4株H5N6亚型禽流感病毒毒株的分离鉴定与致病性研究

摘要

The purpose of this study was to investigate the biological characteristics of 4 H5N6 subtype avian influenza virus isolates,and their pathogenicity to chickens.In this study,the clinical samples between 2015-2016 year in Guangdong were used to isolate virus,and the isolates were identified,the genes of isolates were cloned,sequenced and analyzed,then 4 weeks old SPF chickens were infected by the way of intranasal and eyedrop inoculation.Our results showed that 4 strains of H5N6 avian influenza virus were isolated,their HA gene belonged to Clade 2.3.4.4,and the isolates contained multiple basic amino acids at the cleavage site,which were characteristic of highly pathogcnic AIV.The inoculation results showed that all chickens of the attack group died in 5 d,and the chickens of cohabitation group died in 9 d;the infected chickens could shed virus continuously.And the avian influenza virus could be detected in the heart,liver,spleen,lung,kidney,brain in high titer and caused extensive pathological damage.The 4 strains of H5N6 subtype avian influenza virus isolates showed high pathogenicity and horizontal transmission ability to chickens,suggesting the need to strengthen the prevention and control of H5N6 subtype avian influenza.%本研究旨在研究4株H5N6亚型禽流感病毒分离株的生物学特性与对鸡的致病性.对201 5 2016年广东地区的临床送检样品进行病毒分离鉴定,对分离株进行基因克隆、测序和序列分析,并对4周龄SPF鸡点眼、滴鼻攻毒.结果分离得到4株H5N6亚型禽流感病毒,其HA基因属于Clade2.3.4.4,HA蛋白的裂解位点处具有多个连续碱性氨基酸,具备高致病性禽流感病毒的分子特征.攻毒组鸡5d内全部死亡,同居组9d内全部死亡;攻毒后鸡持续排毒,在心、肝、脾、肺、肾、脑等组织脏器中病毒滴度高,且对组织造成广泛性损伤.4株所测试的H5N6亚型禽流感病毒分离株对鸡具有高致病性和水平传播能力,提示需加强H5N6亚型禽流感的防控.