ABSTRACT
The evolution of antibiotic resistance is defined as a change in the frequency of bacterial genes that affects the way bacteria populations respond to antibiotics, including their ability to grow at different drug concentrations and to persist through antibiotic chemotherapy. Ultimately, these genetic changes lower the effectiveness of antibiotic medicines and increase the length and cost of hospital stays, the probability of treatment failure, and the incidence of severe complications, such as chronic sequelae or death (Carbon 1999; Rubin, Harrington et al. 1999). This chapter focuses on the biological and epidemiological context for the evolution of antibiotic resistance and the policy levers that can be pulled to slow or possibly reverse the spread of resistance.
