Comparative antimicrobial activities of the newly synthesized quinolone WQ-3034, levofloxacin, sparfloxacin, and ciprofloxacin against Mycobacterium tuberculosis and Mycobacterium avium complex.

WQ-3034 is a newly synthesized acidic fluoroquinolone. We assessed its in vitro activity against Mycobacterium tuberculosis and M. avium complex using levofloxacin (LVFX), ciprofloxacin (CPFX), sparfloxacin (SPFX), and KRM-1648 (KRM) as reference drugs. The MICs of these agents were determined by the agar dilution method with 7H11 medium. The MICs at which 50 and 90% of the test strains were inhibited (MIC(50)s, and MIC(90)s, respectively) for the test quinolones for rifampin (RMP)-susceptible M. tuberculosis strains were in the order SPFX < LVFX SPFX >/= LVFX > WQ-3034 > CPFX. The efficacies of all quinolones against intracellular M. tuberculosis organisms were significantly lower in A-549 cells than in MM6-Mphis. WQ-3034 at the MIC caused more marked growth inhibition of intramacrophage M. tuberculosis than did LVFX. These findings indicate that the in vitro anti-M. tuberculosis activity of WQ-3034 is greater than that of CPFX and is comparable to that of LVFX.