Pandit Santosh, Kim Mi-A, Jung Ji-Eun, Choi Hyeon-Mi, Jeon Jae-Gyu
Systems and Synthetic Biology Division, Department of Life Sciences, Chalmers University of Technology, SE-412 96, Gothenburg, Sweden.
Department of Preventive Dentistry, School of Dentistry, Jeonbuk National University, Jeonju, Republic of Korea.
Biofilm. 2024 Nov 30;8:100241. doi: 10.1016/j.bioflm.2024.100241. eCollection 2024 Dec.
Bacterial biofilms are highly structured surface associated architecture of micro-colonies, which are strongly bonded with the exopolymeric matrix of their own synthesis. These exopolymeric substances, mainly exopolysaccharides (EPS) initially assist the bacterial adhesion and finally form a bridge over the microcolonies to protect them from environmental assaults and antimicrobial exposure. Bacterial cells in dental biofilm metabolize dietary carbohydrates and produce organic acids. The blanket of exopolysaccharides over the bacterial communities hinders the buffering by saliva, contributing to the initiation of tooth decay followed by the progression of dental caries. Considering the current interest towards the use of natural antimicrobial agents to disarm the cariogenic properties of dental biofilm, this study evaluated the antimicrobial activity and the effect of twice daily brief exposure (1 min) of usnic acid on acid production, acid tolerance and development of 3-dimensional architecture of biofilm. Herein, biofilms were briefly treated twice daily during biofilm development and biofilms were analyzed by using biochemical, microbiological and microscopic examination. Results obtained in this study showed a significant reduction in virulence properties of biofilm cells treated with usnic acid in compared to non-treated biofilms. Furthermore, twice daily brief exposure of usnic acid significantly disrupted the acid production and reduced the complexity of biofilm by disrupting the EPS production. Brief exposure of usnic acid inhibited the production of glucosyltransferase (GTF) enzymes and their enzymatic activity leading to inhibition in production of EPS on the biofilm matrix. In conclusion, usnic acid treatment reduced the cariogenic properties and complexity of biofilm by inhibiting acid production, acid tolerance and disrupting extracellular polysaccharide (EPS) formation, indicating its potential for preventing dental caries.
细菌生物膜是高度结构化的与表面相关的微菌落结构，这些微菌落与它们自身合成的胞外聚合物基质紧密结合。这些胞外聚合物物质，主要是胞外多糖（EPS），最初有助于细菌黏附，最终在微菌落上形成桥梁，以保护它们免受环境攻击和抗菌剂暴露。牙菌斑中的细菌细胞代谢膳食碳水化合物并产生有机酸。细菌群落上的胞外多糖层阻碍了唾液的缓冲作用，导致龋齿的发生，随后龋齿进一步发展。考虑到当前对使用天然抗菌剂来消除牙菌斑致龋特性的兴趣，本研究评估了松萝酸每日两次短暂暴露（1分钟）对生物膜产酸、耐酸性和三维结构发育的抗菌活性及影响。在此，在生物膜形成过程中，每天对生物膜进行两次短暂处理，并通过生化、微生物学和显微镜检查对生物膜进行分析。本研究获得的结果表明，与未处理的生物膜相比，用松萝酸处理的生物膜细胞的毒力特性显著降低。此外，松萝酸每日两次短暂暴露显著破坏了产酸过程，并通过破坏EPS的产生降低了生物膜的复杂性。松萝酸的短暂暴露抑制了葡糖基转移酶（GTF）的产生及其酶活性，导致生物膜基质上EPS的产生受到抑制。总之，松萝酸处理通过抑制产酸、耐酸性和破坏细胞外多糖（EPS）的形成，降低了生物膜的致龋特性和复杂性，表明其在预防龋齿方面的潜力。
