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Macrolides and changes in the oral flora

A M Sefton1

  • 1Department of Medical Microbiology, St. Bartholomew's and the Royal London School of Medicine and Dentistry, UK.

International Journal of Antimicrobial Agents
|April 16, 1999
PubMed

Insights

Macrolide antibiotics like azithromycin can increase resistant oral streptococci but reduce periodontal pathogens, leading to a healthier oral environment. This transient increase in resistant bacteria caused no clinical issues in studies.

Area of Science:

  • Microbiology
  • Periodontology
  • Pharmacology

Background:

  • Macrolides are used in dentistry and may treat periodontal disease.
  • Antibiotic use, including macrolides, is linked to increased antibiotic-resistant oral streptococci.
  • Macrolide-resistant streptococci are present in normal oral flora before treatment.

Purpose of the Study:

  • To investigate the effect of macrolide antibiotics on oral flora composition.
  • To confirm the increase in antibiotic-resistant oral streptococci after macrolide administration.
  • To evaluate the impact of macrolides on periodontal pathogens and overall oral health.

Main Methods:

  • Administration of macrolide antibiotics (erythromycin, josamycin, azithromycin) to subjects.
  • Baseline and post-treatment analysis of oral flora, including streptococci and periodontal pathogens.
  • Monitoring for clinical problems associated with changes in oral flora.

Main Results:

  • Macrolide treatment confirmed an increase in macrolide-resistant oral streptococci.
  • Azithromycin treatment led to a decrease in periodontal pathogens like anaerobes and spirochaetes.
  • Oral streptococci counts increased post-azithromycin treatment, indicating a shift towards a healthier oral environment.
  • No clinical issues were observed despite the transient rise in resistant streptococci.

Conclusions:

  • Macrolide antibiotics can transiently increase resistant oral streptococci by eliminating sensitive strains.
  • Azithromycin effectively reduces key periodontal pathogens, promoting a healthier oral microbial balance.
  • The observed shift in oral flora composition following macrolide use is not associated with adverse clinical outcomes.

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