title: Bench Test for the Detection of Bacterial Contamination in Platelet Concentrates Using Rapid and Cultural Detection Methods with a Standardized Proficiency Panel.
abstract: BACKGROUND
  The most frequent infectious complication in transfusion therapy in developed countries is related to the bacterial contamination of platelet concentrates (PCs). Rapid and cultural screening methods for bacterial detection in platelets are available, but external performance evaluation, especially of rapid methods, has been difficult to realize so far. Here we summarize the results of three individual collaborative trials using an external quality assessment program (EQAP) for the application of current rapid and cultural screening methods.
  
  
  METHODS
  Three different modules were available for the detection of bacterial contamination: module 1: rapid methods, module 2: culture methods, module 3: bacterial identification methods. The sample set-up included up to six different bacterial strains, 1-2 negative samples and 4-6 positive samples with stabilized bacterial cell counts (approximately 10(3)/10(4)/10(5) CFU/ml). Time schedule for testing was limited (module 1: 6 h, module 2 and 3: 7 days).
  
  
  RESULTS
  Samples of module 1 were analyzed with two different rapid methods (BactiFlow, NAT). The results of the three individual collaborative trials showed that all participants detected the negative samples with both assays correctly. Samples spiked with 10(4) to 10(5) CFU/ml of bacteria obtained positive results with both rapid screening methods, whereas samples spiked with only 10(3) CFU/ml disclosed a lower number of correctly identified positive results by NAT (86.6-93.8% sensitivity) compared to BactiFlow (100% sensitivity). The results for modules 2 and 3 revealed a 100% diagnostic sensitivity and specificity in all three collaborative trials.
  
  
  CONCLUSIONS
  This proficiency panel facilitates the verification of the analytical sensitivity of rapid and cultural bacterial detection systems under controlled routine conditions. The concept of samples provided in this EQAP has three main advantages: i) samples can be examined by both rapid and culture methods, ii) the provided material is matrix-equivalent, and iii) the sample material is ready-to-use.
authors.affiliation: Institute for Laboratory and Transfusion Medicine, Heart and Diabetes Center North Rhine Westphalia, Bad Oeynhausen, Germany.
authors.forename: Tanja
authors.initials: T
authors.lastname: Vollmer
authors.affiliation: Institute for Laboratory and Transfusion Medicine, Heart and Diabetes Center North Rhine Westphalia, Bad Oeynhausen, Germany.
authors.forename: Cornelius
authors.initials: C
authors.lastname: Knabbe
authors.affiliation: Reference Institute for Bioanalytics, Bonn, Germany.
authors.forename: Wolf-Jochen
authors.initials: WJ
authors.lastname: Geilenkeuser
authors.affiliation: Institute of Transfusion Medicine and Immunohematology, German Red Cross, Johann Wolfgang Goethe University, Frankfurt/M., Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.affiliation: Institute for Laboratory and Transfusion Medicine, Heart and Diabetes Center North Rhine Westphalia, Bad Oeynhausen, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Dreier
keywords: BactiFlow; Collaborative trial; NAT; Platelet bacteria screening; Rapid methods