Table 2.

Effect of target mutations in strains overexpressing various efflux pumpsa

StrainPump statusgyrA statusLVX MIC (μg/ml)
PAM1020WTb WT0.25
PAM1548WT gyrA (Thr83→Ile)2
PAM1324WT gyrA (Asp87→Tyr)1
PAM1032 nalB WT1
PAM1572 nalB gyrA (Thr83→Ile)8
PAM1481 nalB gyrA (Asp87→Tyr)4
PAM1033 nfxB WT2
PAM1569 nfxB gyrA (Thr83→Ile)16
PAM1482 nfxB gyrA (Asp87→Tyr)8
PAM1034 nfxC WT4
PAM1570 nfxC gyrA (Thr83→Ile)32
PAM1491 nfxC gyrA(Asp87→Tyr)16
  • a The nalB, nfxB, or nfxC mutation was transduced from strain PAM1032, PAM1033, or PAM1034, respectively, into PAM1548 [gyrA(Thr83→Ile)] or PAM1324 [gyrA(Asp87→Tyr)]. All transductants were selected on various combinations of antibiotics in accordance with the specificity of each particular efflux pump. LVX was not used for the selection.

  • b WT, wild type.