Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education; College of Water Sciences, Beijing Normal University, No 19, Xinjiekouwai Street, Beijing, 100875, China.
Engineering Research Center of Groundwater Pollution Control and Remediation, Ministry of Education; College of Water Sciences, Beijing Normal University, No 19, Xinjiekouwai Street, Beijing, 100875, China.
Environ Pollut. 2023 Dec 1;338:122661. doi: 10.1016/j.envpol.2023.122661. Epub 2023 Sep 29.
Sewage treatment plant (STP) effluents are important contributors of antibiotic resistance (AR) pollution in rivers. Effluent discharging into rivers causes resistome coalescence. However, their mechanisms and dynamic processes are poorly understood, especially for the effects of dilution, diffusion, and sunlight-induced attenuation on coalescence. In this study, we have constructed microcosmic experiments based on in-situ investigation to explore these issues. The first batch experiment revealed the effects of dilution and diffusion. The coverage of water coalesced resistomes ranged 66.26∼152.18 × /Gb and was positively correlated with effluent volume (Mann-Kendall test, p < 0.01). Principal coordinate analysis (PCoA) and source tracking analysis demonstrated that dilution and diffusion stepwise reduced AR pollution. The second batch experiment explored the temporal dynamics and sunlight attenuation on coalesced resistomes. Under natural light, the coverage and diversity of water resistomes posed decreasing trends, primarily attributed to drastic erasure of effluent traces. The proportion of effluent-specific ARGs in coalesced resistomes significantly declined over time (Spearman's r = -0.83 and -0.94 in coverage and richness). While under dark condition, the coverage and diversity increased. Sunlight radiation intensified the interactions between water and sediment resistomes, as evidenced by more shared ARGs and less dissimilarities across niches. Network analysis, metagenome-assembled genome (MAG) analysis and variation partitioning analysis (VPA) showed that microbiome controlled resistome coalescence, explaining 56.5% and 58.4% of resistomes in water and sediment, respectively. Biotic and abiotic factors synergistically explained 40% of water resistomes. This study offers a comprehensive understanding of AR transmission and provides theoretical bases for grasping AR pollution and developing effective suppression strategies.
污水处理厂（STP）废水是河流中抗生素抗性（AR）污染的重要贡献者。废水排入河流会导致抗性组聚合。然而，其机制和动态过程尚不清楚，特别是对于稀释、扩散和阳光诱导衰减对聚合的影响。在这项研究中，我们基于原位调查构建了微观实验来探索这些问题。第一批实验揭示了稀释和扩散的影响。合并的水抗性组的覆盖率范围为 66.26∼152.18×/Gb，与废水体积呈正相关（Mann-Kendall 检验，p<0.01）。主坐标分析（PCoA）和来源追踪分析表明，稀释和扩散逐步减少了 AR 污染。第二批实验探索了合并的抗性组的时间动态和阳光衰减。在自然光下，水抗性组的覆盖率和多样性呈现下降趋势，主要归因于废水中的痕量物质的急剧消失。随着时间的推移，合并的抗性组中废水特异性 ARGs 的比例显著下降（覆盖率和丰富度的 Spearman 相关系数分别为-0.83 和-0.94）。而在黑暗条件下，覆盖率和多样性增加。阳光辐射加剧了水和沉积物抗性组之间的相互作用，表现在更多的共享 ARGs 和更少的生态位差异。网络分析、宏基因组组装基因组（MAG）分析和变异分解分析（VPA）表明，微生物组控制了抗性组的聚合，分别解释了水和沉积物中 56.5%和 58.4%的抗性组。生物和非生物因素协同解释了水抗性组的 40%。本研究提供了对抗生素抗性传播的全面理解，并为掌握抗生素污染和开发有效的抑制策略提供了理论基础。
