distribution of sequence differences in influenza n9 neuraminidase of tern and whale viruses and crystallization of the whale neuraminidase complexed with antibodies.neuraminidase genes from a/tern/australia/g70c/75 (h11n9) and a/whale/maine/1/84 (h13n9) influenza viruses have been sequenced. seventy-two nucleotide changes were found, 17 of which result in changes in the amino acid sequence of the neuraminidase; 3 in the stalk region and 14 in the heads. to our surprise, all of the sequence changes in the head region are located on the base of the neuraminidase tetramer, resulting in conservation of antigenic sites on top of the neuraminidase which vary exte ...19873660585
isolation of influenza a viruses from birds in great britain during 1980 and 1981.during 1980 and 1981 influenza a viruses of subtypes h3n2, h3n8, h4n1, h4n6, h6n2, h6n8, h7n7, h11n8 and h11n9 were isolated from birds in great britain, usually as a result of investigations of disease or death. however, all viruses were shown to be of low virulence for chickens in pathogenicity index tests. there was one occurrence of influenza virus infection of turkeys (h6n8) but viruses were frequently obtained from domestic ducks. other viruses were isolated from exotic birds in zoos or bi ...19826815876
characterization of the influenza a virus gene pool in avian species in southern china: was h6n1 a derivative or a precursor of h5n1?in 1997, an h5n1 influenza virus outbreak occurred in chickens in hong kong, and the virus was transmitted directly to humans. because there is limited information about the avian influenza virus reservoir in that region, we genetically characterized virus strains isolated in hong kong during the 1997 outbreak. we sequenced the gene segments of a heterogeneous group of viruses of seven different serotypes (h3n8, h4n8, h6n1, h6n9, h11n1, h11n9, and h11n8) isolated from various bird species. the p ...200010864640
avian influenza among waterfowl hunters and wildlife professionals.we report serologic evidence of avian influenza infection in 1 duck hunter and 2 wildlife professionals with extensive histories of wild waterfowl and game bird exposure. two laboratory methods showed evidence of past infection with influenza a/h11n9, a less common virus strain in wild ducks, in these 3 persons.200616965717
virologic findings in selected free-range mule duck farms at high risk for avian influenza infection.prevalence of avian influenza infection in free-range mule ducks (a cross between muscovy [cairina moschata domesticus] and pekin ducks [anas platyrhychos domesticus]) is a matter of concern and deserves particular attention. thus, cloacal swabs were collected blindly from 30 targeted mule flocks at 4, 8, and 12 wk of age between october 2004 and january 2005. they were stored until selection. on the basis of a positive h5 antibody detection at 12 wk of age with the use of four h5 antigens, the ...200717494595
avian influenza virus screening in wild waterfowl in norway, 2005.the prevalence of influenza a virus infection, and the distribution of different subtypes of the virus, were studied in 604 geese and ducks shot during ordinary hunting 2005. the study was based upon molecular screening of cloacal swabs taken by the hunters. the sampling included the following species: greylag (anser anser), mallard (anas platyrhynchos), wigeon (anas penelope), teal (anas crecca), goosander (mergus merganser), tufted duck (aythya fuligula), common scoter (melanitta nigra), golde ...200717494599
surveillance of avian influenza viruses in northern pintails (anas acuta) in tohoku district, japan.among winter migratory waterfowl, northern pintails (anas acuta), in one of the largest flocks in tohoku district, northeast japan, were surveyed for influenza a viruses at five wintering sites in three prefectures, viz., aomori, akita, and miyagi. a total of 38 influenza a viruses were isolated from 2066 fecal samples collected during november 2006 through march 2007. the overall isolation rate was 1.84%. eleven different subtypes were isolated, including nine h5n2, seven h6n8, seven h10n1, fou ...200818459295
genetic and phenotypic characterization of a low-pathogenicity avian influenza h11n9 h11n9 low-pathogenicity avian influenza virus, a/duck/wa/663/97, was isolated from a sick mandarin duck kept in an outdoor bird exhibit. genetic and phenotypic characterization of the virus suggested that it originated from free-flying birds, a concept supported by genetic similarity with waterfowl isolates from the same geographic area and time period. this duck-origin virus had genetic features typical of h11 and n9 viruses, including no neuraminidase stalk deletion, no differences in putat ...200818825481
immune-related gene expression in response to h11n9 low pathogenic avian influenza virus infection in chicken and pekin duck peripheral blood mononuclear cells.the duck and chicken are important hosts of avian influenza virus (aiv) with distinctive responses to infection. frequently, aiv infections in ducks are asymptomatic and long-lasting in contrast to the clinically apparent and transient infections observed in chickens. these differences may be due in part to the host response to aiv infection. using real-time quantitative pcr, we examined the expression of immune-related genes in response to low pathogenic aiv h11n9 infection in peripheral blood ...200919250679
an avian influenza a(h11n1) virus from a wild aquatic bird revealing a unique eurasian-american genetic reassortment.influenza surveillance in different wild bird populations is critical for understanding the persistence, transmission and evolution of these viruses. avian influenza (ai) surveillance was undertaken in wild migratory and resident birds during the period 2007-2008, in view of the outbreaks of highly pathogenic ai (hpai) h5n1 in poultry in india since 2006. in this study, we present the whole genome sequence data along with the genetic and virological characterization of an influenza a(h11n1) viru ...201020440548
human influenza is more effective than avian influenza at antiviral suppression in airway cells.airway epithelial cells are the initial site of infection with influenza viruses. the innate immune responses of airway epithelial cells to infection are important in limiting virus replication and spread. however, relatively little is known about the importance of this innate antiviral response to infection. avian influenza viruses are a potential source of future pandemics, therefore it is critical to examine the effectiveness of the host antiviral system to different influenza viruses. we use ...201020705938
characterization of influenza a viruses isolated from wild waterfowl in zambia.although the quest to clarify the role of wild birds in the spread of the highly pathogenic h5n1 avian influenza virus (aiv) has yielded considerable data on aivs in wild birds worldwide, information regarding the ecology and epidemiology of aivs in african wild birds is still very limited. during aiv surveillance in zambia (2008-2009), 12 viruses of distinct subtypes (h3n8, h4n6, h6n2, h9n1 and h11n9) were isolated from wild waterfowl. phylogenetic analyses demonstrated that all the isolates we ...201121367986
phylogenetic analysis of avian influenza viruses of h11 subtype isolated in kazakhstan.avian influenza viruses a/turkey/almaty/535/04 (h11n9) and a/herring gull/atyrau/2186/07 (h11n2) isolated in kazakhstan were characterized as low pathogenic in biological and genetic studies. putative glycosylation sites were identical to the putative sites in published h11, n2, and n9 isolates sequences. compared with published data no additional basic amino acid residues were found in the hemagglutinin (ha) cleavage site of these kazakhstan strains. phylogenetic analysis revealed a rare case o ...201121461588
Characterization of avian influenza viruses isolated from domestic ducks in Vietnam in 2009 and 2010.In the surveillance of avian influenza in Vietnam, 26 H9N2, 1 H3N2, 1 H3N8, 7 H4N6, 3 H11N3, and 1 H11N9 viruses were isolated from tracheal and cloacal swab samples of 300 domestic ducks in April 2009, and 1 H9N6 virus from 300 bird samples in March 2010. Out of the 27 H9 virus isolates, the hemagglutinins of 18 strains were genetically classified as belonging to the sublineage G1, and the other nine belonged to the Korean sublineage. Phylogenetic analysis revealed that one of the 27 H9 viruses ...201122068881
influenza-a viruses in ducks in northwestern minnesota: fine scale spatial and temporal variation in prevalence and subtype diversity.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 d ...201121931636
duck interferon-inducible transmembrane protein 3 mediates restriction of influenza viruses.interferon-inducible transmembrane proteins (ifitms) can restrict the entry of a wide range of viruses. ifitm3 localizes to endosomes and can potently restrict the replication of influenza a viruses (iav) and several other viruses that also enter host cells through the endocytic pathway. here, we investigate whether ifitms are involved in protection in ducks, the natural host of influenza virus. we identify and sequence duck ifitm1, ifitm2, ifitm3, and ifitm5. using quantitative pcr (qpcr), we d ...201526468537
local-scale diversity and between-year "frozen evolution" of avian influenza a viruses in nature.influenza a virus (iav) in wild bird reservoir hosts is characterized by the perpetuation in a plethora of subtype and genotype constellations. multiyear monitoring studies carried out during the last two decades worldwide have provided a large body of knowledge regarding the ecology of iav in wild birds. nevertheless, other issues of avian iav evolution have not been fully elucidated, such as the complexity and dynamics of genetic interactions between the co-circulating iav genomes taking place ...201425075739
genetic analysis of a novel reassortant h11n9 isolated from waterfowl in south korea in 2016.aquatic birds are known to harbor all the known influenza a viruses. in the winter of january 2016, we surveyed influenza a virus in the feces of migratory birds in south korea. the novel re-assorted h11n9 avian influenza virus, which contains genes from avian influenza viruses of poultry and wild birds, was isolated. the polymerase basic 2 (pb2), polymerase basic 1 (pb1), hemagglutinin (ha), and nucleoprotein (np) genes were most closely related to those of domestic duck-origin avian influenza ...201728386784
suppressor of cytokine signaling (socs)5 ameliorates influenza infection via inhibition of egfr signaling.influenza virus infections have a significant impact on global human health. individuals with suppressed immunity, or suffering from chronic inflammatory conditions such as copd, are particularly susceptible to influenza. here we show that suppressor of cytokine signaling (socs) five has a pivotal role in restricting influenza a virus in the airway epithelium, through the regulation of epidermal growth factor receptor (egfr). socs5-deficient mice exhibit heightened disease severity, with increas ...201728195529
characterization of a reassortant h11n9 subtype avian influenza virus isolated from bean goose along the east asian-australian flyway.during the surveillance of avian influenza viruses in the dongxi lake wetland of hubei in 2015-2016, an h11n9 avian influenza virus was isolated from a bean goose (anser fabalis). phylogenetic analysis showed that the ha gene of this isolate belongs to the north american lineage; however, the na and the internal genes of the isolate were generated from the eurasian lineage. this strain had reduced pathogenicity in mice and was capable of replication in the mouse lung without prior adaptation. th ...201727730427
tunable and label-free virus enrichment for ultrasensitive virus detection using carbon nanotube arrays.viral infectious diseases can erupt unpredictably, spread rapidly, and ravage mass populations. although established methods, such as polymerase chain reaction, virus isolation, and next-generation sequencing have been used to detect viruses, field samples with low virus count pose major challenges in virus surveillance and discovery. we report a unique carbon nanotube size-tunable enrichment microdevice (cnt-stem) that efficiently enriches and concentrates viruses collected from field samples. ...201627730213
detection of reassortant avian influenza a (h11n9) virus in environmental samples from live poultry markets in china.avian influenza viruses have caused human infection and posed the pandemic potential. live poultry markets are considered as a source of human infection with avian influenza viruses. avian influenza routine surveillance of live poultry markets is taken annually in china. we isolated the 2 h11n9 influenza virus from the surveillance program. to better understand the risk caused by these new viruses, we characterize the genetic and pathogenicity of the two viruses.201627268229
molecular characterization of subtype h11n9 avian influenza virus isolated from shorebirds in brazil.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 a ...201526689791
rapid genome sequencing and characterization of novel avian-origin influenza a h7n9 virus directly from clinical sample by semiconductor sequencing.recent outbreaks of severe pneumonia or acute respiratory distress syndrome have attracted much public interest. rapid and accurate diagnosis of the causative agent is key for an adequate response to suspected outbreaks.201526580409
molecular characterization of a reassortant h11n9 subtype avian influenza virus isolated from a domestic duck in eastern china.during surveillance for avian influenza viruses (aivs) in live-poultry markets in eastern china in 2013, an h11n9 aiv was isolated from a domestic duck. phylogenetic analysis showed that this strain received its genes from h11, h3, h10, and h7 aivs of poultry in china. this strain was found to be minimally pathogenic in mice and was able to replicate in mice without prior adaptation. considering that the reassorted h11n9 viruses were isolated from domestic ducks in this study, it is possible tha ...201526212362
[analysis of the genetic evolution of neuraminidases of influenza a subtype n9 viruses].this study analyzed the genetic evolution of neuraminidases (nas) of influenza a subtype n9 viruses with the aim of determining the genetic origin of the novel avian a/h7n9 influenza virus. the na sequences of influenza a subtype n9 viruses available from ncbi were used to construct a phylogenetic tree using the programs clustalx 2.0 and mega 6.0. this analysis indicated that the novel avian a/h7n9 influenza virus is located in the modern eurasian phylogenetic cluster. this cluster was then furt ...201526164938
avian influenza virus (h11n9) in migratory shorebirds wintering in the amazon region, brazil.aquatic birds are the natural reservoir for avian influenza viruses (aiv). habitats in brazil provide stopover and wintering sites for water birds that migrate between north and south america. the current study was conducted to elucidate the possibility of the transport of influenza a viruses by birds that migrate annually between the northern and southern hemispheres. in total, 556 orotracheal/cloacal swab samples were collected for influenza a virus screening using real-time rt-pcr (rrt-pcr). ...201425329399
novel human h7n9 influenza virus in china.outbreaks of h7n9 avian influenza in humans in 5 provinces and 2 municipalities of china have reawakened concern that avian influenza viruses may again cross species barriers to infect the human population and thereby initiate a new influenza pandemic. evolutionary analysis shows that human h7n9 influenza viruses originated from the h9n2, h7n3 and h11n9 avian viruses, and that it is as a novel reassortment influenza virus. this article reviews current knowledge on 11 subtypes of influenza a viru ...201424952971
the zoonotic potential of avian influenza viruses isolated from wild waterfowl in zambia.whilst remarkable progress in elucidating the mechanisms governing interspecies transmission and pathogenicity of highly pathogenic avian influenza viruses (aivs) has been made, similar studies focusing on low-pathogenic aivs isolated from the wild waterfowl reservoir are limited. we previously reported that two aiv strains (subtypes h6n2 and h3n8) isolated from wild waterfowl in zambia harbored some amino acid residues preferentially associated with human influenza virus proteins (so-called hum ...201424862188
little evidence of subclinical avian influenza virus infections among rural villagers in 2008, 800 adults living within rural kampong cham province, cambodia were enrolled in a prospective cohort study of zoonotic influenza transmission. after enrollment, participants were contacted weekly for 24 months to identify acute influenza-like illnesses (ili). follow-up sera were collected at 12 and 24 months. a transmission substudy was also conducted among the family contacts of cohort members reporting ili who were influenza a positive. samples were assessed using serological or molec ...201424819948
long-term variation in influenza a virus prevalence and subtype diversity in migratory mallards in northern 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 a ...201424573857
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