Urban landscape lakes with backwater hide higher antibiotic resistance risk than living water

The pollution of antibiotic resistance genes (ARGs) in urban landscape lakes threatens the aquatic ecosystems and public health. However, a comprehensive understanding of the fate of ARGs in different types of park landscape lakes (i.e., backwater and living water) remains deficient. Here, we profiled the distribution, diversity, origin and potential spread risk to human of ARGs in backwater and living water using metagenomics and 16S rRNA gene sequencing. Our results showed higher antibiotic resistance risk presented in backwater due to higher ARG diversity, while higher resistance transfer risk occurred in living water due to higher mobile genetic elements (MGEs) diversity. Source tracking analysis revealed Yellow River water was the main the dominant source of ARGs in both backwater and living water, with an average contribution of 41.06 % and 65.82 %, respectively. Notably, nine high-risk ARGs (such as mdtM and msrA) significantly enriched in human feces, implying possible spread risk from environment to human. Metagenomics binning revealed that MAGs carrying ARGs mainly belong to Actinobacteria, while MAGs carrying MGEs belong to Proteobacteria. Our study highlights the significance of healthy management of park landscape lakes to prevent the spread of resistomes to the public.