贝氏隐孢子虫对不同免疫状态雏鸡的致病性比较研究  

Comparison of the pathogenicity of Cryptosporidium baileyi in infected chickens with different levels of immunity

作　　者：齐萌[1] 黄磊[1] 高庚渠[1] 张素梅[1] 刘扬科[1] 徐利纳[1] 王荣军[1] 菅复春[1] 张龙现[1] 宁长申[1] 

机构地区：[1]河南农业大学牧医工程学院,河南郑州450002

出　　处：《中国病原生物学杂志》2010年第3期173-176,183,F0004,共6页Journal of Pathogen Biology

基　　金：国家自然科学基金资助项目(No.30371863)

摘　　要：目的了解贝氏隐孢子虫对不同免疫状态雏鸡的致病特点。方法采用中药黄芪溶液自由饮用(免疫增强组)和醋酸地塞米松片经口灌服(免疫抑制组)2 d龄雏鸡,连用5 d,于3d龄分别接种1×106个卵囊/只,观察其排卵囊情况、症状、组织病理学变化和脾脏及法氏囊指数。实验设感染对照组(不用药)和空白对照组。结果感染对照组、免疫增强组和免疫抑制组雏鸡感染隐孢子虫后的潜隐期均为4 d,开放期分别为24、24和26 d,发病雏鸡分别为10、3和15只,排卵囊(OPG)最大峰值分别为39.4×104、19.4×104和46.0×104;观察期3组雏鸡平均增重274、272和210 g/只,差异无统计学意义(P>0.05),脾脏和法氏囊指数免疫抑制组低于其他试验组,免疫增强组与空白对照组基本一致,感染对照组雏鸡脾脏指数与其他试验组比较差异较大。结论贝氏隐孢子虫对不同免疫状态雏鸡的致病性存在差异,中药黄芪对雏鸡感染隐孢子虫具有一定保护作用,免疫抑制剂可导致雏鸡感染隐孢子虫后症状加重。Objective To understand the characteristics of Cryptosporidium baileyi pathogenicity in infected chickens with different levels of immunity.Methods The Chinese herbal medicine astragalus and dexamethasone were given to 2-day-old chickens for five days by free access to drinking water and intragastric administration,respectively.Three-day-old chickens in groups with different levels of immunity were inoculated with 1×106 oocysts.Differences in pathogenicity were assessed according to the following aspects： oocyst shedding,clinical symptoms,histopathological changes,and immune organ index.An untreated infected group（no drug was used） and healthy control group were used in this study.Results After the chickens were inoculated with C.baileyi,the latent period was 4 days for the untreated infected group,immunoenhanced group,and immunosuppressed group.In contrast,the patent period was 24,24,and 26 days for these groups,respectively.The number of affected chickens was 10,3,and 15 for the three infected groups.The peak of oocyst shedding was 39.4×104,19.4×104,and 46.0×104,respectively.During the period of observation,the average increase in body weight was respectively 274 g,272 g,and 210 g per bird for the three groups;the difference was not statistically significant（P0.05）.However,the immune organ index of chickens in the immunosuppressed group was lower than that of all of the other experimental groups.In contrast,the immune organ index of the immunoenhanced group and the healthy control group was essentially the same;there were obvious difference in the spleen index of the untreated infected group and the other infected groups.Conclusion There were pathogenic differences in chicken with different levels of immunity infected with C.baileyi.The Chinese herbal medicine astragalus protected chickens after infection with C.baileyi,and an immunosuppressive agent heightened symptoms after infection with Cryptosporidium.

关 键 词：贝氏隐孢子虫 免疫 致病性 雏鸡 

分 类 号：R382.3[医药卫生—医学寄生虫学]