摘要

       废水处理厂的流出物已被认为是抗生素和抗生素抗性基因 (ARG) 的重要环境库。再生水灌溉（RWI）越来越多地被用作解决干旱和半干旱地区水资源短缺的实用解决方案，然而，再生水灌溉对 ARGs 模式和土壤细菌群落的影响仍不清楚。在这里，我们使用高通量定量 PCR 和末端限制性片段长度多态性技术来比较澳大利亚维多利亚州有和没有 RWI 的 12 个城市公园中广谱 ARG 和总细菌的多样性、丰度和组成。在所有公园土壤中总共检测到 40 种独特的 ARG，其中对 β-内酰胺具有抗性的基因是最普遍的 ARG 类型。 RWI显着增加了检测到的ARG的总数和倍数变化，并且与没有RWI的城市公园相比，在有RWI的城市公园中也观察到了ARG模式的显着变化。 ARG 模式的变化与 RWI 对细菌群落结构的显着影响和检测到的 ARG 类型的共现模式平行。整合酶intI1基因与两个β-内酰胺抗性基因（KPC和IMP-2组）的倍数变化呈显着正相关，但未发现RWI对intI1和转座酶tnpA基因丰度的影响，表明 RWI 没有提高土壤 ARG 水平基因转移的潜力。综上所述，我们的研究结果表明，用再生水灌溉城市公园可能会影响各种具有临床相关性的土壤 ARG 的丰度、多样性和组成。

       The effluents from wastewater treatment plants have been recognized as a significant environmental reservoir of antibiotics and antibiotic resistance genes (ARGs). Reclaimed water irrigation (RWI) is increasingly used as a practical solution for combating water scarcity in arid and semiarid regions, however, impacts of RWI on the patterns of ARGs and the soil bacterial community remain unclear. Here, we used high-throughput quantitative PCR and terminal restriction fragment length polymorphism techniques to compare the diversity, abundance and composition of a broad-spectrum of ARGs and total bacteria in 12 urban parks with and without RWI in Victoria, Australia. A total of 40 unique ARGs were detected across all park soils, with genes conferring resistance to β-lactam being the most prevalent ARG type. The total numbers and the fold changes of the detected ARGs were significantly increased by RWI, and marked shifts in ARG patterns were also observed in urban parks with RWI compared to those without RWI. The changes in ARG patterns were paralleled by a significant effect of RWI on the bacterial community structure and a co-occurrence pattern of the detected ARG types. There were significant and positive correlations between the fold changes of the integrase intI1 gene and two β-lactam resistance genes (KPC and IMP-2 groups), but no significant impacts of RWI on the abundances of intI1 and the transposase tnpA gene were found, indicating that RWI did not improve the potential for horizontal gene transfer of soil ARGs. Taken together, our findings suggested that irrigation of urban parks with reclaimed water could influence the abundance, diversity, and compositions of a wide variety of soil ARGs of clinical relevance.

https://www.sciencedirect.com/science/article/abs/pii/S0269749115302475