• Korean Journal of Veterinary Research
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• v.38 no.2
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• pp.371-378
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• 1998

Five strains of gram-negative and yellow-pigmented bacteria were recently isolated from diseased freshwater fishes in Korea. All isolates were confirmed as a known fish pathogen of columnaris disease, Cytophaga columnaris based on their colonial and cellular morphology, and on physiological, biochemical and antigenic characteristics. Although the isolates were from different fish species, their characteristics of them were very similar to those of the reference strains of C columnaris (NCMB $2248^T$ and EK 28). Also, profiles of OMPs of Korean isolates were similar to those of the reference strain, C columnaris NCMB $2248^T$ when analyzed by SDS-PAGE.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.4
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• pp.369-373
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• 1985

The characteristics of a pathogen isolated from infected tilapia, which showed the external symptoms of fin erosion and body deceleration, were examined. The strain of isolated pathogen was identified as Flexibactor columnaris, The normal tilapia dipped into suspensions of the isolated pathogens has developed the infective symptoms. The strain of Flexibactor columnaris was sensitive to kanamycin, tetracycline, and amikacine, but resistant against sulfa drugs. This strain could not grow in the cytophaga media containing over $2\%$ NaCl or over $50\%$ sea water. In cytophaga broth containing more than $50\%$ or sea water instead of distilled water, the number of Flexibacter columnaris decreased from about $10^6/ml\;to\;10^4ml$ within one hour after inoculation. On the other hand, in cytorhaga broth containing more than $5\%$ of NaCl, the number rapidely reached less than 10/ml from about $10^5/ml$ within one hour after inoculation.