Microplastics as hubs enriching antibiotic-resistant bacteria and pathogens in municipal activated sludge
Microplastics as hubs enriching antibiotic-resistant bacteria and pathogens in municipal activated sludge
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DOI：
10.1016/j.hazl.2021.100014
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Dung Ngoc Pham;Lerone Clark;Mengyan Li
中科院分区：
文献类型：
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作者：
Dung Ngoc Pham;Lerone Clark;Mengyan Li
微塑料可以作为耐药细菌（ARB）和病原体的载体，对水生生物群和人类健康构成了紧迫的问题。城市污水处理厂（WWTPs）的活性污泥单元是聚合微塑料和抗生素的“热点”。在这批研究中，从国内三个污水处理厂的活性污泥样品，我们证明了聚乙烯（PE）和聚苯乙烯（PS）微塑料可以驯化生物膜富集磺胺抗性基因（sul 1和sul 2）和相关的移动的遗传元件（intI 1）相比，细砂作为对照颗粒。当磺胺甲恶唑最初作为代表性磺胺添加时，这些基因的绝对丰度进一步升高1.2 - 4.5倍。16 S rRNA扩增子测序和差异排序分析的组合揭示了微塑料选择性地促进了抗虫性和致病性分类群（例如，Raoultella ornithinolyticaandStenotrophomonas maltophilia），富集指数为1.6 ~ 3.3。微塑料生物膜中异养新鞘氨醇菌和异养鞭毛杆菌的平均含量分别为14.6%和3.3%，分别是砂生物膜的2.8倍和11.1倍.这些细菌物种的优势可能有助于初始生物膜的形成，促进ARB和病原体的后续定植和增殖，从而放大其在接收环境内外的风险。
Microplastics can serve as carriers of antibiotic-resistant bacteria (ARB) and pathogens, representing a pressing concern to aquatic biota and human health. Activated sludge units at municipal wastewater treatment plants (WWTPs) are “hotspots” converging microplastics and antibiotics. In this batch study with activated sludge samples from three domestic WWTPs, we demonstrated both polyethylene (PE) and polystyrene (PS) microplastics can acclimate biofilms enriched with sulfonamide resistance genes (sul1andsul2) and the associated mobile genetic element (intI1) in comparison with fine sands as control particles. Absolute abundances of these genes were further elevated by 1.2∼4.5 fold when sulfamethoxazole was initially spiked as a representative sulfonamide. The combination of 16S rRNA amplicon sequencing and differential ranking analysis revealed that microplastics selectively promoted antibiotic-resistant and pathogenic taxa (e.g.,Raoultella ornithinolyticaandStenotrophomonas maltophilia) with enrichment indices ranging from 1.6 to 3.3. Furthermore, heterotrophicNovosphingobiumand filamentousFlectobacillusaccounted for 14.6 % and 3.3 % on average in microplastic biofilms, respectively, which were up to 2.8 and 11.1 times higher than those in sand biofilms. Dominance of these bacterial species may contribute to initial biofilm formation that facilitates subsequent colonization and proliferation of ARB and pathogens, thus amplifying their risks in the receiving environments and beyond.