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1.
The outbreak of highly pathogenic avian influenza (HPAI) H5N1 disease has led to significant loss of poultry and wild life and case fatality rates in humans of 60%. Wild birds are natural hosts for all avian influenza virus subtypes and over120 bird species have been reported with evidence of H5N1 infection. Influenza A viruses possess a segmented RNA genome and are characterized by frequently occurring genetic reassortment events, which play a very important role in virus evolution and the spread of novel gene constellations in immunologically naïve human and animal populations. Phylogenetic analysis of whole genome or sub-genomic sequences is a standard means for delineating genetic variation, novel reassortment events, and surveillance to trace the global transmission pathways. In this paper, special emphasis is given to the transmission and circulation of H5N1 among wild life populations, and to the reassortment events that are associated with inter-host transmission of the H5N1 viruses when they infect different hosts, such as birds, pigs and humans. In addition, we review the inter-subtype reassortment of the viral segments encoding inner proteins between the H5N1 viruses and viruses of other subtypes, such as H9N2 and H6N1. Finally, we highlight the usefulness of genomic sequences in molecular epidemiological analysis of HPAI H5N1 and the technical limitations in existing analytical methods that hinder them from playing a greater role in virological research. 相似文献
2.
Genetic characterization of an avian H4N6 influenza virus isolated from the Izumi plain,Japan 下载免费PDF全文
Masakazu Kuwahara Aya Matsuu Tatsunori Masatani Shigehisa Toda Makoto Ozawa 《Microbiology and immunology》2017,61(11):513-518
3.
禽流感病毒最新研究进展 总被引:7,自引:0,他引:7
本文针对2004年爆发的禽流感疫病,回顾了2004年至2005年期间禽流感病毒的研究进展。逆转录聚合酶链式反应技术为禽流感病毒的分型提供了一种快速、可靠、准确的方法。对H5N1禽流感病毒致病机制的研究发现,其强致病性在于它可以躲避人类抗病毒细胞因子的作用,NS1基因编码蛋白的92位谷氨酸在其中发挥了关键作用。由于禽流感疾病多引起结膜炎,并与病毒细胞受体的研究结果相结合,有科学家认为眼部特异性是禽流感病毒的一个总体特征。社会普遍关注禽流感疫苗的研制,人类和禽类流感A型病毒M2蛋白胞外区域的序列比对工作为疫苗研制提供了一条新的思路,依据神经氨酸酶抑制剂抑制病毒的出芽繁殖原理的疫苗正在研制过程中,而利用siRNA预防和治疗禽流感也是很有潜力的一种方法。禽流感病毒研究的另一个热点是病毒基因节段的重配问题。 相似文献
4.
Hans Koblet 《In vitro cellular & developmental biology. Animal》1993,29(4):274-283
Summary Three lines of observation demonstrate the role of arthropods in transmission and evolution of viruses. a) Recent outbreaks
of viruses from their niches took place and insects have played a major role in propagating the viruses. b) Examination of
the list of viral families and their hosts shows that many infect invertebrates (I) and vertebrates (V) or (I) and plants
(P) or all kingdoms (VIPs). This notion holds true irrespective of the genome type. At first glance the argument seems to
be weak in the case of enveloped and non-enveloped RNA viruses with single-stranded (ss) segmented or non-segmented genomes
of positive (+) or negative polarity. Here, there are several families infecting V or P only; no systematic relation to arthropods
is found. c) In the non-enveloped plant viruses with ss RNA genomes there is a strong tendency for segmentation and individual
packaging of the genome pieces. This is in contrast to ss+ RNA animal viruses and can only be explained by massive transmission
by seed or insects or both, because individual packaging necessitates a multihit infection. Comparisons demonstrate relationships
in the nonstructural proteins of double-stranded and ss+ RNA viruses irrespective of host range, segmentation, and envelope.
Similar conclusions apply for the negative-stranded RNA viruses. Thus, viral supergroups can be created that infect V or P
and exploit arthropods for infection or transmission or both. Examples of such relationships and explanations for viral evolution
are reviewed and the arthropod orders important for cell culture are given. 相似文献
5.
Xiaoli Wu Mingyue Li Yanfang Zhang Boyun Liang Junming Shi Yaohui Fang Zhengyuan Su Mengmeng Li Wenjing Zhang Ling Xu Jun Wang Qiaoli Wu Shuang Tang Hualin Wang Tao Zhang Cheng Peng Xin Zheng Fei Deng Shu Shen 《中国病毒学》2021,36(2):300-310
Severe fever with thrombocytopenia syndrome virus(SFTSV), the causative agent of a febrile human disease, was first identified from central and eastern provinces in China, and later in Japan and South Korea. Hubei Province is one of the major SFTS epidemic areas in the central part of China. This study reported the isolation of 11 new SFTSV strains from patients in Hubei Province collected in 2017. Extensive phylogenetic analyses were conducted based on the complete coding sequences of SFTSV segments including the new strains. It was suggested that five different SFTSV genotypes were circulating in Hubei, and 15 reassortment patterns and migration pathways correlated with each genotype were identified, which was more than previously recognized. Hubei Province was more involved in the evolutionary events of SFTSV than that previously thought in which the evolutionary events of SFTSV were reported to be independent from those in other epidemic regions. Further divergence of SFTSV strains was suggested by pairwise comparison of SFTSV sequences from each genotype and sequence identity normalized to representative strain in genotype C1. Subsequently,amino acid variations specific for genotype(s), strain(s), or cluster(s) were inspected, which may be related to differential biological activity of SFTSV strains/genotypes. In conclusion, we analyzed the current status of SFTSV phylogeny in Hubei Province and discussed the possible events correlated to SFTSV evolution. It provided an in-depth insight into SFTSV evolution, raising concerns for the use of proper SFTSV strains in future studies. 相似文献
6.
Reassortant DS‐1‐like G1P[4] Rotavirus A strains generated from co‐circulating strains in Vietnam, 2012/2013 下载免费PDF全文
Chantal Ama Agbemabiese Toyoko Nakagomi Minh Quang Nguyen Punita Gauchan Osamu Nakagomi 《Microbiology and immunology》2017,61(8):328-336
7.
用在地鼠鼻甲繁殖不好、但在肺中繁殖较好的甲/福流/8/58(H2N2)流感病毒,与在地鼠的上下呼吸道均能较好地繁殖的H3N2型病毒重组,所获重组株(福R3),除HA基因是来自H2N2外,其它基因均来自H3N2。该重组病毒像亲本株H2N2株一样,在地鼠鼻甲繁不好。结果表明,编码甲/福流/8/58病毒的H2血凝素的基因影响着地鼠的组织嗜性。 相似文献
8.
ANSON V. KOEHLER JOHN M. PEARCE PAUL L. FLINT J. CHRISTIAN FRANSON HON S. IP 《Molecular ecology》2008,17(21):4754-4762
The role of migratory birds in the movement of the highly pathogenic (HP) avian influenza H5N1 remains a subject of debate. Testing hypotheses regarding intercontinental movement of low pathogenic avian influenza (LPAI) viruses will help evaluate the potential that wild birds could carry Asian-origin strains of HP avian influenza to North America during migration. Previous North American assessments of LPAI genetic variation have found few Asian reassortment events. Here, we present results from whole-genome analyses of LPAI isolates collected in Alaska from the northern pintail (Anas acuta), a species that migrates between North America and Asia. Phylogenetic analyses confirmed the genetic divergence between Asian and North American strains of LPAI, but also suggested inter-continental virus exchange and at a higher frequency than previously documented. In 38 isolates from Alaska, nearly half (44.7%) had at least one gene segment more closely related to Asian than to North American strains of LPAI. Additionally, sequences of several Asian LPAI isolates from GenBank clustered more closely with North American northern pintail isolates than with other Asian origin viruses. Our data support the role of wild birds in the intercontinental transfer of influenza viruses, and reveal a higher degree of transfer in Alaska than elsewhere in North America. 相似文献
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