4株鸽新城疫病毒的基因组序列与致病性分析  

Genome Sequencing and Pathogenicity Analyses of Four Isolates of the Newcastle Disease Virus in Pigeons

作　　者：裴育 孙雅丽 赵烨[1] 张国中[1,2] 薛佳[1] PEI Yu;SUN Yali;ZHAO Ye;ZHANG Guozhong;XUE Jia(College of Veterinary Medicine,Chma Agricultural University,Beijing 100193,China;Diagnosis and Research Center of Livestock and Poultry Diseases,China Agricultural University,Beijing 100193,China)

机构地区：[1]中国农业大学动物医学院,北京100193 [2]中国农业大学畜禽疫病诊断研究中心,北京100193

出　　处：《病毒学报》2022年第2期402-414,共13页Chinese Journal of Virology

基　　金：现代农业产业技术体系北京市家禽创新团队(项目号:BAIC04-2020)。

摘　　要：本研究对从北京、天津以及山东地区发病鸽群中分离到的4株鸽新城疫病毒(Newcastle disease virus,NDV)进行基因组测序和遗传进化分析,并进一步比较这些毒株对鸽子的致病性。研究通过特异性引物扩增4株鸽NDV的全长基因组序列后与GenBank上已登陆的所有鸽NDV毒株的序列进行遗传进化分析;通过病毒生物学特性的测定比较分离株的毒力;通过病毒感染1月龄肉鸽,检测分离株对鸽子的致病性。结果显示4株鸽NDV毒株均属于ClassⅡ类基因Ⅵb亚型病毒,其中Pigeon/China/BJ2018株、Pigeon/China/TJ2017株和Pigeon/China/BJ2013株属于VIb/4bii f亚型,Pigeon/China/SD2012株属于VIb/4bii d亚型。4株病毒与目前国内鸽NDV流行株属于同一进化分支,与鸡源经典疫苗株La Sota属于不同进化分支。对这四个毒株进行生物学特性测定,均为中等毒力毒株。4株病毒中,Pigeon/China/BJ2018株对1月龄肉鸽的致病性最强,通过肌肉注射途径攻毒后3d肉鸽开始表现临床症状,攻毒后第5d开始出现死亡,累计死亡率高达70%;剖检可见感染肉鸽气管有出血点、脾脏出血、肾脏苍白、十二指肠出血;病理组织学观察显示,感染鸽脑组织损伤明显;组织病毒载量检测显示,病毒在脑和脾脏中大量存在,在脑组织中的病毒载量最高。本研究系统分析了4株鸽NDV国内分离株的遗传进化特点和对鸽子的致病性,从中筛选出一株致病性较强的毒株作为疫苗检验强毒,对提高鸽新城疫的防控有积极意义。Genome sequencing and analyses of genetic evolution were undertaken on four strains of the Newcastle Disease Virus(NDV)isolated from infected pigeons in Beijing,Tianjin and Shandong in China.Furthermore,the pathogenicity of these strains in pigeons was compared. After amplification of the full-length genomic sequences of these four NDV strains with specific primers,genetic evolution was analyzed with all the NDV strains in pigeons on GenBank. The virulence of the isolates was compared by determining the biological characteristics of the NDV. The pathogenicity of the isolated strains to pigeons was detected by viral infection of1-month-old pigeons. Results showed that all the NDV strains in our study belonged to class Ⅱ,subtype Ⅵb.Pigeon/China/BJ2018,Pigeon/China/TJ2017 and Pigeon/China/BJ2013 belonged to the VIb/bii4 f subtype.Pigeon/China/SD2012 belonged to the VIb/bii 4 d subtype. The four isolates belonged to the same evolutionary branch as the NDV epidemic strain in pigeons in China,and belonged to different evolutionary branches from the classic chicken vaccine strain La Sota. The biological characteristics of these four strains were determined:they were all mesogenic virulent strains. Among the four strains,Pigeon/China/BJ2018 had the highest pathogenicity to 1-month-old pigeons. The pigeons began to show clinical symptoms 3 days post-challenge(dpc),and began to die on 5 dpc,with cumulative mortality reaching 70%. Necropsy showed that the trachea,spleen and duodenum of infected pigeons had bleeding,along with kidney pallor. Histopathology showed damage to the brain tissue of infected pigeons. Viral-load tests of tissues demonstrated that the virus was abundant in the brain and spleen,with the highest viral load in brain tissue. In conclusion,the genetic-evolution characteristics and pathogenicity of four isolates of the NDV from pigeons in China were analyzed. One strain with strong pathogenicity could be a candidate for vaccine development against the NDV in pigeons.

关 键 词：鸽新城疫 遗传进化分析 致病性 

分 类 号：S855.3[农业科学—临床兽医学]