口腔領域に於ける Corynebacterium に関する研究

Abstract

It has been present author's experience in the routine treatment of oral infectious diseases that the most frequent organisms encountered in the examination of certain cure-resistant diseases were those belonging to the genus Corynebacterium. Present knowledge of these organisms, however, seems to be very scanty so far as it concerned to the organisms to be found in the mouth and its environment. In view of this, a series of oral examination was undertaken on a total of 266 subjects consisting of healthy as well as patient individuals, and a total of 174 strains of corynebacteria was isolated from various sourses of the mouth for the subsequent microbiological study. The results obtained were summarized as follows. 1) The sourses from which the total number of strains was derived were as follows : 36 strains from 53 saliva specimens obtained from healthy individuals (68%), 56 strains from 69 cases of periodontal diseases (72%), 34 strains from 67 cases of various abscess (51%), 36 strains from 47 cases of root-canal infections (77%), 14 strains from 20 varied cases of serious diseases (70%) and 4 strains from 10 cases of dental caries (40%) 2) These isolates permitted themselves to be divided into 8 groups according to their different behaviors in fermenting carbohydrates. 3) They were further studied for the cultural characteristics using a variety of media including Clauberg' medium, Arakawa's medium, Omagari's C. T. M. medium, Loeffler's blood serum, blood agar medium, Levinthal's liver agar, glycerin agar, agar-agar and glucose-agar, as well as for other biological characteristics. The results of this study led to further subdivisions for the 1st and 2nd groups of the organisms, the former being divided into three types, the latter into two. 4) Of totally 174 strains isolated 119 could be classified into known categories of the bacterial nomenclature ; in the 1st group, namely, there were 82 strains of C. pseudodipht heriticum, in the 3rd group 13 strains of C. hoagii, in the 4th group 8 strains of C. xerose, in the 5th group 5 strains of C. acnes, in the 7th group 10 strains of C. pyogenes and in the last group one strain of C. renale. The remaining 55 strains did not conform to any classification so far described and were regarded as unidentified species. 5) It was noted, however, that of these 55 strains, 20 from the 2nd group were characteristic in that they fermented only levulose, whereas 17 strains from the 6th group fermented glucose, galactose, mannose, levulose and saccharose. The latter strains had reasons to be regarded as identical with the species previously described by Takamoto et al. 6) Besides the routine cultural and and sugar-fermenting characteristics, attention must be called to the hemolytic activity as observed in some strains of 6th and 8th groups, because it has been generally believed that the corynebacteria from oral origin usually lacked this activity. These organisms developed hemolysis either on rabbit blood or on human blood or on both simultaneously, in each case with varying intensity according to difference from one strain to another. Gram stainiug reaction of all the isolates was generally stable and was of little use for characterization. All the members in the 7th group and a part of the 8th group developed gelatin liquefaction.