Extracellular glucans produced by oral streptococci

Nisizawa, Tosiki; Imai, Shoichi; Akada, H.; Hinoide, Moriyo; Araya, Shimpei

doi:10.1016/0003-9969(76)90131-x

Cited by 35 publications

(21 citation statements)

References 21 publications

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“…show a higher share of a-(l-»-3)-plus a-(l ^-linkages than EPS of the fraction PS/ethan. This result is in full accordance with the generally accepted as sumption that high portions of a-(l-*3)-linkages are responsible for the insolubility of streptococcal glucans [Ceska et al, 1972;Nisizawa et al, 1976]. As a consequence of this difference the fraction PS/ethan.…”

Section: Discussionsupporting

confidence: 78%

Fractionation of Glucans Synthesized by Streptococcus mutans in vitro

Trautner¹,

Felgenhauer²

1979

Caries Res

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Extracellular polysaccharides (EPS) synthesized by Streptococcus mutans in vitro and insoluble in the culture supernatant are shown to be mixtures of water-insoluble and water-soluble EPS. After dissolving in potassium hydroxide and subsequent neutralization only part of the EPS precipitates (insoluble fraction). Another part can be isolated from the neutralized solution by the addition of ethanol (soluble fraction). Some samples show remarkable amounts of carbohydrate material, soluble even in 70% ethanol or material which can pass dialysis membranes. The insoluble fraction shows a higher share of α-(l→3)-linkages and is less susceptible to dextranase than the soluble fraction. It is suggested that the soluble fraction might be surrounded by insoluble polysaccharide or might be linked to cell-associated glucosyl-transferase, thus becoming part of an insoluble complex. Insoluble EPS synthesized by isolated glucosyltransferase of 5. mutans showed no fractionation after alkaline treatment.

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Section: Discussionsupporting

confidence: 78%

Fractionation of Glucans Synthesized by Streptococcus mutans in vitro

Trautner¹,

Felgenhauer²

1979

Caries Res

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“…It is not possible to distinguish 1 -+ 2 from 1 --3 linkages because of the similarity of the retention times of their trimethyl glucitols, 1.83 and 1.82, respectively. Others have reported that this linkage is a minor or absent secondary linkage (1,6,31,37) in S. mutans glucan. Nonetheless, it is possible that the glucans described here contain some 1 --2 as well as minor amounts of 1 --4 linkages.…”

Section: Resultsmentioning

confidence: 90%

In vitro colonization of Streptococcus mutans on enamel

Tinanoff¹,

Tanzer²,

Freedman³

1978

Infect Immun

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An in vitro model consisting of enamel from extracted human molars, suspended from wires in inoculated culture tubes, was used to study the adhesion of bacteria to enamel. Under conditions in which there was no macroscopically visible plaque formation, electron micrographs showed no bacterial deposits on the enamel surface. In samples where Streptococcus mutans attached to enamel, an extracellular, pellicle-like material was'associated with the bacteria adjacent to the enamel. This material appeared to bind to the enamel surface and to mediate bacterial attachment. Membrane-filtered (Millipore Corp.) saliva deposited a thin surface layer on the enamel, but there were no observable alterations of S. mutans attachment to enamel pretreated with saliva. It was noted that Bratthall serotype c and e strains of S. mutans, when grown in glucose-containing medium, attached, although less tenaciously, to enamel and nichrome wires. Chemical and gas chromatographic analyses of cell-associated materials formed by serotype c and e strains cultured in glucose-containing medium revealed low amounts of glucosepositive material and no polymer linkages characteristic of glucan; yet the same strains cultured in sucrose-containing medium had relatively high amounts of glucose-positive material, with polymer linkages characteristic of glucan. Serotype a, b, and d strains could attach only in sucrose-containing media.Bacterial plaque formation on tooth enamel may be dependent on two types of adhesion phenomena. Organisms must sorb to the tooth or to organic films on the enamel surface, and organisms must be able to adhere to each other as the plaque enlarges. The abilities of certain bacteria to become attached to enamel and to proliferate while localized there seem to be the major ecological determinants influencing formation of plaque and pathogenicity (11,41). The events and mechanisms are, however, not completely understood.A large body of evidence strongly implicates Streptococcus mutans as a prime pathogen in dental caries of humans and experimental animals (2,5,7,10,22,24). S. mutans is known to form glucans from sucrose via glucosyl transferase activity, and the synthesis of cell surfaceassociated glucans from sucrose has been thought essential for this species to form bacterial accumulations termed dental plaque (9,11,13,21,25,29,30,35,40,41, 50).Most models for bacterial attachment to tooth surfaces involve growth of bacteria on wires, glass, plastic, or hydroxyapatite powder. Few ultrastructural studies of plaque formation have used intact tooth enamel (46). However, because of the purported structural distinctness of enamel, its characteristic wettability (14), and the possible specificity of bacterial-enamel interac-tions (12), the early attachment of bacteria to tooth enamel in vitro rather than to enamel substitutes may better parallel events in vivo. The recent development of a technique for making thin sections of the enamel-plaque interface (45) has enabled a study of enamel-bacteria interactions. The purpose of this ...

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“…Furthermore, the cell mass yield (including EMM) obtained after centrifugation of the cultures (6000 g, 10 min, 4VC) was far greater with sucrose-supplemented THB cultures than with THB cultures. These cultural traits are characteristic of the sucrose-specific synthesis of insoluble extracellular glucan, containing predominantly alpha 1:6 and alpha 1:3 glucosidic linkages, by this S. mutans strain (Nisizawa et al, 1976). Each cell mass was washed twice with cold buffer (100 mmol/L KC1, 20 mmol/L KHCO3, pH 7.0).…”

Section: Methodsmentioning

confidence: 99%

Increased pH-lowering Ability of Streptococcus mutans Cell Masses Associated with Extracellular Glucan-rich Matrix Material and the Mechanisms Involved

Houte¹,

Russo²,

Prostak

1989

J Dent Res

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Streptococcus mutans strain IB-1600 was cultivated in Todd-Hewitt broth (THB) or THB supplemented with sucrose (S). Cell mass obtained from THB exhibited a high cell density and negligible glucan-rich extracellular matrix material (EMM), whereas cell mass from 2% S-supplemented THB exhibited widely-spaced cells separated by EMM. The pH-lowering potential of the different cell masses was studied in vivo with an intra-oral enamel demineralization test and rinsing with glucose solution, and in vitro with a model which permits vertical penetration of glucose through the cell mass and pH evaluation at different depths within the cell mass. In vivo, the pH profile of EMM-rich cell mass derived from 2% S-supplemented THB was characterized by a lower pH minimum and a slower return of the pH as compared with THB-derived cell mass. In vitro, an increase in cell mass EMM content was associated with a more rapid initiation and an increase in the rate of pH drop in the depth of the cell masses. Evaluation of the acidogenic potential of the cells in cell masses derived from THB and 2% S-supplemented THB with suspensions of dispersed cell mass and added glucose indicated no difference. The buffering capacity of cell mass derived from 2% S-supplemented THB within the pH range of 6.5-4.0 was greatly reduced as compared with that of THB-derived cell mass, due to the relatively low buffering capacity of EMM. The presence of EMM also appeared to enhance the porosity of the cell mass.(ABSTRACT TRUNCATED AT 250 WORDS)

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Extracellular glucans produced by oral streptococci

Cited by 35 publications

References 21 publications

Fractionation of Glucans Synthesized by Streptococcus mutans in vitro

Fractionation of Glucans Synthesized by Streptococcus mutans in vitro

In vitro colonization of Streptococcus mutans on enamel

Increased pH-lowering Ability of Streptococcus mutans Cell Masses Associated with Extracellular Glucan-rich Matrix Material and the Mechanisms Involved

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