Fig. 1.
Selection coefficients as functions of MTX concentrations from competition experiments between TMPRand TMPSisogenic strains. The MSC is defined as the concentration where the selection coefficient equals zero. The MSC of E. coli MG1655 harboring (a) two chromosomal folA mutations (MP18–04 and MP18–07) is set to 200 μg/mL, and (b) the MDR pG06-VIM-1 plasmid encoding dfrA12 (MP18–05 and MP18–08) is conservatively set at 25 μg/mL. Dashed lines represent the set MSC, bullets the average selection coefficients based on 12 individual replicates and error bars the standard deviations.