMID:18439355

  5. Detailed Report on 2014/15 Influenza Virus Characteristics, and Estimates on Influenza Virus Vaccine Effectiveness from Austria’s Sentinel Physician Surveillance Network

    PubMed Central

    2016-01-01

    Background Influenza vaccine effectiveness (VE) is influenced by the antigenic similarity between vaccine- and circulating strains. Material and Methods This paper presents data obtained by the Austrian sentinel surveillance system on the evolution of influenza viruses during the season 2014/15 and its impact on influenza vaccine effectiveness in primary care in Austria as estimated by a test-negative case control design. VE estimates were performed for each influenza virus type/subtype, stratified by underlying diseases and adjusted for age, sex and calendar week of infection. Results Detailed genetic and antigenic analyses showed that circulating A(H3N2) viruses were genetically distinct from the 2014/15 A(H3N2) vaccine component indicating a profound vaccine mismatch. The Influenza A(H1N1)pdm09 viruses were antigenically conserved and matched the respective vaccine component. Influenza B viruses were lineage-matched B/Yamagata viruses with a clade-level variation. Consistent with substantial vaccine mismatch for the A(H3N2) viruses a crude overall VE of only 47% was estimated, whereas the VE estimates for A(H1N1)pdm09 were 84% and for influenza B viruses 70%. Increased VE estimates were obtained after stratification by underlying diseases and adjustment for the covariates sex and age, whereby the adjustment for the calendar week of infection was the covariate exerting the highest influence on adjusted VE estimates. Conclusion In summary, VE data obtained in this study underscore the importance to perform VE estimates in the context of detailed characterization of the contributing viruses and also demonstrate that the calendar week of influenza virus infection is the most important confounder of VE estimates. PMID:26975056

  6. Biology and transmission of avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The natural host and reservoir for avian influenza is in wild birds where the viral infection is typically asymptomatic. The virus primarily replicates in the enteric tract and transmission is thought to be primarily by fecal-oral transmission. Avian influenza can infect a broad host range, but fo...

  7. A brief introduction to avian influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) causes a disease of high economic importance for poultry production worldwide. The earliest recorded cases of probable high pathogenicity AIV in poultry were reported in Italy in the 1870’s and avian influenza been recognized in domestic poultry through the modern era of ...

  8. Emergence of a novel swine-origin influenza A virus (S-OIV) H1N1 virus in humans

    PubMed Central

    Peiris, JS Malik; Poon, Leo LM; Guan, Yi

    2016-01-01

    A recently emerged novel influenza A H1N1 virus continues to spread globally. The virus contains a novel constellation of gene segments, the nearest known precursors being viruses found in swine and it likely arose through reassortment of two or more viruses of swine origin. H1N1, H1N2 and H3N2 subtype swine influenza viruses have occasionally infected humans before but such zoonotic transmission-events did not lead to sustained human-to-human transmission in the manner this swine-origin influenza virus (S-OIV) has done. Its transmission among humans appears to be higher than that observed with seasonal influenza. Children and young adults appear to those most affected and also those who appear to maintain transmission. Clinical disease generally appears mild but complications leading to hospitalization can occur, especially in those with underlying lung or cardiac disease, diabetes or those on immunosuppresive therapies. There are concerns that the virus may reassort with existing human influenza virus giving rise to more transmissible or more pathogenic viruses. The virus appears to retain the potential to transmit back to swine and thus continued reassortment with swine viruses is a cause for concern. PMID:19540800

  9. Antigenic characterization of an H3N2 swine influenza virus isolated from pigs with proliferative and necrotizing pneumonia in Quebec.

    PubMed Central

    Bikour, M H; Cornaglia, E; Weber, J M; Elazhary, Y

    1994-01-01

    A new strain of swine influenza A virus, designated A/Swine/Saint-Hyacinthe/150/90 has been isolated from pigs with severe proliferative and necrotizing pneumonia in Quebec. The antigenic characterization of the hemagglutinin was performed by hemagglutination inhibition test, immunoblot and indirect immunoprecipitation using polyclonal antisera. Only the last test was able to detect an antigenic relationship between the hemagglutinin of this isolate and an H3 subtype influenza virus. The immunoprecipitation test was a useful alternative for determining the hemagglutinin of influenza A virus subtypes. The neuraminidase inhibition test demonstrated a reactivity between the A/Swine/Saint-Hyacinthe/150/90 and antiserum against a N2 subtype influenza virus. Our results indicate that this new strain isolated for the first time in the porcine population of Canada is related to A/Sw/Hong Kong/76 H3N2 swine influenza virus. Images Fig. 1. Fig. 2. PMID:7889461

  10. Isolation and genetic characterization of avian influenza viruses and a Newcastle disease virus from wild birds in Barbados: 2003-2004.

    PubMed

    Douglas, Kirk O; Lavoie, Marc C; Kim, L Mia; Afonso, Claudio L; Suarez, David L

    2007-09-01

    Zoonotic transmission of an H5N1 avian influenza A virus to humans in 2003-present has generated increased public health and scientific interest in the prevalence and variability of influenza A viruses in wild birds and their potential threat to human health. Migratory waterfowl and shorebirds are regarded as the primordial reservoir of all influenza A viral subtypes and have been repeatedly implicated in avian influenza outbreaks in domestic poultry and swine. All of the 16 hemagglutinin and nine neuraminidase influenza subtypes have been isolated from wild birds, but waterfowl of the order Anseriformes are the most commonly infected. Using 9-to-11-day-old embryonating chicken egg culture, virus isolation attempts were conducted on 168 cloacal swabs from various resident, imported, and migratory bird species in Barbados during the months of July to October of 2003 and 2004. Hemagglutination assay and reverse transcription-polymerase chain reaction were used to screen all allantoic fluids for the presence of hemagglutinating agents and influenza A virus. Hemagglutination positive-influenza negative samples were also tested for Newcastle disease virus (NDV), which is also found in waterfowl. Two influenza A viruses and one NDV were isolated from Anseriformes (40/168), with isolation rates of 5.0% (2/40) and 2.5% (1/40), respectively, for influenza A and NDV. Sequence analysis of the influenza A virus isolates showed them to be H4N3 viruses that clustered with other North American avian influenza viruses. This is the first report of the presence of influenza A virus and NDV in wild birds in the English-speaking Caribbean. PMID:17992942

  11. Influenza vaccine effectiveness estimates in Europe in a season with three influenza type/subtypes circulating: the I-MOVE multicentre case-control study, influenza season 2012/13.

    PubMed

    Kissling, E; Valenciano, M; Buchholz, U; Larrauri, A; Cohen, J M; Nunes, B; Rogalska, J; Pitigoi, D; Paradowska-Stankiewicz, I; Reuss, A; Jiménez-Jorge, S; Daviaud, I; Guiomar, R; O'Donnell, J; Necula, G; Głuchowska, M; Moren, A

    2014-01-01

    In the fifth season of Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE), we undertook a multicentre case-control study (MCCS) in seven European Union (EU) Member States to measure 2012/13 influenza vaccine effectiveness against medically attended influenza-like illness (ILI) laboratory confirmed as influenza. The season was characterised by substantial co-circulation of influenza B, A(H1N1)pdm09 and A(H3N2) viruses. Practitioners systematically selected ILI patients to swab ≤7 days of symptom onset. We compared influenza-positive by type/subtype to influenza-negative patients among those who met the EU ILI case definition. We conducted a complete case analysis using logistic regression with study as fixed effect and calculated adjusted vaccine effectiveness (AVE), controlling for potential confounders (age, sex, symptom onset week and presence of chronic conditions). We calculated AVE by type/subtype. Study sites sent 7,954 ILI/acute respiratory infection records for analysis. After applying exclusion criteria, we included 4,627 ILI patients in the analysis of VE against influenza B (1,937 cases), 3,516 for A(H1N1)pdm09 (1,068 cases) and 3,340 for influenza A(H3N2) (730 cases). AVE was 49.3% (95% confidence interval (CI): 32.4 to 62.0) against influenza B, 50.4% (95% CI: 28.4 to 65.6) against A(H1N1)pdm09 and 42.2% (95% CI: 14.9 to 60.7) against A(H3N2). Our results suggest an overall low to moderate AVE against influenza B, A(H1N1)pdm09 and A(H3N2), between 42 and 50%. In this season with many co-circulating viruses, the high sample size enabled stratified AVE by type/subtype. The low estimates indicate seasonal influenza vaccines should be improved to achieve acceptable protection levels. PMID:24556348

  12. Ultrasensitive detection of influenza viruses with a glycan-based impedimetric biosensor.

    PubMed

    Hushegyi, András; Pihíková, Dominika; Bertok, Tomas; Adam, Vojtech; Kizek, René; Tkac, Jan

    2016-05-15

    An ultrasensitive impedimetric glycan-based biosensor for reliable and selective detection of inactivated, but intact influenza viruses H3N2 was developed. Such glycan-based approach has a distinct advantage over antibody-based detection of influenza viruses since glycans are natural viral receptors with a possibility to selectively distinguish between potentially pathogenic influenza subtypes by the glycan-based biosensors. Build-up of the biosensor was carefully optimized with atomic force microscopy applied for visualization of the biosensor surface after binding of viruses with the topology of an individual viral particle H3N2 analyzed. The glycan biosensor could detect a glycan binding lectin with a limit of detection (LOD) of 5 aM. The biosensor was finally applied for analysis of influenza viruses H3N2 with LOD of 13 viral particles in 1 μl, what is the lowest LOD for analysis of influenza viral particles by the glycan-based device achieved so far. The biosensor could detect H3N2 viruses selectively with a sensitivity ratio of 30 over influenza viruses H7N7. The impedimetric biosensor presented here is the most sensitive glycan-based device for detection of influenza viruses and among the most sensitive antibody or aptamer based biosensor devices. PMID:26765527

  13. Environmental role in influenza virus outbreaks.

    PubMed

    Sooryanarain, Harini; Elankumaran, Subbiah

    2015-01-01

    The environmental drivers of influenza outbreaks are largely unknown. Despite more than 50 years of research, there are conflicting lines of evidence on the role of the environment in influenza A virus (IAV) survival, stability, and transmissibility. With the increasing and looming threat of pandemic influenza, it is important to understand these factors for early intervention and long-term control strategies. The factors that dictate the severity and spread of influenza would include the virus, natural and acquired hosts, virus-host interactions, environmental persistence, virus stability and transmissibility, and anthropogenic interventions. Virus persistence in different environments is subject to minor variations in temperature, humidity, pH, salinity, air pollution, and solar radiations. Seasonality of influenza is largely dictated by temperature and humidity, with cool-dry conditions enhancing IAV survival and transmissibility in temperate climates in high latitudes, whereas humid-rainy conditions favor outbreaks in low latitudes, as seen in tropical and subtropical zones. In mid-latitudes, semiannual outbreaks result from alternating cool-dry and humid-rainy conditions. The mechanism of virus survival in the cool-dry or humid-rainy conditions is largely determined by the presence of salts and proteins in the respiratory droplets. Social determinants of heath, including health equity, vaccine acceptance, and age-related illness, may play a role in influenza occurrence and spread. PMID:25422855

  14. Oral fluids as a live-animal sample for evaluating cross-reactivity and cross-protection following intranasal influenza A virus vaccination in pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In North American swine there are numerous antigenically distinct influenza A virus (IAV) H1 subtypes currently circulating, making vaccine development difficult due to the inability to formulate a vaccine that provides broad cross-protection. Live-attenuated influenza virus (LAIV) vaccines provide ...

  15. Transcriptional analysis of the innate immune response of ducks to different species-of-origin low pathogenic H7 avian influenza viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Ducks represent an important reservoir for avian influenza (AI) viruses and are partly responsible for the worldwide dissemination of AI. Due to the ability of some low pathogenicity avian influenza viruses (LPAIV) of the hemagglutinin H7 subtype to mutate into a highly pathogenic form o...

  16. Influenza vaccine effectiveness in Italy: Age, subtype-specific and vaccine type estimates 2014/15 season.

    PubMed

    Rizzo, Caterina; Bella, Antonino; Alfonsi, Valeria; Puzelli, Simona; Palmieri, Anna Pina; Chironna, Maria; Pariani, Elena; Piatti, Alessandra; Tiberti, Donatella; Ghisetti, Valeria; Rangoni, Roberto; Colucci, Maria Eugenia; Affanni, Paola; Germinario, Cinzia; Castrucci, Maria Rita

    2016-06-01

    The 2014/15 influenza season in Europe was characterised by the circulation of influenza A(H3N2) viruses with an antigenic and genetic mismatch from the vaccine strain A/Texas/50/2012(H3N2) recommended for the Northern hemisphere for the 2014/15 season. Italy, differently from other EU countries where most of the subtyped influenza A viruses were H3N2, experienced a 2014/15 season characterized by an extended circulation of two influenza viruses: A(H1N1)pdm09 and A(H3N2), that both contributed substantially to morbidity. Within the context of the existing National sentinel influenza surveillance system (InfluNet) a test-negative case-control study was established in order to produce vaccine effectiveness (VE) estimates. The point estimates VE were adjusted by age group (<5; 5-15; 15-64; 65+ years), the presence of at least one chronic condition, target group for vaccination and need help for walking or bathing. In Italy, adjusted estimates of the 2014/15 seasonal influenza VE against medically attended influenza-like illness (ILI) laboratory-confirmed as influenza for all age groups were 6.0% (95%CI: -36.5 to 35.2%), 43.6% (95%CI: -3.7 to 69.3%), -84.5% (95%CI: (-190.4 to -17.2%) and 50.7% (95% CI: -2.5 to 76.3%) against any influenza virus, A(H1N1)pdm09, A(H3N2) and B, respectively. These results suggest evidence of good VE against A(H1N1)pdm09 and B viruses in Italy and evidence of lack of VE against A(H3N2) virus due to antigenic and genetic mismatch between circulating A(H3N2) and the respective 2014/15 vaccine strain. PMID:27154392

  17. Structural basis of influenza virus neutralization

    PubMed Central

    Han, Thomas; Marasco, Wayne A.

    2010-01-01

    Although seasonal influenza vaccines play a valuable role in reducing the spread of the virus at the population level, ongoing viral evolution to evade immune responses remains problematic. No current vaccines are likely to elicit enduring protection in the face of emerging and re-emerging influenza viruses that rapidly undergoing antigenic drift. Eliciting broadly cross-neutralizing antibody responses against influenza virus is a crucial goal for seasonal and pandemic influenza vaccine preparation. Recent three-dimensional structure information obtained from crystallization of influenza antigens in complex with neutralizing antibodies (nAbs) have provided a framework for interpreting antibody-based viral neutralization that should aid in the design of vaccine immunogens. Here, we will review current knowledge of the structure-based mechanisms contributing to the neutralization and neutralization escape of influenza viruses. We will also explore the potential for this structure-based approach to overcome the challenge of obtaining the highly desired “universal” influenza vaccine. PMID:21251008

  18. Targets for the Induction of Protective Immunity Against Influenza A Viruses

    PubMed Central

    Bodewes, Rogier; Osterhaus, Albert D.M.E; Rimmelzwaan, Guus F.

    2010-01-01

    The current pandemic caused by the new influenza A(H1N1) virus of swine origin and the current pandemic threat caused by the highly pathogenic avian influenza A viruses of the H5N1 subtype have renewed the interest in the development of vaccines that can induce broad protective immunity. Preferably, vaccines not only provide protection against the homologous strains, but also against heterologous strains, even of another subtype. Here we describe viral targets and the arms of the immune response involved in protection against influenza virus infections such as antibodies directed against the hemagglutinin, neuraminidase and the M2 protein and cellular immune responses directed against the internal viral proteins. PMID:21994606

  19. Exploring the antigenic relatedness of influenza virus haemagglutinins with strain-specific polyclonal antibodies.

    PubMed

    García-Barreno, Blanca; Delgado, Teresa; Benito, Sonia; Casas, Inmaculada; Pozo, Francisco; Melero, José A

    2014-10-01

    Alternative methods to the standard haemagglutination inhibition (HI) and neutralization tests to probe the antigenic properties of the influenza virus haemagglutinin (HA) were developed in this study. Vaccinia virus recombinants expressing reference HAs were used to immunize rabbits from which polyclonal antibodies were obtained. These antibodies were subtype specific but showed limited intra-subtype strain specificity in ELISA. The discriminatory capacity of these antibodies was, however, markedly increased after adsorption to cells infected with heterologous influenza viruses, revealing antigenic differences that were otherwise undistinguishable by standard HI and neutralization tests. Furthermore, the unadsorbed antibodies could be used to select escape mutants of the reference strain, which after sequencing unveiled amino acid changes responsible of the noted antigenic differences. These procedures therefore provide alternative methods for the antigenic characterization of influenza HA and might be useful in studies of HA antigenic evolution. PMID:25000959

  20. Innate immune evasion strategies of influenza viruses

    PubMed Central

    Hale, Benjamin G; Albrecht, Randy A; García-Sastre, Adolfo

    2010-01-01

    Influenza viruses are globally important human respiratory pathogens. These viruses cause seasonal epidemics and occasional worldwide pandemics, both of which can vary significantly in disease severity. The virulence of a particular influenza virus strain is partly determined by its success in circumventing the host immune response. This article briefly reviews the innate mechanisms that host cells have evolved to resist virus infection, and outlines the plethora of strategies that influenza viruses have developed in order to counteract such powerful defences. The molecular details of this virus–host interplay are summarized, and the ways in which research in this area is being applied to the rational design of protective vaccines and novel antivirals are discussed. PMID:20020828

  1. Proposed reference sequences for hepatitis E virus subtypes.

    PubMed

    Smith, Donald B; Simmonds, Peter; Izopet, Jacques; Oliveira-Filho, Edmilson F; Ulrich, Rainer G; Johne, Reimar; Koenig, Matthias; Jameel, Shahid; Harrison, Tim J; Meng, Xiang-Jin; Okamoto, Hiroaki; Van der Poel, Wim H M; Purdy, Michael A

    2016-03-01

    The nomenclature of hepatitis E virus (HEV) subtypes is inconsistent and makes comparison of different studies problematic. We have provided a table of proposed complete genome reference sequences for each subtype. The criteria for subtype assignment vary between different genotypes and methodologies, and so a conservative pragmatic approach has been favoured. Updates to this table will be posted on the International Committee on Taxonomy of Viruses website (http://talk.ictvonline.org/r.ashx?C). The use of common reference sequences will facilitate communication between researchers and help clarify the epidemiology of this important human pathogen. This subtyping procedure might be adopted for other taxa of the genus Orthohepevirus. PMID:26743685

  2. Characterization of A/eq-1 virus isolated during the equine influenza epidemic in India.

    PubMed

    Singh, G

    1994-02-01

    The equine influenza virus, Ludhiana/5/87, isolated from the clinical material during the epidemic of equine influenza in India in 1987 was inhibited in haemagglutination-inhibition test by the antiserum against the prototype A/eq/Prague/1/56 (H7N7) virus and by post-epidemic horse sera. In haemagglutinin and neuraminidase analysis, the A/eq/Ludhiana/5/87 isolate appeared similar to the prototype A/eq/Prague/1/56 virus and was characterized as the H7N7 subtype. PMID:8067310

  3. Epidemiological and Virological Characterization of Influenza B Virus Infections.

    PubMed

    Sharabi, Sivan; Drori, Yaron; Micheli, Michal; Friedman, Nehemya; Orzitzer, Sara; Bassal, Ravit; Glatman-Freedman, Aharona; Shohat, Tamar; Mendelson, Ella; Hindiyeh, Musa; Mandelboim, Michal

    2016-01-01

    While influenza A viruses comprise a heterogeneous group of clinically relevant influenza viruses, influenza B viruses form a more homogeneous cluster, divided mainly into two lineages: Victoria and Yamagata. This divergence has complicated seasonal influenza vaccine design, which traditionally contained two seasonal influenza A virus strains and one influenza B virus strain. We examined the distribution of the two influenza B virus lineages in Israel, between 2011-2014, in hospitalized and in non-hospitalized (community) influenza B virus-infected patients. We showed that influenza B virus infections can lead to hospitalization and demonstrated that during some winter seasons, both influenza B virus lineages circulated simultaneously in Israel. We further show that the influenza B virus Yamagata lineage was dominant, circulating in the county in the last few years of the study period, consistent with the anti-Yamagata influenza B virus antibodies detected in the serum samples of affected individuals residing in Israel in the year 2014. Interestingly, we found that elderly people were particularly vulnerable to Yamagata lineage influenza B virus infections. PMID:27533045

  4. Epidemiological and Virological Characterization of Influenza B Virus Infections

    PubMed Central

    Sharabi, Sivan; Drori, Yaron; Micheli, Michal; Friedman, Nehemya; Orzitzer, Sara; Bassal, Ravit; Glatman-Freedman, Aharona; Shohat, Tamar; Mendelson, Ella; Hindiyeh, Musa; Mandelboim, Michal

    2016-01-01

    While influenza A viruses comprise a heterogeneous group of clinically relevant influenza viruses, influenza B viruses form a more homogeneous cluster, divided mainly into two lineages: Victoria and Yamagata. This divergence has complicated seasonal influenza vaccine design, which traditionally contained two seasonal influenza A virus strains and one influenza B virus strain. We examined the distribution of the two influenza B virus lineages in Israel, between 2011–2014, in hospitalized and in non-hospitalized (community) influenza B virus-infected patients. We showed that influenza B virus infections can lead to hospitalization and demonstrated that during some winter seasons, both influenza B virus lineages circulated simultaneously in Israel. We further show that the influenza B virus Yamagata lineage was dominant, circulating in the county in the last few years of the study period, consistent with the anti-Yamagata influenza B virus antibodies detected in the serum samples of affected individuals residing in Israel in the year 2014. Interestingly, we found that elderly people were particularly vulnerable to Yamagata lineage influenza B virus infections. PMID:27533045

  5. Evolution of highly pathogenic avian influenza H5N1 viruses in Egypt indicating progressive adaptation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was first diagnosed in poultry in Egypt in 2006, and since then the disease became enzootic in poultry throughout the country affecting the poultry industry and village poultry as well as infecting humans. Vaccination has been used ...

  6. The evolutionary genetics and emergence of avian influenza viruses in wild birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We surveyed the genetic diversity of avian influenza virus (AIV) in wild birds, comprising 167 complete viral genomes sampled from 14 bird species in four locations across North America. This revealed 29 combinations of hemagglutinin (HA) and neuraminidase (NA) subtypes, with 26% of isolates showin...

  7. Avian influenza virus with Hemagglutinin-Neuraminidase combination H8N8, isolated in Russia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study reports the genome sequence of an avian influenza virus (AIV) subtype H8N8 isolated in Russia. The genome analysis shows that all genes belong to AIV Eurasian lineages. The PB2 gene was similar to a Mongolian low pathogenic (LP) AIV H7N1 and a Chinese high pathogenic (HP) AIV H5N2....

  8. Electronic microarray assays for avian influenza and Newcastle disease virus.

    PubMed

    Lung, Oliver; Beeston, Anne; Ohene-Adjei, Samuel; Pasick, John; Hodko, Dalibor; Hughes, Kimberley Burton; Furukawa-Stoffer, Tara; Fisher, Mathew; Deregt, Dirk

    2012-11-01

    Microarrays are suitable for multiplexed detection and typing of pathogens. Avian influenza virus (AIV) is currently classified into 16 H (hemagglutinin) and 9 N (neuraminidase) subtypes, whereas Newcastle disease virus (NDV) strains differ in virulence and are broadly classified into high and low pathogenicity types. In this study, three assays for detection and typing of poultry viruses were developed on an automated microarray platform: a multiplex assay for simultaneous detection of AIV and detection and pathotyping of NDV, and two separate assays for differentiating all AIV H and N subtypes. The AIV-NDV multiplex assay detected all strains in a 63 virus panel, and accurately typed all high pathogenicity NDV strains tested. A limit of detection of 10(1)-10(3) TCID(50)/mL and 200-400 EID(50)/mL was obtained for NDV and AIV, respectively. The AIV typing assays accurately typed all 41 AIV strains and a limit of detection of 4-200 EID(50)/mL was obtained. Assay validation showed that the microarray assays were generally comparable to real-time RT-PCR. However, the AIV typing microarray assays detected more positive clinical samples than the AIV matrix real-time RT-PCR, and also provided information regarding the subtype. The AIV-NDV multiplex and AIV H typing microarray assays detected mixed infections and could be useful for detection and typing of AIV and NDV. PMID:22796283

  9. Induction of a Protective Heterosubtypic Immune Response Against the Influenza Virus by using Recombinant Adenoviral Vectors Expressing Hemagglutinin of the Influenza H5 Virus.

    PubMed

    Shmarov, M M; Sedova, E S; Verkhovskaya, L V; Rudneva, I A; Bogacheva, E A; Barykova, Yu A; Shcherbinin, D N; Lysenko, A A; Tutykhina, I L; Logunov, D Y; Smirnov, Yu A; Naroditsky, B S; Gintsburg, A L

    2010-04-01

    Influenza viruses are characterized by a high degree of antigenic variability, which causes the annual emergence of flu epidemics and irregularly timed pandemics caused by viruses with new antigenic and biological traits. Novel approaches to vaccination can help circumvent this problem. One of these new methods incorporates genetic vaccines based on adenoviral vectors. Recombinant adenoviral vectors which contain hemagglutinin-encoding genes from avian H5N1 and H5N2 (Ad-HA5-1 and Ad-HA5-2) influenza viruses were obtained using the AdEasy Adenoviral Vector System (Stratagene). Laboratory mice received a double intranasal vaccination with Ad-HA5-1 and Ad-HA5-2. This study demonstrates that immunization with recombinant adenoviruses bearing the Н 5 influenza virus hemagglutinin gene induces a immune response which protects immunized mice from a lethal dose of the H5 influenza virus. Moreover, it also protects the host from a lethal dose of the H1 virus, which belongs to the same clade as H5, but does not confer protection from the subtype H3 influenza virus, which belongs to a different clade. PMID:22649637

  10. Avian Influenza A (H7N9) Virus

    MedlinePlus

    ... this page: About CDC.gov . Avian Influenza H5 Viruses in the United States Updates and Publications Information ... Humans Examples of Human Infections with Avian Influenza Viruses Outbreaks Health Care and Laboratorian Guidance HPAI A ...

  11. Prevention and Treatment of Avian Influenza A Viruses in People

    MedlinePlus

    ... Research Making a Candidate Vaccine Virus Related Links Influenza Types Seasonal Avian Swine Variant Pandemic Other Get ... Button Past Newsletters Prevention and Treatment of Avian Influenza A Viruses in People Language: English Español ...

  12. DIESEL EXHAUST ENHANCES INFLUENZA VIRUS INFECTIONS IN RESPIRATORY EPITHELIAL CELLS

    EPA Science Inventory

    Several factors, such as age and nutritional status can affect the susceptibility to influenza infections. Moreover, exposure to air pollutants, such as diesel exhaust (DE), has been shown to affect respiratory virus infections in rodent models. Influenza virus primarily infects ...

  13. The Genetic Diversity of Influenza A Viruses in Wild Birds in Peru

    PubMed Central

    Nelson, Martha I.; Pollett, Simon; Ghersi, Bruno; Silva, Maria; Simons, Mark P.; Icochea, Eliana; Gonzalez, Armando E.; Segovia, Karen; Kasper, Matthew R.; Montgomery, Joel M.; Bausch, Daniel G.

    2016-01-01

    Our understanding of the global ecology of avian influenza A viruses (AIVs) is impeded by historically low levels of viral surveillance in Latin America. Through sampling and whole-genome sequencing of 31 AIVs from wild birds in Peru, we identified 10 HA subtypes (H1-H4, H6-H7, H10-H13) and 8 NA subtypes (N1-N3, N5-N9). The majority of Peruvian AIVs were closely related to AIVs found in North America. However, unusual reassortants, including a H13 virus containing a PA segment related to extremely divergent Argentinian viruses, suggest that substantial AIV diversity circulates undetected throughout South America. PMID:26784331

  14. Detection of Evolutionarily Distinct Avian Influenza A Viruses in Antarctica

    PubMed Central

    Vijaykrishna, Dhanasekaran; Butler, Jeffrey; Baas, Chantal; Maurer-Stroh, Sebastian; Silva-de-la-Fuente, M. Carolina; Medina-Vogel, Gonzalo; Olsen, Bjorn; Kelso, Anne; Barr, Ian G.; González-Acuña, Daniel

    2014-01-01

    ABSTRACT Distinct lineages of avian influenza viruses (AIVs) are harbored by spatially segregated birds, yet significant surveillance gaps exist around the globe. Virtually nothing is known from the Antarctic. Using virus culture, molecular analysis, full genome sequencing, and serology of samples from Adélie penguins in Antarctica, we confirmed infection by H11N2 subtype AIVs. Their genetic segments were distinct from all known contemporary influenza viruses, including South American AIVs, suggesting spatial separation from other lineages. Only in the matrix and polymerase acidic gene phylogenies did the Antarctic sequences form a sister relationship to South American AIVs, whereas distant phylogenetic relationships were evident in all other gene segments. Interestingly, their neuraminidase genes formed a distant relationship to all avian and human influenza lineages, and the polymerase basic 1 and polymerase acidic formed a sister relationship to the equine H3N8 influenza virus lineage that emerged during 1963 and whose avian origins were previously unknown. We also estimated that each gene segment had diverged for 49 to 80 years from its most closely related sequences, highlighting a significant gap in our AIV knowledge in the region. We also show that the receptor binding properties of the H11N2 viruses are predominantly avian and that they were unable to replicate efficiently in experimentally inoculated ferrets, suggesting their continuous evolution in avian hosts. These findings add substantially to our understanding of both the ecology and the intra- and intercontinental movement of Antarctic AIVs and highlight the potential risk of an incursion of highly pathogenic AIVs into this fragile environment. PMID:24803521

  15. Age-specific epidemic waves of influenza and respiratory syncytial virus in a subtropical city.

    PubMed

    Yang, Lin; Chan, Kwok Hung; Suen, Lorna K P; Chan, King Pan; Wang, Xiling; Cao, Peihua; He, Daihai; Peiris, J S Malik; Wong, Chit Ming

    2015-01-01

    Both influenza and respiratory syncytial virus (RSV) are active throughout the year in subtropical or tropical regions, but few studies have reported on age-specific seasonal patterns of these viruses. We examined the age-specific epidemic curves of laboratory-confirmed cases of influenza A (subtyped into seasonal A(H1N1), A(H3N2), and pandemic virus A(H1N1)pdm09), influenza B and respiratory syncytial virus (RSV), in subtropical city Hong Kong from 2004 to 2013. We found that different types and subtypes of influenza showed similar two-peak patterns across age groups, with one peak in winter and another in spring/summer. Age differences were found in epidemic onset time and duration, but none could reach statistical significance (p > 0.05). Age synchrony was found in epidemic peak time for both cool and warm seasons. RSV showed less clear seasonal patterns and non-synchronized epidemic curves across age. In conclusion, age synchrony was found in influenza seasonal epidemics and the 2009 pandemic, but not in RSV. None of the age groups consistently appear as the driving force for seasonal epidemics of influenza and RSV in Hong Kong. PMID:25981824

  16. Sialylated immunoglobulin G can neutralize influenza virus infection through receptor mimicry

    PubMed Central

    Zhao, Conghui; Liu, Xingmu; Zhang, Zaiping; Li, Tongfei; Sun, Ruiman; Gu, Huan; Gu, Jiang

    2016-01-01

    Influenza viruses possess a great threat to human health, but there is still no effective drug to deal with the outbreak of possible new influenza subtypes. In this study, we first fractionated sialylated immunoglobulin G (IgG), mainly Fab sialylated fraction, with sambucus nigra agglutinin affinity chromatography. We then demonstrated that sialylated IgG possessed more effective neutralizing activity against 2009 A (H1N1) subtype than that of IgG mixture, and sialosides on the Fab is crucial in this neutralization reaction as when such residues were removed with neuraminidase A digestion the blocking effect was significantly reduced. It appears that sialic acid residues attached to Fab could serve as binding moieties to receptor binding site of influenza virus. These findings indicate that sialylated IgG probably is an effective anti-influenza broad-spectrum drug utilizing its receptor mimicry to competitively inhibit the attachment of influenza viruses with sialic acid receptors on target cells. This property would be particularly useful if it can be applied to prevent newly emerged influenza virus strain infections in future epidemics. PMID:26870994

  17. Sialylated immunoglobulin G can neutralize influenza virus infection through receptor mimicry.

    PubMed

    Huang, Tao; Chen, Xueling; Zhao, Conghui; Liu, Xingmu; Zhang, Zaiping; Li, Tongfei; Sun, Ruiman; Gu, Huan; Gu, Jiang

    2016-03-29

    Influenza viruses possess a great threat to human health, but there is still no effective drug to deal with the outbreak of possible new influenza subtypes. In this study, we first fractionated sialylated immunoglobulin G (IgG), mainly Fab sialylated fraction, with sambucus nigra agglutinin affinity chromatography. We then demonstrated that sialylated IgG possessed more effective neutralizing activity against 2009 A (H1N1) subtype than that of IgG mixture, and sialosides on the Fab is crucial in this neutralization reaction as when such residues were removed with neuraminidase A digestion the blocking effect was significantly reduced. It appears that sialic acid residues attached to Fab could serve as binding moieties to receptor binding site of influenza virus. These findings indicate that sialylated IgG probably is an effective anti-influenza broad-spectrum drug utilizing its receptor mimicry to competitively inhibit the attachment of influenza viruses with sialic acid receptors on target cells. This property would be particularly useful if it can be applied to prevent newly emerged influenza virus strain infections in future epidemics. PMID:26870994

  18. Comparative pathology of select agent influenza A virus infections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus infections may spread rapidly in human populations and cause acute respiratory disease with variable mortality. Two of these influenza viruses have been designated as select agents because of the high case fatality rate: 1918 H1N1 virus and highly pathogenic avian influenza (HPAI) ...

  19. WOULD THE 1918 PANDEMIC INFLUENZA VIRUS BE A THREAT TODAY?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 1918 influenza pandemic caused more than 20 million deaths worldwide. Under biosafety level 3Ag containment, a recombinant influenza virus bearing the 1918 influenza virus hemagglutinin (HA) and neuraminidase (NA) was generated. This virus is highly virulent in mice, pointing to the 1918 HA and...

  20. Respiratory Viruses Other than Influenza Virus: Impact and Therapeutic Advances

    PubMed Central

    Nichols, W. Garrett; Peck Campbell, Angela J.; Boeckh, Michael

    2008-01-01

    Summary: Though several antivirals have been developed and marketed to treat influenza virus infections, the development of antiviral agents with clinical activity against other respiratory viruses has been more problematic. Here we review the epidemiology of respiratory viral infections in immunocompetent and immunocompromised hosts, examine the evidence surrounding the currently available antivirals for respiratory viral infections other than influenza, highlight those that are in the pipeline, and discuss the hurdles for development of such agents. PMID:18400797

  1. Detection and Isolation of H5N1 Influenza virus from Large Volumes of Natural Water

    PubMed Central

    Khalenkov, Alexey; Laver, W. Graeme; Webster, Robert G.

    2009-01-01

    Various species of aquatic or wetlands birds can be the natural reservoir of avian influenza A viruses of all hemagglutinin (HA) subtypes. Shedding of the virus into water leads to transmission between waterfowl and is a major threat for epidemics in poultry and pandemics in humans. Concentrations of the influenza virus in natural water reservoirs are often too low to be detected by most methods. The procedure was designed to detect low concentrations of the influenza virus in large volumes of water without the need for costly installations and reagents. The virus was adsorbed onto formalin-fixed erythrocytes and subsequently isolated in chicken embryos. Sensitivity of the method was determined using a reverse-genetic H5N1 virus. A concentration as low as 0.03 of the 50% egg infection dose per milliliter (EID50/ml) of the initial volume of water was effectively detected. The probability of detection was ∼13%, which is comparable to that of detecting the influenza virus M-gene by PCR amplification. The method can be used by field workers, ecologists, ornithologists, and researchers who need a simple method to isolate H5N1 influenza virus from natural reservoirs. The detection and isolation of virus in embryonated chicken eggs may help epidemiologic, genetic, and vaccine studies. PMID:18325605

  2. A new class of synthetic anti-lipopolysaccharide peptides inhibits influenza A virus replication by blocking cellular attachment.

    PubMed

    Hoffmann, Julia; Schneider, Carola; Heinbockel, Lena; Brandenburg, Klaus; Reimer, Rudolph; Gabriel, Gülsah

    2014-04-01

    Influenza A viruses are a continuous threat to human health as illustrated by the 2009 H1N1 pandemic. Since circulating influenza virus strains become increasingly resistant against currently available drugs, the development of novel antivirals is urgently needed. Here, we have evaluated a recently described new class of broad-spectrum antiviral peptides (synthetic anti-lipopolysaccharide peptides; SALPs) for their potential to inhibit influenza virus replication in vitro and in vivo. We found that particularly SALP PEP 19-2.5 shows high binding affinities for the influenza virus receptor molecule, N-Acetylneuraminic acid, leading to impaired viral attachment and cellular entry. As a result, replication of several influenza virus subtypes (H7N7, H3N2 and 2009 pandemic H1N1) was strongly reduced. Furthermore, mice co-treated with PEP 19-2.5 were protected against an otherwise 100% lethal H7N7 influenza virus infection. These findings show that SALPs exhibit antiviral activity against influenza viruses by blocking virus attachment and entry into host cells. Thus, SALPs present a new class of broad-spectrum antiviral peptides for further development for influenza virus therapy. PMID:24486207

  3. Broadly neutralizing antibodies against influenza viruses

    PubMed Central

    Laursen, Nick S.; Wilson, Ian A.

    2014-01-01

    Despite available antivirals and vaccines, influenza infections continue to be a major cause of mortality worldwide. Vaccination generally induces an effective, but strain-specific antibody response. As the virus continually evolves, new vaccines have to be administered almost annually when a novel strain becomes dominant. Furthermore, the sporadic emerging resistance to neuraminidase inhibitors among circulating strains suggests an urgent need for new therapeutic agents. Recently, several cross-reactive antibodies have been described, which neutralize an unprecedented spectrum of influenza viruses. These broadly neutralizing antibodies generally target conserved functional regions on the major influenza surface glycoprotein hemagglutinin (HA). The characterization of their neutralization breadth and epitopes on HA could stimulate the development of new antibody-based antivirals and broader influenza vaccines. PMID:23583287

  4. Influenza A virus transmission via respiratory aerosols or droplets as it relates to pandemic potential.

    PubMed

    Richard, Mathilde; Fouchier, Ron A M

    2016-01-01

    Many respiratory viruses of humans originate from animals. For instance, there are now eight paramyxoviruses, four coronaviruses and four orthomxoviruses that cause recurrent epidemics in humans but were once confined to other hosts. In the last decade, several members of the same virus families have jumped the species barrier from animals to humans. Fortunately, these viruses have not become established in humans, because they lacked the ability of sustained transmission between humans. However, these outbreaks highlighted the lack of understanding of what makes a virus transmissible. In part triggered by the relatively high frequency of occurrence of influenza A virus zoonoses and pandemics, the influenza research community has started to investigate the viral genetic and biological traits that drive virus transmission via aerosols or respiratory droplets between mammals. Here we summarize recent discoveries on the genetic and phenotypic traits required for airborne transmission of zoonotic influenza viruses of subtypes H5, H7 and H9 and pandemic viruses of subtypes H1, H2 and H3. Increased understanding of the determinants and mechanisms of respiratory virus transmission is not only key from a basic scientific perspective, but may also aid in assessing the risks posed by zoonotic viruses to human health, and preparedness for such risks. PMID:26385895

  5. Identification of H2N3 influenza A viruses from swine in the United States

    PubMed Central

    Ma, Wenjun; Vincent, Amy L.; Gramer, Marie R.; Brockwell, Christy B.; Lager, Kelly M.; Janke, Bruce H.; Gauger, Phillip C.; Patnayak, Devi P.; Webby, Richard J.; Richt, Jürgen A.

    2007-01-01

    Although viruses of each of the 16 influenza A HA subtypes are potential human pathogens, only viruses of the H1, H2, and H3 subtype are known to have been successfully established in humans. H2 influenza viruses have been absent from human circulation since 1968, and as such they pose a substantial human pandemic risk. In this report, we isolate and characterize genetically similar avian/swine virus reassortant H2N3 influenza A viruses isolated from diseased swine from two farms in the United States. These viruses contained leucine at position 226 of the H2 protein, which has been associated with increased binding affinity to the mammalian α2,6Gal-linked sialic acid virus receptor. Correspondingly, the H2N3 viruses were able to cause disease in experimentally infected swine and mice without prior adaptation. In addition, the swine H2N3 virus was infectious and highly transmissible in swine and ferrets. Taken together, these findings suggest that the H2N3 virus has undergone some adaptation to the mammalian host and that their spread should be very closely monitored. PMID:18093945

  6. Characaterization of H5N1 highly pathogenic avian influenza viruses isolated from poultry in Pakistan 2006-2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nine avian influenza viruses (AIV), H5N1 subtype, were isolated from dead poultry in the Karachi region of Pakistan from 2006-2008. The intravenous pathogenicity indices and HA protein cleavage sites of all nine viruses were consistent with highly pathogenic AIV. Based on phylogenetic analysis of ...

  7. Sequence and phylogenetic analysis of H7N3 avian influenza viruses isolated from poultry in Pakistan 1995-2004

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian Influenza Viruses (AIV) are among the most prominent emerging viruses affecting animal and public health. This report was designed to explore the genetic variation, which has occurred among AIVs of the H7N3 subtype in the Northeast, Central and Southern Regions of Pakistan during the last dec...

  8. Vaccine-associated enhanced respiratory disease is influenced by hemagglutinin and neuraminidase in whole inactivated influenza virus vaccines

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple subtypes and many antigenic variants of influenza A virus (IAV) co-circulate in swine in the USA, complicating effective use of commercial vaccines to control disease and transmission. Whole inactivated virus (WIV) vaccines may provide partial protection against IAV with substantial antigen...

  9. Influenza Virus Propagation in Embryonated Chicken Eggs

    PubMed Central

    Brauer, Rena; Chen, Peter

    2015-01-01

    Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 °C and 55-60% humidity for 10 – 11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 °C, the eggs are chilled for at least 4 hr at 4 °C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 °C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed. PMID:25867050

  10. Influenza virus propagation in embryonated chicken eggs.

    PubMed

    Brauer, Rena; Chen, Peter

    2015-01-01

    Influenza infection is associated with about 36,000 deaths and more than 200,000 hospitalizations every year in the United States. The continuous emergence of new influenza virus strains due to mutation and re-assortment complicates the control of the virus and necessitates the permanent development of novel drugs and vaccines. The laboratory-based study of influenza requires a reliable and cost-effective method for the propagation of the virus. Here, a comprehensive protocol is provided for influenza A virus propagation in fertile chicken eggs, which consistently yields high titer viral stocks. In brief, serum pathogen-free (SPF) fertilized chicken eggs are incubated at 37 °C and 55-60% humidity for 10-11 days. Over this period, embryo development can be easily monitored using an egg candler. Virus inoculation is carried out by injection of virus stock into the allantoic cavity using a needle. After 2 days of incubation at 37 °C, the eggs are chilled for at least 4 hr at 4 °C. The eggshell above the air sac and the chorioallantoic membrane are then carefully opened, and the allantoic fluid containing the virus is harvested. The fluid is cleared from debris by centrifugation, aliquoted and transferred to -80 °C for long-term storage. The large amount (5-10 ml of virus-containing fluid per egg) and high virus titer which is usually achieved with this protocol has made the usage of eggs for virus preparation our favorable method, in particular for in vitro studies which require large quantities of virus in which high dosages of the same virus stock are needed. PMID:25867050

  11. A live attenuated cold adapted influenza A H7N7 candidate vaccine virus confers protection against homologous and heterologous H7 viruses in mice and ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Highly pathogenic avian influenza (HPAI) H7 subtype viruses pose a pandemic threat to humans because of their ability to transmit directly from domestic poultry to humans. The recent cases of HPAI H7 virus infection in humans underscore their pandemic potential and a need to develop a vaccine to pr...

  12. In-silico structural analysis of the influenza A subtype H7N9 neuraminidase and molecular docking with different neuraminidase inhibitors.

    PubMed

    Eweas, Ahmad F; Abdel-Moneim, Ahmed S

    2015-06-01

    Human infection with H7 influenza subtypes usually resulted in mild disease with a rare mortalities, however, human infection with the avian low pathogenic H7N9 influenza virus resulted in about 38.6 % human fatality. Due to the new cross-species barrier of this virus subtype, there is an urgent need to better understand the susceptibility to commercially available antivirals and their relation to the structural changes of the viral neuraminidase. Neuraminidases derived from 2013 H7N9, H5N1 and H1N1 were subjected to a structural analysis of their catalytic and framework binding sites. The modeling structure of selected neuraminidases from H7N9 and influenza A subtypes were solved and the docking studies with oseltamivir, zanamivir, laninamivir and peramivir were conducted. The active site residues that are responsible for both binding and cleavage of the terminally linked sialic acid receptors were found conserved. Docking studies with oseltamivir, zanamivir, laninamivir and peramivir revealed that the laninamivir and peramivir showed superior energy binding activities in comparison to the commonly used oseltamivir and zanamivir. The results presented in the current study provide data that are useful for the future treatment of different influenza A subtypes including the recently emerged H7N9. PMID:26436118

  13. Detection and typing of human-infecting influenza viruses in China by using a multiplex DNA biochip assay.

    PubMed

    Wang, Yongqiang; Qu, Jiuxin; Ba, Qi; Dong, Jiuhong; Zhang, Liang; Zhang, Hong; Wu, Aiping; Wang, Dayan; Xia, Zanxian; Peng, Daxin; Shu, Yuelong; Cao, Bin; Jiang, Taijiao

    2016-08-01

    Rapid identification of the infections of specific subtypes of influenza viruses is critical for patient treatment and pandemic control. Here we report the application of multiplex reverse transcription polymerase chain reaction (RT-PCR) coupled with membrane-based DNA biochip to the detection and discrimination of the type (A and B) and subtype (human H1N1, human H3N2, avian H5N1 and avian H7N9) of influenza viruses in circulation in China. A multiplex one-step RT-PCR assay was designed to simultaneously amplify the HA and NA genes of the four subtypes of influenza A viruses and NS genes to discriminate type A and B viruses. PCR products were analyzed by a membrane-based biochip. The analytical sensitivity of the assay was determined at a range of 2-100 copies/reactions for each of the gene transcripts. Eighty one clinical samples, containing 66 positive samples with evident seasonal influenza virus infections, were tested, which gives the clinical sensitivity and specificity of 95.5% and 100% respectively. For the avian influenza samples, 3 out of 4 H5N1 samples and 2 out of 2 H7N9 avian samples were correctly identified. We argue this method could allow a rapid, reliable and inexpensive detection and differentiation of human-infecting influenza viruses. PMID:27150046

  14. Serologic evidence of influenza A (H14) virus introduction into North America

    USGS Publications Warehouse

    Latorre-Margalef, Neus; Ramey, Andy M.; Fojtik, Alinde; Stallknecht, David E.

    2015-01-01

    Although a diverse population of influenza A viruses (IAVs) is maintained among ducks, geese, shorebirds, and gulls, not all of the 16 avian hemagglutinin (HA) subtypes are equally represented (1). The 14th HA subtype, commonly known as the H14 subtype, was historically limited to isolates from the former Soviet Union in the 1980s (2) and was not subsequently detected until 2010, when isolated in Wisconsin, USA from long-tailed ducks and a white-winged scoter (3–5). In the United States, the H14 subtype has since been isolated in California (6), Mississippi, and Texas (7); and has been reported in waterfowl in Guatemala (7). In this study, we examined whether there was serologic evidence of H14 spread among ducks in North America before (2006–2010) and after (2011–2014) the initial detection of the H14 subtype virus on this continent.

  15. Adamantane-Resistant Influenza A Viruses in the World (1902–2013): Frequency and Distribution of M2 Gene Mutations

    PubMed Central

    Dong, Guoying; Peng, Chao; Luo, Jing; Wang, Chengmin; Han, Le; Wu, Bin; Ji, Guangju; He, Hongxuan

    2015-01-01

    Adamantanes (amantadine and rimantadine) have been used to prevent and treat influenza A virus infections for many years; however, resistance to these drugs has been widely reported in the world. To investigate the frequency and distribution of M2 gene mutations in adamantane-resistant influenza variants circulated in the world between 1902 and 2013, 31251 available M2 protein sequences from different HA-subtype influenza A viruses (H1–H17) were analyzed and adamantane resistance-associated mutations were compared (L26F, V27A, A30T, A30V, S31N, G34E, and L38F). We find that 45.2% (n = 14132) of influenza A (H1–H17) viruses circulating globally were resistant to adamantanes, and the vast majority of resistant viruses (95%) bear S31N mutations. Whereas, only about 1% have V27A mutations and other mutations (L26F, A30T, G34E, and L38F) were extremely rare (their prevalence appeared to be < 0.2%). Our results confirm that H1, H3, H5, H7, H9, and H17 subtype influenza A viruses exhibit high-level resistance to adamantanes. In contrast, the appearance of adamantane-resistant mutants in H2, H4, H6, H10, and H11 subtypes was rare. However, no adamantane resistance viruses were identified among other HA subtypes (H8, H12–H16). Our findings indicate that the frequency and distribution of adamantane-resistant influenza variants varied among different HA subtypes, host species, years of isolation, and geographical areas. This comprehensive study raises concerns about the increasing prevalence of adamantane-resistant influenza A viruses and highlights the importance of monitoring the emergence and worldwide spread of adamantane-resistant variants. PMID:25768797

  16. Prevalence of influenza A viruses in livestock and free-living waterfowl in Uganda

    PubMed Central

    2014-01-01

    Background Avian influenza viruses may cause severe disease in a variety of domestic animal species worldwide, with high mortality in chickens and turkeys. To reduce the information gap about prevalence of these viruses in animals in Uganda, this study was undertaken. Results Influenza A virus prevalence by RT-PCR was 1.1% (45/4,052) while seroprevalence by ELISA was 0.8% (24/2,970). Virus prevalence was highest in domestic ducks (2.7%, 17/629) and turkeys (2.6%, 2/76), followed by free-living waterfowl (1.3%, 12/929) and swine (1.4%, 7/511). A lower proportion of chicken samples (0.4%, 7/1,865) tested positive. No influenza A virus was isolated. A seasonal prevalence of these viruses in waterfowl was 0.7% (4/561) for the dry and 2.2% (8/368) for the wet season. In poultry, prevalence was 0.2% (2/863) for the dry and 1.4% (24/1,713) for the wet season, while that of swine was 0.0% (0/159) and 2.0% (7/352) in the two seasons, respectively. Of the 45 RT-PCR positive samples, 13 (28.9%) of them were H5 but none was H7. The 19 swine sera positive for influenza antibodies by ELISA were positive for H1 antibodies by HAI assay, but the subtype(s) of ELISA positive poultry sera could not be determined. Antibodies in the poultry sera could have been those against subtypes not included in the HAI test panel. Conclusions The study has demonstrated occurrence of influenza A viruses in animals in Uganda. The results suggest that increase in volumes of migratory waterfowl in the country could be associated with increased prevalence of these viruses in free-living waterfowl and poultry. PMID:24576325

  17. Inhibition of influenza virus infection and hemagglutinin cleavage by the protease inhibitor HAI-2

    SciTech Connect

    Hamilton, Brian S.; Chung, Changik; Cyphers, Soreen Y.; Rinaldi, Vera D.; Marcano, Valerie C.; Whittaker, Gary R.

    2014-07-25

    Highlights: • Biochemical and cell biological analysis of HAI-2 as an inhibitor of influenza HA cleavage activation. • Biochemical and cell biological analysis of HAI-2 as an inhibitor of influenza virus infection. • Comparative analysis of HAI-2 for vesicular stomatitis virus and human parainfluenza virus type-1. • Analysis of the activity of HAI-2 in a mouse model of influenza. - Abstract: Influenza virus remains a significant concern to public health, with the continued potential for a high fatality pandemic. Vaccination and antiviral therapeutics are effective measures to circumvent influenza virus infection, however, multiple strains have emerged that are resistant to the antiviral therapeutics currently on the market. With this considered, investigation of alternative antiviral therapeutics is being conducted. One such approach is to inhibit cleavage activation of the influenza virus hemagglutinin (HA), which is an essential step in the viral replication cycle that permits viral-endosome fusion. Therefore, targeting trypsin-like, host proteases responsible for HA cleavage in vivo may prove to be an effective therapeutic. Hepatocyte growth factor activator inhibitor 2 (HAI-2) is naturally expressed in the respiratory tract and is a potent inhibitor of trypsin-like serine proteases, some of which have been determined to cleave HA. In this study, we demonstrate that HAI-2 is an effective inhibitor of cleavage of HA from the human-adapted H1 and H3 subtypes. HAI-2 inhibited influenza virus H1N1 infection in cell culture, and HAI-2 administration showed protection in a mouse model of influenza. HAI-2 has the potential to be an effective, alternative antiviral therapeutic for influenza.

  18. Nasal commensal Staphylococcus epidermidis counteracts influenza virus

    PubMed Central

    Chen, Hui-Wen; Liu, Pei-Feng; Liu, Yu-Tsueng; Kuo, Sherwin; Zhang, Xing-Quan; Schooley, Robert T.; Rohde, Holger; Gallo, Richard L.; Huang, Chun-Ming

    2016-01-01

    Several microbes, including Staphylococcus epidermidis (S. epidermidis), a Gram-positive bacterium, live inside the human nasal cavity as commensals. The role of these nasal commensals in host innate immunity is largely unknown, although bacterial interference in the nasal microbiome may promote ecological competition between commensal bacteria and pathogenic species. We demonstrate here that S. epidermidis culture supernatants significantly suppressed the infectivity of various influenza viruses. Using high-performance liquid chromatography together with mass spectrometry, we identified a giant extracellular matrix-binding protein (Embp) as the major component involved in the anti-influenza effect of S. epidermidis. This anti-influenza activity was abrogated when Embp was mutated, confirming that Embp is essential for S. epidermidis activity against viral infection. We also showed that both S. epidermidis bacterial particles and Embp can directly bind to influenza virus. Furthermore, the injection of a recombinant Embp fragment containing a fibronectin-binding domain into embryonated eggs increased the survival rate of virus-infected chicken embryos. For an in vivo challenge study, prior Embp intranasal inoculation in chickens suppressed the viral titres and induced the expression of antiviral cytokines in the nasal tissues. These results suggest that S. epidermidis in the nasal cavity may serve as a defence mechanism against influenza virus infection. PMID:27306590

  19. Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae

    SciTech Connect

    Smith, Amber M.; Adler, Frederick R.; Ribeiro, Ruy M.; Gutenkunst, Ryan N.; McAuley, Julie L.; McCullers, Jonathan A.; Perelson, Alan S.

    2013-03-21

    Secondary bacterial infections are a leading cause of illness and death during epidemic and pandemic influenza. Experimental studies suggest a lethal synergism between influenza and certain bacteria, particularly Streptococcus pneumoniae, but the precise processes involved are unclear. In this paper, to address the mechanisms and determine the influences of pathogen dose and strain on disease, we infected groups of mice with either the H1N1 subtype influenza A virus A/Puerto Rico/8/34 (PR8) or a version expressing the 1918 PB1-F2 protein (PR8-PB1-F2(1918)), followed seven days later with one of two S. pneumoniae strains, type 2 D39 or type 3 A66.1. We determined that, following bacterial infection, viral titers initially rebound and then decline slowly. Bacterial titers rapidly rise to high levels and remain elevated. We used a kinetic model to explore the coupled interactions and study the dominant controlling mechanisms. We hypothesize that viral titers rebound in the presence of bacteria due to enhanced viral release from infected cells, and that bacterial titers increase due to alveolar macrophage impairment. Dynamics are affected by initial bacterial dose but not by the expression of the influenza 1918 PB1-F2 protein. Finally, our model provides a framework to investigate pathogen interaction during coinfections and to uncover dynamical differences based on inoculum size and strain.

  20. Kinetics of Coinfection with Influenza A Virus and Streptococcus pneumoniae

    DOE PAGESBeta

    Smith, Amber M.; Adler, Frederick R.; Ribeiro, Ruy M.; Gutenkunst, Ryan N.; McAuley, Julie L.; McCullers, Jonathan A.; Perelson, Alan S.

    2013-03-21

    Secondary bacterial infections are a leading cause of illness and death during epidemic and pandemic influenza. Experimental studies suggest a lethal synergism between influenza and certain bacteria, particularly Streptococcus pneumoniae, but the precise processes involved are unclear. In this paper, to address the mechanisms and determine the influences of pathogen dose and strain on disease, we infected groups of mice with either the H1N1 subtype influenza A virus A/Puerto Rico/8/34 (PR8) or a version expressing the 1918 PB1-F2 protein (PR8-PB1-F2(1918)), followed seven days later with one of two S. pneumoniae strains, type 2 D39 or type 3 A66.1. We determinedmore » that, following bacterial infection, viral titers initially rebound and then decline slowly. Bacterial titers rapidly rise to high levels and remain elevated. We used a kinetic model to explore the coupled interactions and study the dominant controlling mechanisms. We hypothesize that viral titers rebound in the presence of bacteria due to enhanced viral release from infected cells, and that bacterial titers increase due to alveolar macrophage impairment. Dynamics are affected by initial bacterial dose but not by the expression of the influenza 1918 PB1-F2 protein. Finally, our model provides a framework to investigate pathogen interaction during coinfections and to uncover dynamical differences based on inoculum size and strain.« less

  1. Isolation of influenza A viruses from migratory waterfowls in San-in District, Western Japan, in the winter of 1982-1983.

    PubMed

    Otsuki, K; Takemoto, O; Fujimoto, R; Yamazaki, K; Kubota, N; Hosaki, H; Kawaoka, Y; Tsubokura, M

    1987-09-01

    From November 1982 to March 1983, winter migratory waterfowls of some species staying in San-in District, Western Japan, were surveyed for influenza virus at five stations. A total of eight influenza A viruses were isolated from 354 faeces samples of whistling swans; in contrast, no virus was isolated from any sample of 261 black-tailed gulls, of 113 pintails and of 10 mallards. Five of eight isolates belonged to human pandemic subtype H2N2, two isolates belonged to fowl plague subtype H7N7, and the remaining one to subtype H4N6. PMID:2891283

  2. Cross Protection against Influenza A Virus by Yeast-Expressed Heterologous Tandem Repeat M2 Extracellular Proteins.

    PubMed

    Lee, Yu-Na; Kim, Min-Chul; Lee, Young-Tae; Hwang, Hye Suk; Lee, Jongsang; Kim, Cheol; Kang, Sang-Moo

    2015-01-01

    The influenza M2 ectodomain (M2e) is well conserved across human influenza A subtypes, but there are few residue changes among avian and swine origin influenza A viruses. We expressed a tandem repeat construct of heterologous M2e sequences (M2e5x) derived from human, swine, and avian origin influenza A viruses using the yeast expression system. Intramuscular immunization of mice with AS04-adjuvanted M2e5x protein vaccines was effective in inducing M2e-specific antibodies reactive to M2e peptide and native M2 proteins on the infected cells with human, swine, or avian influenza virus, mucosal and systemic memory cellular immune responses, and cross-protection against H3N2 virus. Importantly, M2e5x immune sera were found to confer protection against different subtypes of H1N1 and H5N1 influenza A viruses in naïve mice. Also, M2e5x-immune complexes of virus-infected cells stimulated macrophages to secrete cytokines via Fc receptors, indicating a possible mechanism of protection. The present study provides evidence that M2e5x proteins produced in yeast cells could be developed as a potential universal influenza vaccine. PMID:26366729

  3. Cross Protection against Influenza A Virus by Yeast-Expressed Heterologous Tandem Repeat M2 Extracellular Proteins

    PubMed Central

    Lee, Yu-Na; Kim, Min-Chul; Lee, Young-Tae; Hwang, Hye Suk; Lee, Jongsang; Kim, Cheol; Kang, Sang-Moo

    2015-01-01

    The influenza M2 ectodomain (M2e) is well conserved across human influenza A subtypes, but there are few residue changes among avian and swine origin influenza A viruses. We expressed a tandem repeat construct of heterologous M2e sequences (M2e5x) derived from human, swine, and avian origin influenza A viruses using the yeast expression system. Intramuscular immunization of mice with AS04-adjuvanted M2e5x protein vaccines was effective in inducing M2e-specific antibodies reactive to M2e peptide and native M2 proteins on the infected cells with human, swine, or avian influenza virus, mucosal and systemic memory cellular immune responses, and cross-protection against H3N2 virus. Importantly, M2e5x immune sera were found to confer protection against different subtypes of H1N1 and H5N1 influenza A viruses in naïve mice. Also, M2e5x-immune complexes of virus-infected cells stimulated macrophages to secrete cytokines via Fc receptors, indicating a possible mechanism of protection. The present study provides evidence that M2e5x proteins produced in yeast cells could be developed as a potential universal influenza vaccine. PMID:26366729

  4. Circulation of influenza viruses and paramyxoviruses in waterfowl originating from two different areas of North America

    PubMed Central

    Hinshaw, V. S.; Wood, J. M.; Webster, R. G.; Deibel, R.; Turner, B.

    1985-01-01

    Migratory waterfowl and shore birds harbour a wide range of influenza viruses, some of which have been implicated in influenza outbreaks in mammals and domestic birds. In the present study, a comparison was made of two marshalling areas for different migratory flyways of waterfowl in North America over a 6-8-year period. Virtually all known influenza subtypes were isolated and the predominant subtype changed from year to year. A marked difference between the two locations was that the predominant subtypes circulating were never the same, even though in both areas, most virus isolations were made from the same duck species (mallard duck). Isolations of paramyxovirus were characterized mainly as avian PMV-1. Viruses isolated from ducks included those antigenically related to viruses causing disease in birds and mammals, although the viruses did not necessarily appear in ducks immediately before they appeared in other species. For example, H5N2 isolates antigenically related to the virus causing severe disease outbreaks in chickens in the USA in 1983, were detected in ducks from both areas at different times (1976, 1980 and 1982). These studies indicate that ducks in different areas represent a continual source of orthomyxoviruses and paramyxoviruses of potential disease significance to other species. PMID:3878741

  5. Molecular Characteristics of H6N6 Influenza Virus Isolated from Pigeons in Guangxi, Southern China

    PubMed Central

    Li, Meng; Xie, Zhiqin; Luo, Sisi; Xie, Liji; Huang, Li; Deng, Xianwen; Huang, Jiaoling; Zhang, Yanfang; Zeng, Tingting; Wang, Sheng

    2015-01-01

    Here, we report the complete genome sequence of an H6N6 avian influenza virus (AIV) isolated from a pigeon in Guangxi, southern China, in 2014. The eight RNA segment genes shared a high nucleotide identity (97 to 99%) with H6N6 subtypes of AIV isolated from ducks in the regions around Guangxi Province. The finding of this study will help us understand the ecology and molecular characteristics of H6 avian influenza virus in wild birds in southern China. PMID:26634763

  6. Ambient Influenza and Avian Influenza Virus during Dust Storm Days and Background Days

    PubMed Central

    Chen, Pei-Shih; Tsai, Feng Ta; Lin, Chien Kun; Yang, Chun-Yuh; Chan, Chang-Chuan; Young, Chea-Yuan; Lee, Chien-Hung

    2010-01-01

    Background The spread of influenza and highly pathogenic avian influenza (H5N1) presents a significant threat to human health. Avian influenza outbreaks in downwind areas of Asian dust storms (ADS) suggest that viruses might be transported by dust storms. Objectives We developed a technique to measure ambient influenza and avian influenza viruses. We then used this technique to measure concentrations of these viruses on ADS days and background days, and to assess the relationships between ambient influenza and avian influenza viruses, and air pollutants. Methods A high-volume air sampler was used in parallel with a filter cassette to evaluate spiked samples and unspiked samples. Then, air samples were monitored during ADS seasons using a filter cassette coupled with a real-time quantitative polymerase chain reaction (qPCR) assay. Air samples were monitored during ADS season (1 January to 31 May 2006). Results We successfully quantified ambient influenza virus using the filtration/real-time qPCR method during ADS days and background days. To our knowledge, this is the first report describing the concentration of influenza virus in ambient air. In both the spiked and unspiked samples, the concentration of influenza virus sampled using the filter cassette was higher than that using the high-volume sampler. The concentration of ambient influenza A virus was significantly higher during the ADS days than during the background days. Conclusions Our data imply the possibility of long-range transport of influenza virus. PMID:20435545

  7. Highly Pathogenic Avian Influenza Virus Infection of Mallards with Homo- and Heterosubtypic Immunity Induced by Low Pathogenic Avian Influenza Viruses

    PubMed Central

    Fereidouni, Sasan R.; Starick, Elke; Beer, Martin; Wilking, Hendrik; Kalthoff, Donata; Grund, Christian; Häuslaigner, Rafaela; Breithaupt, Angele; Lange, Elke; Harder, Timm C.

    2009-01-01

    The potential role of wild birds as carriers of highly pathogenic avian influenza virus (HPAIV) subtype H5N1 is still a matter of debate. Consecutive or simultaneous infections with different subtypes of influenza viruses of low pathogenicity (LPAIV) are very common in wild duck populations. To better understand the epidemiology and pathogenesis of HPAIV H5N1 infections in natural ecosystems, we investigated the influence of prior infection of mallards with homo- (H5N2) and heterosubtypic (H4N6) LPAIV on exposure to HPAIV H5N1. In mallards with homosubtypic immunity induced by LPAIV infection, clinical disease was absent and shedding of HPAIV from respiratory and intestinal tracts was grossly reduced compared to the heterosubtypic and control groups (mean GEC/100 µl at 3 dpi: 3.0×102 vs. 2.3×104 vs. 8.7×104; p<0.05). Heterosubtypic immunity induced by an H4N6 infection mediated a similar but less pronounced effect. We conclude that the epidemiology of HPAIV H5N1 in mallards and probably other aquatic wild bird species is massively influenced by interfering immunity induced by prior homo- and heterosubtypic LPAIV infections. PMID:19693268

  8. The NS1 gene from bat-derived influenza-like virus H17N10 can be rescued in influenza A PR8 backbone.

    PubMed

    Zhao, Xuejin; Tefsen, Boris; Li, Yan; Qi, Jianxun; Lu, Guangwen; Shi, Yi; Yan, Jinghua; Xiao, Haixia; Gao, George F

    2016-08-01

    Influenza A viruses have the potential to cause pandemics due to the introduction of novel subtypes against which human hosts have little or no preexisting immunity. Such viruses may result from reassortment between human and animal influenza viruses. Recently, new influenza-like viruses were identified in bats, raising the concern for a new reservoir of potentially harmful influenza viruses that could form reassortants with categorized human influenza A viruses. However, until now, it has not been possible to generate a recombinant reassortant virus containing a single functional gene or domain from H17N10 that could propagate. Here, we demonstrate that a recombinant A/Puerto Rico/8/1934 (H1N1) virus with NS1 gene from H17N10 influenza-like virus can be successfully rescued. We used luciferase reporter assays and quantitative reverse transcriptase PCR to show that the NS1 protein from H17N10 inhibited Sendai-virus (SeV)-induced activation of IFN-β expression with an efficiency similar to NS1 from an H5N1 strain. Moreover, the crystal structure of the NS1 (H17N10) RNA-binding domain is also similar to that of other NS1s. These results demonstrate that H17N10 influenza-like virus indeed contains functional genes that are compatible with categorized influenza A viruses. Although the chance of this particular event occurring in nature seems negligible, further research is needed to address the possibility of the natural formation of reassortants. PMID:27217257

  9. Influenza viruses in birds: rapid identification by counterimmunoelectrophoresis.

    PubMed Central

    Lecomte, J; Berthiaume, L; Boudreault, A

    1979-01-01

    Counterimmunoelectrophoresis with an antiserum raised in rabbits against the M protein of the avian N virus proved to be particularly useful for large-scale identification of influenza A virus isolates. Of a total of 231 hemagglutinating agents isolated from 1,656 rectal swabs collected from shore and open-country birds, 158 could be identified as influenza A viruses by counterimmunoelectrophoresis, and 75 were serologically related to Newcastle disease virus by hemagglutination inhibition with an antiserum to Newcastle disease virus. Two isolates contained a mixture of influenza A virus and Newcastle disease virus; although the Newcastle disease virus virus particles outnumbered the influenza A virus particles in a ratio of 1,000:1, as seen by electron microscopy, the latter could be readily detected by counterimmunoelectrophoresis. This type of assay appears to be of potential use for epidemiological surveillance of influenza virus isolated from humans and animals. It combines specificity, sensitivity, and simplicity. Images PMID:85632

  10. Avian Influenza Virus (H5N1): a Threat to Human Health

    PubMed Central

    Peiris, J. S. Malik; de Jong, Menno D.; Guan, Yi

    2007-01-01

    Pandemic influenza virus has its origins in avian influenza viruses. The highly pathogenic avian influenza virus subtype H5N1 is already panzootic in poultry, with attendant economic consequences. It continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. Therefore, H5N1 virus has rightly received attention as a potential pandemic threat. However, it is noted that the pandemics of 1957 and 1968 did not arise from highly pathogenic influenza viruses, and the next pandemic may well arise from a low-pathogenicity virus. The rationale for particular concern about an H5N1 pandemic is not its inevitability but its potential severity. An H5N1 pandemic is an event of low probability but one of high human health impact and poses a predicament for public health. Here, we review the ecology and evolution of highly pathogenic avian influenza H5N1 viruses, assess the pandemic risk, and address aspects of human H5N1 disease in relation to its epidemiology, clinical presentation, pathogenesis, diagnosis, and management. PMID:17428885

  11. Avian Influenza A(H5N1) Virus in Egypt.

    PubMed

    Kayali, Ghazi; Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S; Maatouq, Asmaa M; Cai, Zhipeng; McKenzie, Pamela P; Webby, Richard J; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A

    2016-03-01

    In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt. PMID:26886164

  12. Avian Influenza A(H5N1) Virus in Egypt

    PubMed Central

    Kandeil, Ahmed; El-Shesheny, Rabeh; Kayed, Ahmed S.; Maatouq, Asmaa M.; Cai, Zhipeng; McKenzie, Pamela P.; Webby, Richard J.; El Refaey, Samir; Kandeel, Amr; Ali, Mohamed A.

    2016-01-01

    In Egypt, avian influenza A subtype H5N1 and H9N2 viruses are enzootic in poultry. The control plan devised by veterinary authorities in Egypt to prevent infections in poultry focused mainly on vaccination and ultimately failed. Recently, widespread H5N1 infections in poultry and a substantial increase in the number of human cases of H5N1 infection were observed. We summarize surveillance data from 2009 through 2014 and show that avian influenza viruses are established in poultry in Egypt and are continuously evolving genetically and antigenically. We also discuss the epidemiology of human infection with avian influenza in Egypt and describe how the true burden of disease is underestimated. We discuss the failures of relying on vaccinating poultry as the sole intervention tool. We conclude by highlighting the key components that need to be included in a new strategy to control avian influenza infections in poultry and humans in Egypt. PMID:26886164

  13. Evolution of canine and equine influenza (H3N8) viruses co-circulating between 2005 and 2008

    SciTech Connect

    Rivailler, Pierre; Perry, Ijeoma A.; Jang Yunho; Davis, C. Todd; Chen Limei; Dubovi, Edward J.; Donis, Ruben O.

    2010-12-05

    Influenza virus, subtype H3N8, was transmitted from horses to greyhound dogs in 2004 and subsequently spread to pet dog populations. The co-circulation of H3N8 viruses in dogs and horses makes bi-directional virus transmission between these animal species possible. To understand the dynamics of viral transmission, we performed virologic surveillance in dogs and horses between 2005 and 2008 in the United States. The genomes of influenza A H3N8 viruses isolated from 36 dogs and horses were sequenced to determine their origin and evolution. Phylogenetic analyses revealed that H3N8 influenza viruses from horses and dogs were monophyletic and distinct. There was no evidence of canine influenza virus infection in horses with respiratory disease or new introductions of equine influenza viruses into dogs in the United States. Analysis of a limited number of equine influenza viruses suggested substantial separation in the transmission of viruses causing clinically apparent influenza in dogs and horses.

  14. A genetically adjuvanted influenza B virus vector increases immunogenicity and protective efficacy in mice.

    PubMed

    Kittel, Christian; Wressnigg, Nina; Shurygina, Anna Polina; Wolschek, Markus; Stukova, Marina; Romanovskaya-Romanko, Ekatherina; Romanova, Julia; Kiselev, Oleg; Muster, Thomas; Egorov, Andrej

    2015-10-01

    The existence of multiple antigenically distinct types and subtypes of influenza viruses allows the construction of a multivalent vector system for the mucosal delivery of foreign sequences. Influenza A viruses have been exploited successfully for the expression of extraneous antigens as well as immunostimulatory molecules. In this study, we describe the development of an influenza B virus vector whose functional part of the interferon antagonist NS1 was replaced by human interleukin 2 (IL2) as a genetic adjuvant. We demonstrate that IL2 expressed by this viral vector displays immune adjuvant activity in immunized mice. Animals vaccinated with the IL2 viral vector showed an increased hemagglutination inhibition antibody response and higher protective efficacy after challenge with a wild-type influenza B virus when compared to mice vaccinated with a control virus. Our results demonstrate that it is feasible to construct influenza B vaccine strains expressing immune-potentiating foreign sequences from the NS genomic segment. Based on these data, it is now hypothetically possible to create a trivalent (or quadrivalent) live attenuated influenza vaccine in which each component expresses a selected genetic adjuvant with tailored expression levels. PMID:26215439

  15. THE MOLECULAR BIOLOGY OF AVIAN INFLUENZA VIRUS IN SHORT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza virus (AIV) is an important pathogen of poultry as it can cause severe economic losses through disease, including respiratory signs and mortality, and effects on trade. Avian influenza virus is classified as type A influenza, which is a member of the orthomyxoviridae family. Charact...

  16. Swine as a model for influenza A virus infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A viruses (IAV) infect a variety of hosts, including humans, swine, and various avian species. The annual influenza disease burden in the human population remains significant even with current vaccine usage and much about the pathogenesis and transmission of influenza viruses in human rema...

  17. KINETIC PROFILE OF INFLUENZA VIRUS INFECTION IN THREE RAT STRAINS

    EPA Science Inventory

    Abstract

    Influenza infection is a respiratory disease of viral origin that can cause major epidemics in man. The influenza virus infects and damages epithelial cells of the respiratory tract and causes pneumonia. Lung lesions of mice infected with influenza virus resembl...

  18. Differential Recognition of Influenza A Viruses by M158–66 Epitope-Specific CD8+ T Cells Is Determined by Extraepitopic Amino Acid Residues

    PubMed Central

    van de Sandt, Carolien E.; Kreijtz, Joost H. C. M.; Geelhoed-Mieras, Martina M.; Nieuwkoop, Nella J.; Spronken, Monique I.; van de Vijver, David A. M. C.; Fouchier, Ron A. M.; Osterhaus, Albert D. M. E.

    2015-01-01

    ABSTRACT Natural influenza A virus infections elicit both virus-specific antibody and CD4+ and CD8+ T cell responses. Influenza A virus-specific CD8+ cytotoxic T lymphocytes (CTLs) contribute to clearance of influenza virus infections. Viral CTL epitopes can display variation, allowing influenza A viruses to evade recognition by epitope-specific CTLs. Due to functional constraints, some epitopes, like the immunodominant HLA-A*0201-restricted matrix protein 1 (M158–66) epitope, are highly conserved between influenza A viruses regardless of their subtype or host species of origin. We hypothesized that human influenza A viruses evade recognition of this epitope by impairing antigen processing and presentation by extraepitopic amino acid substitutions. Activation of specific T cells was used as an indication of antigen presentation. Here, we show that the M158–66 epitope in the M1 protein derived from human influenza A virus was poorly recognized compared to the M1 protein derived from avian influenza A virus. Furthermore, we demonstrate that naturally occurring variations at extraepitopic amino acid residues affect CD8+ T cell recognition of the M158–66 epitope. These data indicate that human influenza A viruses can impair recognition by M158–66-specific CTLs while retaining the conserved amino acid sequence of the epitope, which may represent a yet-unknown immune evasion strategy for influenza A viruses. This difference in recognition may have implications for the viral replication kinetics in HLA-A*0201 individuals and spread of influenza A viruses in the human population. The findings may aid the rational design of universal influenza vaccines that aim at the induction of cross-reactive virus-specific CTL responses. IMPORTANCE Influenza viruses are an important cause of acute respiratory tract infections. Natural influenza A virus infections elicit both humoral and cellular immunity. CD8+ cytotoxic T lymphocytes (CTLs) are directed predominantly against

  19. Broadly protective adenovirus-based multivalent vaccines against highly pathogenic avian influenza viruses for pandemic preparedness.

    PubMed

    Vemula, Sai V; Ahi, Yadvinder S; Swaim, Anne-Marie; Katz, Jacqueline M; Donis, Ruben; Sambhara, Suryaprakash; Mittal, Suresh K

    2013-01-01

    Recurrent outbreaks of H5, H7 and H9 avian influenza viruses in domestic poultry accompanied by their occasional transmission to humans have highlighted the public health threat posed by these viruses. Newer vaccine approaches for pandemic preparedness against these viruses are needed, given the limitations of vaccines currently approved for H5N1 viruses in terms of their production timelines and the ability to induce protective immune responses in the absence of adjuvants. In this study, we evaluated the feasibility of an adenovirus (AdV)-based multivalent vaccine approach for pandemic preparedness against H5, H7 and H9 avian influenza viruses in a mouse model. Replication-defective AdV vectors expressing hemagglutinin (HA) from different subtypes and nucleoprotein (NP) from one subtype induced high levels of humoral and cellular immune responses and conferred protection against virus replication following challenge with H5, H7 and H9 avian influenza virus subtypes. Inclusion of HA from the 2009 H1N1 pandemic virus in the vaccine formulation further broadened the vaccine coverage. Significantly high levels of HA stalk-specific antibodies were observed following immunization with the multivalent vaccine. Inclusion of NP into the multivalent HA vaccine formulation resulted in the induction of CD8 T cell responses. These results suggest that a multivalent vaccine strategy may provide reasonable protection in the event of a pandemic caused by H5, H7, or H9 avian influenza virus before a strain-matched vaccine can be produced. PMID:23638099

  20. A High Diversity of Eurasian Lineage Low Pathogenicity Avian Influenza A Viruses Circulate among Wild Birds Sampled in Egypt

    PubMed Central

    Gerloff, Nancy A.; Jones, Joyce; Simpson, Natosha; Balish, Amanda; ElBadry, Maha Adel; Baghat, Verina; Rusev, Ivan; de Mattos, Cecilia C.; de Mattos, Carlos A.; Zonkle, Luay Elsayed Ahmed; Kis, Zoltan; Davis, C. Todd; Yingst, Sam; Cornelius, Claire; Soliman, Atef; Mohareb, Emad; Klimov, Alexander; Donis, Ruben O.

    2013-01-01

    Surveillance for influenza A viruses in wild birds has increased substantially as part of efforts to control the global movement of highly pathogenic avian influenza A (H5N1) virus. Studies conducted in Egypt from 2003 to 2007 to monitor birds for H5N1 identified multiple subtypes of low pathogenicity avian influenza A viruses isolated primarily from migratory waterfowl collected in the Nile Delta. Phylogenetic analysis of 28 viral genomes was performed to estimate their nearest ancestors and identify possible reassortants. Migratory flyway patterns were included in the analysis to assess gene flow between overlapping flyways. Overall, the viruses were most closely related to Eurasian, African and/or Central Asian lineage low pathogenicity viruses and belonged to 15 different subtypes. A subset of the internal genes seemed to originate from specific flyways (Black Sea-Mediterranean, East African-West Asian). The remaining genes were derived from a mixture of viruses broadly distributed across as many as 4 different flyways suggesting the importance of the Nile Delta for virus dispersal. Molecular clock date estimates suggested that the time to the nearest common ancestor of all viruses analyzed ranged from 5 to 10 years, indicating frequent genetic exchange with viruses sampled elsewhere. The intersection of multiple migratory bird flyways and the resulting diversity of influenza virus gene lineages in the Nile Delta create conditions favoring reassortment, as evident from the gene constellations identified by this study. In conclusion, we present for the first time a comprehensive phylogenetic analysis of full genome sequences from low pathogenic avian influenza viruses circulating in Egypt, underscoring the significance of the region for viral reassortment and the potential emergence of novel avian influenza A viruses, as well as representing a highly diverse influenza A virus gene pool that merits continued monitoring. PMID:23874653

  1. Interaction of nanodiamonds materials with influenza viruses

    NASA Astrophysics Data System (ADS)

    Ivanova, V. T.; Ivanova, M. V.; Spitsyn, B. V.; Garina, K. O.; Trushakova, S. V.; Manykin, A. A.; Korzhenevsky, A. P.; Burseva, E. I.

    2012-02-01

    The perspectives of the application of modern materials contained nanodiamonds (ND) are considered in this study. The interaction between detonation paniculate ND, soot and influenza A and B viruses, fragments of cDNA were analyzed at the normal conditions. It was shown that these sorbents can interact with the following viruses: reference epidemic strains of influenza A(H1N1), A(H1N1)v, A(H3N2) and B viruses circulated in the word in 2000-2010. The allantoises, concentrated viruses, cDNA can be absorbed by ND sorbents and getting removed from water solutions within 20 min. ND sorbents can be used for the preparation of antivirus filters for water solution and for future diagnostic systems in virology.

  2. Protective effects of phillyrin against influenza A virus in vivo.

    PubMed

    Qu, Xin-Yan; Li, Qing-Jun; Zhang, Hui-Min; Zhang, Xiao-Juan; Shi, Peng-Hui; Zhang, Xiu-Juan; Yang, Jing; Zhou, Zhe; Wang, Sheng-Qi

    2016-07-01

    Influenza A virus infection represents a great threat to public health. However, owing to side effects and the emergence of resistant virus strains, the use of currently available anti-influenza drugs may be limited. In order to identify novel anti-influenza drugs, we investigated the antiviral effects of phillyrin against influenza A virus infection in vivo. The mean survival time, lung index, viral titers, influenza hemagglutinin (HA) protein and serum cytokines levels, and histopathological changes in lung tissue were examined. Administration of phillyrin at a dose of 20 mg/kg/day for 3 days significantly prolonged the mean survival time, reduced the lung index, decreased the virus titers and interleukin-6 levels, reduced the expression of HA, and attenuated lung tissue damage in mice infected with influenza A virus. Taken together, these data showed that phillyrin had potential protective effects against infection caused by influenza A virus. PMID:27323762

  3. Human Immunodeficiency Virus Type 1 Subtypes Prevalence in Central China

    PubMed Central

    Wang, Zhe; Li, Wen-jie

    2009-01-01

    Purpose To study the epidemic characteristics, transmission sources and routes of various subtypes of human immunodeficiency virus type 1 (HIV-1) and sequence variations in Henan, central China. To provide theoretical foundation for Acquired Immune Deficiency Syndrome (AIDS) prevention strategy in this region where the primary HIV transmission route was through former paid blood donation. Materials and Methods HIV-1 gene env and gag were amplified by nested polymerase chain reaction (PCR) from uncultured peripheral blood mononuclear cells (PBMCs) obtained from 1,287 HIV-1 confirmed samples in Henan. Results Among 1,287 samples, 5 HIV-1 strains were found including subtypes B' (95.9%), C (0.47%) and recombinant subtypes CRF 07_BC (1.09%), CRF 08_BC (1.79%) and CRF 01_AE (0.78%). Phylogenetic tree analysis found that 1,234 Henan subtype B' were closely related to those commonly found in Thailand, and were distantly related to other international subtypes. The dominant strain in former blood plasma donors (FPDs) was subtype B', and the dominant strains in sexual transmission were subtype B' and BC. Among HIV patients who were most likely infected through routes other than paid blood donation, the percentage of non-B' subtypes was much higher than those of FPD. Conclusion These findings suggest that the prevailing strain of HIV-1 in Henan is subtype B', similar to the B' subtype found in Thailand. In addition, for the first time we found subtypes C and recombinant subtypes CRF07_BC, CRF08_BC and CRF01_AE in this region. Indicating that the subtype feature of HIV-1 became more complicated than before in central China. PMID:19881967

  4. Characterization of a novel H3N2 influenza virus isolated from domestic ducks in China.

    PubMed

    Li, Chong; Yu, Meng; Liu, Litao; Sun, Honglei

    2016-08-01

    Cases of human infection with a novel H7N9 avian influenza virus (AIV) were first reported in March 2013, which caused 115 deaths within a single year. Beyond that, other subtypes of H7 AIV were isolated from poultry in eastern China during the same period, including H7N7 and H7N2 AIV. In the present study, a subtype H3N2 AIV was isolated from ducks from Anhui Province, China. Sequence and phylogenetic analyses revealed that seven gene segments of this virus showed the highest sequence homology with that of the H7 subtype influenza virus, which is presumed to be the reassortants of the H3 and H7 subtypes AIV. The present study also reconfirmed that the reassortment between the H7 subtype and waterfowl-originating AIVs universally occurred in waterfowl. Animal inoculation tests showed that the virus has low pathogenicity in chickens; however, it could be replicated in the lungs of mice. The emergence of this H3N2 isolate emphasizes the importance of enhancing the surveillance of waterfowl-originating AIVs, the identification of novel reassortant strains, and characterization of their biological properties. PMID:27000112

  5. The changing face of swine influenza virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    "Flu" in pigs has been known for 90 years and on the surface it may appear as though little has changed. We still suspect flu when a high percentage of pigs have a sudden onset of barking cough, especially during temperature fluctuations in the fall or spring. However, the influenza viruses responsi...

  6. The influenza fingerprints: NS1 and M1 proteins contribute to specific host cell ultrastructure signatures upon infection by different influenza A viruses

    SciTech Connect

    Terrier, Olivier; Moules, Vincent; Carron, Coralie; Cartet, Gaeelle; Frobert, Emilie; Yver, Matthieu; Traversier, Aurelien; Wolff, Thorsten; Naffakh, Nadia; and others

    2012-10-10

    Influenza A are nuclear replicating viruses which hijack host machineries in order to achieve optimal infection. Numerous functional virus-host interactions have now been characterized, but little information has been gathered concerning their link to the virally induced remodeling of the host cellular architecture. In this study, we infected cells with several human and avian influenza viruses and we have analyzed their ultrastructural modifications by using electron and confocal microscopy. We discovered that infections lead to a major and systematic disruption of nucleoli and the formation of a large number of diverse viral structures showing specificity that depended on the subtype origin and genomic composition of viruses. We identified NS1 and M1 proteins as the main actors in the remodeling of the host ultra-structure and our results suggest that each influenza A virus strain could be associated with a specific cellular fingerprint, possibly correlated to the functional properties of their viral components.

  7. Development of an Immunochromatographic Strip for Rapid Detection of H9 Subtype Avian Influenza Viruses▿

    PubMed Central

    Peng, Fuhu; Wang, Zheng; Zhang, Shuhui; Wu, Renwei; Hu, Sishun; Li, Zili; Wang, Xiliang; Bi, Dingren

    2008-01-01

    An immunochromatographic strip was developed for the detection of the H9 subtype of avian influenza viruses (H9AIVs) in poultry, using two monoclonal antibodies (MAb), 4C4 for H9AIV hemagglutinin (HA) and 4D4 for nucleoprotein. The 4C4 MAb was labeled with colloidal gold as the detection reagent, and the 4D4 MAb was blotted on the test line while a goat anti-mouse antibody was used on the control line of the nitrocellulose membrane. In comparison with the HA and HA inhibition (HI) tests, the strip was specific for the detection of H9AIV, with a sensitivity at 0.25 HA units within 10 min. Storage of the strips at room temperature for 6 months or at 4°C for 12 months did not change their sensitivity and specificity. Evaluation of the strip with experimental tracheal and cloacal swab samples collected from H9N2-infected chickens revealed that the strip detected the H9N2 viruses on day 3 postinoculation, earlier than the appearance of clinical symptoms. Application of the strip for the analysis of 157 tracheal or cloacal samples from potentially infected chickens on five poultry farms showed that four farms had chickens that were infected with H9AIV. Further characterization of 10 positive and 30 negative randomly selected samples showed that no single sample was false positive or negative, as determined by the standard virus isolation and HI assays. Therefore, the immunochromatographic strip for the detection of H9AIVs has high specificity, sensitivity, and stability. This finding, together with the advantages of rapid detection and easy operation and without the requirement for special skills and equipment, makes the strip suitable for onsite detection and the differentiation of H9AIVs from other viruses in poultry. PMID:18199737

  8. Heterologous SH3-p85β inhibits influenza A virus replication

    PubMed Central

    2010-01-01

    Phosphatidylinositol 3-kinase (PI3K)/Akt signalling pathway can support the replication of influenza A virus through binding of viral NS1 protein to the Src homology 3 (SH3) domain of p85β regulatory subunit of PI3K. Here we investigated the effect of heterologously overexpressed SH3 on the replication of different influenza A virus subtypes/strains, and on the phosphorylation of Akt in the virus-infected cells. We found that heterologous SH3 reduced replication of influenza A viruses at varying degrees in a subtype/strain-dependent manner and SH3 overexpression reduced the induction of the phosphorylation of Akt in the cells infected with PR8(H1N1) and ST364(H3N2), but not with ST1233(H1N1), Ph2246(H9N2), and Qa199(H9N2). Our results suggest that interference with the NS1-p85β interaction by heterologous SH3 can be served as a useful antiviral strategy against influenza A virus infection. PMID:20653952

  9. Development of a cross protective high growth reasssortant H7N7/PR8 virus for clinical evaluation as an inactivated pre-pandemic influenza vaccine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Interspecies transmission of high pathogenicity (HP) H7N7 subtype avian influenza viruses in the Netherlands in 2003 caused zoonotic infections in 89 people, including one fatal case of acute respiratory distress syndrome. Public health preparedness approaches against emerging HP H7N7 influenza vir...

  10. Active Surveillance for Influenza A Virus among Swine, Midwestern United States, 2009–2011

    PubMed Central

    Corzo, Cesar A.; Juleen, Kevin; Stigger-Rosser, Evelyn; Ducatez, Mariette F.; Webby, Richard J.; Lowe, James F.

    2013-01-01

    Veterinary diagnostic laboratories identify and characterize influenza A viruses primarily through passive surveillance. However, additional surveillance programs are needed. To meet this need, an active surveillance program was conducted at pig farms throughout the midwestern United States. From June 2009 through December 2011, nasal swab samples were collected monthly from among 540 groups of growing pigs and tested for influenza A virus by real-time reverse transcription PCR. Of 16,170 samples, 746 were positive for influenza A virus; of these, 18.0% were subtype H1N1, 16.0% H1N2, 7.6% H3N2, and 14.5% (H1N1)pdm09. An influenza (H3N2) and (H1N1)pdm09 virus were identified simultaneously in 8 groups. This active influenza A virus surveillance program provided quality data and increased the understanding of the current situation of circulating viruses in the midwestern US pig population. PMID:23735740

  11. Avian influenza A viruses of southern China and Hong Kong: ecological aspects and implications for man*

    PubMed Central

    Shortridge, K. F.

    1982-01-01

    Continuous surveillance of the influenza viruses isolated from domestic poultry from southern China and Hong Kong over more than 4 years resulted in the isolation of influenza viruses possessing 46 different combinations of haemagglutinin (H) and neuraminidase (N) subtypes. Of these, 43 were obtained from ducks from China. In all cases, infection appeared to be asymptomatic. The antigenic combination found most commonly in the viruses isolated was H4N6, which accounted for approximately one-quarter of the duck isolates, its occurrence being more frequent than expected from a statistical analysis of the observed frequencies of the haemagglutinin and neuraminidase genes among all the isolates. Some combinations of H and N occurred less frequently than expected or not at all. Influenza viruses tended to be isolated more frequently from ducks during the summer months in comparison with paramyxoviruses, which were more commonly encountered in the winter. Possible reasons for the great antigenic diversity of influenza A viruses in the poultry, especially the ducks, in the region are discussed together with the potential significance of these viruses to the emergence of human influenza pandemics. PMID:6979416

  12. Possible Role of Songbirds and Parakeets in Transmission of Influenza A(H7N9) Virus to Humans

    PubMed Central

    Jones, Jeremy C.; Sonnberg, Stephanie; Koçer, Zeynep A.; Shanmuganatham, Karthik; Seiler, Patrick; Shu, Yuelong; Zhu, Huachen; Guan, Yi; Peiris, Malik; Webby, Richard J.

    2014-01-01

    Avian-origin influenza A(H7N9) recently emerged in China, causing severe human disease. Several subtype H7N9 isolates contain influenza genes previously identified in viruses from finch-like birds. Because wild and domestic songbirds interact with humans and poultry, we investigated the susceptibility and transmissibility of subtype H7N9 in these species. Finches, sparrows, and parakeets supported replication of a human subtype H7N9 isolate, shed high titers through the oropharyngeal route, and showed few disease signs. Virus was shed into water troughs, and several contact animals seroconverted, although they shed little virus. Our study demonstrates that a human isolate can replicate in and be shed by such songbirds and parakeets into their environment. This finding has implications for these birds’ potential as intermediate hosts with the ability to facilitate transmission and dissemination of A(H7N9) virus. PMID:24572739

  13. Possible role of songbirds and parakeets in transmission of influenza A(H7N9) virus to humans.

    PubMed

    Jones, Jeremy C; Sonnberg, Stephanie; Koçer, Zeynep A; Shanmuganatham, Karthik; Seiler, Patrick; Shu, Yuelong; Zhu, Huachen; Guan, Yi; Peiris, Malik; Webby, Richard J; Webster, Robert G

    2014-03-01

    Avian-origin influenza A(H7N9) recently emerged in China, causing severe human disease. Several subtype H7N9 isolates contain influenza genes previously identified in viruses from finch-like birds. Because wild and domestic songbirds interact with humans and poultry, we investigated the susceptibility and transmissibility of subtype H7N9 in these species. Finches, sparrows, and parakeets supported replication of a human subtype H7N9 isolate, shed high titers through the oropharyngeal route, and showed few disease signs. Virus was shed into water troughs, and several contact animals seroconverted, although they shed little virus. Our study demonstrates that a human isolate can replicate in and be shed by such songbirds and parakeets into their environment. This finding has implications for these birds' potential as intermediate hosts with the ability to facilitate transmission and dissemination of A(H7N9) virus. PMID:24572739

  14. Antiviral Susceptibility of Avian and Swine Influenza Virus of the N1 Neuraminidase Subtype▿

    PubMed Central

    Stoner, Terri D.; Krauss, Scott; DuBois, Rebecca M.; Negovetich, Nicholas J.; Stallknecht, David E.; Senne, Dennis A.; Gramer, Marie R.; Swafford, Seth; DeLiberto, Tom; Govorkova, Elena A.; Webster, Robert G.

    2010-01-01

    Influenza viruses of the N1 neuraminidase (NA) subtype affecting both animals and humans caused the 2009 pandemic. Anti-influenza virus NA inhibitors are crucial early in a pandemic, when specific influenza vaccines are unavailable. Thus, it is urgent to confirm the antiviral susceptibility of the avian viruses, a potential source of a pandemic virus. We evaluated the NA inhibitor susceptibilities of viruses of the N1 subtype isolated from wild waterbirds, swine, and humans. Most avian viruses were highly or moderately susceptible to oseltamivir (50% inhibitory concentration [IC50], <5.1 to 50 nM). Of 91 avian isolates, 7 (7.7%) had reduced susceptibility (IC50, >50 nM) but were sensitive to the NA inhibitors zanamivir and peramivir. Oseltamivir susceptibility ranged more widely among the waterbird viruses (IC50, 0.5 to 154.43 nM) than among swine and human viruses (IC50, 0.33 to 2.56 nM). Swine viruses were sensitive to oseltamivir, compared to human seasonal H1N1 isolated before 2007 (mean IC50, 1.4 nM). Avian viruses from 2007 to 2008 were sensitive to oseltamivir, in contrast to the emergence of resistant H1N1 in humans. Susceptibility remained high to moderate over time among influenza viruses. Sequence analysis of the outliers did not detect molecular markers of drug-resistance (e.g., H275Y NA mutation [N1 numbering]) but revealed mutations outside the NA active site. In particular, V267I, N307D, and V321I residue changes were found, and structural analyses suggest that these mutations distort hydrophobic pockets and affect residues in the NA active site. We determined that natural oseltamivir resistance among swine and wild waterbirds is rare. Minor naturally occurring variants in NA can affect antiviral susceptibility. PMID:20660186

  15. Prevalence and characterization of influenza viruses in diverse species in Los Llanos, Colombia.

    PubMed

    Karlsson, Erik A; Ciuoderis, Karl; Freiden, Pamela J; Seufzer, Bradley; Jones, Jeremy C; Johnson, Jordan; Parra, Rocio; Gongora, Agustin; Cardenas, Dario; Barajas, Diana; Osorio, Jorge E; Schultz-Cherry, Stacey

    2013-04-01

    While much is known about the prevalence of influenza viruses in North America and Eurasia, their prevalence in birds and mammals in South America is largely unknown. To fill this knowledge gap and provide a baseline for future ecology and epidemiology studies, we conducted 2 years of influenza surveillance in the eastern plains (Los Llanos) region of Colombia. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) identified influenza viruses in wild birds, domestic poultry, swine and horses. Prevalence ranged from 2.6% to 13.4% across species. Swine showed the highest prevalence and were infected primarily with 2009 pandemic H1N1 (pH1N1) viruses genetically related to those in humans. In addition, we isolated H5N2 viruses from two resident species of whistling ducks (genus Dendrocygna) that differed completely from previous South American isolates, instead genetically resembling North American wild bird viruses. Both strains caused low pathogenicity in chickens and mammals. The prevalence and subtype diversity of influenza viruses isolated from diverse species within a small area of Colombia highlights the need for enhanced surveillance throughout South America, including monitoring of the potential transmissibility of low-pathogenic H5N2 viruses from wild birds to domestic poultry and the emergence of reassortant viruses in domestic swine. PMID:26038461

  16. Prevalence and characterization of influenza viruses in diverse species in Los Llanos, Colombia

    PubMed Central

    Karlsson, Erik A; Ciuoderis, Karl; Freiden, Pamela J; Seufzer, Bradley; Jones, Jeremy C; Johnson, Jordan; Parra, Rocio; Gongora, Agustin; Cardenas, Dario; Barajas, Diana; Osorio, Jorge E; Schultz-Cherry, Stacey

    2013-01-01

    While much is known about the prevalence of influenza viruses in North America and Eurasia, their prevalence in birds and mammals in South America is largely unknown. To fill this knowledge gap and provide a baseline for future ecology and epidemiology studies, we conducted 2 years of influenza surveillance in the eastern plains (Los Llanos) region of Colombia. Real-time reverse transcriptase polymerase chain reaction (RT-PCR) identified influenza viruses in wild birds, domestic poultry, swine and horses. Prevalence ranged from 2.6% to 13.4% across species. Swine showed the highest prevalence and were infected primarily with 2009 pandemic H1N1 (pH1N1) viruses genetically related to those in humans. In addition, we isolated H5N2 viruses from two resident species of whistling ducks (genus Dendrocygna) that differed completely from previous South American isolates, instead genetically resembling North American wild bird viruses. Both strains caused low pathogenicity in chickens and mammals. The prevalence and subtype diversity of influenza viruses isolated from diverse species within a small area of Colombia highlights the need for enhanced surveillance throughout South America, including monitoring of the potential transmissibility of low-pathogenic H5N2 viruses from wild birds to domestic poultry and the emergence of reassortant viruses in domestic swine. PMID:26038461

  17. Promoter analysis of influenza virus RNA polymerase.

    PubMed Central

    Parvin, J D; Palese, P; Honda, A; Ishihama, A; Krystal, M

    1989-01-01

    Influenza virus polymerase, which was prepared depleted of viral RNA, was used to copy small RNA templates prepared from plasmid-encoded sequences. Template constructions containing only the 3' end of genomic RNA were shown to be efficiently copied, indicating that the promoter lay solely within the 15-nucleotide 3' terminus. Sequences not specific for the influenza virus termini were not copied, and, surprisingly, RNAs containing termini identical to those from plus-sense cRNA were copied at low levels. The specificity for recognition of the virus sense promoter was further defined by site-specific mutagenesis. It was also found that increased levels of viral protein were required in order to catalyze both the cap endonuclease-primed and primer-free RNA synthesis from these model templates, as well as from genomic-length RNAs. This finding indicates that the reconstituted system has catalytic properties very similar to those of native viral ribonucleoprotein complexes. Images PMID:2585601

  18. Influenza Virus Evolution, Host Adaptation and Pandemic Formation

    PubMed Central

    Taubenberger, Jeffery K.; Kash, John C.

    2010-01-01

    Newly emerging or `re-emerging' viral diseases continue to pose significant global public health threats. Prototypic are influenza viruses that are major causes of human respiratory infections and mortality. Influenza viruses can cause zoonotic infections and adapt to humans leading to sustained transmission and emergence of novel viruses. Mechanisms by which viruses evolve in one host, cause zoonotic infection and adapt to a new host species remain unelucidated. Here we review evolution of influenza A viruses in their reservoir hosts and discuss genetic changes associated with introduction of novel viruses into humans leading to pandemics and the establishment of seasonal viruses. PMID:20542248

  19. ClassyFlu: classification of influenza A viruses with Discriminatively trained profile-HMMs.

    PubMed

    Van der Auwera, Sandra; Bulla, Ingo; Ziller, Mario; Pohlmann, Anne; Harder, Timm; Stanke, Mario

    2014-01-01

    Accurate and rapid characterization of influenza A virus (IAV) hemagglutinin (HA) and neuraminidase (NA) sequences with respect to subtype and clade is at the basis of extended diagnostic services and implicit to molecular epidemiologic studies. ClassyFlu is a new tool and web service for the classification of IAV sequences of the HA and NA gene into subtypes and phylogenetic clades using discriminatively trained profile hidden Markov models (HMMs), one for each subtype or clade. ClassyFlu merely requires as input unaligned, full-length or partial HA or NA DNA sequences. It enables rapid and highly accurate assignment of HA sequences to subtypes H1-H17 but particularly focusses on the finer grained assignment of sequences of highly pathogenic avian influenza viruses of subtype H5N1 according to the cladistics proposed by the H5N1 Evolution Working Group. NA sequences are classified into subtypes N1-N10. ClassyFlu was compared to semiautomatic classification approaches using BLAST and phylogenetics and additionally for H5 sequences to the new "Highly Pathogenic H5N1 Clade Classification Tool" (IRD-CT) proposed by the Influenza Research Database. Our results show that both web tools (ClassyFlu and IRD-CT), although based on different methods, are nearly equivalent in performance and both are more accurate and faster than semiautomatic classification. A retraining of ClassyFlu to altered cladistics as well as an extension of ClassyFlu to other IAV genome segments or fragments thereof is undemanding. This is exemplified by unambiguous assignment to a distinct cluster within subtype H7 of sequences of H7N9 viruses which emerged in China early in 2013 and caused more than 130 human infections. http://bioinf.uni-greifswald.de/ClassyFlu is a free web service. For local execution, the ClassyFlu source code in PERL is freely available. PMID:24404173

  20. Characterization and Sequencing of an H6N6 Avian Influenza Virus Isolated from Sansui Sheldrake Ducks in Guizhou, Southwestern China.

    PubMed

    Duan, Zhiqiang; Chen, Jiaqi; Ji, Xinqin; Xu, Houqiang; Ruan, Yong; Zhao, Jiafu

    2016-01-01

    Here, we report the complete genome sequence of an H6N6 avian influenza virus (AIV) isolated from Sansui Sheldrake ducks in Guizhou Province, China, in 2014. Phylogenetic analysis showed that the H6N6 virus was a reassortant virus derived from three different H6 subtype lineages. The finding of this study will help us understand the epidemiology and the evolutionary characteristics of H6 subtypes of AIV in ducks in southwestern China. PMID:27174267

  1. Characterization and Sequencing of an H6N6 Avian Influenza Virus Isolated from Sansui Sheldrake Ducks in Guizhou, Southwestern China

    PubMed Central

    Chen, Jiaqi; Ji, Xinqin; Xu, Houqiang; Ruan, Yong; Zhao, Jiafu

    2016-01-01

    Here, we report the complete genome sequence of an H6N6 avian influenza virus (AIV) isolated from Sansui Sheldrake ducks in Guizhou Province, China, in 2014. Phylogenetic analysis showed that the H6N6 virus was a reassortant virus derived from three different H6 subtype lineages. The finding of this study will help us understand the epidemiology and the evolutionary characteristics of H6 subtypes of AIV in ducks in southwestern China. PMID:27174267

  2. Type a influenza virus surveillance in free-flying, nonmigratory ducks residing on the eastern shore of Maryland

    USGS Publications Warehouse

    Slemons, R.D.; Hansen, W.R.; Converse, K.A.; Senne, D.A.

    2003-01-01

    Virus surveillance in free-flying, nonmigratory ducks living on the eastern shore of Maryland indicated that influenza A viruses were introduced into the area or that the prevalence of endemic infections increased between July 15 and August 27, 1998. Cloacal swabs collected between May 28 and July 15, 1998, were negative for influenza A virus recovery (0/233), whereas 13.9% (29/209) of swabs collected between August 27 and September 2, 1998, were positive for influenza A virus recovery. Five hemagglutinin subtypes (H2, H3, H6, H9, and H12), six neuraminidase subtypes (N1, N2, N4, N5, N6, and N8), and nine HA-NA combinations were identified among 29 influenza A isolates. Interestingly, 18 of the 29 isolates initially appeared to contain two or more HA and/or NA subtypes. The free-flying, nonmigratory ducks served as excellent sentinels for the early detection of type A influenza viruses in the southern half of the Atlantic Migratory Waterfowl Flyway during the earliest phase of the yearly southern migration.

  3. Type A influenza virus surveillance in free-flying, nonmigratory ducks residing on the eastern shore of Maryland

    USGS Publications Warehouse

    Slemons, R.D.; Hansen, W.R.; Converse, K.A.; Senne, D.A.

    2003-01-01

    Virus surveillance in free-flying, nonmigratory ducks living on the eastern shore of Maryland indicated that influenza A viruses were introduced into the area or that the prevalence of endemic infections increased between July 15 and August 27, 1998. Cloacal swabs collected between May 28 and July 15, 1998, were negative for influenza A virus recovery (0/233), whereas 13.9% (29/209) of swabs collected between August 27 and September 2, 1998, were positive for influenza A virus recovery. Five hemagglutinin subtypes (H2, H3, H6, H9, and H12), six neuraminidase subtypes (N1, N2, N4, N5, N6, and N8), and nine HA-NA combinations were identified among 29 influenza A isolates. Interestingly, 18 of the 29 isolates initially appeared to contain two or more HA and/or NA subtypes. The free-flying, nonmigratory ducks served as excellent sentinels for the early detection of type A influenza viruses in the southern half of the Atlantic Migratory Waterfowl Flyway during the earliest phase of the yearly southern migration.

  4. A Human Monoclonal Antibody with Neutralizing Activity against Highly Divergent Influenza Subtypes

    PubMed Central

    Solforosi, Laura; Moreno, Guisella J.; Gubareva, Larisa V.; Mishin, Vasiliy; Di Pietro, Andrea; Vicenzi, Elisa; Siccardi, Antonio G.; Clementi, Massimo; Burioni, Roberto

    2011-01-01

    The interest in broad-range anti-influenza A monoclonal antibodies (mAbs) has recently been strengthened by the identification of anti-hemagglutinin (HA) mAbs endowed with heterosubtypic neutralizing activity to be used in the design of “universal” prophylactic or therapeutic tools. However, the majority of the single mAbs described to date do not bind and neutralize viral isolates belonging to highly divergent subtypes clustering into the two different HA-based influenza phylogenetic groups: the group 1 including, among others, subtypes H1, H2, H5 and H9 and the group 2 including, among others, H3 subtype. Here, we describe a human mAb, named PN-SIA28, capable of binding and neutralizing all tested isolates belonging to phylogenetic group 1, including H1N1, H2N2, H5N1 and H9N2 subtypes and several isolates belonging to group 2, including H3N2 isolates from the first period of the 1968 pandemic. Therefore, PN-SIA28 is capable of neutralizing isolates belonging to subtypes responsible of all the reported pandemics, as well as other subtypes with pandemic potential. The region recognized by PN-SIA28 has been identified on the stem region of HA and includes residues highly conserved among the different influenza subtypes. A deep characterization of PN-SIA28 features may represent a useful help in the improvement of available anti-influenza therapeutic strategies and can provide new tools for the development of universal vaccinal strategies. PMID:22162996

  5. Swine influenza virus: zoonotic potential and vaccination strategies for the control of avian and swine influenzas.

    PubMed

    Thacker, Eileen; Janke, Bruce

    2008-02-15

    Influenza viruses are able to infect humans, swine, and avian species, and swine have long been considered a potential source of new influenza viruses that can infect humans. Swine have receptors to which both avian and mammalian influenza viruses bind, which increases the potential for viruses to exchange genetic sequences and produce new reassortant viruses in swine. A number of genetically diverse viruses are circulating in swine herds throughout the world and are a major cause of concern to the swine industry. Control of swine influenza is primarily through the vaccination of sows, to protect young pigs through maternally derived antibodies. However, influenza viruses continue to circulate in pigs after the decay of maternal antibodies, providing a continuing source of virus on a herd basis. Measures to control avian influenza in commercial poultry operations are dictated by the virulence of the virus. Detection of a highly pathogenic avian influenza (HPAI) virus results in immediate elimination of the flock. Low-pathogenic avian influenza viruses are controlled through vaccination, which is done primarily in turkey flocks. Maintenance of the current HPAI virus-free status of poultry in the United States is through constant surveillance of poultry flocks. Although current influenza vaccines for poultry and swine are inactivated and adjuvanted, ongoing research into the development of newer vaccines, such as DNA, live-virus, or vectored vaccines, is being done. Control of influenza virus infection in poultry and swine is critical to the reduction of potential cross-species adaptation and spread of influenza viruses, which will minimize the risk of animals being the source of the next pandemic. PMID:18269323

  6. The kinase mTOR modulates the antibody response to provide cross-protective immunity to lethal infection with influenza virus.

    PubMed

    Keating, Rachael; Hertz, Tomer; Wehenkel, Marie; Harris, Tarsha L; Edwards, Benjamin A; McClaren, Jennifer L; Brown, Scott A; Surman, Sherri; Wilson, Zachary S; Bradley, Philip; Hurwitz, Julia; Chi, Hongbo; Doherty, Peter C; Thomas, Paul G; McGargill, Maureen A

    2013-12-01

    Highly pathogenic avian influenza viruses pose a continuing global threat. Current vaccines will not protect against newly evolved pandemic viruses. The creation of 'universal' vaccines has been unsuccessful because the immunological mechanisms that promote heterosubtypic immunity are incompletely defined. We found here that rapamycin, an immunosuppressive drug that inhibits the kinase mTOR, promoted cross-strain protection against lethal infection with influenza virus of various subtypes when administered during immunization with influenza virus subtype H3N2. Rapamycin reduced the formation of germinal centers and inhibited class switching in B cells, which yielded a unique repertoire of antibodies that mediated heterosubtypic protection. Our data established a requirement for the mTORC1 complex in B cell class switching and demonstrated that rapamycin skewed the antibody response away from high-affinity variant epitopes and targeted more conserved elements of hemagglutinin. Our findings have implications for the design of a vaccine against influenza virus. PMID:24141387

  7. Phylogenetic and pathogenic analysis of a novel H6N2 avian influenza virus isolated from a green peafowl in a wildlife park.

    PubMed

    Fan, Zhaobin; Ci, Yanpeng; Ma, Yixin; Liu, Liling; Ma, Jianzhang; Li, D Yanbing; Chen, Hualan

    2014-12-01

    H6 subtype avian influenza virus, which has been circulating among different species, causes considerable concern for both veterinary medicine and public health. We isolated a strain of H6N2 avian influenza virus from healthy green peafowl (Pavo muticus) in Qinghuangdao Wildlife Park in Hebei Province, China, in 2012. A phylogenetic analysis indicated that the isolated H6N2 strain had the same gene constellation as southern China strains, which were predominantly isolated from waterfowl distributed in Shantou, Guangxi, and Hunan in 2001-2010. The isolate showed no and low pathogenicity in chickens and ducks, respectively. However, it replicated efficiently in the lungs and turbinate of infected mice, resulting in thickened alveolar septa and moderate interstitial pneumonia. This finding raises concerns that the H6N2 subtype maybe evolve into a novel endemic avian influenza virus. Therefore, periodical surveillance of avian influenza viruses must be undertaken to monitor the advent of novel viruses. PMID:25619010

  8. Origin of the European avian-like swine influenza viruses.

    PubMed

    Krumbholz, Andi; Lange, Jeannette; Sauerbrei, Andreas; Groth, Marco; Platzer, Matthias; Kanrai, Pumaree; Pleschka, Stephan; Scholtissek, Christoph; Büttner, Mathias; Dürrwald, Ralf; Zell, Roland

    2014-11-01

    The avian-like swine influenza viruses emerged in 1979 in Belgium and Germany. Thereafter, they spread through many European swine-producing countries, replaced the circulating classical swine H1N1 influenza viruses, and became endemic. Serological and subsequent molecular data indicated an avian source, but details remained obscure due to a lack of relevant avian influenza virus sequence data. Here, the origin of the European avian-like swine influenza viruses was analysed using a collection of 16 European swine H1N1 influenza viruses sampled in 1979-1981 in Germany, the Netherlands, Belgium, Italy and France, as well as several contemporaneous avian influenza viruses of various serotypes. The phylogenetic trees suggested a triple reassortant with a unique genotype constellation. Time-resolved maximum clade credibility trees indicated times to the most recent common ancestors of 34-46 years (before 2008) depending on the RNA segment and the method of tree inference. PMID:25073465

  9. Edible bird's nest extract inhibits influenza virus infection.

    PubMed

    Guo, Chao-Tan; Takahashi, Tadanobu; Bukawa, Wakoto; Takahashi, Noriko; Yagi, Hirokazu; Kato, Koichi; Hidari, Kazuya I-P Jwa; Miyamoto, Daisei; Suzuki, Takashi; Suzuki, Yasuo

    2006-07-01

    Edible bird's nest (EBN) is the nest of the swift that is made from its saliva. Although EBN has been widely used for enhancing immunocompetence, its antiviral efficacy has not been studied in detail. We found that EBN extract could strongly inhibit infection with influenza viruses in a host range-independent manner when it was hydrolyzed with Pancreatin F. Western blotting assay showed that the EBN extract bound to influenza virus. Furthermore, EBN extract could neutralize the infection of MDCK cells with influenza viruses and inhibit hemagglutination of influenza viruses to erythrocytes, but it could not inhibit the activity of influenza virus sialidase. Fluorometric HPLC indicated that the major molecular species of sialic acid in EBN is N-acetylneuraminic acid. The results suggest that EBN is a safe and valid natural source for the prevention of influenza viruses. PMID:16581142

  10. Transmission of Influenza B Viruses in the Guinea Pig

    PubMed Central

    Pica, Natalie; Chou, Yi-Ying; Bouvier, Nicole M.

    2012-01-01

    Epidemic influenza is typically caused by infection with viruses of the A and B types and can result in substantial morbidity and mortality during a given season. Here we demonstrate that influenza B viruses can replicate in the upper respiratory tract of the guinea pig and that viruses of the two main lineages can be transmitted with 100% efficiency between inoculated and naïve animals in both contact and noncontact models. Our results also indicate that, like in the case for influenza A virus, transmission of influenza B viruses is enhanced at colder temperatures, providing an explanation for the seasonality of influenza epidemics in temperate climates. We therefore present, for the first time, a small animal model with which to study the underlying mechanisms of influenza B virus transmission. PMID:22301149

  11. EXISTING ANTIVIRALS ARE EFFECTIVE AGAINST INFLUENZA VIRUSES WITH GENES FROM THE 1918 PANDEMIC VIRUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The 1918 influenza pandemic caused more than 20 million deaths worldwide. Under biosafety level 3Ag containment, a recombinant influenza virus bearing the 1918 influenza virus hemagglutinin (HA) and neuraminidase (NA) was generated. This virus is highly virulent in mice, pointing to the 1918 HA and...

  12. Pathogenesis and pathobiology of avian influenza virus infection in birds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian Influenza (AI) viruses vary in their ability to produce infection, disease and death in different bird species. Based on the pathobiological features in chickens, AI viruses are categorized as, low (LP) and high pathogenicity (HP). Typically, LPAI (low pathogenicity avian influenza) viruses ...

  13. Global migration of influenza A viruses in swine

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The emergence of the 2009 A/H1N1 pandemic virus underscores the importance of understanding how influenza A viruses evolve in swine on a global scale. To reveal the frequency, patterns and drivers of the spread of swine influenza virus globally, we conducted the largest phylogenetic analysis of swin...

  14. Novel routes of transmission of influenza viruses in poultry species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In order to develop better control measures against influenza it’s necessary to understand how the virus transmits in different species. The presence of avian and swine influenza virus genes in the 2009 novel H1N1 pandemic virus (pH1N1) raises the potential for infection in poultry following exposur...

  15. Changes in H3 influenza A virus receptor specificity during replication in humans.

    PubMed

    Ryan-Poirier, K; Suzuki, Y; Bean, W J; Kobasa, D; Takada, A; Ito, T; Kawaoka, Y

    1998-08-01

    Influenza A viruses of the H3 subtype caused the 1968 Hong Kong pandemic, the hemagglutinin (HA) gene being introduced into humans following a reassortment event with an avian virus. Receptor specificity and serum inhibitor sensitivity of the HA of influenza A viruses are linked to the host species. Human H3 viruses preferentially recognize N-acetyl sialic acid linked to galactose by alpha2,6 linkages (Neu5Acalpha2,6Gal) and are sensitive to serum inhibitors, whereas avian and equine viruses preferentially recognize Neu5Acalpha2,3Gal linkages and are resistant to serum inhibitors. We have examined the receptor specificity and serum inhibitor sensitivity of H3 human influenza A viruses from the time they were introduced into the human population to gain insight into the mechanism of viral molecular evolution and host tropism. All of the viruses were sensitive to neutralization and hemagglutination inhibition by horse serum. Early H3 viruses were resistant to pig and rabbit serum inhibitors. Viruses isolated after 1977 were uniformly sensitive to inhibition by pig and rabbit sera. The recognition of Neu5Acalpha2,3Gal or Neu5Acalpha2,6Gal linkages was not correlated with the serum sensitivity. These data showed that the receptor specificity of HA, measured as inhibitor sensitivity, has changed during replication in humans since its introduction from an avian virus. PMID:9783465

  16. Animal models for influenza virus pathogenesis, transmission, and immunology

    PubMed Central

    Thangavel, Rajagowthamee R.; Bouvier, Nicole M.

    2014-01-01

    In humans, infection with an influenza A or B virus manifests typically as an acute and self-limited upper respiratory tract illness characterized by fever, cough, sore throat, and malaise. However, influenza can present along a broad spectrum of disease, ranging from sub-clinical or even asymptomatic infection to a severe primary viral pneumonia requiring advanced medical supportive care. Disease severity depends upon the virulence of the influenza virus strain and the immune competence and previous influenza exposures of the patient. Animal models are used in influenza research not only to elucidate the viral and host factors that affect influenza disease outcomes in and spread among susceptible hosts, but also to evaluate interventions designed to prevent or reduce influenza morbidity and mortality in man. This review will focus on the three animal models currently used most frequently in influenza virus research -- mice, ferrets, and guinea pigs -- and discuss the advantages and disadvantages of each. PMID:24709389

  17. Cross talk between animal and human influenza viruses.

    PubMed

    Ozawa, Makoto; Kawaoka, Yoshihiro

    2013-01-01

    Although outbreaks of highly pathogenic avian influenza in wild and domestic birds have been posing the threat of a new influenza pandemic for the past decade, the first pandemic of the twenty-first century came from swine viruses. This fact emphasizes the complexity of influenza viral ecology and the difficulty of predicting influenza viral dynamics. Complete control of influenza viruses seems impossible. However, we must minimize the impact of animal and human influenza outbreaks by learning lessons from past experiences and recognizing the current status. Here, we review the most recent influenza virology data in the veterinary field, including aspects of zoonotic agents and recent studies that assess the pandemic potential of H5N1 highly pathogenic avian influenza viruses. PMID:25387011

  18. Mechanisms of Cross-protection by Influenza Virus M2-based Vaccines

    PubMed Central

    Lee, Yu-Na; Kim, Min-Chul; Lee, Young-Tae; Kim, Yu-Jin

    2015-01-01

    Current influenza virus vaccines are based on strain-specific surface glycoprotein hemagglutinin (HA) antigens and effective only when the predicted vaccine strains and circulating viruses are well-matched. The current strategy of influenza vaccination does not prevent the pandemic outbreaks and protection efficacy is reduced or ineffective if mutant strains emerge. It is of high priority to develop effective vaccines and vaccination strategies conferring a broad range of cross protection. The extracellular domain of M2 (M2e) is highly conserved among human influenza A viruses and has been utilized to develop new vaccines inducing cross protection against different subtypes of influenza A virus. However, immune mechanisms of cross protection by M2e-based vaccines still remain to be fully elucidated. Here, we review immune correlates and mechanisms conferring cross protection by M2e-based vaccines. Molecular and cellular immune components that are known to be involved in M2 immune-mediated protection include antibodies, B cells, T cells, alveolar macrophages, Fc receptors, complements, and natural killer cells. Better understanding of protective mechanisms by immune responses induced by M2e vaccination will help facilitate development of broadly cross protective vaccines against influenza A virus. PMID:26557805

  19. Live-attenuated influenza A virus vaccines using a B virus backbone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The currently FDA-licensed live attenuated influenza virus vaccine contains a trivalent mixture of types A (H1N1 and H3N2) and B vaccine viruses. The two A virus vaccines have the backbone of a cold-adapted influenza A virus and the B virus vaccine has the six backbone segments derived from a cold-...

  20. Characterization of the Localized Immune Response in the Respiratory Tract of Ferrets following Infection with Influenza A and B Viruses

    PubMed Central

    Carolan, Louise A.; Rockman, Steve; Borg, Kathryn; Guarnaccia, Teagan; Reading, Patrick; Mosse, Jennifer; Kelso, Anne; Barr, Ian

    2015-01-01

    ABSTRACT The burden of infection with seasonal influenza viruses is significant. Each year is typically characterized by the dominance of one (sub)type or lineage of influenza A or B virus, respectively. The incidence of disease varies annually, and while this may be attributed to a particular virus strain or subtype, the impacts of prior immunity, population differences, and variations in clinical assessment are also important. To improve our understanding of the impacts of seasonal influenza viruses, we directly compared clinical symptoms, virus shedding, and expression of cytokines, chemokines, and immune mediators in the upper respiratory tract (URT) of ferrets infected with contemporary A(H1N1)pdm09, A(H3N2), or influenza B virus. Gene expression in the lower respiratory tract (LRT) was also assessed. Clinical symptoms were minimal. Overall cytokine/chemokine profiles in the URT were consistent in pattern and magnitude between animals infected with influenza A and B viruses, and peak expression levels of interleukin-1α (IL-1α), IL-1β, IL-6, IL-12p40, alpha interferon (IFN-α), IFN-β, and tumor necrosis factor alpha (TNF-α) mRNAs correlated with peak levels of viral shedding. MCP1 and IFN-γ were expressed after the virus peak. Granzymes A and B and IL-10 reached peak expression as the virus was cleared and seroconversion was detected. Cytokine/chemokine gene expression in the LRT following A(H1N1)pdm09 virus infection reflected the observations seen for the URT but was delayed 2 or 3 days, as was virus replication. These data indicate that disease severities and localized immune responses following infection with seasonal influenza A and B viruses are similar, suggesting that other factors are likely to modulate the incidence and impact of seasonal influenza. IMPORTANCE Both influenza A and B viruses cocirculate in the human population, and annual influenza seasons are typically dominated by an influenza A virus subtype or an influenza B virus lineage

  1. Efficacy of canine influenza virus (H3N8) vaccine to decrease severity of clinical disease after co-challenge with canine influenza virus and Streptococcus equi subsp. Zooepidemicus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since first emerging into the North American canine population in 2004, canine influenza virus (CIV) subtype H3N8 has shown horizontal transmission among dogs, with a high level of adaptation to this species. Severity of disease is variable, and co-infection by other respiratory pathogens is an impo...

  2. Genetic analysis of H3N2 avian influenza viruses isolated from live poultry markets and poultry slaughterhouses in Shanghai, China in 2013.

    PubMed

    Yang, Dequan; Liu, Jian; Ju, Houbin; Ge, Feifei; Wang, Jian; Li, Xin; Zhou, Jinping; Liu, Peihong

    2015-08-01

    Five H3N2 avian influenza viruses (AIVs) were isolated from live poultry markets (LPMs) and poultry slaughterhouses in Shanghai, China in 2013. All viruses were characterized by whole-genome sequencing with subsequent genetic comparison and phylogenetic analysis. The hemagglutinin cleavage site of all viruses indicated that the five strains were low-pathogenic AIVs. Phylogenetic analysis of all eight viral genes showed that the five H3N2 viruses clustered in the Eurasian lineage of influenza viruses. The eight genes showed evidence of reassortment events between these H3 subtype viruses and other subtype viruses, especially H5 and H7 subtypes, probably in pigeons, domestic ducks, and wild birds. These findings emphasized the importance of AIV surveillance in LPMs and poultry slaughterhouses for understanding the genesis and emergence of novel reassortants with pandemic potential. PMID:25899857

  3. Ultrasensitive Electrochemical Immunoassay for Avian Influenza Subtype H5 Using Nanocomposite

    PubMed Central

    Xie, Zhixun; Huang, Jiaoling; Luo, Sisi; Xie, Zhiqin; Xie, Liji; Liu, Jiabo; Pang, Yaoshan; Deng, Xianwen; Fan, Qing

    2014-01-01

    We report a novel electrochemical immunosensor that can sensitively detect avian influenza virus H5 subtype (AIV H5) captured by graphene oxide-H5-polychonal antibodies-bovine serum albumin (GO-PAb-BSA) nanocomposite. The graphene oxide (GO) carried H5-polychonal antibody (PAb) were used as signal amplification materials. Upon signal amplification, the immunosensor showed a 256-fold increase in detection sensitivity compared to the immunosensor without GO-PAb-BSA. We designed a PAb labeling GO strategy and signal amplification procedure that allow ultrasensitive and selective detection of AIV H5. The established method responded to 2−15 HA unit/50 µL H5, with a linear calibration range from 2−15 to 2−8 HA unit/50 µL. In summary, we demonstrated that the immunosenser has a high specificity and sensitivity for AIV H5, and the established assay could be potentially applied in the rapid detection of other pathogenic microorganisms. PMID:24733043

  4. The global antigenic diversity of swine influenza A viruses.

    PubMed

    Lewis, Nicola S; Russell, Colin A; Langat, Pinky; Anderson, Tavis K; Berger, Kathryn; Bielejec, Filip; Burke, David F; Dudas, Gytis; Fonville, Judith M; Fouchier, Ron Am; Kellam, Paul; Koel, Bjorn F; Lemey, Philippe; Nguyen, Tung; Nuansrichy, Bundit; Peiris, Js Malik; Saito, Takehiko; Simon, Gaelle; Skepner, Eugene; Takemae, Nobuhiro; Webby, Richard J; Van Reeth, Kristien; Brookes, Sharon M; Larsen, Lars; Watson, Simon J; Brown, Ian H; Vincent, Amy L

    2016-01-01

    Swine influenza presents a substantial disease burden for pig populations worldwide and poses a potential pandemic threat to humans. There is considerable diversity in both H1 and H3 influenza viruses circulating in swine due to the frequent introductions of viruses from humans and birds coupled with geographic segregation of global swine populations. Much of this diversity is characterized genetically but the antigenic diversity of these viruses is poorly understood. Critically, the antigenic diversity shapes the risk profile of swine influenza viruses in terms of their epizootic and pandemic potential. Here, using the most comprehensive set of swine influenza virus antigenic data compiled to date, we quantify the antigenic diversity of swine influenza viruses on a multi-continental scale. The substantial antigenic diversity of recently circulating viruses in different parts of the world adds complexity to the risk profiles for the movement of swine and the potential for swine-derived infections in humans. PMID:27113719

  5. Influenza viruses in adult dogs raised in rural and urban areas in the state of São Paulo, Brazil.

    PubMed

    Mancini, Dalva Assunção Portari; Mendonça, Rita Maria Zucatelli; Pereira, Aparecida Santo Pietro; Kawamoto, Adélia Hiroko Nagamori; Vannucchi, Camila Infantosi; Pinto, José Ricardo; Mori, Enio; Mancini Filho, Jorge

    2012-12-01

    In 1970, searching for the interspecies transmission of influenza viruses led to the first study on influenza viruses in domestic animals. Birds and mammals, including human beings, are their natural hosts; however, other animals may also play a role in the virus epidemiology. The objective was to investigate the incidence of influenza viruses in adult dogs raised in rural (9, 19.56%) and urban (37, 80.43%) areas in the state of São Paulo, Brazil. Dog serum samples were examined for antibodies to influenza viruses by the hemagglutination inhibition (HI) test using the corresponding antigens from the circulating viruses in Brazil. Dogs from rural areas presented antibodies to influenza A H3N2, and influenza A H7N7 and H3N8. In rural areas, dog sera displayed mean titers as 94.37, 227.88, 168.14, 189.62 HIU/25 µL for subtypes H1N1, H3N2, H7N7, H3N8, respectively. About 84% and 92% of dogs from urban areas exhibited antibodies to human influenza A H1N1 and H3N2, respectively, with statistical difference at p < 0.05 between the mean titers of antibodies to H1N1 and H3N2. About 92% and 100% were positive for H7N7 and H3N8, respectively. In dogs from urban areas, the mean titers of antibodies against influenza A H1N1, H3N2, H7N7 and H3N8, were 213.96, 179.42, 231.76, 231.35 HIU/25 µL respectively. The difference among them was not statistically significant at p > 0.05. In conclusion, these dogs were positive for both human and equine influenza viruses. The present study suggests the first evidence that influenza viruses circulate among dogs in Brazil. PMID:23152313

  6. Adaptation of high-growth influenza H5N1 vaccine virus in Vero cells: implications for pandemic preparedness.

    PubMed

    Tseng, Yu-Fen; Hu, Alan Yung-Chih; Huang, Mei-Liang; Yeh, Wei-Zhou; Weng, Tsai-Chuan; Chen, Yu-Shuan; Chong, Pele; Lee, Min-Shi

    2011-01-01

    Current egg-based influenza vaccine production technology can't promptly meet the global demand during an influenza pandemic as shown in the 2009 H1N1 pandemic. Moreover, its manufacturing capacity would be vulnerable during pandemics caused by highly pathogenic avian influenza viruses. Therefore, vaccine production using mammalian cell technology is becoming attractive. Current influenza H5N1 vaccine strain (NIBRG-14), a reassortant virus between A/Vietnam/1194/2004 (H5N1) virus and egg-adapted high-growth A/PR/8/1934 virus, could grow efficiently in eggs and MDCK cells but not Vero cells which is the most popular cell line for manufacturing human vaccines. After serial passages and plaque purifications of the NIBRG-14 vaccine virus in Vero cells, one high-growth virus strain (Vero-15) was generated and can grow over 10(8) TCID(50)/ml. In conclusion, one high-growth H5N1 vaccine virus was generated in Vero cells, which can be used to manufacture influenza H5N1 vaccines and prepare reassortant vaccine viruses for other influenza A subtypes. PMID:22022351

  7. Influenza virus vaccine for neglected hosts: horses and dogs.

    PubMed

    Na, Woonsung; Yeom, Minjoo; Yuk, Huijoon; Moon, Hyoungjoon; Kang, Bokyu; Song, Daesub

    2016-07-01

    This study provides information regarding vaccine research and the epidemiology of influenza virus in neglected hosts (horses and dogs). Equine influenza virus (EIV) causes a highly contagious disease in horses and other equids, and outbreaks have occurred worldwide. EIV has resulted in costly damage to the horse industry and has the ability of cross the host species barrier from horses to dogs. Canine influenza is a virus of equine or avian origin and infects companion animals that live in close contact with humans; this results in possible exposure to the seasonal epizootic influenza virus. There have been case reports of genetic reassortment between human and canine influenza viruses, which results in high virulence and the ability of transmission to ferrets. This emphasizes the need for vaccine research on neglected hosts to update knowledge on current strains and to advance technology for controlling influenza outbreaks for public health. PMID:27489801

  8. Influenza virus vaccine for neglected hosts: horses and dogs

    PubMed Central

    2016-01-01

    This study provides information regarding vaccine research and the epidemiology of influenza virus in neglected hosts (horses and dogs). Equine influenza virus (EIV) causes a highly contagious disease in horses and other equids, and outbreaks have occurred worldwide. EIV has resulted in costly damage to the horse industry and has the ability of cross the host species barrier from horses to dogs. Canine influenza is a virus of equine or avian origin and infects companion animals that live in close contact with humans; this results in possible exposure to the seasonal epizootic influenza virus. There have been case reports of genetic reassortment between human and canine influenza viruses, which results in high virulence and the ability of transmission to ferrets. This emphasizes the need for vaccine research on neglected hosts to update knowledge on current strains and to advance technology for controlling influenza outbreaks for public health. PMID:27489801

  9. Heterosubtypic Antibodies to Influenza A Virus Have Limited Activity against Cell-Bound Virus but Are Not Impaired by Strain-Specific Serum Antibodies

    PubMed Central

    Wyrzucki, Arkadiusz; Bianchi, Matteo; Kohler, Ines; Steck, Marco

    2014-01-01

    ABSTRACT The majority of influenza virus-specific antibodies elicited by vaccination or natural infection are effective only against the eliciting or closely related viruses. Rare stem-specific heterosubtypic monoclonal antibodies (hMAbs) can neutralize multiple strains and subtypes by preventing hemagglutinin (HA)-mediated fusion of the viral membrane with the endosomal membrane. The epitopes recognized by these hMAbs are therefore considered promising targets for the development of pan-influenza virus vaccines. Here, we report the isolation of a novel human HA stem-reactive monoclonal antibody, hMAb 1.12, with exceptionally broad neutralizing activity encompassing viruses from 15 distinct HA subtypes. Using MAb 1.12 and two other monoclonal antibodies, we demonstrate that neutralization by hMAbs is virtually irreversible but becomes severely impaired following virus attachment to cells. In contrast, no interference by human anti-influenza virus serum antibodies was found, indicating that apically binding antibodies do not impair access to the membrane-proximal heterosubtypic epitopes. Our findings therefore encourage development of new vaccine concepts aiming at the induction of stem-specific heterosubtypic antibodies, as we provide support for their effectiveness in individuals previously exposed to influenza virus. IMPORTANCE The influenza A virus hemagglutinin (HA) can easily accommodate changes in its antigenic structures to escape preexisting immunity. This variability restricts the breadth and long-term efficacy of influenza vaccines. Only a few heterosubtypic antibodies (hMAbs), i.e., antibodies that can neutralize more than one subtype of influenza A virus, have been identified. The molecular interactions between these heterosubtypic antibodies and hemagglutinin are well characterized, yet little is known about the functional properties of these antibodies. Using a new, extraordinarily broad hMAb, we show that virus neutralization by hMAbs is virtually

  10. Avian Influenza Virus and DIVA Strategies.

    PubMed

    Hasan, Noor Haliza; Ignjatovic, Jagoda; Peaston, Anne; Hemmatzadeh, Farhid

    2016-05-01

    Vaccination is becoming a more acceptable option in the effort to eradicate avian influenza viruses (AIV) from commercial poultry, especially in countries where AIV is endemic. The main concern surrounding this option has been the inability of the conventional serological tests to differentiate antibodies produced due to vaccination from antibodies produced in response to virus infection. In attempts to address this issue, at least six strategies have been formulated, aiming to differentiate infected from vaccinated animals (DIVA), namely (i) sentinel birds, (ii) subunit vaccine, (iii) heterologous neuraminidase (NA), (iv) nonstructural 1 (NS1) protein, (v) matrix 2 ectodomain (M2e) protein, and (vi) haemagglutinin subunit 2 (HA2) glycoprotein. This short review briefly discusses the strengths and limitations of these DIVA strategies, together with the feasibility and practicality of the options as a part of the surveillance program directed toward the eventual eradication of AIV from poultry in countries where highly pathogenic avian influenza is endemic. PMID:26900835

  11. The molecular determinants of antibody recognition and antigenic drift in the H3 hemagglutinin of swine influenza A virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Influenza A virus (IAV) of the H3 subtype is an important pathogen that affects both humans and swine. The main intervention strategy for preventing infection is vaccination to induce neutralizing antibodies against the surface glycoprotein hemagglutinin (HA). However, due to antigenic drift, vaccin...

  12. Lack of antigenic diversity in contemporary H7 avian-origin influenza A viruses from North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Subtype H7 avian–origin influenza A viruses (AIVs) have caused at least 500 confirmed human infections since 2003 and culling of >75 million birds in recent years. Understanding the antigenic diversity and genetic evolution of H7 AIVs is critical for developing effective strategies for disease prev...

  13. First Characterization of Avian Influenza Viruses from Greenland 2014.

    PubMed

    Hartby, Christina Marie; Krog, Jesper Schak; Merkel, Flemming; Holm, Elisabeth; Larsen, Lars Erik; Hjulsager, Charlotte Kristiane

    2016-05-01

    In late February 2014, unusually high numbers of wild thick-billed murres (Uria lomvia) were found dead on the coast of South Greenland. To investigate the cause of death, 45 birds were submitted for laboratory examination in Denmark. Avian influenza viruses (AIVs) with subtypes H11N2 and low pathogenic H5N1 were detected in some of the birds. Characterization of the viruses by full genome sequencing revealed that all the gene segments belonged to the North American lineage of AIVs. The seemingly sparse and mixed subtype occurrence of low pathogenic AIVs in these birds, in addition to the emaciated appearance of the birds, suggests that the murre die-off was due to malnutrition as a result of sparse food availability or inclement weather. Here we present the first characterization of AIVs isolated in Greenland, and our results support the idea that wild birds in Greenland may be involved in the movement of AIV between North America and Europe. PMID:27309071

  14. Evaluation of the immunogenicity and protective effects of a trivalent chimeric norovirus P particle immunogen displaying influenza HA2 from subtypes H1, H3 and B.

    PubMed

    Gong, Xin; Yin, He; Shi, Yuhua; He, Xiaoqiu; Yu, Yongjiao; Guan, Shanshan; Kuai, Ziyu; Haji, Nasteha M; Haji, Nafisa M; Kong, Wei; Shan, Yaming

    2016-01-01

    The ectodomain of the influenza A virus (IAV) hemagglutinin (HA) stem is highly conserved across strains and has shown promise as a universal influenza vaccine in a mouse model. In this study, potential B-cell epitopes were found through sequence alignment and epitope prediction in a stem fragment, HA2:90-105, which is highly conserved among virus subtypes H1, H3 and B. A norovirus (NoV) P particle platform was used to express the HA2:90-105 sequences from subtypes H1, H3 and B in loops 1, 2 and 3 of the protrusion (P) domain, respectively. Through mouse immunization and microneutralization assays, the immunogenicity and protective efficacy of the chimeric NoV P particle (trivalent HA2-PP) were tested against infection with three subtypes (H1N1, H3N2 and B) of IAV in Madin-Darby canine kidney cells. The protective efficacy of the trivalent HA2-PP was also evaluated preliminarily in vivo by virus challenge in the mouse model. The trivalent HA2-PP immunogen induced significant IgG antibody responses, which could be enhanced by a virus booster vaccination. Moreover, the trivalent HA2-PP immunogen also demonstrated in vitro neutralization of the H3 and B viruses, and in vivo protection against the H3 virus. Our results support the notion that a broadly protective vaccine approach using an HA2-based NoV P particle platform can provide cross-protection against challenge viruses of different IAV subtypes. The efficacy of the immunogen should be further enhanced for practicality, and a better understanding of the protective immune mechanism will be critical for the development of HA2-based multivalent vaccines. PMID:27222326

  15. Evaluation of the immunogenicity and protective effects of a trivalent chimeric norovirus P particle immunogen displaying influenza HA2 from subtypes H1, H3 and B

    PubMed Central

    Gong, Xin; Yin, He; Shi, Yuhua; He, Xiaoqiu; Yu, Yongjiao; Guan, Shanshan; Kuai, Ziyu; Haji, Nasteha M; Haji, Nafisa M; Kong, Wei; Shan, Yaming

    2016-01-01

    The ectodomain of the influenza A virus (IAV) hemagglutinin (HA) stem is highly conserved across strains and has shown promise as a universal influenza vaccine in a mouse model. In this study, potential B-cell epitopes were found through sequence alignment and epitope prediction in a stem fragment, HA2:90-105, which is highly conserved among virus subtypes H1, H3 and B. A norovirus (NoV) P particle platform was used to express the HA2:90-105 sequences from subtypes H1, H3 and B in loops 1, 2 and 3 of the protrusion (P) domain, respectively. Through mouse immunization and microneutralization assays, the immunogenicity and protective efficacy of the chimeric NoV P particle (trivalent HA2-PP) were tested against infection with three subtypes (H1N1, H3N2 and B) of IAV in Madin–Darby canine kidney cells. The protective efficacy of the trivalent HA2-PP was also evaluated preliminarily in vivo by virus challenge in the mouse model. The trivalent HA2-PP immunogen induced significant IgG antibody responses, which could be enhanced by a virus booster vaccination. Moreover, the trivalent HA2-PP immunogen also demonstrated in vitro neutralization of the H3 and B viruses, and in vivo protection against the H3 virus. Our results support the notion that a broadly protective vaccine approach using an HA2-based NoV P particle platform can provide cross-protection against challenge viruses of different IAV subtypes. The efficacy of the immunogen should be further enhanced for practicality, and a better understanding of the protective immune mechanism will be critical for the development of HA2-based multivalent vaccines. PMID:27222326

  16. Agar gel immunodiffusion assay to detect antibodies to Type A influenza virus.

    PubMed

    Jenson, Terra A

    2014-01-01

    The agar gel immunodiffusion (AGID) test is used to detect antibodies to Type A influenza group-specific antigens, i.e., the ribonucleoprotein (RNP) and matrix (M) proteins. Therefore, this test will detect antibodies to all influenza A virus subtypes. AGID is commonly used to screen poultry flocks for avian influenza virus infection. The AGID is a simple and economical serological test. All serological testing has its advantages and disadvantages which should be considered before choosing the optimal test for the laboratory needs. Each laboratory must evaluate the laboratory's resources, the volume of testing, the goal of testing, how the test results are used and what types of samples are being tested in order to select the optimal test. PMID:24899427

  17. A Single Dose of an Avian H3N8 Influenza Virus Vaccine Is Highly Immunogenic and Efficacious against a Recently Emerged Seal Influenza Virus in Mice and Ferrets

    PubMed Central

    Baz, Mariana; Paskel, Myeisha; Matsuoka, Yumiko; Zengel, James R.; Cheng, Xing; Treanor, John J.; Jin, Hong

    2015-01-01

    ABSTRACT H3N8 influenza viruses are a commonly found subtype in wild birds, usually causing mild or no disease in infected birds. However, they have crossed the species barrier and have been associated with outbreaks in dogs, pigs, donkeys, and seals and therefore pose a threat to humans. A live attenuated, cold-adapted (ca) H3N8 vaccine virus was generated by reverse genetics using the wild-type (wt) hemagglutinin (HA) and neuraminidase (NA) genes from the A/blue-winged teal/Texas/Sg-00079/2007 (H3N8) (tl/TX/079/07) wt virus and the six internal protein gene segments from the ca influenza A virus vaccine donor strain, A/Ann Arbor/6/60 ca (H2N2), the backbone of the licensed seasonal live attenuated influenza vaccine. One dose of the tl/TX/079/07 ca vaccine induced a robust neutralizing antibody response against the homologous (tl/TX/079/07) and two heterologous influenza viruses, including the recently emerged A/harbor seal/New Hampshire/179629/2011 (H3N8) and A/northern pintail/Alaska/44228-129/2006 (H3N8) viruses, and conferred robust protection against the homologous and heterologous influenza viruses. We also analyzed human sera against the tl/TX/079/07 H3N8 avian influenza virus and observed low but detectable antibody reactivity in elderly subjects, suggesting that older H3N2 influenza viruses confer some cross-reactive antibody. The latter observation was confirmed in a ferret study. The safety, immunogenicity, and efficacy of the tl/TX/079/07 ca vaccine in mice and ferrets support further evaluation of this vaccine in humans for use in the event of transmission of an H3N8 avian influenza virus to humans. The human and ferret serology data suggest that a single dose of the vaccine may be sufficient in older subjects. IMPORTANCE Although natural infection of humans with an avian H3N8 influenza virus has not yet been reported, this influenza virus subtype has already crossed the species barrier and productively infected mammals. Pandemic preparedness is an

  18. Comparison of three serological assays to determine the cross-reactivity of antibodies from eight genetically diverse U.S. swine influenza viruses.

    PubMed

    Leuwerke, Brad; Kitikoon, Pravina; Evans, Richard; Thacker, Eileen

    2008-07-01

    Swine influenza virus is an economically important pathogen to the U.S. swine industry. New influenza subtypes and isolates within subtypes with different genetic and antigenic makeup have recently emerged in U.S. swineherds. As a result of the emergence of these new viruses, diagnosticians' ability to accurately diagnose influenza infection in pigs and develop appropriate vaccine strategies has become increasingly difficult. The current study compares the ability of subtype-specific commercial enzyme-linked immunosorbent assays (ELISA), hemagglutination inhibition (HI), and serum neutralization (SN) assays to detect antibodies elicited by multiple isolates within different subtypes of influenza virus. Pigs were infected with genetically and antigenically different isolates of the 3 major circulating subtypes within populations of swine (H1N1, H1N2, and H3N2). Serum was collected when all pigs within a group collectively reached HI reciprocal titers >or=160 against that group's homologous challenge virus. The antibody cross-reactivity of the sera between isolates was determined using ELISA, HI, and SN assays. In addition, the correlation between the 3 assays was determined. The assays differed in their ability to detect antibodies produced by the viruses used in the study. The results provide important information to diagnostic laboratories, veterinarians, and swine producers on the ability of 3 common serological assays used in identifying infection with influenza in pigs. PMID:18599846

  19. A recombinant influenza virus vaccine expressing the F protein of respiratory syncytial virus

    PubMed Central

    Fonseca, Wendy; Ozawa, Makoto; Hatta, Masato; Orozco, Esther; Martínez, Máximo B; Kawaoka, Yoshihiro

    2014-01-01

    Infections with influenza and respiratory syncytial virus (RSV) rank high among the most common human respiratory diseases worldwide. Previously, we developed a replication-incompetent influenza virus by replacing the coding sequence of the PB2 gene, which encodes one of the viral RNA polymerase subunits, with that of a reporter gene. Here, we generated a PB2-knockout recombinant influenza virus expressing the F protein of RSV (PB2-RSVF virus) and tested its potential as a bivalent vaccine. In mice intranasally immunized with the PB2-RSVF virus, we detected high levels of antibodies against influenza virus, but not RSV. PB2-RSVF virus-immunized mice were protected from a lethal challenge with influenza virus but experienced severe body weight loss when challenged with RSV, indicating that PB2-RSVF vaccination enhanced RSV-associated disease. These results highlight one of the difficulties of developing an effective bivalent vaccine against influenza virus and RSV infections. PMID:24292020

  20. Sequential Infection in Ferrets with Antigenically Distinct Seasonal H1N1 Influenza Viruses Boosts Hemagglutinin Stalk-Specific Antibodies

    PubMed Central

    Kirchenbaum, Greg A.; Carter, Donald M.

    2015-01-01

    ABSTRACT Broadly reactive antibodies targeting the conserved hemagglutinin (HA) stalk region are elicited following sequential infection or vaccination with influenza viruses belonging to divergent subtypes and/or expressing antigenically distinct HA globular head domains. Here, we demonstrate, through the use of novel chimeric HA proteins and competitive binding assays, that sequential infection of ferrets with antigenically distinct seasonal H1N1 (sH1N1) influenza virus isolates induced an HA stalk-specific antibody response. Additionally, stalk-specific antibody titers were boosted following sequential infection with antigenically distinct sH1N1 isolates in spite of preexisting, cross-reactive, HA-specific antibody titers. Despite a decline in stalk-specific serum antibody titers, sequential sH1N1 influenza virus-infected ferrets were protected from challenge with a novel H1N1 influenza virus (A/California/07/2009), and these ferrets poorly transmitted the virus to naive contacts. Collectively, these findings indicate that HA stalk-specific antibodies are commonly elicited in ferrets following sequential infection with antigenically distinct sH1N1 influenza virus isolates lacking HA receptor-binding site cross-reactivity and can protect ferrets against a pathogenic novel H1N1 virus. IMPORTANCE The influenza virus hemagglutinin (HA) is a major target of the humoral immune response following infection and/or seasonal vaccination. While antibodies targeting the receptor-binding pocket of HA possess strong neutralization capacities, these antibodies are largely strain specific and do not confer protection against antigenic drift variant or novel HA subtype-expressing viruses. In contrast, antibodies targeting the conserved stalk region of HA exhibit broader reactivity among viruses within and among influenza virus subtypes. Here, we show that sequential infection of ferrets with antigenically distinct seasonal H1N1 influenza viruses boosts the antibody responses

  1. Influenza A virus infections in marine mammals and terrestrial carnivores.

    PubMed

    Harder, Timm C; Siebert, Ursula; Wohlsein, Peter; Vahlenkamp, Thomas

    2013-01-01

    Influenza A viruses (IAV), members of the Orthomyxoviridae, cover a wide host spectrum comprising a plethora of avian and, in comparison, a few mammalian species. The viral reservoir and gene pool are kept in metapopulations of aquatic wild birds. The mammalian-adapted IAVs originally arose by transspecies transmission from avian sources. In swine, horse and man, species-adapted IAV lineages circulate independently of the avian reservoir and cause predominantly respiratory disease of highly variable severity. Sporadic outbreaks of IAV infections associated with pneumonic clinical signs have repeatedly occurred in marine mammals (harbour seals [Phoca vitulina]) off the New England coast of the U.S.A. due to episodic transmission of avian IAV. However, no indigenous marine mammal IAV lineages are described. In contrast to marine mammals, avian- and equine-derived IAVs have formed stable circulating lineages in terrestrial carnivores: IAVs of subtype H3N2 and H3N8 are found in canine populations in South Korea, China, and the U.S.A. Experimental infections revealed that dogs and cats can be infected with an even wider range of avian IAVs. Cats, in particular, also proved susceptible to native infection with human pandemic H1N1 viruses and, according to serological data, may be vulnerable to infection with further human-adapted IAVs. Ferrets are susceptible to a variety of avian and mammalian IAVs and are an established animal model of human IAV infection. Thus, a potential role of pet cats, dogs and ferrets as mediators of avian-derived viruses to the human population does exist. A closer observation for influenza virus infections and transmissions at this animal-human interface is indicated. PMID:24511825

  2. Antigenic and genomic characterization of human influenza A and B viruses circulating in Argentina after the introduction of influenza A(H1N1)pdm09.

    PubMed

    Russo, Mara L; Pontoriero, Andrea V; Benedetti, Estefania; Czech, Andrea; Avaro, Martin; Periolo, Natalia; Campos, Ana M; Savy, Vilma L; Baumeister, Elsa G

    2014-12-01

    This study was conducted as part of the Argentinean Influenza and other Respiratory Viruses Surveillance Network, in the context of the Global Influenza Surveillance carried out by the World Health Organization (WHO). The objective was to study the activity and the antigenic and genomic characteristics of circulating viruses for three consecutive seasons (2010, 2011 and 2012) in order to investigate the emergence of influenza viral variants. During the study period, influenza virus circulation was detected from January to December. Influenza A and B, and all current subtypes of human influenza viruses, were present each year. Throughout the 2010 post-pandemic season, influenza A(H1N1)pdm09, unexpectedly, almost disappeared. The haemagglutinin (HA) of the A(H1N1)pdm09 viruses studied were segregated in a different genetic group to those identified during the 2009 pandemic, although they were still antigenically closely related to the vaccine strain A/California/07/2009. Influenza A(H3N2) viruses were the predominant strains circulating during the 2011 season, accounting for nearly 76 % of influenza viruses identified. That year, all HA sequences of the A(H3N2) viruses tested fell into the A/Victoria/208/2009 genetic clade, but remained antigenically related to A/Perth/16/2009 (reference vaccine recommended for this three-year period). A(H3N2) viruses isolated in 2012 were antigenically closely related to A/Victoria/361/2011, recommended by the WHO as the H3 component for the 2013 Southern Hemisphere formulation. B viruses belonging to the B/Victoria lineage circulated in 2010. A mixed circulation of viral variants of both B/Victoria and B/Yamagata lineages was detected in 2012, with the former being predominant. A(H1N1)pdm09 viruses remained antigenically closely related to the vaccine virus A/California/7/2009; A(H3N2) viruses continually evolved into new antigenic clusters and both B lineages, B/Victoria/2/87-like and B/Yamagata/16/88-like viruses, were observed

  3. Attenuation of human influenza a viruses

    PubMed Central

    Beare, A. S.; Bynoe, M. L.

    1969-01-01

    The attenuation of two human influenza A viruses has been carried out, using the selection of inhibitor-resistant strains and multiple passages at low temperatures. A virus related to A2/Tokyo/3/67 was obtained in an inhibitor-resistant form. When this was compared with the inhibitor-sensitive strain in a volunteer trial it was relatively non-pathogenic. The second virus, A2/Hongkong/1/68, was subjected to much longer treatment, but nevertheless remained slightly sensitive to serum inhibitor. When given to volunteers it was less pathogenic than before but attenuation was incomplete. A2/Hongkong/1/68 was also modified by passage at low temperatures. Many of these passages are apparently necessary for full attenuation. All attenuated viruses were infective and antigenic. PMID:4900146

  4. Global update on the susceptibility of human influenza viruses to neuraminidase inhibitors, 2012-2013.

    PubMed

    Meijer, Adam; Rebelo-de-Andrade, Helena; Correia, Vanessa; Besselaar, Terry; Drager-Dayal, Renu; Fry, Alicia; Gregory, Vicky; Gubareva, Larisa; Kageyama, Tsutomu; Lackenby, Angie; Lo, Janice; Odagiri, Takato; Pereyaslov, Dmitriy; Siqueira, Marilda M; Takashita, Emi; Tashiro, Masato; Wang, Dayan; Wong, Sun; Zhang, Wenqing; Daniels, Rod S; Hurt, Aeron C

    2014-10-01

    Emergence of influenza viruses with reduced susceptibility to neuraminidase inhibitors (NAIs) is sporadic, often follows exposure to NAIs, but occasionally occurs in the absence of NAI pressure. The emergence and global spread in 2007/2008 of A(H1N1) influenza viruses showing clinical resistance to oseltamivir due to neuraminidase (NA) H275Y substitution, in the absence of drug pressure, warrants continued vigilance and monitoring for similar viruses. Four World Health Organization (WHO) Collaborating Centres for Reference and Research on Influenza and one WHO Collaborating Centre for the Surveillance, Epidemiology and Control of Influenza (WHO CCs) tested 11,387 viruses collected by WHO-recognized National Influenza Centres (NIC) between May 2012 and May 2013 to determine 50% inhibitory concentration (IC50) data for oseltamivir, zanamivir, peramivir and laninamivir. The data were evaluated using normalized IC50 fold-changes rather than raw IC50 data. Nearly 90% of the 11,387 viruses were from three WHO regions: Western Pacific, the Americas and Europe. Only 0.2% (n=27) showed highly reduced inhibition (HRI) against at least one of the four NAIs, usually oseltamivir, while 0.3% (n=39) showed reduced inhibition (RI). NA sequence data, available from the WHO CCs and from sequence databases (n=3661), were screened for amino acid substitutions associated with reduced NAI susceptibility. Those showing HRI were A(H1N1)pdm09 with NA H275Y (n=18), A(H3N2) with NA E119V (n=3) or NA R292K (n=1) and B/Victoria-lineage with NA H273Y (n=2); amino acid position numbering is A subtype and B type specific. Overall, approximately 99% of circulating viruses tested during the 2012-2013 period were sensitive to all four NAIs. Consequently, these drugs remain an appropriate choice for the treatment and prophylaxis of influenza virus infections. PMID:25043638

  5. Influenza virus infection, ozone exposure, and fibrogenesis.

    PubMed

    Jakab, G J; Bassett, D J

    1990-05-01

    Oxidant exposure following chemically induced lung injury exacerbates the tendency to develop pulmonary fibrosis. Influenza virus pneumonitis causes severe acute lung damage that, upon resolution, is followed by a persistent alveolitis and parenchymal changes characterized by patchy interstitial pneumonia and collagen deposition in the affected areas. To determine whether oxidant exposure exacerbates the virus-induced alveolitis and residual lung damage, mice were infected by aerosol inhalation with influenza A virus and continuously exposed to 0.5 ppm ozone or ambient air. Noninfected control mice were exposed to either ambient air or ozone. On various days during the first month after infection, groups of mice were sacrificed and their lungs assessed for acute injury (lung lavage albumin, total and differential cell counts, wet/dry ratios, and morphometry). At 30, 60, 90, and 120 days after infection, groups of mice were sacrificed for total and differential lavage cell counts, lung hydroxyproline content, and morphometric analysis. Ozone exposure did not alter the proliferation of virus in the lungs as quantitated by infectious virus titers of lung homogenates at 1, 4, 7, 10, and 15 days after virus infection but mitigated the virus-induced acute lung injury by approximately 50%. After Day 30 a shift in the character of the pulmonary lesions was observed in that continuous exposure to ozone potentiated the postinfluenzal alveolitis and structural changes in the lung parenchyma. Additional studies suggest that the mechanism for the enhanced postinfluenzal lung damage may be related to the oxidant impairing the repair process of the acute influenzal lung damage. These data demonstrate that ozone exposure mitigates acute virus-induced lung injury and potentiates residual lung damage. PMID:2339849

  6. Neuraminidase inhibitors for influenza B virus infection: efficacy and resistance

    PubMed Central

    Burnham, Andrew J.; Baranovich, Tatiana; Govorkova, Elena A.

    2013-01-01

    Many aspects of the biology and epidemiology of influenza B viruses are far less studied than for influenza A viruses, and one of these aspects is effectiveness and resistance to the clinically available antiviral drugs, the neuraminidase (NA) inhibitors (NAIs). Acute respiratory infections are one of the leading causes of death in children and adults, and influenza is among the few respiratory infections that can be prevented and treated by vaccination and antiviral treatment. Recent data has suggested that influenza B virus infections are of specific concern to pediatric patients because of the increased risk of severe disease. Treatment of influenza B is a challenging task for the following reasons: NAIs (e.g., oseltamivir and zanamivir) are the only FDA-approved class of antivirals available for treatment;the data suggest that oseltamivir is less effective than zanamivir in pediatric patients;zanamivir is not prescribed to patients younger than 7;influenza B viruses are less susceptible than influenza A viruses to NAIs in vitro;although the level of resistance to NAIs is low, the number of different molecular markers of resistance is higher than for influenza A viruses, and they are not well defined;the relationship between levels of NAI phenotypic resistance and known molecular markers, frequency of emergence, transmissibility, and fitness of NAI-resistant variants are not well established. This review presents current knowledge of the effectiveness of NAIs for influenza B virus and antiviral resistance in clinical, surveillance, and experimental studies. PMID:24013000

  7. Characterization of influenza virus among influenza like illness cases in Mumbai, India.

    PubMed

    Roy, Soumen; Dahake, Ritwik; Patil, Deepak; Tawde, Shweta; Mukherjee, Sandeepan; Athlekar, Shrikant; Chowdhary, Abhay; Deshmukh, Ranjana

    2014-01-01

    The present study was carried out to monitor influenza viruses by identifying the virus and studying the seasonal variation during 2007-2009 in Mumbai. A total of 193 clinical respiratory samples (nasal and throat swab) were collected from patients having influenza like illness in Mumbai region. One-step real-time reverse-transcriptase PCR (rRTPCR) was used to detect Influenza type A (H1 and H3) and Influenza type B virus. Isolation of the virus was carried out using in vitro system which was further confirmed and typed by hemagglutination assay and hemagglutination inhibition assay. Out of 193 samples 24 (12.4 3%) samples tested positive for influenza virus, of which 13 (6.73 %) were influenza type A virus and 10 (5.18 %) were influenza type B virus, while 1 sample (0.51 %) was positive for both. By culture methods, 3 (1.55 %) viral isolates were obtained. All the three isolates were found to be Influenza type B/Malaysia (Victoria lineage) by Hemagglutination Inhibition Assay. The data generated from the present study reveals that both Influenza type A and B are prevalent in Mumbai with considerable activity. The peak activity was observed during monsoon season. PMID:25674606

  8. Prevalence and control of H7 avian influenza viruses in birds and humans.

    PubMed

    Abdelwhab, E M; Veits, J; Mettenleiter, T C

    2014-05-01

    The H7 subtype HA gene has been found in combination with all nine NA subtype genes. Most exhibit low pathogenicity and only rarely high pathogenicity in poultry (and humans). During the past few years infections of poultry and humans with H7 subtypes have increased markedly. This review summarizes the emergence of avian influenza virus H7 subtypes in birds and humans, and the possibilities of its control in poultry. All H7Nx combinations were reported from wild birds, the natural reservoir of the virus. Geographically, the most prevalent subtype is H7N7, which is endemic in wild birds in Europe and was frequently reported in domestic poultry, whereas subtype H7N3 is mostly isolated from the Americas. In humans, mild to fatal infections were caused by subtypes H7N2, H7N3, H7N7 and H7N9. While infections of humans have been associated mostly with exposure to domestic poultry, infections of poultry have been linked to wild birds or live-bird markets. Generally, depopulation of infected poultry was the main control tool; however, inactivated vaccines were also used. In contrast to recent cases caused by subtype H7N9, human infections were usually self-limiting and rarely required antiviral medication. Close genetic and antigenic relatedness of H7 viruses of different origins may be helpful in development of universal vaccines and diagnostics for both animals and humans. Due to the wide spread of H7 viruses and their zoonotic importance more research is required to better understand the epidemiology, pathobiology and virulence determinants of these viruses and to develop improved control tools. PMID:24423384

  9. Modified Vaccinia Virus Ankara (MVA) as Production Platform for Vaccines against Influenza and Other Viral Respiratory Diseases

    PubMed Central

    Altenburg, Arwen F.; Kreijtz, Joost H. C. M.; de Vries, Rory D.; Song, Fei; Fux, Robert; Rimmelzwaan, Guus F.; Sutter, Gerd; Volz, Asisa

    2014-01-01

    Respiratory viruses infections caused by influenza viruses, human parainfluenza virus (hPIV), respiratory syncytial virus (RSV) and coronaviruses are an eminent threat for public health. Currently, there are no licensed vaccines available for hPIV, RSV and coronaviruses, and the available seasonal influenza vaccines have considerable limitations. With regard to pandemic preparedness, it is important that procedures are in place to respond rapidly and produce tailor made vaccines against these respiratory viruses on short notice. Moreover, especially for influenza there is great need for the development of a universal vaccine that induces broad protective immunity against influenza viruses of various subtypes. Modified Vaccinia Virus Ankara (MVA) is a replication-deficient viral vector that holds great promise as a vaccine platform. MVA can encode one or more foreign antigens and thus functions as a multivalent vaccine. The vector can be used at biosafety level 1, has intrinsic adjuvant capacities and induces humoral and cellular immune responses. However, there are some practical and regulatory issues that need to be addressed in order to develop MVA-based vaccines on short notice at the verge of a pandemic. In this review, we discuss promising novel influenza virus vaccine targets and the use of MVA for vaccine development against various respiratory viruses. PMID:25036462

  10. Modified vaccinia virus ankara (MVA) as production platform for vaccines against influenza and other viral respiratory diseases.

    PubMed

    Altenburg, Arwen F; Kreijtz, Joost H C M; de Vries, Rory D; Song, Fei; Fux, Robert; Rimmelzwaan, Guus F; Sutter, Gerd; Volz, Asisa

    2014-07-01

    Respiratory viruses infections caused by influenza viruses, human parainfluenza virus (hPIV), respiratory syncytial virus (RSV) and coronaviruses are an eminent threat for public health. Currently, there are no licensed vaccines available for hPIV, RSV and coronaviruses, and the available seasonal influenza vaccines have considerable limitations. With regard to pandemic preparedness, it is important that procedures are in place to respond rapidly and produce tailor made vaccines against these respiratory viruses on short notice. Moreover, especially for influenza there is great need for the development of a universal vaccine that induces broad protective immunity against influenza viruses of various subtypes. Modified Vaccinia Virus Ankara (MVA) is a replication-deficient viral vector that holds great promise as a vaccine platform. MVA can encode one or more foreign antigens and thus functions as a multivalent vaccine. The vector can be used at biosafety level 1, has intrinsic adjuvant capacities and induces humoral and cellular immune responses. However, there are some practical and regulatory issues that need to be addressed in order to develop MVA-based vaccines on short notice at the verge of a pandemic. In this review, we discuss promising novel influenza virus vaccine targets and the use of MVA for vaccine development against various respiratory viruses. PMID:25036462

  11. Quantification of Influenza Virus RNA in Aerosols in Patient Rooms

    PubMed Central

    Leung, Nancy H. L.; Zhou, Jie; Chu, Daniel K. W.; Yu, Han; Lindsley, William G.; Beezhold, Donald H.; Yen, Hui-Ling; Li, Yuguo; Seto, Wing-Hong; Peiris, Joseph S. M.; Cowling, Benjamin J.

    2016-01-01

    Background The potential for human influenza viruses to spread through fine particle aerosols remains controversial. The objective of our study was to determine whether influenza viruses could be detected in fine particles in hospital rooms. Methods and Findings We sampled the air in 2-bed patient isolation rooms for four hours, placing cyclone samplers at heights of 1.5m and 1.0m. We collected ten air samples each in the presence of at least one patient with confirmed influenza A virus infection, and tested the samples by reverse transcription polymerase chain reaction. We recovered influenza A virus RNA from 5/10 collections (50%); 4/5 were from particles>4 μm, 1/5 from 1–4 μm, and none in particles<1 μm. Conclusions Detection of influenza virus RNA in aerosols at low concentrations in patient rooms suggests that healthcare workers and visitors might have frequent exposure to airborne influenza virus in proximity to infected patients. A limitation of our study was the small sample size. Further studies should be done to quantify the concentration of viable influenza virus in healthcare settings, and factors affecting the detection of influenza viruses in fine particles in the air. PMID:26849130

  12. Saikosaponin A inhibits influenza A virus replication and lung immunopathology.

    PubMed

    Chen, Jianxin; Duan, Mubing; Zhao, Yaqin; Ling, Fangfang; Xiao, Kun; Li, Qian; Li, Bin; Lu, Chunni; Qi, Wenbao; Zeng, Zhenling; Liao, Ming; Liu, Yahong; Chen, Weisan

    2015-12-15

    Fatal influenza outcomes result from a combination of rapid virus replication and collateral lung tissue damage caused by exaggerated pro-inflammatory host immune cell responses. There are few therapeutic agents that target both biological processes for the attenuation of influenza-induced lung pathology. We show that Saikosaponin A, a bioactive triterpene saponin with previouslyestablished anti-inflammatory effects, demonstrates both in vitro and in vivo anti-viral activity against influenza A virus infections. Saikosaponin A attenuated the replication of three different influenza A virus strains, including a highly pathogenic H5N1 strain, in human alveolar epithelial A549 cells. This anti-viral activity occurred through both downregulation of NF-κB signaling and caspase 3-dependent virus ribonucleoprotein nuclear export as demonstrated by NF-κB subunit p65 and influenza virus nucleoprotein nuclear translocation studies in influenza virus infected A549 cells. Critically, Saikosaponin A also attenuated viral replication, aberrant pro-inflammatory cytokine production and lung histopathology in the widely established H1N1 PR8 model of influenza A virus lethality in C57BL/6 mice. Flow cytometry studies of mouse bronchoalveolar lavage cells revealed that SSa exerted immunomodulatory effects through a selective attenuation of lung neutrophil and monocyte recruitment during the early peak of the innate immune response to PR8 infection. Altogether, our results indicate that Saikosaponin A possesses novel therapeutic potential for the treatment of pathological influenza virus infections. PMID:26637810

  13. Quantifying the global antigenic diversity of swine influenza A viruses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine influenza presents a substantial disease burden for pig populations worldwide and poses a potential pandemic threat to humans. There is considerable diversity in both H1 and H3 influenza viruses circulating in swine due to the frequent introductions of viruses from humans and birds coupled wit...

  14. Experimental Infection of Pigs with the 1918 Pandemic Influenza Virus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Swine influenza was first recognized as a disease during the 1918 "Spanish flu" pandemic suggesting the Spanish flu virus caused swine influenza. The objective of this study was to determine the susceptibility of swine to the Spanish flu virus. A plasmid-derived 1918 pandemic H1N1 (1918/rec) influe...

  15. Sequencing of avian influenza virus genomes following random amplification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian Influenza (AI) is a significant disease of birds and a threat to humans. Recently, as a result of the emergence of Asian H5N1 viruses capable of zoonotic spread, wild and domestic bird surveillance for Avian Influenza viruses (AIV) has increased worldwide, requiring the development of fast a...

  16. Saikosaponin A inhibits influenza A virus replication and lung immunopathology

    PubMed Central

    Zhao, Yaqin; Ling, Fangfang; Xiao, Kun; Li, Qian; Li, Bin; Lu, Chunni; Qi, Wenbao; Zeng, Zhenling; Liao, Ming; Liu, Yahong; Chen, Weisan

    2015-01-01

    Fatal influenza outcomes result from a combination of rapid virus replication and collateral lung tissue damage caused by exaggerated pro-inflammatory host immune cell responses. There are few therapeutic agents that target both biological processes for the attenuation of influenza-induced lung pathology. We show that Saikosaponin A, a bioactive triterpene saponin with previouslyestablished anti-inflammatory effects, demonstrates both in vitro and in vivo anti-viral activity against influenza A virus infections. Saikosaponin A attenuated the replication of three different influenza A virus strains, including a highly pathogenic H5N1 strain, in human alveolar epithelial A549 cells. This anti-viral activity occurred through both downregulation of NF-κB signaling and caspase 3-dependent virus ribonucleoprotein nuclear export as demonstrated by NF-κB subunit p65 and influenza virus nucleoprotein nuclear translocation studies in influenza virus infected A549 cells. Critically, Saikosaponin A also attenuated viral replication, aberrant pro-inflammatory cytokine production and lung histopathology in the widely established H1N1 PR8 model of influenza A virus lethality in C57BL/6 mice. Flow cytometry studies of mouse bronchoalveolar lavage cells revealed that SSa exerted immunomodulatory effects through a selective attenuation of lung neutrophil and monocyte recruitment during the early peak of the innate immune response to PR8 infection. Altogether, our results indicate that Saikosaponin A possesses novel therapeutic potential for the treatment of pathological influenza virus infections. PMID:26637810

  17. Experimental vaccinations for avian influenza virus including DIVA approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) is a viral disease of poultry that remains an economic threat to commercial poultry throughout the world by negatively impacting animal health and trade. Strategies to control avian influenza (AI) virus are developed to prevent, manage or eradicate the virus from the country, re...

  18. Seasonal trivalent inactivated influenza vaccine protects against 1918 Spanish influenza virus in ferrets

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influenza H1N1 pandemic of 1918 was one of the worst medical disasters in human history. Recent studies have demonstrated that the hemagglutinin (HA) protein of the 1918 virus and 2009 H1N1 pandemic virus, the latter now a component of the seasonal trivalent inactivated influenza vaccine (TIV),...

  19. Influenza infection in wild raccoons

    USGS Publications Warehouse

    Hall, J.S.; Bentler, K.T.; Landolt, G.; Elmore, S.A.; Minnis, R.B.; Campbell, T.A.; Barras, S.C.; Root, J.J.; Pilon, J.; Pabilonia, K.; Driscoll, C.; Slate, D.; Sullivan, H.; McLean, R.G.

    2008-01-01

    Raccoons (Procyon lotor) are common, widely distributed animals that frequently come into contact with wild waterfowl, agricultural operations, and humans. Serosurveys showed that raccoons are exposed to avian influenza virus. We found antibodies to a variety of influenza virus subtypes (H10N7, H4N6, H4N2, H3, and H1) with wide geographic variation in seroprevalence. Experimental infection studies showed that raccoons become infected with avian and human influenza A viruses, shed and transmit virus to virus-free animals, and seroconvert. Analyses of cellular receptors showed that raccoons have avian and human type receptors with a similar distribution as found in human respiratory tracts. The potential exists for co-infection of multiple subtypes of influenza virus with genetic reassortment and creation of novel strains of influenza virus. Experimental and field data indicate that raccoons may play an important role in influenza disease ecology and pose risks to agriculture and human health.

  20. Age at vaccination and timing of infection do not alter vaccine-associated enhanced respiratory disease in influenza A virus infected pigs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Whole inactivated virus (WIV) vaccines are widely used in the swine industry to reduce clinical disease against homologous influenza A virus (IAV) infection. In pigs experimentally challenged with antigenically distinct heterologous IAV of the same hemagglutinin subtype, WIV vaccinates have been sho...

  1. Virus-neutralizing antibody response of mice to consecutive infection with human and avian influenzaviruses.

    PubMed

    Janulíková, J; Stropkovská, A; Bobišová, Z; Košík, I; Mucha, V; Kostolanský, F; Varečková, E

    2015-06-01

    In this work we simulated in a mouse model a naturally occurring situation of humans, who overcame an infection with epidemic strains of influenza A, and were subsequently exposed to avian influenzaviruses (IAV). The antibody response to avian IAV in mice previously infected with human IAV was analyzed. We used two avian IAV (A/Duck/Czechoslovakia/1956 (H4N6) and the attenuated virus rA/Viet Nam/1203-2004 (H5N1)) as well as two human IAV isolates (virus A/Mississippi/1/1985 (H3N2) of medium virulence and A/Puerto Rico/8/1934 (H1N1) of high virulence). Two repeated doses of IAV of H4 or of H5 virus elicited virus-specific neutralizing antibodies in mice. Exposure of animals previously infected with human IAV (of H3 or H1 subtype) to IAV of H4 subtype led to the production of antibodies neutralizing H4 virus in a level comparable with the level of antibodies against the human IAV used for primary infection. In contrast, no measurable levels of virus-neutralizing (VN) antibodies specific to H5 virus were detected in mice infected with H5 virus following a previous infection with human IAV. In both cases the secondary infection with avian IAV led to a significant increase of the titer of VN antibodies specific to the corresponding human virus used for primary infection. Moreover, cross-reactive HA2-specific antibodies were also induced by sequential infection. By virtue of these results we suggest that the differences in the ability of avian IAV to induce specific antibodies inhibiting virus replication after previous infection of mice with human viruses can have an impact on the interspecies transmission and spread of avian IAV in the human population. PMID:26104333

  2. Development of high-yield influenza A virus vaccine viruses.

    PubMed

    Ping, Jihui; Lopes, Tiago J S; Nidom, Chairul A; Ghedin, Elodie; Macken, Catherine A; Fitch, Adam; Imai, Masaki; Maher, Eileen A; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for use in humans, but their yields are often suboptimal. Here, we screened A/Puerto Rico/8/34 (PR8) virus mutant libraries to develop vaccine backbones (defined here as the six viral RNA segments not encoding haemagglutinin and neuraminidase) that support high yield in cell culture. We also tested mutations in the coding and regulatory regions of the virus, and chimeric haemagglutinin and neuraminidase genes. A combination of high-yield mutations from these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin-Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in seasonal and pandemic influenza vaccine development. PMID:26334134

  3. Development of high-yield influenza A virus vaccine viruses

    PubMed Central

    Ping, Jihui; Lopes, Tiago J.S.; Nidom, Chairul A.; Ghedin, Elodie; Macken, Catherine A.; Fitch, Adam; Imai, Masaki; Maher, Eileen A.; Neumann, Gabriele; Kawaoka, Yoshihiro

    2015-01-01

    Vaccination is one of the most cost-effective ways to prevent infection. Influenza vaccines propagated in cultured cells are approved for use in humans, but their yields are often suboptimal. Here, we screened A/Puerto Rico/8/34 (PR8) virus mutant libraries to develop vaccine backbones (defined here as the six viral RNA segments not encoding haemagglutinin and neuraminidase) that support high yield in cell culture. We also tested mutations in the coding and regulatory regions of the virus, and chimeric haemagglutinin and neuraminidase genes. A combination of high-yield mutations from these screens led to a PR8 backbone that improved the titres of H1N1, H3N2, H5N1 and H7N9 vaccine viruses in African green monkey kidney and Madin–Darby canine kidney cells. This PR8 backbone also improves titres in embryonated chicken eggs, a common propagation system for influenza viruses. This PR8 vaccine backbone thus represents an advance in seasonal and pandemic influenza vaccine development. PMID:26334134

  4. The contrasting phylodynamics of human influenza B viruses.

    PubMed

    Vijaykrishna, Dhanasekaran; Holmes, Edward C; Joseph, Udayan; Fourment, Mathieu; Su, Yvonne C F; Halpin, Rebecca; Lee, Raphael T C; Deng, Yi-Mo; Gunalan, Vithiagaran; Lin, Xudong; Stockwell, Timothy B; Fedorova, Nadia B; Zhou, Bin; Spirason, Natalie; Kühnert, Denise; Bošková, Veronika; Stadler, Tanja; Costa, Anna-Maria; Dwyer, Dominic E; Huang, Q Sue; Jennings, Lance C; Rawlinson, William; Sullivan, Sheena G; Hurt, Aeron C; Maurer-Stroh, Sebastian; Wentworth, David E; Smith, Gavin J D; Barr, Ian G

    2015-01-01

    A complex interplay of viral, host, and ecological factors shapes the spatio-temporal incidence and evolution of human influenza viruses. Although considerable attention has been paid to influenza A viruses, a lack of equivalent data means that an integrated evolutionary and epidemiological framework has until now not been available for influenza B viruses, despite their significant disease burden. Through the analysis of over 900 full genomes from an epidemiological collection of more than 26,000 strains from Australia and New Zealand, we reveal fundamental differences in the phylodynamics of the two co-circulating lineages of influenza B virus (Victoria and Yamagata), showing that their individual dynamics are determined by a complex relationship between virus transmission, age of infection, and receptor binding preference. In sum, this work identifies new factors that are important determinants of influenza B evolution and epidemiology. PMID:25594904

  5. The contrasting phylodynamics of human influenza B viruses

    PubMed Central

    Vijaykrishna, Dhanasekaran; Holmes, Edward C; Joseph, Udayan; Fourment, Mathieu; Su, Yvonne CF; Halpin, Rebecca; Lee, Raphael TC; Deng, Yi-Mo; Gunalan, Vithiagaran; Lin, Xudong; Stockwell, Timothy B; Fedorova, Nadia B; Zhou, Bin; Spirason, Natalie; Kühnert, Denise; Bošková, Veronika; Stadler, Tanja; Costa, Anna-Maria; Dwyer, Dominic E; Huang, Q Sue; Jennings, Lance C; Rawlinson, William; Sullivan, Sheena G; Hurt, Aeron C; Maurer-Stroh, Sebastian; Wentworth, David E; Smith, Gavin JD; Barr, Ian G

    2015-01-01

    A complex interplay of viral, host, and ecological factors shapes the spatio-temporal incidence and evolution of human influenza viruses. Although considerable attention has been paid to influenza A viruses, a lack of equivalent data means that an integrated evolutionary and epidemiological framework has until now not been available for influenza B viruses, despite their significant disease burden. Through the analysis of over 900 full genomes from an epidemiological collection of more than 26,000 strains from Australia and New Zealand, we reveal fundamental differences in the phylodynamics of the two co-circulating lineages of influenza B virus (Victoria and Yamagata), showing that their individual dynamics are determined by a complex relationship between virus transmission, age of infection, and receptor binding preference. In sum, this work identifies new factors that are important determinants of influenza B evolution and epidemiology. DOI: http://dx.doi.org/10.7554/eLife.05055.001 PMID:25594904

  6. The Breadth of Cross Sub-Type Neutralisation Activity of a Single Domain Antibody to Influenza Hemagglutinin Can Be Increased by Antibody Valency

    PubMed Central

    Hufton, Simon E.; Risley, Paul; Ball, Christina R.; Major, Diane; Engelhardt, Othmar G.; Poole, Stephen

    2014-01-01

    The response to the 2009 A(H1N1) influenza pandemic has highlighted the need for additional strategies for intervention which preclude the prior availability of the influenza strain. Here, 18 single domain VHH antibodies against the 2009 A(H1N1) hemagglutinin (HA) have been isolated from a immune alpaca phage displayed library. These antibodies have been grouped as having either (i) non-neutralising, (ii) H1N1 restricted neutralising or (iii) broad cross-subtype neutralising activity. The ability to neutralise different viral subtypes, including highly pathogenic avian influenza (H5N1), correlated with the absence of hemagglutination inhibition activity, loss of binding to HA at acid pH and the absence of binding to the head domain containing the receptor binding site. This data supports their binding to epitopes in the HA stem region and a mechanism of action other than blocking viral attachment to cell surface receptors. After conversion of cross-neutralising antibodies R1a-B6 and R1a-A5 into a bivalent format, no significant enhancement in neutralisation activity was seen against A(H1N1) and A(H5N1) viruses. However, bivalent R1a-B6 showed an 18 fold enhancement in potency against A(H9N2) virus and, surprisingly, gained the ability to neutralise an A(H2N2) virus. This demonstrates that cross-neutralising antibodies, which make lower affinity interactions with the membrane proximal stem region of more divergent HA sub-types, can be optimised by bivalency so increasing their breadth of anti-viral activity. The broad neutralising activity and favourable characteristics, such as high stability, simple engineering into bivalent molecules and low cost production make these single domain antibodies attractive candidates for diagnostics and immunotherapy of pandemic influenza. PMID:25084445

  7. [Influenza virus epidemiology and ecology, with special reference to bird species associated with water. Literature review and observations].

    PubMed

    van Tongeren, H A; Voous, K H

    1987-12-01

    Only a limited number of A-subtypes of influenza virus so far caused disease in human subjects, pigs and horses; this occurred in more or less defined areas which occasionally showed epidemic aggravations, becoming apparent as rapidly spreading epidemics or otherwise in even the form of pandemics. However this number of antigenic subtypes was found to be fairly constant and host-specific. Earlier studies were done in domesticated fowl and birds, though particularly in water birds in recent years, and numerous subtypes were detected, only a small number of these subtypes also being found to occur in man, pigs and horses. It became increasingly apparent that particularly mallards, but also other water birds play an extremely important role in the maintenance as well as in the distribution and circulation of these orthomyxoviruses in nature. These infections in water birds were not merely caused by a single subtype but occasionally by two or more antigenically different subtypes. This could be conducive to the appearance of recombinants as a result of genetic rearrangement in the cells lining the alimentary tracts of birds. Occasionally, subtypes observed in man were also found to occur in birds, which gave rise to the question of the extent to which birds are the origin or sources of infections of human epidemics caused by these subtypes. This also holds good for the subtypes in pigs. In addition to a number of oecological and ornithological considerations, reference was also made to systematic facts and routes along which further investigations on the presence of influenza viruses in the world of birds could be taken up, particular attention being paid to migratory birds. As birds of passage pass over and find their way into isolated areas as well as human population centres, these birds play a role which is yet unknown both in the distribution and in the overwintering of influenza viruses. Conditions in which wild and domesticated (water) birds, pigs, horses and

  8. Efficacy of the New Neuraminidase Inhibitor CS-8958 against H5N1 Influenza Viruses

    PubMed Central

    Kiso, Maki; Kubo, Shuku; Ozawa, Makoto; Le, Quynh Mai; Nidom, Chairul A.; Yamashita, Makoto; Kawaoka, Yoshihiro

    2010-01-01

    Currently, two neuraminidase (NA) inhibitors, oseltamivir and zanamivir, which must be administrated twice daily for 5 days for maximum therapeutic effect, are licensed for the treatment of influenza. However, oseltamivir-resistant mutants of seasonal H1N1 and highly pathogenic H5N1 avian influenza A viruses have emerged. Therefore, alternative antiviral agents are needed. Recently, a new neuraminidase inhibitor, R-125489, and its prodrug, CS-8958, have been developed. CS-8958 functions as a long-acting NA inhibitor in vivo (mice) and is efficacious against seasonal influenza strains following a single intranasal dose. Here, we tested the efficacy of this compound against H5N1 influenza viruses, which have spread across several continents and caused epidemics with high morbidity and mortality. We demonstrated that R-125489 interferes with the NA activity of H5N1 viruses, including oseltamivir-resistant and different clade strains. A single dose of CS-8958 (1,500 µg/kg) given to mice 2 h post-infection with H5N1 influenza viruses produced a higher survival rate than did continuous five-day administration of oseltamivir (50 mg/kg twice daily). Virus titers in lungs and brain were substantially lower in infected mice treated with a single dose of CS-8958 than in those treated with the five-day course of oseltamivir. CS-8958 was also highly efficacious against highly pathogenic H5N1 influenza virus and oseltamivir-resistant variants. A single dose of CS-8958 given seven days prior to virus infection also protected mice against H5N1 virus lethal infection. To evaluate the improved efficacy of CS-8958 over oseltamivir, the binding stability of R-125489 to various subtypes of influenza virus was assessed and compared with that of other NA inhibitors. We found that R-125489 bound to NA more tightly than did any other NA inhibitor tested. Our results indicate that CS-8958 is highly effective for the treatment and prophylaxis of infection with H5N1 influenza viruses

  9. Research update on avian influenza viruses and H1N1 influenza virus in poultry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Avian influenza (AI) remains an economic threat to commercial poultry throughout the world by negatively impacting animal health and trade. Southeast Poultry Research Laboratory conducts research on many areas related to AI including pathogenesis and transmission studies, use of vaccination, virus ...

  10. Development and clinical testing of a simple, low-density gel element array for influenza identification, subtyping, and H275Y detection.

    PubMed

    Chandler, Darrell P; Griesemer, Sara B; Knickerbocker, Christopher; Golova, Julia B; Lambarqui, Amine; Perov, Alexander N; Zimmerman, Cynthia; Wiles, Cory; Rudy, George B; St George, Kirsten

    2014-11-01

    The objectives of this study were to develop a user-friendly, gel element microarray test for influenza virus detection, subtyping, and neuraminidase inhibitor resistance detection, assess the performance characteristics of the assay, and perform a clinical evaluation on retrospective nasopharyngeal swab specimens. A streamlined microarray workflow enabled a single user to run up to 24 tests in an 8h shift. The most sensitive components of the test were the primers and probes targeting the A/H1 pdm09 HA gene with an analytical limit of detection (LoD) <100 gene copies (gc) per reaction. LoDs for all targets in nasopharyngeal swab samples were ≤1000 gc, with the exception of one target in the seasonal A/H1N1 subtype. Seasonal H275Y variants were detectable in a mixed population when present at >5% with wild type virus, while the 2009 pandemic H1N1 H275Y variant was detectable at ≤1% in a mixture with pandemic wild type virus. Influenza typing and subtyping results concurred with those obtained with real-time RT-PCR assays on more than 97% of the samples tested. The results demonstrate that a large panel of single-plex, real-time RT-PCR tests can be translated to an easy-to-use, sensitive, and specific microarray test for potential diagnostic use. PMID:25066276

  11. A survey of Mycoplasma gallisepticum and Mycoplasma synovaie with avian influenza H9 subtype in meat-type chicken in Jordan between 2011-2015.

    PubMed

    Roussan, Dergham Ahmad; Khawaldeh, Ghassan; Shaheen, Ibrahim Ali

    2015-07-01

    Commercial chickens in Jordan suffer from respiratory disease of undetermined etiology. This study was designed to document the involvement of avian influenza virus (AIV) H9 subtype, Mycoplasma gallisepticum (MG), and Mycoplasma synoviae (MS) in this respiratory disease. In this study, trachea swabs from 350 commercial broiler chicken flocks that suffered from respiratory disease were tested for AIV H9 subtype by using reverse transcription (RT)-PCR and for MG and MS by using PCR. PCR and RT-PCR results showed that 23.7, 8.9, and 6.6% of these flocks were infected with AIV H9 subtype, MS, and MG, respectively, whereas 12.9 and 5.7% of these flocks were infected with both AIV H9 subtype and MS and AIV H9 subtype and MS, respectively. Furthermore, 42.3% of these flocks were negative for the above mentioned respiratory diseases. Further epidemiological studies are recommended to determine risk factors and evaluate the economic consequences of AIV H9 subtype, MG, and MS infections in the region. Furthermore, studies are required to isolate AIV H9 subtype, MG, and MS and develop vaccines against the local field isolates. PMID:25971950

  12. Glycan-receptor specificity as a useful tool for characterization and surveillance of influenza A virus

    PubMed Central

    Raman, Rahul; Tharakaraman, Kannan; Shriver, Zachary; Jayaraman, Akila; Sasisekharan, V.; Sasisekharan, Ram

    2014-01-01

    Influenza A viruses are rapidly evolving pathogens with the potential for novel strains to emerge and result in pandemic outbreaks in humans. Some avian-adapted subtypes have acquired the ability to bind to human glycan receptors and cause severe infections in humans but have yet to adapt to and transmit between humans. The emergence of new avian strains and their ability to infect humans has confounded their distinction from circulating human virus strains through linking receptor specificity to human adaptation. Herein we review the various structural and biochemical analyses of influenza hemagglutinin–glycan receptor interactions. We provide our perspectives on how receptor specificity can be used to monitor evolution of the virus to adapt to human hosts so as to facilitate improved surveillance and pandemic preparedness. PMID:25108746

  13. Diffusion of Influenza Viruses among Migratory Birds with a Focus on the Southwest United States

    PubMed Central

    Scotch, Matthew; Lam, Tommy Tsan-Yuk; Pabilonia, Kristy L.; Anderson, Theodore; Baroch, John; Kohler, Dennis; DeLiberto, Thomas J.

    2014-01-01

    The Southwest United States, including Arizona and New Mexico, has a diverse climate and is home to many different avian species. We sequenced the hemagglutinin (HA) gene of twenty influenza specimens for the years 2007–2009. This included four from Arizona, and sixteen from New Mexico. We analyzed the sequences and determined the following HA subtypes: H3, H4, H6, H8, and H11. For each subtype, we combined our virus sequences with those from a public database, and inferred phylogeographic models of influenza diffusion. Statistical phylogeography indicated that overall evolutionary diffusion of avian influenza viruses is geographically structured (p < 0.05). In addition, we found that diffusion to the Southwest was often from nearby states including California. For H3, H4 and H6, the intra-flyway gene flow rates were significantly (p < 0.001) higher than those of inter-flyway. Such rate difference was also observed in H8 and H11, yet, without statistical significance (p=0.132, p=0.190 respectively). Excluding any one flyway from the calculation generated similar results, suggesting that such barrier effect on gene flow rates is not exclusively produced by any single flyway. We also calculated the Bayes factor test for the significant non-zero rates between states and identified significant routes both within and across flyways. Such inter-flyway spread of influenza was probably the result of birds from four flyways co-mingling on breeding grounds in northern regions or marshaling on staging areas post breeding in Canada or Alaska, before moving south each fall. This study provides an initial analysis of evolutionary diffusion of avian influenza virus to and from the Southwest United States. However, more sequences from this region need to be generated to determine the role of host migration and other factors on influenza diffusion. PMID:24910106

  14. Differential Sensitivity of Bat Cells to Infection by Enveloped RNA Viruses: Coronaviruses, Paramyxoviruses, Filoviruses, and Influenza Viruses

    PubMed Central

    Hoffmann, Markus; Müller, Marcel Alexander; Drexler, Jan Felix; Glende, Jörg; Erdt, Meike; Gützkow, Tim; Losemann, Christoph; Binger, Tabea; Deng, Hongkui; Schwegmann-Weßels, Christel; Esser, Karl-Heinz; Drosten, Christian; Herrler, Georg

    2013-01-01

    Bats (Chiroptera) host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat) or Yangochiroptera (genera Carollia and Tadarida) for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV), a porcine coronavirus, or to infection mediated by the Spike (S) protein of SARS-coronavirus (SARS-CoV) incorporated into pseudotypes based on vesicular stomatitis virus (VSV). The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3) were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus) and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed. PMID:24023659

  15. Differential sensitivity of bat cells to infection by enveloped RNA viruses: coronaviruses, paramyxoviruses, filoviruses, and influenza viruses.

    PubMed

    Hoffmann, Markus; Müller, Marcel Alexander; Drexler, Jan Felix; Glende, Jörg; Erdt, Meike; Gützkow, Tim; Losemann, Christoph; Binger, Tabea; Deng, Hongkui; Schwegmann-Weßels, Christel; Esser, Karl-Heinz; Drosten, Christian; Herrler, Georg

    2013-01-01

    Bats (Chiroptera) host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat) or Yangochiroptera (genera Carollia and Tadarida) for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV), a porcine coronavirus, or to infection mediated by the Spike (S) protein of SARS-coronavirus (SARS-CoV) incorporated into pseudotypes based on vesicular stomatitis virus (VSV). The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3) were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus) and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed. PMID:24023659

  16. Heterosubtypic antibody recognition of the influenza virus hemagglutinin receptor binding site enhanced by avidity

    PubMed Central

    Lee, Peter S.; Yoshida, Reiko; Ekiert, Damian C.; Sakai, Naoki; Suzuki, Yasuhiko; Takada, Ayato; Wilson, Ian A.

    2012-01-01

    Continual and rapid mutation of seasonal influenza viruses by antigenic drift necessitates the almost annual reformulation of flu vaccines, which may offer little protection if the match to the dominant circulating strain is poor. S139/1 is a cross-reactive antibody that neutralizes multiple HA strains and subtypes, including those from H1N1 and H3N2 viruses that currently infect humans. The crystal structure of the S139/1 Fab in complex with the HA from the A/Victoria/3/1975 (H3N2) virus reveals that the antibody targets highly conserved residues in the receptor binding site and contacts antigenic sites A, B, and D. Binding and plaque reduction assays show that the monovalent Fab alone can protect against H3 strains, but the enhanced avidity from binding of bivalent IgG increases the breadth of neutralization to additional strains from the H1, H2, H13, and H16 subtypes. Thus, antibodies making relatively low affinity Fab interactions with the receptor binding site can have significant antiviral activity when enhanced by avidity through bivalent interactions of the IgG, thereby extending the breadth of binding and neutralization to highly divergent influenza virus strains and subtypes. PMID:23027945

  17. The Mutational Robustness of Influenza A Virus.

    PubMed

    Visher, Elisa; Whitefield, Shawn E; McCrone, John T; Fitzsimmons, William; Lauring, Adam S

    2016-08-01

    A virus' mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16) than in the other 6 segments (0.78 ± 0.24), and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects. PMID:27571422

  18. Protection from Severe Influenza Virus Infections in Mice Carrying the Mx1 Influenza Virus Resistance Gene Strongly Depends on Genetic Background

    PubMed Central

    Shin, Dai-Lun; Hatesuer, Bastian; Bergmann, Silke; Nedelko, Tatiana

    2015-01-01

    ABSTRACT Influenza virus infections represent a serious threat to human health. Both extrinsic and intrinsic factors determine the severity of influenza. The MX dynamin-like GTPase 1 (Mx1) gene has been shown to confer strong resistance to influenza A virus infections in mice. Most laboratory mouse strains, including C57BL/6J, carry nonsense or deletion mutations in Mx1 and thus a nonfunctional allele, whereas wild-derived mouse strains carry a wild-type Mx1 allele. Congenic C57BL/6J (B6-Mx1r/r) mice expressing a wild-type allele from the A2G mouse strain are highly resistant to influenza A virus infections, to both mono- and polybasic subtypes. Furthermore, in genetic mapping studies, Mx1 was identified as the major locus of resistance to influenza virus infections. Here, we investigated whether the Mx1 protective function is influenced by the genetic background. For this, we generated a congenic mouse strain carrying the A2G wild-type Mx1 resistance allele on a DBA/2J background (D2-Mx1r/r). Most remarkably, congenic D2-Mx1r/r mice expressing a functional Mx1 wild-type allele are still highly susceptible to H1N1 virus. However, pretreatment of D2-Mx1r/r mice with alpha interferon protected them from lethal infections. Our results showed, for the first time, that the presence of an Mx1 wild-type allele from A2G as such does not fully protect mice from lethal influenza A virus infections. These observations are also highly relevant for susceptibility to influenza virus infections in humans. IMPORTANCE Influenza A virus represents a major health threat to humans. Seasonal influenza epidemics cause high economic loss, morbidity, and deaths each year. Genetic factors of the host strongly influence susceptibility and resistance to virus infections. The Mx1 (MX dynamin-like GTPase 1) gene has been described as a major resistance gene in mice and humans. Most inbred laboratory mouse strains are deficient in Mx1, but congenic B6-Mx1r/r mice that carry the wild-type Mx1

  19. Inhibitors of influenza viruses replication: a patent evaluation (WO2013019828).

    PubMed

    Xie, Yuanchao; Song, Weiguo; Xiao, Weidong; Gu, Changjuan; Xu, Wenfang

    2013-11-01

    A series of compounds incorporating two aromatic heterocycles were prepared as inhibitors of influenza virus replication in the patent. Some of them presented potent activity against influenza virus in Madin-Darby canine kidney (MDCK) cells and in influenza therapeutic mouse model. These compounds in the patent were also defined to be pharmaceutically acceptable salts and pharmaceutical compositions that were claimed to be useful for treating influenza. In view of the threat of influenza pandemic, it is necessary to discover new anti-influenza drugs. Although there is a lack of essential biological data and the molecular mechanisms are not clear, these compounds with potent antiviral activity stand for a new type of anti-influenza agents and deserve further studies. PMID:23967861

  20. African Green Monkeys Recapitulate the Clinical Experience with Replication of Live Attenuated Pandemic Influenza Virus Vaccine Candidates

    PubMed Central

    Matsuoka, Yumiko; Suguitan, Amorsolo; Orandle, Marlene; Paskel, Myeisha; Boonnak, Kobporn; Gardner, Donald J.; Feldmann, Friederike; Feldmann, Heinz; Marino, Michael; Jin, Hong; Kemble, George

    2014-01-01

    ABSTRACT Live attenuated cold-adapted (ca) H5N1, H7N3, H6N1, and H9N2 influenza vaccine viruses replicated in the respiratory tract of mice and ferrets, and 2 doses of vaccines were immunogenic and protected these animals from challenge infection with homologous and heterologous wild-type (wt) viruses of the corresponding subtypes. However, when these vaccine candidates were evaluated in phase I clinical trials, there were inconsistencies between the observations in animal models and in humans. The vaccine viruses did not replicate well and immune responses were variable in humans, even though the study subjects were seronegative with respect to the vaccine viruses before vaccination. Therefore, we sought a model that would better reflect the findings in humans and evaluated African green monkeys (AGMs) as a nonhuman primate model. The distribution of sialic acid (SA) receptors in the respiratory tract of AGMs was similar to that in humans. We evaluated the replication of wt and ca viruses of avian influenza (AI) virus subtypes H5N1, H6N1, H7N3, and H9N2 in the respiratory tract of AGMs. All of the wt viruses replicated efficiently, while replication of the ca vaccine viruses was restricted to the upper respiratory tract. Interestingly, the patterns and sites of virus replication differed among the different subtypes. We also evaluated the immunogenicity and protective efficacy of H5N1, H6N1, H7N3, and H9N2 ca vaccines. Protection from wt virus challenge correlated well with the level of serum neutralizing antibodies. Immune responses were slightly better when vaccine was delivered by both intranasal and intratracheal delivery than when it was delivered intranasally by sprayer. We conclude that live attenuated pandemic influenza virus vaccines replicate similarly in AGMs and human subjects and that AGMs may be a useful model to evaluate the replication of ca vaccine candidates. IMPORTANCE Ferrets and mice are commonly used for preclinical evaluation of influenza

  1. Sialic acid tissue distribution and influenza virus tropism

    PubMed Central

    Kumlin, Urban; Olofsson, Sigvard; Dimock, Ken; Arnberg, Niklas

    2008-01-01

    Abstract  Avian influenza A viruses exhibit a strong preference for using α2,3‐linked sialic acid as a receptor. Until recently, the presumed lack of this receptor in human airways was believed to constitute an efficient barrier to avian influenza A virus infection of humans. Recent zoonotic outbreaks of avian influenza A virus have triggered researchers to analyse tissue distribution of sialic acid in further detail. Here, we review and extend the current knowledge about sialic acid distribution in human tissues, and discuss viruses with ocular tropism and their preference for α2,3‐linked sialic acid. PMID:19453419

  2. Modeling Influenza Virus Infection: A Roadmap for Influenza Research

    PubMed Central

    Boianelli, Alessandro; Nguyen, Van Kinh; Ebensen, Thomas; Schulze, Kai; Wilk, Esther; Sharma, Niharika; Stegemann-Koniszewski, Sabine; Bruder, Dunja; Toapanta, Franklin R.; Guzmán, Carlos A.; Meyer-Hermann, Michael; Hernandez-Vargas, Esteban A.

    2015-01-01

    Influenza A virus (IAV) infection represents a global threat causing seasonal outbreaks and pandemics. Additionally, secondary bacterial infections, caused mainly by Streptococcus pneumoniae, are one of the main complications and responsible for the enhanced morbidity and mortality associated with IAV infections. In spite of the significant advances in our knowledge of IAV infections, holistic comprehension of the interplay between IAV and the host immune response (IR) remains largely fragmented. During the last decade, mathematical modeling has been instrumental to explain and quantify IAV dynamics. In this paper, we review not only the state of the art of mathematical models of IAV infection but also the methodologies exploited for parameter estimation. We focus on the adaptive IR control of IAV infection and the possible mechanisms that could promote a secondary bacterial coinfection. To exemplify IAV dynamics and identifiability issues, a mathematical model to explain the interactions between adaptive IR and IAV infection is considered. Furthermore, in this paper we propose a roadmap for future influenza research. The development of a mathematical modeling framework with a secondary bacterial coinfection, immunosenescence, host genetic factors and responsiveness to vaccination will be pivotal to advance IAV infection understanding and treatment optimization. PMID:26473911

  3. Current Approaches for Diagnosis of Influenza Virus Infections in Humans.

    PubMed

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-04-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000-50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  4. Current Approaches for Diagnosis of Influenza Virus Infections in Humans

    PubMed Central

    Vemula, Sai Vikram; Zhao, Jiangqin; Liu, Jikun; Wang, Xue; Biswas, Santanu; Hewlett, Indira

    2016-01-01

    Despite significant advancement in vaccine and virus research, influenza continues to be a major public health concern. Each year in the United States of America, influenza viruses are responsible for seasonal epidemics resulting in over 200,000 hospitalizations and 30,000–50,000 deaths. Accurate and early diagnosis of influenza viral infections are critical for rapid initiation of antiviral therapy to reduce influenza related morbidity and mortality both during seasonal epidemics and pandemics. Several different approaches are currently available for diagnosis of influenza infections in humans. These include viral isolation in cell culture, immunofluorescence assays, nucleic acid amplification tests, immunochromatography-based rapid diagnostic tests, etc. Newer diagnostic approaches are being developed to overcome the limitations associated with some of the conventional detection methods. This review discusses diagnostic approaches currently available for detection of influenza viruses in humans. PMID:27077877

  5. Triplet entropy analysis of hemagglutinin and neuraminidase sequences measures influenza virus phylodynamics.

    PubMed

    Gerhardt, Günther J L; Takeda, Agnes A S; Andrighetti, Tahila; Sartor, Ivaine T S; Echeverrigaray, Sergio L; de Avila E Silva, Scheila; Dos Santos, Laurita; Rybarczyk-Filho, José L

    2013-10-10

    The influenza virus has been a challenge to science due to its ability to withstand new environmental conditions. Taking into account the development of virus sequence databases, computational approaches can be helpful to understand virus behavior over time. Furthermore, they can suggest new directions to deal with influenza. This work presents triplet entropy analysis as a potential phylodynamic tool to quantify nucleotide organization of viral sequences. The application of this measure to segments of hemagglutinin (HA) and neuraminidase (NA) of H1N1 and H3N2 virus subtypes has shown some variability effects along timeline, inferring about virus evolution. Sequences were divided by year and compared for virus subtype (H1N1 and H3N2). The nonparametric Mann-Whitney test was used for comparison between groups. Results show that differentiation in entropy precedes differentiation in GC content for both groups. Considering the HA fragment, both triplet entropy as well as GC concentration show intersection in 2009, year of the recent pandemic. Some conclusions about possible flu evolutionary lines were drawn. PMID:23850726

  6. Reassortment of Avian Influenza A/H6N6 Viruses from Live Poultry Markets in Guangdong, China.

    PubMed

    Yuan, Runyu; Zou, Lirong; Kang, Yinfeng; Wu, Jie; Zeng, Xianqiao; Lu, Jing; Liang, Lijun; Song, Yingchao; Zhang, Xin; Ni, Hanzhong; Lin, Jinyan; Liao, Ming; Ke, Changwen

    2016-01-01

    Since early 2013, H7N9-subtype avian influenza virus (AIV) has caused human infection in eastern China. To evaluate AIV contamination and the public risk of infection, we systematically implemented environmental sampling from live poultry markets in Guangdong Province. Through real-time polymerase chain reaction assays and next-generation sequencing, we generated full nucleotide sequences of all 10 H6N6 AIVs isolated during sampling. Focusing on sequence analyses of hemagglutinin genes of the 10 H6N6 AIVs revealed that the viruses were low pathogenic AIVs with the typical hemagglutinin cleavage site of P-Q-I-E-T-R-G. The hemagglutinin, neuraminidase, and nucleocapsid genes of nine AIVs were of ST2853-like (H6-subtype) lineage, ST192-like (N6-subtype) lineage, and HN573-like (H6-subtype) lineage, respectively; whereas the other five genes were of ST339-like (H6-subtype) lineage. However, the polymerase PB2 and nucleocapsid genes of one strain (HZ057) were of GS/GD-like (H5N1-subtype) and ST339-like lineages. Phylogenic analysis revealed that all eight genes of the 10 viruses belonged to Eurasian avian lineage. Altogether, the 10 AIVs were reassortants of different genetic groups of exchanges with the same virus subtype, thus illustrating the genetic diversity and complexity of H6N6-subtype AIVs in Guangdong Province. PMID:26903958

  7. Reassortment of Avian Influenza A/H6N6 Viruses from Live Poultry Markets in Guangdong, China

    PubMed Central

    Yuan, Runyu; Zou, Lirong; Kang, Yinfeng; Wu, Jie; Zeng, Xianqiao; Lu, Jing; Liang, Lijun; Song, Yingchao; Zhang, Xin; Ni, Hanzhong; Lin, Jinyan; Liao, Ming; Ke, Changwen

    2016-01-01

    Since early 2013, H7N9-subtype avian influenza virus (AIV) has caused human infection in eastern China. To evaluate AIV contamination and the public risk of infection, we systematically implemented environmental sampling from live poultry markets in Guangdong Province. Through real-time polymerase chain reaction assays and next-generation sequencing, we generated full nucleotide sequences of all 10 H6N6 AIVs isolated during sampling. Focusing on sequence analyses of hemagglutinin genes of the 10 H6N6 AIVs revealed that the viruses were low pathogenic AIVs with the typical hemagglutinin cleavage site of P-Q-I-E-T-R-G. The hemagglutinin, neuraminidase, and nucleocapsid genes of nine AIVs were of ST2853-like (H6-subtype) lineage, ST192-like (N6-subtype) lineage, and HN573-like (H6-subtype) lineage, respectively; whereas the other five genes were of ST339-like (H6-subtype) lineage. However, the polymerase PB2 and nucleocapsid genes of one strain (HZ057) were of GS/GD-like (H5N1-subtype) and ST339-like lineages. Phylogenic analysis revealed that all eight genes of the 10 viruses belonged to Eurasian avian lineage. Altogether, the 10 AIVs were reassortants of different genetic groups of exchanges with the same virus subtype, thus illustrating the genetic diversity and complexity of H6N6-subtype AIVs in Guangdong Province. PMID:26903958

  8. Cross-protection against European swine influenza viruses in the context of infection immunity against the 2009 pandemic H1N1 virus: studies in the pig model of influenza.

    PubMed

    Qiu, Yu; De Hert, Karl; Van Reeth, Kristien

    2015-01-01

    Pigs are natural hosts for the same influenza virus subtypes as humans and are a valuable model for cross-protection studies with influenza. In this study, we have used the pig model to examine the extent of virological protection between a) the 2009 pandemic H1N1 (pH1N1) virus and three different European H1 swine influenza virus (SIV) lineages, and b) these H1 viruses and a European H3N2 SIV. Pigs were inoculated intranasally with representative strains of each virus lineage with 6- and 17-week intervals between H1 inoculations and between H1 and H3 inoculations, respectively. Virus titers in nasal swabs and/or tissues of the respiratory tract were determined after each inoculation. There was substantial though differing cross-protection between pH1N1 and other H1 viruses, which was directly correlated with the relatedness in the viral hemagglutinin (HA) and neuraminidase (NA) proteins. Cross-protection against H3N2 was almost complete in pigs with immunity against H1N2, but was weak in H1N1/pH1N1-immune pigs. In conclusion, infection with a live, wild type influenza virus may offer substantial cross-lineage protection against viruses of the same HA and/or NA subtype. True heterosubtypic protection, in contrast, appears to be minimal in natural influenza virus hosts. We discuss our findings in the light of the zoonotic and pandemic risks of SIVs. PMID:26404790

  9. Avian influenza in shorebirds: experimental infection of ruddy turnstones (Arenaria interpres) with avian influenza virus

    USGS Publications Warehouse

    Hall, Jeffrey S.; Krauss, Scott; Franson, J. Christian; TeSlaa, Joshua L.; Nashold, Sean W.; Stallknecht, David E.; Webby, Richard J.; Webster, Robert G.

    2013-01-01

    Background: Low pathogenic avian influenza viruses (LPAIV) have been reported in shorebirds, especially at Delaware Bay, USA, during spring migration. However, data on patterns of virus excretion, minimal infectious doses, and clinical outcome are lacking. The ruddy turnstone (Arenaria interpres) is the shorebird species with the highest prevalence of influenza virus at Delaware Bay. Objectives: The primary objective of this study was to experimentally assess the patterns of influenza virus excretion, minimal infectious doses, and clinical outcome in ruddy turnstones. Methods: We experimentally challenged ruddy turnstones using a common LPAIV shorebird isolate, an LPAIV waterfowl isolate, or a highly pathogenic H5N1 avian influenza virus. Cloacal and oral swabs and sera were analyzed from each bird. Results: Most ruddy turnstones had pre-existing antibodies to avian influenza virus, and many were infected at the time of capture. The infectious doses for each challenge virus were similar (103·6–104·16 EID50), regardless of exposure history. All infected birds excreted similar amounts of virus and showed no clinical signs of disease or mortality. Influenza A-specific antibodies remained detectable for at least 2 months after inoculation. Conclusions: These results provide a reference for interpretation of surveillance data, modeling, and predicting the risks of avian influenza transmission and movement in these important hosts.

  10. Keeping the memory of influenza viruses.

    PubMed

    Combadière, B; Sibéril, S; Duffy, D

    2010-04-01

    Protection against pathogens is mediated by both humoral responses (neutralizing antibodies) and cellular immunity, both CD4+ and CD8+ cells. In the case of influenza viruses, circulating strains contain both variable and conserved T and B cell epitopes that are challenged after vaccination and/or infection. During infection, the role of T cells is to prevent viral dissemination in the organism by killing the infected cells and helping B cell antibody production to neutralize the virus. The threat of influenza virus increases the preparedness of protective immunity to pandemic and seasonal infection by vaccination. Several questions remain that need to be further addressed for the future development of innovative and rapidly efficient vaccines strategies. Firstly, what are the correlates of long-term protection (antibodies and/or T cells) against variant strains of influenza? How does the individual factors (age, natural immunity, vaccination and/or infection history) influence the generation and maintenance of memory cells? What are the factors allowing the maintenance of immune memory (regular contact with the pathogen or re-vaccination)? Secondly, what is the nature and quality (function / phenotype / location) of memory B and T cells? Finally, is it necessary to induce and maintain immunological memory against conserved proteins and/or to re-vaccinate against viral variants? What would be the consequences of repeated vaccination? These questions remain a subject of debate that will be further discussed. Since immunological memory is the cornerstone of vaccination, it is essential that we have a better understanding of its generation and maintenance over time as well as its contribution to recall responses during pandemics or after vaccination. PMID:20303671

  11. Rapid and specific influenza virus detection by functionalized magnetic nanoparticles and mass spectrometry

    PubMed Central

    2011-01-01

    Background The timely and accurate diagnosis of specific influenza virus strains is crucial to effective prophylaxis, vaccine preparation and early antiviral therapy. The detection of influenza A viruses is mainly accomplished using polymerase chain reaction (PCR) techniques or antibody-based assays. In conjugation with the immunoassay utilizing monoclonal antibody, mass spectrometry is an alternative to identify proteins derived from a target influenza virus. Taking advantage of the large surface area-to-volume ratio, antibody-conjugated magnetic nanoparticles can act as an effective probe to extract influenza virus for sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and on-bead mass spectrometric analysis. Results Iron oxide magnetic nanoparticles (MNP) were functionalized with H5N2 viral antibodies targeting the hemagglutinin protein and capped with methoxy-terminated ethylene glycol to suppress nonspecific binding. The antibody-conjugated MNPs possessed a high specificity to H5N2 virus without cross-reactivity with recombinant H5N1 viruses. The unambiguous identification of the captured hemagglutinin on magnetic nanoparticles was realized by SDS-PAGE visualization and peptide sequence identification using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Conclusions The assay combining efficient magnetic separation and MALDI-MS readout offers a rapid and sensitive method for virus screening. Direct on-MNP detection by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) provided high sensitivity (~103 EID50 per mL) and a timely diagnosis within one hour. The magnetic nanoparticles encapsulated with monoclonal antibodies could be used as a specific probe to distinguish different subtypes of influenza. PMID:22088100

  12. The Mutational Robustness of Influenza A Virus

    PubMed Central

    McCrone, John T.; Lauring, Adam S.

    2016-01-01

    A virus’ mutational robustness is described in terms of the strength and distribution of the mutational fitness effects, or MFE. The distribution of MFE is central to many questions in evolutionary theory and is a key parameter in models of molecular evolution. Here we define the mutational fitness effects in influenza A virus by generating 128 viruses, each with a single nucleotide mutation. In contrast to mutational scanning approaches, this strategy allowed us to unambiguously assign fitness values to individual mutations. The presence of each desired mutation and the absence of additional mutations were verified by next generation sequencing of each stock. A mutation was considered lethal only after we failed to rescue virus in three independent transfections. We measured the fitness of each viable mutant relative to the wild type by quantitative RT-PCR following direct competition on A549 cells. We found that 31.6% of the mutations in the genome-wide dataset were lethal and that the lethal fraction did not differ appreciably between the HA- and NA-encoding segments and the rest of the genome. Of the viable mutants, the fitness mean and standard deviation were 0.80 and 0.22 in the genome-wide dataset and best modeled as a beta distribution. The fitness impact of mutation was marginally lower in the segments coding for HA and NA (0.88 ± 0.16) than in the other 6 segments (0.78 ± 0.24), and their respective beta distributions had slightly different shape parameters. The results for influenza A virus are remarkably similar to our own analysis of CirSeq-derived fitness values from poliovirus and previously published data from other small, single stranded DNA and RNA viruses. These data suggest that genome size, and not nucleic acid type or mode of replication, is the main determinant of viral mutational fitness effects. PMID:27571422

  13. Avian influenza virus and free-ranging wild birds

    USGS Publications Warehouse

    Dierauf, Leslie A.; Karesh, W.B.; Ip, Hon S.; Gilardi, K.V.; Fischer, John R.

    2006-01-01

    Recent media and news reports and other information implicate wild birds in the spread of highly pathogenic avian influenza in Asia and Eastern Europe. Although there is little information concerning highly pathogenic avian influenza viruses in wild birds, scientists have amassed a large amount of data on low-pathogenicity avian influenza viruses during decades of research with wild birds. This knowledge can provide sound guidance to veterinarians, public health professionals, the general public, government agencies, and other entities with concerns about avian influenza.

  14. Inhibition of Influenza Virus Infection by a Novel Antiviral Peptide That Targets Viral Attachment to Cells▿

    PubMed Central

    Jones, Jeremy C.; Turpin, Elizabeth A.; Bultmann, Hermann; Brandt, Curtis R.; Schultz-Cherry, Stacey

    2006-01-01

    Influenza A viruses continue to cause widespread morbidity and mortality. There is an added concern that the highly pathogenic H5N1 influenza A viruses, currently found throughout many parts of the world, represent a serious public health threat and may result in a pandemic. Intervention strategies to halt an influenza epidemic or pandemic are a high priority, with an emphasis on vaccines and antiviral drugs. In these studies, we demonstrate that a 20-amino-acid peptide (EB, for entry blocker) derived from the signal sequence of fibroblast growth factor 4 exhibits broad-spectrum antiviral activity against influenza viruses including the H5N1 subtype in vitro. The EB peptide was protective in vivo, even when administered postinfection. Mechanistically, the EB peptide inhibits the attachment to the cellular receptor, preventing infection. Further studies demonstrated that the EB peptide specifically binds to the viral hemagglutinin protein. This novel peptide has potential value as a reagent to study virus attachment and as a future therapeutic. PMID:17005658

  15. Detection of antibodies against avian influenza virus by protein microarray using nucleoprotein expressed in insect cells

    PubMed Central

    ZHAO, Yuhui; WANG, Xiurong; CHEN, Pucheng; ZENG, Xianying; BAO, Hongmei; WANG, Yunhe; XU, Xiaolong; JIANG, Yongping; CHEN, Hualan; LI, Guangxing

    2014-01-01

    Avian influenza (AI) is an infectious disease caused by avian influenza viruses (AIVs) which belong to the influenza virus A group. AI causes tremendous economic losses in poultry industry and pose great threatens to human health. Active serologic surveillance is necessary to prevent and control the spread of AI. In this study, a protein microarray using nucleoprotein (NP) of H5N1 AIV expressed in insect cells was developed to detect antibodies against AIV NP protein. The protein microarray was used to test Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), AIV positive and negative sera. The results indicated that the protein microarray could hybridize specifically with antibodies against AIV with strong signals and without cross-hybridization. Moreover, 76 field serum samples were detected by microarray, enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition test (HI). The positive rate was 92.1% (70/76), 93.4% (71/76) and 89.4% (68/76) by protein microarray, ELISA and HI test, respectively. Compared with ELISA, the microarray showed 100% (20/20) agreement ratio in chicken and 98.2% (55/56) in ornamental bird. In conclusion, this method provides an alternative serological diagnosis for influenza antibody screening and will provide a basis for the development of protein microarrays that can be used to respectively detect antibodies of different AIV subtypes and other pathogens. PMID:25650059

  16. Detection of antibodies against avian influenza virus by protein microarray using nucleoprotein expressed in insect cells.

    PubMed

    Zhao, Yuhui; Wang, Xiurong; Chen, Pucheng; Zeng, Xianying; Bao, Hongmei; Wang, Yunhe; Xu, Xiaolong; Jiang, Yongping; Chen, Hualan; Li, Guangxing

    2015-04-01

    Avian influenza (AI) is an infectious disease caused by avian influenza viruses (AIVs) which belong to the influenza virus A group. AI causes tremendous economic losses in poultry industry and pose great threatens to human health. Active serologic surveillance is necessary to prevent and control the spread of AI. In this study, a protein microarray using nucleoprotein (NP) of H5N1 AIV expressed in insect cells was developed to detect antibodies against AIV NP protein. The protein microarray was used to test Newcastle disease virus (NDV), infectious bursal disease virus (IBDV), AIV positive and negative sera. The results indicated that the protein microarray could hybridize specifically with antibodies against AIV with strong signals and without cross-hybridization. Moreover, 76 field serum samples were detected by microarray, enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition test (HI). The positive rate was 92.1% (70/76), 93.4% (71/76) and 89.4% (68/76) by protein microarray, ELISA and HI test, respectively. Compared with ELISA, the microarray showed 100% (20/20) agreement ratio in chicken and 98.2% (55/56) in ornamental bird. In conclusion, this method provides an alternative serological diagnosis for influenza antibody screening and will provide a basis for the development of protein microarrays that can be used to respectively detect antibodies of different AIV subtypes and other pathogens. PMID:25650059

  17. Temporal association between the influenza virus and respiratory syncytial virus (RSV): RSV as a predictor of seasonal influenza.

    PubMed

    Míguez, A; Iftimi, A; Montes, F

    2016-09-01

    Epidemiologists agree that there is a prevailing seasonality in the presentation of epidemic waves of respiratory syncytial virus (RSV) infections and influenza. The aim of this study is to quantify the potential relationship between the activity of RSV, with respect to the influenza virus, in order to use the RSV seasonal curve as a predictor of the evolution of an influenza virus epidemic wave. Two statistical tools, logistic regression and time series, are used for predicting the evolution of influenza. Both logistic models and time series of influenza consider RSV information from previous weeks. Data consist of influenza and confirmed RSV cases reported in Comunitat Valenciana (Spain) during the period from week 40 (2010) to week 8 (2014). Binomial logistic regression models used to predict the two states of influenza wave, basal or peak, result in a rate of correct classification higher than 92% with the validation set. When a finer three-states categorization is established, basal, increasing peak and decreasing peak, the multinomial logistic model performs well in 88% of cases of the validation set. The ARMAX model fits well for influenza waves and shows good performance for short-term forecasts up to 3 weeks. The seasonal evolution of influenza virus can be predicted a minimum of 4 weeks in advance using logistic models based on RSV. It would be necessary to study more inter-pandemic seasons to establish a stronger relationship between the epidemic waves of both viruses. PMID:27165946

  18. Two novel reassortants of avian influenza A (H5N6) virus in China.

    PubMed

    Bi, Yuhai; Mei, Kun; Shi, Weifeng; Liu, Di; Yu, Xiaolan; Gao, Zhimin; Zhao, Lihua; Gao, George F; Chen, Jianjun; Chen, Quanjiao

    2015-05-01

    Eight avian influenza A (H5N6) viruses were isolated from live poultry markets (LPMs) in Sichuan and Jiangxi Provinces in China in 2014, including those close to the county where the human H5N6 infection occurred. Genetic and phylogenetic analyses revealed that these H5N6 viruses were novel reassortants between H5N1 clade 2.3.4 and H6N6 viruses, and had evolved into two distinct lineages (Sichuan and Jiangxi). Moreover, the human H5N6 virus was closely related to the avian-source viruses of Sichuan lineage. Notably, H5N6 viruses contained a T160A substitution in the haemagglutinin protein and an 11 aa deletion in the neuraminidase stalk, which may aid in enhancing viral affinity for human-like receptors and virulence in mammals. As the H5N1 virus infects humans through direct contact, infection with the novel H5N6 virus raised significant concerns that the H5 subtype was a likely candidate for a pandemic. Therefore, extensive and long-term surveillance of avian influenza viruses in LPMs is essential. PMID:25604926

  19. Isolation and characterization of influenza A viruses from environmental water at an overwintering site of migratory birds in Japan.

    PubMed

    Okuya, Kosuke; Kawabata, Toshiko; Nagano, Kiori; Tsukiyama-Kohara, Kyoko; Kusumoto, Isamu; Takase, Kozo; Ozawa, Makoto

    2015-12-01

    The Izumi plain in Kagoshima prefecture, Japan, is an overwintering site of more than 10,000 cranes. The wet paddy areas are artificially created to provide roosting sites for the cranes every winter. Since wild ducks, known to be a natural reservoir of influenza A viruses, also overwinter in this area, the cranes' roost water likely serves as a source of influenza A virus infection. To assess this potential risk, we collected 126 water samples from the cranes' roost in the 2012/2013 winter season for virus isolation. We isolated six influenza viruses of three subtypes (H3N8, H4N6, and H4N8) from the water samples collected in the months of November and December. Genetic analysis of our isolates indicated that these viruses were genetically similar to the low-pathogenic avian influenza viruses circulating among Eurasian waterfowl. These findings suggest the possibility of the cranes becoming infected with the avian influenza viruses that are present in their roost water. PMID:26392284

  20. Monitoring Avian Influenza A(H7N9) Virus through National Influenza-like Illness Surveillance, China

    PubMed Central

    Xu, Cuiling; Havers, Fiona; Wang, Lijie; Chen, Tao; Shi, Jinghong; Wang, Dayan; Yang, Jing; Yang, Lei; Widdowson, Marc-Alain

    2013-01-01

    In China during March 4–April 28, 2013, avian influenza A(H7N9) virus testing was performed on 20,739 specimens from patients with influenza-like illness in 10 provinces with confirmed human cases: 6 (0.03%) were positive, and increased numbers of unsubtypeable influenza-positive specimens were not seen. Careful monitoring and rapid characterization of influenza A(H7N9) and other influenza viruses remain critical. PMID:23879887

  1. Equine Influenza A(H3N8) Virus Infection in Cats

    PubMed Central

    Su, Shuo; Wang, Lifang; Fu, Xinliang; He, Shuyi; Hong, Malin; Zhou, Pei; Gray, Gregory

    2014-01-01

    Interspecies transmission of equine influenza A(H3N8) virus has resulted in establishment of a canine influenza virus. To determine if something similar could happen with cats, we experimentally infected 14 cats with the equine influenza A(H3N8) virus. All showed clinical signs, shed virus, and transmitted the virus to a contact cohort. PMID:25417790

  2. Simultaneous detection of avian influenza virus NP and H5 antibodies in chicken sera using a fluorescence microsphere immunoassay.

    PubMed

    Lupiani, Blanca; Mozisek, Blayne; Mason, Peter W; Lamichhane, Chinta; Reddy, Sanjay M

    2010-03-01

    Avian influenza (AI) surveillance in commercial poultry is accomplished by detecting the presence of antibodies to two group-specific antigens, NP and M1, using the agar gel immunodiffusion test. In order to determine the viral subtype responsible for the infection, positive samples must be further subtyped using the hemagglutination inhibition and neuraminidase inhibition tests. These tests are labor intensive and may take up to 4 days, thus slowing down responses to outbreaks. To expedite the subtyping of chicken sera we have developed a multiplex fluorescence microsphere immunoassay (FMIA), which allows for the simultaneous detection and subtyping of chicken sera to H5 influenza viruses. The FMIA was developed using NP (full length) and H5 (HA1 region) proteins expressed in baby hamster kidney cells using a Venezuela equine encephalitis virus replicon system. Both proteins were tagged with 6xHis at the carboxy-end and purified using cobalt-coated agarose beads. Purified H5 protein showed minimal cross-reactivity with anti-H2 serum, while no cross-reactivity was observed with sera to other AI virus (AIV) subtypes and other important poultry viral pathogens. In addition, and as expected, all the AIV sera tested reacted strongly with purified NP protein. Our results indicate that FMIA can be used for rapid subtyping of chicken sera. PMID:20521712

  3. Prevalence of canine influenza virus A (H3N8) in dogs in Germany.

    PubMed

    Schulz, Bianka; Klinkenberg, Christina; Fux, Robert; Anderson, Tara; de Benedictis, Paola; Hartmann, Katrin

    2014-10-01

    The aim of this study was to investigate the prevalence of CIV H3N8 in dogs in Germany. Blood samples from 272 clinically healthy dogs and 35 dogs with acute respiratory signs were screened for antibodies against influenza virus by ELISA and haemagglutination inhibition (HI) assay; positive samples were further tested by fluorescent antibody test (FAT) and subtype-specific HI assay. Nasal and pharyngeal swabs from all sick dogs were submitted for real-time (RT)-PCR for influenza virus RNA; PCR results were negative in all cases. One healthy and one sick dog tested positive for antibodies against influenza virus nucleoprotein by ELISA, but both were negative by subtype-specific HI assay and FAT, and were therefore considered false positive results. Thus, antibody prevalence against CIV H3N8 was 0% (0-1.24%, 95% CI). Currently, the risk for CIV H3N8 infection in the German dog population seems very low. PMID:25155218

  4. Influenza A Viruses in Wild Birds of the Pacific Flyway, 2005–2008

    PubMed Central

    Siembieda, Jennifer L.; Cardona, Carol; Anchell, Nichole; Dao, Nguyet; Reisen, William; Boyce, Walter

    2010-01-01

    Abstract Avian influenza viruses (AIVs) pose a significant threat to public health, and viral subtypes circulating in natural avian reservoirs can contribute to the emergence of pathogenic influenza viruses in humans. We investigated the prevalence and distribution of AIVs in 8826 migratory and resident wild birds in North America along the Pacific flyway, which is a major north–south migration pathway that overlaps with four other flyways in Alaska providing opportunities for mixing of Eurasian and American origin influenza viruses. Overall, the prevalence of AIVs was low (1%) among the wide range of avian species tested, but we detected AIVs in 69 hunter-harvested waterfowl (Anseriformes) sampled at a national wildlife refuge in California from October 2007 to January 2008. A wide range of subtypes were detected in waterfowl with H6N1, H10N7, H7N3, and H3N5 being the most common. We suspect H6N1 was introduced or remerged in 2007 at this key wintering site for waterfowl along the Pacific Flyway. Over a 3-week period, 13 H6N1 AIVs were isolated from two northern pintails (Anas acuta), three northern shovelers (Anas clypeata), three ring-necked ducks (Aythya collaris), four American widgeon (Anas americana), and one gadwall (Anas strepera). We conclude that a diverse array of AIVs was present and that cross-species transmission was occurring among waterfowl in the central valley wetlands of California. PMID:20059316

  5. Highly Pathogenic Avian Influenza Virus among Wild Birds in Mongolia

    PubMed Central

    Gilbert, Martin; Jambal, Losolmaa; Karesh, William B.; Fine, Amanda; Shiilegdamba, Enkhtuvshin; Dulam, Purevtseren; Sodnomdarjaa, Ruuragchaa; Ganzorig, Khuukhenbaatar; Batchuluun, Damdinjav; Tseveenmyadag, Natsagdorj; Bolortuya, Purevsuren; Cardona, Carol J.; Leung, Connie Y. H.; Peiris, J. S. Malik; Spackman, Erica; Swayne, David E.; Joly, Damien O.

    2012-01-01

    Mongolia combines a near absence of domestic poultry, with an abundance of migratory waterbirds, to create an ideal location to study the epidemiology of highly pathogenic avian influenza virus (HPAIV) in a purely wild bird system. Here we present the findings of active and passive surveillance for HPAIV subtype H5N1 in Mongolia from 2005–2011, together with the results of five outbreak investigations. In total eight HPAIV outbreaks were confirmed in Mongolia during this period. Of these, one was detected during active surveillance employed by this project, three by active surveillance performed by Mongolian government agencies, and four through passive surveillance. A further three outbreaks were recorded in the neighbouring Tyva Republic of Russia on a lake that bisects the international border. No HPAIV was isolated (cultured) from 7,855 environmental fecal samples (primarily from ducks), or from 2,765 live, clinically healthy birds captured during active surveillance (primarily shelducks, geese and swans), while four HPAIVs were isolated from 141 clinically ill or dead birds located through active surveillance. Two low pathogenic avian influenza viruses (LPAIV) were cultured from ill or dead birds during active surveillance, while environmental feces and live healthy birds yielded 56 and 1 LPAIV respectively. All Mongolian outbreaks occurred in 2005 and 2006 (clade 2.2), or 2009 and 2010 (clade 2.3.2.1); all years in which spring HPAIV outbreaks were reported in Tibet and/or Qinghai provinces in China. The occurrence of outbreaks in areas deficient in domestic poultry is strong evidence that wild birds can carry HPAIV over at least moderate distances. However, failure to detect further outbreaks of clade 2.2 after June 2006, and clade 2.3.2.1 after June 2010 suggests that wild birds migrating to and from Mongolia may not be competent as indefinite reservoirs of HPAIV, or that HPAIV did not reach susceptible populations during our study. PMID:22984464

  6. Genetics, receptor binding property, and transmissibility in mammals of naturally isolated H9N2 Avian Influenza viruses.

    PubMed

    Li, Xuyong; Shi, Jianzhong; Guo, Jing; 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

    2014-11-01

    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

  7. 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

  8. Characterization of Avian Influenza and Newcastle Disease Viruses from Poultry in Libya.

    PubMed

    Kammon, Abdulwahab; Heidari, Alireza; Dayhum, Abdunaser; Eldaghayes, Ibrahim; Sharif, Monier; Monne, Isabela; Cattoli, Giovanni; Asheg, Abdulatif; Farhat, Milad; Kraim, Elforjani

    2015-09-01

    On March 2013, the Libyan poultry industry faced severe outbreaks due to mixed infections of APMV-1 (Newcastle disease) and low pathogenic avian influenza (AI) of the H9N2 subtype which were causing high mortality and great economic losses. APMV-1 and H9N2 were isolated and characterized. Genetic sequencing of the APMV-1/chicken/Libya/13VIR/ 7225-1/2013 isolate revealed the presence of a velogenic APMV-1 belonging to lineage 5 (GRRRQKR*F Lin.5) or genotype VII in class II, according to the nomenclature in use. Three AI viruses of the H9N2 subtype, namely A/avian/Libya/13VIR7225-2/2013, A/avian/Libya/13VIR7225-3/2013, and A/avian/Libya/13VIR7225-5/2013, were isolated and found to belong to the G1 lineage. Analysis of amino acid sequences showed that the analyzed H9N2 viruses contained the amino acid Leu at position 226 (H3 numbering) at the receptor binding site of the HA, responsible for human virus-like receptor specificity. On March 2014, an outbreak of highly pathogenic avian influenza (HPAI) virus of the H5N1 subtype was diagnosed in a backyard poultry farm in an eastern region of Libya. The H5N1 isolate (A/chicken/Libya/14VIR2749-16/2014) was detected by real time RT-PCR (rRT-PCR). Genetic characterization of the HA gene revealed that the identified subtype was highly pathogenic, belonged to the 2.2.1 lineage, and clustered with recent Egyptian viruses. This study revealed the presence of a velogenic APMV-1 genotype and of two influenza subtypes, namely HPAI H5N1 and H9N2, which are of major interest for public and animal health. Considering these findings, more investigations must be undertaken to establish and implement adequate influenza surveillance programs; this would allow better study of the epidemiology of APMV-1 genotype VII in Libya and evaluation of the current vaccination strategies. PMID:26478162

  9. Landscape attributes driving avian influenza virus circulation in the Lake Alaotra region of Madagascar.

    PubMed

    Guerrini, Laure; Paul, Mathilde C; Leger, Lucas; Andriamanivo, Harentsoaniaina R; Maminiaina, Olivier F; Jourdan, Marion; Molia, Sophie; Rakotondravao, René; Chevalier, Véronique

    2014-05-01

    While the spatial pattern of the highly pathogenic avian influenza H5N1 virus has been studied throughout Southeast Asia, little is known on the spatial risk factors for avian influenza in Africa. In the present paper, we combined serological data from poultry and remotely sensed environmental factors in the Lake Alaotra region of Madagascar to explore for any association between avian influenza and landscape variables. Serological data from cross-sectional surveys carried out on poultry in 2008 and 2009 were examined together with a Landsat 7 satellite image analysed using supervised classification. The dominant landscape features in a 1-km buffer around farmhouses and distance to the closest water body were extracted. A total of 1,038 individual bird blood samples emanating from 241 flocks were analysed, and the association between avian influenza seroprevalence and these landcape variables was quantified using logistic regression models. No evidence of the presence of H5 or H7 avian influenza subtypes was found, suggesting that only low pathogenic avian influenza (LPAI) circulated. Three predominant land cover classes were identified around the poultry farms: grassland savannah, rice paddy fields and wetlands. A significant negative relationship was found between LPAI seroprevalence and distance to the closest body of water. We also found that LPAI seroprevalence was higher in farms characterised by predominant wetlands or rice landscapes than in those surrounded by dry savannah. Results from this study suggest that if highly pathogenic avian influenza H5N1 virus were introduced in Madagascar, the environmental conditions that prevail in Lake Alaotra region may allow the virus to spread and persist. PMID:24893021

  10. Evaluation of Screening Assays for the Detection of Influenza A Virus Serum Antibodies in Swine.

    PubMed

    Goodell, C K; Prickett, J; Kittawornrat, A; Johnson, J; Zhang, J; Wang, C; Zimmerman, J J

    2016-02-01

    Increased surveillance of influenza A virus (IAV) infections in human and swine populations is mandated by public health and animal health concerns. Antibody assays have proven useful in previous surveillance programmes because antibodies provide a record of prior exposure and the technology is inexpensive. The objective of this research was to compare the performance of influenza serum antibody assays using samples collected from pigs (vaccinated or unvaccinated) inoculated with either A/Swine/OH/511445/2007 γ H1N1 virus or A/Swine/Illinois/02907/2009 Cluster IV H3N2 virus and followed for 42 days. Weekly serum samples were tested for anti-IAV antibodies using homologous and heterologous haemagglutination-inhibition (HI) assays, commercial swine influenza H1N1 and H3N2 indirect ELISAs, and a commercial influenza nucleoprotein (NP)-blocking ELISA. The homologous HIs showed 100% diagnostic sensitivity, but largely failed to detect infection with the heterologous virus. With diagnostic sensitivities of 1.4% and 4.9%, respectively, the H1N1 and H3N2 indirect ELISAs were ineffective at detecting IAV antibodies in swine infected with the contemporary influenza viruses used in the study. At a cut-off of S/N ≤ 0.60, the sensitivity and specificity of the NP-blocking ELISA were estimated at 95.5% and 99.6%, respectively. Statistically significant factors which affected S/N results include vaccination status, inoculum (virus subtype), day post-inoculation and the interactions between those factors (P < 0.0001). Serum antibodies against NP provide an ideal universal diagnostic screening target and could provide a cost-effective approach for the detection and surveillance of IAV infections in swine populations. PMID:24571447

  11. Live poultry market workers are susceptible to both avian and swine influenza viruses, Guangdong Province, China.

    PubMed

    Chen, Jidang; Ma, Jun; White, Sarah K; Cao, Zhenpeng; Zhen, Yun; He, Shuyi; Zhu, Wanjun; Ke, Changwen; Zhang, Yongbiao; Su, Shuo; Zhang, Guihong

    2015-12-31

    Guangdong Province is recognized for dense populations of humans, pigs, poultry and pets. In order to evaluate the threat of viral infection faced by those working with animals, a cross-sectional, sero-epidemiological study was conducted in Guangdong between December 2013 and January 2014. Individuals working with swine, at poultry farms, or live poultry markets (LPM), and veterinarians, and controls not exposed to animals were enrolled in this study and 11 (4 human, 3 swine, 3 avian, and 1 canine) influenza A viruses were used in hemagglutination inhibition (HI) assays (7 strains) and the cross-reactivity test (9 strains) in which 5 strains were used in both tests. Univariate analysis was performed to identify which variables were significantly associated with seropositivity. Odds ratios (OR) revealed that swine workers had a significantly higher risk of elevated antibodies against A/swine/Guangdong/L6/2009(H1N1), a classical swine virus, and A/swine/Guangdong/SS1/2012(H1N1), a Eurasian avian-like swine virus than non-exposed controls. Poultry farm workers were at a higher risk of infection with avian influenza H7N9 and H9N2. LPM workers were at a higher risk of infection with 3 subtypes of avian influenza, H5N1, H7N9, and H9N2. Interestingly, the OR also indicated that LPM workers were at risk of H1N1 swine influenza virus infection, perhaps due to the presence of pigs in the LPM. While partial confounding by cross-reactive antibodies against human viruses or vaccines cannot be ruled out, our data suggests that animal exposed people as are more likely to have antibodies against animal influenza viruses. PMID:26476563

  12. Identification of Stabilizing Mutations in an H5 Hemagglutinin Influenza Virus Protein

    PubMed Central

    Hanson, Anthony; Imai, Masaki; Hatta, Masato; McBride, Ryan; Imai, Hirotaka; Taft, Andrew; Zhong, Gongxun; Watanabe, Tokiko; Suzuki, Yasuo; Neumann, Gabriele; Paulson, James C.

    2015-01-01

    ABSTRACT Highly pathogenic avian influenza viruses of the H5N1 subtype continue to circulate in poultry in Asia, Africa, and the Middle East. Recently, outbreaks of novel reassortant H5 viruses have also occurred in North America. Although the number of human infections with highly pathogenic H5N1 influenza viruses continues to rise, these viruses remain unable to efficiently transmit between humans. However, we and others have identified H5 viruses capable of respiratory droplet transmission in ferrets. Two experimentally introduced mutations in the viral hemagglutinin (HA) receptor-binding domain conferred binding to human-type receptors but reduced HA stability. Compensatory mutations in HA (acquired during virus replication in ferrets) were essential to restore HA stability. These stabilizing mutations in HA also affected the pH at which HA undergoes an irreversible switch to its fusogenic form in host endosomes, a crucial step for virus infectivity. To identify additional stabilizing mutations in an H5 HA, we subjected a virus library possessing random mutations in the ectodomain of an H5 HA (altered to bind human-type receptors) to three rounds of treatment at 50°C. We isolated several mutants that maintained their human-type receptor-binding preference but acquired an appreciable increase in heat stability and underwent membrane fusion at a lower pH; collectively, these properties may aid H5 virus respiratory droplet transmission in mammals. IMPORTANCE We have identified mutations in HA that increase its heat stability and affect the pH that triggers an irreversible conformational change (a prerequisite for virus infectivity). These mutations were identified in the genetic background of an H5 HA protein that was mutated to bind to human cells. The ability to bind to human-type receptors, together with physical stability and an altered pH threshold for HA conformational change, may facilitate avian influenza virus transmission via respiratory droplets in

  13. A Review of Evidence that Equine Influenza Viruses Are Zoonotic.

    PubMed

    Xie, Tai; Anderson, Benjamin D; Daramragchaa, Ulziimaa; Chuluunbaatar, Maitsetset; Gray, Gregory C

    2016-01-01

    Among scientists, there exist mixed opinions whether equine influenza viruses infect man. In this report, we summarize a 2016 systematic and comprehensive review of the English, Chinese, and Mongolian scientific literature regarding evidence for equine influenza virus infections in man. Searches of PubMed, Web of Knowledge, ProQuest, CNKI, Chongqing VIP Database, Wanfang Data and MongolMed yielded 2831 articles, of which 16 met the inclusion criteria for this review. Considering these 16 publications, there was considerable experimental and observational evidence that at least H3N8 equine influenza viruses have occasionally infected man. In this review we summarize the most salient scientific reports. PMID:27420100

  14. 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. PMID:27309293

  15. Multiyear Serological Surveillance of Notifiable Influenza A Viruses in Belgian Poultry: A Retrospective Analysis.

    PubMed

    Marché, Sylvie; Houdart, Philippe; van den Berg, Thierry; Lambrecht, Bénédicte

    2015-12-01

    Surveillance of notifiable avian influenza (NAI) virus is mandatory in European member states, and each year a serological survey is performed to detect H5 and H7 circulation in poultry holdings. In Belgium, this serological monitoring is a combination of a stratified and a risk-based approach and is applied to commercial holdings with more than 200 birds. Moreover, a competitive nucleoprotein (NP) ELISA has been used as first screening method since 2010. A retrospective analysis of the serological monitoring performed from 2007 through 2013 showed sporadic circulation of notifiable low-pathogenicity avian influenza (LPAI) viruses in Belgian holdings with a fluctuating apparent flock seroprevalence according to years and species. Overall, the highest apparent flock seroprevalence was detected for the H5 subtype in domestic Anatidae, with 20%-50% for breeding geese and 4%-9% for fattening ducks. Positive serology against non-H5/H7 viruses was also observed in the same species with the use of the IDScreen influenza A antibody competition ELISA kit (ID-vet NP ELISA), and confirmed by isolation of H2, H3, H6, and H9 LPAI viruses. Among Galliformes, the apparent flock seroprevalence was lower, ranging between 0.3% and 1.3%. Circulation of notifiable LPAI viruses was only observed in laying hens with a similar seroprevalence for H5 and H7. Based on ID-vet NP ELISA results, no circulation of LPAI viruses, regardless the subtype, was observed in breeding chickens and fattening turkeys. Retrospectively, the use of an ELISA as first-line test not only reduced the number of hemagglutination inhibition tests to be performed, but also gave a broader evaluation of the prevalence of LPAI viruses in general, and might help to identify the most at-risk farms. PMID:26629630

  16. Multiyear Serological Surveillance of Notifiable Influenza A Viruses in Belgian Poultry: A Retrospective Analysis.

    PubMed

    Marché, Sylvie; Houdart, Philippe; van den Berg, Thierry; Lambrecht, Bénédicte

    2016-05-01

    Surveillance of notifiable avian influenza (NAI) virus is mandatory in European member states, and each year a serological survey is performed to detect H5 and H7 circulation in poultry holdings. In Belgium, this serological monitoring is a combination of a stratified and a risk-based approach and is applied to commercial holdings with more than 200 birds. Moreover, a competitive nucleoprotein (NP) ELISA has been used as first screening method since 2010. A retrospective analysis of the serological monitoring performed from 2007 through 2013 showed sporadic circulation of notifiable low-pathogenicity avian influenza (LPAI) viruses in Belgian holdings with a fluctuating apparent flock seroprevalence according to years and species. Overall, the highest apparent flock seroprevalence was detected for the H5 subtype in domestic Anatidae, with 20%-50% for breeding geese and 4%-9% for fattening ducks. Positive serology against non-H5/H7 viruses was also observed in the same species with the use of the IDScreen influenza A antibody competition ELISA kit (ID-vet NP ELISA), and confirmed by isolation of H2, H3, H6, and H9 LPAI viruses. Among Galliformes, the apparent flock seroprevalence was lower, ranging between 0.3% and 1.3%. Circulation of notifiable LPAI viruses was only observed in laying hens with a similar seroprevalence for H5 and H7. Based on ID-vet NP ELISA results, no circulation of LPAI viruses, regardless the subtype, was observed in breeding chickens and fattening turkeys. Retrospectively, the use of an ELISA as first-line test not only reduced the number of hemagglutination inhibition tests to be performed, but also gave a broader evaluation of the prevalence of LPAI viruses in general, and might help to identify the most at-risk farms. PMID:27309088

  17. Differential age susceptibility to influenza B/Victoria lineage viruses in the 2015 Australian influenza season.

    PubMed

    Barr, Ian G; Vijaykrishna, Dhanasekaran; Sullivan, Sheena G

    2016-01-01

    Influenza B viruses make up an important part of the burden from seasonal influenza globally. The 2015 season in Australia saw an unusual predominance of influenza B with a distinctive switch during the season from B/Yamagata/16/88 lineage viruses to B/Victoria/2/87 lineage viruses. We also noted significant differences in the age groups infected by the different B lineages, with B/Victoria infecting a younger population than B/Yamagata, that could not be explained by potential prior exposure. PMID:26848118

  18. Identification of morphological differences between avian influenza A viruses grown in chicken and duck cells.

    PubMed

    Al-Mubarak, Firas; Daly, Janet; Christie, Denise; Fountain, Donna; Dunham, Stephen P

    2015-03-01

    Although wild ducks are considered to be the major reservoirs for most influenza A virus subtypes, they are typically resistant to the effects of the infection. In contrast, certain influenza viruses may be highly pathogenic in other avian hosts such as chickens and turkeys, causing severe illness and death. Following in vitro infection of chicken and duck embryo fibroblasts (CEF and DEF) with low pathogenic avian influenza (LPAI) viruses, duck cells die more rapidly and produce fewer infectious virions than chicken cells. In the current study, the morphology of viruses produced from CEF and DEF cells infected with low pathogenic avian H2N3 was examined. Transmission electron microscopy showed that viruses budding from duck cells were elongated, while chicken cells produced mostly spherical virions; similar differences were observed in viral supernatants. Sequencing of the influenza genome of chicken- and duck-derived H2N3 LPAI revealed no differences, implicating host cell determinants as responsible for differences in virus morphology. Both DEF and CEF cells produced filamentous virions of equine H3N8 (where virus morphology is determined by the matrix gene). DEF cells produced filamentous or short filament virions of equine H3N8 and avian H2N3, respectively, even after actin disruption with cytochalasin D. These findings suggest that cellular factors other than actin are responsible for the formation of filamentous virions in DEF cells. The formation of elongated virions in duck cells may account for the reduced number of infectious virions produced and could have implications for virus transmission or maintenance in the reservoir host. PMID:25613009

  19. Human infection with an avian influenza A (H9N2) virus in the middle region of China.

    PubMed

    Huang, Yiwei; Li, Xiaodan; Zhang, Hong; Chen, Bozhong; Jiang, Yonglin; Yang, Lei; Zhu, Wenfei; Hu, Shixiong; Zhou, Siyu; Tang, Yunli; Xiang, Xingyu; Li, Fangcai; Li, Wenchao; Gao, Lidong

    2015-10-01

    During the epidemic period of the novel H7N9 viruses, an influenza A (H9N2) virus was isolated from a 7-year-old boy with influenza-like illness in Yongzhou city of Hunan province in November 2013. To identify the possible source of infection, environmental specimens collected from local live poultry markets epidemiologically linked to the human case in Yongzhou city were tested for influenza type A and its subtypes H5, H7, and H9 using real-time RT-PCR methods as well as virus isolation, and four other H9N2 viruses were isolated. The real-time RT-PCR results showed that the environment was highly contaminated with avian influenza H9 subtype viruses (18.0%). Sequencing analyses revealed that the virus isolated from the patient, which was highly similar (98.5-99.8%) to one of isolates from environment in complete genome sequences, was of avian origin. Based on phylogenetic and antigenic analyses, it belonged to genotype S and Y280 lineage. In addition, the virus exhibited high homology (95.7-99.5%) of all six internal gene lineages with the novel H7N9 and H10N8 viruses which caused epidemic and endemic in China. Meanwhile, it carried several mammalian adapted molecular residues including Q226L in HA protein, L13P in PB1 protein, K356R, S409N in PA protein, V15I in M1 protein, I28V, L55F in M2 protein, and E227K in NS protein. These findings reinforce the significance of continuous surveillance of H9N2 influenza viruses. PMID:25965534

  20. Aronia melanocarpa and its components demonstrate antiviral activity against influenza viruses.

    PubMed

    Park, Sehee; Kim, Jin Il; Lee, Ilseob; Lee, Sangmoo; Hwang, Min-Woong; Bae, Joon-Yong; Heo, Jun; Kim, Donghwan; Han, Sang-Zin; Park, Man-Seong

    2013-10-11

    The influenza virus is highly contagious in human populations around the world and results in approximately 250,000-500,000 deaths annually. Vaccines and antiviral drugs are commonly used to protect susceptible individuals. However, the antigenic mismatch of vaccines and the emergence of resistant strains against the currently available antiviral drugs have generated an urgent necessity to develop a novel broad-spectrum anti-influenza agent. Here we report that Aronia melanocarpa (black chokeberry, Aronia), the fruit of a perennial shrub species that contains several polyphenolic constituents, possesses in vitro and in vivo efficacy against different subtypes of influenza viruses including an oseltamivir-resistant strain. These anti-influenza properties of Aronia were attributed to two constituents, ellagic acid and myricetin. In an in vivo therapeutic mouse model, Aronia, ellagic acid, and myricetin protected mice against lethal challenge. Based on these results, we suggest that Aronia is a valuable source for antiviral agents and that ellagic acid and myricetin have potential as influenza therapeutics. PMID:24012672

  1. Vaccine-Induced Antibodies that Neutralize Group 1 and Group 2 Influenza A Viruses.

    PubMed

    Joyce, M Gordon; Wheatley, Adam K; Thomas, Paul V; Chuang, Gwo-Yu; Soto, Cinque; Bailer, Robert T; Druz, Aliaksandr; Georgiev, Ivelin S; Gillespie, Rebecca A; Kanekiyo, Masaru; Kong, Wing-Pui; Leung, Kwanyee; Narpala, Sandeep N; Prabhakaran, Madhu S; Yang, Eun Sung; Zhang, Baoshan; Zhang, Yi; Asokan, Mangaiarkarasi; Boyington, Jeffrey C; Bylund, Tatsiana; Darko, Sam; Lees, Christopher R; Ransier, Amy; Shen, Chen-Hsiang; Wang, Lingshu; Whittle, James R; Wu, Xueling; Yassine, Hadi M; Santos, Celia; Matsuoka, Yumiko; Tsybovsky, Yaroslav; Baxa, Ulrich; Mullikin, James C; Subbarao, Kanta; Douek, Daniel C; Graham, Barney S; Koup, Richard A; Ledgerwood, Julie E; Roederer, Mario; Shapiro, Lawrence; Kwong, Peter D; Mascola, John R; McDermott, Adrian B

    2016-07-28

    Antibodies capable of neutralizing divergent influenza A viruses could form the basis of a universal vaccine. Here, from subjects enrolled in an H5N1 DNA/MIV-prime-boost influenza vaccine trial, we sorted hemagglutinin cross-reactive memory B cells and identified three antibody classes, each capable of neutralizing diverse subtypes of group 1 and group 2 influenza A viruses. Co-crystal structures with hemagglutinin revealed that each class utilized characteristic germline genes and convergent sequence motifs to recognize overlapping epitopes in the hemagglutinin stem. All six analyzed subjects had sequences from at least one multidonor class, and-in half the subjects-multidonor-class sequences were recovered from >40% of cross-reactive B cells. By contrast, these multidonor-class sequences were rare in published antibody datasets. Vaccination with a divergent hemagglutinin can thus increase the frequency of B cells encoding broad influenza A-neutralizing antibodies. We propose the sequence signature-quantified prevalence of these B cells as a metric to guide universal influenza A immunization strategies. PMID:27453470

  2. Rewiring the RNAs of influenza virus to prevent reassortment

    PubMed Central

    Gao, Qinshan; Palese, Peter

    2009-01-01

    Influenza viruses contain segmented, negative-strand RNA genomes. Genome segmentation facilitates reassortment between different influenza virus strains infecting the same cell. This phenomenon results in the rapid exchange of RNA segments. In this study, we have developed a method to prevent the free reassortment of influenza A virus RNAs by rewiring their packaging signals. Specific packaging signals for individual influenza virus RNA segments are located in the 5′ and 3′ noncoding regions as well as in the terminal regions of the ORF of an RNA segment.