Kinetic bactericidal activity of telithromycin, azithromycin and clarithromycin against respiratory pathogens.
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.
Drago
L
L
Laboratory of Clinical Microbiology, Department of Clinical Sciences L. Sacco, University of Milan, Italy. lorenzo.drago@unimi.it
De Vecchi
E
E
Nicola
L
L
Legnani
D
D
Gismondo
M R
MR
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
D000900:Anti-Bacterial Agents; D048628:Ketolides; D011500:Protein Synthesis Inhibitors; D017963:Azithromycin; D017291:Clarithromycin; C106791:telithromycin