The role of quinolones in staphylococcal infection

Quinolones are highly active against gram-negative aerobic bacteria, especially enterobacteriaceae. The minimum inhibitory concentrations against, e.g. Escherichia coli are between 0.008-0.03 mg/l for ciprofloxacin, 0.06-0.25 mg/l for norfloxacin, 0.031-1.0 mg/l for ofloxacin, and 0.063-2.0 mg/l for pefloxacin. Against Staphylococcus aureus, higher concentrations are required in vitro: 0.12-0.5 mg/l for ciprofloxacin and ofloxacin, 0.25-4 mg/l for norfloxacin, and 0.06-0.5 mg/l for pefloxacin. These compounds have been shown to be active at similar concentrations also against Staphylococcus epidermidis and both oxacillin-sensitive and resistant Staphylococcus aureus and Staphylococcus epidermidis. Clinical experience (in the order of number of patients treated) has been gathered most extensively with ciprofloxacin, followed by pefloxacin, ofloxacin, norfloxacin, and enoxacin.