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1.
禽流感病毒N4亚型神经氨酸酶基因的克隆和序列分析 总被引：1，自引：0，他引：1
应用无特定病原体 (SPF)鸡胚增殖禽流感病毒 A/ Turkey/ Ontario/ 6 118/ 6 8(H8N4 )毒株 ,Tri Zol L S Reagent提取病毒 RNA,RT- PCR扩增神经氨酸酶 (NA)基因全片段 ,克隆到 p MD18- T载体上 ,并进行了鉴定和序列测定。所获得的 NA基因片段长 14 4 1bp,编码 4 90个氨基酸残基。根据推导的氨基酸序列进行预测 ,有 9个潜在的糖基化位点和2 0个半胱氨酸残基 相似文献
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Choi JG Kang HM Kim MC Paek MR Kim HR Kim BS Kwon JH Kim JH Lee YJ 《Veterinary microbiology》2012,155(2-4):147-157
The H3 subtype avian influenza virus (AIV) is one of the most frequently isolated subtypes in domestic ducks, live poultry markets, and wild birds in Korea. In 2002-2009, a total of 45 H3 subtype AIVs were isolated from the feces of clinically normal domestic ducks (n=28) and wild birds (n=17). The most prevalent subtypes in domestic ducks were H3N2 (35.7%), H3N6 (35.7%), H3N8 (25.0%), and H3N1 (3.6%, novel subtype in domestic duck in Korea). In contrast, H3N8 (70.6%) is the most prevalent subtype in wild birds in Korea. In the phylogenetic analysis, HA genes of the Korean H3 AIVs were divided into 3 groups (Korean duck, wild bird 1, and wild bird 2) and all viruses of duck origin except one were clustered in a single group. However, other genes showed extensive diversity and at least 17 genotypes were circulating in domestic ducks in Korea. When the analysis expanded to viruses of wild bird origin, the genetic diversity of Korean H3 AIVs became more complicated. Extensive reassortments may have occurred in H3 subtype influenza viruses in Korea. When we inoculated chickens and ducks with six selected viruses, some of the viruses replicated efficiently without pre-adaptation and shed a significant amount of viruses through oropharyngeal and cloacal routes. This raised concerns that H3 subtype AIV could be a new subtype in chickens in Korea. Continuous surveillance is needed to prepare the advent of a novel subtype AIV in Korea. 相似文献
3.
Cloacal and tracheal swabs were collected from 1389 hunter-killed ducks in Cameron Parish, Louisiana, during the 1986 and 1987 waterfowl seasons. Twenty-eight avian influenza viruses (AIVs) were isolated from 605 blue-winged teal (Anas discors), 75 mottled ducks (A. fulvigula), 375 gadwalls (A. stepera) and 334 green-winged teal (A. crecca). Prevalence estimates of AIV in ducks sampled during September, November, and December through January were 3.1%, 2.0%, and 0.4%, respectively. Differences in prevalence were detected by season (P = 0.044) and age class (P = 0.036). Two isolations from resident mottled ducks document transmission of AIV on these wintering areas. Much subtype diversity was present, with nine of 13 hemagglutinin (HA) and nine of nine neuraminidase (NA) subtypes recovered. Predominant HA and NA subtypes were typical of AIVs commonly associated with waterfowl. Results indicate that AIVs are transmitted in the wintering areas, and, although prevalence is low, these viruses continue to circulate within these duck populations during winter. 相似文献
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Kulak MV Ilinykh FA Zaykovskaya AV Epanchinzeva AV Evstaphiev IL Tovtunec NN Sharshov KA Durimanov AG Penkovskaya NA Shestopalov AM Lerman AI Drozdov IG Swayne DE 《Avian diseases》2010,54(3):1086-1090
The ecology of avian influenza (AI) viruses in wild aquatic birds of Asia is poorly understood, especially for the H5N1 high pathogenicity AI (HPAI) viruses. From March 2006 through November 2008, 20 AI viruses were isolated in the Crimea region of Ukraine with an overall frequency of virus recovery of 3.3%. All the viruses were isolated from three species of dabbling ducks: mallard (Anas platyrhynchos), wigeon (Anas penelope), and garganey (Anas querquedula), making the frequency of virus recovery for dabbling ducks 6.3%. The viruses were predominantly isolated during the fall sampling period. All viruses were genetically and antigenically characterized. No H5N1 HPAI viruses were isolated, but other HA and NA subtypes were identified including H3N1 (2), H3N6 (3), H3N8 (4), H4N6 (6), H5N2 (3), H7N8 (1), and H10N6 (1) subtypes. All isolates were of low pathogenicity, as determined by the intravenous pathogenicity index of 0.00. For H5N2 and H7N8 isolates, the HA gene was sequenced and the phylogenetic analysis revealed possible ecologic connections of the Crimea region with AI viruses from Siberia and Europe. No influenza A isolates were recovered from other Anseriformes (diving ducks [two species of pochards] and graylag geese), Columbiformes (collared doves), Gruiformes (coot), and Galliformes (gray partridges). 相似文献
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Molecular characterization of low pathogenic avian influenza viruses, isolated from food products imported into Singapore 总被引：1，自引：0，他引：1
Dawn Su-Yin Yeo Sock-Hoon Ng Chin-Wen Liaw Ley-Moy Ng Eugene Jing-Hui Wee Elizabeth Ai-Sim Lim Shirely Lay-Kheng Seah Wai-Kwan Wong Chee-Wee Lim Richard J. Sugrue Boon-Huan Tan 《Veterinary microbiology》2009,138(3-4):304-317
We have completed the genetic characterization of all eight gene segments for four low pathogenic avian influenza (LPAI) viruses. The objective of this study was to detect the presence of novel signatures that may serve as early warning indicators of the conversion of LPAI viruses to high pathogenic avian influenza (HPAI) viruses. This study included three H5N2 and one H5N3 viruses that were isolated from live poultry imported into Singapore as part of the national avian influenza virus (AIV) surveillance program. Based on the molecular criterion of the World Organisation for Animal Health (OIE), sequence analysis with the translated amino acid (aa) sequence of the hemagglutinin (HA) gene revealed the absence of multibasic aa at the HA cleavage site, identifying all four virus isolates as LPAI. Detailed phylogenetic tree analyses using the HA and neuraminidase (NA) genes clustered these isolates in the Eurasian H5 lineage, but away from the HPAI H5 subtypes. This analysis further revealed that the internal genes clustered to different avian and swine subtypes, suggesting that the four isolates may possibly share their ancestry with these different influenza subtypes. Our results suggest that the four LPAI isolates in this study contained mainly avian signatures, and the phylogenetic tree for the internal genes further suggests the potential for reassortment with other different circulating avian subtypes. This is the first comprehensive report on the genetic characterization of LPAI H5N2/3 viruses isolated in South-East Asia. 相似文献
8.
为建立简便快速检测禽流感病毒(avian influenza virus,AIV)并同时区分出H9、N2亚型的方法,本试验根据基因库中H9亚型AIV的HA基因、N2亚型AIV的NA基因及AIV的M基因序列,分别设计了3对针对这3种基因保守序列的引物,建立了AIV H9N2亚型的三重PCR检测方法。应用该方法对H9N2亚型AIV模板进行PCR扩增,可得到3条与试验设计相符的目的条带,分别为313 bp (HA基因)、451 bp (NA基因)和667 bp(M基因);对非H9亚型的N2亚型AIV模板进行扩增,出现2条特异性扩增条带,即451 bp (NA基因)和667 bp(M基因);对非H9、N2亚型AIV模板进行扩增则只出现一条目的条带,即667 bp(M基因);对其他禽呼吸道病原体进行PCR扩增,结果均为阴性。敏感性试验结果显示此三重PCR方法最低检出限为10-2 ng/μL。应用所建立的三重PCR方法对120份临床病料进行检测的结果与病毒分离鉴定结果一致。各项试验结果均表明,该方法对于禽流感病毒尤其是H9、N2亚型禽流感病毒的检测具有快捷、特异、灵敏的特点。 相似文献
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Recent developments in avian influenza research: epidemiology and immunoprophylaxis 总被引：10，自引：0，他引：10
Influenza A viruses have been isolated from humans, from several other mammalian species and a wide variety of avian species, among which, wild aquatic birds represent the natural hosts of influenza viruses. The majority of the possible combinations of the 15 haemagglutinin (HA) and nine neuraminidase (NA) subtypes recognized have been identified in isolates from domestic and wild birds. Infection of birds can cause a wide range of clinical signs, which may vary according to the host, the virus strain, the host's immune status, the presence of any secondary exacerbating microorganisms and environmental factors. Most infections are inapparent, especially in waterfowl and other wild birds. In contrast, infections caused by viruses of H5 and H7 subtypes can be responsible for devastating epidemics in poultry. Despite the warnings to the poultry industry about these viruses, in 1997 an avian H5N1 influenza virus was directly transmitted from birds to humans in Hong Kong and resulted in 18 confirmed infections, thus strengthening the pandemic threat posed by avian influenza (AI). Indeed, reassortant viruses, harbouring a combination of avian and human viral genomes, have been responsible for major pandemics of human influenza. These considerations warrant the need to continue and broaden efforts in the surveillance of AI. Control programmes have varied from no intervention, as in the case of the occurrence of low pathogenic (LP) AI (LPAI) viruses, to extreme, expensive total quarantine-slaughter programmes carried out to eradicate highly pathogenic (HP) AI (HPAI) viruses. The adoption of a vaccination policy, targeted either to control or to prevent infection in poultry, is generally banned or discouraged. Nevertheless, the need to boost eradication efforts in order to limit further spread of infection and avoid heavy economic losses, and advances in modern vaccine technologies, have prompted a re-evaluation of the potential use of vaccination in poultry as an additional tool in comprehensive disease control strategies. This review presents a synthesis of the most recent research on AI that has contributed to a better understanding of the ecology of the virus and to the development of safe and efficacious vaccines for poultry. 相似文献
10.
《Veterinary microbiology》2015,175(2-4):356-361
Highly pathogenic avian influenza A(HPAI) H5N1 viruses pose a serious pandemic threat due to their virulence and high mortality in humans, and their increasingly expanding host range and significant ongoing evolution could enhance their human-to-human transmissibility. Recently, various reassortant viruses were detected in different domestic poultry, with the HA gene derived from the A/goose/Guangdong/1/96-like (Gs/GD-like) lineage and the NA gene from influenza viruses of other subtypes. It is reported that some natural reassortant H5N5 highly pathogenic avian influenza viruses were isolated from poultry in China. And their HA genes were belonged to a new clade 2.3.4.4. We evaluated the receptor binding property and transmissibility in guinea pigs of these reassortant H5N5 HPAIVs. The results showed that these viruses bound to both avian-type (α-2,3) and human-type (α-2,6) receptors. In addition, we found that one of these viruses, 031, not only replicated but also transmitted efficiently in guinea pigs. Therefore, such reassortant influenza viruses may pose a pandemic threat. 相似文献
11.
为建立一种同时检测H4、N2和所有亚型禽流感的方法,分别针对H4亚型禽流感病毒(AIV)HA基因、N2亚型AIV NA基因和所有亚型AIV M基因保守序列,设计筛选出3对特异性引物,优化引物之间的浓度,对三重反应体系进行特异性和敏感性验证,建立了H4、N2和所有亚型AIV三重RT-PCR检测方法,并用该法对临床样品进行检测。建立的方法能特异性扩增H4、N2和所有亚型AIV,与其他禽病病原体不发生交叉反应;对H4、N2和所有亚型AIV至少能检测到6 pg/μL。在185份临床样品的检测中,检出4份H4、10份N2和19份AIV阳性。所建立的三重RT-PCR方法特异性强、灵敏度高,为快速检测H4、N2和所有亚型AIV提供了有效的方法。 相似文献
12.
2009年在我国南方活禽交易市场进行流行病学调查时,从鸭体内分离到2株H4N3亚型禽流感病毒(AIV),DK/FJ/S1419/09(H4N3)(FJ/419/2009)和DK/HUN/S1010/09(H4N3)(HuN/010/2009)。为了解这2株H4N3亚型AIV的生物学特性,本研究对其进行全基因组分析及对小鼠致病性研究。结果显示:其HA基因来源于近两年流行的H4亚型病毒株,NA基因来源于其它亚型病毒株。内部基因来源较复杂,与FJ/419/2009内部基因同源性最高的病毒株均来自国内H5、H6等亚型分离株,但与HuN/010/2009同源的内部基因则差异较大,与PA、M和NS同源性最高的病毒株分别为A/wild/duck/Korea/UP122/2007(H1N1),A/muscovy/duck/Thailand/CU-LM1983/2009(H4N6)and A/avian/Japan 8KI0068/2008(H3N6)。用106EID50病毒剂量感染6周龄BALB/c小鼠,结果显示试验组小鼠感染后第3 d采脏器样品,仅在鼻甲和肺部能检测到病毒存在。以上数据表明,尽管这2株H4N3特殊亚型组合病毒来源复杂,但对小鼠的致病性较低。 相似文献
13.
Ramp K Veits J Deckers D Rudolf M Grund C Mettenleiter TC Römer-Oberdörfer A 《Avian diseases》2011,55(3):413-421
To analyze the contribution of neuraminidase (NA) toward protection against avian influenza virus (AIV) infection, three different recombinant Newcastle disease viruses (NDVs) expressing hemagglutinin (HA) or NA, or both, of highly pathogenic avian influenza virus (HPAIV) were generated. The lentogenic NDV Clone 30 was used as backbone for the insertion of HA of HPAIV strain A/chicken/Vietnam/P41/05 (H5N1) and NA of HPAIV strain A/duck/Vietnam/TG24-01/05 (H5N1). The HA was inserted between the genes encoding NDV phosphoprotein (P) and matrixprotein (M), and the NA was inserted between the fusion (F) and hemagglutinin-neuraminidase protein (HN) genes, resulting in NDVH5VmPMN1FHN. Two additional recombinants were constructed carrying the HA gene between the NDV P and M genes (NDVH5VmPM) or the NA between F and HN (NDVN1FHN). All recombinants replicated well and stably expressed the HA gene, the NA gene, or both. Chickens immunized with NDVH5VmPMN1FHN or NDVH5VmPM were protected against two different HPAIV H5N1 and also against HPAIV H5N2. In contrast, immunization of chickens with NDVN1FHN induced NDV- and AIV N1-specific antibodies but did not protect the animals against a lethal dose of HPAIV H5N1. Furthermore, expression of AIV N1, in addition to AIV H5 by NDV, did not increase protection against HPAIV H5N1. 相似文献
14.
为了对供港猪群中的猪流感流行情况进行分析,从华南地区供港猪群中用无菌棉拭子采集鼻腔粘液样品,采用鸡胚接种方法,从供港猪群中分离出了2株不同亚型的猪流感病毒株,经国家流感中心鉴定分别为H1N1和H3N2亚型。本研究设计了猪流感常见亚型的HA和NA分型特异性引物,建立了猪流感型特异性RT-PCR检测方法;对分离鉴定的2株猪流感病毒和禽流感H5N1 HI检测抗原进行了RT-PCR检测,并对其部分HA和NA基因进行克隆测序分析。对供港猪群的血清检测结果表明:供港猪群中H1N1和H3N2亚型抗体阳性率分别为26.87%、38.26%,禽流感H5N1和H9N2亚型抗体阳性率均为0%。 相似文献
15.
为了解鸭源H6N2亚型禽流感病毒(AIV)的生物学特性,本研究对两株鸭源H6N2亚型AIV [A/duck/Hube/Sd061/2008(HB/061/08)和A/duck/Fujian/S2080/2009(FJ/080/09)]进行序列分析和致病性试验.序列分析显示:两株病毒的HA和NA基因均来源于我国近年流行的H6亚型病毒株,但是HB/061/08株的内部基因可能来源于H9、H5等其他亚型.与病毒株HB/061/08 NP、PA、PB2基因的核苷酸同源性最高的病毒株为A/environment/Hunan/2-84/2007(H9N2);与M、PB1和NS基因的核苷酸同源性最高的病毒株分别为A/duck/Zhejiang/11/2000(H5N1)、A/chicken/Hebei/7/2008(H9N2)和A/chicken/Henan/L1/2008(H9N2).两株病毒的抗原差异性较显著,相关系数为0.49;用106 EID50病毒剂量感染4周龄SPF鸡,结果显示FJ/080/09株不能感染鸡,而HB/061/08株在鸡体内能够高效复制,并通过咽喉和泄殖腔持续排毒.鸡群感染后第3d采取脏器样品,在气管和肺部能够检测到病毒存在,部分脏器和器官的组织学观察显示存在一定程度的病理变化.以上数据表明,H6亚型AIV在跨越不同宿主感染的传播过程中,对新宿主适应能力的差异导致对其致病性的差异. 相似文献
16.
Avian influenza virus (AIV) is enzootic to wild birds, which are its natural reservoir. The virus exhibits a large degree of genetic diversity and most of the isolated strains are of low pathogenicity to poultry. Although AIV is nearly ubiquitous in wild bird populations, highly pathogenic H5N1 subtypes in poultry have been the focus of most modeling efforts. To better understand viral ecology of AIV, a predictive model should 1) include wild birds, 2) include all isolated subtypes, and 3) cover the host’s natural range, unbounded by artificial country borders. As of this writing, there are few large-scale predictive models of AIV in wild birds. We used the Random Forests algorithm, an ensemble data-mining machine-learning method, to develop a global-scale predictive map of AIV, identify important predictors, and describe the environmental niche of AIV in wild bird populations. The model has an accuracy of 0.79 and identified northern areas as having the highest relative predicted risk of outbreak. The primary niche was described as regions of low annual rainfall and low temperatures. This study is the first global-scale model of low-pathogenicity avian influenza in wild birds and underscores the importance of largely unstudied northern regions in the persistence of AIV. 相似文献
17.
Simultaneous detection and differentiation of Newcastle disease and avian influenza viruses using oligonucleotide microarrays 总被引：2，自引：0，他引：2
Wang LC Pan CH Severinghaus LL Liu LY Chen CT Pu CE Huang D Lir JT Chin SC Cheng MC Lee SH Wang CH 《Veterinary microbiology》2008,127(3-4):217-226
Newcastle disease (ND) and avian influenza (AI) are two of the most important zoonotic viral diseases of birds throughout the world. These two viruses often have a great impact upon the poultry industry. Both viruses are associated with transmission from wild to domestic birds, and often display similar signs that need to be differentiated. A rapid surveillance among wild and domestic birds is important for early disease detection and intervention, and is the basis for what measures should be taken. The surveillance, thus, should be able to differentiate the diseases and provide a detailed analysis of the virus strains. Here, we described a fast, simultaneous and inexpensive approach to the detection of Newcastle disease virus (NDV) and avian influenza virus (AIV) using oligonucleotide microarrays. The NDV pathotypes and the AIV haemagglutinin subtypes H5 and H7 were determined at the same time. Different probes on a microarray targeting the same gene were implemented in order to encompass the diversified virus strains or provide multiple confirmations of the genotype. This ensures good sensitivity and specificity among divergent viruses. Twenty-four virus isolates and twenty-four various combinations of the viruses were tested in this study. All viruses were successfully detected and typed. The hybridization results on microarrays were clearly identified with the naked eyes, with no further imaging equipment needed. The results demonstrate that the detection and typing of multiple viruses can be performed simultaneously and easily using oligonucleotide microarrays. The proposed method may provide potential for rapid surveillance and differential diagnosis of these two important zoonoses in both wild and domestic birds. 相似文献
18.
Influenza viruses in birds of the Atlantic flyway. 总被引：2，自引：0，他引：2
I L Graves 《Avian diseases》1992,36(1):1-10
Isolation of type A influenza viruses from the feces of 5013 birds of 16 species was attempted during a 33-month study (1977-79). Seventy viruses were isolated from the feces of 3403 ring-billed gulls in Baltimore, Md., during 16 months of sampling. Six hemagglutinin (HA) subtypes and seven neuraminidase (NA) subtypes in 15 combinations were found. The H13N6 virus was the only subtype found each year and accounted for 40% of the isolates. The rate of isolation from gulls was 0.26% in the cold months and 3.0% in the warm months. Hemagglutination-inhibition (HI) and elution-inhibition antibody profiles reflected the presence of some but not all of the viruses isolated. In mute swans, the rates of seroconversions were 16% for HA antibody and 14% for NA antibody, whereas the viral isolation rate was 0.4% over a 3-year period. Both the H5 and the N2 subtypes, which were responsible for the lethal chicken outbreaks in 1983 in Pennsylvania, were isolated from gulls in 1978 in association with subtypes not found in the chicken virus. Also, seroconversions for the H5 HA occurred in mute swans in 1978. 相似文献
19.
从湖南分离得到一株H5N1亚型禽流感病毒(AIV),首先设计合成两对HA和NA基因特异性引物,采用两步法RT-PCR,对鸭流感病毒株 A/Duck/HunanWugang/2/2004(H5N1)(简称DK/HNWG/2/04)的表面蛋白基因进行序列测定,并与国内外已经发表的H5N1亚型毒株表面蛋白基因进行序列分析和比较.结果表明,HA和NA基因全长分别约为1.7 kb和1.4 kb,分离株与14个参考毒株HA基因的同源性为95.9%～98.0%,NA基因的同源性为87.0%～98.4%.根据HA基因核苷酸序列推导HA裂解位点氨基酸,发现分离株的裂解位点包含多个碱性氨基酸,符合高致病性禽流感的特征. 相似文献
20.
Ebrahim Kord Amir Kaffashi Hadi Ghadakchi Fatemeh Eshratabadi Zakaria Bameri Abdelhamed Shoushtari 《Tropical animal health and production》2014,46(3):549-554
Highly pathogenic avian influenza (HPAI) H5N1 virus is causing the death of a large number of wild birds and poultry. HPAI H5N1 was reported in the north of Iran in 2011. In this study, two A/Chicken/Iran/271/2011 and A/Duck/Iran/178/2011 viruses were genetically characterized by sequence analysis of Hemagglutinin (HA) and Neuraminidase (NA) genes. Phylogenetic analysis revealed that these viruses were different from previous Iranian isolates (Clade 2.2) and belonged to the subclade 2.3.2.1. The results showed that the detected viruses are almost identical to each other and closely related to HPAI H5N1 strains isolated in Mongolia in 2010. Based on the amino acid sequence analysis, these viruses at their HA cleavage sites contained the multibasic amino acid motif PQRERRRK-R/GLF lacking a lysine residue compared with the previous reports of the same motif. There is also a 20-amino acid deletion (resides 49–69) in the NA stalk similar to other viruses isolated after 2000. It seems that introduction of HPAI H5N1 to Iran might have happened by wild birds from Mongolian origin virus. 相似文献