Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences, Xinxiang 453002, China.
Department of Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Devon EX22 2SB, UK.
J Hazard Mater. 2022 Mar 5;425:128046. doi: 10.1016/j.jhazmat.2021.128046. Epub 2021 Dec 10.
The effects of reclaimed wastewater (RW) irrigation on the spread of antibiotic resistance genes (ARGs) in soil is modulated by a myriad of biotic and abiotic factors and their relative significance remains vague. We compared microbial communities, assemblages of genes associated with microbial resistance to antibiotics, biocides and metals, and insertion sequences (ISs) in soils following 16 years of irrigation with groundwater (GW), RW or alternately with GW and RW in two greenhouses with different cropping systems, using shotgun metagenome sequencing. The results showed that cropping system exerted greater influence than irrigation on the profile of ISs and resistance genes. This influence was most strongly associated with concentrations of copper, mercury and perfloxacin in the soils. There was no significant difference in soil ARG profiles between continuous RW irrigation and alternating GW and RW irrigation. Proteobacteria, Actinobacteria and Firmicutes and a limited number of ISs were closely associated with the detected ARGs. Most ARGs were found to co-occur with metal and biocide resistance genes through the mechanism of efflux pumps. These findings highlight the significance of understanding and improving crop management in mitigating the dissemination of ARGs in soils irrigated with RW.
再生水灌溉对土壤中抗生素抗性基因（ARGs）传播的影响受到多种生物和非生物因素的调节，其相对重要性尚不清楚。我们比较了在两个温室中经过 16 年地下水（GW）、再生水（RW）或 GW 和 RW 交替灌溉后土壤中的微生物群落、与抗生素、杀生物剂和金属抗性相关的基因组合以及插入序列（ISs），使用了 shotgun 宏基因组测序。结果表明，种植系统对 ISs 和抗性基因的分布比灌溉的影响更大。这种影响与土壤中铜、汞和培氟沙星的浓度密切相关。连续 RW 灌溉和 GW 和 RW 交替灌溉之间的土壤 ARG 分布没有显著差异。变形菌门、放线菌门和厚壁菌门以及少数几种 ISs 与检测到的 ARGs 密切相关。大多数 ARGs 被发现通过外排泵机制与金属和杀生物剂抗性基因共同存在。这些发现强调了理解和改善作物管理以减轻 RW 灌溉土壤中 ARGs 传播的重要性。
