Comparison of Methods for Detecting Bacterial Contamination in Platelet Concentrates

Kwon, So Yong; Choi, Kyoung Young; Lim, A Hyun; Park, Kyoung Un; Cho, Nam Sun

Abstract

BACKGROUND
Bacterial contamination of platelets represents the highest infectious risk for a transfusion. In this study, we evaluated 2 culture-based systems that have been approved by the US FDA for bacterial screening.
METHODS
Platelet concentrates were inoculated with 5 bacterial species to give a final concentration of 10(0), 10(1) and 10(2) CFU/mL. Samples for culture were taken immediately after inoculation (0 hr sample) and after 24 hrs (24 hr sample). For the BacT/ALERT 3D system, a 10 mL sample was inoculated into an aerobic culture bottle and incubated for 7 days. For the Pall eBDS system, 3 mL samples were taken from the 0 hr and 24 hr samples, respectively. The samples were incubated for 24 hrs and 30 hrs.
RESULTS
Both systems detected all inoculated units both in the 0 hr and 24 hr samples, except for units inoculated with K. pneumoniae. Eleven units out of 30 units inoculated with K. pneumoniae were detected by the BacT/ALERT 3D system in the 24 hr samples. The Pall eBDS system detected 8 of 30 units in the 24 hr samples.
CONCLUSION
Implementation of either system will decrease the risk of transfusing bacterially contaminated platelets. However, testing for bacterial contamination will not completely prevent septic transfusion reactions; pathogen inactivation that is now available should also be considered as an alternative method to reduce the risk of bacterial contamination.