Brecher M E, Hogan J J, Boothe G, Kerr A, McClannan L, Jacobs M R, Yomtovian R, Chongokolwatana V, Tegtmeier G, Henderson S
University of North Carolina at Chapel Hill.
Transfusion. 1994 Sep;34(9):750-5. doi: 10.1046/j.1537-2995.1994.34994378273.x.
Currently, the maximum outdate for platelets is 5 days, because of the increasing chance of bacterial growth over time. Various methods for rapid detection of bacterial contamination of blood components have been described, with mixed results and no general acceptance. A recently described, molecular biologic approach for the detection of bacterial contamination involves a chemiluminescence-linked universal DNA bacterial probe to a highly conserved bacterial region of ribosomal RNA (rRNA).
A multicenter trial of a chemiluminescence-linked universal bacterial rRNA probe for the detection of bacterial contamination in platelet concentrates is described. At each of five sites, platelet concentrates (no older than 1 day from date of phlebotomy) were inoculated in triplicate with isolates of four bacterial species (Pseudomonas aeruginosa, Bacillus cereus, Staphylococcus epidermidis, and Staphylococcus aureus) to a final concentration of 10 to 50 colony-forming units (CFUs) per mL and in triplicate to a final concentration of 1000 CFUs per mL. At one site, an additional 6 platelet concentrates were inoculated with sterile saline to serve as controls. Inoculated units were then subjected periodically to quantitative cultures and probe analyses. A total of 126 platelet concentrates were studied over a period of 7 days (120 inoculated with bacteria and 6 with sterile saline).
This assay was, in some cases, able to detect S. aureus bacterial contamination in the range of 100 to 1000 CFUs per mL; the majority of samples (B. cereus, P. aeruginosa, S. aureus, and S. epidermidis) with contamination exceeding 10(4) CFUs per mL; and all samples with contamination of 2.1 x 10(5) CFUs per mL or greater. Increasing the sample size from the recommended 0.4 mL to 1.0 mL resulted in an unacceptable loss of specificity (83.3%).
The routine use of this assay would be expected to result in a decreased risk of septic platelet transfusion reactions and could lead to a lengthening of the current 5 day storage period for platelets. Further, the pooling of random-donor platelet concentrates before storage instead of immediately before transfusion may be possible if this rRNA probe is employed to detect bacteria in the pool.
目前，血小板的最长保存期为5天，因为随着时间推移细菌生长的可能性增加。已经描述了多种快速检测血液成分细菌污染的方法，结果不一，未得到普遍认可。最近描述的一种检测细菌污染的分子生物学方法涉及一种与核糖体RNA（rRNA）高度保守细菌区域相连的化学发光通用DNA细菌探针。
描述了一项关于化学发光通用细菌rRNA探针检测浓缩血小板中细菌污染的多中心试验。在五个地点中的每个地点，将浓缩血小板（采血日期不超过1天）一式三份接种四种细菌（铜绿假单胞菌、蜡样芽孢杆菌、表皮葡萄球菌和金黄色葡萄球菌）的分离株，最终浓度为每毫升10至50个菌落形成单位（CFU），一式三份接种至最终浓度为每毫升1000 CFU。在一个地点，另外6份浓缩血小板接种无菌盐水作为对照。然后对接种的单位定期进行定量培养和探针分析。在7天内共研究了126份浓缩血小板（120份接种细菌，6份接种无菌盐水）。
在某些情况下，该检测方法能够检测出每毫升100至1000 CFU范围内的金黄色葡萄球菌细菌污染；大多数污染超过每毫升10⁴ CFU的样本（蜡样芽孢杆菌、铜绿假单胞菌、金黄色葡萄球菌和表皮葡萄球菌）；以及所有污染为每毫升2.1×10⁵ CFU或更高的样本。将样本量从推荐的0.4 mL增加到1.0 mL导致特异性不可接受地降低（83.3%）。
预期该检测方法的常规使用将降低败血性血小板输血反应的风险，并可能延长目前血小板5天的保存期。此外，如果采用这种rRNA探针检测混合浓缩血小板中的细菌，那么在储存前而不是输血前立即混合随机供者浓缩血小板可能是可行的。
