Table 2.

Inhibition of whole-cell [3H]thymidine incorporation in the S. aureusRN4220 parent and its derivatives

QuinoloneRN4220 parentRN4220-20 (GrlA)RN4220-20-48 (GrlA and GyrA alterationsa)
MIC (μg/ml)IC50 (μg/ml)MIC (μg/ml)IC50 (μg/ml)MIC (μg/ml)IC50 (μg/ml)
Trovafloxacin0.0150.09 (0.01)b0.1250.11 (0.02)11.8 (0.11)
Ciprofloxacin0.250.80 (0.1)11.35 (0.25)825.8 (5.4)
Levofloxacin0.1250.47 (0.02)10.73 (0.14)88.7 (1.5)
Sparfloxacin0.0630.10 (0.01)0.0630.13 (0.02)84.7 (0.4)
  • a GrlA alteration, Ser80 to Phe; GyrA alteration, Ser84 to Leu.

  • b Values in parentheses are standard deviations.