[The effect of antimicrobial use on emergence and selection of resistance].

There is a direct relationship between antibiotic use and resistance. A two-stage model for the development of antibiotic resistance has been suggested: antibiotic resistance is first induced (emergence) and then followed by its spread, facilitated by antibiotic selection pressure. Importantly, the decline in resistance after treatment cessation or a reduction in the volume of antibiotic use is much slower than its emergence. Excessive antibiotic use has individual and ecologic effects that can alter clinical practice and increase treatment costs.