摘要

     河口沉积物通常受到邻近沿海工业城市的化学污染，但有机污染物对河口沉积物中抗生素耐药基因（ARGs）的影响尚不清楚。本文综合分析了河口沉积物中化学污染物（重金属和有机污染物）、可移动基因元件（MGEs）和ARGs在不同季节的复杂相互作用。结果表明，受化学污染河水的影响，不同河口沉积物中的ARG数量夏季增加76.9%～92.3%，冬季增加5.9%～35.3%；夏季增加29～5195倍，冬季增加48～239倍。不同河口沉积物ARG的丰度呈现不同的季节变化趋势。季节变化对河口沉积物arg丰度的影响大于对其多样性的影响。河口沉积物ARGs多样性与化学污染水平呈正相关。此外，化学污染与MGEs呈正相关，MGEs与ARG丰度呈正相关。这些结果表明，通过化学污染引发的水平基因转移导致ARG富集在细菌中，促进了河口沉积物细菌的多重耐药性。这些发现对我们了解受化学污染的河口沉积物中ARGs的分布和传播具有重要意义。

      Estuary sediments are chemically contaminated by adjacent coastal industrial cities, but the impact of organic pollutants on antibiotic resistance genes (ARGs) in estuarine sediments is unknown. We comprehensively analyzed the complex interactions between chemical pollutants (heavy metals and organic pollutants), mobile genetic elements (MGEs), and ARGs in estuarine sediments during various seasons. The results indicate that under the effects of the chemically polluted river water, the number of different estuarine sediment ARGs increased by 76.9%–92.3% in summer and 5.9%–35.3% in winter, and the abundance of these ARGs increased by 29–5195 times in summer and 48–239 times in winter. The abundance of sediment ARGs in distinct estuaries showed different seasonal trends. Seasonal changes had a greater impact on the abundance of estuarine sediment ARGs than on their diversity. The diversity of estuarine sediment ARGs was positively correlated with the chemical pollution levels. Furthermore, chemical pollution was positively correlated with MGEs, and MGEs were correlated with ARG abundance. These results indicate that ARGs are enriched in bacteria via horizontal gene transfer triggered by chemical pollution, promoting multi-antibiotic resistance in estuarine sediment bacteria. These findings have implications for our understanding of the distribution and propagation of ARGs in chemically polluted estuarine sediments.

      https://www.sciencedirect.com/science/article/abs/pii/S0304389419311185