[Diversity and Abundance of Antibiotic Resistance Genes in Tailings Ponds]

Antibiotic resistance genes (ARGs) are considered emerging contaminants posing an increasing threat to the ecological environment and global human health. Profiling ARGs in tailings ponds is essential to better understand their spatial and temporal dynamics. In this study, high-throughput quantitative polymerase chain reaction (PCR) techniques were used to investigate the occurrence, diversity, abundance, and distribution of ARGs in a tailings pond. A total of 97, 52, 44, and 56 ARGs were detected in WK0, WK1, WK2, and HS, respectively, with 11, 6, 3, and 6 mobile genetic elements (MGEs) also being detected, respectively. The absolute abundance of ARGs in the pond water ranged from 6.39×10⁷ to 1.75×10⁸ copies·L^-1. Additionally, the abundance of MGEs were higher than ARGs in WK1 and WK2, indicating the potential for horizontal gene transfer (HGT). Furthermore, Cu, TOC, and MGEs were significantly associated with ARGs. Indeed, redundancy analysis (RDA) revealed that Cu, TOC, and MGEs explained 61.64% of the alteration of the ARG profiles, implying their potential roles in the spread and evolution of ARGs in tailings ponds.