畜牧兽医学报 ›› 2015, Vol. 46 ›› Issue (7): 1191-1200.doi: 10.11843/j.issn.0366-6964.2015.07.016

• 预防兽医 • 上一篇    下一篇

超强马立克病病毒株的致病性研究

龚振华1,张康1,2,王丽萍3,郭光礼4,李金平1,于建敏1,李蕾1,侯广宇1,王建琳2*,单虎2   

  1. (1.中国动物卫生与流行病学中心,青岛 266032;2.青岛农业大学动物科技学院,青岛 266109;3.青岛易邦生物工程有限公司,青岛 266032;4.山东临朐县畜牧局,临朐 262600)
  • 收稿日期:2015-04-03 出版日期:2015-07-23 发布日期:2015-07-23
  • 通讯作者: 王建琳(1976-),女,山西沁源人,副教授,博士,主要从事禽病发生机制的研究,E-mail:bjsxxw@126.com
  • 作者简介:龚振华(1968-),男,湖南岳阳人,副研究员,主要从事动物疫病诊断技术研究,E-mail:gzh1832@126.com,Tel:0532-85652282
  • 基金资助:

    山东省自然科学基金(ZR2013CL022);青岛市科技计划基础研究项目(11-2-4-5-<11>-jch)

Studies on Pathogenicity of a Very Virulent Marek’s Disease Virus Strain

GONG Zhen-hua1,ZHANG Kang1,2,WANG Li-ping3,GUO Guang-li4,LI Jin-ping1,YU Jian-min1,LI Lei1,HOU Guang-yu1,WANG Jian-lin2* ,SHAN Hu2   

  1. (1.China Animal Health and Epidemiology Center,Qingdao 266032,China;2.College of animal science and technology,Qingdao Agricultural University,Qingdao 266109,China;3.Qingdao Yebio Bioengineering Co.,Ltd,Qingdao 266032,China;4.Linqu Animal Husbandry and Veterinary Administration,Linqu 262600,China)
  • Received:2015-04-03 Online:2015-07-23 Published:2015-07-23

摘要:

拟对一株超强马立克病病毒(MDV)SD2012-1株的致病性进行研究。将60只SPF鸡平均分成未免组、HVT免疫组和CVI988疫苗免疫组3组。于1日龄时对其进行马立克病(MD)疫苗免疫,于10日龄时进行SD2012-1攻毒;每天观察攻毒鸡临床症状,对病死鸡进行病理剖检和组织学观察;用PCR反应对感染鸡进行MDV跟踪监测。病理学研究结果显示:攻毒后第2周,试验鸡有轻微组织病变;攻毒后第6周,试验鸡有眼观病变,镜检有散在的肿瘤细胞团块;攻毒后第9周,试验鸡有明显的眼观肿瘤病变,镜检有大量肿瘤细胞聚集;SD2012-1可以突破CVI988疫苗免疫,引起高达30%的鸡发病。PCR跟踪监测结果显示:攻毒后第5天,未免组和HVT免疫组可检出MDV;攻毒后第10天,未免组和HVT免疫组阳性检出率均为100%,CVI988免疫组阳性检出率为30%;攻毒后第20天,3组试验鸡阳性检出率均为100%;用PCR检测病死鸡的肝、肾、肌胃、肠系膜、十二指肠、心和法氏囊样品的结果均为MDV阳性;攻毒300 d后,健康存活鸡的羽髓PCR检测结果均为MDV阳性。结果表明,HVT疫苗对于SD2012-1株几乎无保护作用,超强马立克病病毒SD2012-1株能够长期在免疫鸡体内存在,突破免疫保护,引起发病,这对国内防控鸡马立克病提出了严峻挑战。

Abstract:

In this study,the pathogenicity of a very virulent Marek’s disease virus (MDV) SD2012-1 strain was analyzed.sixty SPF chickens were randomly divided into 3 groups:non-immunized group,HVT immunized group and CVI988 immunized group.Chickens were vaccinated with different types of MD vaccine at 1-day-old,and were challenged with SD2012-1 strain at 10-day-old.The challenged chickens were housed in separate isolators,and were sampled for clinic,histopathology and PCR detection of MDV.Clinical and histopathologic lesions in the infected chickens showed:slight histopathologic lesions were developed at 2 weeks post challenge,characteristic histopathologic lesions with scattered clumps of tumor cells were developed at the 6th weeks post challenge,and grossly obvious tumor lesions with large number of tumor cell aggregates were developed at the 9th weeks post challenge;SD2012-1 could break through the protection of CVI988 vaccine,causing MD with up to 30% rate in immunized chickens.PCR tracking of MDV in the infected chickens showed:MDV could be detected in non-immunized group and HVT group at 5 days post challenge;the positive rates of MDV were 100% in non-immunized and HVT group,30% in CVI988 group,at 10 days post challenge;the positive rates in the three groups were all 100% at 20 days post challenge;samples,including liver,kidney,muscular stomach,mesentery,duodenum,heart and bursa of Fabricius collected from clinical chickens,were all MDV positive by PCR,feather pulp samples collected from the infected living chickens were all MDV positive by PCR.When infected with MDV SD2012-1,chickens immunized with HVT hardly had protective effect on this virus,and the long-term existence of SD2012-1 in chickens immunized with CVI988 vaccine could break through its immune protection,which proposed a severe challenge for Marek’s disease prevention and control.

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