作者：Wang, C., Hu, J., Huang, X., Wang, Z. & Lu, S.

Antibiotic resistance remains an escalating threat to global environment and human health. Seasonal water level fluctuations are intrinsic property to floodplain-lakes worldwide, yet their regulatory role on antibiotic resistance genes (ARGs) remains largely overlooked. We presented the first integrative insight of seasonal water level fluctuations, along with land use, physicochemical parameters, and biological factors, in regulating ARGs in the sediments of the largest floodplain-lake in China. Significant spatial variation in ARG profiles emerged only during the dry season (R-2 = 0.258, p < 0.001) between fluctuating water levels zone (FWLZ) and high-water levels zone (HWLZ), with the significantly higher abundance and number of ARGs in FWLZ than of HWLZ (p < 0.05). The water level fluctuation conditions determined the drivers of ARGs: water level was only surpassed by mobile genetic elements (MGEs) in FWLZ by land use, sediment properties, and bacterial communities, but was negligible in HWLZ. Interestingly, our proposed ARG-MGE-antibiotic resistance bacteria (ARB) co-occurrence chains revealed that HWLZ contributed 91.8% of chain numbers, with greater contributions in the wet season (63.9%) compared to the dry season (27.9%). Overall, this study emphasizes divergent responses of ARG profiles and their diffusion risks to seasonal water level fluctuations, which strengthen broadly adoptable approaches for alleviating antibiotic resistance from floodplain-lake.

抗生素耐药性对全球环境与人类健康的威胁不断升级。季节性水位波动是世界各地洪泛平原湖泊的固有属性，但其对抗生素抗性基因（ARGs）的调控作用却在很大程度上被忽视。研究首次综合考察了季节性水位波动及土地利用、理化参数与生物因子对中国最大洪泛平原湖泊沉积物中ARGs的调控作用。结果显示：仅在枯水期，水位波动区（FWLZ）与高水位区（HWLZ）之间的ARG图谱出现显著空间分异（R² = 0.258，p < 0.001），且FWLZ中ARGs的丰度与种类数显著高于HWLZ（p < 0.05）。水位波动条件决定了ARGs的驱动因子构成：在FWLZ中，水位的解释力仅次于可移动遗传元件（MGEs），高于土地利用、沉积物理化性质与细菌群落；而在HWLZ中，水位的影响可忽略不计。有趣的是，我们构建的“ARG—MGE—抗性细菌（ARB）”共现链显示，HWLZ贡献了91.8%的链条数，其中丰水期（63.9%）高于枯水期（27.9%）。总体而言，本研究强调了ARG图谱及其扩散风险对季节性水位波动的差异化响应，为从洪泛平原湖泊减缓抗生素耐药性提供了具有广泛适用性的途径。

（来源：Journal of Hydrology 2026  DOI: 10.1016/j.jhydrol.2026.135469）