Metagenomics Shows That Low-Energy Anaerobic-Aerobic Treatment Reactors Reduce Antibiotic Resistance Gene Levels from Domestic Wastewater
Metagenomics Shows That Low-Energy Anaerobic-Aerobic Treatment Reactors Reduce Antibiotic Resistance Gene Levels from Domestic Wastewater
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DOI：
10.1021/es505521w
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发表时间：
2015-02-17
影响因子：
11.4
通讯作者：
Graham, David W.
中科院分区：
文献类型：
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作者：
Christgen, Beate;Yang, Ying;Graham, David W.
有效的生活废水处理是我们防止传染性水传播疾病传播的主要防御措施之一。然而，减少处理过程中使用的能源量对于未来已变得至关重要。一种低能量处理选择是厌氧序列（AAS）生物反应器，它使用厌氧预处理步骤（例如厌氧混合反应器）来降低碳水平，然后进行某种形式的需氧处理。尽管 AAS 在温暖气候中很常见，但尚不清楚它与其他治疗方案相比在疾病传播方面的情况如何，包括它对处理后的废水中抗生素耐药性 (AR) 的影响。在这里，我们使用宏基因组方法来对比抗生素抗性基因 (ARG) 在处理生活废水的厌氧、需氧和 AAS 生物反应器中的命运。对五个反应器配置进行了为期 6 个月的监测，并对进水和出水的处理性能、能源使用以及 ARG 丰度和多样性进行了比较。 AAS 和好氧反应器在减少 ARG 样序列丰度方面优于厌氧装置，出水 ARG 水平分别为 29、34 和 74 ppm（进水 198 ppm）。相对于厌氧单位，AAS 和需氧系统特别降低了氨基糖苷类、四环素和 β-内酰胺 ARG 水平，尽管在所有系统（评估的 234 个系统）的流出物中检测到了 63 种持久性 ARG 亚型。磺酰胺和氯霉素 ARG 水平在很大程度上不受处理的影响，而在进水和出水中，从靶标特异性 ARG 到与多药耐药性相关的 ARG 发生了广泛的转变。 AAS 反应器显示出未来应用的前景，因为它们可以用更少的能量减少更多的 ARG（此处能量减少 32%），但所有三种处理方案都有局限性，需要进一步研究。
Effective domestic wastewater treatment is among our primary defenses against the dissemination of infectious waterborne disease. However, reducing the amount of energy used in treatment processes has become essential for the future. One low-energy treatment option is anaerobicaerobic sequence (AAS) bioreactors, which use an anaerobic pretreatment step (e.g., anaerobic hybrid reactors) to reduce carbon levels, followed by some form of aerobic treatment. Although AAS is common in warm climates, it is not known how its compares to other treatment options relative to disease transmission, including its influence on antibiotic resistance (AR) in treated effluents. Here, we used metagenomic approaches to contrast the fate of antibiotic-resistant genes (ARG) in anaerobic, aerobic, and AAS bioreactors treating domestic wastewater. Five reactor configurations were monitored for 6 months, and treatment performance, energy use, and ARG abundance and diversity were compared in influents and effluents. AAS and aerobic reactors were superior to anaerobic units in reducing ARG-like sequence abundances, with effluent ARG levels of 29, 34, and 74 ppm (198 ppm influent), respectively. AAS and aerobic systems especially reduced aminoglycoside, tetracycline, and beta-lactam ARG levels relative to anaerobic units, although 63 persistent ARG subtypes were detected in effluents from all systems (of 234 assessed). Sulfonamide and chloramphenicol ARG levels were largely unaffected by treatment, whereas a broad shift from target-specific ARGs to ARGs associated with multi-drug resistance was seen across influents and effluents. AAS reactors show promise for future applications because they can reduce more ARGs for less energy (32% less energy here), but all three treatment options have limitations and need further study.