一株鸽源H10N8亚型禽流感病毒的遗传进化分析及小鼠感染特性的研究

Genetic analysis of an H10N8 subtype avian influenza virus from pigeon and its viral infectivity to mice

为了解从江苏某活禽市场分离鉴定出的一株鸽源H10N8亚型禽流感病毒(AIV)A/pigeon/Jiangsu/JYP090602/2019株的生物学特性,本研究对该分离株进行空斑纯化和全基因组测序,并以10^(6) EID_(50)病毒感染BALB/c小鼠进行致病性研究。序列分析结果显示,该病毒HA基因的裂解位点为334PEIMQGR↓GLF^(343),只含有一个碱性氨基酸,为低致病性AIV的分子特征。其HA基因与A/chicken/Zhejiang/102622/2016(H10N8)株HA基因的同源性达98.7%,NA基因与A/pigeon/Longquan/LQ67/2016(H2N8)株NA基因的同源性达96.5%,内部基因PB2、PB1、PA、M、NP和NS分别与H7N3、H1N9、H10N7、H1N2、H7N3和H11N3亚型AIV相应基因的同源性最高,具有遗传多样性。小鼠感染试验结果显示,该病毒仅引起小鼠体质量轻微变化,但能够在小鼠的肺脏和心脏中复制,肺脏病毒滴度为4.74 lg EID_(50)/mL,且可引起肺部组织病变。上述结果表明该病毒株为新型重组病毒,对小鼠具有一定致病性,本研究为H10亚型禽流感的预警和防控提供一定的参考依据。

To investigate the biological characteristics of a pigeon-derived H10N8 subtype avian influenza virus(AIV),A/pigeon/Jiangsu/JYP090602/2019,isolated and identified from a live poultry market in Jiangsu.In this study,the virus was subjected to plaque purification and its complete genome was sequenced.BALB/c mice were infected with 10^(6)EID_(50) of virus to study its pathogenicity.Sequence analysis showed that the cleavage site of the HA gene of the virus was 334PEIMQGR↓GLF^(343),which contained only one basic amino acid,implying a characteristic of the low pathogenic AIV.The homology of HA gene reached 98.7%compared with that of A/chicken/Zhejiang/102622/2016(H10N8),and the homology of NA gene reached 96.5%compared with that of A/pigeon/Longquan/LQ67/2016(H2N8).The internal genes,PB2,PB1,PA,M,NP,and NS,had the highest homo-logies with each corresponding gene from H7N3,H1N9,H10N7,H1N2,H7N3,and H11N3 subtype AIVs,suggesting that the strain has genetic diversity.The mice infection assay showed that the virus caused only slight changes in body weight but was able to replicate in the lungs and hearts with the average viral titer in lungs of 4.74 lgEID_(50)/mL,resulting in lung tissue lesions.These results indicated that the isolate is a new reassortant and is low pathogenic to mice.This study provided a certain reference basis for the early warning,prevention and control of H10 subtype avian influenza.