(T/F) Resistant strains of bacteria have a selective advantage in individuals who are taking antimicrobials for other reasons.

• A. True
• B. False
• C. Not sure
• D. Both

Answer: (A)

When antimicrobials are used, they create a selective pressure that favors bacteria with resistance mechanisms. If a person is taking an antimicrobial for a different infection, susceptible bacteria in their microbiome are killed or inhibited, while resistant strains survive and multiply. This within-host advantage allows resistant bacteria to become more prevalent in that individual, increasing the chance of persistent colonization or infection and the potential to spread resistance to others. So, resistant strains do gain a selective advantage in people taking antimicrobials for another reason.