Fate of Antibiotic Resistance Genes and Class 1 Integrons in Soil Microcosms Following the Application of Treated Residual Municipal Wastewater Solids
Fate of Antibiotic Resistance Genes and Class 1 Integrons in Soil Microcosms Following the Application of Treated Residual Municipal Wastewater Solids
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DOI：
10.1021/es501098g
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发表时间：
2014-05-20
影响因子：
11.4
通讯作者：
LaPara, Timothy M.
中科院分区：
文献类型：
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作者：
Burch, Tucker R.;Sadowsky, Michael J.;LaPara, Timothy M.
大量的抗生素抗性基因（ARGs）随处理后的城市污水残渣一起排放，随后施用于土壤。这项工作的目的是确定经过处理的废水固体模拟土地应用后，ARGs和1类整合子的衰减率。在两个独立的实验中，将两个全规模处理厂处理后的残余固体应用于三份土壤微观环境。实验1研究了20、40和100 g kg（-1）残余固体对沙质土壤的加载率，而实验2研究了40 g kg(-1) I对粉质壤土的加载率。采用实时聚合酶链式反应对5个ARGs (erm(B)、sull、tet(A)、tet（W)、tet(X)）、1类整合子整合酶（intI1）、16S rRNA基因、所有拟杆菌属的16S rRNA基因和人类特异性拟杆菌属的16S rRNA基因进行定量。ARGs和intI1的半衰期在13 d (erm（B)，实验1,100 g kg(-1)）和81 d （intI1，实验1,40 g kg(-1)）之间变化，具有统计学意义（P < 0.05）。这些动力学速率比以前报道的用于处理废水固体的单元操作（例如厌氧消化）要慢得多。本研究表明，以减少ARGs排放为明确目标的城市污水处理设施的设计和运行应侧重于在处理设施内使用技术，而不是依赖于土地使用后的衰减。
Substantial quantities of antibiotic resistance genes (ARGs) are discharged with treated residual municipal wastewater solids and subsequently applied to soil. The objective of this work was to determine the decay rates for ARGs and class 1 integrons following simulated land application of treated wastewater solids. Treated residual solids from two full-scale treatment plants were applied to sets of triplicate soil microcosms in two independent experiments. Experiment 1 investigated loading rates of 20, 40, and 100 g kg(-1) of residual solids to a sandy soil, while experiment 2 investigated a loading rate of 40 g kg(-1) I to a silty-loamy soil. Five ARGs (erm(B), sull, tet(A), tet(W), and tet(X)), the integrase of class 1 integrons (intI1), 16S rRNA genes, 16S rRNA genes of all Bacteroides spp., and 16S rRNA genes of human-specific Bacteroides spp. were quantified using real-time polymerase chain reaction. ARGs and intI1 quantities declined in most microcosms, with statistically significant (P < 0.05) half-lives varying between 13 d (erm(B), experiment 1, 100 g kg(-1)) and 81 d (intI1, experiment 1, 40 g kg(-1)). These kinetic rates were much slower than have been previously reported for unit operations used to treat wastewater solids (e.g., anaerobic digestion). This research suggests that the design and operation of municipal wastewater treatment facilities with the explicit goal of mitigating the release of ARGs should focus on using technologies within the treatment facility, rather than depending on attenuation subsequent to land application.