Fig. 4: Stronger noises may lead to earlier appearance of drug-resistance.

a–c Distribution of the number of effective antibiotic treatments at varying levels of noise intensity (Ω = 2000, 5000, and 10,000). The bars represented the distribution of effective treatment numbers in stochastic simulations. We used a green bar to indicate cases where resistance does not emerge even after 25 infections. The red dashed line represented the average number of infections leading to resistance in stochastic simulations (excluding cases where resistance does not emerge after 25 infections). The orange dashed line represented the number of effective treatment cycles in the deterministic model. d The time course of pathogens illustrating the development of drug resistance during the 5th treatment. Panel (e) presented the amount of sensitive and resistant pathogens prior to each infection cycle, corresponding to the scenario shown in Panel (d). f The diagram provided an example of a scenario where no drug resistance develops. The upper and lower panels demonstrated the changes in the number of sensitive and resistant pathogens with repeated treatments, respectively. The red, cyan, and blue curves represented the infection, antibiotic-treatment, and recovery courses, respectively. All microbial populations shown in the figure were normalized to Ω.