Validation of BacT/ALERT plastic culture bottles for use in testing of whole-blood-derived leukoreduced platelet-rich-plasma-derived platelets.

Abstract

Bacterial detection of platelet (PLT)-rich-plasma (PRP)-derived PLTs presents unique challenges for countries that do not allow pooling before storage. This study validated the BacT/ALERT for use in testing pooled PRP-derived PLTs with nine contaminating organisms. Isolates of Bacillus cereus, Enterobacter cloacae, Escherichia coli, Klebsiella pneumoniae, Staphylococcus aureus, Staphylococcus epidermidis, Serratia marcescens, Streptococcus viridans, and Propionibacterium acnes were inoculated into two PRP-derived PLT pools (target, 10 and 100 colony-forming units [CFUs]/mL; actual recovered concentrations, 5 and 90 CFUs/mL). Four milliliters of each postbacterial inoculation sample was inoculated into both plastic aerobic and anaerobic bottles and 0.5 mL was plated onto blood agar. All organisms (excluding P. acnes) were detected in 8.2 to 22.0 and 7.6 to 20.3 hours (10 and 100 CFUs/mL, respectively) and the mean time to detection was 15.0 and 13.1 hours (10 and 100 CFUs/mL, respective). P. acnes was detected with the anaerobic bottles in a mean of 74.9 and 64.3 hours (10 and 100 CFUs/mL, respectively). With E. cloacae, E. coli, K. pneumoniae, S. marcescens, and S. viridans detection with the anaerobic bottles was faster or equivalent to the detection with the aerobic bottles. This was most notable with S. viridans where the anaerobic bottle was reactive on average 21.6 and 10.8 hours (10 and 100 CFUs/mL, respectively) faster than the aerobic bottle. This study validates the use of the BacT/ALERT system for the detection of bacteria in PRP-derived PLTs in a pooled format. Overall, the use of the BacT/ALERT system allowed the detection of pooled PRP-derived PLTs inoculated with nine bacteria at 10 and 100 CFUs per mL in 7.6 to 22.0 hours (excluding P. acnes).