Table 1_Natural compound-induced downregulation of antimicrobial resistance and biofilm-linked genes in wastewater Aeromonas species.docx

Addressing the global antimicrobial resistance (AMR) crisis requires a multifaceted innovative approach to mitigate impacts on public health, healthcare and economic systems. In the complex evolution of AMR, biofilms and the acquisition of antimicrobial resistance genes (ARGs) play a pivotal role. Aeromonas is a major AMR player that often forms biofilm, harbors ARGs and is frequently detected in wastewater. Existing wastewater treatment plants (WWTPs) do not have the capacity to totally eliminate antimicrobial-resistant bacteria favoring the evolution of ARGs in wastewater. Besides facilitating the emergence of AMR, biofilms contribute significantly to biofouling process within the activated sludge of WWTP bioreactors. This paper presents the inhibition of biofilm formation, the expression of biofilm-linked genes and ARGs by phytochemicals andrographolide, docosanol, lanosterol, quercetin, rutin and thymohydroquinone. Aeromonas species were isolated and purified from activated sludge samples. The ARGs were detected in the isolated Aeromonas species through PCR. Aeromonas biofilms were quantified following the application of biocompounds through the microtiter plate assay. qPCR analyses of related genes were done for confirmation. Findings showed that the natural compounds inhibited the formation of biofilms and reduced the expression of genes linked to biofilm production as well as ARGs in wastewater Aeromonas. This indicates the efficacy of these compounds in targeting and controlling both ARGs and biofilm formation, highlighting their potential as innovative solutions for combating antimicrobial resistance and biofouling.

应对全球抗菌药物耐药性（antimicrobial resistance, AMR）危机，需采取多维度创新策略，以减轻其对公共卫生、医疗体系及经济系统的负面影响。在抗菌药物耐药性的复杂演化过程中，生物膜（biofilms）与抗菌药物耐药基因（antimicrobial resistance genes, ARGs）的获取发挥着关键作用。气单胞菌属（Aeromonas）是引发抗菌药物耐药性的主要类群之一，其常形成生物膜、携带抗菌药物耐药基因，且频繁在污水中被检出。现有污水处理厂（wastewater treatment plants, WWTPs）无法完全清除抗菌耐药菌，这反而会促进污水中抗菌药物耐药基因的演化。除推动抗菌药物耐药性的产生外，生物膜还会显著加剧污水处理厂生物反应器活性污泥系统内的生物结垢进程。本研究探讨了六种植物化学成分——穿心莲内酯（andrographolide）、二十二烷醇（docosanol）、羊毛甾醇（lanosterol）、槲皮素（quercetin）、芦丁（rutin）与麝氢醌（thymohydroquinone）——对生物膜形成、生物膜相关基因及抗菌药物耐药基因表达的抑制作用。研究人员从活性污泥样本中分离纯化得到气单胞菌属菌株，通过聚合酶链式反应（PCR）在分离菌株中检出抗菌药物耐药基因；采用微孔板法测定施加上述生物活性化合物后气单胞菌生物膜的形成量，并通过实时定量聚合酶链式反应（qPCR）对相关基因的表达进行验证分析。研究结果显示，上述天然化合物可抑制污水中气单胞菌的生物膜形成，并下调与生物膜生成及抗菌药物耐药基因相关的基因表达水平。这证实了此类化合物可同时靶向调控生物膜形成与抗菌药物耐药基因的表达，凸显其作为应对抗菌药物耐药性及生物结垢问题的创新解决方案的应用潜力。