Activity of moxifloxacin against mycobacteria.

Moxifloxacin is an 8-methoxyquinolone compound with activity against a wide range of bacteria. We tested its activity in comparison with four other quinolones and isoniazid against clinical isolates of mycobacteria. It proved to be the most active of the quinolones tested against Mycobacterium tuberculosis (MIC90 0.25 mg/L), Mycobacterium avium-intracellulare (MIC90 1.0 mg/L), Mycobacterium kansasii (MIC90 0.06 mg/L) and Mycobacterium fortuitum (MIC90 1 mg/L). These data indicate that moxifloxacin merits further study as an antimycobacterial agent.