Phenotypic diversity and shared genomic determinants among isolates causing a large incidence of disseminated gonococcal infections in Canada
Notice bibliographique
Résumé
ABSTRACT The incidence of disseminated gonococcal infection (DGI) has remained low since the advent of antibiotics; however, a recent surge in DGI has inexplicably emerged during the past decade. In an effort to understand whether Neisseria gonorrhoeae that cause disseminated disease can be differentiated from non-invasive strains, we have performed a phenotypic and genotypic analysis on a selection of isolates obtained from invasive and uncomplicated infections in Canada. The increase in DGI was initially associated with a single antibiotic-susceptible gonococcal lineage, but later cases have been caused by diverse strains. Phenotypic analysis of a matched subset of 20 isolates obtained since 2013 found that these varied in their capacity to aggregate in suspension and in their association with serum complement proteins; however, these interactions did not discriminate between the invasive and mucosal isolates. Sequence typing of 360 Canadian isolates revealed that two variant porBa alleles are significantly associated with the DGI strains, one of these being present throughout the past decade, whereas the other emerged more recently. A PopNet-based population dynamics analysis, which instead establishes relationships based upon variance among discrete chromosomal segments, revealed that DGI isolates were restricted to distinct subpopulations within their phylogenetic distribution, implying a genetically linked potential to cause invasive disease. Consistent with this, a large number of genetic determinants are enriched in the DGI strains, making these enticing candidates to explain the increased capacity of N. gonorrhoeae to cause systemic infection and/or reduce the presentation of clinical symptoms from localized infection so that it remains untreated. IMPORTANCE The re-emergence of disseminated gonococcal infections (DGIs) has raised concern that the virulence of some strains has increased due to their acquisition of a new capacity to remain asymptomatic during uncomplicated mucosal infection and/or to invade the bloodstream and persist upon establishing colonization at distal tissue sites. The molecular epidemiology of a very large incidence of DGI in Canada, which began from a single strain but then diversified with time, provided an opportunity to understand whether the invasive isolates were either phenotypically or genotypically related. While classical phenotypic analysis did not discriminate between mucosal and invasive isolates, a population dynamics-based approach established that the DGI isolates are present within distinct subpopulations of Neisseria gonorrhoeae and reveals genetic determinants that are linked to this phenotype. This suggests that the DGI phenotype emerged multiple times independently and/or the genetic features responsible have been transmitted among the populations.
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 machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,003 |
| Études des sciences et des technologies | 0,002 | 0,001 |
| Communication savante | 0,001 | 0,000 |
| Science ouverte | 0,001 | 0,001 |
| Intégrité de la recherche | 0,000 | 0,001 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
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; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».