Production of Acids in Rat Dental Plaque with or without Streptococcus mutans

Hoeven, J.S. van der; Franken, Herman

doi:10.1159/000260623

Cited by 17 publications

(6 citation statements)

References 8 publications

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“…These observations were consistent with the observed mixed-acid fermentation by streptococci in the dental plaque of gnotobiotic rats [2]. This indicated that, except during food intake by the host [3], the streptococci in dental plaque are under carbon and energy limitation and compete for these substrates [4]. At present it is not known how competition for carbon and energy sources would influence the proportions of these microorganisms in dental plaque, mainly because of the complexity of the natural ecosystem and because the available carbon and energy sources have not been studied in detail.…”

Section: Introductionsupporting

confidence: 89%

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Effect of utilization of substrates on the composition of dental plaque

Hoeven

Jong

Rogers

1985

FEMS Microbiology Letters

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The microbiota in the mouth is subjected to substrate limitations. In this study we have evaluated the role of competition for carbon and energy substrates on the proportions of 2 microbial species in a simplified plaque ecosystem in gnotobiotic rats. Germ‐free rats were inoculated with a combination of Streptococcus sanguis and Streptococcus mutans, or with a combination of Streptococcus milleri and S. mutans. The available carbon and energy sources were varied through the host's diet. 3 Experimental diets were tested: (i) a basal diet low in soluble carbohydrates; (ii) an arginine‐supplemented diet; (iii) a sucrose‐supplemented diet. Arginine is used for growth by S. sanguis and S. milleri, but not by S. mutans. Sucrose is rapidly fermented by all 3 species. The total number of viable organisms on the dentition increased when arginine or sucrose were supplied in the diet. With the arginine‐supplemented diet, S. sanguis and S. milleri increased while S. mutans decreased. With the sucrose‐supplemented diet, S. mutans increased while S. sanguis and S. milleri decreased. These results were explained by assuming that the organism with the highest growth rate on the supplementary substrate competes most favourably. Changes in the environmental pH, due to breakdown of sucrose and arginine, might also have affected the competition between the streptococci. In addition, production of extracellular glucans from sucrose could be a competitive advantage for S. mutans.

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Section: Introductionsupporting

confidence: 89%

“…2 Substrates were selected for this experiment, sucrose and arginine. Both substrates are rapidly fermented in dental plaque [3,7,8] and can easily be supplied via the host's diet and drinking water. Several Streptococcus species can ferment arginine via ornithine to citrulline and carbamylphosphate [9,10].…”

Section: Introductionmentioning

confidence: 99%

Effect of utilization of substrates on the composition of dental plaque

Hoeven

Jong

Rogers

1985

FEMS Microbiology Letters

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“…An important feature is that calculations of the rates of growth of plaque organisms indicate that they grow at rates much slower than can be achieved under normal batch growth conditions (17) but which can be attained in the chemostat. The range of pH values examined, 5.5 to 7.5, is also relevant to oral ecology, and growth with limiting carbohydrate is pertinent because evidence indicates that plaque organisms are generally limited in their growth rate by the availability of carbohydrate (16,56).…”

Section: Discussionmentioning

confidence: 99%

Comparative studies on the effect of growth conditions on adhesion, hydrophobicity, and extracellular protein profile of Streptococcus sanguis G9B

Knox¹,

Hardy²,

Markevics³

et al. 1985

Infect Immun

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Streptococcus sanguis G9B was grown in continu6tis culture at different generation times and pH values in media containing either glucose or fructose and differing in the concentrations of Na+ and K'. The growth pH, carbohydrate, and cation concentration each affected the yield of organisms, their ability to adhere to saliva-coated hydroxyapatite beads, and their hydrophobicity, as measured by adhesion to hexadecane. There was no correlation between adhesion to saliva-coated hydroxyapatite beads and hydrophobicity, the values for hydrophobicity varying between 44 and 83% for organisms that adhered poorly and between 24 and 75% for those that adhered effectively. For organisms grown in batch culture at pH 6.0 or 7.0 there was similarly no correlation between adhesion and hydrophobicity. The growth conditions also had a considerable influence on the productibn of extracellular protein. The total amount was greater at pH 7.5 than at other pH values, and there were also differences in the individual components in response to changes in generation time, pH, carbohydrate source, and catidn concentration. Two protein bands were identified, namely, glucosyltransferase and protein P1 (also called antigen B or I/II). However, there was no correlation between a particular protein component and adhesion.

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“…Chemical analysis. Organic acids in the suspended plaques were analyzed by isotachophoresis as described before (18,19). The isotachophoretic analysis has the advantage that no pretreatment of the samples was required, causing no loss of material from the small samples.…”

Section: Methodsmentioning

confidence: 99%

Effect of fluoride on growth and acid production by Streptococcus mutans in dental plaque

Hoeven¹,

Franken²

1984

Infect Immun

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The aim of this study was to measure the effect of fluoride on the production of organic acids by Streptococcus mutans in dental plaque. The effect was studied in a simplified model of dental plaque with gnotobiotic rats monoinfected with S. mutans Ny341. Adaptation of S. mutans to fluoride was induced by feeding one group of the rats on fluoride-containing diet and drinking water. No difference was found in the accumulation of S. mutans on the teeth between the fluoride-adapted and the control groups. However, there was a significant difference in the amount of lactic acid in metabolically resting plaque between the groups, lactic acid being lower in the fluoride-adapted plaque. At 5 min after a rinse containing 10% sucrose, a high level of lactic acid was found in plaque from animals not exposed to fluoride. Rinses containing 4 or 20 mM fluoride before the sucrose rinse significantly inhibited the lactic acid production in the control group. In the plaque from rats on fluoridated diet and drinking water the sucrose-induced production of lactic acid was not inhibited by a 4 mM fluoride rinse. Moreover, the production of lactic acid in the fluoride-adapted plaque was prolonged. The results indicate that due to fluoride adaptation the inhibition of acid production is unlikely to be important for the caries-preventive action of fluoride.Several mechanisms have been proposed to explain the cariostatic effect of fluoride. Fluoride can be incorporated into hydroxyapatite, yielding a fluorapatite, which is more acid resistant. Fluoride can also promote the remineralization of early carious lesions (3,14). In addition, fluoride may reduce the production of acids by bacteria in dental plaque as it is known to inhibit the degradation of glucose by suspensions of dental plaque and salivary sediments at an acidic pH (12, 15). There is little evidence for an effect of fluoride on plaque development. Few differences have been shown between the microbial composition of the plaque from subjects exposed to fluoride and from those in nonfluoridated areas (5,13,17). This suggested that the majority of the bacteria in dental plaque are either insensitive to fluoride or able to adapt or mutate in its presence. The oral Actinomyces spp. are insensitive to fluoride, whereas Streptococcus spp. can adapt to relatively high concentrations of fluoride (1,9). Hamilton and Bowden (10) found that a freshly isolated strain of Streptococcus mutans developed phenotypical resistance against fluoride during growth in a chemostat.The present experiment was undertaken to measure the effect of fluoride on the acid production of S. mutans in dental plaque. This effect was studied in a simplified model of dental plaque with gnotobiotic rats monoinfected with S. mutans. Adaptation of S. mutans to fluoride was induced by feeding the rats on fluoridated diet and drinking water. MATERIALS AND METHODSMicroorganisms. S. mutans Ny341 (serotype c) was isolated in our laboratory from human dental plaque. The plaque was collected in an area with no fluoride add...

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Production of Acids in Rat Dental Plaque with or without Streptococcus mutans

Cited by 17 publications

References 8 publications

Effect of utilization of substrates on the composition of dental plaque

Effect of utilization of substrates on the composition of dental plaque

Comparative studies on the effect of growth conditions on adhesion, hydrophobicity, and extracellular protein profile of Streptococcus sanguis G9B

Effect of fluoride on growth and acid production by Streptococcus mutans in dental plaque

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