摘要
      环境与抗生素耐药性（AR）有关。抗生素抗性基因（ARGs）在废水处理中的有效降解和失活可以成为AR传播的障碍。本研究使用基于紫外线的高级氧化过程（分别为UV254/H2O2和UV254/S2O82），研究了细胞内（i-）和细胞外（e-）质粒编码的tetA、ampR和sul1-ARGs的降解动力学。使用定量聚合酶链式反应（qPCR）对tetA、ampR和sul1的降解进行定量。使用范围在162和1054之间的两个qPCR扩增子观察每个ARG的损伤 bp。使用基于培养的水平基因转化实验来估计pCR的失活动力学™2.1-TOPO-AR质粒。然后比较ARG降解和失活动力学，以了解每种治疗策略在AR缓解中的作用。结果表明，处理的细胞外ARGs降解动力学遵循UV254/S2O82->UV254/H2O2的顺序 > UV254。相对于pH 7和在pH 7下的碱基对比动力学常数在1.86之间 × 109-1.65 × 1011 M−1s−1和2.87 × 109-5.84 × 分别为1011 M−1s−1。所有处理的e-ARGs降解都比i-ARGs的降解高至少2倍。UV254/S2O82-在酸性pH（5-6）下对ARG降解最有效，而UV254/H2O2在pH 7至8之间最有效。富含AT的ampR和较长的qPCR扩增子的降解率较高。UV254/H2O2和UV254/S2O82-的失活率是UV254的2.6倍。一般来说，失活动力学是 ∼ 比短ampR扩增子观察到的降解动力学快8-13倍。这些发现表明，使用短qPCR靶扩增子高估了ARG存在的潜在风险，以及核苷酸组成对ARG损伤的影响。
Abstract
The environment has been implicated with antibiotic resistance (AR). Effective degradation and deactivation of antibiotic resistance genes (ARGs) in wastewater treatment can serve as barriers to AR dissemination. This study investigated the degradation kinetics of intracellular (i-) and extracellular (e-) plasmid-encoded tetA, ampR and sul1 ARGs using UV254, hydroxyl radical () and sulphate radical () UV-based advanced oxidation processes (UV254/H2O2 and UV254/S2O82- respectively). The degradation of tetA, ampR and sul1 was quantified using quantitative polymerase chain reaction (qPCR). The damages to each ARG were observed using two qPCR amplicons ranging between 162 and 1054 bp. Culture-based horizontal gene transformation experiments were used to estimate the deactivation kinetics of pCR™2.1-TOPO AR plasmid. ARG degradation and deactivation kinetics were then compared to understand the roles of each treatment strategy in AR mitigation. Results indicate that extracellular ARGs degradation kinetics of the treatments followed an order UV254/S2O82- > UV254/H2O2 > UV254. The base pair specific kinetic constants with respect to  and  at pH 7 were between 1.86 × 109-1.65 × 1011 M−1s−1 and 2.87 × 109-5.84 × 1011 M−1s−1 respectively. e-ARGs degradation was at least 2-fold higher than i-ARGs degradation for all treatments. UV254/S2O82- was most effective for ARG degradation under acidic pH (5–6) while UV254/H2O2 was most effective between pH 7 and 8. Higher degradation rates were recorded for AT-rich ampR and longer qPCR amplicons. Deactivation rates by UV254/H2O2 and UV254/S2O82- were 2.6-times higher than that of UV254. Generally, deactivation kinetics were ∼ 8–13 times faster than degradation kinetics observed for short ampR amplicon. These findings show an overestimation of the potential risks of ARG presence using short qPCR target amplicons and the impact of nucleotide composition on ARG damage.

https://www.sciencedirect.com/science/article/abs/pii/S1385894722038633