Table 2.

Activities of ciprofloxacin and premafloxacin against genetically defined mutants of S. aureus

StrainMutation(s)MIC (μg/ml) of:
CiprofloxacinPremafloxacin
ISP794Wild-type (parent)0.125–0.25 (0.14)a 0.004–0.008 (0.006)
MT5 gyrB142 0.250.008
SS1 gyrA(Ser84Leu)0.25 (0.14)0.008–0.016 (0.011)
MT5224c2 grlA (Ala116Pro)1.00.032
MT5224c3 grlA (Ala116Glu)2.00.032
MT111 grlA (Ala116Glu)1.00.032
MT5224c4 grlA (Ser80Phe)1.00.032
MT5224c9 grlB (Arg470Asp)2.00.032
MT23142 flqB 0.5–1.0 0.008–0.016
EN1252a grlA (Ser80Phe) gyrA(Ser84Leu)320.25
MT1222 grlA (Ala116Glu)gyrA (Ser84Leu) flqB 320.25
RN42208325-4, r, parent0.50.016
EN6 gyrA(Ser84Leu)0.50.016–0.032
EN14 grlB (Arg470Asn) gyrA(Ser84Leu)4.00.125
EN20 grlA(Ser80Phe)4.00.064
EN9 grlA (Ser80Phe)gyrA (Ser84Leu)320.25
  • a Values in parentheses are from experiments using an arithmetic series of drug concentrations.