1 Department of Microbiology and Infectious Diseases, Faculty of Medicine, Toho University, Tokyo, Japan.
2 Department of Surgery, Graduate School of Medicine, Toho University, Chiba, Japan.
Microb Drug Resist. 2019 Jun;25(5):668-676. doi: 10.1089/mdr.2019.0068. Epub 2019 May 17.
Characteristics of infections include biofilm formation, leading to the spread of bacteria to the bloodstream causing sepsis and metastatic infections. In particular, in methicillin-resistant (MRSA) infections, biofilm formation critically hampers treatment and causes poor prognosis. We explored the biofilm formation of MRSA in the presence or absence of plasma and compared morphological characteristics, accumulation of antibiotics, and resistance to bactericidal activity, using continuous optimizing confocal reflection microscopy. Addition of plasma significantly increased biofilm formation, which is characterized by an uneven surface and aggregation of bacteria (hereafter plasma biofilm). The flow-cell system, which enabled a continuous supply of plasma, accelerated biofilm formation in both the tested strains of MRSA (BAA1556 and N315). Accumulation of green fluorescence-labeled vancomycin was observed within 5 minutes in the plasma-free biofilm, but not in the plasma biofilm. Delay of accumulation was also observed for daptomycin in plasma biofilm. Plasma biofilm bacteria were more resistant to anti-MRSA antibiotics than plasma-free biofilm bacteria. These data demonstrate that the plasma biofilm of is substantially different from the plasma-free biofilm. Plasma biofilm, especially in the flow-cell system, could be a clinically relevant model to analyze MRSA infections and treatment.
感染的特征包括生物膜的形成，这导致细菌扩散到血液中引起败血症和转移性感染。特别是在耐甲氧西林金黄色葡萄球菌（MRSA）感染中，生物膜的形成严重阻碍了治疗，并导致预后不良。我们使用连续优化共聚焦反射显微镜，在有或没有血浆的情况下探索了 MRSA 的生物膜形成，并比较了形态特征、抗生素积累和对杀菌活性的抗性。添加血浆显著增加了生物膜的形成，其特征是表面不均匀和细菌聚集（以下称为血浆生物膜）。流动池系统能够连续供应血浆，加速了两种测试的 MRSA 菌株（BAA1556 和 N315）的生物膜形成。在无血浆的生物膜中，在 5 分钟内观察到绿色荧光标记的万古霉素的积累，但在血浆生物膜中没有观察到。在血浆生物膜中，达托霉素的积累也出现了延迟。血浆生物膜中的细菌对抗 MRSA 抗生素的耐药性比无血浆生物膜中的细菌更强。这些数据表明，的血浆生物膜与无血浆生物膜有很大的不同。血浆生物膜，特别是在流动池系统中，可能是分析 MRSA 感染和治疗的临床相关模型。
