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Establishment of a proficiency panel for an external quality assessment programme for the detection of bacterial
T Vollmer1, M Schmidt2, K Hourfar2
1Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
Background:
Platelet concentrates (PCs) are the main focus regarding the residual risk of transfusion-transmitted bacterial infections. Rapid screening methods for bacterial detection in platelets have been optimized over the last decade, but their external evaluation represents a complicated process. We developed a new type of proficiency panel for bacterial detection in PCs using currently available screening methods (especially rapid methods) suitable for external quality assessment programmes (EQAP).
Methods:
PC samples were inoculated with different bacteria at two concentrations (10E+03 CFU/ml, 10E+05 CFU/ml) and stored under temperature-controlled conditions (1-5 days). Bacterial growth was further prevented by the addition of 0-20 μg/ml cotrimoxazole. Samples were analysed prior to and after storage using rapid detection methods (Bactiflow (BF), bacteria-generic NAT) and cultural methods to determine the influence of storage and antibiotic treatment on bacterial counts and the result outcome. A pilot EQAP was performed with four participants.
Results:
Testing under the evaluated conditions demonstrated that bacterial counts remained constant prior to and after storage. The supplementation of 10 μg/ml cotrimoxazole did not influence bacterial detection using the two rapid detection methods BF and NAT. Furthermore, the detection of bacteria using cultural methods is still possible despite of antibiotic supplementation. The pilot EQAP confirmed these results. A storage time of up to 3 days proved practicable, showing no considerable influence on bacterial count and outcome of test results.
Conclusion:
The established proficiency panel provided PC matrix-conform samples with stabilized bacterial counts which can be analysed in parallel by rapid and cultural detection methods.
Insights
A new proficiency panel for bacterial detection in platelet concentrates (PCs) was developed. This panel ensures accurate external quality assessment for rapid screening methods, improving transfusion safety by stabilizing bacterial counts.
Area of Science:
- Transfusion Medicine
- Microbiology
- Quality Assurance
Background:
- Platelet concentrates (PCs) pose a risk of transfusion-transmitted bacterial infections.
- Optimized rapid screening methods for bacterial detection in PCs require robust external evaluation.
- A novel proficiency panel was created for assessing bacterial detection in PCs.
Purpose of the Study:
- To develop a proficiency panel for external quality assessment (EQA) of bacterial detection in platelet concentrates.
- To evaluate the suitability of the panel for current rapid and cultural screening methods.
- To assess the impact of storage and antibiotic cotrimoxazole on bacterial detection.
Main Methods:
- Platelet concentrate samples were inoculated with bacteria at varying concentrations and stored (1-5 days).
- Cotrimoxazole was added to samples to inhibit bacterial growth.
- Samples were analyzed pre- and post-storage using rapid (Bactiflow, NAT) and cultural methods.
- A pilot external quality assessment program (EQAP) was conducted with four participants.
Main Results:
- Bacterial counts remained stable before and after storage.
- Cotrimoxazole supplementation (10 μg/ml) did not affect detection by rapid methods (BF, NAT).
- Antibiotic supplementation did not prevent bacterial detection by cultural methods.
- Pilot EQAP results confirmed the panel's effectiveness; 3-day storage was practicable.
Conclusions:
- The developed proficiency panel provides matrix-conform PC samples with stabilized bacterial counts.
- The panel enables parallel analysis by both rapid and cultural detection methods.
- This facilitates reliable external quality assessment for bacterial screening in platelet concentrates.
