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T Ooshima

Publications and source records attributed to T Ooshima.

At least 127 records · Page 7Linked to original sources
PubMed1980

Changes in some biological properties of Streptococcus salivarius isolates from infected rats.

Isolation of colonies with altered colonial morphology was frequently observed following infection of specific pathogen-free rats fed a caries-inducing high sucrose diet with two human strains of Streptococcus salivarius. These isolates produced unique rough colonies on mitis salivarius agar, in contrast to the smooth, mucoid colonial morphology of the parental strain. The rough variants were characterized by a marked increase in the synthesis of polysaccharide from sucrose, especially cell-associated water-insoluble glucan, whereas the smooth parental strains mainly produced cell-free fructan. Glucose-grown cells of rough variants but not smooth parental strains were aggregated upon addition of sucrose. Such variants were not detected during laboratory transfers of the human strains of S. salivarius nor by mutagenesis of the cultures.

Animals↗
PubMed1979

Chemical composition of Streptococcus mutans cell walls and their susceptibility to Flavobacterium L-11 enzyme.

The susceptibility to a cell wall lytic L-11 enzyme from Flavobacterium sp. and the quantitative and/or qualitative composition of the cell walls of some strains of cariogenic Streptococcus mutans and a non-cariogenic strain of Streptococcus mitis were determined. The purified cell walls of S. mutans strains HS-1 (serotype a), BHT (b), NCTC10449 (c), C67-1 (c), C67-25 (c), OMZ 176 (d), MT703 (e), MT557 (f), OMZ65 (g), and AHT (g), and S. mitis CHT contained glutamic acid, alanine, and lysine as well as muramic acid and glucosamine as a peptidoglycan component. Besides these amino acids, significant amounts of threonine were detected in strains HS-1, OMZ65, and AHT cell walls, and considerable amounts of aspartic acid and/or threonine as well as several other amino acids in OMZ176, OMZ65, and CHT cell walls. Rhamnose was a common special component of the cell walls of S. mutans strains BHT, NCTC10449, MT703, B2 (e), MT557, and AHT, and S. mitis CHT. An additional sugar component, glucose, was detected in the cell walls of all of these strains except BHT, and galactose was found in BHT, AHT, and CHT cell walls. Galactosamine was present in S. mitis CHT cell walls. Varying amounts of phosphorus were detected in the cell walls of all the strains examined. The cell walls of all these streptococcal strains except MT703, 6715, and AHT were susceptible to the lytic action of the L-11 enzyme to various extents. No consistent relationship was observed between the amino acid and sugar composition of these cell walls and their susceptibility to the L-11 enzyme. The chemical composition of these cell walls is discussed in terms of the serological classification of S. mutans.

Amino Acids↗
PubMed1978

Dental caries induction in experimental animals by clinical strains of Streptococcus mutans isolated from Japanese children.

Oral implantation and the cariogenic activity of clinical strains of Streptococcus mutans which had been isolated from Japanese children and labeled with streptomycin-resistance were examined in specific pathogen-free Sprague-Dawley rats. All the seven strains tested were easily implanted and persisted during the experimental period. Extensive carious lesions were produced in rats inoculated with clinical strains of S. mutans belonging to serotypes c, d, e, and f, and maintained on caries-inducing diet no. 2000. Noninfected rats did not develop dental caries when fed diet no. 2000. Type d S. mutans preferentially induced smooth surface caries in the rats. Strains of other serotypes primarily developed caries of pit and fissure origin. Caries also developed in rats inoculated with reference S. mutans strains BHTR and FAIR (type b) that had been maintained in the laboratories for many years. However, the cariogenicity of the laboratory strains was found to have decreased markedly. All three S. sanguis strains could be implanted, but only one strain induced definite fissure caries. Two S. salivarius strains could not be implanted well in the rats and therefore they were not cariogenic. Four different species of lactobacilli also failed to induce dental caries in rats subjected to similar caries test regimen on diet no. 200. S. mutans strain MT6R (type c) also induce caries in golden hamsters and ICR mice, but of variable degrees.

Animals↗
PubMed1976

Epidemiological survey of Streptococcus mutans among Japanese children. Identification and serological typing of the isolated strains.

An epidemiological investigation was carried out to identify and determine the serotypes of Streptococcus mutans from carious lesions of young Japanese children. For this purpose, a direct fluorescent antibody technique was mainly used. Fluorescein isothiocyanate-conjugated antibodies were prepared for the five known serotypes of S. mutans. Cross reactions and nonspecific reactions were eliminated by adsorption, counterstaining, or DEAE-cellulosecolumn chromatography. Agar-gel immunodiffusion was used to distinguish between serotypes a and d. The epidemiological survey suggested that serotype c strains were most prevalent in dental plaques of Japanese children. The d and e serotypes were rare and serotypes a and b were not detected. It was also noted that more than one serotype of S. mutans could be found in the same locus of a carious lesion and that there might be no relationship between the degree of caries and the causative serotype(s) of S. mutans.

Antibodies, Bacterial↗
PubMed1976

Inhibition of rat dental caries by dextranase from a strain of Spicaria violacea.

Dextranase AD17 obtained from a culture liquor of a strain of Spicaria violacea was assessed for its ability to inhibit the development of dental caries in conventional Sprague-Dawley rats which had been infected with one of the Streptococcus mutans strains. MT6R (serotype c), OMZ 176R (d), or MT-703R (e). These experiments showed that caries was significantly inhibited when rats were given cariogenic diets No. 2000 and drinking water containing AD17 at a concentration of 10 units/g, as compared to control rats not given dextranase. The inhibitory effects of AD17 were more prominent in smooth surface caries than in total caries. AD17 had a tendency to retard both the establishment of inoculated S. mutans and plaque deposition on tooth surfaces. However, S. mutans could be implanted in the rat oral cavity after repeated inoculation of the bacteria, even in the presence of AD17. These results suggest that the anticaries activity of AD17 is due to not only inhibition of adherence of S. mutans cells on tooth surfaces but also to physiochemical changes of dental plaque formed under the enzymatic action of AD17. Preliminary histophatological examination showed that AD17 had no significant toxicity in rats.

Animals↗
PubMedDate not supplied

Inhibitory effects of oolong tea extract on caries-inducing properties of mutans streptococci.

The inhibitory effects of oolong tea extract (OTE) on the caries-inducing properties of mutans streptococci were examined in vitro. OTE reduced the rate of acid production by mutans streptococci accompanied with the retardation of growth rate of mutans streptococci, while the action by chromatographically isolated oolong tea polyphenol (OTF6) was weak. On the other hand, both oolong tea products decreased cell surface hydrophobicity of almost all the oral streptococci examined in the present study, and also induced cellular aggregation of Streptococcus mutans, Streptococcus oralis, Streptococcus sanguis or Streptococcus gordonii. In these reactions, OTF6 showed a more pronounced activity than OTE. Furthermore, the oolong tea products inhibited the adherence of mutans streptococci to saliva-coated hydroxyapatite. These results suggest that OTF6 may inhibit bacterial adherence to the tooth surfaces by reducing the hydrophobicity of mutans streptococci, and OTE may inhibit caries-inducing activity of mutans streptococci by reducing the rate of acid production.

Bacterial Adhesion↗
PubMedDate not supplied

Antibacterial activity of polyphenol components in oolong tea extract against Streptococcus mutans.

The purpose of the present study was to determine the antibacterial activity of oolong tea extract on oral streptococci, including Streptococcus mutans and Streptococcus sobrinus, and to identify the response to its components. Antibacterial activity was found when the extract was added to S. mutans cells in chemically defined medium but not in complex broth media. Further, pretreatment with bovine serum albumin reduced the antibacterial activity. The extract showed antibacterial activity against all of the oral streptococci examined, with the highest activity against S. mutans MT8148R. This activity was found to originate from a monomeric polyphenol-rich fraction, and it was stronger than that of pure polyphenols. Moreover, some combinations of monomeric polyphenols showed the highest level of antibacterial activity. These results suggest that the antibacterial activity of oolong tea extract is caused by a synergistic effect of monomeric polyphenols, which can easily bind to proteins.

Animals↗
PubMedDate not supplied

Role of glucose side chains with serotype-specific polysaccharide in the cariogenicity of Streptococcus mutans.

Previously, we isolated and characterized a new Streptococcus mutans strain (serotype k) from human blood and oral cavity samples, and found that the serological properties of serotype k strains were similar to those of a gluA-inactivated mutant strain of MT8148 (MT8148GD). MT8148GD showed significantly lower sucrose-dependent adhesion to glass surfaces, sucrose-independent adhesion to saliva-coated hydroxyapatite, dextran-binding activity, and cell-associated glucosyltransferase (GTF) activity than the parent strain. Further, Western blot analysis revealed reduced GTFB and GTFC expression in serotype k strains as compared to MT8148, though the caries-inducing activities of MT8148GD and a serotype k oral isolate in rats were similar to that of MT8148. We conclude that a glucose side-chain defect in the serotype-specific polysaccharide of S. mutans may be associated with its cariogenicity, though to a lesser extent than its other major surface proteins.

Animals↗
PubMedDate not supplied

Cariogenicity of the probiotic bacterium Lactobacillus salivarius in rats.

Probiotic bacteria such as lactobacilli and bifidobacteria are considered to be non-pathogenic and non-toxigenic on the basis of long years of safe usage. However, some species of lactobacilli are thought to be associated with the development of dental caries. The purpose of the present study was to examine the cariogenicity of the probiotic bacterium Lactobacillus salivarius in rats. Rats were divided into six groups, and infected with L. salivarius LS1952R and/or Streptococcus mutans MT8148R. L. salivarius LS1952R became established in the oral cavity of rats and induced significant level of dental caries even when infected for only 5 days from 18 to 22 days of age. In addition, the caries scores of rats superinfected with both Streptococcus mutans MT8148R and L. salivarius LS1952R from 18 days of age were significantly higher than those infected with either L. salivarius LS1952R or S. mutans MT8148R alone. Since strain LS1952R can adhere to saliva-coated hydroxyapatites, it is concluded that L. salivarius strain LS1952R possesses an inherent cariogenic activity following adherence to the tooth surface.

Analysis of Variance↗
PubMedDate not supplied

Simultaneous presence of a congenitally missing premolar and supernumerary incisor in the same jaw: report of case.

Supernumerary teeth and hypodontia can be regarded as opposite developmental phenomena. An eight-year-old girl presented a concomitant occurrence of a supernumerary tooth and two congenitally missing teeth. The supernumerary tooth was found in the left maxillary incisor region, while the left second premolar in the maxilla and the left lateral incisor in the mandible were congenitally missing. The supernumerary tooth showed a similar color and morphology to those of the maxilla lateral incisor, and the lateral incisor on the mesial side was diagnosed as a supernumerary tooth from dental age, eruption time, and mesiodistal crown dimension. The supernumerary incisor was guided labially to cure an anterior cross-bite, and the lateral incisor, canine, and first premolar were guided distally to compensate for the space left by the congenitally missing left second premolar.

Age Determination by Teeth↗