Wang Peike, Zeng Yali, Liu Jinbo, Wang Lin, Yang Min, Zhou Jian
Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou, China.
Mianyang 404 Hospital, Mianyang, China.
Microb Pathog. 2025 Feb;199:107208. doi: 10.1016/j.micpath.2024.107208. Epub 2024 Dec 8.
The formation of biofilms enhances bacterial antibiotic resistance, posing significant challenges to clinical treatment. Methicillin-resistant Staphylococcus aureus (MRSA) is a primary pathogen in biofilm-associated infections. Its high antibiotic resistance and incidence rates make it a major clinical challenge, underscoring the urgent need for novel therapeutic strategies. Building on previous research, this study employs nanotechnology to fabricate dihydroartemisinin-chitosan nanoparticles (DHA-CS NPs) and, for the first time, applies them to the treatment of MRSA biofilm infections. The antibacterial and anti-biofilm activities of these compounds were evaluated, and their potential mechanisms of action were preliminarily explored. The results demonstrated that the DHA-CS NPs exhibited a minimum inhibitory concentration (MIC) of15 μg/mLand a minimum bactericidal concentration (MBC) of 30 μg/mL. At 15 μg/mL, the DHA-CS NPs significantly inhibited MRSA biofilm formation (P < 0.001),while at 7.5 μg/mL, they dispersed 67.4 ± 3.77 % of the preformed biofilms (P < 0.001). Scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM) confirmed the disruption of MRSA biofilms. Mechanistic studies, including phenol-sulfuric acid assays, static biofilm microtiter plate assays, and RT-qPCR, revealed that the DHA-CS NPs inhibited the synthesis of extracellular polymeric substances (EPS), suppressed the release of extracellular DNA (eDNA), and downregulated key biofilm-related genes (icaA, sarA, cidA, and agrA). These findings suggest that DHA-CS NPs hold significant promise for inhibiting and eradicating MRSA biofilms, providing a theoretical basis for the development of novel antibiofilm therapies.
生物膜的形成增强了细菌的抗生素耐药性，给临床治疗带来了重大挑战。耐甲氧西林金黄色葡萄球菌（MRSA）是生物膜相关感染的主要病原体。其高抗生素耐药性和发病率使其成为一项重大临床挑战，凸显了对新型治疗策略的迫切需求。基于先前的研究，本研究采用纳米技术制备双氢青蒿素 - 壳聚糖纳米颗粒（DHA - CS NPs），并首次将其应用于治疗MRSA生物膜感染。评估了这些化合物的抗菌和抗生物膜活性，并初步探索了其潜在作用机制。结果表明DHA - CS NPs的最低抑菌浓度（MIC）为15μg/mL，最低杀菌浓度（MBC）为30μg/mL。在15μg/mL时，DHA - CS NPs显著抑制MRSA生物膜形成（P < 0.001），而在7.5μg/mL时，它们分散了67.4±3.77%的预先形成的生物膜（P < 0.001）。扫描电子显微镜（SEM）和共聚焦激光扫描显微镜（CLSM）证实了MRSA生物膜的破坏。包括苯酚 - 硫酸法测定、静态生物膜微量滴定板测定和RT - qPCR在内的机制研究表明，DHA - CS NPs抑制细胞外聚合物（EPS）的合成，抑制细胞外DNA（eDNA）的释放，并下调关键生物膜相关基因（icaA、sarA、cidA和agrA）。这些发现表明DHA - CS NPs在抑制和根除MRSA生物膜方面具有巨大潜力，为新型抗生物膜疗法的开发提供了理论依据。
