摘要

    猪废水（SW）是环境中抗生素抗性基因（ARG）的重要来源。但是，很少有研究评估在整个废水处理过程以及农田应用过程中ARG的发生和去除情况。这项研究调查了综合SW处理系统及其接收土壤中ARGs的概况，以及它们与SW参数和细菌群落的关系。结果显示，磺胺，四环素和氨基糖苷抗性基因在西南地区占主导地位。治疗后，SW中总ARG的相对丰度降低了84％。在西南处理单元中，厌氧消化，初级沉积和人工湿地有助于ARGs的去除，而次级沉积则增加了ARGs的总含量。处理过的西南农田的农田灌溉导致接收土壤中持久性ARG的富集，这可能归因于潜在细菌宿主的繁殖和高水平基因转移性。冗余分析表明，总ARG的相对丰度与总氮，总磷，抗生素和细菌群落显着相关。细菌群落的变化是SW治疗过程中ARGs改变的主要驱动因素。我们的结果凸显了经过处理的西南灌溉对农业环境中抗生素抗药性的影响，并有助于改善西南处理系统，以更好地控制抗生素抗性。

    Swine wastewater (SW) represents an important source of antibiotic resistance genes (ARGs) in the environment. However, few studies have assessed the occurrence and removal of ARGs in the whole wastewater treatment process followed by its farmland application. This study investigated the ARGs profiles in an integrated SW treatment system and its receiving soil, as well as their relationships with SW parameters and bacterial communities. Results revealed that sulfonamide, tetracycline and aminoglycoside resistance genes were dominant in SW. The relative abundance of total ARGs in SW was reduced by 84% after the treatments. Among the SW treatment units, anaerobic digestion, primary sedimentation and constructed wetland contributed to ARGs removal while secondary sedimentation increased the total ARGs abundance. Farmland irrigation of the treated SW resulted in enrichment of persistent ARGs in the receiving soil, which might be attributed to the propagation of potential bacterial hosts and high horizontal gene transferability. Redundancy analysis indicated that the relative abundance of total ARGs was significantly correlated with total nitrogen, total phosphorus, antibiotics and bacterial communities. The shift in bacterial community was the major driving factor for ARGs alteration during SW treatment process. Our results highlight the effect of treated SW irrigation on the antibiotic resistome in agricultural environment, and can contribute in improving SW treatment system for better antibiotic resistance control.

    https://www.sciencedirect.com/science/article/abs/pii/S0048969720311657