TABLE 4

Inhibitory activities of lascufloxacin against DNA gyrase and topoisomerase IV of S. aureus and human topoisomerase II

DrugIC50 (μg/ml)aIC50 ratio of QR to wild-type strain
Wild-type DNA gyraseQRb DNA gyraseWild-type topoisomerase IVQRb topoisomerase IVHuman topoisomerase IIDNA gyraseTopoisomerase IV
Lascufloxacin1.7 ± 0.417 ± 30.73 ± 0.062.8 ± 0.3>2400103.8
Levofloxacin16 ± 61300 ± 1002.8 ± 0.986 ± 191400 ± 1008131
Garenoxacin11 ± 1420 ± 801.9 ± 0.627 ± 1750 ± 2803814
Ciprofloxacin25 ± 5>12001.8 ± 0.769 ± 7>1100>4838
  • a n = 3, average ± SD.

  • b QR, quinolone resistant. Mutations of DNA gyrase and topoisomerase IV were GyrA Ser84Leu and ParC Ser80Phe, respectively.