LAUSR

Platelet concentrates (PCs), stored at room temperature, have the highest risk of bacterial contamination among labile blood components. We report the case of an apheresis platelet product contaminated with Klebsiella oxytoca showing an amorphous mass on the platelet's bag. A 66-year-old patient with myelodysplastic syndrome under prophylactic platelet transfusion support experienced malaise, chills, and a sudden drop in blood pressure 15 minutes after starting the transfusion of a single donor platelet's unit. The platelet unit had not been pathogen reduced or screened for bacterial contamination. The patient needed admission to the critical care ward due to septic shock. Microbiological cultures were performed on the patient's blood and the transfused bag. Bacterial cultures were positive on both samples, and K. oxytoca was isolated. It was reported to our blood center for further investigation. The involved component corresponded to a double-dose donation and was transfused on day 3 after collection. The remaining untransfused sister unit was located in another hospital, and it was returned to the blood center where a large white amorphous mass was noted (Figures 1 and 2). K. oxytoca was also isolated in this second portion. Antibiograms from the three isolates (patient and PCs) were the same. Therefore, the mass was likely to be a platelet aggregate caused by the growth of bacteria. The source of