H9亚型禽流感病毒HF株的分离鉴定和免疫原性评价  

Isolation,Identification and Immunogenicity Evaluation of H9N2 Subtype Avian Influenza Virus HF Strain

作　　者：程艺 田辉 张亚 薛景景 盛东北 刘武杰 王婉冰 张盼涛 田克恭 CHENG Yi;TIAN Hui;ZHANG Ya;XUE Jingjing;SHENG Dongbei;LIU Wujie;WANG Wanbing;ZHANG Pantao;TIAN Kegong(National Research Center for Veterinary Medicine,Luoyang 471000,China)

机构地区：[1]国家兽用药品工程技术研究中心,洛阳471000

出　　处：《中国畜牧兽医》2020年第9期2945-2952,共8页China Animal Husbandry & Veterinary Medicine

基　　金：郑洛新国家自主创新示范区创新引领型产业集群项目(181200211700)。

摘　　要：2015年,从安徽合肥某养鸡场分离出一株H9N2亚型禽流感病毒(AIV),命名为HF株。该毒株鸡胚半数感染量(EID50)为10^9.17/0.1 mL,最小致死量的平均死亡时间(MDT)为87 h。对其HA基因分析发现,其氨基酸裂解位点为RSSR↓GLF,符合低致病性AIV特征;HA基因的遗传进化分析结果表明,该分离株属于h9.4.2.5谱系,符合当前毒株流行趋势。将HF株与2006-2018年分离自全国各地的10株H9N2亚型AIV分离株同时制备灭活疫苗,免疫SPF鸡,制备阳性血清,通过交叉血凝抑制试验分析病毒抗原性,结果显示HF株与2014年之前毒株抗原相关性介于0.50~0.56之间,与2014年及之后毒株抗原相关性介于0.89~1.00之间,表明该分离株与2014年之后的流行毒株具有良好的抗原相关性。用0.2%甲醛灭活HF株病毒液,其HA效价在灭活前后未发生变化;用灭活抗原制备油乳剂灭活疫苗免疫SPF鸡,免疫后21 d HI抗体效价几何平均值达到9.0log2以上,可使免疫鸡完全抵抗H9亚型AIV的感染,提供100%的攻毒保护。研究结果表明,HF株具有良好的免疫原性,可作为疫苗候选株用于H9N2亚型禽流感疫苗的研制。In 2015,an H9N2 subtype avian influenza virus(AIV)strain was isolated from a chicken farm in Hefei,Anhui,and named HF strain.The results of the chicken embryo proliferation characteristics study showed that the half infection rate of chicken embryo(EID50)was 10^9.17/0.1 mL,and the mean time to death for minimum lethal dose(MDT)was 87 h.The analysis result of HA gene showed that its amino acid cleavage site was located in RSSR↓GLF,which accorded with the characteristics of low pathogenic avian influenza.The genetic evolution analysis of HA gene revealed that the isolate belonged to the h9.4.2.5 lineage,which accorded with the current virus strain epidemic characteristics.The HF strain was prepared with 10 H9N2 subtype AIV isolates which isolated from all over the country from 2006 to 2018 to prepare inactivated vaccines,immunize SPF chickens,prepare positive sera,and analyze the virus antigenicity by cross hemagglutination inhibition test.The results showed that the correlation between the HF strain and the virus antigens before 2014 and was between 0.50-0.56,and the virus antigen correlation after 2014 was 0.89-1.00.This showed that the isolate had good antigenic correlation with epidemic strains in recent years.Inactivate HF strain virus solution with 0.2%formaldehydel,and its HA titer did not change before and after inactivation.After the inactivated virus solution was prepared into an oil emulsion inactivated vaccine to immunize SPF chickens,21 days after immunization,the average value of the HI antibody titer reached 9.0log2.It could make immune chicken completely resistant to H9 subtype AIV infection and provide 100%protection from challenge.The above research results showed that the HF strain had good immunogenicity and could be used as a vaccine candidate strain for the prevention of H9N2 subtype AIV.

关 键 词：H9N2亚型禽流感病毒 分离鉴定 遗传进化 免疫原性 

分 类 号：S852.65[农业科学—基础兽医学]