Jo Eu-Ri, Oh Jeonghyun, Cho Sung Il
Department of Otolaryngology-Head and Neck Surgery, College of Medicine, Chosun University, Gwangju 61453, Korea.
Department of Biomedical Sciences, Graduate School, Chosun University, Gwangju 61452, Korea.
Microorganisms. 2022 Sep 19;10(9):1867. doi: 10.3390/microorganisms10091867.
The formation of antibiotic-resistant strain biofilms in tympanostomy tubes results in persistent and refractory otorrhea. In the present study, we investigated the in vitro antibiofilm activity of thymol against biofilms formed by methicillin-resistant (MRSA) and ciprofloxacin-resistant (CRPA), using live and dead bacterial staining and adhesion, biofilm formation, biofilm eradication, and biofilm hydrolytic activity assays. The antibiofilm activity of thymol against tympanostomy tube biofilms formed by MRSA and CRPA strains was examined using a scanning electron microscope. In response to thymol treatment, we detected significant concentration-dependent reductions in the viability and adhesion of MRSA and CRPA. Exposure to thymol also inhibited the formation of both MRSA and CRPA biofilms. Furthermore, thymol was observed to enhance the eradication of preformed mature biofilms produced by MRSA and CRPA and also promoted a reduction in the rates of MRSA and CRPA hydrolysis. Exposure to thymol eradicated extracellular polysaccharide present in the biofilm matrix produced by MRSA and CRPA. Additionally, thymol was observed to significantly eradicate MRSA and CRPA biofilms that had formed on the surface on tympanostomy tubes. Collectively, our findings indicate that thymol is an effective inhibitor of MRSA and CRPA biofilms, and accordingly has potential utility as a therapeutic agent for the treatment of biofilm-associated refractory post-tympanostomy tube otorrhea resulting from MRSA and CRPA infection.
鼓膜置管中抗生素耐药菌株生物膜的形成会导致持续性和难治性耳漏。在本研究中,我们使用活菌和死菌染色以及黏附、生物膜形成、生物膜根除和生物膜水解活性测定法,研究了百里香酚对耐甲氧西林金黄色葡萄球菌(MRSA)和耐环丙沙星铜绿假单胞菌(CRPA)形成的生物膜的体外抗生物膜活性。使用扫描电子显微镜检查了百里香酚对由MRSA和CRPA菌株形成的鼓膜置管生物膜的抗生物膜活性。在百里香酚处理后,我们检测到MRSA和CRPA的活力和黏附力显著降低,且呈浓度依赖性。接触百里香酚也抑制了MRSA和CRPA生物膜的形成。此外,观察到百里香酚可增强对MRSA和CRPA产生的预先形成的成熟生物膜的根除作用,还能降低MRSA和CRPA的水解速率。接触百里香酚可根除MRSA和CRPA产生的生物膜基质中存在的细胞外多糖。此外,观察到百里香酚可显著根除在鼓膜置管表面形成的MRSA和CRPA生物膜。总体而言,我们的研究结果表明,百里香酚是MRSA和CRPA生物膜的有效抑制剂,因此作为治疗由MRSA和CRPA感染引起的与生物膜相关的难治性鼓膜置管后耳漏的治疗剂具有潜在用途。