Table 1.

Overall antimicrobial activities of 15 quinolones and ceftriaxone against 11 B. burgdorferi isolates as determined by colorimetric microdilution technique and conventional subcultures

AntimicrobialConcn (μg/ml)
Test rangeMIC rangeMIC50MIC90MBC rangeMedian MBC
Ceftriaxone0.015–32≤0.015–0.060.030.030.125–41
Nalidixic acid0.5–512128–>512256256≥512>512
Class I
 Norfloxacin0.03–641–16488–>6464
 Pefloxacin0.03–644–64163216–>64>64
Class II
 Fleroxacin0.008–164–>16>16>16≥16>16
 Ofloxacin0.008–161–16488–>16>16
 Ciprofloxacin0.008–160.25–8124–>1616
Class III
 Levofloxacin0.008–160.5–8244–>1616
 Sparfloxacin0.008–160.06–80.5012–>168
 Grepafloxacin0.008–160.06–20.250.502–>168
Class IV
 Gatifloxacin0.008–160.25–20.5014–1616
 Trovafloxacin0.008–160.25–20.5011–1616
 Moxifloxacin0.008–160.25–2124–1616
 Clinafloxacin0.008–160.25–40.5011–168
 Sitafloxacin0.008–160.06–40.250.501–168
 Gemifloxacin0.008–160.03–0.250.060.120.25–164