Antimicrobial resistance in coastal waters of Latin America: current knowledge and challenges

Antimicrobial resistance (AMR) is an escalating global health threat, and coastal ecosystems in Latin America are emerging as important yet underexplored reservoirs and transmission pathways. A review of 48 studies (1991–2025) found that resistant bacteria and resistance genes are present in coastal waters across the region, particularly in Brazil, while large areas of Central America and the Caribbean lack data. Multidrug-resistant pathogens of clinical relevance — including E. coli, Enterococcus, Vibrio, and Staphylococcus — as well as genes linked to resistance against β-lactams, sulfonamides, tetracyclines, and even colistin have been detected. These patterns reflect contamination from urban wastewater, hospitals, agriculture, aquaculture, and tourism, compounded by limited wastewater treatment infrastructure. Although molecular and genomic tools are increasingly used, surveillance remains geographically uneven and methodologically inconsistent. The review calls for strengthened environmental monitoring, standardized methods, expanded genomic surveillance, and stronger regional cooperation under a One Health framework to protect both environmental and human health.