Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025
Definition
Multidrug-resistant microbes (MDRs) are pathogens that have acquired resistance to multiple antimicrobial drugs. This resistance makes infections caused by these microbes difficult to treat.
5 Must Know Facts For Your Next Test
MDRs can result from genetic mutations or the acquisition of resistance genes via horizontal gene transfer.
Common examples of MDR microbes include MRSA (Methicillin-resistant Staphylococcus aureus) and VRE (Vancomycin-resistant Enterococci).
Hospital environments are significant reservoirs for MDR microbes due to high antibiotic usage.
Efflux pumps, enzyme production, and target modification are mechanisms used by microbes to resist multiple drugs.
Combating MDR infections often requires the use of combination therapy or last-resort antibiotics like carbapenems.