title: Impact of minocycline ointment for periodontal treatment of oral bacteria.
abstract: Topical tetracyclines, such as minocycline ointment, are frequently used for the treatment of periodontal infection. We investigated the influence of minocycline ointment use on oral bacteria, using supragingival plaque samples from adults who had not taken any antibiotics for 6 months. Initially we investigated the effect of topical minocycline administration on the emergence of tetracycline-resistant oral bacteria in four healthy adults. The isolation frequency of tetracycline-resistant oral bacteria to total viable bacteria increased substantially on day 6 after treatment, although it returned to baseline on day 25. Subsequently we investigated the isolation frequency of tetracycline-resistant oral streptococci (TOS) as a representative oral bacterium, using samples from 41 subjects with periodontal diseases. The percentage of TOS (of the total oral streptococci) increased significantly (from 11.9±15.6% to 34.2±24.0%) after minocycline treatment. Various TOS species were identified; S. mitis, S. salivarius, S. sanguinis, and S. oralis were frequently isolated. PCR and Southern blotting allowed us to identify tetM on the Tn916-like elements as the gene responsible for tetracycline-resistance. These findings suggest that the potential risk of the spread of similar genetic elements through bacteria in the oral cavity should be considered.
authors.affiliation: Department of Bacteriology I, National Institute of Infectious Diseases, Tokyo 162-8640, Japan. ryoma73@nih.go.jp
authors.forename: Ryoma
authors.initials: R
authors.lastname: Nakao
authors.forename: Satoko
authors.initials: S
authors.lastname: Takigawa
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Sugano
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Koshi
authors.forename: Koichi
authors.initials: K
authors.lastname: Ito
authors.forename: Haruo
authors.initials: H
authors.lastname: Watanabe
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Senpuku
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D058491:Bacterial Load; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D005798:Genes, Bacterial; D006801:Humans; D008297:Male; D050296:Microbial Viability / Q000187:drug effects; D008875:Middle Aged; D008911:Minocycline / Q000008:administration & dosage* / Q000494:pharmacology; D009824:Ointments / Q000008:administration & dosage*; D010518:Periodontitis / Q000188:drug therapy* / Q000382:microbiology*; D013753:Tetracycline Resistance
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D009824:Ointments; D008911:Minocycline