Exploring the Influence of Environmental Pollution on Antibiotic Resistance in El Alto's water system
Antimicrobial resistance (AMR) is increasingly shaped by environmental contamination in urban aquatic systems. In El Alto, Bolivia, the Seke and Seco rivers receive untreated sewage and metal-rich urban discharges, creating conditions that may promote the persistence and dissemination of antibiotic resistance genes (ARGs). Here, we combined shotgun metagenomics with targeted chemical analyses to characterize the resistome, microbial communities, mobile genetic elements (MGEs), antibiotic residues, and dissolved heavy metals along an urban pollution gradient. Post-urban sites exhibited significantly higher ARG abundance and diversity, together with elevated concentrations of commonly used antibiotics and heavy metals. Resistome structure was strongly associated with MGEs enriched in conjugative and insertion sequence elements, indicating enhanced potential for horizontal gene transfer. Antibiotics and metals significantly explained variation in ARG composition in water samples, supporting the role of co-selection in shaping environmental AMR patterns. In parallel, impacted sites showed enrichment of gut-associated microbial taxa, linking wastewater contamination with resistome expansion. Our findings provide valuable baseline data on antimicrobial resistance in the El Alto river system and highlight the urgent need for improved wastewater treatment, pollution control, and integrated AMR surveillance within a One Health framework.
Antimicrobial resistance (AMR) is increasingly shaped by environmental contamination in urban aquatic systems. In El Alto, Bolivia, the Seke and Seco rivers receive untreated sewage and metal-rich urban discharges, creating conditions that may promote the persistence and dissemination of antibiotic resistance genes (ARGs). Here, we combined shotgun metagenomics with targeted chemical analyses to characterize the resistome, microbial communities, mobile genetic elements (MGEs), antibiotic residues, and dissolved heavy metals along an urban pollution gradient. Post-urban sites exhibited significantly higher ARG abundance and diversity, together with elevated concentrations of commonly used antibiotics and heavy metals. Resistome structure was strongly associated with MGEs enriched in conjugative and insertion sequence elements, indicating enhanced potential for horizontal gene transfer. Antibiotics and metals significantly explained variation in ARG composition in water samples, supporting the role of co-selection in shaping environmental AMR patterns. In parallel, impacted sites showed enrichment of gut-associated microbial taxa, linking wastewater contamination with resistome expansion. Our findings provide valuable baseline data on antimicrobial resistance in the El Alto river system and highlight the urgent need for improved wastewater treatment, pollution control, and integrated AMR surveillance within a One Health framework.
Division of Systems Biology, Department of Life Sciences, SciLifeLab, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden,