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Detection of bacterial contamination in platelet concentrates by a sensitive flow cytometric assay ( BactiFlow ): a multicentre validation study
Author(s) -
Vollmer T.,
Dreier J.,
Schottstedt V.,
Bux J.,
Taper K.,
Sibrowski W.,
Kleesiek K.,
Knabbe C.
Publication year - 2012
Publication title -
transfusion medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.471
H-Index - 59
eISSN - 1365-3148
pISSN - 0958-7578
DOI - 10.1111/j.1365-3148.2012.01166.x
Subject(s) - streptococcus mitis , microbiology and biotechnology , medicine , microbiological culture , blood culture , staphylococcus , bacterial growth , flow cytometry , streptococcus , andrology , staphylococcus aureus , biology , immunology , bacteria , antibiotics , genetics
Background Bacterial contamination of platelet concentrates ( PCs ) still represents an ongoing risk. As a result of septic complications, particularly observed with older PCs , the shelf life of PCs has been reduced in Germany to 4 days. In this study, bacterial screening of PCs by BactiFlow ( BF ) flow cytometry was introduced in three German blood services to evaluate the robustness and applicability of the assay. Results were used to discuss the potential for the extension of PC shelf life to 5 days. Study design and methods A total of 1956 PCs were tested on days 4 or 5+ after PC production using the BF , whereas the BacT /Alert culture system served as reference method. Results Two PCs were confirmed positive by culture only and were identified as Propionibacterium acnes and Staphylococcus species. Two PCs were confirmed positive for Streptococcus mitis by BF and culture. Additionally, two PCs were culture‐positive only in one culture bottle (aerobic: S. mitis and anaerobic: S. hominis ). Retrospective analysis of bacterial growth kinetics provide the indication that corresponding bacterial titres were most likely below the BF analytical detection limit (<150 CFU mL −1 ) and had probably no transfusion relevance. All remaining specimens were tested negative. Conclusions Testing of PCs by BF was successfully implemented. The BF proved sufficient as a rapid screening method to improve PC safety. This study further provides data supporting the extension of PC shelf life to 5 days after negative BF testing on day 4.