摘要

       目前，高抗生素浓度对活性污泥 (AS) 过程中微生物群和抗生素抗性基因 (ARG) 的影响尚未得到很好的表征。使用基于高通量测序的 16S rRNA 基因和宏基因组分析，使用实验室规模的批量反应器来评估微生物群落和 ARGs 对不同浓度的六种抗生素的反应动态。抗生素的存在显着降低了微生物的多样性，引起了微生物群结构的巨大变化，并对潜在的抗生素抗性细菌（ARB）的富集施加了选择压力，如节杆菌、Thauera、Geothrix、Rudaea、Aridibacter、Conexibacter、 Terrimonas 等。高抗生素选择压力增加了 ARG 丰度，但同时减少了 ARG 数量。总共检测到属于 20 个 ARG 类型的 491 个 ARG 亚型，卡那霉素处理显示出最高的 ARG 丰度。所有样品共享一组核心的 54 个 ARG 亚型，占总 ARG 丰度的 66.7%–99.6%。在特定抗生素治疗下相应和非相应 ARG 丰度的增加揭示了抗生素选择压力的附带影响。微生物群落可能在 ARG 的组成中起重要作用。网络分析表明，内部型和外部型 ARGs 均表现出较高的非随机共现发生率，推测 18 个属为多个 ARGs 的可能宿主。本研究揭示了 AS 工艺处理高抗生素浓度废水中微生物群落与 ARGs 之间的概况和关系，可为控制 ARB 和 ARGs 的发展和传播提供有用的指导。

       Currently, the effects of high antibiotic concentrations on the performance of microbiota and antibiotic resistance genes (ARGs) in activated sludge (AS) process are not well characterized. Lab-scale batch reactors were performed to evaluate the dynamics of microbial community and ARGs in response to six antibiotics at different concentrations using high-throughput sequencing-based 16S rRNA gene and metagenomic analyses. The presence of antibiotics remarkably decreased the microbial diversity, caused a great change of the microbiota structure, and exerted a selective pressure on the enrichment of potential antibiotic resistant bacteria (ARB), such as Arthrobacter, Thauera, Geothrix, Rudaea, Aridibacter, Conexibacter, Terrimonas, etc. High antibiotic selective pressures increased ARG abundance but simultaneously reduced ARG number. In total, 491 ARG subtypes belonging to 20 ARG types were detected and kanamycin treatment showed the highest ARG abundances. A core set of 54 ARG subtypes that accounted for 66.7%–99.6% of the total ARG abundances were shared by all samples. The increase of the abundances of both corresponding and non-corresponding ARGs under a specific antibiotic treatment revealed the collateral effects of antibiotic selective pressure. Microbial community may play an important role in the composition of ARGs. Network analysis indicated that both internal-type and external-type of ARGs exhibited higher non-random co-occurrence incidences and 18 genera were speculated as the possible hosts for multiple ARGs. This study deciphered the profiles and relationships between microbial community and ARGs in AS process treating wastewater with high antibiotic concentrations and could provide helpful guidance for controlling the development and dissemination of ARB and ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0043135418310522