两株H3N1亚型禽流感病毒(AIV)的生物学特性

摘要

H3N1 subtype Avian influenza virus (AIV) can infect wild birds,poultry,pigs (Sus scrofa) and dogs (Canis lupus familiaris).In order to understand the biological property of H3N1 subtype AIV,phylogenetic analysis and specific pathogen free (SPF) animal infection experiments were conducted for two H3N1 strains,A/environment/Anhui/S4108/2011 (EN/AH/S4108/2011) and A/duck/Fujian/S2196/2012 (DK/FJ/S2196/ 2012) which were isolated from Anhui and Fujian province in 2011 and 2012,respectively.The phylogenetic analysis showed that the genetic origin of the two stains were obviously diversified.The neuraminidase (NA) and matrix protein (M) genes of DK/FJ/S2196/2012 and the polymerase basic protein 1 (PB1),NA,and nonstructural protein (NS) genes of EN/AH/S4108/2011 were most closely related to those of H5N1 AIVs.Besides,these two viruses shed only through oropharyngeal route of infected chickens (Gallus gallus) and didn't have the ability to horizontal transmission.The two viruses could efficiently replicate in the nasal turbinates and lungs of infected mice (Mus musculus) without prior adaptation.In addition,these two viruses did not cause any obvious clinical symptoms of infected mice,and thereby they were low pathogenic to mice.In conclusion,two H3N1 viruses showed genetic diversity and complexity in their origin and had a low potential risk to infect mammals.This study indicated that HSN1 AIVs in eastern China were involved in reassortment with H3N 1 subtype AIVs genome,which provides scientific basis for prevention and control of H3N1 subtype AIVs.%H3N1亚型流感病毒(Avian influenza virus,AIV)除了可以感染野鸟和家禽外,还可以感染猪(Susscrofa)和犬(Canis lupus familiaris).为了解H3N1亚型AIV的生物学特性,本研究对2011年安徽省和2012年福建省分离到的两株H3N1亚型AIVs A/environment/Anhui/S4108/2011(简称EN/AH/S4108/2011)和A/duck/Fuj ian/S2196/2012(简称DK/FJ/S2196/2012)进行遗传演化分析及无特定病原(specific pathogenfree,SPF)动物感染实验.结果表明,这2株病毒的基因来源具有明显的遗传多样性,DK/FJ/S2196/2012的神经氨酸酶(neuraminidase,NA)基因和基质蛋白(matrix protein,M)基因,EN/AH/S4108/2011的碱性聚合酶蛋白l(polymerase basic protein 1,PBl)基因、NA和非结构蛋白(non-structural protein,As)基因与H5N1亚型AIV的亲缘关系最近.这两株病毒仅能通过鸡(Gallus gallus)的上呼吸道向外排毒,不具有水平传播的能力.SPF BALB/c小鼠(Mus musculus)感染性实验结果显示,这两株病毒均能在小鼠的鼻甲骨和肺脏进行有效复制,但小鼠感染后并不表现出任何明显的临床症状,病毒对小鼠均呈现低致病性.研究结果显示,两株H3N1亚型AIV的基因来源复杂,感染哺乳动物的潜在风险较小.本研究发现我国华东地区H5N1亚型AIV参与了H3N1亚型AIV的基因重排,研究结果为H3N1亚型AIV的综合防控提供了科学依据.