A rapid change in virulence gene expression during the transition from the intestinal lumen into tissue promotes systemic dissemination of Salmonella.

Bacterial pathogens causing systemic disease commonly evolve from organisms associated with localized infections but differ from their close relatives in their ability to overcome mucosal barriers by mechanisms that remain incompletely understood. Here we investigated whether acquisition of a regulatory gene, tviA, contributed to the ability of Salmonella enterica serotype Typhi to disseminate from the intestine to systemic sites of infection during typhoid fever. To study the consequences of acquiring a new regulator by horizontal gene transfer, tviA was introduced into the chromosome of S. enterica serotype Typhimurium, a closely related pathogen causing a localized gastrointestinal infection in immunocompetent individuals. TviA repressed expression of flagellin, a pathogen associated molecular pattern (PAMP), when bacteria were grown at osmotic conditions encountered in tissue, but not at higher osmolarity present in the intestinal lumen. TviA-mediated flagellin repression enabled bacteria to evade sentinel functions of human model epithelia and resulted in increased bacterial dissemination to the spleen in a chicken model. Collectively, our data point to PAMP repression as a novel pathogenic mechanism to overcome the mucosal barrier through innate immune evasion

La factibilidad de crear una agencia especializada en la organización de eventos sociales, políticos, culturales, congresos y convenciones en el municipio de Tizayuca, Hidalgo

El turismo es una actividad que destaca como estrategia, en función de los beneficios económicos y sociales que reportan para el desarrollo de nuestro país. Esta posición se ha logrado gracias a la enorme riqueza y variedad de los recursos turísticos que México tiene y sobre todo a la vocación del personal que labora en el sector, siempre preocupado por ofrecer una atención esmerada a los visitantes

Turismo

El turismo es una actividad que destaca como estrategia, en función de los beneficios económicos y sociales que reportan para el desarrollo de nuestro país. Esta posición se ha logrado gracias a la enorme riqueza y variedad de los recursos turísticos que México tiene y sobre todo a la vocación del personal que labora en el sector, siempre preocupado por ofrecer una atención esmerada a los visitantes

Caracterización y eficiencia de la fermentación en la elaboración del mezcal potosino

El maguey (Agave salmiana Otto ex Salm-Dick) es un recurso natural renovable que crece de manera silvestre en el altiplano potosino, y se ha utilizado por mucho tiempo como materia prima para la elaboración de mezcal, siendo ésta, la actual y principal forma de aprovechamiento. En la región la industria mezcalera ha sido de gran importancia económica para las poblaciones rurales, ya que el maguey es de los pocos recursos bióticos abundantes y disponibles en la región; sin embargo, el bajo costo que se paga por el recurso, enmascara la necesidad de mejorar la eficiencia de sus formas de aprovechamiento (mezcal). Particularmente la fábrica de mezcal “Laguna Seca”, representativa de la región, es de las pocas que trabajan de manera continua y a una quinta parte de su capacidad instalada. El objetivo de la presente investigación fue caracterizar el estado actual de la fermentación alcohólica en la elaboración de mezcal potosino mediante la evaluación de las diferentes variables; temperatura, pH, azúcares fermentables AF (fructosa y glucosa), densidad celular, nitrógeno y etanol en dependencia de la época del año (época lluviosa y época fría). Esta información es necesaria para entender las relación e implicación del efecto de ciertos factores en el rendimiento y la calidad del destilado; al mismo tiempo, determinante para la estandarización tanto del proceso como del producto. A la vez, conforma la base para el desarrollo de fermentaciones experimentales en laboratorio. En general la época funcional influyó significativamente en el pH y contenido de AF de los jugos frescos, y en la temperatura de la cámara de fermentación. Se carece de control de la temperatura y de la adición de nitrógeno durante la reactivación y propagación del fermento. Por lo general en la época fría, antes iniciar la fermentación los jugos se calientan con vapor si su temperatura es menor a 30 °C. La concentración ajustada de AF al inicio de la fermentación y el porcentaje de consumo de AF por las poblaciones microbianas es menor a lo registrado para tequila. El mayor consumo de AF por la población microbiana ocurrió entre las 3 y 18 h de fermentación y correspondió a la fructosa, pues la glucosa prácticamente quedó sin cambio al final de la fermentación

The Capsule-Encoding viaB Locus Reduces Intestinal Inflammation by a Salmonella Pathogenicity Island 1-Independent Mechanism▿

Salmonella enterica serotype Typhimurium elicits acute neutrophil influx in the human intestinal mucosa within 1 or 2 days after infection, resulting in inflammatory diarrhea. In contrast, no overt symptoms are observed within the first 1 or 2 weeks after infection with S. enterica serotype Typhi. Here we show that introduction of the capsule-encoding viaB locus of serotype Typhi reduced the ability of serotype Typhimurium to elicit acute intestinal inflammation in a streptomycin-pretreated mouse model. Serotype Typhimurium requires a functional invasion-associated type III secretion system (type III secretion system 1 [T3SS-1]) to elicit cecal inflammation within 48 h after infection of streptomycin-pretreated mice, and the presence of the viaB locus reduced its invasiveness for human intestinal epithelial cells in vitro. However, a reduced activity of T3SS-1 could not account for the ability of the viaB locus to attenuate cecal inflammation, because introduction of the viaB locus into an invasion-deficient serotype Typhimurium strain (invA mutant) resulted in a significant reduction of pathology and inflammatory cytokine expression in the cecum 5 days after infection of mice. We conclude that a T3SS-1-independent mechanism contributes to the ability of the viaB locus to reduce intestinal inflammation

T Cells Help To Amplify Inflammatory Responses Induced by Salmonella enterica Serotype Typhimurium in the Intestinal Mucosa▿

Salmonella enterica serotype Typhimurium causes an acute inflammatory reaction in the ceca of streptomycin-pretreated mice. We determined global changes in gene expression elicited by serotype Typhimurium in the cecal mucosa. The gene expression profile was dominated by T-cell-derived cytokines and genes whose expression is known to be induced by these cytokines. Markedly increased mRNA levels of genes encoding gamma interferon (IFN-γ), interleukin-22 (IL-22), and IL-17 were detected by quantitative real-time PCR. Furthermore, the mRNA levels of genes whose expression is induced by IFN-γ, IL-22, or IL-17, including genes encoding macrophage inflammatory protein 2 (MIP-2), inducible nitric oxide synthase (Nos2), lipocalin-2 (Lcn2), MIP-1α, MIP-1β, and keratinocyte-derived cytokine (KC), were also markedly increased. To assess the importance of T cells in orchestrating this proinflammatory gene expression profile, we depleted T cells by using a monoclonal antibody prior to investigating cecal inflammation caused by serotype Typhimurium in streptomycin-pretreated mice. Depletion of CD3+ T cells resulted in a dramatic reduction in gross pathology, a significantly reduced recruitment of neutrophils, and a marked reduction in mRNA levels of Ifn-γ, Il-22, Il-17, Nos2, Lcn2, and Kc. Our results suggest that T cells play an important role in amplifying inflammatory responses induced by serotype Typhimurium in the cecal mucosa

Genistein stimulates insulin sensitivity through gut microbiota reshaping and skeletal muscle AMPK activation in obese subjects

ObjectiveObesity is associated with metabolic abnormalities, including insulin resistance and dyslipidemias. Previous studies demonstrated that genistein intake modifies the gut microbiota in mice by selectively increasing Akkermansia muciniphila, leading to reduction of metabolic endotoxemia and insulin sensitivity. However, it is not known whether the consumption of genistein in humans with obesity could modify the gut microbiota reducing the metabolic endotoxemia and insulin sensitivity.Research design and methods45 participants with a Homeostatic Model Assessment (HOMA) index greater than 2.5 and body mass indices of ≥30 and≤40 kg/m2 were studied. Patients were randomly distributed to consume (1) placebo treatment or (2) genistein capsules (50 mg/day) for 2 months. Blood samples were taken to evaluate glucose concentration, lipid profile and serum insulin. Insulin resistance was determined by means of the HOMA for insulin resistance (HOMA-IR) index and by an oral glucose tolerance test. After 2 months, the same variables were assessed including a serum metabolomic analysis, gut microbiota, and a skeletal muscle biopsy was obtained to study the gene expression of fatty acid oxidation.ResultsIn the present study, we show that the consumption of genistein for 2 months reduced insulin resistance in subjects with obesity, accompanied by a modification of the gut microbiota taxonomy, particularly by an increase in the Verrucomicrobia phylum. In addition, subjects showed a reduction in metabolic endotoxemia and an increase in 5′-adenosine monophosphate-activated protein kinase phosphorylation and expression of genes involved in fatty acid oxidation in skeletal muscle. As a result, there was an increase in circulating metabolites of β-oxidation and ω-oxidation, acyl-carnitines and ketone bodies.ConclusionsChange in the gut microbiota was accompanied by an improvement in insulin resistance and an increase in skeletal muscle fatty acid oxidation. Therefore, genistein could be used as a part of dietary strategies to control the abnormalities associated with obesity, particularly insulin resistance; however, long-term studies are needed

Additional Information

Supplementary information includes study design and flow, gastric impedance device,  tables and plots with blood gas data, vital signs hemodynamics, laboratories, histology, and mucosal classification. </p