College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China.
Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai, People's Republic of China.
Sci Rep. 2020 Nov 25;10(1):20583. doi: 10.1038/s41598-020-76541-0.
H6 subtype avian influenza viruses spread widely in birds and pose potential threats to poultry and mammals, even to human beings. In this study, the evolution and pathogenicity of H6 AIVs isolated in live poultry markets from 2011 to 2017 were investigated. These H6 isolates were reassortant with other subtypes of influenza virus with increasing genomic diversity. However, no predominant genotype was found during this period. All of the H6N2 and most of the H6N6 isolates replicated efficiently in lungs of inoculated mice without prior adaptation. All of the H6N2 and two H6N6 isolates replicated efficiently in nasal turbinates of inoculated mice, which suggested the H6N2 viruses were more adaptive to the upper respiratory tract of mice than the H6N6 viruses. One of H6N2 virus caused systemic infection in one out of three inoculated mice, which indicated that H6 avian influenza virus, especially the H6N2 viruses posed a potential threat to mammals. Five H6 strains selected from different genotypes caused no clinical signs to inoculated chickens, and their replication were limited in chickens since the viruses have been detected only from a few tissues or swabs at low titers. Our study strongly suggests that the H6 avian influenza virus isolated from live poultry markets pose potential threat to mammals.
H6 亚型禽流感病毒广泛存在于鸟类中，对家禽和哺乳动物，甚至人类构成潜在威胁。本研究调查了 2011 年至 2017 年活禽市场分离的 H6 AIV 的进化和致病性。这些 H6 分离株与其他亚型的流感病毒重配，基因组多样性增加。然而，在此期间并未发现主要基因型。所有 H6N2 和大多数 H6N6 分离株在未适应的情况下在接种小鼠的肺部有效复制。所有 H6N2 和两种 H6N6 分离株均在接种小鼠的鼻甲骨中有效复制，这表明 H6N2 病毒比 H6N6 病毒更适应小鼠的上呼吸道。其中一种 H6N2 病毒在接种的三只小鼠中有一只引起全身感染，这表明 H6 禽流感病毒，尤其是 H6N2 病毒对哺乳动物构成潜在威胁。从不同基因型中选择的 5 株 H6 株未引起接种鸡出现临床症状，其在鸡中的复制受到限制，因为这些病毒仅在少数组织或拭子中以低滴度检测到。我们的研究强烈表明，从活禽市场分离的 H6 禽流感病毒对哺乳动物构成潜在威胁。
