Development and in vitro evaluation of an Escherichia coli probiotic able to inhibit the growth of pathogenic Escherichia coli K881
Notice bibliographique
Résumé
Weaned piglets commonly suffer from gastroenteritis caused by enterotoxigenic Escherichia coli K88. Our aim was to produce E. coli strains that inhibited the growth of E. coli K88 and could be used as a probiotic against postweaning diarrhea. The inclusion criteria for the probiotics were that in addition to being able to inhibit E. coli K88, they also needed to be negative for virulence genes commonly associated with E. coli. A total of 463 E. coli isolates from the cattle rumen, cattle feces, swine feces, and soil were screened against 18 E. coli K88 clinical isolates using an agar diffusion technique. Growth inhibition of the most sensitive K88 indicator strain 2-12 occurred for 121/463 isolates: 96/358 from cattle feces, 0/33 from rumen fluid, 9/35 from swine feces, and 16/37 from soil. Of the 121 positive strains, 71/121 were negative for toxin genes (LT, STa, STb, VT1, and VT2). The 14 most inhibitory strains were screened against a range of substrates to assess the ability to utilize carbohydrates that could be included in the diet to enhance their ability to compete in the gut. Two strains, UM-2 and UM-7, were weak utilizers of starch and inulin. In vitro competition assays between the probiotic strains and E. coli K88 strain 2-12 were conducted with glucose as the only carbon source (minimal medium; MM), MM + 2% starch, or MM + 2% inulin. The UM-2 and UM-7 strains were able to outcompete strain 2-12 when glucose was the only carbon source, indicating that inhibitory activity was produced against 2-12 independent of carbon source. The UM-2 strain outcompeted strain 2-12 in assays in which potato starch or inulin was the only carbon source; the ability of 2-12 to maintain its concentrations in the culture were probably the result of cross feeding of breakdown sugars of starch and inulin that could be utilized by 2-12. In contrast, UM-7 did not grow as well as UM-2 on starch and inulin and 2-12 declined rapidly in successive cultures likely because of the lack of breakdown products of starch and inulin produced by UM-7. We conclude that probiotic E. coli without known toxins and that produce inhibitory activity against E. coli that cause postweaning diarrhea can be produced. In addition, the ability to utilize starch or inulin is an important phenotype because it likely gives the probiotic a competitive advantage in the gut.
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 | 0,003 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,001 |
| 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) | 0,000 | 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 tête enseignante, 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 ».