Salem Akel1, Joan Lorenz, Donna Regan. 1. St Louis Cord Blood Bank and Cellular Therapy Laboratory, SSM Cardinal Glennon Children's Medical Center, St Louis, Missouri.
Abstract
BACKGROUND: The St Louis Cord Blood Bank submitted a biologics license application for cord blood (CB) products processed by PrepaCyte-CB (BioE), supported with a validation study of a microbial detection system for product sterility testing (BACTEC-FX, Becton Dickinson). This article provides the validation approach followed to fulfill Food and Drug Administration requirements pertinent to sterility testing method. STUDY DESIGN AND METHODS: System qualification, culture media quality verification, and validation of CB processing by-product (CB-BP) sample as surrogate to final product for sterility testing were followed by studies evaluating method sensitivity, specificity, reproducibility, ruggedness or robustness, and bacteriostatic or fungistatic effect of CB-BP sample. CB-BP cultures and control samples were formulated using BACTEC Plus Aerobic/F, Plus Anaerobic/F, and Myco F/Lytic media. Samples were seeded with selected test organisms (n = 13 at 10-100 colony-forming units [CFUs] per vial) and cultured for 14 days (bacterial) and 30 days (fungal). RESULTS: Under testing conditions, no stasis effect of test sample on microbial growth and no false-positive or false-negative results were reported. Although a 7-day culture was sufficient to detect all validation test organisms seeded at ≤ 26 CFUs/vial, growth in actual product sterility testing practice may require a 10- to 14-day culture. Assay reproducibility was uncertain at very low bioburden (< 10 CFUs/vial). Growth time to detection neither varied between different media lots nor prolonged in culture vials with loading delay (6-8 hr at room temperature). CONCLUSION: BACTEC-FX culture and detection system and BACTEC media formulae have high detection capability and can be effectively validated for sterility testing of CB products.
BACKGROUND: The St Louis Cord Blood Bank submitted a biologics license application for cord blood (CB) products processed by PrepaCyte-CB (BioE), supported with a validation study of a microbial detection system for product sterility testing (BACTEC-FX, Becton Dickinson). This article provides the validation approach followed to fulfill Food and Drug Administration requirements pertinent to sterility testing method. STUDY DESIGN AND METHODS: System qualification, culture media quality verification, and validation of CB processing by-product (CB-BP) sample as surrogate to final product for sterility testing were followed by studies evaluating method sensitivity, specificity, reproducibility, ruggedness or robustness, and bacteriostatic or fungistatic effect of CB-BP sample. CB-BP cultures and control samples were formulated using BACTEC Plus Aerobic/F, Plus Anaerobic/F, and Myco F/Lytic media. Samples were seeded with selected test organisms (n = 13 at 10-100 colony-forming units [CFUs] per vial) and cultured for 14 days (bacterial) and 30 days (fungal). RESULTS: Under testing conditions, no stasis effect of test sample on microbial growth and no false-positive or false-negative results were reported. Although a 7-day culture was sufficient to detect all validation test organisms seeded at ≤ 26 CFUs/vial, growth in actual product sterility testing practice may require a 10- to 14-day culture. Assay reproducibility was uncertain at very low bioburden (< 10 CFUs/vial). Growth time to detection neither varied between different media lots nor prolonged in culture vials with loading delay (6-8 hr at room temperature). CONCLUSION: BACTEC-FX culture and detection system and BACTEC media formulae have high detection capability and can be effectively validated for sterility testing of CB products.