Urban Water Supply and Drainage System Safety and Energy Saving Engineering Technology Center, Fujian University of Technology, Fuzhou, 350118, China.
Marine Resources and Environment Research Center, Zhejiang Mariculture Research Institute, Wenzhou, 325005, China.
Environ Pollut. 2021 Jul 15;281:116980. doi: 10.1016/j.envpol.2021.116980. Epub 2021 Mar 22.
Coastal tourist and industrial cities are most likely to have differential effects on the distance dilution of antibiotic resistance genes (ARGs) in an estuary system. This study used high-throughput fluorescence quantitative polymerase chain reaction to identify sediment ARGs in two typical estuaries of coastal tourist and industrial cities (Xiamen and Taizhou) in China. The distance dilution of ARGs and its relationship with key environmental factors were analysed. The results indicated that along the river inlet towards the sea, the distance dilution effect on ARG abundance in estuary sediments of Taizhou was approximately double that in Xiamen, and the macrolide, lincosamide, and streptogramin B (MLSB) and vancomycin genes were replaced by the fluoroquinolone, quinolone, florfenicol, chloramphenicol, and amphenicol (FCA) and β-lactam genes in Taizhou, whereas β-lactam genes succeeded the MLSB and sul genes in Xiamen. The abundance and number of ARGs and mobile genetic elements (MGEs) were positively correlated with the particle size and total organic carbon (TOC) contents of sediments, whereas they were negatively associated with the oxidation and reduction potential (E) and pH of sediments, as well as the seawater salinity. The sediment particle size (SPZ) was the dominant physicochemical factor affecting the abundance of ARGs (r = 0.826, p < 0.05) and MGEs (r = 0.850, p < 0.01). These findings suggest that although the distance dilution effect on the ARG abundance of estuary sediments of the industrial city is greater than that of the tourist city, the larger SPZ, higher TOC content, and lower salinity, pH, and E in estuary regions adjacent to the industrial city can more significantly facilitate the proliferation and propagation of ARGs in the sediments.
沿海旅游和工业城市最有可能对河口系统中抗生素抗性基因（ARGs）的距离稀释产生差异影响。本研究使用高通量荧光定量聚合酶链反应（PCR）鉴定了中国两个典型沿海旅游和工业城市（厦门和台州）河口沉积物中的 ARG。分析了 ARG 的距离稀释及其与关键环境因素的关系。结果表明，沿着河流入海口向海的方向，台州河口沉积物中 ARG 丰度的距离稀释效应约为厦门的两倍，而大环内酯、林可酰胺和链阳菌素 B（MLSB）和万古霉素基因被氟喹诺酮、喹诺酮、氟苯尼考、氯霉素和安普霉素（FCA）和β-内酰胺基因取代，而在厦门，β-内酰胺基因取代了 MLSB 和 sul 基因。ARG 和移动遗传元件（MGEs）的丰度和数量与沉积物的粒径和总有机碳（TOC）含量呈正相关，而与沉积物的氧化还原电位（E）和 pH 值以及海水盐度呈负相关。沉积物粒径（SPZ）是影响 ARG 丰度的主要理化因素（r = 0.826，p < 0.05）和 MGEs（r = 0.850，p < 0.01）。这些发现表明，尽管工业城市河口沉积物中 ARG 丰度的距离稀释效应大于旅游城市，但工业城市附近河口区较大的 SPZ、较高的 TOC 含量以及较低的盐度、pH 值和 E 更有利于沉积物中 ARGs 的增殖和传播。
