摘要

       生活污水处理厂作为抗生素抗性基因 (ARGs) 的储存库受到了很多关注，但很少研究染料对 ARGs 繁殖的影响。在这项研究中，我们分别使用高通量 qPCR 和 16S rRNA 基因测序研究了混合（染色和生活）废水和生活污水之间 ARG 和微生物群落的分布差异。混合废水（IW2 和 IW3）流入中 ARG 的相对丰度高于生活废水（IW1）。流入的纺织印染废水（IDW3）中移动遗传元件的相对丰度比其他样品高 3 至 13 倍。此外，在 IDW3 中，一些独特的高丰度 ARG，特别是编码外排泵的操纵子（如 acrR-01、acrB-01 和 acrF），与厚壁菌门的链球菌显着相关。为了探究混合废水中 ARG 丰度相对较高的原因，我们使用纺织印染废水中六种代表性有机化合物来测试对基于质粒的共轭转移从大肠杆菌 HB101 到大肠杆菌 NK5449 的影响。这6种化合物均促进了携带抗性RP4质粒的转移，最高转移频率（约10-5-10-3）比对照组高4-200倍（约10-6- 10-5）。这些结果表明，六种常见的残留化合物，尤其是 IDW3 中的低剂量物质，可以促进 ARGs 在水生环境中的传播。更重要的是，这项研究首次揭示了染色污染物影响 ARG 的水平基因转移 (HGT)。

       Domestic wastewater treatment plants as a reservoir of antibiotic resistance genes (ARGs) have received much attention, but the effect of dyes on the propagation of ARGs has rarely been investigated. In this study, we investigated the differences in distributions of ARGs and microbial communities using high-throughput qPCR and 16S rRNA gene sequencing, respectively, between mixed (dyeing and domestic) wastewater and domestic sewage. The relative abundance of ARGs in inflows of mixed wastewater (IW2 and IW3) was higher than that of domestic wastewater (IW1). The relative abundance of mobile genetic elements in the inflow of textile dyeing wastewater (IDW3) was 3- to 13-fold higher than that in other samples. Moreover, in IDW3, some distinct high abundance ARGs, particularly operons encoding efflux pumps (such as acrR-01, acrB-01 and acrF), were significantly correlated with Streptococcus of the Firmicutes. To explore why the abundance of ARGs was relatively high in mixed wastewater, six representative types of organic compounds in textile dyeing wastewater were used to test the effect on plasmid-based conjugative transfer from E. coli HB101 to E. coli NK5449. These six compounds all facilitated the transfer of resistance-carrying RP4 plasmid, and the highest transfer frequency (approximately 10−5-10−3) was over 4- to 200-fold higher than that in the control group (approximately 10−6-10−5). These results illustrated that the six common residual compounds, particularly low-dose substances in IDW3, could facilitate the dissemination of ARGs in aquatic environments. More importantly, this study revealed for the first time that dyeing contaminants influenced horizontal gene transfer (HGT) of ARGs.

https://www.sciencedirect.com/science/article/abs/pii/S0045653517308639