鸭源呼肠孤病毒对雏鸭致病性研究  

Pathogenicity of duck avian reovirus for Pekin ducklings

作　　者：张颖[1,2] 刁有祥[1] 高明 葛平萍[1] 孙晓艳[1] 鲁爱玲 

机构地区：[1]山东农业大学动物科技学院,山东泰安271018 [2]四川省绵阳农业学校,四川绵阳621000 [3]四川省绵阳市游仙区畜牧兽医局,四川绵阳621000

出　　处：《中国兽医学报》2015年第3期350-354,共5页Chinese Journal of Veterinary Science

基　　金：国家水禽产业技术体系资助项目(CARS-43-10)

摘　　要：30只10日龄樱桃谷肉鸭随机平均分为试验组和对照组,试验组静脉接种分离的鸭源呼肠孤病毒(DRV)SDWF株,每只0.2mL(ELD50=10-2.36/0.2mL),对照组每只静脉接种0.2mL生理盐水。于感染后3、6、9、12、15d每组随机抽取3只采血,利用流式细胞术分析外周血CD4+/CD8+比值变化,并测定血清中IL-6及INF-γ含量以及免疫器官指数,同时观察试验组鸭临床症状、剖检变化及病理组织学变化。结果显示,攻毒后3d,试验组雏鸭表现精神沉郁,食欲不振,生长发育缓慢,体质量下降。剖检变化表现为脾脏出血、肿大、坏死,肝脏坏死。病理组织学变化表现为脾脏、法氏囊淋巴细胞流失严重,网状纤维显现;脾脏坏死,形成肉芽肿,血管动脉管壁疏松、增厚。攻毒后3d,外周血CD4+/CD8+比值升高,随后于攻毒后6、9d开始迅速下降,显著低于对照组(P<0.05),后期虽有所回升,但是CD4+/CD8+比值仍然低于对照组;血清中IL-6及IFN-γ含量变化规律与外周血CD4+/CD8+比值变化规律相似,在攻毒后9d均显著低于对照组(P<0.05);胸腺、法氏囊指数均在攻毒后6d显著低于对照组(P<0.05),脾脏指数在整个试验观察期间高于对照组。结果表明,脾脏、法氏囊是雏鸭感染DRV的主要靶器官,免疫器官淋巴细胞流失严重,T细胞数量减少,IL-6、IFN-γ分泌量降低,从而导致机体免疫抑制。Fifteen ducklings for the experiment were inoculated with duck avian reovirus(DRV)SDWF strain with 0.2mL of the undiluted infective amnio-allantoic fluids(ELD50=10-2.36/0.2mL)which was isolated from duck through intravenous injection at 10-day-old.At the same time,fifteen ducklings were inoculated with sterile physiological saline in the same way as control group.Ducklings were regularly observed for clinical signs,and the following procedures were conducted for each group at 3,6,9,12 and 15days post inoculation.Blood was collected from three ducklings randomly selected from each group and the ratio of CD4+/CD8+was examined by flow cytometry.The serum was collected to examine IL-6and IFN-γlevels by ELISA kits,respectively.Moreover,necropsy lesions and histopathological changes were observed.Additionally,whole body weight,relative weights of immune organs,such as spleen,thymus and bursa were also investigated at 3,6,9,12 and 15days post inoculation.Results showed that all of 15 ducklings inoculated with reovirus showed depression and loss of appetite at 3days post inoculation.Ducklings appeared smaller than the control group.The pathohistology changes of ducklings after anatomy included spleen enlarged,haemorrhages,necrosis and more visible yellow focal necrosis were observed in liver.Histopathological results showed that the immune organs such as bursa and spleen performed significantly microscopic changes.Lymphocyte depletion was evident with reticular fiber visualized in bursa and spleen.The granuloma structure and necrotic foci were seen in the spleen and the artery of spleen showed homogenizing,swollen,sparsely,vacuolar degeneration in vessel wall,even occlusive.Indirectly flow cytometry results showed that the ratios of CD4+/CD8+increased at 3days post inoculation,then significantly decreased compared with controls at6,9days post inoculation.Although it increased later,the ratio of CD4+/CD8+still remained lower than that of control group.The regularity of IL-6and IFN-γshowed as same as CD4+/CD8+and were si

关 键 词：鸭源呼肠孤病毒 雏鸭 致病性 

分 类 号：S858.32[农业科学—临床兽医学]