Basic and practical studies on the immunological prevention of salmonids against bacterial diseases

研究了鲑科鱼类对鳗弧菌和杀鲑气单胞菌的保护性免疫机制.巨噬细胞的激活机制和巨噬细胞在保护中的作用：虹鳟鱼抗体产生与抗细菌感染的关系进行了研究。经福尔马林灭活菌免疫的鱼，虽然能抵抗强毒菌的攻击，但抗体滴度与保护力之间没有明显的关系。活鳗弧菌能引起虹鳟鱼腹腔巨噬细胞的强烈荧光反应。巨噬细胞的激活可能与虹鳟鱼的抗性有关. C-反应蛋白（CRP）的产生及CRP的保护作用：虹鳟鱼血清中CRP水平在细菌感染后显著升高。纯化的CRP激活虹鳟鱼的补体系统，并抑制细菌的体外生长。CRP水平也受水温的影响.虹鳟鱼对细菌内毒素的抵抗机制：虹鳟鱼血清中的内毒素含量高于哺乳动物。注射内毒素后，虹鳟鱼血清中内毒素含量显著增加，但未观察到临床异常，表明虹鳟鱼对内毒素具有较高的抵抗力。

Protective immune mechanisms of salmonids against fish pathogen Vibrio anguillarum and Aeromonas salmonicida were investigated.1. Mechanism of activation of macrophages and the role of the macrophages in protection: Relationship between antibody production in rainbow trout and resistance against bacterial infection was investigated. Though the fish immunized with formalin-killed bacteria resisted the challenge with virulent bacteria, there was no obvious relationships between antibody titer and protection. Living V. anguillarum elicited strong chemiluminescent reaction in peritoneal macrophages of rainbow trout. The activation of macrophages seemed to be related to the resistance of rainbow trout.2. Production of C-reactive protein (CRP) and the role of CRP in protection: CRP levels in rainbow trout sera increased significantly after bacterial infection. Purified CRP activated complement system of rainbow trout, and suppressed in vitro growth of bacteria. CRP levels were also affected by water temperature.3. Mechanism of resistance of rainbow trout against bacterial endotoxin: Rainbow trout serum was found to contain higher levels of endotoxin than mammals. Though the amount of endotoxin in serum increased significantly by the injection of endotoxin, no clinical abnormality was observed in fish, indicating that the rainbow trout possessed high resistance to endotoxin.