一株鸭源H6N6亚型禽流感病毒的全基因组序列分析及对小鼠的感染性研究

为了解H6N6亚型禽流感病毒(AIV)的生物学特性,本研究对2015年在广东活禽交易市场分离的一株鸭源AIV DK/GD/S1182/2015(H6N6)进行了全基因组测序、遗传演化分析和对BALB/c小鼠的感染性试验。序列分析显示,该病毒的HA蛋白裂解位点处仅有一个碱性氨基酸,符合低致病性AIV的分子特征;HA蛋白的222V和228S,可以增强病毒对α-2,6唾液酸受体的结合能力。NA蛋白颈部有11个氨基酸的缺失,这将会影响NA的神经氨酸酶活性;该病毒可能是2010年广东H6N6猪流感病毒与2014年广西AIV重组产生。小鼠感染性试验表明,该分离株不需要预先适应就能够在小鼠的肺脏内高效复制,提示该分离株具有感染哺乳动物的潜在风险。本研究对H6亚型AIV监测和相关生物学特性研究具有一定的指导作用。

Sequence analysis and pathogenicity analysis of an avian H6N6influenza virus isolated from a duck

An H6N6 subtype avian influenza virus DK/GD/S1182/2015(H6N6)was isolated from a live poultry market in Guangdong in 2015.The complete genome was sequenced for genetic and phylogenetic analysis.The potential risk of the virus to mammals was evaluated in BALB/c mice.The results showed that the amino acid residues in HA cleavage site is 339 PQIETR↓GL346,which is consistent with the low pathogenic molecular characteristics.Compared with the amino acid residues in consensus sequence of avian influenza viruses,two mutations were found at positions 222(alanine to valine)and 228(glycine to serine)of hemagglutinin(HA)protein,which may affect the receptor-binding properties of the virus.The neuraminidase(NA)protein possess an 11-amino acid deletion in the neck that may affect neuraminidase activity.This virus may be a recombinant of the swine-and avian-origin influenza viruses.The experimental infection in mice showed that the virus could replicate efficiently in the lung without prior adaptation,suggesting that the virus has a potential risk to mammals.This study will contribute to understand the biological characteristic of H6N6 subtype avian influenza virus.