ALV-J与REV共感染对肉鸡的致病作用及继发大肠杆菌的多样性研究

发布时间：2018-03-16 16:36

本文选题：REV　切入点：ALV-J　出处：《山东农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：J亚群禽白血病病毒(ALV-J)和禽网状内皮组织增生症病毒(REV)均是可以引起鸡体产生免疫抑制和肿瘤性疾病的反转录病毒。ALV-J首次于1988年发现,能够引起肉用型鸡的肝脾肿大和器官表面肿瘤。在过去的十年里,ALV-J已经给养禽业带来了巨大的经济损失。前人研究发现,鸡群中多种肿瘤性病毒共感染的现象普遍存在,尤其是REV和ALV-J的共感染。本实验室经过多年动物实验观察和总结,发现多种免疫抑制病病毒的单独感染和共感染能够引起典型的心包炎和腹膜炎。禽大肠杆菌病既可以是鸡的原发性疾病,又可能成为支原体和病毒感染以及其他环境因素的继发性疾病,能造成鸡群的高发病率和死亡率,高璐等人研究了低致病性禽流感与大肠杆菌的协同致病作用,发现MPAIV和E.coli之间在致病性上有协同作用,而这可能是由于MPAIV的感染导致鸡群产生一定程度的免疫抑制,从而进一步促进了E.coli在体内的定居和繁殖。本实验对ALV-J和REV共感染对肉鸡的致病作用以及病毒继发大肠杆菌的多样性进行了研究。1、ALV-J和REV共感染对肉鸡致病性的研究本实验系统研究了ALV-J和REV共感染对商品代肉鸡的致病作用。选择1日龄健康商品代罗斯308肉鸡作为实验对象,将雏鸡随机的分为5个小组:REV单独感染组、ALV-J单独感染组、REV+ALV-J(大剂量组)、REV+ALV-J(小剂量组)和空白对照组。7日龄时,所有鸡只免疫新城疫(NDV)和禽流感(AIV-H9)疫苗各0.2ml。在免疫接种后第3、4和5周采集血清用于检测鸡体对于NDV和AIV-H9疫苗免疫后的抗体反应水平。在42日龄时,各组选取18只鸡进行剖杀,分别取其胸腺、脾脏和法氏囊进行称重并计算免疫器官指数。饲养到第6周,记录死亡率并对病死鸡进行剖检。试验结果显示,ALV-J和REV共感染组与单独感染组相比,能够引起更为显著的生长迟缓和免疫抑制(P0.05),免疫抑制主要体现在共感染组中显著降低的胸腺指数和法氏囊指数以及显著降低的对NDV和AIV-H9疫苗的抗体反应水平(P0.05)。而关于病毒感染继发的大肠杆菌情况发现,共感染组继发大肠杆菌的死亡率明显高于其他各组(P0.05)。以上结果表明,ALV-J和REV的共感染对商品代肉鸡具有协同致病作用。2、免疫抑制性病毒共感染继发大肠杆菌的多样性研究为了解免疫抑制性病毒感染肉鸡群后继发大肠杆菌的血清型及其耐药性的多样性,本研究对两次ALV-J和REV共感染肉鸡的重复试验中剖检发现有典型的肝周炎和心包炎的鸡,应用麦康凯培养基进行细菌分离培养。每个炎变脏器各随机挑取5个红色菌落或(及)白色菌落,并分别进行生化试验、血清型鉴定和药敏实验。试验结果显示,从58只呈现典型肝周炎或(和)心包炎的死亡鸡中分离到的516个菌落,经常规生化鉴定均为大肠杆菌。O抗原血清型鉴定结果显示,这516个大肠杆菌属于12种不同的血清型。来自同一病鸡、同一脏器且经鉴定为同一血清型的5个菌落定义为一组菌落,从516个大肠杆菌中挑选的17组进行试管药敏试验,结果表明,第3组的5个菌落对粘杆菌素的最小抑菌浓度的范围为0.05 mg/ml-51.20 mg/ml;第17组菌落对丁胺卡那的最小抑菌浓度从0.05 mg/ml到51.20 mg/ml,均相差1000倍。综上结果说明病毒诱发的肝周炎和心包炎中分离到的大肠杆菌在血清型和耐药性方面都存在着高度多样性。
[Abstract]:Avian leukosis virus subgroup J (ALV-J) and Avian Reticuloendotheliosis Virus (REV) is the chicken can cause immune suppression and tumor disease retrovirus.ALV-J was first discovered in 1988, meat type chickens can cause hepatosplenomegaly and organ surface tumor. In the past ten years, ALV-J has been. The poultry industry has brought huge economic losses. Previous studies found that widespread tumor virus co infection of chickens in the phenomenon, especially the co infection of REV and ALV-J. The animal experiment laboratory after years of observation and summary, found that a variety of immunosuppressive disease virus infection and co infection can cause typical pericarditis and peritonitis. Avian colibacillosis can be chicken primary disease, and may become a secondary disease of Mycoplasma and viral infections and other environmental factors, can cause high incidence of chickens And death rates, Gao Lu et al studied the synergistic effects of low pathogenic avian influenza and Escherichia coli, found between MPAIV and E.coli in pathogenicity have a synergistic effect, which may be due to MPAIV infection in chickens immune have a certain degree of inhibition, so as to promote the E.coli in vivo colonization and reproduction. The experiments of ALV-J and REV co infection diversity of pathogenic effects on Broilers and secondary virus in Escherichia coli was studied by.1, ALV-J and REV co infection of pathogenic effects on broiler pathogenic the experimental system of ALV-J and REV co infection of broiler chickens. The choice of Ross 308 broilers were used as experimental the 1 day old health goods, will chickens were randomly divided into 5 groups: REV infected group and ALV-J infected group, REV+ALV-J (high dose group), REV+ALV-J (low dose group) and blank control group at.7 days of age, the Some chickens were immunized with Newcastle disease (NDV) and avian influenza (AIV-H9) vaccine immunization in 0.2ml. 3,4 and 5 weeks after collection of serum for detection of chicken for antibody response levels of NDV and AIV-H9 after vaccination. At the age of 42 days, each group selected 18 chickens were killed, were taken from the chest gland, spleen and bursa were weighed and calculated the index of immune organs. Feeding to sixth weeks, and mortality was recorded on autopsy of dead chickens. The test results show that the ALV-J and REV co infection group and infected group compared to lead to growth retardation and immunity significantly inhibited (P0.05), the main immune suppression reflected in the co infection of thymus and bursa index were significantly reduced and a significant reduction of NDV and AIV-H9 vaccine antibody response level (P0.05). A virus infection of Escherichia coli of secondary infection group were found secondary mortality of Escherichia coli Was significantly higher than other groups (P0.05). These results indicate that ALV-J and REV co infection of broiler chickens has synergistic effects of.2, inhibit the immune diversity of secondary infection of Escherichia coli in order to understand the immune suppression infection and antibiotic resistance of broilers serum after secondary Escherichia coli diversity of viral virus, have typical perihepatitis, pericarditis chickens found repeated tests in this study were infected chickens for two times ALV-J and REV in the application of Makanke medium for bacterial culture. Each inflammatory organ each randomly selected 5 red colonies or (and) white colonies were biochemical test, serotype identification and the drug sensitivity test. Test results show that from 58 typical parahepatitis or (and) 516 colonies isolated from dead chickens in pericarditis, conventional biochemical identification for Escherichia coli.O antigen serotype identification The results showed that 516 Escherichia coli belonging to 12 different serotypes. From the same disease of chicken, the same organ and identified 5 colonies were defined as the same serotype as a group of colonies, 17 groups of in vitro drug sensitivity test, selected from 516 Escherichia coli. The results showed that 5 a colony of third groups of minimal inhibitory concentration of colistin in the range of 0.05 mg/ml-51.20 mg/ml; seventeenth groups of colonies that butylamine card minimum inhibitory concentration from 0.05 mg/ml to 51.20 mg/ml, are 1000 times the difference. These results illustrate the isolated virus induced pericarditis and perihepatitis in Escherichia coli is highly diversity the serum type and drug resistance.

【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S858.31

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