Evolution of antibiotic resistance is linked to any genetic mechanism affecting bacterial duration of carriage
Lehtinen S., Blanquart F., Croucher NJ., Turner P., Lipsitch M., Fraser C.
Significance The relationship between a population’s antibiotic consumption and the frequency of antibiotic resistance among bacteria colonizing that population is not fully understood. Antibiotic resistant and sensitive strains compete for available hosts—we would therefore expect the fitter strain to dominate. Instead, we observe stable coexistence of both strains. In this work, we propose an explanation for this coexistence by showing the fitness advantage of resistance depends on a bacterial strain’s duration of carriage. This finding ties the evolution of resistance to any genetic mechanism affecting duration of carriage. These insights could allow more accurate prediction of future resistance levels and play a role in informing strategies to prevent the spread of resistance.