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Schmidt M.,Goethe University Frankfurt | Hourfar M.K.,Goethe University Frankfurt | Sireis W.,Goethe University Frankfurt | Pfeiffer U.,Goethe University Frankfurt | And 4 more authors.
Transfusion | Year: 2015

BACKGROUND To increase blood safety, various procedures are currently implemented, including donor selection, optimized donor arm disinfection, and diversion. In addition, pathogen inactivation (PI) techniques can be used for platelets (PLTs) and plasma concentrates. STUDY DESIGN AND METHODS This study investigated the clinical efficacy of an inactivation technique for different blood components at two time points (12 and 35.5 hr). Eight transfusion-relevant bacterial strains were spiked at two different concentrations (100 and 1000 colony-forming units [CFUs]/bag) into whole blood (WB), apheresis PLTs (APs), and buffy coat (BC)-derived minipool PLTs. RESULTS The bacterial concentrations were higher than 106 CFUs/mL within 24 hours after spiking depending on the particular bacterial strain. PI was absolute for all of the APs performed 12 hours after inoculation, but the bacterial strains of Klebsiella pneumoniae and Bacillus cereus were not completely inactivated in WB or BC PLTs, performed 35.5 and 12 hours after inoculation, respectively. CONCLUSION The INTERCEPT PI system was not 100% effective for high concentrations of certain K. pneumoniae strains or spore-forming B. cereus. A critical observation was that the period between blood donation and inactivation needs to be minimal to enable efficient PI. In the case where PI cannot be performed immediately after preparation, a combination of a PI technology after the production of blood components with a rapid bacterial screen test on Day 4 or 5 after donation may offer a solution to further prevent the risk of bacterial transmission by transfusion. © 2015 AABB. Source

The BacT/ALERT microbial detection system (bioMerieux, Inc, Durham, NC) is in routine use in many blood centers as a prerelease test for platelet collections. Published reports document wide variation in practices and outcomes. A systematic review of the English literature was performed to describe publications assessing the use of the BacT/ALERT culture system on platelet collections as a routine screen test of more than 10. 000 platelet components. Sixteen publications report the use of confirmatory testing to substantiate initial positive culture results but use varying nomenclature to classify the results. Preanalytical and analytical variables that may affect the outcomes differ widely between centers. Incomplete description of protocol details complicates comparison between sites. Initial positive culture results range from 539 to 10. 606 per million (0.054%-1.061%) and confirmed positive from 127 to 1035 per million (0.013%-0.104%) donations. False-negative results determined by outdate culture range from 662 to 2173 per million (0.066%-0.217%) and by septic reactions from 0 to 66 per million (0%-0.007%) collections. Current culture protocols represent pragmatic compromises between optimizing analytical sensitivity and ensuring the timely availability of platelets for clinical needs. Insights into the effect of protocol variations on outcomes are generally restricted to individual sites that implement limited changes to their protocols over time. Platelet manufacturers should reassess the adequacy of their BacT/ALERT screening protocols in light of the growing international experience and provide detailed documentation of all variables that may affect culture outcomes when reporting results. We propose a framework for a standardized nomenclature for reporting of the results of BacT/ALERT screening. © 2014 Elsevier Inc. Source

Pitt T.L.,National Bacteriology Laboratory | Tidey K.,National Bacteriology Laboratory | Roy A.,National Bacteriology Laboratory | Ancliff S.,National Bacteriology Laboratory | And 2 more authors.
Cell and Tissue Banking | Year: 2014

Several antimicrobial cocktail solutions of differing composition and concentrations are widely used to decontaminate viable banked tissue allografts at different temperatures and times of exposure. We compared the efficiency of four cocktails comprising nine antimicrobials to kill suspensions of a panel of 27 strains of 13 bacterial species, and 3 Candida spp. at 4, 22 and 37 C for 24 h. All but one bacterial strains were susceptible to one or more of the agents tested individually at concentrations at least fourfold below the recommended susceptibility breakpoint minimum inhibitory concentrations for drug/species combinations. Candida lusitaniae was resistant to nystatin and amphotericin. The concentrations of several of the cocktail constituents were often greatly in excess (50-1,000-fold) of that required to inhibit the growth of susceptible strains. All cocktails were ineffective against a pan-resistant strain of Enterococcus faecium and one of the four cocktails failed to kill two strains of methicillin resistant Staphylococcus aureus. Each cocktail was most efficient at 37 C, less so at 22 C, and poorly active at 4 C. We conclude that the practice of decontamination of tissues with antimicrobials at low temperatures is not supported by in vitro susceptibility tests. © 2013 Springer Science+Business Media Dordrecht. Source

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