Risk assessment of antibiotic-resistant bacteria in global lakes and their hotspots

Freshwater lakes are crucial hotspots that have fueled the global antimicrobial resistance crisis. However, the distribution patterns and health risks of antibiotic-resistant bacteria (ARB) in lakes remain largely unexplored at the global scale. In this study, we comprehensively examined 1268 metagenomic samples from lakes globally and identified 12,866 ARBs spanning 28 phyla. Furthermore, based on the co-carriage of resistance genes, mobile genetic elements, and virulence factors, we developed a three-tiered risk framework. This framework distinguishes a critical-risk group comprising six species (belonging to Enterobacteriaceae, Aeromonadaceae, and Pseudomonadaceae) that are phylogenetically closely related to known pathogens, exhibiting the highest resistance, mobility, and pathogenic potential. Geographically, these critical-risk ARBs are primarily concentrated in low-latitude lakes (Amazon Basin, Central Africa, South/Southeast Asia, and Central America). Using machine learning, we identified temperature and wind speed as the primary driving factors. From a One Health perspective, our results inform a clear action plan and pinpoint low-latitude lakes as the priority targets for surveillance. This highlights the urgent need to include ARB risk stratification in security frameworks for global aquatic ecology.