Truchado Pilar, Oliveira Márcia, Cordero-García Rebeca, Abellán Soler Manuel, Rancaño Amador, García Francisca, Álvarez-Ordóñez Avelino, Allende Ana
Research Group on Microbiology and Quality of Fruit and Vegetables, Food Science and Technology Department, CEBAS-CSIC, Murcia, Spain.
Department of Food Hygiene and Technology and Institute of Food Science and Technology, Universidad de León, León, Spain.
Front Microbiol. 2025 Jun 19;16:1591202. doi: 10.3389/fmicb.2025.1591202. eCollection 2025.
Wastewater reuse for agricultural irrigation is increasingly essential, but it carries potential public health risks due to the dissemination of antimicrobial resistance (AMR). This study evaluates the effectiveness of four tertiary wastewater treatment technologies-peracetic acid (PAA), PAA combined with low-intensity ultraviolet-C (PAA/UV Low), high-intensity UV-C (UV High), and ultrafiltration (UF)-in reducing extended-spectrum β-lactamase-producing (ESBL-) and antimicrobial resistance genes (ARGs) in reclaimed water used for irrigation. The relative abundance of the genes, normalized to the 16S RNA gene present in the water samples, was then estimated to assess whether there is an amplification of these genes during the reuse process in the wastewater treatment plant (WWTP). The results indicate that while all treatments significantly reduced ESBL- (≥3 logs cfu/100 mL) and ARGs (≥ 1.5 logs gc/100 mL), complete elimination was not achieved in any WWTP. Among the treatments, UF demonstrated the highest removal efficiency (≈4 log gc ARG/100 mL), against ARGs, followed by UV High (≈3 log gc ARG/100 mL), whereas PAA and PAA/UV Low were less effective (≈2 log gc ARG/100 mL). The study also found that while absolute ARG levels were reduced, their relative abundance remained stable or showed minimal decline, suggesting a persistent environmental reservoir of resistance genes. Among the ARGs analyzed, the most frequently detected were associated with tetracyclines (), quinolones (), and sulfonamides (), highlighting potential public health concerns. Moreover, multidrug-resistant (MDR) ESBL- isolates were present across all WWTPs, exhibiting resistance to β-lactams, quinolones, tetracyclines, and sulfonamides. Nevertheless, notably low levels of resistance to last-resort antibiotics (tigecycline, colistin, and meropenem) were observed. These findings underscore the critical role of tertiary treatments in mitigating antimicrobial resistance (AMR) risks in water reuse systems. However, the persistence of ARGs in effluents suggests that current WWTP processes require further optimization.
将废水再利用于农业灌溉日益重要，但由于抗微生物药物耐药性（AMR）的传播，这带来了潜在的公共卫生风险。本研究评估了四种三级废水处理技术——过氧乙酸（PAA）、PAA与低强度紫外线-C联用（PAA/UV Low）、高强度紫外线-C（UV High）和超滤（UF）——在减少用于灌溉的再生水中产超广谱β-内酰胺酶（ESBL-）和抗微生物药物耐药基因（ARGs）方面的有效性。然后，将这些基因的相对丰度标准化为水样中存在的16S RNA基因，以评估在污水处理厂（WWTP）的再利用过程中这些基因是否会扩增。结果表明，虽然所有处理均显著降低了ESBL-（≥3个对数cfu/100 mL）和ARGs（≥1.5个对数gc/100 mL），但在任何污水处理厂中均未实现完全消除。在这些处理中，UF对ARGs的去除效率最高（≈4个对数gc ARG/100 mL），其次是UV High（≈3个对数gc ARG/100 mL），而PAA和PAA/UV Low的效果较差（≈2个对数gc ARG/100 mL）。该研究还发现，虽然ARGs的绝对水平有所降低，但其相对丰度保持稳定或略有下降，这表明耐药基因在环境中持续存在。在所分析的ARGs中，最常检测到的与四环素、喹诺酮类和磺胺类有关，突出了潜在的公共卫生问题。此外，所有污水处理厂中均存在多重耐药（MDR）ESBL-分离株，它们对β-内酰胺类、喹诺酮类、四环素类和磺胺类均表现出耐药性。然而，观察到对最后手段抗生素（替加环素、黏菌素和美罗培南）的耐药水平显著较低。这些发现强调了三级处理在减轻水再利用系统中抗微生物药物耐药性（AMR）风险方面的关键作用。然而，ARGs在废水中的持续存在表明，目前的污水处理厂工艺需要进一步优化。
