Emergence of double resistance as a function of the effect of stress on HGT. Double resistance emergence for each strategy is plotted, in log scale, as a function of θ, the effect of stress on HGT. Mixing is plotted in green, cycling in blue, and combining in red. We see that stress-induced HGT changes the efficiency of the strategies so that cycling is the most efficient strategy for a wide range of θ values - note that lower emergence indicates a more efficient strategy. Panel A shows results for ϕ = 1, whereas in panel B ϕ = 0. We can see that the double resistance emergence for mixing indeed increases dramatically for ϕ = 1 in comparison with ϕ = 0 , matching the intuitive explanation (see text). An intersection of the curves implies that the preference between two strategies should change. The mean is taken over 600 days, where the length of each cycle in the cycling strategy is 200 days. Other parameter values: β = 0.9, γ = 0.03, m = 0.1, λs = 0.1, , , τ = 0.5, C = 1 (note that changing C will just rescale the horizontal axis, so its value is arbitrary). HGT, horizontal gene transfer.
Obolski and Hadany BMC Medicine 2012 10:89 doi:10.1186/1741-7015-10-89