Outbreaks of bacterial gill disease (BGD) occurred among cultured rain
bow trout (Oncorhynchus mykiss) in Chungbuk province of Korea. Gram-ne
gative, filamentous and yellow-pigmented bacteria were isolated from t
he diseased fish. The morphological, physiological, biochemical, and a
ntigenic properties of the Korean isolates were consisted with those o
f Flavobacterium branchiophilum (ATCC 35035(T) and ATCC 35036) isolate
d from salmonid fish in Japan and Oregon, USA. It was concluded that t
he Korean isolates were identified as F. branchiophilum.