State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
Environ Pollut. 2021 Nov 1;288:117736. doi: 10.1016/j.envpol.2021.117736. Epub 2021 Jul 7.
Overuse of antibiotics is accelerating the spread of resistance risk in the environment. In drinking water supply systems, the effect of antibiotics on the resistance of biofilm is unclear, and there have been few studies in disinfectant-containing systems. Here, we designed a series of drinking water supply reactors to investigate the effects of antibiotics on biofilm and bacteria in the water. At low concentrations, antibiotics could promote the growth of bacteria in biofilm; among the tested antibiotics (tetracycline, sulfadiazine and chloramphenicol), tetracycline had the strongest ability to promote this. And the antibiotic resistant bacteria (ARB) could inhibit the growth of bacteria in drinking water. Results have shown that antibiotics enhanced the bacterial chlorine resistance in the effluent, but reduced that in the biofilm. Furthermore, metagenomic analysis showed that antibiotics reduced the richness of biofilm communities. The dominant phyla in the biofilm were Proteobacteria, Planctomycetes, and Firmicutes. In tetracycline-treated biofilm, the dominant phylum was Planctomycetes. In sulfadiazine- and chloramphenicol-treated groups, bacteria with complex cell structures preferentially accumulated. The dominant class in biofilm in the ARB-added group was Gammaproteobacteria. The abundance of antibiotic resistant genes (ARGs) was correlated with biofilm community structure. This study shows that antibiotics make the biofilm community structure of drinking water more resistant to chlorine. ARGs may be selective for certain bacteria in the process, and there may ultimately be enhanced chlorine and antibiotic resistance of effluent bacteria in drinking water.
抗生素的过度使用正在加速环境中耐药风险的传播。在饮用水供应系统中，抗生素对生物膜耐药性的影响尚不清楚，且在含消毒剂的系统中研究较少。在这里，我们设计了一系列饮用水供应反应器，以研究抗生素对水中生物膜和细菌的影响。在低浓度下，抗生素可以促进生物膜中细菌的生长；在所测试的抗生素（四环素、磺胺嘧啶和氯霉素）中，四环素具有最强的促进作用。并且抗生素耐药菌（ARB）可以抑制饮用水中细菌的生长。结果表明，抗生素增强了出水中细菌的氯抗性，但降低了生物膜中的氯抗性。此外，宏基因组分析表明，抗生素降低了生物膜群落的丰富度。生物膜中的优势门为变形菌门、浮霉菌门和厚壁菌门。在四环素处理的生物膜中，优势门为浮霉菌门。在磺胺嘧啶和氯霉素处理组中，具有复杂细胞结构的细菌优先积累。在添加 ARB 的组中，生物膜中的优势纲为γ变形菌纲。抗生素耐药基因（ARGs）的丰度与生物膜群落结构相关。本研究表明，抗生素使饮用水的生物膜群落结构更能抵抗氯。ARGs 可能在该过程中对某些细菌具有选择性，最终可能导致饮用水中出水中的细菌对氯和抗生素的抗性增强。
