title: Comparative activity of quinolones, macrolides and ketolides against Legionella species using in vitro broth dilution and intracellular susceptibility testing.
abstract: The comparative in vitro activity of quinolones (trovafloxacin, gemifloxacin, levofloxacin, ciprofloxacin, moxifloxacin and grepafloxacin), ketolides (ABT-773 and telithromycin) and macrolides (clarithromycin, azithromycin and erythromycin) were evaluated against Legionella pneumophila by broth dilution and an HL-60 intracellular model. The MIC90 of the quinolones, clarithromycin and ABT-773 were more than eight times lower than for erythromycin. Telithromycin, ABT-773 and azithromycin had significantly greater intracellular activity against L. pneumophila than erythromycin at 1xMIC and 8xMIC. The rank order of intracellular activity against L. pneumophila serogroup 1 was quinolones>ketolides>macrolides. Clinical trials to determine the clinical efficacy of ketolides for the treatment of Legionnaires' disease are warranted.
authors.affiliation: VA Pittsburgh Healthcare System, VA Medical Center, Infectious Disease Section, University Drive C, Pittsburgh, PA 15240, USA.
authors.forename: Janet E
authors.initials: JE
authors.lastname: Stout
authors.forename: Kelly
authors.initials: K
authors.lastname: Sens
authors.forename: Sue
authors.initials: S
authors.lastname: Mietzner
authors.forename: Asia
authors.initials: A
authors.lastname: Obman
authors.forename: Victor L
authors.initials: VL
authors.lastname: Yu
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D006801:Humans; D048628:Ketolides / Q000494:pharmacology; D007875:Legionella / Q000145:classification / Q000187:drug effects*; D016952:Legionella pneumophila / Q000187:drug effects; D018942:Macrolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests / Q000379:methods; D015363:Quinolones / Q000494:pharmacology*
chemical_list: D000890:Anti-Infective Agents; D048628:Ketolides; D018942:Macrolides; D015363:Quinolones