抄録
A total of 164 strains originally regarded as NAG vibrios were studied. Of them, 12 were excluded by preliminary biochemical tests based on the description of the genus Vibrio proposed by the IAMS Subcommittee on Taxonomy of Vibrios, because they were glucose oxidizers, gas producers from glucose, glucose non-fermenters, or oxidase-negative bacteria. Two and 8 strains were also excluded as of Vibrio parahaemolyticus and Plesiomonas shigelloides, respectively. The remaining 142 strains were regarded as vibrios, because they were monotrichously flagellated, oxidase-positive rods which fermented glucose without gas, and were subjected to numerical analysis by Adansonian concept and determination of the base composition of the DNA.
The 142 strains were divided into 2 biotypes from their physiological and biochemical characteristics. Of the 2 biotypes, biotype 10311 gave positive lysine and ornithine tests, but negative arginine test : produced acetoin from glucose ; produced acidity from citrate and mucate in Kauffmann-Petersen's broth ; gave positive cholera red test ; and were sensitive to vibriostatic substance and novobiocin. These characteristics were identical with those of the genus Vibrio. The percent content of guanine plus cytosine of the DNA of the biotype was 44.8, a value close to that reported for the known Vibrio spp.
On the other hand, the second biotype 6332 was different from biotype 10311 in the tests mentioned above. The content of guanine plus cytosine of the DNA was 62.0 in this biotype. These results indicated that biotype 6332 was of anaerogenic aeromonads, known as Aeromonas formicans or A. caviae.
These conclusions were also confirmed by means of numerical analysis. In addition, 5 strains of V. cholerre biotype eltor which were employed for comparison, were associated with the majority of the strains of biotype 10311 at a high level of over 90 % S value. From the results of both orthodox and numerical classification, the authors suggested that biotype 10311 should be placeed in the same species, V. cholerae, as the true cholera vibrios and El-Tor cholera vibrios.
The authors also suggested that revision should be made in the proposed description of the genus Vibrio recommended by the JAMS Subcommittee on Taxonomy of Vibrios, so that several biochemical characteristics may be added to it to differentiate the Vibrio spp. from the anaerogenic Aeromonas, Plesiomonas, and related bacteria.
When 10 strains of biotype 10311 and 5 of biotype 6332 were inoculated into the gut of the infant rabbit, all of the former produced diarrhea similar to that caused by the cholera vibrio, but none of the latter did.
