title: In vitro susceptibilities of Rickettsia rickettsii and Rickettsia conorii to roxithromycin and pristinamycin.
abstract: In vitro susceptibilities of Rickettsia rickettsii and Rickettsia conorii to roxithromycin, pristinamycin, and the pristinamycin compounds, P1 and P2, were determined by a dye uptake assay and a plaque assay. The MICs were 1 microgram/ml for roxithromycin, 2 micrograms/ml for pristinamycin, greater than 256 micrograms/ml for P1, and 2 micrograms/ml for P2. Compounds P1 and P2 did not share synergetic activity. The toxicity of each compound was determined by a dye uptake assay. Toxic concentrations were 128 micrograms/ml for roxithromycin, 32 micrograms/ml for pristinamycin, greater than 256 micrograms/ml for P1, and 32 micrograms/ml for P2. Roxithromycin and pristinamycin could be useful in the treatment of Rocky Mountain spotted fever and Mediterranean spotted fever.
authors.affiliation: Centre National de Référence des Rickettsioses, Centre Hospitalier Universitaire Timone, Marseille, France.
authors.forename: M
authors.initials: M
authors.lastname: Drancourt
authors.forename: D
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000633:toxicity; D008826:Microbial Sensitivity Tests; D010456:Peptides, Cyclic / Q000494:pharmacology / Q000633:toxicity; D012281:Rickettsia / Q000187:drug effects*; D012284:Rickettsia rickettsii / Q000187:drug effects*; D015575:Roxithromycin / Q000494:pharmacology* / Q000633:toxicity; D014709:Vero Cells / Q000187:drug effects; D014769:Virginiamycin
chemical_list: D000900:Anti-Bacterial Agents; D010456:Peptides, Cyclic; D014769:Virginiamycin; D015575:Roxithromycin