Growth of bacteria in inoculated platelets: implications for bacteria detection and the extension of platelet storage

• Published in: Transfusion (Philadelphia, Pa.) Pa.), 2000-11, Vol.40 (11), p.1308-1312
• Main Authors: Brecher, Mark E., Holland, Paul V., Pineda, Alvaro A., Tegtmeier, Gary E., Yomtovian, Roslyn
• Format: Article
• Language: English
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Bacteria - growth & development; Biological and medical sciences; Blood Bactericidal Activity; Blood Platelets - microbiology; Blood. Blood and plasma substitutes. Blood products. Blood cells. Blood typing. Plasmapheresis. Apheresis; Humans; Medical sciences; PC(s) = platelet concentrate(s); Transfusions. Complications. Transfusion reactions. Cell and gene therapy
• ISSN: 0041-1132; 1537-2995
• DOI: 10.1046/j.1537-2995.2000.40111308.x

BACKGROUND: Recent reports from Europe have advocated the use of bacterial culturing of platelets on Day 2 or 3 of storage to extend the shelf life of platelets to 7 days, thereby reducing the outdating of platelets and preserving a limited medical resource. To assess the optimal timing, the necessary sensitivity, and the possible efficacy of bacterial detection, the bacterial growth characteristics were reviewed in 165 platelet units, each inoculated on the day of collection with one of the following organisms: Bacillus cereus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens, Staphylococcus aureus, and Staphylococcus epidermidis from four previously published studies. STUDY DESIGN AND METHODS: Quantitative culture data from inoculated platelet concentrates from five sites and four studies were combined into one database and analyzed for bacterial concentration thresholds (≥101, ≥102, ≥103, ≥104, ≥105 CFU/mL) by day of storage. RESULTS: All examples of B. cereus, P. aeruginosa, K. pneumoniae, S. marcescens, and S. aureus had concentrations ≥102 CFU per mL by Day 3 after inoculation. By Day 4, all units with these organisms contained ≥105 CFU per mL. Units contaminated with S. epidermidis showed slower and more varied growth. By Day 3 after inoculation, 81.3 percent had 102 CFU per mL. By Day 4 after inoculation, 46 (95.8%) of 48 units had concentrations ≥102 CFU per mL. CONCLUSION: These experiments suggest that an assay capable of detecting 102 CFU per mL on Day 3 of storage would detect the vast majority of bacterially contaminated platelet units, prevent many cases of platelet‐associated bacterial sepsis, and provide a scientific basis for the extension of the current platelet storage time. It would be expected that a rare, slow‐growing organism could escape such a detection scheme.