The prevalence of beta lactamase-producing anaerobic oral bacteria in South African patients with chronic periodontitis.

INTRODUCTION

Antimicrobial resistance is on the increase in 'medical and dental fields. Beta-lactam antibiotics are the most widely used antimicrobials in dental patients.

OBJECTIVES

This study investigated the prevalence of beta-lactamase-producing anaerobic oral bacteria in patients with chronic periodontitis.

METHODS

Pooled subgingival samples from two sites in 42 patients with chronic periodontitis were cultured anaerobically on blood agar plates containing amoxycillin or/and Augmentin. Colonies that grew on amoxycillin but not Augmentin were identified and tested for beta-lactamase production.

RESULTS

Sixty-nine percent of patients carried beta-lactamase-producing anaerobes, with a mean of one to two strains per patient. Seventy isolates of the beta-lactamase- producing strains formed 4% of the total cultivable anaerobic flora. Prevotella was the most prevalent beta-lactamase-producing species, followed by Capnocytophaga, Veillonella and Bacteroides.

CONCLUSIONS

A high prevalence of beta-lactamase-producing oral anaerobes was detected in this preliminary study. However, the percentage of beta-lactamase producers in the total number of bacteria per patient was low. Therefore, beta-lactam antibiotics still remain the drug of choice in infections with odontogenic origin.