Microflora associated with experimental root surface caries in humans

Abstract

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.

Involvement of neutrophil recruitment and protease-activated receptor 2 activation in the induction of IL-18 in mice

“…Priming of mice with the Actinomyces species is also effective in inducting serum IL-18 after challenge with LPS, although the magnitude of the priming effect is lower than that with P. acnes (data not shown). Actinomyces species are dominant, commensal oral bacteria, which colonize the dental and mucosal surfaces of various animal hosts and have been implicated in caries [43], periodontitis [44], and root canal infection [45] as well as actinomycosis and septic infection [46]. This indicates that infection with oral bacteria in periodontal tissues augments the sensitivity to LPS of periodontopathic Gram-negative bacteria and serine proteases from infiltrating neutrophils, resulting in induction of IL-18 from oral epithelial cells through the PAR2 pathway, as described previously [15].…”

The in vitro study of ursolic acid and oleanolic acid inhibiting cariogenic microorganisms as well as biofilm

“…and Actinomyces spp. play key roles in cariogenesis (Nyvad and Kilian, 1990;Burne, 1998). Streptococcus mutans is considered the main cariogenic agent, and there is a great deal of literature on its virulence factors (Banas, 2004;Bowen and Koo, 2011).…”

Clonal diversity of the Streptococcus mitis biovar 1 population in the human oral cavity and pharynx

“…It is usually found in high numbers on the buccal and pharyngeal mucosa and participates in the initial colonization of tooth surfaces (20). Recent investigations have suggested that 5. mitis biovar 1 may be implicated in nursing bottle caries and caries on root surfaces (5,21). IgAl protease activity and amylase binding are variable properties of 5".…”

“…Lanes A, S. Molecular weight marker (23 kb, 9.4 kb, 6.6 kb, 4.4 kb, 2.3 kb, 2.0 kb). Lanes B-G. Isolates from the infant representing genotypes 2,[20][21][22][23][24]; Lanes H-L. Isolates from the pharynx of the mother representing genotypes 6-9; Lanes M-R. Isolates from the buccal mucosa of the mother representing genotypes 1-6.…”