【摘要】 【目的】为诊断江西宁都某鸡场黄鸡发病原因。【方法】通过病理剖检、PCR检测确诊该鸡场黄鸡患马立克氏病，并对该病毒meq基因全序列进行PCR扩增、克隆、测序和序列分析。【结果】病鸡表现“劈叉”神经症状，剖检结果发现病鸡的心脏、肝脏和脾脏等器官表面均出现大小不一的灰白色结节，腺胃糜烂、出血。PCR鉴定结果为马立克氏病病毒（marek’s disease virus,MDV）阳性，随后对MDV的meq基因进行了扩增、克隆和测序，MDV meq基因全长为1 020 bp。与参考毒株相比，核苷酸和氨基酸同源性分别为98.8%～99.8%和97.1%～99.7%，存在9个氨基酸突变位点，其中有3段4-脯氨酸（PPPP）重复序列，2段发生（PPPP-PR/APP）氨基酸突变。【结论】该毒株与近年国内强毒株或超强毒株在同一分支上，且氨基酸突变基本相同，推测该分离毒株毒力至少为强毒株。研究为临床马立克氏病诊断提供理论依据，为分析MDV变异提供重要参考。更多还原

【Abstract】 [Objective] The study was conducted to diagnose the cause of yellow chicken disease in a chicken farm in Ningdu County, Jiangxi Province. [Method] Through pathological dissection and PCR testing, this experiment confirmed that the yellow chickens in the farm were infected with Marek’s disease. In addition, the full sequence of the meq gene of the virus was amplified, cloned, sequenced, and analyzed. [Result] The diseased chickens exhibited symptoms of “splitting” neurological disorder. Pathological examination revealed varying sizes of gray-white nodules on the surface of organs such as the heart, liver, and spleen, as well as glandular stomach erosion and bleeding. PCR identification confirmed positive for Marek’s disease virus(MDV). The full length of MDV meq clone gene was 1 020 bp with nucleotide identities ranging from 98.8% to 99.8% and amino acid identities ranging from 97.1% to 99.7%. There were nine mutations in amino acid in meq genes, with three mutations in proline-rich repeat sequences(PPPP) and two PPPP-PR/APP mutations. [Conclusion] This strain belongs to the same branch as recently highly virulent or very virulent strains found domestically, showing similar amino acid mutations. Therefore, it is inferred that this isolated strain is at least a highly virulent strain in pathogenicity. This study provides a theoretical basis for clinical diagnosis of Marek’s disease and an important reference for analyzing MDV variations.更多还原