The activity of ofloxacin against methicillin-resistant Staphylococcus aureus.

The return of multiresistant Staphylococcus aureus strains and the appearance of methicillin-resistant strains resistant as well to rifampin and fusidic acid increase the need for new agents to treat infections caused by such strains. Ofloxacin susceptibility of 109 selected methicillin-resistant staphylococci (with MIC90 of 1,000 mg/l for methicillin, 1.3% being resistant to gentamicin with MICs ranging from 25 to 100 mg/l, chloramphenicol MICs ranging from 25 to 100 mg/l and resistant to beta-lactam-antibiotics and clindamycin), was determined by an agar dilution method. MICs of ofloxacin for methicillin-resistant staphylococci ranged from 0.09 to 0.78 mg/l, with an MIC90 of 0.39 mg/l. The in vitro results suggest a possible clinical role for ofloxacin in infections caused by methicillin-resistant staphylococci. However, further investigations are needed.