Notice bibliographique
Résumé
Background: Cutibacterium acnes, an anaerobic, aerotolerant skin microflora bacterium, is a predominant contaminant of platelet concentrates (PCs).At Canadian Blood Services, approximately 35% of PCs with positive results for bacterial screening are transfused, of which 97% carry C. acnes.Retrospective studies performed by other blood suppliers report similar trends, with C. acnes related to mild transfusion reactions.However, it is unknown whether C. acnes can cause delayed infections in transfused patients.This is pertinent as C. acnes causes serious chronic infections linked to formation of surface-attached aggregates (biofilms) and exacerbation of inflammation.Previous work in our laboratory has demonstrated that the PC milieu enhances the expression of virulence genes in transfusion-relevant bacteria like Staphylococcus aureus and Staphylococcus epidermidis.Additionally, we have employed a nematode killing assay to demonstrate the enhanced pathogenicity of S. epidermidis grown in PCs.In this study, modulation of C. acnes virulence in PCs has been evaluated with the Bombyx mori (silkworm) model, which has been used to study clinically relevant bacterial pathogens.Aims: To determine if C. acnes gains heightened virulence in PCs using the invertebrate Bombyx mori model.Methods: Transfusion-relevant C. acnes and S. aureus PC isolates were used in this study, where S. aureus served as a positive control for virulence.The silkworm virulence assay entails the inoculation of the haemocoel of the larvae with a sample of interest and an assessment of survival over 72 h.The lethal concentration of 50% (LC50) for the assay was determined using varying concentrations of bacterial inocula prepared in insect saline (0.6% NaCl).Buffy coat PCs and culture media were inoculated with C. acnes and S. aureus and maintained under PC storage conditions for 5 days.Bacterial samples from media were centrifuged and resuspended in insect saline, while samples obtained from PCs were used without further manipulation.Sample bacterial concentrations were normalized to reflect LC50 values, each sample was tested using 10 larvae, and experiments were repeated three times. Results:The LC50 for C. acnes and S. aureus was determined to be $1.27 10 8 and 3.42 10 6 colony-forming unit per larvae, respectively.Higher survival rates of $37 15% were observed for larvae injected with C. acnes derived from PCs when compared to those derived from media ( p = 0.009).In contrast, larvae injected with S. aureus derived from PCs displayed reduced survival $30 20% when compared to media ( p = 0.27).Though variability was observed within the three replicates for each bacterium tested due to PC donor differences, the survival trends were consistent across the replicates.Summary/Conclusions: The data obtained indicate that the PC milieu influences the virulence of bacterial contaminants in a species-dependent manner.Unexpectedly, C. acnes virulence, as assessed by the silkworm assay, is not heightened in PCs but rather diminished, potentially caused by platelet aggregation preventing bacterial interaction with the host.These findings could also explain the low incidence of septic transfusion reactions despite the high level of transfusions with C. acnes-contaminated PCs.Next steps will focus on determining changes in expression of genes involved in C. acnes virulence and the silkworm immune response, to assess whether C. acnes in PCs could be primed to cause chronic infections like infective endocarditis or cause an enhanced inflammatory response in transfused patients.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,001 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,001 | 0,001 |
| Méta-épidémiologie (sens large) | 0,001 | 0,001 |
| Bibliométrie | 0,001 | 0,001 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,001 | 0,000 |
| Intégrité de la recherche | 0,001 | 0,002 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,018 | 0,042 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; les deux têtes enseignantes s’accordent sur ce qui est montré ici.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».