摘要
      本研究调查了在畜牧业生产密集的农业生态系统环境中，地下水硝酸盐浓度通常高于50 mg L−1的11个天然泉水中抗生素残留、抗生素抗性基因（ARGs）和抗生素抗性大肠杆菌（AR-E.coli）的发生、运输和相关风险。在监测的23种多类抗生素中，四环素和磺酰胺残留最为普遍，检测浓度从ng L−1到μg L−1不等。监测了五种ARG，使其对畜牧生产中主要使用的抗生素类产生耐药性。因此，大多数春季都存在对磺酰胺类药物（sul1和sul2）和四环素类药物（tetW）具有耐药性的基因，以及人为污染的基因替代物（intI1）。sul1含量最丰富，绝对浓度范围为4×102至5.6×106个基因拷贝L−1水。阿拉伯叙利亚共和国。还检测到对磺酰胺类和四环素类药物表现出耐药性的大肠杆菌，在一些地方的流行率高达约40%，但与抗生素残留和ARGs的浓度相关性较差。抗生素、ARGs和AR-E的发生。大肠杆菌具有较大的季节变化特征，主要与水文因素和反应性运输过程有关。最后，风险评估方法指出，当泉水用于人类直接消费时，与抗生素、ARGs和AR-E的发生相关，地下水环境和人类健康的风险都很低。大肠杆菌。然而，长期影响不容忽视，必须采取适当行动保护地下水质量。
Abstract
This study investigates the occurrence, transport, and risks associated to antibiotic residues, antibiotic resistance genes (ARGs) and antibiotic resistant Escherichia coli (AR-E. coli) in eleven natural springs in an agroecosystem environment with intense livestock production, where groundwater nitrate concentration usually sets above 50 mg L−1. Out of 23 multiple-class antibiotics monitored, tetracycline and sulfonamide residues were the most ubiquitous, and they were detected at concentrations ranging from ng L−1 to μg L−1. Five ARGs were monitored, conferring resistance to the antibiotic classes of major use in livestock production. Thus, genes conferring resistance to sulfonamides (sul1 and sul2) and tetracyclines (tetW) as well as a gene proxy for anthropogenic pollution (intI1) were present in most springs. sul1 was the most abundant, with absolute concentrations ranging from 4 × 102 to 5.6 × 106 gene copies L−1 water. AR-E. coli showing resistance to sulfonamides and tetracyclines was also detected, with a prevalence up to approximately 40 % in some sites but with poor correlations with the concentration of antibiotic residues and ARGs. The occurrence of antibiotics, ARGs and AR-E. coli was characterized by large seasonal variations which were mostly associated to both hydrological factors and reactive transport processes. Finally, a risk assessment approach pointed out towards low risk for both the groundwater environment and human health, when spring water is used for direct human consumption, associated with the occurrence of antibiotics, ARGs and AR-E. coli. However, long-term effects cannot be neglected, and proper actions must be taken to preserve groundwater quality.

https://www.sciencedirect.com/science/article/abs/pii/S004896972206301X