一株具有插入和缺失突变特征鸭腺病毒B2毒株的分离鉴定  

Isolation and Identification of a New Duck Adenovirus B2 with Insertion and Deletion Mutations

作　　者：郭博伦 李雅汝 郑欣 江丹丹 曾丽 陈少莺[2,3] 马燕梅 陈仕龙[2,3] GUO Bolun;LI Yaru;ZHENG Xin;JIANG Dandan;ZENG Li;CHEN Shaoying;MA Yanmei;CHEN Shilong(College of Animal Sciences,Fujian Agricultural and Forestry University/Joint Laboratory of Animal Pathogen Prevention and Control of Fujian-Nepal,Fuzhou,Fujian 350002,China;Institute of Animal Husbandry and Veterinary Medicine,Fujian Academy of Agriculture Sciences,Fuzhou,Fujian 350013,China;Fujian Animal Diseases Control Technology Development Center,Fuzhou,Fujian 350003,China)

机构地区：[1]福建农林大学动物科学学院/福建省-尼泊尔畜禽重大疫病防控联合实验室,福建福州350002 [2]福建省农业科学院畜牧兽医研究所,福建福州350013 [3]福建省畜禽疫病防治工程技术研究中心,福建福州350013

出　　处：《福建农业学报》2024年第2期125-130,共6页Fujian Journal of Agricultural Sciences

基　　金：福建省科技计划公益类专项(2019R1026-11);福建省农业科学院科技创新团队建设项目(CXTD2021034);福建省农业高质量发展超越“5511”协同创新工程项目(XTCXGC2021018、XTCXGC2021012);福建农林大学科技创新专项基金(KFB23098A)。

摘　　要：【目的】对一份疑似鸭腺病毒B2(Duck adenovirus B2,DAdV B2)感染的番鸭白肝病的病例进行确诊,并对分离株进行测序,为福建省DAdV B2流行病学研究提供参考。【方法】开展病料PCR检测,并进行病毒的分离鉴定、全基因二代测序,利用MegAlign和SnapGene软件对测序结果进行同源性及遗传进化分析,再进行动物回归试验,确定对雏番鸭的致病性。【结果】病料样本检测为DAdV B2阳性,并成功分离到一株DAdV B2毒株,命名为DAdV B2/BG48。该分离株感染鸡肝癌细胞(LMH)后细胞变大变圆、最后死亡崩解,形成特征性细胞病变;感染MDEF后细胞由长梭形变为圆形并聚集,细胞间出现空隙。测序结果表明,BG48基因组在pX基因区域中有3 bp的插入,在ORF19B基因区域有33 bp的插入,在ORF64和ORF67基因区域的交界处有42 bp的缺失,ORF67基因起始密码子往后第133位碱基为G,没有突变为终止密码子,其他编码基因与CH-GD-12-2014、实验室之前鉴定的BG27和BG18无特征性差异。动物回归试验显示,2日龄的番鸭对DAdV B2分离株BG48易感,致病率为50%,死亡率为0,发病鸭可见与自然感染病鸭相似的临床症状和病理变化。【结论】成功从番鸭白肝病病例中分离鉴定1株DAdV B2突变株BG48,BG48具有多位点插入和缺失特征,提示DAdV B2毒株容易突变,临床流行毒株复杂。本结果为DAdV B2的分子流行病学调查和遗传进化研究提供了参考。【Objective】A previously unknown strain of duck adenovirus B2(DAdV B2)was isolated from a ducking of pale liver disease in Fujian and identified for epidemiological reference.【Methods】The virus associated with the disease was detected by PCR and isolated for identification by genome sequencing and a challenge test.【Result】The DAdV B2/BG48 virus infected LMH cells in the duck became swollen like a ballon,and eventually,died and disintegrated.The MDEF cells inoculated with the isolate changed from a spindle-shape to ball-like and clustered together with intercellular spaces in between.Distinctively,BG48 genome had a 3 bp insertion in the pX region,a 33 bp insertion in the ORF19B domain,and 42 bp deletion at the junction between ORF64 and ORF67.A G-base was found on the 133rd spot after the starting code of ORF67 and no truncated mutation in the terminal nor other codes compared with CH-GD-12-2014,or BG27 and BG18 previously identified.In a challenge test,BG48 induced a 50%morbidity and 0 mortality on 2-day-old Muscovy ducks with similar clinical symptoms and pathological changes between the artificially infected and the naturally diseased birds.【Conclusion】A novel DAdV B2 strain,BG48,from a Muscovy duck of pale liver disease was isolated and identified.The virus was uniquely characterized by multiple insertions and deletion mutations in the gene suggesting a potential of causing complex epidemic.

关 键 词：番鸭白肝病 鸭腺病毒B2 分离鉴定 插入和缺失 ORF67 

分 类 号：S858.32[农业科学—临床兽医学]