In vitro activity of gatifloxacin, a new fluoroquinolone, against 204 anaerobes compared to seven other compounds

The activity of gatifloxacin, a new fluoroquinolone derivative, was compared with the activities of ciprofloxacin, levofloxacin, amoxicillin, amoxicillin-clavulanate, imipenem, clindamycin and metronidazole against 204 anaerobes isolated from clinical specimens, by MIC determination, using the reference agar dilution method. When determining the overall activity against anaerobes, the MIC50/90 (mg/L) values were amoxicillin 16/>64, amoxicillin-clavulanate 0.125/1, imipenem 0.25/0.5, clindamycin 0.5/>256, metronidazole 1/8, ciprofloxacin 2/32, levofloxacin 1/8 and gatifloxacin 0.5/4. The broad in vitro spectrum of gatifloxacin is promising for the treatment of mixed anaerobic infections, especially those of the respiratory tract, ear, sinus, skin and soft tissues, and bite wounds. These data suggest that gatifloxacin may have a clinical role in the treatment of infections in which anaerobic pathogens are involved.