新型H3N8亚型禽流感病毒SQ03株的分离鉴定与免疫原性评价  

Isolation,Identification and Immunogenicity Evaluation of Novel H3N8 Subtype Avian Influenza Virus SQ03 Strain

作　　者：张盼涛 朱巧艳 王勋 王莹 高艳艳 高彬文 张贺伟 ZHANG Pantao;ZHU Qiaoyan;WANG Xun;WANG Ying;GAO Yanyan;GAO Binwen;ZHANG Hewei(Luoyang Polytechnic,Luoyang,Henan 471000;Animal Diseases and Public Health Engineering Research Center of Henan Province,Luoyang,Henan 471000;Luoyang Key Laboratory of Diagnosis and Immunoprophylaxis of Animal Viral Diseases,Luoyang,Henan 471000;Luoyang Zhongke Gene Testing and Diagnosis Center Co.,Ltd.,Luoyang,Henan 471000)

机构地区：[1]洛阳职业技术学院,河南洛阳471000 [2]河南省动物疫病与公共卫生工程研究中心,河南洛阳471000 [3]洛阳市动物病毒病诊断与免疫预防重点实验室,河南洛阳471000 [4]洛阳中科基因检测诊断中心有限公司,河南洛阳471000

出　　处：《中国家禽》2024年第11期78-86,共9页China Poultry

基　　金：中原英才计划“育才系列”中原科技创新青年拔尖人才项目(2023年)。

摘　　要：为研究我国H3N8亚型禽流感病毒(AIV)遗传变异情况,研究从江苏某商品蛋鸡群采集病料进行病原分离鉴定、血凝素(HA)基因遗传进化分析、SPF鸡回归试验,并采用分离病毒制备油乳剂灭活疫苗免疫SPF鸡,评价其免疫原性。结果显示:分离病毒为新型H3N8亚型(AIV),命名为A/chicken/Suqian/SQ03/2022(H3N8),以下简称SQ03株;该分离株HA基因属于欧亚禽分支,HA蛋白的裂解位点为PEKQTR↓GLF,为低致病性AIV,与我国2021—2022年分离的鸡源H3N8亚型AIV同源性最高,核苷酸相似性为98.6%~99.5%,而与我国2005年分离的鸭源毒株核苷酸相似性仅为87.8%,并且HA基因发生了较大的遗传变异;SQ03株按照106.0 EID50/只滴鼻途径感染SPF鸡后第3天出现甩鼻、张口呼吸等临床症状,感染后第5天排毒率达到100%,剖检可观察到鼻甲和气管内有黏液渗出物、肾脏肿大等病变;SPF鸡免疫油乳剂灭活疫苗后14 d HI抗体效价几何平均值达到8.2 log2,免疫后21 d达到10.3 log2,可为免疫鸡提供针对H3N8亚型AIV的完全攻毒保护。研究表明,SQ03株为我国当前流行的新型H3N8亚型AIV,具有较强致病性和良好的免疫原性,可作为新型H3N8亚型禽流感灭活疫苗的效力检验用毒和疫苗候选株。In order to study the genetic variation of H3N8 subtype avian influenza virus(AIV)in China,suspected samples were collected from a commercial laying hens flock in Jiangsu province,and virus isolation and identification,hemagglutinin(HA)gene phylogenetic analysis and SPF chicken infection experiment were carried out,the oil emulsion inactivated vaccine prepared by the isolated virus was immunizated SPF chickens to evaluate the immunogenicity.The results showed that the isolated virus was identified as a novel H3N8 subtype AIV,named A/chicken/Suqian/SQ03/2022(H3N8),hereinafter referred to as SQ03 strain.The HA gene of SQ03 strain was part of the Eurasian avian H3 gene,belonged to the low pathogenic AIV based on the proteolytic cleavage sites of HA protein,which was PEKQTR↓GLF.The nucleotide homology of HA gene of SQ03 strain was 98.6%-99.5%with chicken isolates from 2021-2022,while the homology with duck isolates from 2005 was only 87.8%,and there was a large genetic variation in HA gene.SPF chickens were infected by SQ03 strain with 106.0 EID50/bird via nasal route,clinical symptoms such as sneezing and open-mouth breathing were observed on day 3 post-infection.The shedding rate of the virus reached 100%on day 5 post-infection,and pathological changes such as mucus exudate in the nasal turbinates and trachea,and enlarged kidneys were observed at necropsy.The geometric mean value of HI antibody titer of SPF chickens immunizated with oil emulsion inactivated vaccine prepared by this strain reached 8.2 log2 at 14 days after immunization and 10.3 log2 at 21 days after immunization,which could provide complete protection against H3N8 subtype AIV infection for immunized chikens.The results indicated that SQ03 strain was a new H3N8 subtype AIV currently circulating in China,with high pathogenicity and good immunogenicity,could be used to evaluate the protection of vaccine and as a candidate strain for novel H3N8 subtype avian influenza inactivated vaccine.

关 键 词：H3N8亚型禽流感病毒 蛋鸡 HA基因 灭活疫苗 免疫原性 

分 类 号：S852.65[农业科学—基础兽医学]