中国动物检疫
中國動物檢疫
중국동물검역
CHINA ANMAL QUARANTINE
2015年
4期
14-17,31
,共5页
张康%龚振华%林祥超%郭光礼%杜翔%王丽萍%于建敏%李金平%侯广宇%单虎
張康%龔振華%林祥超%郭光禮%杜翔%王麗萍%于建敏%李金平%侯廣宇%單虎
장강%공진화%림상초%곽광례%두상%왕려평%우건민%리금평%후엄우%단호
超强马立克氏病毒%meq致瘤基因%疫苗%发病率
超彊馬立剋氏病毒%meq緻瘤基因%疫苗%髮病率
초강마립극씨병독%meq치류기인%역묘%발병솔
very virulent Marek's disease virus strain%meq gene%vaccine%incidence
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。
對從髮病鷄場分離到的一株超彊馬立剋氏病毒株，用PCR擴增該分離毒株的meq緻瘤基因併測定瞭其序列，髮現其與超彊病毒株SD2012-1的覈苷痠同源性為99%。該分離毒株的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箇堿基（CAC），與SD2012-1相同。使用該分離毒株進行疫苗免疫攻毒實驗，未免組的髮病率為80.0％，常規劑量HVT組和10×常規劑量HVT組的髮病率分彆為73.0％和76.6％，HVT不能提供有效免疫保護。常規劑量CVI988組和10×常規劑量CVI988組的髮病率分彆為30.0％和30.0％，常規劑量HVT+CVI988組和10×常規劑量HVT+CVI988組的髮病率分彆為26.6％和26.7％，免疫CVI988疫苗組鷄和HVT+CVI988聯苗組鷄的髮病率比免疫HVT疫苗組鷄低。說明，野外毒株的不斷變異已經突破現有疫苗的免疫保護，會給養鷄業帶來嚴重的損失。
대종발병계장분리도적일주초강마립극씨병독주，용PCR확증해분리독주적meq치류기인병측정료기서렬，발현기여초강병독주SD2012-1적핵감산동원성위99%。해분리독주적meq기인서렬재제575～577위비역묘주CVI988/Rispens적meq기인서렬다삽입3개감기（CAC），여SD2012-1상동。사용해분리독주진행역묘면역공독실험，미면조적발병솔위80.0％，상규제량HVT조화10×상규제량HVT조적발병솔분별위73.0％화76.6％，HVT불능제공유효면역보호。상규제량CVI988조화10×상규제량CVI988조적발병솔분별위30.0％화30.0％，상규제량HVT+CVI988조화10×상규제량HVT+CVI988조적발병솔분별위26.6％화26.7％，면역CVI988역묘조계화HVT+CVI988련묘조계적발병솔비면역HVT역묘조계저。설명，야외독주적불단변이이경돌파현유역묘적면역보호，회급양계업대래엄중적손실。
In this study,a very virulent Marek's disease virus(vvMDV) 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.
