Peptostreptococcus micros smooth and rough genotypes in periodontitis and gingivitis

Area of Science:

• Oral microbiology
• Periodontal disease research
• Bacterial genetics

Background:

• Peptostreptococcus micros exists in two genotypes: smooth (Sm) and rough (Rg).
• Previous research lacked systematic studies on the prevalence of these genotypes in periodontitis and gingivitis patients.
• The study aimed to clarify the roles of Sm and Rg genotypes in periodontal health and disease.

Purpose of the Study:

• Investigate the prevalence and proportion of Sm and Rg genotypes of P. micros in periodontitis and gingivitis.
• Examine the correlation between smoking habits and the prevalence of these two P. micros genotypes.
• Assess the systemic antibody response against both P. micros genotypes in relation to periodontal status and smoking.

Main Methods:

• Clinical examination and microbiological sampling of 104 periodontitis patients and 41 gingivitis subjects.
• Anaerobic culture of pocket samples to determine P. micros genotype prevalence and proportion.
• Enzyme-linked immunosorbent assay (ELISA) and immunoblotting to measure serum antibody titers and specificity against P. micros genotypes.

Main Results:

• The Sm genotype was more prevalent in periodontitis (94%) than gingivitis (59%) patients.
• The Rg genotype showed higher prevalence in periodontitis patients who smoke (48%) compared to non-smokers (19%).
• No significant differences in antibody titers or specificity were found based on periodontal condition or smoking status.

Conclusions:

• Both Sm and Rg genotypes of P. micros are part of the normal oral microbiota.
• The Sm genotype's increased prevalence in periodontitis suggests a role in disease development.
• The Rg genotype's association with smoking in periodontitis patients indicates its potential as an opportunistic pathogen.