How does antimicrobial resistance arise?
The increased prevalence of bacterial antimicrobial resistance is an outcome of evolution and is a natural phenomenon. One must remember that any population of organisms, including bacteria, naturally includes variants with unusual traits, in this case the ability to fend off the action of an antimicrobial. However, the use of antimicrobials in humans and animals over the past 50 years has inadvertently accelerated the development of resistance by increasing the selection pressure exerted on these microorganisms. Once antimicrobial pressure has been introduced into an environment, resistance can quickly be selected and disseminated4,10. With time, antimicrobial resistance can move from one microbial species to the next and can quickly become established as a normal component of the animal gut flora4,6,7,10. Resistance genes and mechanisms existed long before the introduction of antimicrobials into clinical medicine. Antibiotic resistant bacteria have been isolated from deep within glac
