- Adipose-derived stem cells (ADSCs) are classified as advanced therapy medicinal products (ATMPs) and are increasingly used in research, clinical trials, and regenerative medicine applications.
- Sterility assurance is critical for ATMP safety, yet traditional pharmacopeial sterility tests (e.g., 14-day culture per Ph. Eur. 2.6.1 and USP <71>) are time-intensive and can delay product release.
- BACTEC is an automated, continuously monitored blood culture system designed to detect viable microorganisms in liquid biological matrices.
- While automated blood culture systems offer rapid and sensitive detection, their use for ATMP quality control requires rigorous validation to demonstrate equivalence to compendial methods, particularly in complex matrices such as Ringer’s Lactate.
Key Findings
Szabłowska-Gadomska et al. (2026) evaluated the BACTEC automated blood culture system for sterility testing of adipose-derived stem cell–based products formulated in Ringer’s Lactate. Validation followed a four-stage approach—assessment of sterile media, growth promotion, matrix suitability, and comparability to pharmacopeial sterility testing—performed in accordance with European Pharmacopoeia requirements using seven aerobic and three anaerobic reference microorganisms.¹
- Robust detection at low inoculum levels: BACTEC detected all reference microorganisms at ≥ 5 CFU with repeatability exceeding 95%, demonstrating high analytical sensitivity and method robustness.
- Accelerated time to detection: All microorganisms were detected within 24–72 h, enabling substantially faster sterility confirmation than conventional 14-day culture methods.
- Full concordance with compendial testing: Comparison with the pharmacopeial sterility test showed absolute agreement (Cohen’s κ = 1.0) and strong correlation of detection times (r = 0.92, p < 0.001), confirming methodological equivalence.
- Suitability for ATMP quality control: Successful validation supports the use of BACTEC in routine sterility testing of ATMP suspensions, including stem cell–based products prepared in Ringer’s Lactate, in alignment with regulatory expectations.
Bigger Picture
This study reinforces the role of automated blood culture systems such as BACTEC as reliable, rapid alternatives to traditional sterility assays for cell-based ATMPs. By providing sensitivity and specificity equivalent to compendial methods within a significantly shorter timeframe, rapid sterility testing addresses a key manufacturing constraint for time-sensitive therapies. Rigorous validation against pharmacopeial criteria remains essential for regulatory acceptance, but validated approaches like BACTEC integration into ATMP quality systems may accelerate clinical release, enhance microbiological risk management, and support the broader adoption of rapid sterility testing strategies.
References:
- Szabłowska Gadomska et al. 2026. Validation of the Bactec System for Sterility Testing of Advanced Therapy Medicinal Product Suspensions in Ringer’s Lactate. Journal of Pharmaceutical and Biomedical Analysis.
