ヒラメ養殖場におけるEdwardsiella tardaおよびそのバクテリオファージの動態

Seasonal Appearance of Edwardsiella tarda and its Bacteriophages in the Culture Farms of Japanese Flounder

Matsuoka Satoru

Nakai Toshihiro

魚病研究

Fish Pathology

愛媛県下のヒラメ養殖場において、飼育環境水およびヒラメからのE. tardaとその溶菌ファージの出現動向を周年にわたり調べた。エドワジエラ症は6月から12月にかけて発生し、病気の発生とほぼ同時にE. tardaが環境水および外見上健康なヒラメから検出された。一方、ファージは病気発生の1か月以上前から環境水に高頻度に出現し、病気の終息とともに検出されなくなった。環境水におけるファージの出現は養殖場におけるE. tardaの存在の指標になると考えられた。

This study was conducted to investigate seasonal appearance of Edwardsiella tarda and E. tarda bacteriophages in cultured Japanese flounder Paralichthys olivaceus and the culture environment. The surveys were carried out twice a month at 4 commercial fish farms in Ehime Prefecture in 2002-2004. E. tarda was isolated from the environmental seawater and the organs (kidney and spleen) of apparently healthy fish from June to December when mortality due to edwardsiellosis was found among cultured populations. As expected, the outbreak of the disease preceded a rapid increase in the titers of serum agglutinins against E. tarda. In contrast, E. tarda phages were frequently identified in the environmental seawater at least one month before the disease outbreak and during the disease prevalence, but not detected after the outbreak terminated. The present study suggests that the appearance of E. tarda phages can be an indicator for existence of E. tarda in the culture environment.

Edwardsiella tarda

bacteriophage

epizootiology

Paralichthys olivaceus

edwardsiellosis

Fishing industry. Fisheries [ 660 ]

eng

日本魚病学会

Copyright (c) 2004 The Japanese Society of Fish Pathology

[ISSN] 0388-788X

[NCID] AN00063165