Enlargement of the <scp>WHO</scp> international repository for platelet transfusion‐relevant bacteria reference strains
Bibliographic record
Abstract
Background and Objectives Interventions to prevent and detect bacterial contamination of platelet concentrates (PCs) have reduced, but not eliminated the sepsis risk. Standardized bacterial strains are needed to validate detection and pathogen reduction technologies in PCs. Following the establishment of the First International Reference Repository of Platelet Transfusion‐Relevant Bacterial Reference Strains (the ‘repository’), the World Health Organization (WHO) Expert Committee on Biological Standardisation (ECBS) endorsed further repository expansion. Materials and Methods Sixteen bacterial strains, including the four repository strains, were distributed from the Paul‐Ehrlich‐Institut (PEI) to 14 laboratories in 10 countries for enumeration, identification and growth measurement on days 2, 4 and 7 after low spiking levels [10–25 colony‐forming units (CFU)/PC bag]. Spore‐forming (Bacillus cereusPEI‐B‐P‐07‐S, Bacillus thuringiensisPEI‐B‐P‐57‐S), Gram‐negative (Enterobacter cloacaePEI‐B‐P‐43, Morganella morganiiPEI‐B‐P‐74, PEI‐B‐P‐91, Proteus mirabilisPEI‐B‐P‐55, Pseudomonas fluorescensPEI‐B‐P‐77, Salmonella choleraesuisPEI‐B‐P‐78, Serratia marcescensPEI‐B‐P‐56) and Gram‐positive (Staphylococcus aureusPEI‐B‐P‐63, Streptococcus dysgalactiaePEI‐B‐P‐71, Streptococcus bovisPEI‐B‐P‐61) strains were evaluated. Results Bacterial viability was conserved after transport to the participating laboratories with one exception (M. morganiiPEI‐B‐P‐74). All other strains showed moderate‐to‐excellent growth. Bacillus cereus, B. thuringiensis, E. coli, K. pneumoniae, P. fluorescens, S. marcescens, S. aureus and S. dysgalactiae grew to >106 CFU/ml by day 2. Enterobacter cloacae, P. mirabilis, S. epidermidis, S. bovis and S. pyogenes achieved >106 CFU/ml at day 4. Growth of S. choleraesuis was lower and highly variable. Conclusion The WHO ECBS approved all bacterial strains (except M. morganiiPEI‐B‐P‐74 and S. choleraesuisPEI‐B‐P‐78) for repository enlargement. The strains were stable, suitable for spiking with low CFU numbers, and proliferation was independent of the PC donor.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.035 | 0.019 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.005 | 0.004 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.003 |
| Open science | 0.006 | 0.006 |
| Research integrity | 0.003 | 0.002 |
| Insufficient payload (model declined to judge) | 0.008 | 0.006 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".