Combatting antibiotic resistance is critical to our ability to treat infectious diseases. Here, we identified and characterized diverse antimicrobial resistance genes, including potentially mobile elements, from synthetic wastewater treatment microcosms exposed to the antibacterial agent triclosan. After seven weeks of exposure, the microcosms were subjected to functional metagenomic selection across 13 antimicrobials. This was achieved by cloning the combined genetic material from the microcosms, introducing this genetic library into E. coli, and selecting for clones that grew on media supplemented with one of the 13 antimicrobials. We recovered resistant clones capable of growth on media supplemented with a single antimicrobial, yielding 13 clones conferring resistance to at least one antimicrobial agent. Antibiotic susceptibility analysis revealed resistance ranging from 4 to >50 fold more resistant, while one clone showed resistance to multiple antibiotics. Using both Sanger and SMRT sequencing, we identified the predicted active gene(s) on each clone. One clone that conferred resistance to tetracycline contained a gene encoding a novel tetA-type efflux pump that was named TetA(62). Three clones contained predicted active genes on class 1 integrons. One integron had a previously unreported genetic arrangement and was named In1875. This study demonstrated the diversity and potential for spread of resistance genes present in human-impacted environments.

对抗抗生素耐药性对于我们治疗传染病的能力至关重要。在这里，我们从暴露于抗菌剂三氯生的合成废水处理微观世界中鉴定并表征了多种抗菌素抗性基因，包括潜在的移动元素。暴露七周后，微观世界接受了 13 种抗菌药物的功能宏基因组选择。这是通过克隆来自微观世界的组合遗传物质，将该遗传文库引入大肠杆菌来实现的，并选择在补充有 13 种抗菌剂之一的培养基上生长的克隆。我们回收了能够在补充有单一抗菌剂的培养基上生长的抗性克隆，产生了 13 个对至少一种抗菌剂具有抗性的克隆。抗生素敏感性分析显示耐药性范围从 4 倍到 >50 倍不等，而一个克隆显示对多种抗生素的耐药性。使用 Sanger 和 SMRT 测序，我们确定了每个克隆上的预测活性基因。一个赋予四环素抗性的克隆含有编码一种名为 TetA(62) 的新型 tetA 型外排泵的基因。三个克隆在 1 类整合子上含有预测的活性基因。一个整合子具有以前未报告的遗传排列，并被命名为 In1875。