Relationship between the occurrence of vibriosis in ayu (Plecoglossus altivelis) and freshwater amphipods (Jesogammarus annandalei) which migrate vertically in Lake Biwa.

日本琵琶湖由鳗弧菌引起的弧菌病几乎每年都会严重危害淡水鱼（鲑科）。这种病原体需要NaCl才能生长。当病原体暴露于经过消毒的陈年湖水中时，它在不失去呼吸活动的情况下失去了培养能力。虽然这种生理状态看起来像“VBNC”，但它们即使在宿主鱼体内也不能复苏。由于这些细胞完全失去了致病性，vbnc样状态可能正在走向死亡。黑暗、寒冷、厌氧等环境因素有助于病原菌在淡水中生存而不进入不可培养状态。从垂直迁移的淡水片脚类（Jesogammarus annandalei）等浮游生物样品中检测到可培养的V. anguillarum细胞。这表明淡水片脚类动物在沉积在海底沉积物上的鳗鲡弧菌感染最终宿主阿玉的过程中起着中间宿主的作用。

Vibriosis caused by Vibrio anguillarum seriously damages freshwater fish (Salmoniforms) almost every year in Lake Biwa, Japan. This pathogen requires NaCl for its growth. When the pathogen was exposed to sterilized aged lake water, it lost its culturability without loosing respiratory activity. Although this physiological state looks like "VBNC", they could not resuscitate even in host fish bodies. As these cells totally lost their pathogenicity, the VBNC-like state is probably on the way to death. Environmental factors such as darkness, coldness and anaerobiosis helped the pathogen to survive in freshwater without getting into nonculturable state. Culturable V. anguillarum cells were detected from planktonic samples such as freshwater amphipods (Jesogammarus annandalei), which migrate vertically. This indicates that freshwater amphipods have roles as intermediate hosts in the infectious process of V. anguillarum, which were deposited on the bottom sediments, to the final host, ayu.