Pathogenic Vibrio Isolated from Cultured Eels—III

NaCl Tolerance and Flagellation

Abstract

The preceding papers(MUROGA et al., 1976 a, b)dealt with the biochemical characteristics, taxonomical status, physiological characters and pathogenicity of Vibrio sp. isolated from a new eel vibriosis.
In this paper the effect of NaCl concentrations of cultrue media on the NaCl tolerance and on the flagellation of the vibrio were examined, and these two characters of the organism were reconsidered by way of comparison with those of Vibrio fischeri.
The experimental results together with considerations are given as under.
1) NaCl tolerance : The lower limit falled to 0.1% after consecutive culture in the media containing 0.3% NaCl. The upper limit, in contrast with this, raised to 6% in case of the media with 4% NaCl. The range of 0.1 to 6% is applicable to the NaCl tolerance range of this organism in view of these results.
2) flagellation: Cells having more than one flagellum at one pole occurred in cultures grown on nutrient agar plate, of which the higher the NaCl concentration (0.5-4.5%), the higher the percent occurrence (0.22-20%). Cells, however, had one polar flagellum in cultures grown in nutrient broth except in the broth with extremely high concentration (4%) of NaCl. Accordingly it may be safely said that the flagellation of this organism is monotrichous.
In conclusion it is impossible to differentiate this organism provisionally classified as Vibrio anguillicida BRUUN and HEIBERG in the previous report (MUROGA et al., 1976a) from Vibrio fischeri in terms of the above-mentioned two characters.