摘要

       抗生素广泛用于牲畜，用于治疗感染和促进生长。畜牧业废物是抗生素不敏感病原体的潜在环境来源，目前污水处理厂 (WWTP) 中耐药基因型的去除效率尚不清楚。在本研究中，定量 PCR 用于评估废水处理过程中的抗生素抗性基因。本研究包括不同养猪场的六个污水处理厂，每个处理程序测试了五个抗生素抗性基因（ARG）。所有测试的ARGs，包括tetA、tetW、sulI、sulII和blaTEM基因，在6个养猪场中均被检测到，数量相当可观。结果表明，抗生素耐药性在畜牧业中普遍存在。 ARG 水平因废水处理程序而异，通常在厌氧处理池中最高，而在活性污泥单元和出水处最低。将 ARG 水平标准化为 16S rRNA 基因拷贝后，结果显示污水处理厂单位中的 ARG 部分随细菌数量波动。不管其在生物降解中的重要性，厌氧过程可能会促进细菌生长，从而增加抗生素抗性基因型的可持续性。在比较流入和流出样品中的拷贝数后，ARG 的平均去除效率介于 33.30 和 97.56% 之间。结果表明，污水处理厂的处理可以部分减少抗生素抗性细菌的传播，沉淀等额外程序可能不会严重影响去除效率。

       Antibiotics are widely used in livestock for infection treatment and growth promotion. Wastes from animal husbandry are a potential environmental source of antibiotic-insensitive pathogens, and the removal efficiency of the resistance genotypes in current wastewater treatment plants (WWTPs) is unknown. In this study, quantitative PCR was used for evaluating antibiotic resistance genes in wastewater treatment processes. Six wastewater treatment plants in different swine farms were included in this study, and five antibiotic resistance genes (ARGs) were tested for each treatment procedure. All of the tested ARGs including tetA, tetW, sulI, sulII, and blaTEM genes were detected in six swine farms with considerable amounts. The results showed that antibiotic resistance is prevalent in livestock farming. The ARG levels were varied by wastewater treatment procedure, frequently with the highest level at anaerobic treatment tank and lowest in the activated sludge unit and the effluents. After normalizing the ARG levels to 16S rRNA gene copies, the results showed that ARGs in WWTP units fluctuated partly with the quantity of bacteria. Regardless of its importance in biodegradation, the anaerobic procedure may facilitate bacterial growth thus increasing the sustainability of the antibiotic resistance genotypes. After comparing the copy numbers in influx and efflux samples, the mean removal efficiency of ARGs ranged between 33.30 and 97.56%. The results suggested that treatments in the WWTP could partially reduce the spread of antibiotic-resistant bacteria, and additional procedures such as sedimentation may not critically affect the removal efficiency.
https://www.sciencedirect.com/science/article/abs/pii/S0048969714010390