无乳链球菌感染尼罗罗非鱼的脑膜炎模型  

Oreochromis niloticus model of meningitis in Streptococcus agalactiae infection

作　　者：崔静雯[1] 汪开毓[1] 贺扬[1] 陈德芳[2] 黄小丽[2] 王均[1] 龙波[1] 张丽杰[1] 蒋洁[1] 

机构地区：[1]四川农业大学动物医学院,四川成都611130 [2]四川农业大学动物科技学院,四川成都611130

出　　处：《水产学报》2015年第12期1883-1893,共11页Journal of Fisheries of China

基　　金：教育部"长江学者和创新团队发展计划"(IRT0848);四川省科技厅产业链(2014NZ003);四川省科技厅应用基础专项(2014JY0143)~~

摘　　要：针对尼罗罗非鱼无乳链球菌病的致病机制,本实验建立了无乳链球菌感染尼罗罗非鱼致脑膜炎的模型,并制定相应的临床症状及组织病理学评分系统对其进行了研究。将43尾健康尼罗罗非鱼随机分为4组：对照组（n=10）和3个实验组（n=33）。3个实验组根据不同感染剂量分为1.0×10^6cfu组（n=11）、1.0×10^7cfu组（n=11）和1.0×10^8cfu组（n=11）。实验组分别将1.0×10^6、1.0×10^7和1.0×10^8cfu的无乳链球菌菌液腹腔注射尼罗罗非鱼复制脑膜炎模型。对感染尼罗罗非鱼的临床症状、剖检病变、脑组织（端脑、中脑、小脑、延脑）病理学进行判定,并结合细菌学检测,按照拟定的评分系统评价各组脑膜炎的造模效果,确定最佳造模方案。各实验攻毒组尼罗罗非鱼感染后2 d均出现不同程度死亡,未见明显神经症状。感染3d后鱼体开始出现异常活动的神经症状及突眼、角膜混浊等病理变化。病理组织学观察可见：蛛网膜下腔和脑软膜上有大量炎性渗出和染成蓝紫色微细颗粒的细菌团块,脑膜充血、水肿、疏松、增厚,有大量的中性白细胞等炎性细胞浸润;脑实质部基质疏松水肿,呈海绵状;脑组织炎性细胞浸润,胶质细胞增生等软脑膜炎、脑膜脑炎症状。比较各组得分发现,1.0×10^7cfu组的无乳链球菌攻毒尼罗罗非鱼造模效果最好：临床症状显著而组内尼罗罗非鱼差异性最小,组织病理学观察患病尼罗罗非鱼病情和缓适中、利于观察研究。综上,使用1.0×10^7cfu无乳链球菌腹腔攻毒尼罗罗非鱼可在第3天成功构建脑膜炎模型,造模率为100%。The meningitis was the characteristic clinical manifestation in Nile tilapia（ Oreochromis niloticus）infected by Streptococcus agalactiae.To knowthe degree and extent of inflammation as well as the presence of necrosis in the brain,we build an intraperitoneal infection model and develop a newclinical and histopathological scoring system for S.agalactiae in Nile tilapia.43 healthy nile tilapias,were randomly divided into 4 groups： control group（ n = 10）,lowdose group： 1.0×10~6 cfu group（ n = 11）,middle dose group： 1.0×10~7 cfu group（ n = 11）,high dose group： 1.0× 10~8 cfu group（ n = 11）.Clinical symptoms and cerebral histopathological changes（ cerebrum,optical lobe,cerebellum and medulla oblongata included） was oberserved in our study,we scored these three groups and obtained the best one.The infected nile tilapia died in second day post infection,however,neurological symptoms were not apparently observed in the dead fish.Survivors developed constant aberrant swimming,exophthalmia and corneal opacity.According to microscopical examination of four regions of the brain,large amount of bacteria stained bluish violet colonized the subarachnoid space and cerebral pia mater.Histopathology revealed the changes of leptomeningitis and meningoencephalitis,including congestion / hemorrhage,edema,loose and thickening in meninges,inflammatory cell neutrophilic leukocytes infiltration,superficial periplast of brain inflammatory cell infiltration and lysis spongy- structure,gliocyte hyperplasiain,and so on.Compared with the scores,we found that the group of 1.0×10~7 cfu was the best dosage,which showed significant clinical symptoms,the minimum diversity value and the condition of the sick fish contributed to the observational study.We chose the dose of 1.0×10~7 cfu to inject nile tilapia intraperitonealy to develop a model of S.agalactiae meningitis with the 100% success rate on the third day post infection.

关 键 词：尼罗罗非鱼 无乳链球菌 脑膜炎 模型 

分 类 号：S941[农业科学—水产养殖]