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1.
Int. microbiol ; 22(3): 325-336, sept. 2019. mapas, graf, tab
Artigo em Inglês | IBECS | ID: ibc-184839

RESUMO

Soil microbial communities are an important component of biological diversity and terrestrial ecosystems which is responsible for processes such as decomposition, mineralization of nutrients, and accumulation of organic matter. One of the factors that provide information on the mechanisms regulating biodiversity is spatial scaling. We characterized the microbial communities using 16S rRNA gene sequences from DNA isolated from halite at various locations and correlated these to geographic distance in the Uyuni salt flat (Bolivia). Sequences from each site were analyzed to determine any spatial patterns of diversity, as well as to describe the microbial communities. Results suggest that different taxa are able to disperse over Uyuni's surface crust regardless of distance. As expected, ubiquitous taxa included members of Halobacteriaceae such as Haloarcula, Halorubrum, Halorhabdus, Halolamina, and halophilic bacteria Salinibacter, Halorhodospira, and unclassified members of the Gammaproteobacteria. Archaeal communities were homogeneous across the salt flat. In contrast, bacterial communities present strong local variations which could be attributed to external factors. Likely sources for these variations are the Rio Grande river influent in the south shore and the Tunupa volcano influencing the northern area


No disponible


Assuntos
Microbiologia do Solo , Bactérias/classificação , Biota , Archaea/classificação , RNA Ribossômico 16S/genética , Bolívia , Bactérias/genética , Archaea/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , DNA Arqueal/química , DNA Arqueal/genética , Metagenômica , Filogenia
2.
Int. microbiol ; 22(2): 181-189, jun. 2019. graf, tab
Artigo em Inglês | IBECS | ID: ibc-184825

RESUMO

This study aimed to analyze the bacterial diversity in carwash effluents and to determine their potential for use in microbial degradation of environmental contaminants. Nine carwash effluent samples were collected for physicochemical and bacterial community diversity analysis using multi-digital probes and 16S rRNA gene amplicon sequencing respectively. The pH of all effluent samples was neutral to slightly alkaline. Oil and grease concentrations ranged from 15.3 to 49.7 mg/L. 16S gene amplicon sequencing of the nine samples produced 45,934-sequence reads, which translated to 13 bacterial phyla, 26 classes, and 43 genera. The most dominant phyla were Proteobacteria, Bacteroidetes, Firmicutes, and Fusobacteria. Canonical correspondence analysis (CCA) showed that the distribution of the phyla Proteobacteria, Bacteroidetes, Acidobacteria, and Verrucomicrobia was influenced by the presence of oil and grease, total petroleum hydrocarbons-gasoline range organics (GRO-TPH), and metals species (Pb, Cu, and Zn). The dominant bacterial genera found in the present study were previously proven to biodegrade hydrocarbons, and their presence in carwash effluents could bode well for in situ natural bioremediation of these contaminated sites


No disponible


Assuntos
Bactérias/genética , Biota , DNA Bacteriano/genética , DNA Ribossômico/genética , Hidrocarbonetos/análise , RNA Ribossômico 16S/genética , Poluentes Químicos da Água/análise , Bactérias/classificação , Análise por Conglomerados , DNA Bacteriano/química , DNA Ribossômico/química , Concentração de Íons de Hidrogênio , Óleos/análise , Filogenia , Metais/análise
3.
Int. microbiol ; 19(3): 161-173, sept. 2016. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-162893

RESUMO

A previously established chronosequence from Pia Glacier forefield in Tierra del Fuego (Chile) containing soils of different ages (from bare soils to forest ones) is analyzed. We used this chronosequence as framework to postulate that microbial successional development would be accompanied by changes in functionality. To test this, the GeoChip functional microarray was used to identify diversity of genes involved in microbial carbon and nitrogen metabolism, as well as other genes related to microbial stress response and biotic interactions. Changes in putative functionality generally reflected succession-related taxonomic composition of soil microbiota. Major shifts in carbon fixation and catabolism were observed, as well as major changes in nitrogen metabolism. At initial microbial dominated succession stages, microorganisms could be mainly involved in pathways that help to increase nutrient availability, while more complex microbial transformations such as denitrification and methanogenesis, and later degradation of complex organic substrates, could be more prevalent at vegetated successional states. Shifts in virus populations broadly reflected changes in microbial diversity. Conversely, stress response pathways appeared relatively well conserved for communities along the entire chronosequence. We conclude that nutrient utilization is likely the major driver of microbial succession in these soils (AU)


No disponible


Assuntos
Microbiologia do Solo , Ecossistema Glacial/análise , Contagem de Colônia Microbiana/métodos , Estresse Fisiológico , Resistência Microbiana a Medicamentos , Viabilidade Microbiana , Biota/fisiologia
4.
Int. microbiol ; 19(2): 81-90, jun. 2016. ilus
Artigo em Inglês | IBECS | ID: ibc-158062

RESUMO

All living organisms have acquired the outstanding ability to overcome the limitations imposed by changeable environments through the gain of genetic traits over years of evolution and the tendency of individuals to associate in communities. The complementation of a singular weakness, the deployment of reinforcement for the good of the community, the better use of resources, or effective defense against external aggression are advantages gained by this communal behavior. Communication has been the cohesive element prompting the global responses that promote efficiency in two features of any community: specialization in differentiated labor and the spatio-temporal organization of the environment. These principles illustrate that what we call human ecology also applies to the cellular world and is exemplified in eukaryotic organisms, where sophisticated cell-to-cell communication networks coordinate cell differentiation and the specialization of multiple tissues consisting of numerous cells embedded in a multifunctional extracellular matrix. This sophisticated molecular machinery appears, however, to be invented by the ‘simple’ but still fascinating bacteria. What I will try to expand in the following sections are notions of how ‘single prokaryotic cells’ organize a multicellular community (AU)


No disponible


Assuntos
Biota/fisiologia , Células Procarióticas/microbiologia , Diferenciação Celular/fisiologia , Fenômenos Fisiológicos Bacterianos , Matriz Extracelular/ultraestrutura , Biofilmes/crescimento & desenvolvimento
5.
Int. microbiol ; 19(1): 1-13, mar. 2016. ilus
Artigo em Inglês | IBECS | ID: ibc-157079

RESUMO

The first part of this review (‘Monitoring of airborne biological particles in outdoor atmosphere. Part 1: Importance, variability and ratios’) describes the current knowledge on the major biological particles present in the air regarding their global distribution, concentrations, ratios and influence of meteorological factors in an attempt to provide a framework for monitoring their biodiversity and variability in such a singular environment as the atmosphere. Viruses, bacteria, fungi, pollen and fragments thereof are the most abundant microscopic biological particles in the air outdoors. Some of them can cause allergy and severe diseases in humans, other animals and plants, with the subsequent economic impact. Despite the harsh conditions, they can be found from land and sea surfaces to beyond the troposphere and have been proposed to play a role also in weather conditions and climate change by acting as nucleation particles and inducing water vapour condensation. In regards to their global distribution, marine environments act mostly as a source for bacteria while continents additionally provide fungal and pollen elements. Within terrestrial environments, their abundances and diversity seem to be influenced by the land-use type (rural, urban, coastal) and their particularities. Temporal variability has been observed for all these organisms, mostly triggered by global changes in temperature, relative humidity, et cetera. Local fluctuations in meteorological factors may also result in pronounced changes in the airbiota. Although biological particles can be transported several hundreds of meters from the original source, and even intercontinentally, the time and final distance travelled are strongly influenced by factors such as wind speed and direction (AU)


No disponible


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Poluentes Biológicos , 32418/análise , Contaminação Biológica/análise , Genômica/métodos , Contagem de Partículas/métodos , Material Particulado/análise , Biota , Aerossóis/análise , Mudança Climática
6.
Rev. iberoam. micol ; 33(1): 7-12, ene.-mar. 2016. tab, ilus
Artigo em Espanhol | IBECS | ID: ibc-149368

RESUMO

Antecedentes. El suelo es el reservorio natural de hongos queratinofílicos que constituyen un pequeño pero importante grupo de hongos filamentosos; algunos de ellos se desarrollan típicamente sobre tejidos queratinizados de animales vivos. Hay numerosas especies de geohongos saprobios con habilidades queratolíticas reconocidas y son varios los trabajos realizados con el fin de vincular su presencia a la posible enfermedad humana. Objetivos. Conocer la biota de geohongos en general y la de aquellos queratolíticos en particular en suelos de dos parques públicos. Métodos. Las muestras se tomaron de suelos de dos parques públicos de la ciudad de Corrientes, Argentina, durante dos estaciones del año. Para el aislamiento de los hongos se usaron las técnicas del anzuelo queratínico y la de las diluciones. Resultados. Mediante la técnica del anzuelo se aislaron 170 cepas que se clasificaron en 17 géneros y 21 especies, entre las que merece destacar la presencia de Microsporum canis. El índice de Shannon de hongos queratolíticos fue medio, siendo en otoño (2,27) más alto que en primavera (1,92). Con la técnica de diluciones seriadas se obtuvieron 278 cepas que se clasificaron en 33 géneros y 71 especies; el índice de Shannon fue más alto en otoño (3,9) que en primavera (3,5). Conclusiones. Los suelos estudiados presentan condiciones particularmente favorables para la supervivencia de geohongos patógenos y oportunistas para el hombre y los animales (AU)


Background. The soil is a natural reservoir of keratinophilic fungi, which are a small but important group of filamentous fungi, some of which typically develop on keratinized tissues of living animals. There are numerous species of saprophytic fungi with recognized keratinophilic abilities, and several studies have been undertaken in order to link their presence to possible human disease. Aims. To know the biota of geophilic fungi in general and of keratinophilic fungi particularly in soils from two public parks. Methods. Soil samples from two public parks of Corrientes city, Argentina, were studied during two seasons, using the hook technique and serial dilutions for fungal isolation. Results. Using the hook technique, 170 isolates were classified into 17 genera and 21 species, among which it is worth mentioning the presence of Microsporum canis. Shannon index for keratinophilic fungi in autumn was 2.27, and 1.92 in spring. By means of the serial dilutions technique, 278 fungi isolated were identified into 33 genera and 71 species. Shannon index in autumn was 3.9, and 3.5 in spring. Conclusions. The soils studied have particularly favorable conditions for the survival of pathogens and opportunistic geophilic fungi for humans and animals (AU)


Assuntos
Fungos/classificação , Fungos/isolamento & purificação , Fungos/patogenicidade , Microbiologia do Solo , Zonas de Recreação/análise , Áreas Verdes/análise , Microsporum/isolamento & purificação , Queratinas/isolamento & purificação , Biota , Aspergillus/isolamento & purificação , Aspergillus/patogenicidade , Aspergillus niger/isolamento & purificação , Aspergillus niger/patogenicidade
7.
Rev. iberoam. micol ; 31(3): 182-187, jul.-sept. 2014.
Artigo em Espanhol | IBECS | ID: ibc-127628

RESUMO

Antecedentes. La humedad relativa y las temperaturas altas existentes en los países tropicales propician condiciones favorables para el desarrollo de hongos que pueden ser perjudiciales no solo para la salud humana, sino también para los soportes documentales. Objetivos. Determinar la concentración fúngica en el aire de dos depósitos del Archivo Nacional de la República de Cuba y la micobiota depositada sobre diferentes soportes fotográficos y mapas conservados en estos depósitos, así como realizar la caracterización taxonómica de los hongos aislados. Métodos. El muestreo del aire se realizó con un método de sedimentación, y los soportes (6 fotos y 7 mapas) se analizaron empleando hisopos estériles humedecidos. Resultados. El género que predominó fue Cladosporium, seguido por los géneros Aspergillus y Penicillium. De todas las fotos y los mapas se aislaron hongos filamentosos y solo de una técnica fotográfica y un mapa se aislaron levaduras. Se identificaron varias especies de los géneros Aspergillus y Penicillium, pero Aspergillus niger y Aspergillus flavus fueron las especies predominantes. Se aislaron cepas de levaduras de los géneros Candida y Rhodotorula. Conclusiones. La concentración fúngica del aire puso en evidencia que los ambientes no están contaminados. De 26 hongos filamentosos aislados, solamente 5 se detectaron tanto en el aire de los depósitos como sobre uno o más de los soportes documentales analizados, lo que representa un 19,3%. Esto demuestra que existe una relación ecológica baja entre los hongos encontrados en el aire y los que se aislaron de los soportes analizados (AU)


Background. The high relative humidity and temperatures in tropical countries create favorable conditions for development of fungi that are not only a risk to human health but they can also colonize documentary support. Aims. To study the concentration of the airborne fungi in two repositories of the National Archives of the Republic of Cuba, the mycobiota deposited on different photographic supports and maps preserved in these repositories, and to determine the taxonomic characterization of the fungi isolated. Methods. The air sampling was performed using a sedimentation method, and the supports (6 pictures and 7 maps) were analyzed using moistened sterile swabs. Results. The Cladosporium genus was predominant, followed by Aspergillus and Penicillium genera. Filamentous fungi were isolated in all the photos and maps, and yeasts were only isolated from a photographic supports and a map. We identified several species of Aspergillus and Penicillium genera, but Aspergillus niger and Aspergillus flavus predominated. Candida and Rhodotorula were the yeast genera isolated. Conclusions. The fungal concentration of the air demonstrated that the environments were not contaminated. From the 26 species of filamentous fungi isolated only 5 were detected in the indoor air of the repositories and on one or more of the document supports analyzed (representing a 19.3%). This shows that there is a low ecological relationship between the fungi detected in the indoor air and those that were isolated from the supports studied (AU)


Assuntos
Humanos , Masculino , Feminino , Arquivamento , Poluição Ambiental/efeitos adversos , Poluição Ambiental/análise , Poluição Ambiental/prevenção & controle , Fungos/isolamento & purificação , Micoses/microbiologia , Microbiologia do Ar , Biota , 24966/análise , 24966/métodos , Sedimentação/métodos , Cladosporium/isolamento & purificação , Aspergillus/isolamento & purificação , Fungos/patogenicidade , Aspergillus/patogenicidade , Penicillium/patogenicidade , Candida/isolamento & purificação , Candida/patogenicidade , Rhodotorula/isolamento & purificação , Rhodotorula/patogenicidade
10.
Int. microbiol ; 16(3): 133-143, sept. 2013. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-118204

RESUMO

Symbiogenesis is the result of the permanent coexistence of various bionts to form the holobiont (namely, the host and its microbiota). The holobiome is the sum total of the component genomes in a eukaryotic organism; it comprises the genome of an individual member of a given taxon (the host genome) and the microbiome (the genomes of the symbiotic microbiota). The latter is made up of the genes of a variety of microbial communities that persist over time and are not eliminated by natural selection. Therefore, the holobiome can also be considered as the genomic reflection of the complex network of symbiotic interactions that link an individual member of a given taxon with its associated microbiome. Eukaryotic individuals can be analyzed as coevolved, tightly integrated, prokaryotic communities; in this view, natural selection acts on the holobiont as if it were an integrated unit. The best studied holobionts are those that emerged from symbioses involving insects. The presence of symbiotic associations throughout most of the evolutionary history of insects suggests that they were a driving force in the diversification of this group. Support for the evolutionary importance of symbiogenesis comes from the observation that the gradual passage from an ancestral to a descendant species by the accumulation of random mutations has not been demonstrated in the field, nor in the laboratory, nor in the fossil record. Instead, symbiogenesis expands the view of the point-mutation-only as the unique mechanisms of evolution and offers an explanation for the discontinuities in the fossil record («punctuated equilibrium»). As such, it challenges conventional paradigms in biology. This review describes the relationships between xylophagous insects and their microbiota in an attempt to understand the characteristics that have determined bacterial fidelity over generations and throughout evolutionary history (AU)


No disponible


Assuntos
Animais , Simbiose/fisiologia , Biota , Evolução Molecular , Insetos/microbiologia , Ecossistema
11.
Rev. toxicol ; 29(2): 84-89, jul.-dic. 2012. tab
Artigo em Espanhol | IBECS | ID: ibc-126218

RESUMO

El Modelo del Ligando Biótico (BLM) es un modelo basado en el equilibrio químico. Incorpora el efecto de las características físico-químicas del agua en la biodisponibilidad y toxicidad de los metales sobre la biota acuática. Ha sido desarrollado para cuatro metales (Cu, Zn, Ag, Cd), dos especies de peces y tres de dáfnidos. Se asume que sus predicciones podrían ser extrapoladas a especies similares. En este estudio, se evaluó una posible extrapolación inter-especifica (peces) del BLM desarrollado para el zinc en agua del río Pilcomayo. Se llevó a cabo un ensayo de toxicidad aguda del zinc en el pez nativo Cnesterodon decemmaculatus. Las concentraciones de zinc disuelto aplicadas fueron: 0,13; 3,74; 9,2; 21,6 y 26,4 mg Zn L-1. La concentración letal media del zinc (CL50 96-h) calculada para C. decemmaculatus fue 22,6 mg Zn L-1 (17,5 - 27,6) y la predicha por el BLM para Pimephales promelas en el agua experimental fue 1,71 mg L-1. Las concentraciones de zinc medidas excedían la solubilidad del metal lo que produjo la precipitación del mismo, derivando en una 96-h CL50 que muy probablemente incluyó tanto especies de zinc disueltas como precipitadas. Sin embargo, las estimaciones de la especiación mostraron que la especie química del zinc más abundante en todos los tratamientos fue el ion libre. La mayor proporción de zinc en su forma iónica libre explicaría el bajo efecto protector de la elevada dureza del agua experimental. La diferencia entre la toxicidad del zinc observada y la predicha por el BLM podría deberse a la combinación de inexactitud en las mediciones de zinc disuelto y una menor sensibilidad de la especie experimental a la presencia de elevadas concentraciones de zinc (AU)


The Biotic Ligand Model (BLM) is a chemical equilibrium-based model that incorporates the effect of physicochemical water characteristics on the bioavailability and toxicity of metals to aquatic biota. It was developed for four metals (Cu, Zn, Ag and Cd), two fish species and three daphnids. It is assumed that its predictions can be extrapolated between similar species. In this study, a cross-fish-species extrapolation of the BLM developed for zinc (Zn-BLM) was assessed in Pilcomayo River water. An acute zinc toxicity test was performed to assess zinc toxicity to the local fish Cnesterodon decemmaculatus. The dissolved zinc concentrations tested were:3.74;9.2; 21.6 and 26.4 mg Zn L-1. The median letal zinc concentration (96-h Zn LC50) calculated for C. decemmaculatus was 22.6 mg Zn L-1 (17.5-27.6) and the predicted by Zn-BLM for Pimephales promelas in the test water was 1.71 mg L−1. Zinc concentrations measured exceeded zinc solubility causing metal precipitation which derived in a 96-h LC50 that most probably included both dissolved and precipitated zinc species. Nevertheless, speciation estimates showed that the more abundant zinc species in each treatment was the free ion. This higher proportion of zinc in its free ionic form would explain the low protective effect exerted by elevated water hardness. The difference between the observed zinc toxicity to C. decemmaculatus and the predicted by BLM for P. promelas may be due to the combination of inaccuracy in zinc dissolved measurements and a lower sensitivity of C. decemmaculatus to zinc exposure (AU)


Assuntos
Metais/toxicidade , Disponibilidade Biológica , Biota , Zinco/toxicidade , Compostos de Zinco , Fatores Bióticos , Peixes/microbiologia , Água do Mar/química , Água do Mar/microbiologia
12.
Nutr. hosp ; 27(5): 1408-1414, sept.-oct. 2012. ilus
Artigo em Inglês | IBECS | ID: ibc-110167

RESUMO

Introduction: Advances in tools for molecular investigations have allowed deeper understanding of how microbes can influence host physiology. A very interesting field of research that has gained attention recently is the possible role of gut microbiota in the development of obesity and metabolic disorders. Objective: The aim of this review is to discuss mechanisms that explain the influence of gut microbiota on host metabolism. Results and discussion: The gut microbiota is important for normal physiology of the host. However, differences in their composition may have different impacts on host metabolism. It has been shown that obese and lean subjects present different microbiota composition profile. These differences in microbiota composition may contribute to weight imbalance and impaired metabolism. The evidences from animal models suggest that it is possible that the microbiota of obese subjects has higher capacity to harvest energy from the diet providing substrates that can activate lipogenic pathways. In addition, microorganisms can also influence the activity of lipoprotein lipase interfering in the accumulation of triglycerides in the adipose tissue. The interaction of gut microbiota with the endocannabinoid system provides a route through which intestinal permeability can be altered. Increased intestinal permeability allows the entrance of endotoxins to the circulation, which are related to the induction of inflammation and insulin resistance in mice. The impact of the proposed mechanisms for humans still needs further investigations. However, the fact that gut microbiota can be modulated through dietary components highlights the importance to study how fatty acids, carbohydrates, micronutrients, prebiotics, and probiotics can influence gut microbiota composition and the management of obesity. Gut microbiota seems to be an important and promising target in the prevention and treatment of obesity and its related metabolic disturbances in future studies and in clinical practice (AU)


Introducción: Los avances en herramientas para la investigación molecular han permitido una mayor comprensión de cómo los microbios pueden influir en la fisiología del huésped. Un campo de investigación muy interesante que se ha llamado la atención recientemente es el posible papel de la microbiota intestinal en el desarrollo de la obesidad y de los trastornos metabólicos. Objetivos: El objetivo de esta revisión es discutir los mecanismos que explican la influencia de la microbiota intestinal en el metabolismo del huésped. Resultados y discusión: La microbiota intestinal es importante para la fisiología normal del huésped. Sin embargo, las diferencias en su composición pueden tener efectos diferentes sobre el metabolismo del huésped. Se ha demostrado que las personas obesas y delgadas tienen un perfil de composición diferente de la microbiota. Estas diferencias en la composición de la microbiota pueden contribuir a un desequilibrio de peso y alteración del metabolismo. Las evidencias de los modelos animales sugieren que es posible que la microbiota de los sujetos obesos tienen una mayor capacidad para captar energía de la dieta proporcionando sustratos que pueden activar las vías lipogénicas. Además, los microorganismos también pueden influir en la actividad de la lipoproteína lipasa lo que interfiere con la acumulación de triglicéridos en el tejido adiposo. La interacción de la microbiota intestinal con el sistema endocannabinoide proporciona una ruta a través del cual puede alterar la permeabilidad intestinal. Aumento de la permeabilidad intestinal permite la entrada de la circulación de endotoxinas, que están relacionados con la inducción de la inflamación y la resistencia a la insulina en los ratones. El impacto de los mecanismos propuestos para los seres humanos todavía necesita uma mayor investigación. Sin embargo, el hecho de que la microbiota intestinal puede ser modulada por componentes de la dieta refuerza la importancia de estudiar cómo los ácidos grasos, hidratos de carbono, micronutrientes, prebióticos y probióticos pueden influir en la composición de la microbiota intestinal y el desarrollo de la obesidad. La microbiota intestinal parece ser un objetivo importante y prometedor en la prevención y el tratamiento de la obesidad y trastornos metabólicos relacionados en la investigación futura y la práctica clínica (AU)


Assuntos
Humanos , Obesidade/fisiopatologia , Biota , Intestinos/microbiologia , Inflamação/fisiopatologia , Fatores Bióticos , Endocanabinoides , Ácidos Graxos/metabolismo , Carboidratos da Dieta/metabolismo , Micronutrientes/metabolismo , Prebióticos/análise , Probióticos/metabolismo
13.
Nutr. hosp ; 27(2): 382-390, mar.-abr. 2012.
Artigo em Inglês | IBECS | ID: ibc-103416

RESUMO

Introduction: The reduction in the capacity of insulin to reach its biological effects can lead to a chronic hyperglycemia and hyperinsulinemia, assuming an important role in the pathogenesis of metabolic disorders associated to obesity and diabetes. Insulin resistance is associated to chronic subclinical inflammation, which in part can be mediated by increased plasmatic lipopolysaccharide levels, an endotoxin derived from the membrane of gramnegative bacteria that mainly reside in the gut. Objectives: The aim of this review study is to describe the molecular mechanisms involved in the pathogenesis of insulin resistance due to metabolic endotoxemia and of its connection to obesity and diabetes. Results and discussion: Lipopolysaccharide present in the intestinal lumen can reach the circulatory system causing metabolic endotoxemia. When lipopolysaccharide binds to Toll-like receptor 4, inflammation is activated, changing several stages of insulin signaling. It has been shown that chronic exposure to this endotoxin may contribute to weight gain and type 2 diabetes mellitus manifestation. Obese and diabetic people have increased plasmatic lipopolysaccharide levels. The increase in the number of gram-negative bacteria on gut microbiota, the reduction on gut mucosal integrity, and the consumption of high-fat diets increase the plasmatic lipopolysaccharide levels. Therefore, the type of diet consumed may modulate the composition of gut microbiota and improve gut mucosal integrity, decreasing the occurrence of endotoxemia and its postprandial inflammatory effects, leading to adequate insulin signaling. However, there are very few studies that evaluated the influence of nutrients and/or specific food types on metabolic endotoxemia (AU)


Introducción: La reducción de la capacidad de de la insulina para alcanzar sus efectos biológicos puede inducir a un proceso crónico de la hiperglucemia y la hiperinsulinemia, asumiendo un rol de importancia en la patogénesis de las alteraciones metabólicas relacionadas con la obesidad y la diabetes. Esta resistencia a la insulina se conecta a la inflamación crónica subclínica que, en parte, podría estar mediado por el aumento de los niveles plasmáticos de lipopolisacárido, una endotoxina derivada de la membrana de las bactérias gram-negativas que reside principalmente en el intestino. Objetivos: El objetivo de esta revisión es describir los mecanismos moleculares implicados en la patogénesis de la resistencia a la insulina que surgen a partir de la endotoxemia metabólica y la conexión con la obesidad y la diabetes. Resultados y discusión: Lipopolisacárido presente en el lumen intestinal podría tener acceso al sistema circulatorio, generando un cuadro de endotoxemia metabólica. Cuando se conecta a los receptors Toll-like 4, lipopolisacárido activa vías que conducen a la inflamación, alterar la señalización de insulina en varios pasos. Los estudios han demostrado que la exposición crónica a la endotoxina podría contribuir al aumento de peso y la manifestación de la diabetes mellitus tipo 2. Las personas obesas y diabéticas se han incrementado los niveles plasmáticos de lipopolisacárido. El aumento del número de bacterias gramnegativas en la microbiota intestinal, la disminución de la integridad de la mucosa intestinal, y el consumo de dietas ricas en grasa aumentar los niveles plasmáticos de lipopolisacárido. En este contexto, el tipo de dieta ingerida podría modular la composición de la microbiota y mejorar la integridad de la mucosa intestinal, disminuyendo la aparición de endotoxemia y sus efectos inflamatorios posprandial, promoviendo así la señalización de la insulina. Sin embargo, los estudios de lo que se acerca de la influencia de los nutrientes y/o alimentos específicos en la endotoxemia metabólica son aún insuficientes (AU)


Assuntos
Humanos , Endotoxemia/fisiopatologia , Resistência à Insulina/fisiologia , Biota , Lipopolissacarídeos/efeitos adversos , Obesidade/fisiopatologia , Diabetes Mellitus/fisiopatologia , Inflamação/fisiopatologia
14.
Nutr. hosp ; 27(1): 123-129, ene.-feb. 2012. tab
Artigo em Inglês | IBECS | ID: ibc-104861

RESUMO

Introduction: Prebiotics positively affect gut microbiota composition, thus improving gut function. These properties may be useful for the treatment of constipation. Objectives: This study assessed the tolerance and effectiveness of a prebiotic inulin/partially hydrolyzed guargum mixture (I-PHGG) for the treatment of constipation in females, as well as its influence on the composition of intestinal microbiota and production of short chain fattyacids. Methods: Our study enrolled 60 constipated female health worker volunteers. Participants reported less than3 bowel movements per week. Volunteers were randomized to treatment with prebiotic or placebo. Treatment consisted of 3 weeks supplementation with 15 g/d IPHGG (fiber group) or maltodextrin (placebo group).Abdominal discomfort, flatulence, stool consistency, and bowel movements were evaluated by a recorded daily questionnaire and a weekly interview. Changes in fecal bacterial population and short chain fatty acids were assessed by real-time PCR and gas chromatography, respectively. Results: There was an increased frequency of weekly bowel movements and patient satisfaction in both the fiber and placebo groups with no significant differences. Total Clostridium sp significantly decreased in the fibergroup (p = 0.046) and increased in the placebo group (p =0.047). There were no changes in fecal short chain fatty acid profile. Conclusions: Consumption of I-PHGG produced clinical results comparable to placebo in constipated females, but had additional protective effects on gut microbiota by decreasing the amount of pathological bacteria of the Clostridium genera (AU)


Introducción: Los prebióticos influyen positivamente en la composición de la microbiota intestinal, mejorando así la función intestinal. Estas propiedades pueden ser útiles para el tratamiento del estreñimiento. Objetivos: Este estudio evaluó la tolerancia y la eficacia de una mezcla de prebiótico inulina con la goma guar parcialmente hidrolizada (I-PHGG) para el tratamiento de mujeres con estreñimiento, así como su influencia en la composición de la microbiota intestinal y la producción de ácidos grasos de cadena corta. Métodos: Nuestro estudio contó con la participación de60 mujeres voluntarias con estreñimiento y profesionales de la salud. Las participantes informaron tener menos de tres evacuaciones por semana y fueron asignadas aleatoriamente a tratamiento con prebióticos o placebo. El tratamiento consistió en 3 semanas de suplementación con 15 gd I-PHGG (grupo de fibras) o maltodextrina (grupo placebo). Malestar abdominal, flatulencia, consistencia de las heces, y los movimientos intestinales se evaluaron mediante un cuestionario de registro diario y una entrevista semanal. Cambios en la población de bacterias fecales y los ácidos grasos de cadena corta fueron evaluados por PCR entiempo real y cromatografía de gases, respectivamente. Resultados: Hubo un aumento en la frecuencia de las evacuaciones intestinales por semana y la satisfacción del paciente, tanto en la fibra y el grupo placebo, sin diferencias significativas. El total de Clostridium sp disminuyó significativamente en el grupo de fibras (p = 0,046) y aumentó en el grupo placebo (p = 0,047). No hubo cambios en el perfil fecal de ácidos grasos de cadena corta. Conclusiones: El consumo de I-PHGG ha producido resultados clínicos comparables a placebo en mujeres con estreñimiento, pero ofreció otros efectos protectores sobre la microbiota intestinal al disminuir la cantidad de bacterias patológicas de lo género Clostridium (AU)


Assuntos
Humanos , Feminino , Constipação Intestinal/dietoterapia , Biota , Extratos Vegetais/farmacocinética , Inulina/farmacocinética , Cyamopsis , Clostridium , Ácidos Graxos Voláteis/análise
15.
Nutr. hosp ; 26(6): 1283-1295, nov.-dic. 2011. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-104802

RESUMO

Although diet composition has been implicated as a major factor in the etiology of various gastrointestinal diseases, conclusive evidence remains elusive. This is particularly true in diseases such as necrotizing enterocolitis where breast milk as opposed to commercial formula appears to confer a ‘protective effect’ to the ‘immature gut’. Yet the mechanism by which this occurs continues to remain speculative. In the present study we hypothesize that the basic chemical composition of diet fundamentally selects for specific intestinal microbiota which may help explain disparate disease outcome and therapeutic direction. Complimentary animal and human studies were conducted on young piglets (21 d.)(n = 8)(IACUC protocols 08070 and 08015) and premature infants (adjusted gestational age 34-36 weeks) (n = 11)(IRB Protocol 15895A). In each study, cecal or stool contents from two groups (Breast milk-fed (BF) vs. Formulafed (FF)) were analyzed by gas chromatography/masss pectrometry (GC/MS) and comprehensive metabolic profiles generated and compared. Concurrently, bacterial community structure was assayed and respective representative microbiota of the groups determined by 16SrRNA gene amplicon pyrosequencing. Statistical modeling and analysis was done using SIMCA-P+ and R software. GC/MS metabolomics identified clear differences between BF and FF groups in the intestinal environment of piglets and humans. Sugars, amino-sugars, fatty acids, especially unsaturated fatty acids, and sterols were identified as being among the most important metabolites for distinguishing between BF and FF groups. Joint analysis (AU)


Aunque se ha implicado a la composición de la dieta como un factor principal en la etiología de varias enfermedades gastrointestinales, la evidencia concluyente sigue siendo esquiva. Esto es particularmente cierto en enfermedades como la enterocolitis necrosante en la que la leche materna, en contraposición de las fórmulas comerciales, parece conferir un ‘efecto protector’ para el ‘intestino inmaduro’ o el ecosistema intestinal juvenil del ‘intestino inmaduro’, si bien el mecanismo por el que esto ocurre sigue siendo una especulación. La hipótesis de nuestro estudio es que la composición química básica de la dieta selecciona fundamentalmente microbióticos intestinales específicos que pueden explicar los resultados dispares de la enfermedad y tener implicaciones terapéuticas. Se realizaron estudios adicionales en animales y humanos en lechones (21 d.) (n = 8) (protocolos IACUC08070 y 08015) y lactantes prematuros (edad gestacional ajustada de 34-36 semanas) (n = 11) (Protocolo IRB15895A). En cada estudio, se analizaron los contenidos cecales y fecales de ambos grupos (alimentación materna(AM) y alimentación con fórmula (AF)) mediante cromatografía de gases/espectrometría de masas (CG/EM) y se generaron y compararon perfiles metabólicos completos. De forma concurrente, se probó la estructura de la comunidad bacteriana y se determinaron los representantes (AU)


Assuntos
Humanos , Masculino , Feminino , Recém-Nascido , Doenças do Prematuro/dietoterapia , Biota , Metabolômica/métodos , Intestinos/microbiologia , Leite Humano/microbiologia
16.
Int. microbiol ; 14(3): 155-162, sept. 2011. ilus, tab
Artigo em Inglês | IBECS | ID: ibc-98738

RESUMO

Oenococcus oeni is an alcohol-tolerant, acidophilic lactic acid bacterium that plays an important role in the elaboration of wine. It is often added as a starter culture to carry out malolactic conversion. Given the economic importance of this reaction, the taxonomic structure of this species has been studied in detail. In the present work, phenotypic and molecular approaches were used to identify 121 lactic acid bacteria strains isolated from the wines of three winemaking regions of Portugal. The strains were differentiated at the genomic level by M13-PCR fingerprinting. Twenty-seven genomic clusters represented by two or more isolates and 21 single-member clusters, based on an 85% similarity level, were recognized by hierarchic numerical analysis. M13-PCR fingerprinting patterns revealed a high level of intraspecific genomic diversity in O. oeni. Moreover, this diversity could be partitioned according to the geographical origin of the isolates. Thus, M13-PCR fingerprint analysis may be an appropriate methodology to study the O. oeni ecology of wine during malolactic fermentation as well as to trace new malolactic starter cultures and evaluate their dominance over the native microbiota (AU)


No disponible


Assuntos
Oenococcus/isolamento & purificação , Vinho/microbiologia , Biota , Portugal , Ácido Láctico/análise , Variação Genética , Bacteriófago M13/ultraestrutura
17.
Int. microbiol ; 14(2): 83-93, jun. 2011. ilus
Artigo em Inglês | IBECS | ID: ibc-93476

RESUMO

The bacterial microbiota from the whole gut of soldier and worker castes of the termite Reticulitermes grassei was isolated and studied. In addition, the 16S rDNA bacterial genes from gut DNA were PCR-amplified using Bacteria-selective primers, and the 16S rDNA amplicons subsequently cloned into Escherichia coli. Sequences of the cloned inserts were then used to determine closest relatives by comparison with published sequences and with sequences from our previous work. The clones were found to be affiliated with the phyla Spirochaetes, Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Synergistetes, Verrucomicrobia, and candidate phyla Termite Group 1 (TG1) and Termite Group 2 (TG2). No significant differences were observed with respect to the relative bacterial abundances between soldier and worker phylotypes. The phylotypes obtained in this study were compared with reported sequences from other termites, especially those of phylotypes related to Spirochaetes, Wolbachia (an Alphaproteobacteria), Actinobacteria, and TG1. Many of the clone phylotypes detected in soldiers grouped with those of workers. Moreover, clones CRgS91 (soldiers) and CRgW68 (workers), both affiliated with ‘Endomicrobia’, were the same phylotype. Soldiers and workers also seemed to have similar relative protist abundances. Heterotrophic, poly-β-hydroxyalkanoate-accumulating bacteria were isolated from the gut of soldiers and shown to be affiliated with Actinobacteria and Gammaproteobacteria. We noted that Wolbachia was detected in soldiers but not in workers. Overall, the maintenance by soldiers and workers of comparable axial and radial redox gradients in the gut is consistent with the similarities in the prokaryotes and protists comprising their microbiota (AU)


No disponible


Assuntos
Animais , Gástrula/microbiologia , Biota , Isópteros/patogenicidade , Spirochaetales/isolamento & purificação , Proteobactérias/isolamento & purificação , Bacteroidetes/isolamento & purificação , Actinobacteria/isolamento & purificação
18.
Endocrinol. nutr. (Ed. impr.) ; 57(8): 381-390, oct. 2010.
Artigo em Espanhol | IBECS | ID: ibc-95257

RESUMO

La aplicación reciente de conceptos de la evolución sobre la patología humana está siendo útil para comprender ciertos mecanismos fisiopatológicos de diferentes entidades, que abarcan alteraciones genómicas, de la inmunidad, del funcionalismo respiratorio, hormonal y de los sistemas circulatorio y neuronal. Pero donde ha habido un mayor esfuerzo ha sido en conocer y en explicar las claves de la adaptación que han definido el metabolismo humano y, desde principios de la década de 1960 del siglo anterior, han ido apareciendo distintas teorías. En este artículo se pretende revisar algunas de las hipótesis planteadas durante los últimos años en relación con el potencial beneficio de la resistencia a la insulina y exponer cuál es el conocimiento más reciente. Con los conocimientos actuales queda definitivamente superado el concepto del gen ahorrador. El paradigma actual describe una interacción entre los sistemas metabólico e inmunológico, resultado de una coevolución de los dos sistemas, promovida por las presiones evolutivas desencadenadas por el ayuno, la infección y el tipo de ingesta. Su activación y su regulación de forma integrada e interdependiente definen la resistencia a la insulina como una estrategia de supervivencia en situaciones de ayuno y, especialmente, de infección. Precisamente, su relación con algunos componentes de la dieta y muy especialmente con la flora simbiótica, la microflora intestinal, apunta hacia nuevos paradigmas en la comprensión de la fisiopatología de la obesidad, el síndrome metabólico y la diabetes mellitus tipo 2 (AU)


The recent application of concepts of evolution to human disease is proving useful to understand certain pathophysiological mechanisms of different entities that span genomic alterations of immunity, respiratory and hormone function, and the circulatory and neural systems. However, effort has concentrated on explaining the keys to adaptation that define human metabolism and, since the early 1960s, several theories have been developed. This article reviews some of the hypotheses postulated in recent years on the potential benefit of insulin resistance and discusses the most recent knowledge. The concept of the thrifty gene seems to have been definitively refuted by current knowledge. The current paradigm describes an interaction between the metabolic and the immune systems resulting from their coevolution, promoted by evolutionary pressures triggered by fasting, infection and intake of different foods. The activation and regulation of these ancient mechanisms in integrated and interdependent areas defines insulin resistance as a survival strategy that is critical during fasting and in the fight against infection. The relationship with some components of the diet and, particularly, with the symbiotic intestinal microflora points to new paradigms in understanding the pathophysiology of obesity, metabolic syndrome and type 2 diabetes mellitus (AU)


Assuntos
Humanos , Resistência à Insulina/fisiologia , Diabetes Mellitus/metabolismo , Obesidade/fisiopatologia , Biota , Evolução Biológica , Inflamação/fisiopatologia , Encéfalo/crescimento & desenvolvimento , Desenvolvimento Humano , Jejum/metabolismo
19.
Rev. iberoam. micol ; 26(4): 233-237, dic. 2009. tab
Artigo em Inglês | IBECS | ID: ibc-76136

RESUMO

El trigo (como afrechillo) y el maíz (como grano seco o alimento fermentado) son ingredientes empleados como alimento para el ganado bovino y porcino en la zona sur de la provincia de Buenos Aires (Argentina). Determinar la micobiota y las micotoxinas presentes en estos alimentos es de suma importancia para establecer técnicas de control de los mismos, optimizar la producción animal y minimizar su toxicidad. Por ende, en el sudeste de la provincia de Buenos Aires se llevó a cabo un estudio para identificar la micobiota y las principales micotoxinas presentes en dichos tipos de alimento. Las muestras fueron sembradas para realizar el recuento, el aislamiento y la identificación de los principales géneros de hongos presentes, y analizadas para detectar las micotoxinas de mayor importancia toxicológica: desoxinivalenol (DON), zearalenona (ZEA), toxina T-2 y aflatoxinas (AFLA). Penicillium (74%), Aspergillus (32%) y Scopulariopsis (21%) fueron los géneros más frecuentes en alimentos fermentados. En muestras de maíz, los géneros más relevantes fueron Penicillium (70%), Fusarium (47%) y Aspergillus (34%), mientras que Penicillium (42%), Fusarium (27%) y Alternaria (25%) fueron los más aislados en el caso del afrechillo de trigo. DON fue detectado en el 59% de las muestras de maíz, en el 45% de las muestras de trigo y en el 38% de las muestras de alimento fermentado. ZEA fue detectada en un 36% de las muestras de maíz, en un 49% de las muestras de trigo y en un 16% de las muestras de alimento fermentado. Las toxinas T-2 y aflatoxina B1 fueron detectadas en un 4% de las muestras de maíz. El 18% de las muestras de alimentos fermentados mostraron contaminación con T-2. Las muestras de alimentos fermentados y de trigo fueron negativas para AFLA(AU)


Wheat (as bran) and corn (as dry grain or fermented feed) are main ingredients of feedstuffs used in local cattle and pig farms in the South of the Buenos Aires Province (Argentina). Therefore, determining mycobiota and mycotoxins in wheat and corn is of prime importance for developing feed management techniques to optimise animal production and to minimize toxicity. Then, a mycological survey was carried out in the Southeastern part of the Buenos Aires Province, in order to identify the mycobiota and the main mycotoxins present in fermented feed, wheat grain and corn grain samples. Samples were cultured for fungal quantification, isolation and identification, and analysed for deoxynivalenol (DON), zearalenone (ZEA), T-2 toxin and aflatoxins (AFLA). Penicillium (74%), Aspergillus (32%) and Scopulariopsis (21%) were the prevalent genera in fermented feed. Penicillium (70%), Fusarium (47%) and Aspergillus (34%) were the most frequent fungi isolated from corn. Penicillium (42%), Fusarium (27%) and Alternaria (25%) were the most frequently recovered genera from wheat. DON was detected in 59% of the corn samples, in 45% of the wheat samples and in 38% of the silage samples. ZEA was detected in 36% of the corn samples, in 49% of the wheat samples and in 16% of the silage samples. T-2 toxin and aflatoxin B1 were each detected in 4% of the corn samples. Eighteen percent of the fermented feed samples showed T-2 contamination. Fermented feed and wheat samples were negative for AFLA(AU)


Assuntos
Micotoxinas/isolamento & purificação , Biota/análise , Grão Comestível/microbiologia , Triticum/microbiologia , Zea mays/microbiologia , Produtos Fermentados do Leite/microbiologia
20.
Acta pediatr. esp ; 67(9): 437-442, oct. 2009. tab
Artigo em Espanhol | IBECS | ID: ibc-81303

RESUMO

La obesidad es uno de los principales problemas de salud pública debido al rápido aumento de su prevalencia y a su alta comorbilidad con diversas enfermedades, como el síndrome metabólico, la diabetes y las enfermedades cardiovasculares. Los cambios sociales asociados a una elevada ingesta de alimentos con alta carga energética y una baja actividad física han creado un entorno propenso a la obesidad en todo el mundo. En este contexto, la identificación de nuevos factores implicados en la regulación del balance energético es fundamental a fin de desarrollar estrategias de intervención más eficaces. La microbiota intestinal se considera un nuevo factor implicado en la regulación del peso corporal y las enfermedades asociadas a la obesidad, dada su influencia en las funciones metabólicas e inmunológicas del hospedador. La microbiota intestinal y algunos probióticos también regulan las funciones inmunológicas del individuo, protegiéndolo frente a infecciones y procesos de inflamación crónica. En cambio, los desequilibrios en el ecosistema intestinal (disbiosis) y la endotoxemia pueden ser factores inflamatorios responsables del desarrollo de resistencia a la insulina y del aumento del peso corporal. En función de las relaciones establecidas entre la microbiota intestinal, el metabolismo y la inmunidad, el uso de estrategias dietéticas destinadas a modular la composición de la microbiota, basadas en probióticos y prebióticos, podría contribuir al control de los trastornos metabólicos de forma más eficaz (AU)


Obesity is one of the main public health problems due to its fast prevalence increase and co-morbidities with several diseases, as the metabolic syndrome, diabetes and cardiovascular diseases. Social changes associated to high intake of energy-dense food and low physical activities have created an obesogenic environment worldwide. In this context, the identification of new factors involved in the regulation of the energy balance has mainly the aim of developing more efficient intervention strategies. The intestinal microbiota is considered a new factor involved in the body weight regulation and in diseases associated with obesity through its influence in the metabolic and immunologic functions of the host. The intestinal microbiota and some probiotics also regulate the subject's immunological functions, protecting from infections and chronic inflammation processes. Instead, disorders in the intestinal ecosystem (dysbiosis) and endotoxemia might be inflammatory factors responsible for developing insulin resistance and body weight gain. Based on the relations between the intestinal microbiota, the metabolism and immunity, the use of dietary strategies to modulate the microbiota, based on probiotics and prebiotics, is likely to contribute to the control of the metabolic disorders more efficiently (AU)


Assuntos
Humanos , Doenças Metabólicas/fisiopatologia , Obesidade/fisiopatologia , Biota/análise , Probióticos , Diabetes Mellitus/fisiopatologia , Inflamação/fisiopatologia
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