Table 4.

Sensitivities of topoisomerase IV and gyrase to fluoroquinolones

DrugIC50(μM)a
E. coliS. aureus
Topoisomerase IVbGyrasecTopoisomerase IVGyrase
Trovafloxacin8.0 (0.53)0.52 (0.02)8.7 (0.29)18.8 (1.7)
Ciprofloxacin5.0 (0.18)0.42 (0.02)13.7 (1.9)25 (0)
Sparfloxacin9.3 (0.17)0.57 (0.02)40 (1.8)22 (1.5)
  • a IC50 drug concentration for half-maximal inhibition of catalytic activity. Values are given as means (standard errors).

  • b Decatenation of kinetoplast DNA.

  • c Supercoiling of relaxed pBR322.