Table 1.

FQ resistance mutations in E. coli AG100 and its Mar mutant AG112a

Strain or mutantOFL MIC (μg/ml)Fold increase in OFL MICbSubstitution ingyrAMutation in marORmarAexpressionCIP uptake (% of deenergized accumulation)
AG1000.03NoneNoneWild type51
1-AG1000.258D87GNoneWild type43
2-AG100132D87GFrameshift at aa 14 (position 1485 + 1 bp)Overexpression30
3*-AG100264D87GAsp67Tyr (1643G→T)Overexpression9
4*-AG1004128S83L, D87GAsp67Tyr (1643G→T)Overexpression9
AG1120.1254None5-bp deletion (Δ1481–1485)Overexpression25
1-AG112132D87G5-bp deletion (Δ1481–1485)Overexpression24
2-AG112c 4128D87G5-bp deletion (Δ1481–1485)Overexpression12
3-AG112c 8256D87G5-bp deletion (Δ1481–1485)Overexpression9
  • a Abbreviations and symbols: aa, amino acid; Δ, deletion of the bases at the indicated positions; *, mutants were not derived from 2-AG100.

  • b Fold change in MIC compared to the MIC for AG100 (wild type).

  • c Strains have putative mutations at additional unknown loci that affect acrAB.