An in vitro Investigation of the Intraphagocytic Bioactivity of Difloxacin, Ciprofloxacin, Pefloxacin and Fleroxacin

In this study the intraphagocytic bioactivity of difloxacin, ciprofloxacin, pefloxacin and fleroxacin was investigated using human neutrophils and a combination of a radioassay, a colony-counting method and a fluorescence microassay which enables us to differentiate between intracellular bacteriostatic and bactericidal mechanisms. Staphylococcus aureus and Listeria monocytogenes were used as the test intraphagocytic microbial pathogens. It was found that difloxacin, ciprofloxacin and to a lesser extent pefloxacin and fleroxacin possess intracellular bacteriostatic activity for S. aureus and L. monocytogenes.