An Overview of the Epidemiology of Multidrug Resistance and Bacterial Resistance Mechanisms: What Solutions Are Available? A Comprehensive Review

Antimicrobial resistance has emerged as one of the most critical public health challenges of the 21st century, threatening to undermine the foundations of modern medicine. In 2019, bacterial infections accounted for 13.6% of all global deaths, with more than 7.7 million fatalities directly attributable to 33 bacterial pathogens, most prominently Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumoniae, and Pseudomonas aeruginosa. Resistance mechanisms are multifactorial, encompassing enzymatic degradation, target modification, efflux pump overexpression, reduced membrane permeability, and biofilm formation, often in combination, leading to multidrug-resistant, extensively drug-resistant, and pandrug-resistant phenotypes. Alarmingly, projections estimate that by 2050 AMR could result in over 10 million deaths annually. This comprehensive review synthesizes global epidemiological data, insights into bacterial resistance mechanisms, and emerging therapeutic solutions, including novel antibiotics such as lasso peptides and macrocyclic peptides (e.g., zosurabalpin), naturally derived compounds (e.g., corallopyronin, clovibactin, chlorotonil A), and targeted inhibitors (e.g., Debio 1453 for Neisseria gonorrhoeae). Addressing the AMR crisis requires coordinated international efforts, accelerated drug discovery, and the integration of innovative non-antibiotic approaches to preserve the efficacy of existing therapies and ensure preparedness against future bacterial threats.