pVir and Bloody Diarrhea in<i>Campylobacter jejuni</i>Enteritis
Notice bibliographique
Résumé
The plasmid pVir may play a role in the virulence of Campylobacter jejuni, a leading cause of bacterial gastroenteritis.The pVir plasmid was identified in 17% of 104 C. jejuni clinical isolates studied and was significantly associated with the occurrence of blood in patient stool, a marker of invasive infection.The pVir plasmid was not associated with greater occurrence of diarrhea, fever, pain, vomiting, or need for patient hospitalization.Isolates containing pVir were also associated with the presence of a tetracycline-resistance plasmid, but pVir did not transfer with tetracycline-resistance plasmids to recipient strains of C. jejuni.The association of pVir and bloody stool suggests that pVir may be clinically relevant in C. jejuni infections.C ampylobacter jejuni is a major foodborne pathogen and a leading cause of bacterial gastroenteritis (1,2).Infection with C. jejuni can result in a wide array of clinical symptoms, including diarrhea, fever, abdominal pain, and vomiting, as well as bloody stool with severe invasive infection (3).Various virulence factors, which allow for adherence, colonization, and invasion of the intestinal epithelium, have been proposed to contribute to the pathogenesis of C. jejuni (4).Potential virulence components include flagella (5,6), invasion proteins (7), and toxins (8,9).Although the genome of C. jejuni has been sequenced (10), its mechanisms of pathogenicity remain poorly understood (11).A number of bacterial enteric pathogens contain plasmids that contribute to pathogenesis, including Shigella sp.(12), Salmonella sp.(13), and enteropathogenic Escherichia coli (14).No evidence was seen for the involvement of plasmids in the virulence of C. jejuni until Bacon et al. (15) identified plasmid pVir in strain 81-176.pVir is an ≈37.5-kbplasmid that contains components of a type IV secretion system (T4SS) (15,16) known to be important for the virulence of a number of major bacterial pathogens (17).Bacon et al. (15) suggested that the pVir plasmid is important in vitro for both adherence and invasion of intestinal epithelial cells in culture.In a survey of fresh clinical isolates of C. jejuni from Thailand, 10% (n = 58) contained pVir (15).C. jejuni gastroenteritis is primarily self-limiting and is usually treated by supportive therapy (fluid and electrolyte replacement) (3).Erythromycin is the drug of choice for treating severe clinical infections with C. jejuni (18), and fortunately the prevalence of erythromycin resistance has remained low (19).Worldwide, tetracycline resistance in C. jejuni is high: 56% in Canada (20) and up to 95% in Thailand (21).In Alberta, Canada, only 8.6% of human clinical isolates were tetracycline-resistant in 1981 (22).In C. jejuni, tetracycline resistance is primarily mediated by plasmids that carry the tet(O) gene (23,24).The Tet(O) protein binds to the bacterial ribosome and displaces tetracycline (25,26).The aim of this study was to investigate the prevalence of the pVir plasmid in C. jejuni isolated from clinical specimens in Alberta and the relationship of pVir to the clinical expression of the disease in gastroenteritis. Materials and Methods Source of C. jejuni IsolatesWe obtained a random sample of 104 human isolates of C. jejuni (fresh and frozen at -70°C in double-strength skim milk) cultured from stool samples from 1999 to 2002 at the University of Alberta Hospital and Provincial Laboratory for Public Health (Microbiology) in Edmonton, Alberta, Canada, for this study.All stool specimens were routinely cultured for enteric pathogens tested according to standard laboratory protocols.Most C. jejuni isolates were from northern Alberta and represented ≈10% pVir and Bloody Diarrhea in Campylobacter jejuni Enteritis
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 | 0,002 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| 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 ».