1980 Volume 15 Issue 2 Pages 63-67
In the previous study (HORIUCHI et al., 1980), the species-specificity of direct immunofluorescence (IF) and the specific reactivity of labeled antibody on impression preparation from an artificially infected eel were confirmed.
In this study, the direct IF for rapid diagnosis of edwardsiellosis in eels was evaluated on field cases.
Fifty two cases of 25 outbreaks of bacterial disease in 19 eel farms were examined during the period from December, 1978 to February, 1980 (Table 1). Staining acetone-fixed impression preparations of liver and/or kidney with 4 units of FITC-labeled anti-E. tarda rabbit IgG was made, as well as cultures on nutrient agar. The preparations were examined with fluorescence microscope under UV excitation system and the pure cultures obtained were identified by their morphological and biochemical properties. The results obtained by direct IF were compared with culture results.
Of the 52 cases, 43 cases were positive and 9 negative by direct IF. The results of direct IF coincided with the culture results of E. trada (Table 2). In 12 cases of 43 cases where direct IF results were positive, both E. tarda and Aeromonas sp. were isolated. In 9 cases where direct IF results were negative, Vibrio sp. or Aeromonas sp. was isolated.
The above data indicated that we could employ direct IF on impression preparation for the rapid and accurate diagnosis of edwardsiellosis in eels.
