Antibiotics play a key role in human health by helping to combat bacterial infection, but bacteria can evolve resistance to antibiotics patients rely on. By counting bacteria and sequencing their genome, the researchers could assess how quickly the different populations evolved resistance to the antibiotic and the genetic mutation that causes the resistance. Researchers suggest the reason for this fast mutation rate could be that the pmrB gene is associated with the human immune system. A rapid mutation rate would help the bacterium to survive by adapting to the fluctuating changes in the immune system. When the antibiotic was withdrawn, the pathogen populations quickly lost resistance as a consequence of the high mutation rate.
