Table 1.

Characterization of E. coli AG100 mutants selected in vitro by ofloxacin from mar knockout andacrAB knockout strains with a single gyrAmutation in the QRDR

Parental or mutant strainMutation in or status ofa:MICb(μg/ml)
gyrAparCmaracrRor acrABacrS oracrEFOFXCIPTETCHLTMPERYCLRAZMCLILNZAMPCXMOXA
AG100wtwtwtwtwt0.060.03240.5>256642412812822>32
1-AG100MKXS83LwtInactivatedwtwt0.50.250.540.5>2566424646422>32
2-AG100MKXS83LwtInactivatedwtwt10.5140.5>2569624966422NT
3-AG100MKXS83LwtInactivatedIS186insertedwt214161NT>25696>256>25644NT
1-AG100AKD87GwtwtInactivatedwt0.060.060.2510.06442281≤10.5
2-AG100AKXD87GwtwtInactivatedIS2inserted0.50.25281>256>256>256>256>25612>32
3-AG100AKXD87GwtwtInactivatedIS2inserted10.54322NTNTNTNTNT14NT
1-DC14PSS83LwtwtInactivatedwt0.060.060.120.50.06442281≤10.5
2-DC14PSS83LwtwtInactivatedIS2inserted21142>256>256>256>256>25624>32
  • a wt, wild type.

  • b OFX, ofloxacin; CIP, ciprofloxacin; TET, tetracycline; CHL, chloramphenicol; TMP, trimethoprim; ERY, erythromycin; CLR, clarithromycin; AZM, azithromycin; CLI, clindamycin; LNZ, linezolid; AMP, ampicillin; CXM, cefuroxime; OXA, oxacillin; NT, not tested.