Krishnan Srividhya, Venkatachalam Ponnusami, Shanmugam Saravanan Ramiah, Paramasivam Nithyanand
Biofilm Biology Laboratory, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, TN, 613401, India.
Biomass, Bioenergy and Bioproducts Laboratory, School of Chemical and Biotechnology, SASTRA Deemed University, Thanjavur, TN, 613401, India.
J Med Microbiol. 2025 Mar;74(3). doi: 10.1099/jmm.0.001980.
The contact surfaces in hospitals serve as reservoirs for pathogens and account for 20-40% of hospital-acquired infections. This resistance is mainly attributed to the biofilm-forming ability of the microbes. These biofilms restrict the entry of the antibiotics to penetrate them, thus giving rise to drug resistance. Hence, there is a renewed interest in formulating an environmentally friendly, non-allergic, quick mode of action, broad-spectrum disinfectant. We hypothesize that the pure compounds present in the pyrolysis aqueous phase could act as an anti-infective and anti-biofilm agent. The present work investigates the effectiveness of furfuryl alcohol, 2-methyl-2-cyclopentenone and guaiacol as effective anti-infective agent followed by testing its biofilm eradication potential against the mixed species of multidrug-resistant pathogens such as , methicillin-resistant and . The MIC and fractional inhibitory concentrations (FIC) of the pure compounds were determined using checkerboard assay for two-compound and three-compound combinations. The biofilm eradication concentration was performed on stainless coupons, followed by RNA isolation and quantitative PCR (qPCR) analysis to elucidate virulence gene downregulation. The individual MICs of furfuryl alcohol, 2-methyl-2-cyclopentenone and guaiacol were found to be 8%, 9% and 2% (v/v), respectively. The two-compound combination FIC index of 0.75 showed partial synergy between the compounds, while the three-compound combination showed an additive effect with a FIC index of 0.87. Further, at ½ FIC (biofilm inhibitory concentration), the compounds showed 52% eradication of preformed biofilms on the hospital contact surfaces (stainless steel). The growth and time-to-kill curve showed that the compounds were not lethal to planktonic cells at BIC. Finally, the qPCR analysis showed a reduction in the expression levels of biofilm and adhesion genes, while the Quorum sensing (QS) genes were affected much more, elucidating a possible eradication mechanism. From this study, we have found a new class of compounds that have potential disinfecting ability. With the current knowledge, the future lead would be to effectively use them in disinfectant formulations.
医院中的接触表面是病原体的储存库，占医院获得性感染的20%-40%。这种耐药性主要归因于微生物形成生物膜的能力。这些生物膜限制了抗生素进入并穿透它们，从而产生耐药性。因此，人们对开发一种环境友好、无过敏反应、作用方式快速、具有广谱杀菌作用的消毒剂重新产生了兴趣。我们推测，热解水相中存在的纯化合物可作为抗感染和抗生物膜剂。本研究调查了糠醇、2-甲基-2-环戊烯酮和愈创木酚作为有效抗感染剂的有效性，随后测试了其对耐多药病原体（如耐甲氧西林金黄色葡萄球菌等）混合菌株的生物膜清除潜力。使用棋盘法测定了两种化合物和三种化合物组合的纯化合物的最低抑菌浓度（MIC）和部分抑菌浓度（FIC）。在不锈钢试片上进行生物膜清除浓度实验，随后进行RNA分离和定量PCR（qPCR）分析，以阐明毒力基因的下调情况。发现糠醇、2-甲基-2-环戊烯酮和愈创木酚的个体MIC分别为8%、9%和2%（v/v）。两种化合物组合的FIC指数为0.75，表明化合物之间存在部分协同作用，而三种化合物组合的FIC指数为0.87，显示出相加作用。此外，在1/2 FIC（生物膜抑制浓度）下，这些化合物对医院接触表面（不锈钢）上预先形成的生物膜有52%的清除率。生长和杀菌时间曲线表明，在生物膜抑制浓度下，这些化合物对浮游细胞无致死作用。最后，qPCR分析表明生物膜和黏附基因的表达水平降低，而群体感应（QS）基因受到的影响更大，阐明了一种可能的清除机制。通过这项研究，我们发现了一类具有潜在消毒能力的新化合物。根据目前的知识，未来的方向将是有效地将它们用于消毒剂配方中。
