Comparison of the Bactericidal Activity of Moxifloxacin and Levofloxacin against <i>Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli</i> and <i>Klebsiella pneumoniae</i>

In addition to MIC and MBC tests in this study the serum bactericidal activity of 3.1 µg/ml of moxifloxacin or 5.2 µg/ml of levofloxacin was determined against ten susceptible strains of <i>S. aureus, S. epidermidis, E. coli </i>and <i>K. pneumoniae. </i>Moxifloxacin achieved markedly better activity against <i>S. aureus </i>and <i>S. epidermidis </i>as compared to levofloxacin. Activity of moxifloxacin against <i>E. coli </i>and <i>K. pneumoniae </i>was excellent but not superior to levofloxacin. In conclusion both fluorquinolones are highly effective against <i>E. coli </i>and <i>K. pneumoniae, </i>moxifloxacin being superior with respect to gram-positives like <i>S. aureus </i>and <i>S. epidermidis.</i>