PDF(Pubmed)
Abstract：
Background: Bacterial aggregation has been well described to occur in synovial fluid, but it is unknown if bacteria form aggregates in body fluids beyond the synovial fluid. Consequently, this translational study evaluated the ability to form bacterial aggregates in different pleural fluids. Methods: Four of the most common causes of thoracic empyema-Streptococcus mitis, Streptococcus pneumoniae, Staphylococcus aureus, and Pseudomonas aeruginosa-were used here. The different pleural fluids included one transudative and two exudative pleural fluids. Twenty-four-well microwell plates were used to form the aggregates with the aid of an incubating shaker at different dynamic conditions (120 RPM, 30 RPM, and static). The aggregates were then visualized with SEM and evaluated for antibiotic resistance and the ability of tissue plasminogen activator (TPA) to dissolve the aggregates. Statistical comparisons were made between the different groups. Results: Bacterial aggregates formed at high shaking speeds in all pleural fluid types, but no aggregates were seen in TSB. When a low shaking speed (30 RPM) was used, only exudative pleural fluid with a high protein content formed aggregates. No aggregates formed under static conditions. Furthermore, there was a statistical difference in the CFU/mL of bacteria present after antibiotics were administered compared to bacteria with no antibiotics (p < 0.005) and when TPA plus antibiotics were administered compared to antibiotics alone (p < 0.005). Conclusions: This study shows that bacteria can form aggregates in pleural fluid and at dynamic conditions similar to those seen in vivo with thoracic empyema. Importantly, this study provides a pathophysiological underpinning for the reason why antibiotics alone have a limited utility in treating empyema.
摘要：
背景：已经很好地描述了细菌聚集发生在滑液中，但是细菌是否在滑液之外的体液中形成聚集体是未知的。因此,这项转化研究评估了在不同胸膜液中形成细菌聚集体的能力.方法：胸腔脓胸最常见的四种原因-链球菌炎，肺炎链球菌,金黄色葡萄球菌,和铜绿假单胞菌在这里使用。不同的胸水包括一种渗出性和两种渗出性胸水。在不同的动态条件下（120RPM，30RPM,和静态）。然后用SEM观察聚集体,并评估抗生素抗性和组织纤溶酶原激活物(TPA)溶解聚集体的能力。在不同组之间进行统计比较。结果：在所有胸膜积液类型中，以高摇动速度形成细菌聚集体，但在TSB中没有发现聚集体。当使用低振动速度（30转/分）时，只有蛋白质含量高的渗出性胸膜液形成聚集体。在静态条件下没有形成聚集体。此外，与不使用抗生素的细菌相比,使用抗生素后存在的细菌的CFU/mL存在统计学差异(p<0.005),以及使用TPA+抗生素时与单独使用抗生素相比,存在统计学差异(p<0.005).结论：这项研究表明，细菌可以在胸腔积液中形成聚集体，并且在动态条件下与体内胸腔脓胸相似。重要的是,本研究为单用抗生素治疗脓胸的效用有限提供了病理生理学基础。
