Mitchell Adam J, Gray Warren D, Schroeder Max, Yi Hong, Taylor Jeannette V, Dillard Rebecca S, Ke Zunlong, Wright Elizabeth R, Stephens David, Roback John D, Searles Charles D
Division of Cardiology, Department of Medicine, Emory University, Atlanta, Georgia, United States of America.
Division of Infectious Disease, Department of Medicine, Emory University, Atlanta, Georgia, United States of America.
PLoS One. 2016 Oct 19;11(10):e0163582. doi: 10.1371/journal.pone.0163582. eCollection 2016.
Red blood cell (RBC) transfusions are a common, life-saving therapy for many patients, but they have also been associated with poor clinical outcomes. We identified unusual, pleomorphic structures in human RBC transfusion units by negative-stain electron microscopy that appeared identical to those previously reported to be bacteria in healthy human blood samples. The presence of viable, replicating bacteria in stored blood could explain poor outcomes in transfusion recipients and have major implications for transfusion medicine. Here, we investigated the possibility that these structures were bacteria.
Flow cytometry, miRNA analysis, protein analysis, and additional electron microscopy studies strongly indicated that the pleomorphic structures in the supernatant of stored RBCs were RBC-derived microparticles (RMPs). Bacterial 16S rDNA PCR amplified from these samples were sequenced and was found to be highly similar to species that are known to commonly contaminate laboratory reagents.
These studies suggest that pleomorphic structures identified in human blood are RMPs and not bacteria, and they provide an example in which laboratory contaminants may can mislead investigators.
红细胞（RBC）输血是许多患者常用的救命疗法，但也与不良临床结局相关。我们通过负染色电子显微镜在人类RBC输血单位中发现了异常的多形结构，这些结构与先前报道的健康人类血液样本中的细菌相同。储存血液中存在有活力、可复制的细菌可能解释了输血受者的不良结局，并对输血医学具有重大影响。在此，我们研究了这些结构是细菌的可能性。
流式细胞术、miRNA分析、蛋白质分析以及额外的电子显微镜研究有力地表明，储存RBC上清液中的多形结构是红细胞衍生的微粒（RMPs）。从这些样本中扩增的细菌16S rDNA进行了测序，发现与已知常污染实验室试剂的物种高度相似。
这些研究表明，在人类血液中鉴定出的多形结构是RMPs而非细菌，它们提供了一个实验室污染物可能误导研究人员的例子。
