Ran Zhaoxia, Hao Minghui, Guo Binxin, Wang Junrui
Department of Laboratory Medicine, Affiliated Hospital of Inner Mongolia Medical University, Hohhot, China.
Medical Experimental Center, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, China.
Front Microbiol. 2025 Aug 4;16:1616536. doi: 10.3389/fmicb.2025.1616536. eCollection 2025.
Extracellular vesicles (EVs) derived from () carry multiple components, such as toxins, antigens, and resistance determinants, whose production is influenced by exposure to β-lactam antibiotics. However, systematic studies on the effects of β-lactam antibiotics on the release and functions of EVs remain limited.
Extracellular vesicles (EVs) were isolated from the OS-MRSA (OS-200) strain by ultracentrifugation, including both EVs untreated with antibiotics and those exposed to sub-inhibitory concentrations of oxacillin (OI-EVs). Proteomic analysis was performed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The functional changes of these EVs were further assessed through erythrocyte hemolysis assays, biofilm formation assays, measurement of cytokines, and cell invasion assays.
Exposure to sub-inhibitory concentrations of oxacillin (half and one-eighth of the minimum inhibitory concentration [MIC]) significantly enhanced the secretion of OI-EVs and increased the abundance of several proteins, including penicillin-binding protein 2, EmrB, Hlg, and enolase, in a concentration-dependent manner. Notably, EV1/2MIC exhibited more pronounced functional changes and enhanced hemolytic activity against rabbit red blood cells. Also, EV1/2MIC exhibited significant promoting effects on biofilm formation of OS-200. Additionally, OI-EVs stimulated the secretion of interleukin-6 and tumor necrosis factor-α by THP-1 macrophages in a dose-dependent manner and demonstrated greater penetration potential into A549 lung epithelial cells.
Exposure to sub-inhibitory concentrations of oxacillin significantly altered the secretion and composition of EVs, highlighting a novel relationship between antimicrobial exposure, exosome biogenesis, and OS-MRSA pathogenicity. These findings provide new insights into how β-lactam antibiotics influence host-pathogen interactions by modulating the secretion of bacterial vesicles.
源自（）的细胞外囊泡（EVs）携带多种成分，如毒素、抗原和耐药决定因子，其产生受β-内酰胺类抗生素暴露的影响。然而，关于β-内酰胺类抗生素对EVs释放和功能影响的系统研究仍然有限。
通过超速离心从OS-MRSA（OS-200）菌株中分离细胞外囊泡（EVs），包括未用抗生素处理的EVs和暴露于亚抑菌浓度苯唑西林的EVs（OI-EVs）。使用液相色谱-串联质谱（LC-MS/MS）进行蛋白质组学分析。通过红细胞溶血试验、生物膜形成试验、细胞因子测量和细胞侵袭试验进一步评估这些EVs的功能变化。
暴露于亚抑菌浓度的苯唑西林（最低抑菌浓度[MIC]的一半和八分之一）显著增强了OI-EVs的分泌，并以浓度依赖的方式增加了几种蛋白质的丰度，包括青霉素结合蛋白2、EmrB、Hlg和烯醇化酶。值得注意的是，EV1/2MIC表现出更明显的功能变化，并增强了对兔红细胞的溶血活性。此外，EV1/2MIC对OS-200的生物膜形成具有显著的促进作用。此外，OI-EVs以剂量依赖的方式刺激THP-1巨噬细胞分泌白细胞介素-6和肿瘤坏死因子-α，并显示出对A549肺上皮细胞更大的穿透潜力。
暴露于亚抑菌浓度的苯唑西林显著改变了EVs的分泌和组成，突出了抗菌暴露、外泌体生物发生和OS-MRSA致病性之间的新关系。这些发现为β-内酰胺类抗生素如何通过调节细菌囊泡的分泌影响宿主-病原体相互作用提供了新的见解。
