128 research outputs found
Effect of the Escherichia coli EMO strain on experimental infection by Salmonella enterica serovar Typhimurium in gnotobiotic mice
E. coli Nissle 1917 Affects Salmonella Adhesion to Porcine Intestinal Epithelial Cells
BACKGROUND: The probiotic Escherichia coli strain Nissle 1917 (EcN) has been shown to interfere in a human in vitro model with the invasion of several bacterial pathogens into epithelial cells, but the underlying molecular mechanisms are not known. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we investigated the inhibitory effects of EcN on Salmonella Typhimurium invasion of porcine intestinal epithelial cells, focusing on EcN effects on the various stages of Salmonella infection including intracellular and extracellular Salmonella growth rates, virulence gene regulation, and adhesion. We show that EcN affects the initial Salmonella invasion steps by modulating Salmonella virulence gene regulation and Salmonella SiiE-mediated adhesion, but not extra- and intracellular Salmonella growth. However, the inhibitory activity of EcN against Salmonella invasion always correlated with EcN adhesion capacities. EcN mutants defective in the expression of F1C fimbriae and flagellae were less adherent and less inhibitory toward Salmonella invasion. Another E. coli strain expressing F1C fimbriae was also adherent to IPEC-J2 cells, and was similarly inhibitory against Salmonella invasion like EcN. CONCLUSIONS: We propose that EcN affects Salmonella adhesion through secretory components. This mechanism appears to be common to many E. coli strains, with strong adherence being a prerequisite for an effective reduction of SiiE-mediated Salmonella adhesion
Bifidobacterium Infantis 35624 Protects Against Salmonella-Induced Reductions in Digestive Enzyme Activity in Mice by Attenuation of the Host Inflammatory Response
OBJECTIVES: Salmonella-induced damage to the small intestine may decrease the villi-associated enzyme activity, causing malabsorption of nutrients and diarrhea, and thus contribute to the symptoms of infection. The objective of this study was to determine the mechanism by which different doses and durations of Salmonella infection and lipopolysaccharide (LPS) affect brush border enzyme activity in the mouse, and to determine if the probiotic Bifidobacterium longum subspecies infantis 35624 could attenuate the intestinal damage.
METHODS: BALB/c mice were challenged with Salmonella enterica serovar Typhimurium UK1 at various doses (10(2)-10(8) colony-forming unit (CFU)) and durations (10(6) CFU for 1-6 days). Mice were also treated with B. longum subsp. infantis 35624 for 2 weeks before and during a 6-day S. Typhimurium challenge (10(6) CFU), or before injection of LPS. The small intestine was assessed for morphological changes, mRNA expression of cytokines, and activity of the brush border enzymes sucrase-isomaltase, maltase, and alkaline phosphatase.
RESULTS: S. Typhimurium infection significantly reduced the activity of all brush border enzymes in a dose- and time-dependent manner (P<0.05). This also occurred following injection of LPS. Pre-treatment with B. longum subsp. infantis 35624 prevented weight loss, protected brush border enzyme activity, reduced the small intestinal damage, and inhibited the increase in interleukin (IL)-10 and IL-8 expression due to Salmonella challenge.
CONCLUSIONS: Salmonella infection reduces the small intestinal brush border enzyme activity in mice, with the level of reduction and associated weight loss increasing with dose and duration of infection. B. longum subsp. infantis 35624 treatment attenuated the effect of Salmonella infection on brush border enzyme activity and weight loss, which may be due to modulation of the host immune response
The Human Intestinal Microbiome: A New Frontier of Human Biology
To analyze the vast number and variety of microorganisms inhabiting the human intestine, emerging metagenomic technologies are extremely powerful. The intestinal microbes are taxonomically complex and constitute an ecologically dynamic community (microbiota) that has long been believed to possess a strong impact on human physiology. Furthermore, they are heavily involved in the maturation and proliferation of human intestinal cells, helping to maintain their homeostasis and can be causative of various diseases, such as inflammatory bowel disease and obesity. A simplified animal model system has provided the mechanistic basis for the molecular interactions that occur at the interface between such microbes and host intestinal epithelia. Through metagenomic analysis, it is now possible to comprehensively explore the genetic nature of the intestinal microbiome, the mutually interacting system comprising the host cells and the residing microbial community. The human microbiome project was recently launched as an international collaborative research effort to further promote this newly developing field and to pave the way to a new frontier of human biology, which will provide new strategies for the maintenance of human health
Aspects de la Corse
Hudault Claude. Aspects de la Corse. In: Le Globe. Revue genevoise de géographie, tome 102, 1962. pp. 7-8
Du jeu de fief a la propriété romaine : une critique précoce de la propriété féodale devant le parlement de Paris (1751)
Hudault Joseph. Du jeu de fief a la propriété romaine : une critique précoce de la propriété féodale devant le parlement de Paris (1751). In: Revue du Nord, tome 57, n°224, Janvier-mars 1975. pp. 120-121
Une affaire de droit ternational privé devant les juridictions de Flandre : l'affaire Beresford (1781)
Hudault Joseph. Une affaire de droit ternational privé devant les juridictions de Flandre : l'affaire Beresford (1781). In: Revue du Nord, tome 54, n°213, Avril-juin 1972. pp. 203-211
Le role de l'agriculteur dans la protection écologique de l'espace rural
La définition juridique de l'espace rural. Le rôle de l'agriculteur dans l'espace.Juriste parmi les plus prestigieux de l' Amérique latine, pétri de culture humaniste et fidele a la méthode de pensée d'inspiration romaniste dans laquelle la procédure est antérieure au droit et la loi, l'affirmation d'un principe général qu'il appartient a l'interprete de faire application a l'espece (da mihifaetum dabo tibijus), Adolfo GELSI BIDART a été l'un des premiers a mesurer l'influence du droit de l'environnement sur la substance du droit rural.C'est la raison pour laquelle 1'auteur de ces lignes dédie a la mémoire d'un ami regretté et affectionné ces quelques réflexions sur l' espace rural. Une nouvelle fois, il convient d' attirer l'attention des spécialistes du droit rural sur la nécessité de définir 1'espace rural de fa<;on a lui donner un statut juridique.</p
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