Selection of Resistant Bacteria at Very Low Antibiotic Concentrations
Figure 4
Competition experiments with low initial frequencies of resistant mutants.
Competition experiments at different concentrations of antibiotics and different starting fractions of resistant mutants. (A) Initial ratio of susceptible to resistant mutants 10∶1. (B) Initial ratio of susceptible to resistant mutants 102∶1. (C) Initial ratio of susceptible to resistant mutants 103∶1. (D) Initial ratio of susceptible to resistant mutants 104∶1. (E) Calculated selection coefficients as a function of antibiotic concentrations. Fig. A to D are each based on one single competition experiment while E is calculated from the selection coefficients of 24 independent competitions with four different starting fractions of resistant mutants (Table S3 in Text S1). Standard errors of the mean are indicated.