The evolution of H5N1 influenza viruses in ducks in southern China
The evolution of H5N1 influenza viruses in ducks in southern China
复制标题
DOI：
10.1073/pnas.0403212101
复制
发表时间：
2004-07-13
影响因子：
11.1
通讯作者：
Yu, K
中科院分区：
文献类型：
--
作者：
Chen, H;Deng, G;Yu, K
自1980年代中期以来，禽H5 N1流感病毒对哺乳动物的致病性一直在演变。在这里，我们证明，H5 N1流感病毒，分离自中国大陆的健康家鸭从1999年至2002年，逐渐成为更具致病性的哺乳动物，我们提出了一个假设，解释这种进化方向的机制。从1999年至2002年从中国南方健康鸭群中分离的21株病毒被证实为H5 N1亚型A型流感病毒。这些分离株的抗原性类似于A/Goose/Guangdong/1/96（H5 N1）病毒，该病毒是1997年香港“禽流感”血凝素基因的来源，并且都对鸡具有高致病性。这些病毒根据其在小鼠中的复制和致死性形成四种病理型。在哺乳动物模型中，这些分离株的致病性逐渐增加，存在明显的时间模式。六个H5 N1病毒分离株中有五个在接种的鸭中复制，并从气管或泄殖腔脱落，但没有引起疾病症状或死亡。全基因组系统发育分析表明，绝大多数病毒是含有A/Goose/Guangdong/1/ 96-like hernagglutinin基因和其它未知欧亚禽流感病毒基因的同源毒株。本研究是对最近在中国大陆鸭群中流行的H5 N1禽流感病毒的一种鉴定。我们的研究结果表明，需要立即采取行动，以防止高致病性禽流感病毒从表面上健康的鸭子传播到鸡或哺乳动物宿主。
The pathogenicity of avian H5N1 influenza viruses to mammals has been evolving since the mid-1980s. Here, we demonstrate that H5N1 influenza viruses, isolated from apparently healthy domestic ducks in mainland China from 1999 through 2002, were becoming progressively more pathogenic for mammals, and we present a hypothesis explaining the mechanism of this evolutionary direction. Twenty-one viruses isolated from apparently healthy ducks in southern China from 1999 through 2002 were confirmed to be H5N1 subtype influenza A viruses. These isolates are antigenically similar to A/Goose/Guangdong/l/96 (H5N1) virus, which was the source of the 1997 Hong Kong "bird flu" hemagglutinin gene, and all are highly pathogenic in chickens. The viruses form four pathotypes on the basis of their replication and lethality in mice. There is a clear temporal pattern in the progressively increasing pathogenicity of these isolates in the mammalian model. Five of six H5N1 isolates tested replicated in inoculated ducks and were shed from trachea or cloaca, but none caused disease signs or death. Phylogenetic analysis of the full genome indicated that most of the viruses are reassortants containing the A/Goose/Guangdong/l/ 96-like hernagglutinin gene and the other genes from unknown Eurasian avian influenza viruses. This study is a characterization of the H5N1 avian influenza viruses recently circulating in ducks in mainland China. Our findings suggest that immediate action is needed to prevent the transmission of highly pathogenic avian influenza viruses from the apparently healthy ducks into chickens or mammalian hosts.