摘要
      废活性污泥（WAS）中对氯间二甲酚（PCMX，作为大量消耗的抗菌化学品）的出现将对WAS的利用构成环境风险。本研究表明，PCMX主要促进了抗生素抗性基因（ARGs）的丰富性和多样性，特别是多药基因（即acrB和mexW），并重塑了WAS发酵过程中的抗性机制类别。基因型和表型结果表明，PCMX通过破坏WAS结构上调转座酶的丰度并增加细胞通透性，这进一步促进了ARGs的水平转移。ARGs、可移动遗传元件（MGE）和属（即鞘氨醇菌属和伪黄单胞菌属）之间的网络和相关性分析证实，PCMX富集了与多药耐药机制相关的潜在ARGs宿主。此外，PCMX上调了参与ARGs相关代谢途径的基因，如双组分（即phoP和vcaM）和群体感应系统（即lasR和cciR），它们通过多药外排泵和外膜蛋白决定ARGs的增殖，并促进了ARGs宿主之间的识别。方差划分分析（VPA）表明，微生物群落的变化主要是ARGs传播的原因。这些发现以深刻的理解揭示了WAS中外源污染物的环境行为和风险，可以指导WAS的资源回收利用。
Abstract
The occurrence of para-chloro-meta-xylenol (PCMX, as largely consumed antimicrobial chemicals) in waste activated sludge (WAS) would pose environmental risks for WAS utilization. This study revealed that PCMX principally prompted the abundances and diversity of antibiotic resistance genes (ARGs), particularly for the multidrug- genes (i.e., acrB and mexW), and reshaped the resistance mechanism categories during WAS fermentation process. The genotype and phenotype results indicated that PCMX upregulated abundances of transposase and increased cell permeability via disrupting WAS structure, which further facilitated the horizontal transfer of ARGs. The network and correlation analysis among ARGs, mobile genetic elements (MGEs) and genera (i.e., Sphingopyxis and Pseudoxanthomonas) verified that PCMX enriched the potential ARGs hosts associated with multidrug resistance mechanism. Also, PCMX upregulated the genes involved in ARGs-associated metabolic pathways, such as two-component (i.e., phoP and vcaM) and quorum sensing systems (i.e., lasR and cciR), which determined the ARGs proliferation via multidrug efflux pump and outer membrane proteins, and facilitated the recognition between ARGs hosts. Variance partitioning analysis (VPA) implied that the shift of microbial community contributed predominantly to the dissemination of ARGs. These findings unveiled the environmental behaviors and risks of exogenous pollutants in WAS with insightful understanding, which could guide the WAS utilization for resource recovery.

https://www.sciencedirect.com/science/article/abs/pii/S0048969722051828