FIG. 5.

Infectious bacteria under risk of antibiotic treatment. As stated in the text, in some cases infections are extremely acute (black line), so that the host is damaged (and even killed) before an antibiotic treatment is implemented. Other infections present no symptoms and have subclinical manifestations, so that they are not treated even if they occur for long periods of time (light gray line). Only infectious bacteria that produce clinically relevant symptoms and are present long enough to be treated (dark gray line) are under antibiotic selective pressure.