title: Establishment of a proficiency panel for an external quality assessment programme for the detection of bacterial contamination in platelet concentrates using rapid and cultural detection methods.
abstract: 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.
  
  
  CONCLUSIONS
  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.
authors: Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
authors: T
authors: T
authors: Vollmer
authors: Institute of Transfusion Medicine and Immunohematology, German Red Cross, Johann Wolfgang Goethe University, Frankfurt, Germany.
authors: M
authors: M
authors: Schmidt
authors: Institute of Transfusion Medicine and Immunohematology, German Red Cross, Johann Wolfgang Goethe University, Frankfurt, Germany.
authors: K
authors: K
authors: Hourfar
authors: German Red Cross Blood Transfusion Service West, Central Laboratory, Hagen, Germany.
authors: V
authors: V
authors: Schottstedt
authors: German Red Cross Blood Transfusion Service West, Central Laboratory, Hagen, Germany.
authors: L
authors: L
authors: Pichl
authors: DRK Blutspendedienst Nord-Ost gemeinnützige GmbH, Plauen, Germany.
authors: K
authors: K
authors: Gubbe
authors: Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
authors: C
authors: C
authors: Knabbe
authors: Institut für Laboratoriums- und Transfusionsmedizin, Herz- und Diabeteszentrum Nordrhein-Westfalen, Universitätsklinik der Ruhr-Universität Bochum, Bad Oeynhausen, Germany.
authors: J
authors: J
authors: Dreier
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development / Q000302:isolation & purification; D001424:Bacterial Infections / Q000382:microbiology / Q000517:prevention & control*; D001792:Blood Platelets / Q000382:microbiology*; D006801:Humans; D059021:Laboratory Proficiency Testing; D017713:Platelet Transfusion; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D012336:RNA, Ribosomal, 16S; D015662:Trimethoprim, Sulfamethoxazole Drug Combination
keywords: EQAP; NAT; bactiflow; platelet bacteria screening; proficiency panel