The ability of microbes to withstand drugs that once killed or inhibited them
Explanation
Antimicrobial resistance (AMR) describes the capacity of bacteria, viruses, fungi and parasites to survive exposure to medicines that were previously effective against them. It occurs when microorganisms develop the ability to defeat medicines designed to kill them【789199571224237†L87-L90】. Genetic mutations and horizontal gene transfer can alter drug targets, increase efflux of the drug or produce enzymes that inactivate it. Overuse of antibiotics, antivirals, antifungals and antiparasitic drugs in human and veterinary medicine and agriculture creates selective pressure that favours resistant strains. The AMR Narrative emphasises that antimicrobial resistance is a global public health threat【789199571224237†L96-L99】. Factors contributing to AMR include natural resistance in some organisms, patients taking medicines at sub‑therapeutic doses or stopping therapy too soon, and the widespread use of similar compounds in crop protection【789199571224237†L135-L151】. Poor diagnostic capacity also leads to inappropriate therapy, further accelerating resistance.
Examples and impact
Resistant pathogens compromise the treatment of common infections. Methicillin‑resistant Staphylococcus aureus, vancomycin‑resistant enterococci and extended‑spectrum β‑lactamase–producing Enterobacteriaceae cause serious hospital‑acquired infections and have limited therapeutic options【816752105985831†L139-L147】. Multidrug‑resistant tuberculosis, artemisinin‑resistant malaria and HIV strains resistant to first‑line antivirals exemplify AMR in other microbial groups. Fungi such as Candida auris and Aspergillus fumigatus have evolved resistance to multiple antifungal classes【789199571224237†L155-L161】. The economic burden of AMR includes prolonged hospital stays, need for expensive second‑line drugs and increased mortality. Combatting AMR requires coordinated stewardship programmes, surveillance, infection prevention, vaccination and investment in new treatments.
AMR jeopardises decades of progress in infectious disease control. Rational prescribing, adherence to treatment, and reducing non‑essential use of antimicrobials in farming are key strategies to slow its spread.
Related Terms: Antibiotic Resistance, Antifungal Resistance, Antiviral Resistance, Antimicrobials, Anthelmintic Resistance