鰤鱼诺卡氏菌感染乌斑杂交鳢的组织病理学研究

A Histopathological Study of Nocardia seriolae Infection in Hybrid Snakehead

人工养殖乌斑杂交鳢(Channa maculate♀×C.argus♂)受鰤鱼诺卡氏菌(Nocardia seriolae)侵害日益严重,为深入研究该菌的致病机理,鰤鱼诺卡氏菌感染乌斑杂交鳢的感染模型亟待建立。本研究通过对菌液浓度与吸光值、半致死剂量、组织病理学和病理组织切片等方面进行研究。结果表明菌液浓度为4.75×10^4~4.75×10^7 cfu/mL范围时与其吸光值呈线性关系。通过人工感染实验,确定鰤鱼诺卡氏菌感染乌斑杂交鳢的半致死剂量(LD50)为1.52×10^5 cfu/尾。组织病理学分析发现,鰤鱼诺卡氏菌感染乌斑杂交鳢会引起皮肤溃烂、内脏器官肿大,形成白色结节。病理组织切片显示,结节中心呈干酪样坏死,周围有大量细胞浸润。研究结果为建立鰤鱼诺卡氏菌感染乌斑杂交鳢的动物模型及研究鰤鱼诺卡氏菌致病机制提供科学依据。

The cultured hybrid snakehead(Channa maculate♀×C.argus♂)were increasingly suffered from Nocardia seriolae infection.In order to further study the pathogenic mechanism of N.seriolae,the infection model of N.seriolae infected with hybrid snakehead must be established.In this study,we studied the concentration and absorbance value,median lethal doses,histopathology and pathological sections.The result showed that a linear relationship between the absorbance and the concentration of N.seriolae was found within the range of 4.75×10^4~4.75×10^7 cfu/mL.The median lethal doses(LD50)was determined to be 1.52×10^5 cfu/fish by the experimental infection of N.seriolae in hybrid snakehead.Histopathological analysis revealed that N.seriolae infection caused skin ulceration,visceral swelling and white nodules.Histopathological section showed that the nodules were composed of a central zone with caseous necrosis,surrounded by a large number of infiltrating cells.The results laid the foundation for establishing the animal model of N.seriolae infected with black spot snakehead,and studying the pathogenic mechanism of Nocardia.