Interactions of the oxygen-dependent antimicrobial system of the human neutrophil with difloxacin, ciprofloxacin, pefloxacin and fleroxacin in the intraphagocytic eradication of Staphylococcus aureus.

The effect of the O2-dependent antimicrobial systems of the human neutrophil on the intraphagocytic activity of difloxacin, ciprofloxacin, pefloxacin and fleroxacin was determined by use of a radioassay with Staphylococcus aureus as the test organism. The fluoroquinolones exhibited good intraphagocytic activity with normal neutrophils. However the intracellular bioactivities of the four antimicrobial agents were substantially less in tests with neutrophils from two patients with chronic granulomatous disease. These observations suggest a synergic interaction between fluoroquinolones and the O2-dependent antimicrobial systems of phagocytes in the eradication of intracellular microbial pathogens.