对一株超强马立克氏病毒株的检测和研究  

Detection and Analysis of a Very Virulent Marek's Disease Virus Strain

作　　者：张康[1,2] 龚振华[1] 林祥超 郭光礼[3] 杜翔[1] 王丽萍 于建敏[1] 李金平[1] 侯广宇[1] 单虎[2] 

机构地区：[1]中国动物卫生与流行病学中心,山东青岛266032 [2]青岛农业大学,山东青岛266109 [3]临朐县畜牧局,山东临朐262600 [4]青岛易邦生物工程有限公司,山东青岛266032

出　　处：《中国动物检疫》2015年第4期14-17,31,共5页China Animal Health Inspection

基　　金：农业部科技计划项目;青岛市科技计划项目支持

摘　　要：对从发病鸡场分离到的一株超强马立克氏病毒株,用PCR扩增该分离毒株的meq致瘤基因并测定了其序列,发现其与超强病毒株SD2012-1的核苷酸同源性为99%。该分离毒株的meq基因序列在第575-577位比疫苗株CVI988/Rispens的meq基因序列多插入3个碱基（CAC）,与SD2012-1相同。使用该分离毒株进行疫苗免疫攻毒实验,未免组的发病率为80.0%,常规剂量HVT组和10×常规剂量HVT组的发病率分别为73.0%和76.6%,HVT不能提供有效免疫保护。常规剂量CVI988组和10×常规剂量CVI988组的发病率分别为30.0%和30.0%,常规剂量HVT＋CVI988组和10×常规剂量HVT＋CVI988组的发病率分别为26.6%和26.7%,免疫CVI988疫苗组鸡和HVT＋CVI988联苗组鸡的发病率比免疫HVT疫苗组鸡低。说明,野外毒株的不断变异已经突破现有疫苗的免疫保护,会给养鸡业带来严重的损失。In this study,a very virulent Marek＇s disease virus（vv MDV） strain was isolated from the infected chicken farm. The meq gene of the isolated strain was amplified by PCR and sequenced. It was found that nucleotide homology of the isolated strain with the very virulent virus strain SD2012-1 was as high as 99%. Compared with the vaccine strain CVI988/Rispens,3 bases（CAC） were inserted at site 575-577 of meq gene of the isolate and SD2012-1. Virus challenge and vaccination showed that the incidence in the unimmunized group was 80.0%;the incidence in conventional-dose HVT group and 10×conventional-dose HVT group were 73.0% and 76.6% respectively. HVT couldn＇t provide effective protection. The incidence of conventional-dose CVI988 group and the 10×conventional-dose group CVI988 was both 30.0%. The incidence of conventional-dose group HVT ＋ CVI988 and 10× conventional-dose HVT ＋ CVI988 group were 26.6% and 26.7% respectively. The incidence of CVI988 vaccine group and HVT ＋ CVI988 combined vaccine group was lower than those in the HVT vaccine group. In short,the virulence enhancement due to wild strain variation had broken through the existing vaccine immune protection,thus bringing serious losses to the poultry industry.

关 键 词：超强马立克氏病毒 meq致瘤基因 疫苗 发病率 

分 类 号：S858.31[农业科学—临床兽医学]