摘要

  抗生素抗性基因 (ARG) 是新出现的污染物，对全球人类健康构成潜在威胁。城市污水处理厂 (WWTP) 是释放到环境中的耐抗生素细菌和 ARG 的主要来源。然而，韩国很少研究 ARGs 的传播及其潜在机制以及污水处理厂中移动遗传元件 (MGEs) 的动态。在这项研究中，使用鸟枪宏基因组分析从 2 个活性污泥 (AS) 和 2 个厌氧消化污泥 (ADS) 样本的 4 种配置中识别综合 ARG 及其机制、细菌群落和 MGE。共检测到属于 22 个 ARG 类型的 181 个 ARG 亚型，AS 样品中的 ARG 丰度比 ADS 样品高 1.3-2.0 个数量级。多药和杆菌肽抗性基因是 AS 样品中的主要 ARG 类型，其次是针对磺胺、四环素和 β-内酰胺的 ARG。然而，ADS 样品中 ARG 类型的组成发生了显着变化。 ADS 样品中多药和 β-内酰胺抗性基因的丰度显着降低。在 ADS 样品中，MLS 的抗性基因占主导地位，其次是 ARGs 对磺胺和四环素的耐药基因。此外，质粒是 AS 样品中的主要 MGE，而整合子 (intI1) 是 ADS 样品中的主要 MGE。这些结果提供了关于 ARG 类型和 MGE 的流行以及 AS 和 ADS 系统之间的差异模式的有价值的信息。

  Antibiotic resistance genes (ARGs) are emerging contaminants that pose a potential threat to human health worldwide. Urban wastewater treatment plants (WWTPs) are a main source of both antibiotic-resistant bacteria and ARGs released into the environment. Nevertheless, the propagation of ARGs and their underlying mechanisms and the dynamics of mobile genetic elements (MGEs) in WWTPs have rarely been investigated in South Korea. In this study, shotgun metagenomic analysis was used to identify comprehensive ARGs and their mechanisms, bacterial communities, and MGEs from 4 configurations with 2 activated sludge (AS) and 2 anaerobic digestion sludge (ADS) samples. A total of 181 ARG subtypes belonging to 22 ARG types were broadly detected, and the ARG abundances in the AS samples were 1.3–2.0 orders of magnitude higher than in the ADS samples. Multidrug and bacitracin resistance genes were the predominant ARG types in AS samples, followed by ARGs against sulfonamide, tetracycline, and β-lactam. However, the composition of ARG types in ADS samples was significantly changed. The abundance of multidrug and β-lactam resistance genes was drastically reduced in the ADS samples. The resistance genes of MLS were the predominant, followed by ARGs against sulfonamide and tetracycline in the ADS samples. In addition, plasmids were the dominant MGEs in the AS samples, while integrons (intI1) were the dominant MGEs in the ADS samples. These results provide valuable information regarding the prevalence of ARG types and MGEs and the difference patterns between the AS and ADS systems.

  https://link.springer.com/article/10.1007/s12275-020-9309-y