摘要
2003年国内某火鸡场发生了一种以侵害15～25日龄雏火鸡为主的急性传染病，主要表现为腹泻，十二指肠、直肠充血和出血，盲肠肿大，肠道内充满黄绿色内容物，死亡率约为10％～20％。取病死火鸡肝、脾、肠匀浆，取上清液通过尿囊腔接种15日龄SPF鸡胚。连续传代至第5代，收集接种后72h内死亡或存活鸡胚的卵黄和肠道，用于病毒分离和提纯。试验中发现该病毒能凝集兔红细胞，不能凝集鸡红细胞。经电镜观察，在病毒提纯液中发现有圆形或椭圆形、带花冠状纤突的病毒粒子，初步诊断为火鸡冠状病毒感染。进而设计针对火鸡冠状病毒S2基因引物，进行RT-PCR扩增，结果扩增出预期大小的片段。运用所分离病毒进行动物回归试验，感染火鸡出现与自然病例一致的临床症状和病理变化，并能从发病火鸡分离出该病毒。以上结果表明所分离的病毒为火鸡冠状病毒。此病毒的分离在国内尚属首例。
An acutely infectious disease was encountered in turkey poults of 15-28 days old at a turkey farm in 2003. The affected birds presented with diarrhoea, the hyperaemia and hemorrhage of duodenum and rectum, cecum tumescence, intestines filled with yellow contents and 10% to 20% mortality. Livers, spleens and intestines obtained from died poults were homogenized and centrifuged. The supernatant was inoculated into 15-day-old specific pathogen free （SPF） embryonated chicken eggs to propagate the viruses. After 5 successive passages, the yolk and intestine of infected chicken embryos were harvested and homogenized 72 hours post-inoculation, for determining viral hemagglutination and purifying the viruses. The isolate had the ability to hemagglutinate erythrocytes from rabbit but not from chicken, and several spherical or oval viral particles with corona were observed by electron microscopy, which indicated the isolated viruses may be turkey coronaviruses. Furthermore, TCV S2 gene was amplified from the extracted total RNA of infected chicken embryos intestines by reverse transcription-polymerase chain reaction （RT-PCR） with designed primers, and the products were identical with the expectation. In addition, 3 days after 1-day-old turkey poults were orally inoculated with 1 mL of the intestine homogenate of the infected chicken embryos, the infected birds showed the same clinical signs and pathological changes as natural infected cases described above. Above results showed that the isolated viruses were turkey coronaviruses. It is the first time that coronaviruses were isolated from turkey in China.
出处
《畜牧兽医学报》
CAS
CSCD
北大核心
2006年第11期1241-1244,共4页
ACTA VETERINARIA ET ZOOTECHNICA SINICA
关键词
火鸡
冠状病毒
病毒分离
初步鉴定
turkey
coronavirus
virus isolation
preliminary identification
