Fig. 3. Relative exponential growth rates as a function of increasing concentrations.

Growth measured for independent clones selected in a tobramycin and b tetracycline for which copy numbers (CN) are 2.3 and 5.1 (in yellow circles and yellow triangles, respectively) and 3.5 and 9.4 (in blue circles and blue triangles), and the heteroresistant parental isolates with single copy (E. coli DA33135 heteroresistant to tobramycin and S. Typhimurium DA34827 heteroresistant to tetracycline, represented in gray). The growth rates are relative to the growth of the heteroresistant parental isolate in the absence of antibiotic. The standard deviations of three biological replicates are reported (n = 3).