摘要

       对珠江三角洲地区6个农业点四环素（TC）和磺胺二甲嘧啶（SMZ）的发生、分布及相应的耐药基因（ARGs）进行了研究。分析了两种不同深度（0-10和10-20cm）的灌溉水和灌溉土壤。灌溉水中总TC和SMZ浓度分别为69.3～234ng/L和4.00～58.2ng/L，灌溉土壤中总TC和SMZ浓度分别为5.00～21.9μg/kg和1.30～4.20μg/kg。经过长期田间生活污水和鱼塘污水灌溉后，东莞和深圳鱼塘灌溉土壤中的TC和SMZ及其相应的ARGs显著高于佛山、广州、惠州和中山等生活污水灌溉土壤。灌溉水中的抗生素及其arg含量明显高于灌溉土壤，说明废水是土壤环境中抗生素的主要来源。生活污水和鱼塘废水是重要的抗生素及其精氨酸的贮存库，需要对其进行有效的处理才能排入环境。土壤理化性质、施肥量、灌溉水源和种植方式等因素也影响抗生素浓度和ARG丰度。抗生素残留浓度与灌水和灌水土壤中相应的ARGs呈显著正相关，均随土壤深度的增加而降低，说明环境中抗生素浓度对环境中的微生物具有选择压力。

        The occurrence and distribution of tetracycline (TC) and sulfamethazine (SMZ), and the corresponding antibiotic resistance genes (ARGs) were investigated in six agricultural sites in the Pearl River Delta (PRD) region in southern China. Irrigation water and irrigated soils at two different depths (0-10 and 10-20cm) were analyzed. The total concentrations of TC and SMZ in irrigation water ranged from 69.3 to 234ng/L and from 4.00 to 58.2ng/L, respectively, while the total concentrations of TC and SMZ in irrigated soils ranged from 5.00 to 21.9μg/kg and from 1.30 to 4.20μg/kg, respectively. After long-term irrigation with domestic and fishpond wastewater in the field, the residual TC and SMZ and their corresponding ARGs in soils were significantly higher in fishpond-irrigated soils (Dongguan and Shenzhen) than in domestic wastewater-irrigated soils (Foshan, Guangzhou, Huizhou and Zhongshan). The concentrations of antibiotics and their ARGs were significantly higher in irrigation water than in irrigated soils, which indicated that wastewater was the primary source of antibiotics in the soil environments. The domestic and fishpond wastewater were important repositories of antibiotics and their ARGs, which require effective treatment before their discharge into the environment. Other factors such as soil physicochemical properties, manure application, irrigation water sources and cropping patterns also affect the antibiotic concentrations and ARG abundances. The residual antibiotic concentrations statistically correlated with the corresponding ARGs in irrigation water and irrigated soils, both of which decreased with increasing soil depth, indicating that the concentration of antibiotics in the environment exerted a selection pressure on the microorganisms in the environment.

         https://linkinghub.elsevier.com/retrieve/pii/S0048-9697(17)33427-7