Catalan Institute for Water Research (ICRA), Spain; University of Girona (UdG), Spain.
Catalan Institute for Water Research (ICRA), Spain; Grup de Recerca GAiA-Geocamb, Department of Environmental Sciences, University of Girona, Spain.
Sci Total Environ. 2023 Jan 20;857(Pt 1):159202. doi: 10.1016/j.scitotenv.2022.159202. Epub 2022 Oct 5.
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. 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 to μg L. 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 × 10 to 5.6 × 10 gene copies L 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.
本研究调查了在一个农牧业系统环境中 11 个天然泉水中抗生素残留、抗生素抗性基因（ARGs）和抗药性大肠杆菌（AR-E. coli）的发生、迁移及其相关风险。该地区的地下水硝酸盐浓度通常超过 50mg/L，而这里有密集的畜牧业生产。在所监测的 23 种多类抗生素中，四环素和磺胺类残留最为普遍，其浓度范围为 ng/L 到 μg/L。共监测到 5 种 ARGs，赋予了对主要用于畜牧业生产的抗生素类别的抗性。因此，大多数泉水都存在赋予磺胺类（sul1 和 sul2）和四环素（tetW）抗性的基因，以及一个代表人为污染的基因（intI1）。sul1 的丰度最高，绝对浓度范围为 4×10 到 5.6×10 基因拷贝/L 水。还检测到对磺胺类和四环素有抗性的 AR-E. coli，在一些地点的流行率高达约 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. coli 的出现具有较大的季节性变化，主要与水文因素和反应性迁移过程有关。最后，风险评估方法指出，当泉水直接用于人类消费时，地下水环境和人类健康的风险较低，这与抗生素、ARGs 和 AR-E. coli 的存在有关。然而，长期影响不容忽视，必须采取适当措施保护地下水质量。
