摘要

生活污水处理厂作为抗生素抗性基因( ARGs )的储存库，已受到广泛关注，但染料对ARGs传播的影响却鲜有研究。采用高通量qPCR和16S rRNA基因测序技术，研究了混合（染色和家庭）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 )的ARGs相对丰度高于生活废水( IW1 )。纺织印染废水( IDW3 )流入量中可移动遗传因子的相对丰度是其它样品的3～13倍。此外，在IDW3中，一些明显的高丰度ARGs，特别是编码外排泵的操纵子(如acrR - 01、acrB - 01和acrF )与厚壁菌属的链球菌显著相关。为探讨混合废水中ARGs含量较高的原因，采用6种具有代表性的纺织印染废水有机化合物，研究了质粒介导的大肠杆菌HB101与NK5449的偶联转移效应。这六种化合物均有利于携带抗性的RP4质粒的转移，最高转移频率(约10-5 - 10-3 )比对照组(约10-6 - 10-5 )高出4 - 200倍。这些结果表明，六种常见的残留化合物，特别是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，本研究首次揭示了染色污染物对ARGs水平基因转移( HGT )的影响。

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/pii/S0045653517308639