title: The intracellular accumulation of phagocytic and epithelial cells and the inhibitory effect on Chlamydophila (Chlamydia) pneumoniae of telithromycin and comparator antimicrobials.
abstract: The intracellular accumulation of telithromycin was measured and compared with ciprofloxacin, clarithromycin, minocycline and erythromycin. The activities of telithromycin, clarithromycin and minocycline against Chlamydophila (Chlamydia) pneumoniae were compared in an intracellular killing assay. Maximal telithromycin accumulation (mean intracellular/extracellular concentration ratio) ranged from 6.7 (A549 lung epithelial cells) to 11.8 (THP-1 monocytic cells). This ratio was similar to that of clarithromycin, but less than for minocycline. Minimum inhibitory and minimum lethal telithromycin concentrations against six clinical strains of C. pneumoniae were <0.015-0.03 mg/L and 0.03-0.06 mg/L, respectively, which were lower than those found for minocycline. These results show that telithromycin accumulates rapidly into epithelial cells, similar to previously reported results for phagocytic cells. Intracellular accumulation of telithromycin was lower than that observed for minocycline, but telithromycin demonstrated substantially more potent antichlamydial activity.
authors.affiliation: First Department of Virology, National Institute of Infectious Diseases, Tokyo, Japan. benyama@saitama-med.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Yamazaki
authors.forename: H
authors.initials: H
authors.lastname: Takemura
authors.forename: M
authors.initials: M
authors.lastname: Inoue
authors.forename: M
authors.initials: M
authors.lastname: Ogawa
authors.forename: S
authors.initials: S
authors.lastname: Ando
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology*; D002460:Cell Line; D016993:Chlamydophila pneumoniae / Q000187:drug effects*; D002939:Ciprofloxacin / Q000378:metabolism / Q000494:pharmacology; D017291:Clarithromycin / Q000378:metabolism / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004847:Epithelial Cells / Q000187:drug effects* / Q000382:microbiology; D004917:Erythromycin / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D048628:Ketolides / Q000378:metabolism / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D008911:Minocycline / Q000378:metabolism / Q000494:pharmacology; D010586:Phagocytes / Q000187:drug effects* / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D048628:Ketolides; D002939:Ciprofloxacin; D004917:Erythromycin; D008911:Minocycline; D017291:Clarithromycin; C106791:telithromycin