Development of a multilocus sequence typing method for analysis of Lactobacillus plantarum strains

Lactobacillus plantarum is a species of considerable industrial and medical interest. To date, the lack of reliable molecular methods for definite identification at strain level has hindered studies of the population biology of this organism. Here, a multilocus sequence typing (MLST) system for this organism is described, which exploits the genetic variation present in six housekeeping loci to determine the genetic relationship among isolates. The MLST system was established using 16 L. plantarum strains that were also characterized by ribotyping and restriction fragment length polymorphism (RFLP) analysis of the PCR-amplified 16S–23S rDNA intergenic spacer region (ISR). Ribotyping grouped the strains into four groups; however, RFLP analysis of the ISRs showed no differences in the strains analysed. In contrast, MLST had a good discriminatory ability. The sequence analysis of the six genes showed 14 different allelic combinations, with 12 of them represented by only one strain. By using this MLST approach we were able to confirm the identity of two strains deposited in the Spanish Type Culture Collection as different strains. Phylogenetic analysis indicated a panmictic population structure of L. plantarum and split decomposition analysis indicated that recombination plays a role in creating genetic heterogeneity in L. plantarum. As MLST allows precise identification, and easy comparison and exchange of results obtained in different laboratories, the future application of this new molecular method could be useful for the identification of valuable L. plantarum strainsThis work has been supported by grants AGL2005-00470 and RM03- 002. We thank R. Gonza´lez and E. Garcı´a for their critical reading of the manuscript. The technical assistance of M. V. Santamarı´a is greatly appreciated. We also thank A. Hexter for correcting the English version. B. de las Rivas is a recipient of a postdoctoral fellowship and A. Marcobal of a predoctoral fellowship both from the Comunidad de Madrid.Peer reviewe

Development of new laboratory equipment for measuring the accelerated polishing of asphalt mixes

The skid resistance of pavements tends to decrease over time, resulting in greater risks for drivers. Currently, skid resistance and macrotexture values can only be determined for existing pavements. It would be of interest to be able to predict the evolution of the skid resistance of an asphalt mixture before its installation as a highway wearing course. This paper summarizes the experience gained and the results obtained during the development of a test procedure which has been applied in the laboratory to measure the evolution of the skid resistance of hot mix asphalts through a modified version of an accelerated polishing machine which is normally used to determine the polished stone value of aggregates

Factors affecting the production of putrescine from agmatine by Lactobacillus hilgardii X1B isolated from wine

Aims: To elucidate and characterize the metabolic putrescine synthesis pathway from agmatine by Lactobacillus hilgardii X1B. Methods and Results: The putrescine formation from agmatine by resting cells (the normal physiological state in wine) of lactic acid bacteria isolated from wine has been determined for the first time. Agmatine deiminase and N-carbamoylputrescine hydrolase enzymes, determined by HPLC and LC-Ion Trap Mass Spectrometry, carried out the putrescine synthesis from agmatine. The influence of pH, temperature, organic acids, amino acids, sugars and ethanol on the putrescine formation in wine was determined. Conclusions: Resting cells of Lact. hilgardii X 1B produce putrescine in wine. The putrescine production was carried out from agmatine through the agmatine deiminase system. Significance and Impact of the Study: These results have significance from two points of view, wine quality and toxicological and microbiological aspects, taking account that putrescine, which origin is still controversial, is quantitatively the main biogenic amine found in wine. © 2008 The Authors.Fil: Arena, Mario Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto de Química del Noroeste. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia. Instituto de Química del Noroeste; ArgentinaFil: Landete, J. M.. Universidad de Valencia; EspañaFil: Manca, Maria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Pardo, I.. Universidad de Valencia; EspañaFil: Ferrer, S.. Universidad de Valencia; Españ

Establishing What Constitutes a Healthy Human Gut Microbiome: State of the Science, Regulatory Considerations, and Future Directions.

On December 17, 2018, the North American branch of the International Life Sciences Institute (ILSI North America) convened a workshop "Can We Begin to Define a Healthy Gut Microbiome Through Quantifiable Characteristics?" with >40 invited academic, government, and industry experts in Washington, DC. The workshop objectives were to 1) develop a collective expert assessment of the state of the evidence on the human gut microbiome and associated human health benefits, 2) see if there was sufficient evidence to establish measurable gut microbiome characteristics that could serve as indicators of "health," 3) identify short- and long-term research needs to fully characterize healthy gut microbiome-host relationships, and 4) publish the findings. Conclusions were as follows: 1) mechanistic links of specific changes in gut microbiome structure with function or markers of human health are not yet established; 2) it is not established if dysbiosis is a cause, consequence, or both of changes in human gut epithelial function and disease; 3) microbiome communities are highly individualized, show a high degree of interindividual variation to perturbation, and tend to be stable over years; 4) the complexity of microbiome-host interactions requires a comprehensive, multidisciplinary research agenda to elucidate relationships between gut microbiome and host health; 5) biomarkers and/or surrogate indicators of host function and pathogenic processes based on the microbiome need to be determined and validated, along with normal ranges, using approaches similar to those used to establish biomarkers and/or surrogate indicators based on host metabolic phenotypes; 6) future studies measuring responses to an exposure or intervention need to combine validated microbiome-related biomarkers and/or surrogate indicators with multiomics characterization of the microbiome; and 7) because static genetic sampling misses important short- and long-term microbiome-related dynamic changes to host health, future studies must be powered to account for inter- and intraindividual variation and should use repeated measures within individuals

Bacteroides thetaiotaomicron generates diverse α-mannosidase activities through subtle evolution of a distal substrate-binding motif

A dominant human gut microbe, the well studied symbiont Bacteroides thetaiotaomicron (Bt), is a glyco-specialist that harbors a large repertoire of genes devoted to carbohydrate processing. Despite strong similarities among them, many of the encoded enzymes have evolved distinct substrate specificities, and through the clustering of cognate genes within operons termed polysaccharide-utilization loci (PULs) enable the fulfilment of complex biological roles. Structural analyses of two glycoside hydrolase family 92 α-mannosidases, BT3130 and BT3965, together with mechanistically relevant complexes at 1.8–2.5 Å resolution reveal conservation of the global enzyme fold and core catalytic apparatus despite different linkage specificities. Structure comparison shows that Bt differentiates the activity of these enzymes through evolution of a highly variable substrate-binding region immediately adjacent to the active site. These observations unveil a genetic/biochemical mechanism through which polysaccharide-processing bacteria can evolve new and specific biochemical activities from otherwise highly similar gene products

Metabolic phenotyping for understanding the gut microbiome and host metabolic interplay

There is growing interest in the role of the gut microbiome in human health and disease. This unique complex ecosystem has been implicated in a number of health conditions including intestinal disorders, inflammatory skin diseases and metabolic syndrome. However, there is still much to learn regarding its capacity to affect host health. Many gut microbiome research studies focus on compositional analysis to better understand the causal relationships between microbial communities and disease phenotypes. Yet microbial diversity and complexity is such, that community structure alone does not provide full understanding of microbial function. Metabolic phenotyping is an exciting field in systems biology that provides information on metabolic outputs taking place in the system at a given moment in time. These readouts provide information relating to by-products of endogenous metabolic pathways, exogenous signals arising from diet, drugs and other lifestyle and environmental stimuli, as well as products of microbe-host co-metabolism. Thus, better understanding of the gut microbiome and host metabolic interplay can be gleaned by using such analytical approaches. In this Review, we describe research findings focussed on gut microbiota-host interactions, for functional insight into the impact of microbiome composition on host health. We evaluate different analytical approaches for capturing metabolic activity, and discuss analytical methodological advancements that have made a contribution to the field. This information will aid in developing novel approaches to improve host health in the future, and therapeutic modulation of the microbiome may soon augment conventional clinical strategies

Community Mannagement i gestió dels social media a les galeries d'art

Màster Oficial en Estudis Avançats en Història de l'Art. Facultat de Geografia i Història de la UB. Curs: 2015-2016, Tutor: Joan Ramon Triadó TurL’ús generalitzat dels mitjans socials (social media) actualment és indiscutible, tant en l’àmbit personal com en el professional. Són moltes les persones que tenen almenys un perfil en una d’aquestes plataformes de les tantes que existeixen, i com elles, també s’han sumat a la tendència les organitzacions en un pla més general. Per tant, en aquest apartat es farà una primera aproximació al panorama general en l’ús de les principals eines, amb l’objectiu d’identificar aquelles que compten amb un major nombre d’usuaris, però també per evidenciar la necessitat, per part de les organitzacions, d’adaptar-se al món digital a fi de trobar-hi els seus seguidors. A dia d’avui, dels més de set mil milions d’habitants a la Terra, 3.419 milions són usuaris d’internet, el que significa una penetració del 46% del total. De tota aquesta massa internauta, 2.307 milions són usuaris actius d’almenys una xarxa social o plataforma de compartició de contingut, el que significa que el 31% de la població mundial forma part d’alguna de les múltiples xarxes online existents1. Aquestes dades evidencien el gran desplegament a nivell mundial i consoliden la xarxa com una nova eina de comunicació entre les persones en un món globalitzat. Aquestes dades corresponen a gener de 2016; respecte al gener de 2015, els índexs han anat en augment: enguany hi ha un 10% més de població amb accés a internet i un 10% més d’usuaris actius a les xarxes socials2. El creixement dóna compte que la tendència cada cop se situa a l’alça, sense haver arribat encara al punt culminant en l’ús d’internet i dels mitjans socials

Elaboración de un indicador para la evaluación funcional de pavimentos en terminales portuarias de contenedores

Este trabajo ha tenido como objetivo fundamental definir un indicador para la evaluación funcional de pavimentos de hormigón en terminales portuarias de contenedores. El indicador propuesto se calcula mediante una expresión matemática y permite clasificar los pavimentos de las diferentes zonas de las terminales basándose en dos aspectos: valoración del deterioro y priorización de las zonas. La valoración del deterioro cuantifica su densidad en los pavimentos inspeccionados mientras que la priorización clasifica los pavimentos en función de la importancia de la terminal y del uso de la zona en la que se ubiquen. La primera parte del trabajo ha consistido en definir el modo en que se va realizar la valoración del deterioro del pavimento. Para ello, se ha seleccionado un parámetro de cuantificación de deterioro basándose en el estudio de los deterioros más representativos y en su con-elación con el tráfico y la edad de los pavimentos estudiados. Este parámetro seleccionado es el utilizado para la valoración del deterioro. La segunda parte del trabajo ha consistido en desarrollar la parte del indicador que realiza la priorización de las muestras en función de la importancia de la terminal y del uso de la zona. Se ha valorado la importancia de la terminal mediante el parámetro "Índice de intensidad de uso" tal y como está definido en la ROM 4.1-94. Por otro lado, se ha definido un procedimiento para valorar la importancia de la zona de la terminal teniendo en cuenta su uso principal. Para ello, se ha realizado un estudio Delphi con un panel de expertos constituido por técnicos portuarios. Como resultado de este panel se han obtenido un procedimiento basado en tablas que permiten obtener una valoración de la importancia de cada zona. El método Delphi también ha permitido obtener el valor relativo que los técnicos portuarios otorgan a la importancia de la terminal y de la zona donde se ubican las muestras. Una vez definido el indicador, se ha propuesto una metodología completa para la aplicación del indicador funcional propuesto. Para ello ha sido necesario establecer dos valores umbrales del parámetro de cuantificación de deterioro: de alerta y de actuación. Cuando el indicador alcance estos valores, la actuación sobre el pavimento será recomendable u obligatoria respectivamente. Estos umbrales se han definido mediante un panel de expertos. The principal aim of this thesis is to define an index for concrete pavement functional condition evaluation in port container terminals. The proposed index, calculated through a mathematical equation, enables the classification of different terminal areas based on two factors; distress evaluation and area prioritization. Distress evaluation quantifies its density on surveyed pavements, while area prioritization classifies pavements on the basis of terminal importance and area specific use. Firstly, a method for pavement distress evaluation has been defined. A distress quantification parameter was developed based on analysis of the most representative distresses and their correlation with traffic and age of surveyed pavements. The selected parameter is used for distress evaluation. Subsequently an index factor was developed to prioritize pavement sections taking into consideration terminal importance and area specific use. Terminal importance was evaluated by means of "Port operation index" as defined in ROM 4.1-94. A procedure was also established in order to evaluate terminal area importance taking into consideration its specific use. This procedure was carried out using a Delphi expert opinion panel using port technicians. This study has lead to a table-based assessment procedure for the evaluation of each area of importance. The Delphi method study has also provided the relative value that port technicians attribute to terminal importance and area specific use. Finally, a full methodology is proposed for the application of the new defined index. This has required the establishment of two threshold factors for the distress quantification parameter: warning and action. When the index exceeds these values, maintenance works will be preventive or required respectively. These thresholds were defined also by means of an expert panel

Replicating phages in the epidermal mucosa of the eel (anguilla anguilla)

n this work, we used the eel (Anguilla anguilla) as an animal model to test the hypothesis of Barr et al. (2013a,b) about the putative role of the epidermal mucosa as a phage enrichment layer. To this end, we analyzed the microbial content of the skin mucus of wild and farmed eels by using a metagenomic approach. We found a great abundance of replicating phage genomes (concatemers) in all the samples. They were assembled in four complete genomes of three Myovirus and one Podovirus. We also found evidences that ΦKZ and Podovirus phages could be part of the resident microbiota associated to the eel mucosal surface and persist on them over the time. Moreover, the viral abundance estimated by epiflorescent counts and by metagenomic recruitment from eel mucosa was higher than that of the surrounding water. Taken together, our results support the hypothesis that claims a possible role of phages in the animal mucus as agents controlling bacterial populations, including pathogenic species, providing a kind of innate immunity