Abstract
Background:
Bacterial contamination of stem cell products may causefatal clinical consequences in immunosuppressed patients. Sterility testingof blood stem cell products is often done with blood culture bottles prior tocryopreservation. It is not known, if cell suspension components as e.g.DMSO impair the assay sensitivity and if an aliquot of 1 ml is great enoughfor the reliable ...
Abstract
Background:
Bacterial contamination of stem cell products may causefatal clinical consequences in immunosuppressed patients. Sterility testingof blood stem cell products is often done with blood culture bottles prior tocryopreservation. It is not known, if cell suspension components as e.g.DMSO impair the assay sensitivity and if an aliquot of 1 ml is great enoughfor the reliable detection.Aim:Validation of the sterility testing system for blood stem cell cryo-preservation.
Methods:
Aerobic and anaerobic blood culture bottles (BACT-Alert, bio-Merieux) were incubated with 1 ml of 10% DMSO-containing blood stem cellsuspension. Bacteria as listed by the Pharmacopoea Europaea and in housebacteria including Haemophilus influenzae ATCC 10211 were added (1 mlwith 10–100 bacterial colony forming units). Incubation was at 35°C for7 days for the bottles and controls (no stem cell suspension or no bacteria).
Results:
All blood culture bottles became positive after 1–3 days. Controlswithout bacteria were negative, and the control with H. influenzae, butwithout stem cells suspension was negative. The other controls were po-sitive as expected.
Conclusion:
Bacterial contamination of blood stem cell products can beidentified by using blood culture bottles in the presence of DMSO. Analiquot of 1 ml per cryoconservation bag was great enough for the reliabledetection.