魚類病原性黏液細菌(Flexibacter columnaris)之研究

Studies on the Freshwater Fish Pathogenic Myxobacterium, Flexibacter columnaris

徐大全(Ta-Chuan Hsu) ； 郭光雄(Guang-Hsiung Kou)

《臺灣水產學會刊》 5卷2期 (1977/06) Pp. 41-54

https://doi.org/10.29822/JFST.197706.0004

摘要

1974年8月至1975年10月，由本省各地罹病之鰻、鯉、鯽、錦鯉、泥鰍與虹鱒等淡水養殖魚分離出23株淡水魚類病原菌F. columnaris。本研究檢討六種分離培養基(Cytophaga agar, Modified Ordal's agar, Modified Cytophaga agar, Modified Peptonized Milk agar, Lewin & Lounsbery's agar與Peptonized-Milk-Actidione agar)之分離效果，觀察分離菌在形態上、培養條件、生化學特性、藥劑感受性與人工感染試驗上之差異，得下述之結果：
（一）六種分離培養基都具分離效果，但以Modified Peptonized Milk agar之效果較佳。
（二）23株分離菌均由病魚之鰓及體表之患部分離，由內臟器官則未分離到本菌，但在組織切片上則觀察到本菌的存在。
（三）23株分離菌在形態、培養條件、生化學特性與藥劑感受性上幾乎呈現均一的結果，與過去之研究幾無差異。卽本菌為一種革蘭氏陰性，具屈曲運動性之長桿形黏液細菌(myxobacterium)。生長溫度為5~35℃。耐鹽度為0.5% NaCl以下，不產生子實體與微孢子囊。以Modified Hugh-Leifson method測對glucose之利用為弱發酵性，但以Simon & White's method，則不利用。
（四）本菌對chloramphenicol，tetracycline，oleandomycin，nalidixic acid，nitrofurantoin，novobiocin & sulfisoxazole具有感受性。
（五）人工感染實驗顯示本菌對泥鰍、鯉與鯽具有病原性，但對鰻則否。各種感染方式中以菌浴造成之死亡率最高。在致死時間上，鯉與鯽均較泥鰍為短。

並列摘要

Twenty three strains of pathogen of the etiological agent of columnaris disease, Flexibacter columnaris were successfully isolated from infected eel, common carp, color carp, crucian carp, loach and rainbow trout. The effectiveness of several isolation media were examined. It was found that the modified peptonized milk agar was the most suitable one. Although the pathogen could be observed in the sections of the liver and kidney, its isolation from these organs was unsuccessful. The biochemical and physiological characteristics of the present organisms were the same as that described by the previous investigators. However, the growth temperature for the present strains ranged from 5-35℃. Glucose fermentation was weakly positive after modified Hugh-Leifson method and negative after Simon and White's method respectively. However, the pathogen produced neither microcyst nor fruiting body. Seven out of ten antibiotics inhibited the growth of five randomly selected strains. The isolates showed pathogenicity to common carp, crucian carp, loach in artificial infection. However, artificial infections of eels had not succeeded.