摘要

    河口沉积物被邻近的沿海工业城市化学污染，但是有机污染物对河口沉积物中抗生素抗性基因（ARG）的影响尚不清楚。我们全面分析了不同季节中河口沉积物中化学污染物（重金属和有机污染物），移动遗传元素（MGE）和ARG之间的复杂相互作用。结果表明，在化学污染的河水的影响下，不同河口沉积物ARG的数量在夏季增加了76.9％–92.3％，在冬季增加了5.9％–35.3％，并且这些ARG的丰度增加了29–5195夏季为冬季，冬季为48–239倍。不同河口的沉积物ARGs丰富，表现出不同的季节趋势。季节变化对河口沉积物ARG的丰富度的影响大于对其多样性的影响。河口沉积物ARGs的多样性与化学污染水平呈正相关。此外，化学污染与MGE呈正相关，而MGE与ARG的丰度呈正相关。这些结果表明，ARGs通过化学污染触发的水平基因转移而富集细菌，从而促进了河口沉积物细菌的多种抗生素耐药性。这些发现对我们理解ARGs在化学污染的河口沉积物中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