The Role of Extracellular Protease Produced by Vibrio anguillarum

Vibrio anguillarumの産生するプロテアーゼの役割

Kanemori Yoshifumi

Nakai Toshihiro

Muroga Kiyokuni

魚病研究

The role of protease in the pathogenicity of Vibrio anguillarum in experimental infections in Japanese eel (Anguilla japonica) and ayu (Plecoglossus altivelis), and its protective immunogenicity were investigated.

It was confirmed antigenically that the pathogen produced the same protease in the experimentally infected fish as in vitro, though proteolytic activity was not detected. Pre-treatments with a sublethal dose of the protease by intramuscular injection in eels or by immersion in ayu enhanced the susceptibility of the fish to V. anguillarum. When an eel serum was treated in vitro with 10-50 μg/ml of protease, the bactericidal activity of the serum was completely reduced.

The protective immunogenicity of protease was demonstrated when the antigen was given to eels and ayu by injections. However, efficacy of the protease vaccine was overridden by its toxicity when ayu were vaccinated and challenged by immersion method.

Vibrio anguillarum の病原機構におけるプロテアーゼの役割およびプロテアーゼの免疫病原性について検討した。V.anguillarum を感染させた魚の体内においてプロテアーゼ抗原の存在が確認された。ウナギおよびアユを予めプロテアーゼで処理することにより, V.anguillarum に対する魚の感受性が高められた。ウナギ血清の殺菌作用は10μg/ml以上のプロテアーゼで処理することにより非働化血清と同程度のレベルまで低下した。プロテアーゼで注射免疫したウナギおよびアユには感染防御効果が認められたが, 浸漬免疫したアユでは対照区より死亡率が高かった。

Zoology [ 480 ]

eng

日本魚病学会

Copyright (c) 1987 The Japanese Society of Fish Pathology

[ISSN] 0388-788X

[ISSN] 1881-7335

[NCID] AN00063165