Disclosed herein are methods of treating a pulmonary bacterial infection comprising bacteria growing under anaerobic conditions using a fluoroquinolone antibiotic. The fluoroquinolone antibiotic may, for example, be levofloxacin or ofloxacin. Also disclosed are methods of inhibiting bacteria growing under anaerobic conditions by exposing the bacteria to an amount of fluoroquinolone antibiotic effective to inhibit growth of said bacteria.
