Demissie Natnael, Nordin Annika, Simha Prithvi, Conroy Isis, Sun He, Schnürer Anna, Vinnerås Björn, Desta Adey
Department of Energy and Technology, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Institute of Biotechnology, College of Natural and Computational Sciences, Addis Ababa University, Addis Ababa, Ethiopia.
Front Microbiol. 2025 Aug 22;16:1605625. doi: 10.3389/fmicb.2025.1605625. eCollection 2025.
The coexistence of pharmaceuticals and microorganisms in source separated urine poses a risk for the development of antimicrobial resistance (AMR), especially when urine-based fertilizers are applied to soils. While prior studies have investigated pathogen inactivation in source-separated wastewater matrices, few have evaluated the simultaneous fate of antibiotic-resistant bacteria (ARBs) and their corresponding resistance genes (ARGs) in real urine matrices, particularly under alkaline conditions. Here, we studied the inactivation of β-lactamase-producing and vancomycin-resistant and the degradation of their respective ARGs ( and A) in alkalized, unhydrolyzed urine (pH 10.8 and 12.5) treated with UV (65 W low pressure dichromatic mercury lamp at 185/254 nm), hydrogen peroxide (1.25 g L HO), and their combination (UV/HO). UV/HO treatment resulted in >7 log inactivation of both ARBs, with inactivation rate constants of -0.058 log cfu min (, UV) and -0.093 log cfu min (, UV/HO). In contrast, ARG reduction was limited with UV alone and negligible with HO alone. Gene copy reductions of 3 log10 ( , = -0.055 log10 copies min) and 2 log10 (A, = -0.040 log10 copies min) were observed under UV/HO. Notably, brief storage (>3 h) at pH 12.5 achieved similar ARB inactivation and ARG reduction as 80 min of UV/HO treatment at pH 10.8, offering a low-energy alternative for sanitizing source-separated urine.
在源头分离的尿液中，药物与微生物共存会带来产生抗微生物药物耐药性（AMR）的风险，尤其是当将基于尿液的肥料施用于土壤时。虽然先前的研究调查了源头分离的废水基质中病原体的失活情况，但很少有研究评估在实际尿液基质中，尤其是在碱性条件下，抗生素耐药菌（ARB）及其相应耐药基因（ARG）的同时归宿。在此，我们研究了经紫外线（65瓦185/254纳米低压双色汞灯）、过氧化氢（1.25克/升H₂O₂）及其组合（UV/H₂O₂）处理的碱化、未水解尿液（pH值10.8和12.5）中产生β-内酰胺酶的细菌和耐万古霉素细菌的失活情况以及它们各自的ARG（blaTEM和vanA）的降解情况。UV/H₂O₂处理使两种ARB的失活率均超过7个对数，失活速率常数分别为-0.058 log cfu/min（blaTEM，UV）和-0.093 log cfu/min（blaTEM，UV/H₂O₂）。相比之下，单独使用紫外线时ARG的减少有限，单独使用过氧化氢时则可忽略不计。在UV/H₂O₂处理下，观察到blaTEM基因拷贝数减少3个对数10（blaTEM，k = -0.055 log10拷贝/min），vanA基因拷贝数减少2个对数10（vanA，k = -0.040 log10拷贝/min）。值得注意的是，在pH值12.5下短暂储存（>3小时）所实现的ARB失活和ARG减少与在pH值10.8下进行80分钟的UV/H₂O₂处理相似，这为源头分离尿液的消毒提供了一种低能耗的替代方法。
