摘要
      抗微生物耐药性（AMR）代表着一种无情的、无声的流行病。废水处理厂是造成这种情况的原因之一，它是抗生素耐药性基因（ARGs）向环境传播的潜在来源，威胁着公众健康。ARGs在致病菌中的存在及其通过污水处理厂释放到环境中威胁着公众健康。目前的研究调查了两个污水处理厂的生物营养去除（BNR）过程和厌氧消化（AD）反应器中ARGs丰度的变化。此外，还分析了已知影响ARGs分布和丰度的微生物群落结构。使用定量聚合酶链反应（qPCR）将八种ARGs（tetX、tetA、tetM、TEM、sul1、sul2、ermB和qnrD）的相对丰度定量为ARGs拷贝数/16S rRNA基因拷贝数。通过16S rRNA微生物组测序分析评估微生物群落组成。TetX在8种ARG中普遍存在，其次是TEM和sul1。然而，与BNR污泥相比，其在AD污泥中的丰度有所下降。变形杆菌是所有污泥样品中发现的主要细菌门，Arcobacter属、12up属和不动杆菌属是主要属。不动杆菌和黄杆菌在BNR污泥中明显更丰富，而12up和气单胞菌在AD污泥中占主导地位。主成分分析（PCA）显示，在两个污水处理厂的BNR和AD过程中，污泥中的主要ARG和细菌存在明显差异。在BNR和AD污泥中发现的临床相关细菌属克雷伯氏菌和肠球菌与tetX基因显著相关。在整个研究过程中，揭示了微生物群落与特定ARGs之间的关系，表明微生物群落的组成可能在ARGs的丰度中发挥至关重要的作用。这些结果将更好地为未来旨在控制ARGs及其潜在宿主从WWTP中传播的研究提供信息。
Abstract
Antimicrobial resistance (AMR) represents a relentless, silent pandemic. Contributing to this are wastewater treatment plants (WWTPs), a potential source of antibiotic resistance genes' (ARGs) transmission to the environment, threatening public health. The presence of ARGs in pathogenic bacteria and their release into the environment by WWTPs threatens the public health. The current study investigated changes in ARGs' abundance in biological nutrient removal (BNR) processes and anaerobic digestion (AD) reactors of two WWTPs. Also, microbial community structure, which is known to shape the distribution and abundance of ARGs, was also analyzed. The relative abundance of eight ARGs (tetX, tetA, tetM, TEM, sul1, sul2, ermB and qnrD) was quantified as ARGs’ copies/16 S rRNA gene copies using quantitative polymerase chain reaction (qPCR). Microbial community composition was assessed by 16 S rRNA microbiome sequencing analysis. TetX was prevalent among the eight ARGs, followed by TEM and sul1. However, its abundance was decreased in the AD sludges compared to BNR sludges. Proteobacteria was the major bacterial phylum found in all the sludge samples, while Arcobacter, 12up and Acidovorax were the predominant genera. Acinetobacter and Flavobacterium were significantly more abundant in the BNR sludges, while 12up and Aeromonas were predominant in AD sludges. Principal component analysis (PCA) revealed a clear difference in dominant ARGs and bacteria between the sludges in the processes of BNR and AD of the two WWTPs. Clinically relevant bacterial genera, Klebsiella and Enterococcus, found in both the BNR and AD sludges, were significantly correlated with the tetX gene. Throughout this study, the relationship between microbial communities and specific ARGs was revealed, illustrating that the composition of the microbial community could play a vital role in the abundance of ARGs. These results will better inform future studies aimed at controlling the spread of ARGs and their potential hosts from WWTPs.

https://www.sciencedirect.com/science/article/abs/pii/S0045653522038553