摘要

废水处理厂的废水被认为是抗生素和抗生素抗性基因( ARGs)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缺水问题，但RWI对ARGs模式和土壤细菌群落的影响尚不清楚。本文采用高通量定量PCR和末端限制性片段长度多态性技术，比较了澳大利亚维多利亚12个城市公园(含和不含RWI)中ARGs和总细菌的多样性、丰度和组成。在所有公园土壤中共检测到40种独特的ARG，其中β-内酰胺抗性基因是最普遍的ARG类型。RWI显著增加了ARG的总量和本书变化，并且在城市公园中，RWI与未RWI相比ARG模式也发生了显著变化。ARG模式的变化与RWI对细菌群落结构的显著影响和所检测ARG类型的共现模式平行。整合酶inti 1基因与两个β-内酰胺抗性基因( KPC和IMP - 2组)的倍数变化呈显著正相关，但RWI对inti1和转座酶tnpA基因的丰度没有显著影响，说明RWI并未提高土壤ARGs水平基因潜在迁移性。综上所述，我们的研究结果表明，再生水灌溉城市公园可以影响各种临床相关性土壤ARGs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.

http://www.sciencedirect.com/science/article/pii/S0269749115302475