Title : Environmental and genetic drivers of global antibiotic resistance: Impact on clinical practice and public health
Abstract:
Antibiotic resistance in clinical practice is driven by a complex interaction between genetic mechanisms within microorganisms and environmental factors that exert selective pressure on bacterial populations. Genetic drivers include spontaneous chromosomal mutations that alter antibiotic target sites, decrease membrane permeability, or enhance eflux pump activity, thereby reducing antibiotic effectiveness. Resistance genes may also spread rapidly among bacteria through horizontal gene transfer mechanisms such as transformation, transduction, and conjugation, often mediated by plasmids, transposons, and integrons that carry multiple resistance determinants. Biofilm formation further promotes resistance by limiting antibiotic penetration and facilitating gene exchange among bacteria. Environmental drivers play an equally important role, with inappropriate antibiotic use in humans being the most significant factor. Excessive prescribing, unnecessary treatment of viral infections, improper dosing, and prolonged courses create strong selective pressures favoring resistant organisms. Healthcare settings, particularly hospitals and intensive care units, contribute to the emergence and spread of multidrug-resistant pathogens because of high antimicrobial consumption, invasive procedures, prolonged hospitalization, and cross-transmission between patients. Beyond clinical settings, the use of antibiotics in agriculture and animal husbandry, environmental contamination from wastewater and pharmaceutical waste, inadequate sanitation, and increasing international travel and globalization have facilitated the dissemination of resistance genes across ecosystems and populations. Patient-related factors such as recurrent antibiotic exposure, immunosuppression, diabetes, indwelling medical devices, and previous colonization with resistant organisms further increase the risk of infection with resistant pathogens. Emerging research has also identified the gut microbiome resistome, stress-induced mutagenesis, quorum sensing, persister cell formation, and epigenetic regulation as important contributors to resistance evolution. Collectively, these genetic and environmental factors demonstrate that antibiotic resistance is an ecological and evolutionary phenomenon rather than solely a microbiological problem, underscoring the need for a comprehensive One Health approach that integrates human medicine, veterinary medicine, agriculture, microbiology, and environmental sciences to preserve the effectiveness of existing antimicrobial agents and improve patient outcomes. In summary, antibiotic resistance no longer emerges only in hospitals. It is now fueled by ecological reservoirs, mobile genetic elements, and global transmission networks, forcing medicine and public health to adopt a One Health, genomics-guided approach to treatment, robust surveillance, prevention-focused strategy, and policy.
