Detection of Bacterial Contamination of Platelet Concentrates Produced at Selected Blood Processing Centres

Introduction: The most common microbiological cause of transfusion related morbidity and mortality is bacterial contamination of blood and its cellular components. Out of those cellular components, bacterial contamination of platelet concentrates is more common. Therefore, time-to-time detection of bacterial contamination of platelet concentrates produced at selected blood processing centers is crucial.
Objective: To detect the pathogenic bacteria associated with bacterial contamination of platelet concentrates (PCs) produced at selected blood processing centers.
Methodology: Single donor platelet units, prepared from different donations were used for this cross-sectional study. PCs which were injected into universal culture bottles, which contained Brain Heart Infusion (BHI) broth were observed for any evidence of growth. When there was any evidence of growth, those were inoculated on blood agar and chocolate agar, and a direct smear was prepared to perform a Gram stain. Particular biochemical tests were performed to identify the organism as far as possible. When there was no evidence of growth, only sub-culturing on blood agar and chocolate agar were done. All the bottles those showed negatives were re-incubated, and they were inspected daily. The above procedure was followed for up to 7 days.
Results: Only three samples (3%) showed true positivity for contamination of both culture bottles. Therefore, the percentage of bacterial contamination of platelet concentrates at Day -7 was 3%. The isolated organism in all positive platelet concentrate units was a Gram-positive bacillus of the Bacillus species. Conclusion: Storing platelets at 22 °C up to 6 days and not extending the storage period are necessary to protect the sterility of platelets and to prevent platelet transfusion-associated adverse effects.