title: Activity of azithromycin, clarithromycin, roxithromycin, dirithromycin, quinupristin/dalfopristin and erythromycin against Legionella species by intracellular susceptibility testing in HL-60 cells.
abstract: We evaluated a human monocyte cell line (HL-60) as a model for testing the intracellular activity of anti-Legionella antibiotics; 1.5 x 10(6) HL-60 cells/well were differentiated into adherent cells and infected with 1.5 x 10(7) cfu of Legionella pneumophila. The most active agents against L. pneumophila as judged by broth dilution MICs were (in order of activity) azithromycin, clarithromycin, roxithromycin, quinupristin/dalfopristin, erythromycin and dirithromycin. The most active inhibitors of L. pneumophila intracellular multiplication were (in order of activity) azithromycin, erythromycin, quinupristin/dalfopristin, roxithromycin, dirithromycin and clarithromycin. All the agents were highly active against Legionella micdadei and Legionella bozemanii when compared with L. pneumophila.
authors.affiliation: Special Pathogens Laboratory, Veterans Affairs Medical Center, and The University of Pittsburgh School of Medicine, PA 15240, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Stout
authors.forename: B
authors.initials: B
authors.lastname: Arnold
authors.forename: V L
authors.initials: VL
authors.lastname: Yu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology; D002460:Cell Line; D017291:Clarithromycin / Q000494:pharmacology; D004917:Erythromycin / Q000031:analogs & derivatives / Q000494:pharmacology; D018922:HL-60 Cells; D006801:Humans; D007875:Legionella / Q000187:drug effects*; D016952:Legionella pneumophila / Q000187:drug effects; D018942:Macrolides; D008826:Microbial Sensitivity Tests; D009000:Monocytes / Q000187:drug effects / Q000382:microbiology; D015575:Roxithromycin / Q000494:pharmacology; D014769:Virginiamycin / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D018942:Macrolides; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; C053853:dirithromycin; D015575:Roxithromycin; D004917:Erythromycin; D017963:Azithromycin; D017291:Clarithromycin