超强马立克氏病病毒的鉴定及病毒Meq基因序列的比较

Identification and Meq gene analysis of a very virulent Marek's disease virus strian

对1例感染超强马立克氏病病毒的病例进行确诊,对感染病毒的Meq基因进行比较分析。采用病理解剖、PCR检测、病毒分离、动物试验和Meq基因序列分析,对感染病毒进行研究。病理解剖结果为病死鸡的肝脏、脾脏、腺胃、肌胃、十二指肠表现为肿瘤病变。PCR检测结果为病死鸡的组织病料感染马立克氏病病毒。病毒分离和动物试验结果证明该感染病毒是1株马立克氏病超强毒株,该病毒可以引起免疫过CVI988疫苗的鸡发病。Meq基因序列分析表明该病毒与7株马立克氏病病毒参考毒株的同源性为98.8%~99.6%,该病毒在Meq的第115、119和176位氨基酸突变同国内流行株,该检测病毒在Meq的第217位氨基酸突变同超超强马立克氏病毒株。结果表明,通过病理解剖、PCR检测、基因序列分析、病毒分离和动物试验,确诊病鸡感染超强马立克氏病病毒。

To diagnose a case of chicken infected suspiciously with a very virulent Marek＇s disease virus（MDV） and to analyze the mutation of the Meq gene of the virus. In this study,necropsy for pathologic change, PCR detection for MDV, challenge with the isolated virus against the immunized chickens and analysis of the virus Meq gene were carried out. Pathologic changes in the infected chicken showed tumour lesions of organs （including liver, spleen, proventriculus and Duodena）. PCR detection for virus showed that the infected chicken was caused by MDV. The detected MDV was isolated,and could be a very virulent strain （vv MDV） ,and its pathogenicity to chickens immunized with CVI988 vaccine was displayed in animal challenge test. The Meq gene nucleotide of detected MDV had 98.8%-99.6% homology with 7 MDV reference strains. Like other MDV very virulent isolates in China,the detected MDV had the same mutations in the 115th,119th and 176th amino acid of Meq,and like the MDV very very virulent isolates （vv＋ MDV） ,the detected MDV had the same mutations in the 217th amino acid of Meq. An very virulent MDV was identified in an infected chicken. PCR detection, virus isolation, animal test and analysis of the virus Meq gene.