Bacterial growth rate without density-dependent effects for different antibiotic concentrations.

The curves show the effect of a biostatic (bs) and biocidal (bc) drug. For a biostatic drug, we plot max(βj − αj(c), 0) − δj (instead of the expression written on the y-axis label, βj − δj − αj(c)). For clarity, we only show the biostatic drug effect for the sensitive strain (black dot-dashed line), and not for the resistant strains. The effect of a biostatic drug on the resistant strains would yield a minimal growth rate at −δR. Parameters for the sensitive antibiotic response curve are motivated by estimates for ciprofloxacin from [35]: βS = 2.5 per day (d−1), βR = 2.25 (d−1), δS = δR = 0.5 (d−1), κ = 1.1, ψj,min = −156 × log(10) (d−1), ψj,max = βj − δj (d−1).