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正A型流感病毒是引起人和动物流感的主要病原,对人类的生命健康和社会生活形成巨大威胁。A型流感病毒亚类较多,感染宿主较广,且可以跨种传播进而造成流感大流行,因此A型流感病毒的跨种传播机制一直是本领域的研究热点。流感病毒的RNA聚合酶是该病毒在宿主细胞内转录与复制的物质基础,在病毒的跨物种传播中发挥重要作用。其需借助某些宿主蛋白来完成病毒的转录和复制过程,目前已经发现有多种宿主因子 相似文献
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小鼠模型在不同亚型流感病毒致病性及跨种传播研究中的应用 总被引：1，自引：0，他引：1
A型流感病毒是目前传播最广泛的人畜共患病病原之一,到目前为止全球至少暴发了5次人流感大流行,尤其是1997年以来多起H5N1亚型高致病性禽流感病毒跨越种间屏障由禽直接感染并致死人的事件造成了极大恐慌。流感病毒致病性和跨种传播的分子机制研究是有效预防和控制流感的基础,而BALB/c小鼠模型的应用极大地促进了这些研究进程,作者就BALB/c小鼠作为试验动物模型在流感病毒致病性及跨种传播研究中的应用作一综述。 相似文献
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禽流感（avian influenza,AI）是由A型流感病毒引起的家禽或野禽的疾病综合征。根据禽流感病毒（AIV）的致病力通常分为高致病性禽流感（HPAI）和低致病性禽流感（MPAI）,HPAI传播快,具有高度致死性;MPAI多呈隐性感染或症状较轻,不导致严重病变或死亡。AI历来被认为是人类流感的最大基因库,是人流感病毒发生变异的新基因来源。1997年,中国香港H5N1 AIV及1999年中国大陆和香港H9N2AIV首次突破种间障碍直接感染人甚至致死。不但打破了自然条件下仅有H1、H2和H3亚型流感病毒可以感染人和其他哺乳动物的常规,而且为人流感增添了新的毒株亚型（H5和H9）。由此赋予了AIV（禽流感病毒）全新的公共卫生意义。 相似文献
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流感病毒受体识别以及流感病毒跨宿主感染的分子机理 总被引：4，自引：0，他引：4
近年来禽流感病毒在亚洲流行,使家禽养殖业受到很大冲击。令人担心的是,从东南亚疫情爆发地区还报道了人类感染禽流感病毒的病例,我国湖南等省也有人类感染禽流感病毒。目前疫情虽然已经得到控制,但是H5N1亚型禽流感病毒将长期在亚洲存在。由于流感病毒的自身基因组极易产生变异和亚洲地区家禽业的养殖模式特点,禽流感病毒极有可能进化成可以跨宿主感染的新型流感毒株。本文对流感病毒的受体识别和跨宿主感染的分子机理作一综述,并讨论若出现流感大流行时的药物控制措施。 相似文献
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H9N2型禽流感病毒不同传播方式的分子机制 总被引：2，自引：0，他引：2
H 9N 2亚型禽流感病毒属正黏病毒科流感病毒属A型流感病毒。虽表现低致病性,但由于传播广泛、能造成免疫抑制并使宿主易发生继发感染,其危害不容忽视[1]。反向遗传技术是近几年快速发展的一项新方法,是根据病毒基因组及其复制的特点,建立操作系统,从克隆的cDNA产生病毒的过程[2 相似文献
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提高警惕,严防流感病毒“兴风作浪”——猪流感的严重危害和公共卫生意义 总被引：2，自引：1，他引：1
由于猪的呼吸道上皮细胞具有人流感病毒和禽流感病毒的受体,因此猪是禽、猪、人流感病毒共同的易感宿主,是流感病毒通过基因重组产生新流行毒株的＂混合器＂和古老的流感病毒长期存在的＂贮存器＂。流感病毒有八个基因片段,猪流感病毒与人流感病毒、禽流感病毒同时感染一个细胞的时候,病毒在自我复制的过程中就会发生基因交换,重组形成新的病毒。根据美国疾控中心的检测,2009年4月引起墨西哥、美国等国人流感爆发的墨西哥A/H1N1型流感病毒毒株是一种新型变异病毒,是人类流感病毒、北美洲禽流感病毒以及北美洲、欧洲和亚洲猪流感病毒的混合体。猪流感病毒（H1N1,H3N2）在中国猪群中普遍存在,而且H9N2和H5N1禽流感病毒也感染了猪,这已经是不争的事实,但这次病毒暴发在北美,而且是在人中间的暴发,因此现在需要重视的是人之间的传播,严密监控这种病毒是否入境;同时长远来看,应该对中国的猪群进行排查,预警可能发生的疫情。 相似文献
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给全球养殖禽类及产业造成巨大损失的高致病性禽流感病毒,是一种可以导致死亡的疾病。在近三十年当中,这种高致病性禽流感病毒在非洲,中国,欧洲,东南亚等地相当流行,已经形成了一定的流感区域,对当地造成相当大的威胁。虽然目前这种病毒并没有在人际之间发生传播,但是这种病毒若于人流感病毒进行新的重组,就将成为人间传播可致死的流感病毒,这会形成新的流感盛行。人类感染禽流感的主要途径分别是通过直接接触了带有禽流感病毒的禽类或者接触了含有禽流感病毒的排泄物。在经过不断变异后的禽流感很有可能冲破种属屏障,从而将危机到人类和哺乳类动物,从而在宿主和病毒等多种因素的作用下使宿主发病升至死亡。目前研究出其致病机制,并对其进行防治非常关键。 相似文献
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给全球养殖禽类及产业造成巨大损失的高致病性禽流感病毒，是一种可以导致死亡的疾病。在近三十年当中，这种高致病性禽流感病毒在非洲，中国，欧洲，东南亚等地相当流行，已经形成了一定的流感区域，对当地造成相当大的威胁。虽然目前这种病毒并没有在人际之间发生传播，但是这种病毒若于人流感病毒进行新的重组，就将成为人间传播可致死的流感病毒，这会形成新的流感盛行。人类感染禽流感的主要途径分别是通过直接接触了带有禽流感病毒的禽类或者接触了含有禽流感病毒的排泄物。在经过不断变异后的禽流感很有可能冲破种属屏障，从而将危机到人类和哺乳类动物，从而在宿主和病毒等多种因素的作用下使宿主发病升至死亡。目前研究出其致病机制，并对其进行防治非常关键。 相似文献
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（接上期）A型流感病毒及禽流感对人的感染1 概述 流感自古以来就是动物与人共患的急性高度传染性疾病。流感病毒属正黏病毒科的病毒，根据病毒核蛋白抗原的特点可分为A、B、C三型，而A型除感染动物外，还可感染人类。A型流感病毒目前已明确有15个HA（血凝素）亚型和9个NA（神经氨酸苷酶）亚型，每个A型流感毒株只有1个HA亚型和1个NA亚型组合。2 A型流感病毒的宿主及其对人的感染情况（见表1）3 哺乳动物和人感染禽流感病毒情况3．1 猪：由于猪的流感在其体内具有禽流感病毒和人流感病毒，因此，通常都把猪作为A型流感病毒的“中间宿… 相似文献
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H9N2亚型禽流感病毒已在世界范围内的禽类中分离确认,并被证实可以传播到人类和低等哺乳类动物。对于它存在的潜在危害已经越来越多地受到关注,相关的研究也相继开展。许多遗传进化的分析为禽或猪流感可以直接感染人提供了证据,通过在人体的适应或与人流感病毒基因重组,可以形成新的病毒株,引起人类流感疫情暴发。文章提示应当密切监控H9N2亚型禽流感病毒,防止人类流感大流行。 相似文献
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Avian influenza viruses do not typically replicate efficiently in humans, indicating direct transmission of avian influenza virus to humans is unlikely. However, since 1997, several cases of human infections with different subtypes (H5N1, H7N7, and H9N2) of avian influenza viruses have been identified and raised the pandemic potential of avian influenza virus in humans. Although circumstantial evidence of human to human transmission exists, the novel avian-origin influenza viruses isolated from humans lack the ability to transmit efficiently from person-to-person. However, the on-going human infection with avian-origin H5N1 viruses increases the likelihood of the generation of human-adapted avian influenza virus with pandemic potential. Thus, a better understanding of the biological and genetic basis of host restriction of influenza viruses is a critical factor in determining whether the introduction of a novel influenza virus into the human population will result in a pandemic. In this article, we review current knowledge of type A influenza virus in which all avian influenza viruses are categorized. 相似文献
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Chengmin WANG Jing LUO Jing WANG Wen SU Shanshan GAO Min ZHANG Li XIE Hua DING Shelan LIU Xiaodong LIU Yu CHEN Yaxiong JIA Hongxuan HE 《Integrative zoology》2014,9(3):372-375
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 virus from human which can cause human infections. 相似文献
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Aunyaratana Thontiravong Suwarak Wannaratana Rachod Tantilertcharoen Duangduean Prakairungnamthip Ranida Tuanudom Jiroj Sasipreeyajan Somsak Pakpinyo Alongkorn Amonsin Pravina Kitikoon Kanisak Oraveerakul 《Journal of veterinary science (Suw?n-si, Korea)》2012,13(4):395-403
Quail has been proposed to be an intermediate host of influenza A viruses. However, information on the susceptibility and pathogenicity of pandemic H1N1 2009 (pH1N1) and swine influenza viruses in quails is limited. In this study, the pathogenicity, virus shedding, and transmission characteristics of pH1N1, swine H1N1 (swH1N1), and avian H3N2 (dkH3N2) influenza viruses in quails was examined. Three groups of 15 quails were inoculated with each virus and evaluated for clinical signs, virus shedding and transmission, pathological changes, and serological responses. None of the 75 inoculated (n = 45), contact exposed (n = 15), or negative control (n = 15) quails developed any clinical signs. In contrast to the low virus shedding titers observed from the swH1N1-inoculated quails, birds inoculated with dkH3N2 and pH1N1 shed relatively high titers of virus predominantly from the respiratory tract until 5 and 7 DPI, respectively, that were rarely transmitted to the contact quails. Gross and histopathological lesions were observed in the respiratory and intestinal tracts of quail inoculated with either pH1N1 or dkH3N2, indicating that these viruses were more pathogenic than swH1N1. Sero-conversions were detected 7 DPI in two out of five pH1N1-inoculated quails, three out of five quails inoculated with swH1N1, and four out of five swH1N1-infected contact birds. Taken together, this study demonstrated that quails were more susceptible to infection with pH1N1 and dkH3N2 than swH1N1. 相似文献
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旨在了解河南省猪流感病毒的流行情况及其遗传进化和基因组特征。2018年4月，从河南省某一出现疑似流感症状猪群中采集鼻拭子样品150份用于分离病毒，对分离病毒的全基因组进行序列测定和分析。同时感染6周龄BALB/c小鼠，研究其对小鼠的致病性。结果显示，获得1株H1N1亚型病毒[命名为A/swine/Henan/NY20/2018（H1N1）]。遗传进化表明，其HA和NA基因属于欧亚类禽H1N1分支，PB2、PB1、PA、NP和M基因属于2009甲型H1N1分支，NS基因属于经典H1N1分支。HA蛋白的裂解位点序列为PSIQSR↓GL，具有低致病性流感病毒的分子特征，在小鼠肺和鼻甲有效复制并能引起肺组织病理学变化。本研究分离到1株3源重排H1N1亚型病毒，对小鼠呈现一定致病力，提示应进一步加强对SIV的监测。 相似文献
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Núria Busquets Joaquim Segalés Lorena Córdoba Tufaria Mussá Elisa Crisci Gerard E. Martín-Valls Meritxell Simon-Grifé Marta Pérez-Simó Monica Pérez-Maíllo Jose I. Nú?ez Francesc X. Abad Lorenzo Fraile Sonia Pina Natalia Majó Albert Bensaid Mariano Domingo María Montoya 《Veterinary research》2010,41(5)
The recent pandemic caused by human influenza virus A(H1N1) 2009 contains ancestral gene segments from North American and Eurasian swine lineages as well as from avian and human influenza lineages. The emergence of this A(H1N1) 2009 poses a potential global threat for human health and the fact that it can infect other species, like pigs, favours a possible encounter with other influenza viruses circulating in swine herds. In Europe, H1N1, H1N2 and H3N2 subtypes of swine influenza virus currently have a high prevalence in commercial farms. To better assess the risk posed by the A(H1N1) 2009 in the actual situation of swine farms, we sought to analyze whether a previous infection with a circulating European avian-like swine A/Swine/Spain/53207/2004 (H1N1) influenza virus (hereafter referred to as SwH1N1) generated or not cross-protective immunity against a subsequent infection with the new human pandemic A/Catalonia/63/2009 (H1N1) influenza virus (hereafter referred to as pH1N1) 21 days apart. Pigs infected only with pH1N1 had mild to moderate pathological findings, consisting on broncho-interstitial pneumonia. However, pigs inoculated with SwH1N1 virus and subsequently infected with pH1N1 had very mild lung lesions, apparently attributed to the remaining lesions caused by SwH1N1 infection. These later pigs also exhibited boosted levels of specific antibodies. Finally, animals firstly infected with SwH1N1 virus and latter infected with pH1N1 exhibited undetectable viral RNA load in nasal swabs and lungs after challenge with pH1N1, indicating a cross-protective effect between both strains. 相似文献
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H5-H7双价禽流感核酸疫苗免疫研究 总被引：2，自引：0，他引：2
由于禽流感的高度变异性,免疫后不同亚型之间难以得到交叉保护,以致病毒得以逃避宿主免疫系统的监视,多价核酸禽流感疫苗具有可以保护不同亚型病毒攻击的特点。本试验设计并构建了包含禽流感H5HA和H7HA1基因的双价真核表达质粒pV-H5-H7及单独表达H5HA和H7HA1的pV-H5和pV-H7HA1。通过RT-PCR,间接免疫荧光(IFA)等方法验证构建质粒的正确性和其表达蛋白的免疫原性。0,21 d分别免疫6~8周龄的BALB/c小鼠,设立双价疫苗组,单表达免疫组和对照组。免疫后35 d用HPAIV H5N1进行致死性攻击。结果显示免疫组均可刺激机体产生H5特异性抗体,pV-H5-H7诱导产生的抗体对H5N1的攻毒保护率为80%,而pV-H5单表达的攻毒保护率也为80%。表明本实验构建的双价禽流感核酸疫苗的免疫效果与单表达组相当(P>0.05),为多价禽流感核酸疫苗的研制提供了基础。 相似文献
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Zoonotic agents challenging the world every year afresh are influenza A viruses. In the past, human pandemics caused by influenza A viruses had been occurring periodically. Wild aquatic birds are carriers of the full variety of influenza virus A subtypes, and thus, most probably constitute the natural reservoir of all influenza A viruses. Whereas avian influenza viruses in their natural avian reservoir are generally of low pathogenicity (LPAIV), some have gained virulence by mutation after transmission and adaptation to susceptible gallinaceous poultry. Those so-called highly pathogenic avian influenza viruses (HPAIV) then cause mass die-offs in susceptible birds and lead to tremendous economical losses when poultry is affected. Besides a number of avian influenza virus subtypes that have sporadically infected mammals, the HPAIV H5N1 Asia shows strong zoonotic characteristics and it was transmitted from birds to different mammalian species including humans. Theoretically, pandemic viruses might derive directly from avian influenza viruses or arise after genetic reassortment between viruses of avian and mammalian origin. So far, HPAIV H5N1 already meets two conditions for a pandemic virus: as a new subtype it has been hitherto unseen in the human population and it has infected at least 438 people, and caused severe illness and high lethality in 262 humans to date (August 2009). The acquisition of efficient human-to-human transmission would complete the emergence of a new pandemic virus. Therefore, fighting H5N1 at its source is the prerequisite to reduce pandemic risks posed by this virus. Other influenza viruses regarded as pandemic candidates derive from subtypes H2, H7, and H9 all of which have infected humans in the past. Here, we will give a comprehensive overview on avian influenza viruses in concern to their zoonotic potential. 相似文献
19.
Van Reeth K 《Veterinary research》2007,38(2):243-260
The introduction of swine or avian influenza (AI) viruses in the human population can set the stage for a pandemic, and many fear that the Asian H5N1 AI virus will become the next pandemic virus. This article first compares the pathogenesis of avian, swine and human influenza viruses in their natural hosts. The major aim was to evaluate the zoonotic potential of swine and avian viruses, and the possible role of pigs in the transmission of AI viruses to humans. Cross-species transfers of swine and avian influenza to humans have been documented on several occasions, but all these viruses lacked the critical capacity to spread from human-to-human. The extreme virulence of H5N1 in humans has been associated with excessive virus replication in the lungs and a prolonged overproduction of cytokines by the host, but there remain many questions about the exact viral cell and tissue tropism. Though pigs are susceptible to several AI subtypes, including H5N1, there is clearly a serious barrier to infection of pigs with such viruses. AI viruses frequently undergo reassortment in pigs, but there is no proof for a role of pigs in the generation of the 1957 or 1968 pandemic reassortants, or in the transmission of H5N1 or other wholly avian viruses to humans. The major conclusion is that cross-species transmission of influenza viruses per se is insufficient to start a human influenza pandemic and that animal influenza viruses must undergo dramatic but largely unknown genetic changes to become established in the human population. 相似文献
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2013年2月以来,华东地区被一场突如其来的＂疫情＂笼罩,后确诊为人感染H7N9禽流感病毒。由于被冠以“H7N9禽流感”,致使全国养禽业损失惨重。截至2013年上半年,受H7N9流感疫情影响,在短短3个月的时间内,养殖场户直接经济损失超过600亿元。最近,世界卫生组织（WHO）、世界动物卫生组织（OIE）和联合国粮农组织（FAO）等三家国际组织专家就“H7N9禽流感”名称会商,建议媒体使用“H7N9流感”或“H7N9病毒”的名称,这样更客观、准确。文章提出,对待类似情况,一定要本着科学、严谨的态度,不要因为人为的原因,造成不必要的损失,增加疾病控制的难度。 相似文献