TABLE 6.

Effect of AcrAB efflux pump on spermine-dependent antibiotic susceptibility in E. coli

AntibioticMIC (μg/ml)a for indicated strain and treatment
W4573 (parent)N43 (acrA)N818 (ΔacrA)
NoneSpNNoneSpNNoneSpN
Carbenicillin16440.2520.25
Chloramphenicol822<0.0620.12
Tetracycline210.5<0.060.50.12
  • a MIC measurements were done in the absence (none) or presence of 10 mM spermine (SpN).