title: Kinetic bactericidal activity of telithromycin, azithromycin and clarithromycin against respiratory pathogens.
abstract: The present study assessed the comparative in vitro killing kinetics of telithromycin, azithromycin and clarithromycin. Minimal inhibitory concentrations (MIC) and minimal bactericidal concentrations (MBC) were determined against Streptococcus pneumoniae, beta-haemolytic streptococci, Haemophilus influenzae and Moraxella catarrhalis strains characterized by different susceptibilities to beta-lactams and macrolides. For each bacterial species, representative strains were chosen for time-kill studies. Telithromycin showed high activity against all the tested strains with MIC ranging from < or = 0.004 to 0.5 mg/L for streptococci, from 0.008 to 8 mg/L for H. influenzae, and from 0.008 to 0.5 mg/L for M. catarrhalis. In time-kill studies, telithromycin showed an overall superior bactericidal activity in respect to macrolides, particularly against resistant strains. In conclusion, telithromycin proved to possess bactericidal activity against a wide range of respiratory pathogens, including strains resistant to common macrolides.
authors.affiliation: Laboratory of Clinical Microbiology, Department of Clinical Sciences L. Sacco, University of Milan, Italy. lorenzo.drago@unimi.it
authors.forename: L
authors.initials: L
authors.lastname: Drago
authors.forename: E
authors.initials: E
authors.lastname: De Vecchi
authors.forename: L
authors.initials: L
authors.lastname: Nicola
authors.forename: D
authors.initials: D
authors.lastname: Legnani
authors.forename: M R
authors.initials: MR
authors.lastname: Gismondo
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017963:Azithromycin / Q000494:pharmacology*; D017291:Clarithromycin / Q000494:pharmacology*; D006193:Haemophilus influenzae / Q000187:drug effects*; D048628:Ketolides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*; D013291:Streptococcus / Q000187:drug effects*; D013296:Streptococcus pneumoniae / Q000187:drug effects; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents; D048628:Ketolides; D011500:Protein Synthesis Inhibitors; D017963:Azithromycin; D017291:Clarithromycin; C106791:telithromycin