title: Changes in antimicrobial susceptibility profile and prevalence of quinolone low-sensitive strains in subgingival plaque from acute periodontal lesions after systemic administration of sitafloxacin.
abstract: This study aimed to assess changes in antimicrobial susceptibilities of subgingival bacteria in acute periodontal lesions following systemic administration of a new-generation fluoroquinolone, sitafloxacin and to monitor the occurrence and fate of quinolone low-sensitive strains. Patients with acute phase of chronic periodontitis were subjected to microbiological assessment of their subgingival plaque samples at baseline (A1). Sitafloxacin was then administered systemically (100 mg/day for 5 days). The microbiological examinations were repeated one week after administration (A2). Susceptibilities of clinical isolates from acute sites to various antimicrobials were determined using broth and agar dilution methods. At A2, subgingival bacteria with low sensitivity to levofloxacin were identified in four patients, and they were subjected to a follow-up microbiological examination at on the average 12 months after sitafloxacin administration (A3). The patients received initial and supportive periodontal therapy during the period A2 to A3. From the examined subgingival sites, 8 and 19 clinical isolates were obtained at A2 and A3, respectively. Some Streptococcus strains isolated at A2 were found to be resistant to levofloxacin (MIC 16-64 μg/ml), azithromycin (MIC 2->128 μg/ml) or clarithromycin (MIC 1->32 μg/ml). At A3, isolated streptococci were highly susceptible to levofloxacin (MIC 0.5-2 μg/ml), while those resistant to azithromycin or clarithromycin were still isolated. It is suggested that the presence of the quinolone low-sensitive strains in initially acute lesions after sitafloxacin administration was transient, and they do not persist in the subgingival milieu during the periodontal therapy.
authors.affiliation: Department of Periodontology, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Tomita
authors.affiliation: Department of Dentistry and Oral Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Kasai
authors.affiliation: Department of Periodontology, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Imamura
authors.affiliation: Department of Dentistry and Oral Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Ihara
authors.affiliation: Department of Periodontology, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.
authors.forename: Daichi
authors.initials: D
authors.lastname: Kita
authors.affiliation: Department of Periodontology, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.
authors.forename: Koki
authors.initials: K
authors.lastname: Ota
authors.affiliation: Department of Periodontology, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan.
authors.forename: Jin
authors.initials: J
authors.lastname: Sekino
authors.affiliation: Department of Dentistry and Oral Surgery, School of Medicine, Keio University, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan.
authors.forename: Taneaki
authors.initials: T
authors.lastname: Nakagawa
authors.affiliation: Department of Periodontology, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan; Oral Health Science Center, Tokyo Dental College, 2-9-18 Misaki-cho, Chiyoda-ku, Tokyo 101-0061, Japan. Electronic address: atsaito@tdc.ac.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Saito
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001419:Bacteria / Q000187:drug effects* / Q000302:isolation & purification; D003773:Dental Plaque / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D024841:Fluoroquinolones / Q000627:therapeutic use*; D006801:Humans; D008137:Longitudinal Studies; D008826:Microbial Sensitivity Tests; D010518:Periodontitis / Q000188:drug therapy* / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; C076246:sitafloxacin
keywords: Antibiotics; Drug resistance; Drug therapy; Microbial sensitivity tests; Periodontal pocket; Periodontitis