Update on minocycline in vitro activity against odontogenic bacteria

Abstract

Periodontitis, which is a chronic inflammation caused by biofilm from numerous gram-negative and -positive oral bacterial species between gingiva and tooth, is known to have a poor prognosis.Susceptibility of standard strains (19 strains) and clinical isolates (90 strains) of aerobic and anaerobic oral bacteria, including a recently recovered as novel pathogens for periodontitis called Filifactor alocis, was tested to minocycline (MINO) by using the agar dilution method according to the Clinical and Laboratory Standards Institute.MINO is a well-used therapeutic antibiotic for periodontits. In this study, minimum inhibitory concentrations (MICs) of MINO against Aggregatibacter actinomycetemcomitans (n = 1), Porphyromonas gingivalis (n = 5), Prevotella intermedia (n = 1), Tannerella forsythia (n = 1) and F. alocis (n = 1), were 0.12, ≤0.016–0.03, ≤0.016, 0.03, and 2 μg/mL, respectively. MICs range of MINO against clinical isolates (10 isolates each) Streptococcus intermedius, P. gingivalis, P. intermedia, Fusobacterum nucleatum, Parvimonas micra were 0.06–16, ≤0.016–0.03, ≤0.016–1, ≤0.016–0.12, and ≤0.016–0.25 μg/mL, respectively.These results showed that MINO has superior in vitro activities against to known and recent recovered oral bacteria. Moreover, low prevalence in non-susceptible bacteria was observed to MINO.