Phylogenetic tracing and biological characterization of a novel clade 2.3.2.1 reassortant of H5N6 subtype avian influenza virus in China
Phylogenetic tracing and biological characterization of a novel clade 2.3.2.1 reassortant of H5N6 subtype avian influenza virus in China
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中国H5N6亚型禽流感病毒新进化枝2.3.2.1重配体的系统发育追踪和生物学特性
DOI：
10.1111/tbed.13736
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发表时间：
2020-08-04
影响因子：
4.3
通讯作者：
Liu, Xiufan
中科院分区：
文献类型：
--
作者：
Ge, Zhichuang;Gu, Min;Liu, Xiufan
近年来，H5 N6亚型和H5 N1亚型高致病性禽流感病毒在我国逐渐流行，两者的共传播必然促进彼此间的基因重组。2.3.2.1 2.3.4.4在2017-2018年对中国东部活禽市场（LPMs）的常规监测期间，从表面健康的鸭子的泄殖腔拭子中分离出一种具有来自进化枝2.3.2.1的HA基因的新型H5 N6毒株。系统进化树分析表明，另外两个具有不同PB 1基因谱系的进化枝2.3.2.1 H5 N1株和一2.3.4.4具有时空接近优势基因型的进化枝www.example.com H5 N6株与该罕见进化枝2.3.2.1 H5 N6株的产生密切相关。与其他三种HPAI H5病毒在小鼠中显示中等毒力不同，针对进化枝2.3.2.1 H5 N6的同源内部基因星座的H5 N1株具有高致病性，这可能归因于H3亚型衍生的PB 1基因。然而，与进化枝2.3.4.4 H5 N6祖先相比，进化枝2.3.2.1 H5 N6抗性株在小鼠中显示更广泛的组织分布和更高的病毒滴度，这可能有助于病毒在自然界中的维持和传播。因此，我们的研究结果强调，需要加强对LPMs中H5亚型HPAI病毒的持续流行病学调查，以防止地方性病毒对新型疫苗的潜在家禽甚至公共卫生威胁。
In recent years in China, clade 2.3.4.4 H5N6 plus clade 2.3.2.1 H5N1 subtype highly pathogenic avian influenza (HPAI) viruses have gradually become endemic in poultry, and their co-circulation could inevitably facilitate the gene reassortment between each other. During our routine surveillance in live poultry markets (LPMs) in eastern China in 2017-2018, a novel reassortant H5N6 strain with the HA gene derived from clade 2.3.2.1 was isolated from the cloacal swabs of apparently healthy ducks. Phylogenetic tracing analysis indicated that another two clade 2.3.2.1 H5N1 strains with divergent lineages of PB1 gene and one clade 2.3.4.4 H5N6 isolate of the dominant genotype sharing spatio-temporal proximity were intimately involved in the generation of this rarely reported clade 2.3.2.1 H5N6 reassortant. Distinct with the other three HPAI H5 viruses showing moderate virulence in mice, the H5N1 strain of the homologous internal gene constellation against the clade 2.3.2.1 H5N6 reassortant was highly pathogenic, which might probably attribute to the H3 subtype-derived PB1 gene. However, as compared to the clade 2.3.4.4 H5N6 ancestor, the clade 2.3.2.1 H5N6 reassortant displayed a broader tissue distribution and higher viral titres in mice, which could likely facilitate the viral maintenance and spread in nature. Therefore, our results highlight that continuous epidemiological survey of H5 subtype HPAI viruses in LPMs needs to be strengthened to prevent the potential poultry or even public health threat of the novel reassortants from endemic viruses.