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Proportional distribution and relative adherence of Streptococcus miteor (mitis) on various surfaces in the human
Abstract:
A group of streptococci possessing the characteristics of Streptococcus miteor (S. mitis) was found to predominate on nonkeratinized human oral mucosa. These organisms averaged from 76 to 89% of the total flora cultivable on anaerobically incubated blood agar plates from cheek, lip, and ventral tongue surfaces. They averaged 34, 40, and 18% of the streptococci in dental plaque, in saliva, and on the tongue dorsum, respectively. Their ability to adhere to oral surfaces was studied by introducing mixtures of streptomycin-resistant strains of S. miteor, S. salivarius, and S. mutans into the mouths of volunteers. Samples of oral surfaces taken 1 hr later indicated S. miteor adhered far better than the other streptococci to buccal mucosa and to teeth, but S. salivarius showed a higher affinity to the tongue dorsum. Glucose-grown cells of S. mutans adhered feebly to all oral surfaces studied and were rapidly cleared from the mouth. Cells of S. miteor and S. salivarius present naturally in saliva adhered to cleaned teeth comparable to in vitro cultivated strains. Electron microscopy of cells of S. miteor attached to buccal epithelial cells obtained from germfree rats indicated that the organisms possessed a fibrillar "fuzzy" coat which appeared to mediate their attachment to the epithelial cell membrane. This "fuzzy" coat was removed by treatment with trypsin, and it appears to be similar to that previously observed on cells of S. pyogenes and S. salivarius.
Insights
Streptococcus miteor (S. mitis) dominates nonkeratinized oral mucosa and adheres strongly to buccal surfaces and teeth. This oral bacterium possesses a unique fibrillar coat mediating its attachment to epithelial cells.
Area of Science:
- Microbiology
- Oral Biology
- Bacteriology
Background:
- Streptococci are key components of the human oral microbiome.
- Understanding streptococcal adherence is crucial for oral health research.
- Specific streptococcal species exhibit distinct colonization patterns.
Purpose of the Study:
- To investigate the predominant streptococcal species on human oral mucosa.
- To compare the adherence capabilities of different oral streptococci to various oral surfaces.
- To elucidate the mechanism of Streptococcus miteor adherence.
Main Methods:
- Culturing and quantifying streptococci from human oral surfaces (cheek, lip, tongue, plaque, saliva).
- Assessing adherence of streptomycin-resistant strains (S. miteor, S. salivarius, S. mutans) in vivo.
- Utilizing electron microscopy to examine S. miteor attachment to epithelial cells.
Main Results:
- Streptococcus miteor predominated on nonkeratinized oral mucosa, comprising 76-89% of cultivable flora.
- S. miteor demonstrated superior adherence to buccal mucosa and teeth compared to S. salivarius and S. mutans.
- S. salivarius showed higher affinity for the tongue dorsum; S. mutans adhered poorly.
- A fibrillar 'fuzzy' coat on S. miteor was identified as the likely mediator of epithelial cell attachment.
Conclusions:
- Streptococcus miteor is a dominant inhabitant of human oral mucosa with significant adherence properties.
- The 'fuzzy' coat of S. miteor plays a critical role in its colonization of oral surfaces.
- Differential adherence of streptococci influences their ecological niches within the oral cavity.