Ko Yoo-Seung, Gi Eun-Ji, Lee Sungsu, Kim Hong-Chan, Cho Hyong-Ho
Department of Otolaryngology-Head and Neck Surgery, Chonnam National University Medical School and Chonnam National University Hospital, 42 Jaebong-Ro, Dong-Gu, Gwangju, 61469, Republic of Korea.
Biofilm. 2025 Aug 21;10:100314. doi: 10.1016/j.bioflm.2025.100314. eCollection 2025 Dec.
Otitis media (OM), particularly when caused by methicillin-resistant (MRSA), can become refractory due to biofilm formation, which contributes to resistance against conventional antimicrobial treatments. Photobiomodulation using light-emitting diode (LED) therapy has recently emerged as a promising non-antibiotic strategy for managing refractory infections by targeting biofilm-associated pathology. However, especially in the context of MRSA-induced OM, its therapeutic efficacy and underlying mechanisms remain incompletely elucidated. In this study, we established a rat model of OM by inoculating MRSA (5 × 10 CFUs) into the middle ear via the tympanic membrane. Red and near-infrared (NIR) LED irradiation (655/842 nm; 163.2 W/m; 30 min/day for 5 days) was administered 1 week after infection. Scanning electron microscopy revealed a marked reduction in MRSA biofilm structures, and biofilm biomass was significantly decreased, as assessed by crystal violet staining. Quantitative real-time polymerase chain reaction (qRT-PCR) analysis demonstrated significant downregulation of , , , and , key genes crucial for bacterial adhesion and biofilm development. Histological assessment further showed decreased mucosal thickening and macrophage infiltration, supported by reduced ionized calcium-binding adapter molecule 1 (Iba1) expression. These findings suggest that dual red and NIR LED therapy effectively suppresses MRSA biofilm formation and inflammation in OM, indicating its potential as a novel non-antibiotic therapy for biofilm-associated OM that may help manage persistent or treatment-resistant cases in clinical settings.
中耳炎（OM），尤其是由耐甲氧西林金黄色葡萄球菌（MRSA）引起的中耳炎，可能会因生物膜形成而变得难治，生物膜会导致对传统抗菌治疗产生耐药性。使用发光二极管（LED）疗法的光生物调节最近已成为一种有前景的非抗生素策略，通过针对生物膜相关病理来管理难治性感染。然而，特别是在MRSA引起的中耳炎的背景下，其治疗效果和潜在机制仍未完全阐明。在本研究中，我们通过经鼓膜向中耳接种MRSA（5×10 CFUs）建立了中耳炎大鼠模型。感染1周后给予红色和近红外（NIR）LED照射（655/842 nm；163.2 W/m；每天30分钟，共5天）。扫描电子显微镜显示MRSA生物膜结构明显减少，通过结晶紫染色评估，生物膜生物量显著降低。定量实时聚合酶链反应（qRT-PCR）分析表明，、、和这些对细菌粘附和生物膜形成至关重要的关键基因显著下调。组织学评估进一步显示粘膜增厚和巨噬细胞浸润减少，这得到了离子钙结合衔接分子1（Iba1）表达降低的支持。这些发现表明，红色和近红外LED联合疗法可有效抑制中耳炎中MRSA生物膜的形成和炎症，表明其作为一种新型非抗生素疗法治疗生物膜相关中耳炎的潜力，这可能有助于在临床环境中管理持续性或难治性病例。
