Abstract: Objective To retrospectively analyze the sterility test results of 410 599 blood component bags tested by Shanghai Blood Center, evaluate the occurrence and control of bacterial contamination in blood products in Shanghai, and provide a basis for developing detection strategies and preventive measures. Methods From January, 2017 to December, 2023, Shanghai Blood Center sampled blood components into bags, inoculated them into culture bottles, and used an automatic blood culture system for bacterial screening. Positive bacterial data were statistically analyzed and confirmed. Results The overall bacterial detection rate of three blood components from January 2017 to December 2023 was 0.22‰. A total of 91 bacterial samples were identified by MALDI-TOF MS, with 19 different types of bacteria detected. The most common bacteria in platelet components was Staphylococcus epidermidis (21 cases), while the least common were Bacillus Claudius, Streptococcus lactis, Bacteroides terrestris and Propionibacterium acnes, each detected once. Eight cases of Propionibacterium acnes were found in red blood cell components. Plasma components showed one case of Propionibacterium acnes and one case of Bacillus cereus. The longest positive culture time was Propionibacterium acnes (87.5 hours), and the shortest was Bacillus cereus (2.03 hours). The bacteria detected within 12 hours included Bacillus cereus, Lactococcus gasseri, Bacillus licheniformis, Streptococcus agalactiae, Staphylococcus aureus and Escherichia coli. Within 12~24 hurs Staphylococcus epidermidis, Septicemia, Streptococcus lactis, Bacteroides terrestris and Proteus mirabilis were detected. Conclusion The use of an automated blood culture system for detecting bacterial contamination in blood components in Shanghai provided reliable data from large sample screenings. Anaerobic bacteria were primarily detected the blood components. Coagulase-negative staphylococci were the main bacteria identified in platelets, and this study provides valuable reference for developing relevant standards and procedures for blood product sterility testing.

Key words: Whole blood and blood components, Sterility test, Bacterial contamination, Automated microbial inoculation system, MALDI-TOF MS, Blood safety