The production of dental plaque and caries by the bacterium Streptococcus salivarius in gnotobiotic WAG/RIJ rats

Drucker, D.B.; Shakespeare, Ann P.; Green, R.M.

doi:10.1016/0003-9969(84)90024-4

Cited by 33 publications

(23 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is a major organism in Artificial Mouth plaques cultured from saliva with a highly acidogenic nutrient schedule, including four hourly sucrose rinses (Sissons et al, 1988a,b). It can form highly cariogenic plaques in gnotobiotic rats (Drucker et al, 1984). Possibly, S. salivarius is localized, for example, in surface layers where salivary access is greatest.…”

Section: Discussionmentioning

confidence: 99%

pH Regulation of Urease Levels in Streptococcus salivarius

et al. 1990

View full text Add to dashboard Cite

Potential mechanisms for regulation of urease levels in Streptococcus salivarius were examined, including: induction by urea, nitrogen or carbon source repression, and effects of pH and CO2 (because CO2 enrichment enhanced urease detection on urea agar plates). Regulation by either pH or CO2 was confirmed by comparison of the urease accumulation pattern during anaerobic growth under CO2 with that under N2. Under CO2, there was an initial buffering plateau at pH 6.2 and a rate of Streptococcus salivarius urease accumulation three-fold that under N2, with a pH 7.6 plateau. With both gas phases there was also an increase in the rate of urease appearance coincident with the decrease in medium pH following the pH plateau. The effects of pH, CO2, and HCO3- on urease levels and on growth were separately assessed by culture in media containing 0, 25, 100 mmol/L KHCO3 buffered at different pH levels. There was an inverse relationship between the logarithm of the urease level after 24-hour growth and the pH during growth-the urease specific activity was 100-fold higher at pH 5.5, compared with pH 7.0 and above. HCO3-/CO2 (100 mmol/L) had little effect on urease levels, but was essential for growth at pH 5.5. There was no significant urease induction by urea, or repression by ammonia or glucose. There was also evidence of pH regulation of urease levels in some staphylococci, Klebsiella pneumonia, and Corynebacterium renale, but not in Actinomyces naeslundii and several other species. We conclude that the external pH is a major factor regulating urease levels in S. salivarius and possibly some other species-a mechanism equivalent to urease repression by OH-.

show abstract

Section: Discussionmentioning

confidence: 99%

pH Regulation of Urease Levels in Streptococcus salivarius

et al. 1990

View full text Add to dashboard Cite

show abstract

“…Both species are abundant in cariogenic dental plaque [Okada et al, 2005;Martínez-Martínez et al, 2011]. Cluster analysis of subjects with active caries showed that several had high levels of S. vestibularis or S. salivarius [Gross et al, 2012], and S. salivarius has been shown to be strongly cariogenic in animal studies, although less so than S. mutans [Drucker et al, 1984;Willcox et al, 1991] . Oral streptococci, including S. sanguinis , S. gordonii , and S. mitis, are the dominant 'pioneer' species in dental biofilm formation [Ritz, 1967], but they are associated with healthy tooth surfaces [Ge et al, 2008;Gross et al, 2012].…”

Section: Discussionmentioning

confidence: 99%

Activity of Synthetic Antimicrobial Peptide GH12 against Oral Streptococci

Fan²,

Lv³

et al. 2016

Caries Res

View full text Add to dashboard Cite

Controlling the growth of cariogenic microorganisms such as oral streptococci is an adjunct therapy for caries-active individuals to prevent and treat caries. Here we investigated the antimicrobial activity of the synthetic amphipathic α- helical antimicrobial peptide GH12 (GLLWHLLHHLLH-NH₂) against oral streptococci in vitro. Circular dichroism studies showed that GH12 takes on an α-helical conformation in the presence of membrane-mimicking solvents, and reversed-phase high-performance liquid chromatography studies showed that GH12 remains stable in saliva. The peptide showed bactericidal activity against oral streptococci, with minimum inhibitory concentrations ranging from 6.7 to 32.0 μg/ml. GH12 concentrations 4-fold higher than the minimum bactericidal concentration completely killed oral streptococci within 20 min. Treating oral streptococci with GH12 caused noticeable changes in bacterial viability and morphology based on confocal laser scanning microscopy and scanning electron microscopy. Effects of GH12 on biofilm formation and on viability of mature biofilm were quantified by crystal violet staining and the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. GH12 effectively inhibited biofilm formation and metabolic activity in biofilms of oral streptococci, especially S. mutans, S. sobrinus and S. salivarius. These results suggest that GH12 shows rapid and strong antimicrobial activity against oral streptococci in vitro, opening the door to preclinical and clinical studies to explore its potential for caries prevention and treatment.

show abstract

“…salivarius may be cariogenic (Drucker, Shakespeare and Green, 1984), so general conceptions of species being either cariogenic or non-cariogenic may not be entirely tenable.…”

Section: Role Of Polysaccharide Metabolism In Dental Cariesmentioning

confidence: 99%

Dental caries

Jenkinson¹

1999

Medical Importance of the Normal Microflora

View full text Add to dashboard Cite

The production of dental plaque and caries by the bacterium Streptococcus salivarius in gnotobiotic WAG/RIJ rats

Cited by 33 publications

References 21 publications

pH Regulation of Urease Levels in Streptococcus salivarius

pH Regulation of Urease Levels in Streptococcus salivarius

Activity of Synthetic Antimicrobial Peptide GH12 against Oral Streptococci

Dental caries

Contact Info

Product

Resources

About