Evaluation of the Efficacy of Flow Cytometry in Detecting Bacterial Contamination in Platelets

Introduction: Bacterial contamination of platelet products is a major risk of infections in blood transfusion. Due to their storage conditions at room temperatures (22 to 24°C), cases of septicemia and even death caused by platelet injection have been reported. Therefore, use of appropriate diagnostic methods can improve the health of this product. In this study, flow cytometry was used to detect contaminated platelet units.

Methods: This study was a diagnostic interventional type. 15 units of platelet concentrate was prepared at a minimum interval time after production. Staphylococcus epidermidis and Escherichia coli (E. coli) bacteria were each added to 6 platelet bags, with a concentration of 10 CFU / ml, while 3 bags were used as negative control. Platelets were stored in a shaking incubator at 22 - 24°C, for 0, 6, 24 and 48 hour-intervals after inoculation. Samples were then taken at 1 ml volume and evaluated by flow cytometry.

Results: The sensitivity of the flow cytometry method to detect contaminated platelet units in infections with both Staphylococcus epidermidis and E. coli, in a 1 ml volume in all samples at 0, 6, 22 and 24 hours after inoculation, was 100%, and the number of bacteria increased in 24 hours of incubation, except for E. coli that decreased after 24 hours.

Conclusion: This study shows that flow cytometry can be a useful method for detecting bacterial contamination in platelets, and can detect low concentrations (10 CFU / ml) of bacteria in small volumes of sample (ml) in a short time.