A dual‐center evaluation of platelet culture vials to detect the presence of microorganisms in platelets

Abstract

BACKGROUNDMicroorganism contamination of platelets results in a high risk of transfusion‐related sepsis. Here, the ability of culture vials (BD BACTEC Platelet Aerobic/F and Platelet Anaerobic/F vials, Becton, Dickinson and Company) to detect microorganisms in leukoreduced apheresis platelets (LRAPs) and leukoreduced whole blood platelet concentrates (LRWBPCs) was assessed.METHODSLRAPs or LRWBPCs were inoculated into Aerobic/F and Anaerobic/F vials and placed in a blood culturing system (BD BACTEC FX System, Becton, Dickinson and Company) for growth/monitoring over 7 days to detect preexisting contamination during false‐positive testing. Subsequently, platelets were seeded with microorganisms at approximately 10 CFU/mL or approximately 1 CFU/mL to simulate contamination. Aerobic/F and Anaerobic/F vials were inoculated with platelets (sets of 12). Microorganism growth was detected in the BACTEC FX instrument over 7 days. Overall, 2925 vials were tested.RESULTSOf the 1905 vials included in the microorganism detection phase, 63 (3.3%) Aerobic/F and 16 (0.8%) Anaerobic/F vials were both BACTEC FX and subculture negative. From the remaining 1827 vials, two (0.1%) Anaerobic/F vials were false positive; no false positives were observed in Aerobic/F vials, and no false negatives occurred in either vial type. Of the remaining 1825 vials (99.9%), 955 Aerobic/F and 870 Anaerobic/F vials were true positives. The mean‐time‐to‐detection range was 8.5 to 77 hours. All true‐positive Aerobic/F and Anaerobic/F vials showed 100% agreement with subculture for positive identification of seeded microorganisms.CONCLUSIONAerobic/F and Anaerobic/F vials facilitate contamination detection in LRAPs and LRWBPCs down to approximately 1 CFU/mL. These results support the use of Aerobic/F and Anaerobic/F vials for quality control testing of platelets before transfusion.

Increased frequency of false‐positive bacterial detection after implementation of new guidelines for large‐volume delayed sampling of platelets

“…As previously described, IR bottles were sent for culturing to identify potential organisms, and if culture positive were termed TP or if culture negative were termed FP. Of the 47 IR BPAs, 31.9% 15 and 4.13% of BPNs). Of the 13 ANRSP that were associated to TP split product, 6 (46.2%) were reactive, while of the 108 ANRSP that were associated to FP, only 1.9% were reactive.…”

“…As previously described, IR bottles were sent for culturing to identify potential organisms, and if culture positive were termed TP or if culture negative were termed FP. Of the 47 IR BPAs, 31.9% 15 were TP and 68.1% (32) were FP. Of the 105 IR BPNs, 46.7% (49) were TP and 53.3% (56) were FP.…”

“…14 It has been shown that pathogen load of as little as one colony forming unit/mL in aerobic and anaerobic bottles will allow BD detection systems to alarm. 15 It is also well documented that passive surveillance of possible STRs is under-reported by clinical teams. In a study on active surveillance, where platelets were cultured at the time of release for transfusion, the bacterial contamination rate noted was 0.004% (20 of 51,440 units transfused).…”

“…The National Health Service Blood and Transplant (Bristol, UK) showed increased safety of platelets with an approximate 90% decrease in transfusion‐related transmissions between 2011 and 2016 with the implementation of inoculation of 8 mL of platelets into each aerobic and anaerobic bottles (sampled at 36–48 h after collection, released at 6 h after inoculation), in comparison with the 5 years prior where only diversion of the first 30 mL of blood collected and donor arm disinfection had been implemented 14 . It has been shown that pathogen load of as little as one colony forming unit/mL in aerobic and anaerobic bottles will allow BD detection systems to alarm 15 …”