Figure 1.

Types of response of protozoan parasites to a drug treatment. The responses of the parasites are shown in different periods of time during the drug treatment. (A) Response of resistant parasites. Susceptible parasites (purple) perish because of the drug treatment; in contrast, due to inherited mutations or molecular mechanisms such as translational reprogramming, resistant parasites (red) can survive and proliferate. (B) Response of persister-like parasites. A persister-like parasite (yellow) enters a dormancy state in the presence of the drug or other stresses and resumes proliferation only when the treatment is finished or the stress is removed. (C) Response of susceptible parasites. Susceptible parasites (purple) lack mechanisms to avoid the effects of the drug and die during the treatment.