广西三黄鸡禽白血病的净化及分离毒株致病性研究

发布时间：2018-05-04 15:11

本文选题：禽白血病 + J亚群禽白血病病毒　；参考：《广西大学》2017年硕士论文

【摘要】：禽白血病(avian leukosis,AL)是指由反转录病毒科禽反转录病毒属禽白血病病毒(avianleukosisvirus,ALV)引起的以禽类造血组织中一些细胞成分大量增生而导致的一类传染性肿瘤疾病。根据病毒包膜蛋白的抗原性差异、病毒干扰实验、宿主范围等生物学特性,ALV主要被分为A-J共10个亚群以及2012年新发现的K亚群。AL主要引起鸡群生长、产蛋率等生产性能降低以及肿瘤发生,同时还会引起感染鸡机体抵抗力下降和免疫抑制,给养殖业带来严重的经济损失。近年来各地方品系鸡群中不同程度的各亚群混合感染比较普遍,这不仅可导致致病性更强,还有可能造成病毒的重组,给AL的防控带来更大的挑战。目前还没有用于预防和治疗AL的有效疫苗和药物,疾病的防控主要是通过种群净化。广西是我国地方品种鸡资源最丰富的省份之一,有许多优良的地方品系已得到很好的繁育和商业开发利用,白血病的净化工作就显得非常重要。本研究选择比较有特色的地方优势品种三黄鸡为研究对象,选择目前生产量最大的DGGX4公司的三黄鸡配套系的A、B、C三个纯系的种群开展净化工作。实施以逐个个体检测以及淘汰阳性个体、选留阴性个体繁育,实施严格生物安全措施防止种蛋污染及其后代鸡的水平感染,杜绝疫苗污染等为主要措施的净化方案,经过8个世代的连续净化,A、B、C三个纯系种群母鸡样品ALV-p27抗原阳性率分别由零世代的44.36%、8.14%、7.9%下降至七世代的0.80%、0.91%、0.94%;公鸡分别由零世代的肛拭p27抗原阳性率45.36%、17.50%、15.45%下降至七世代的ALV分离阳性率1.46%、2.64%、1.64%;七世代时A、B、C三个系的ALV-A/B抗体阳性率分别下降至 4.34%、2.17%、3.26%,ALV-J 抗体阳性率也下降至 6.52%、5.43%、6.52%,净化工作有效,净化效果理想。课题通过利用临床病例分离获得的ALV对1日龄三黄鸡进行腹腔接种,研究J亚群ALV(ALV-J)单独感染及三个亚群ALV(ALV-M:ALV-A、ALV-B和ALV-J)混合感染的致病性。结果两组感染均成功复制到临床的发病,病鸡体型瘦弱且发育不良,鸡冠苍白,脚垫、肝脏、小肠浆膜、肾脏等处看到血管瘤,肝、脾肿大且表面有灰白色肿瘤结节,肾脏长出球型肿瘤。在鸡的生长发育上表现出不同程度的抑制,从第5周开始感染组鸡只的体重均极显著低于未感染对照组(P0.01);免疫器官的发育均受到影响,感染鸡胸腺比重在1W、5W、11W时均极显著低于未感染对照组(P0.01),法氏囊比重在1W时均显著高于未感染对照组(P0.05),脾脏比重在11W时均极显著高于未感染对照组(P0.01);感染组鸡只对NDV、AIV-H5和H9疫苗免疫的抗体应答均表现不同程度的抑制;病理组织学检查,肝组织间可见大量浸润的淋巴细胞和髓细胞样瘤细胞,肾脏肿瘤可见大量弥漫性增生的髓细胞样肿瘤细胞,胞浆高度嗜酸性;血常规指标检测显示,感染组的淋巴细胞数和白细胞数在21W时显著低于未感染对照组(P0.05),CD4+/CD8+T比值在11W时极显著低于未感染对照组(P0.01)。表明感染鸡的机体免疫功能均受到明显抑制,而且混合感染的抑制作用强于单独感染。
[Abstract]:Avian leukosis (AL) is a kind of infectious tumor disease caused by the large proliferation of some cell components in the avian hematopoietic tissue caused by the avian antiretroviral virus (avianleukosisvirus, ALV) of the antiretroviral family. According to the antigenicity difference of the virus envelope protein, the virus interference experiment, the host range Such as the biological characteristics, ALV is divided into 10 subgroups of A-J, and the newly discovered K subgroup,.AL, in 2012, mainly caused the growth of chicken group, the production performance of the egg production and the tumorigenesis, and also caused the decline of the resistance of the chicken body and the immunosuppression, which brought serious economic loss to the breeding industry. The mixed infection of different subgroups in different degrees is common, which not only leads to stronger pathogenicity, but also may cause the recombinant of the virus, which brings more challenges to the prevention and control of AL. There are no effective vaccines and drugs for the prevention and treatment of AL. The prevention and control of the disease is mainly through population purification. Guangxi is a local breed of chicken in China. In one of the most abundant provinces, many excellent local strains have been well bred and commercially exploited, and the purification of leukemia is very important. This study chose three yellow chickens, the most distinctive local dominant varieties, to choose the A, B, and C three of the three yellow chicken supporting lines of the most productive DGGX4 company. The purification work of the population of the pure line was carried out. The purification scheme was carried out by individual detection and elimination of positive individuals, the selection of negative individual breeding, strict biological safety measures to prevent the pollution of eggs and the horizontal infection of the offspring of the chickens, and the elimination of vaccine pollution as the main measures. After 8 generations of purification, A, B, and C were purified. The positive rates of ALV-p27 antigen in hens were decreased from 44.36%, 8.14%, 7.9% to 0.80%, 0.91%, 0.94% in the seven generation, respectively, and the positive rate of the p27 antigen was 45.36%, 17.50% and 15.45% from zero generation to 45.36%, 17.50%, and 15.45%, 1.46%, 2.64%, and 1.64%, respectively, and the positive rates of ALV-A/B antibody in A, B, and C lines were respectively under the generation of generations. To 4.34%, 2.17%, 3.26%, the positive rate of ALV-J antibody also decreased to 6.52%, 5.43%, 6.52%, the purification work was effective and the purification effect was ideal. Through the peritoneal inoculation of 1 day old three yellow chickens by using ALV isolated from clinical cases, the J subgroup ALV (ALV-J) and three subgroups of ALV (ALV-M:ALV-A, ALV-B and ALV-J) mixed infection were studied. Results all the two groups were successfully replicated to the clinical disease. The sick chicken was thin and dysplastic. The crest of the chicken, the pads, the liver, the small intestine serosa, the kidneys, and the kidney and other places saw the hemangioma, the liver, the splenomegaly and the grayish white tumor nodules, the kidney grew out of the ball type tumor. The growth and development of the chicken showed different degrees of inhibition, from fifth weeks. The weight of the chickens in the beginning of infection was significantly lower than that of the uninfected control group (P0.01), and the development of the immune organs were all affected. The specific gravity of the infected chicken thymus was significantly lower than that of the uninfected control group at 1W, 5W and 11W (P0.01). The specific gravity of the bursa of the Fabricius was significantly higher than that of the non infected control group (P0.05), while the proportion of the spleen was significantly higher than that of the non infected group (P0.05). Infection control group (P0.01); the antibody response of chickens infected with NDV, AIV-H5 and H9 was inhibited in varying degrees; histopathological examination revealed a large number of infiltrating lymphocytes and myeloid cell like tumor cells between the liver tissues, and a large number of diffuse proliferative myeloid tumor cells and highly eosinophilic cytoplasm in renal tumors. The routine test showed that the number of lymphocytes and the number of leukocytes in the infected group were significantly lower than that of the uninfected control group (P0.05) at 21W, while the CD4+/CD8+T ratio was significantly lower than that of the uninfected control group (P0.01) at 11W, indicating that the immune function of the infected chickens was significantly inhibited, and the inhibition of mixed infection was stronger than that of the isolated infection.

【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S858.31

【参考文献】