Glycogen Synthetic Abilities of Actinomyces viscosus and Actinomyces naeslundii Freshly Isolated from Dental Plaque over Root Surface Caries Lesions and Non-carious Sites

Komiyamai, K.; Khandelwal, Ramji L.; Duncan, Dennis

doi:10.1177/00220345860650060701

Cited by 8 publications

(3 citation statements)

References 18 publications

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“…In support of this hypothesis, A. viscosus M100 but not S. sobrinus 6715 was reported to initiate root caries in a rat model of root caries (Firestone et al, 1989). It has been suggested that in root caries, in addition to species-dependent factors, there may be differences in strain-dependent virulence factors which may be a more sensitive indicator of pathogenicity (cariogenicity) than the species to which the strain belongs (Komiyama et al, 1986(Komiyama et al, , 1988Bowden, 1990; van Houte et al, 1990).…”

Section: Discussionmentioning

confidence: 97%

In vitro Demineralization by Strains of Actinomyces viscosus and Streptococcus sobrinus of Sound and Demineralized Root Surfaces

et al. 1993

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Root sections were inoculated with one of two strains of Actinomyces viscosus or a strain of Streptococcus sobrinus and then incubated for 9 days in Trypticase soy broth (TSB) containing 0.25% glucose or TSB supplemented with 0.25% sucrose (TSB+S). Lesion progression was measured from microradiographs. One section from each group was examined with a transmission electron microscope. Lesion progression was associated with a fall in the pH of the medium. However, lesion progression was not correlated with the mean 48-hour pH of the medium. In both TSB and TSB + S, lesion progression with A. viscosus was significantly greater than in the S. sobrinus group. However, the mean 48-hour pH value in TSB + S was lower than that in the S. sobrinus group. Plaque formation in TSB was, subjectively, least in the S. sobrinus group. Examination of transmission electron micrographs revealed bacteria penetrating the surfaces of the sections and extending into the lesion in the A. viscosus groups but not in the S. sobrinus group. This in vitro bacterial plaque model of root caries may be suitable for investigations of the bacterial etiology of root-surface caries and the virulence factors associated with pathogenicity.

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Section: Discussionmentioning

confidence: 97%

In vitro Demineralization by Strains of Actinomyces viscosus and Streptococcus sobrinus of Sound and Demineralized Root Surfaces

et al. 1993

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“…Because they have a moderate to low pH-lowering potential, Actinomyces species are not considered highly cariogenic (14). However, recent studies have shown that A. viscosus and A. naeslundii originating from root caries lesions are able to synthesize significant amounts of glycogen at low pHs, i.e., between 5 and 6, especially from glucose (30,31). The subsequent slow degradation of these polymers (31) may lead to extended periods of acid production, which may increase the cariogenic potential of plaque dominated by these species.…”

Section: Discussionmentioning

confidence: 99%

Microflora associated with experimental root surface caries in humans

Nyvad

Kilian

1990

Infect Immun

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This study describes the microflora from actively progressing root surface caries lesions, in which mineral loss had been determined by quantitative microradiography. The caries lesions were produced experimentally in root surface specimens from human molars inserted in lower partial dentures carried for 3 months by six elderly individuals. A total of 780 bacterial isolates were identified from 13 plaque samples, collected with a punch technique, and six dentin samples. The composition of the microflora showed distinct individual differences. The microflora from plaque samples associated with the highest mineral loss was dominated by either Actinomyces viscosus or a combination of mutans streptococci (serotypes c, d, and f) and Lactobacillus species (L. casei and L. brevis). Plaque from root surfaces with less pronounced mineral loss harbored a more complex microflora comprising gram-positive rods, mutans streptococci, Streptococcus mitis biovar 1, Veillonella spp., gram-negative rods, and low numbers of lactobacilli. In the latter samples, individual variations in the proportions of mutans streptococci (serotypes c, d, and g), Actinomyces species (A. viscosus and A. naeslundiO), and Veillonella parvula biotypes were observed. These findings suggest that certain species or combinations of species are more cariogenic than others and that dominance of single acidogenic species in particular is conducive to high caries activity.

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“…A. viscosus strain 262 and A. naeslundii strain 151 were originally isolated from the plaques over root surface caries lesions, whereas A. viscosus strain 251 and A. naeslundii strain 226 were ori ginally isolated from the plaques over intact root surfaces [Komiyama et al, 1986]. These strains have been kept in vials containing serum-coated glass beads at -70°C [Ellen et al, 1983], and have never been subcultured.…”

Section: Organisms and Cultural Conditionsmentioning

confidence: 99%

Glycogen Synthetic and Degradative Activities by Actinomyces viscosus and Actinomyces naeslundii of Root Surface Caries and Noncaries Sites

Komiyama¹,

Khandelwal

Heinrich³

1988

Caries Res

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The relative glycogen synthetic and degradative activities of Actinomyces viscosus and Actinomyces naeslundii, freshly isolated from root surface caries and noncaries sites, were compared. The glycogen synthetic activity was measured by incubating glucose-(or sucrose-)grown resting cells with 100 mM glucose (or sucrose) and U-[¹⁴C]-glucose (or U-[¹⁴C]-sucrose) on a pH-stat maintained at 5.0, 6.0, and 7.0 for 1 h under anaerobic conditions. For the glycogen degradation assays, after the 1-hour incubation period, the cells were reincubated under similar conditions, but in the absence of external carbon sources. Carbohydrate utilization and total acid formation were also monitored. Both the glucose- and sucrose-grown cells of A. viscosus and A. naeslundii strains originating from root surface caries lesions synthesized approximately twice as much glycogen as the strains of noncaries origin. Although there were significant differences in the rates of glycogen synthesis, the rates of glycogen degradation were essentially the same for the Actinomyces strains from both caries and noncaries sites. However, the time required for glycogen degradation by the strains from caries sites was much longer. This study suggests that the abilities of A. viscosus and A. naeslundii originating from root surface caries lesions to synthesize large amounts of glycogen and to degrade this stored polymer slowly under conditions of starvation, particularly in an acidic environment, may be one of the factors contributing to the cariogenic potential of these organisms in root surface caries.

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Glycogen Synthetic Abilities of Actinomyces viscosus and Actinomyces naeslundii Freshly Isolated from Dental Plaque over Root Surface Caries Lesions and Non-carious Sites

Cited by 8 publications

References 18 publications

In vitro Demineralization by Strains of Actinomyces viscosus and Streptococcus sobrinus of Sound and Demineralized Root Surfaces

In vitro Demineralization by Strains of Actinomyces viscosus and Streptococcus sobrinus of Sound and Demineralized Root Surfaces

Microflora associated with experimental root surface caries in humans

Glycogen Synthetic and Degradative Activities by Actinomyces viscosus and Actinomyces naeslundii of Root Surface Caries and Noncaries Sites

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