Mechanisms of Action and Antimicrobial Resistance: A Comprehensive Review of Antibacterials and Antifungals and Microbial Evolution

Abstract

The emergence and evolution of antimicrobial agents have revolutionized modern medicine, enabling the effective treatment of bacterial and fungal infections. This article reviews the main mechanisms of action of antibacterial and antifungal agents, including inhibition of cell wall synthesis, protein synthesis, plasma membrane damage, and inhibition of nucleic acids and essential metabolites. The various mechanisms of microbial resistance are also discussed, such as the production of inactivating enzymes, changes in membrane permeability, modification of target sites, efflux systems, and biofilm formation. Microbial evolution through mutations and horizontal and vertical gene transfer is also addressed, highlighting natural selection as a driver of resistance. The conclusion is that the indiscriminate use of antimicrobials has accelerated the emergence of resistant strains, urgently requiring new therapeutic strategies and greater awareness of the rational use of these drugs.