摘要
为了解鸡马立克氏病毒(MDV)在我国鸡群中的流行情况,本研究于2021年从福建省已免疫鸡马立克氏病(MD)疫苗鸡群且发生疑似MD病例的鸡场采集21份疑似发病蛋鸡外周血,分离其淋巴细胞接种鸡胚成纤维细胞(CEF),5 d后收集病毒,盲传1~2代后获得21株能够形成典型MDV蚀斑的分离株,依次命名SW1~SW21,采用PCR分别扩增MDV血清Ⅰ型(MDV-1) Meq基因、Ⅱ型(MDV-2) ORF873基因、Ⅲ型(MDV-3) US3基因进行MDV分型鉴定,扩增鸡传染性贫血病毒(CAV) VP3基因、禽网状内皮组织增殖病病毒(REV) LTR基因、禽白血病病毒A亚群(ALV-A)、B亚群(ALV-B)、J亚群(ALV-J)的env基因进行外源病毒检测,结果显示MDV-1均为阴性,MDV-2均为阳性,MDV-3阳性率为38.1%(8/21),未检测到外源病毒基因。在MDV-2分离株中选择SW14株进行pp24基因的PCR扩增,测序后与MDV-2参考株SB-1、301B/1、HPRS24的pp24基因进行基因序列比对分析,结果显示,SW14和SB-1株同源性(96.3%)最高。通过透射电镜观察SW14,可见分离株呈双环型,直径约110 nm,符合MDV病毒粒子形态特征。本研究证实该鸡场中存在MDV-2流行,可能会影响疫苗的免疫效果,但其致病性有待进一步研究。本研究从疑似发病蛋鸡中分离到新的MDV-2株,为我国MDV-2的研究提供重要参考依据,同时为我国MD疫情防控提供有价值的研究材料。
To investigate the prevalence of Marek's disease virus(MDV)in chickens,we collected 21 peripheral blood samples of suspected MDV-infected layers from immunized chicken farms in Fujian Province in 2021.Lymphocytes were isolated and inoculated into chicken embryo fibroblasts(CEF),resulting in the isolation of 21 strains capable of forming typical MDV plaques,which were named SW1 to SW21.MDV typing was performed by PCR to qualify the Meq gene of MDV serum type I(MDV-1),the ORF873 gene of type II(MDV-2),and the US3 gene of type III(MDV-3).Amplification of chicken anemia virus(CAV)VP3 gene,the LTR gene of reticuloendotheliosis virus(REV),the env gene of subgroup A,B,J avian leucosis virus(ALV)was performed to test for foreign viruses.The results showed that all MDV-1 types were negative,while MDV-2 types were positive,with MDV-3 types accounting for 38.1%(8/21),and no foreign virus genes were detected.SW14 was selected from MDV-2 isolates for pp24 gene amplification and nucleotide sequence alignment analysis with MDV-2 reference strains SB-1,301B/1 and HPRS24.The results revealed the highest homology(96.3%)between SW14 and SB-1.The SW14 was observed by transmission electron microscopy,and the findings were consistent with the morphological characteristics of MDV particles.This study indicates the prevalence of MDV-2 in the studied flock,which could potentially affect the vaccine's immune response,though further research is required to assess its pathogenicity.In this study,the isolation of a new MDV-2 strain from suspected disease-onset layer chickens provided a crucial theoretical foundation for the investigation of MDV-2 and valuable research materials for the prevention and control of local MD epidemics in China.
作者
林雨萌
胡明雪
刘长军
葛成菲
郭榕容
李凯
崔红玉
高立
祁小乐
王素艳
王笑梅
高玉龙
张艳萍
LIN Yu-meng;HU Ming-xue;LIU Chang-jun;GE Cheng-fei;GUO Rong-rong;LI Kai;CUI Hong-yu;GAO Li;QI Xiao-le;WANG Su-yan;WANG Xiao-mei;GAO Yu-long;ZHANG Yan-ping(State Key Laboratory for Animal Disease Control and Prevention,Harbin Veterinary Research Institute,Chinese Academy of Agriculture Sciences,Harbin 150069,China)
出处
《中国预防兽医学报》
CAS
CSCD
北大核心
2023年第8期864-868,共5页
Chinese Journal of Preventive Veterinary Medicine
基金
国家自然科学基金(U21A20260、32170170)
现代农业产业体系肉鸡体系(CARS-41)。
