Aplicación de un sistema de información geográfica para visualizar vías pecuarias y obtener información sobre las mismas a partir de imágenes de satélite SPOT

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Identification and modeling of a novel chloramphenicol resistance protein detected by functional metagenomics in a wetland of Lerma, Mexico

The exploration of novel antibiotic resistance determinants in a particular environment may be limited because of the presence of uncultured microorganisms. In this work, a culture independent approach based on functional metagenomics was applied to search for chloramphenicol resistance genes in agro-industrial wastewater in Lerma de Villada, Mexico. To this end, a metagenomic library was generated in Escherichia coli DH10B containing DNA isolated from environmental samples of the residual arsenic-enriched (10 mg/ml) effl uent. One resistant clone was detected in this library and further analyzed. An open reading frame similar to a multidrug resistance protein from Aeromonas salmonicida and responsible for chloramphenicol resistance was identifi ed, sequenced, and found to encode a member of the major facilitator superfamily (MFS). Our results also showed that the expression of this gene restored streptomycin sensitivity in E. coli DH10B cells. To gain further insight into the phenotype of this MFS family member, we developed a model of the membrane protein multiporter that, in addition, may serve as a template for developing new antibiotics. [Int Microbiol 2013; 16(2):103-111]Keywords: Escherichia coli; chloramphenicol; functional metagenomics; major facilitator superfamily; homology models; membrane proteins; arseni

Growth at moulth, intermoult period and moulting seasonality of the spider crab "Maja brachydactyla" : combining information from mark-recapture and experimental studies

[Abstract] An analysis of growth at moult (for both the prepubertal and terminal moults), moulting seasonality and the intermoult period in the spider crab Maja squinado in the Ría de A Coruña (NW Spain) was carried out based on a mark-recapture experiment. Crabs between 70 and 130 mm carapace length (CL) undergo a mean increase at moult of 32.4% from their pre-moult size. Generalised Linear Models (GLMs) were used to construct growth models, employing a combination of information from the mark-recapture study and other previous studies performed in both laboratory and extensive culture, to estimate the effects of the biological variables and the study method. No differences were found in the growth rate between males and females. However, the effects of the study method, the premoult CL and the interaction between them were significant. The smallest-sized crabs undergo a greater increase in size in the laboratory and culture studies, while the largest individuals undergo greater growth in the field. The mean intermoult period estimated for prepubertal moults in the field ranged from 50 to 86 days, which Corgos et al., GROWTH AT MOULT OF MAJA BRACHYDACTYLA is similar to the 84.7 days observed in the laboratory study. The prepubertal moults occurred primarily in spring and autumn in the field, while under culture conditions, the crabs moulted mainly in the spring. The intermoult period for terminal moults was estimated to be around 90 days, slightly lower than the value of 104 days obtained in the laboratory. The terminal moult took place generally in summer (June-September) both at sea as well as in culture experiments. The intermoult period of juveniles at sea was highly variable, and some of the specimens did not moult for more than 5 months.Ministerio de Ciencia y Tecnología; REN2000-0446MARXunta de Galicia; XUGA10301B9

Salt resistance genes revealed by functional metagenomics from brines and moderate-salinity rhizosphere within a hypersaline environment

Hypersaline environments are considered one of the most extreme habitats on earth and microorganisms have developed diverse molecular mechanisms of adaptation to withstand these conditions. The present study was aimed at identifying novel genes from the microbial communities of a moderate-salinity rhizosphere and brine from the Es Trenc saltern (Mallorca, Spain), which could confer increased salt resistance to Escherichia coli. The microbial diversity assessed by pyrosequencing of 16S rRNA gene libraries revealed the presence of communities that are typical in such environments and the remarkable presence of three bacterial groups never revealed as major components of salt brines. Metagenomic libraries from brine and rhizosphere samples, were transferred to the osmosensitive strain E. coli MKH13, and screened for salt resistance. Eleven genes that conferred salt resistance were identified, some encoding for well-known proteins previously related to osmoadaptation such as a glycerol transporter and a proton pump, whereas others encoded proteins not previously related to this function in microorganisms such as DNA/RNA helicases, an endonuclease III (Nth) and hypothetical proteins of unknown function. Furthermore, four of the retrieved genes were cloned and expressed in Bacillus subtilis and they also conferred salt resistance to this bacterium, broadening the spectrum of bacterial species in which these genes can function. This is the first report of salt resistance genes recovered from metagenomes of a hypersaline environment. © 2015 Mirete, Mora-Ruiz, Lamprecht-Grandío, de Figueras, Rosselló-Móra and González-Pastor.This work was funded by the Spanish Ministry of Science and Innovation (CGL2012-39627-C03/02 and 03); the latter also supported with European Regional Development Fund (FEDER). MM-R Ph.D. is supported by fellowship CVU 265934 of the National Council of Science and Technology (CONACyT), MexicoPeer Reviewe

The role of nitric-oxide-synthase-derived nitric oxide in multicellular traits of Bacillus subtilis 3610: biofilm formation, swarming, and dispersal

<p>Abstract</p> <p>Background</p> <p><it>Bacillus subtilis </it>3610 displays multicellular traits as it forms structurally complex biofilms and swarms on solid surfaces. In addition, <it>B. subtilis </it>encodes and expresses nitric oxide synthase (NOS), an enzyme that is known to enable NO-mediated intercellular signalling in multicellular eukaryotes. In this study, we tested the hypothesis that NOS-derived NO is involved in the coordination of multicellularity in <it>B. subtilis </it>3610.</p> <p>Results</p> <p>We show that <it>B. subtilis </it>3610 produces intracellular NO <it>via </it>NOS activity by combining Confocal Laser Scanning Microscopy with the NO sensitive dye copper fluorescein (CuFL). We further investigated the influence of NOS-derived NO and exogenously supplied NO on the formation of biofilms, swarming motility and biofilm dispersal. These experiments showed that neither the suppression of NO formation with specific NOS inhibitors, NO scavengers or deletion of the <it>nos </it>gene, nor the exogenous addition of NO with NO donors affected (i) biofilm development, (ii) mature biofilm structure, and (iii) swarming motility in a qualitative and quantitative manner. In contrast, the <it>nos </it>knock-out and wild-type cells with inhibited NOS displayed strongly enhanced biofilm dispersal.</p> <p>Conclusion</p> <p>The results suggest that biofilm formation and swarming motility in <it>B. subtilis </it>represent complex multicellular processes that do not employ NO signalling and are remarkably robust against interference of NO. Rather, the function of NOS-derived NO in <it>B. subtilis </it>might be specific for cytoprotection against oxidative stress as has been proposed earlier. The influence of NOS-derived NO on dispersal of <it>B. subtilis </it>from biofilms might be associated to its well-known function in coordinating the transition from oxic to anoxic conditions. Here, NOS-derived NO might be involved in fine-tuning the cellular decision-making between adaptation of the metabolism to (anoxic) conditions in the biofilm or dispersal from the biofilm.</p

A Multi-Site NFV Testbed for Experimentation With SUAV-Based 5G Vertical Services

[EN] With the advent of 5G technologies, vertical markets have been placed at the forefront, as fundamental drivers and adopters of technical developments and new business models. Small Unmanned Aerial Vehicles (SUAVs) are gaining traction in multiple vertical sectors, as key assets to generate, process, and distribute relevant information for the provision of value-added services. However, the enormous potential of SUAVs to support a exible, rapid, and cost-effective deployment of vertical applications is still to be exploited. In this paper, we leverage our prior work on Network Functions Virtualization (NFV) and SUAVs to design and build a multi-site experimentation testbed based on open-source technologies. The goal of this testbed is to explore synergies among NFV, SUAVs, and vertical services, following a practical approach primarily governed by experimentation. To verify our testbed design, we realized a reference use case where a number of SUAVs, cloud infrastructures, and communication protocols are used to provide a multi-site vertical service. Our experimentation results suggest the potential of NFV and SUAVs to exibly support vertical services. The lessons learned have served to identify missing elements in our NFV platform, as well as challenging aspects for potential improvement. These include the development of speci c mechanisms to limit processing load and delays of service deployment operations.This work was supported in part by the European Commission under the European Union's Horizon 2020 program (5GRANGE Project, grant agreement number 777137), and in part by the 5GCity Project funded by the Spanish Ministry of Economy and Competitiveness under Grant TEC2016-76795-C6-1R, Grant TEC2016-76795-C6-3R, and Grant TEC2016-76795-C6-5R

Management strategies for sustainable invertebrate fisheries in coastal ecosystems of Galicia (NW Spain)

The original publication in avaliable at www. springerlink.comArtisanal coastal invertebrate fisheries in Galicia are socio-economically important and ecologically relevant. Their management, however, has been based on models of fish population dynamics appropriate for highly mobile demersal or pelagic resources and for industrial fisheries. These management systems focus on regulating fishing effort, but in coastal ecosystems activities that change or destruct key habitats may have a greater effect on population abundance than does fishing mortality. The Golfo Artabro was analysed as a representative example of a coastal ecosystem in Galicia, and the spider crab "Maja squinado" used as a model of an exploited coastal invertebrate, for which shallow coastal areas are key habitats for juvenile stages. The commercial legal gillnet fishery for the spider crab harvests adults during their reproductive migrations to deep waters and in their wintering habitats. Illegal fisheries operate in shallow waters. The annual rate of exploitation is higher to 90%, and lower to 10% of the primiparous females reproduce effectively at least once. A simple spatially-explicit cohort model was constructed to simulate the population dynamics of spider crab females. Yield- and egg-per-recruit analyses corresponding to different exploitation regimes were performed to compare management policies directed to control the fishing effort or to protect key habitats. It was found that the protection of juvenile habitats could allow increases in yield and reproductive effort higher than in the present system, with such protection based in the control of the fishing effort of the legal fishery. Additionally, there is an urgent need for alternative research and management strategies in artisanal coastal fisheries based on the implementation of a system of territorial use rights for fishers, the integration of the fishers into assessment and management processes, and the protection of key habitats (marine reserves) as a basic tool for the regulation of the fisheries.Xunta de Galicia; XUGA10301B9

Temperature increase prevails over acidification in gene expression modulation of amastigote differentiation in Leishmania infantum

<p>Abstract</p> <p>Background</p> <p>The extracellular promastigote and the intracellular amastigote stages alternate in the digenetic life cycle of the trypanosomatid parasite <it>Leishmania</it>. Amastigotes develop inside parasitophorous vacuoles of mammalian phagocytes, where they tolerate extreme environmental conditions. Temperature increase and pH decrease are crucial factors in the multifactorial differentiation process of promastigotes to amastigotes. Although expression profiling approaches for axenic, cell culture- and lesion-derived amastigotes have already been reported, the specific influence of temperature increase and acidification of the environment on developmental regulation of genes has not been previously studied. For the first time, we have used custom <it>L. infantum </it>genomic DNA microarrays to compare the isolated and the combined effects of both factors on the transcriptome.</p> <p>Results</p> <p>Immunofluorescence analysis of promastigote-specific glycoprotein gp46 and expression modulation analysis of the amastigote-specific A2 gene have revealed that concomitant exposure to temperature increase and acidification leads to amastigote-like forms. The temperature-induced gene expression profile in the absence of pH variation resembles the profile obtained under combined exposure to both factors unlike that obtained for exposure to acidification alone. In fact, the subsequent fold change-based global iterative hierarchical clustering analysis supports these findings.</p> <p>Conclusions</p> <p>The specific influence of temperature and pH on the differential regulation of genes described in this study and the evidence provided by clustering analysis is consistent with the predominant role of temperature increase over extracellular pH decrease in the amastigote differentiation process, which provides new insights into <it>Leishmania </it>physiology.</p

Long-term mortality and trajectory of potassium easurements following an episode of acute severe hyperkalemia

Background: Hyperkalaemia is a common condition in patients with comorbidities such as chronic kidney disease (CKD) or congestive heart failure (HF). Moreover, severe hyperkalaemia is a potentially life-threatening condition that is associated with a higher risk of adverse clinical events such as ventricular arrhythmias and sudden cardiac death. Currently, data regarding the prognostic implications of chronic hyperkalaemia are available; however, information about the long-term clinical consequences after an episode of severe hyperkalaemia remains scarce. The objective of this study was to evaluate the association between the trajectory of potassium measurements in patients with acute hyperkalaemia and long-term all-cause mortality. Methods: This is a retrospective observational study that included patients with acute severe hyperkalaemia [potassium (K) >6 mEq/L] without haemolysis in the emergency room of Dr Peset University Hospital in Valencia, Spain searching the lab database from January 2016 to March 2017. The multivariable-adjusted association of serum potassium with mortality was assessed by using comprehensive state-of-the-art regression methods that can accommodate time-dependent exposure modelling. Results: We found 172 episodes of acute hyperkalaemia in 160 patients in the emergency room. The mean ± standard deviation age of the sample was 77 ± 12 years and 60.5% were males. The most frequent comorbidities were CKD (71.2%), HF (35%) and diabetes mellitus (56.9%). Only 11.9% of the patients were on chronic dialysis. A quarter of the patients did not have previous CKD, making hyperkalaemia an unpredictable life-threatening complication. During the acute episode, mean potassium and estimated glomerular filtration rate (eGFR) were 6.6 ± 0.6 (range 6.1-9.2) mEq/L and 23 ± 16 (range 2-84) mL/min/1.73 m2, respectively. After a median (interquartile range) follow-up of 17.3 (2.2-23.7) months, 68 patients died (42.5%). Recurrences of hyperkalaemia (K >5.5 mEq/L) were detected in 39.5% of the patients who were monitored during follow-up. We found that previous potassium levels during an acute severe hyperkalaemia episode were not predictors of mortality. Conversely, the post-discharge longitudinal trajectories of potassium were able to predict all-cause mortality (overall P = 0.0015). The effect of transitioning from hyperkalaemia to normokalaemia (K >5.5 mEq/L to K ≤5.5 mEq/L) after the acute episode was significant, and inversely associated with the risk of mortality. Conclusions: Potassium levels prior to a severe hyperkalaemic event do not predict mortality. Conversely, following an episode of acute severe hyperkalaemia, serial kinetics of potassium trajectories predict the risk of death. Further evidence is needed to confirm these findings and clarify the optimal long-term management of these patients

Novel Genes Involved in Resistance to Both Ultraviolet Radiation and Perchlorate From the Metagenomes of Hypersaline Environments

Microorganisms that thrive in hypersaline environments on the surface of our planet are exposed to the harmful effects of ultraviolet radiation. Therefore, for their protection, they have sunscreen pigments and highly efficient DNA repair and protection systems. The present study aimed to identify new genes involved in UV radiation resistance from these microorganisms, many of which cannot be cultured in the laboratory. Thus, a functional metagenomic approach was used and for this, small-insert libraries were constructed with DNA isolated from microorganisms of high-altitude Andean hypersaline lakes in Argentina (Diamante and Ojo Seco lakes, 4,589 and 3,200 m, respectively) and from the Es Trenc solar saltern in Spain. The libraries were hosted in a UV radiation-sensitive strain of Escherichia coli (recA mutant) and they were exposed to UVB. The resistant colonies were analyzed and as a result, four clones were identified with environmental DNA fragments containing five genes that conferred resistance to UV radiation in E. coli. One gene encoded a RecA-like protein, complementing the mutation in recA that makes the E. coli host strain more sensitive to UV radiation. Two other genes from the same DNA fragment encoded a TATA-box binding protein and an unknown protein, both responsible for UV resistance. Interestingly, two other genes from different and remote environments, the Ojo Seco Andean lake and the Es Trenc saltern, encoded two hypothetical proteins that can be considered homologous based on their significant amino acid similarity (49%). All of these genes also conferred resistance to 4-nitroquinoline 1-oxide (4-NQO), a compound that mimics the effect of UV radiation on DNA, and also to perchlorate, a powerful oxidant that can induce DNA damage. Furthermore, the hypothetical protein from the Es Trenc salterns was localized as discrete foci possibly associated with damaged sites in the DNA in cells treated with 4-NQO, so it could be involved in the repair of damaged DNA. In summary, novel genes involved in resistance to UV radiation, 4-NQO and perchlorate have been identified in this work and two of them encoding hypothetical proteins that could be involved in DNA damage repair activities not previously described.Fil: Lamprecht Grandío, María. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Cortesão, Marta. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Mirete, Salvador. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Benguigui de la Cámara, Macarena. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: de Figueras, Carolina G.. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Pérez Pantoja, Danilo. Universidad Tecnológica Metropolitana; EspañaFil: White, Joseph John. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; EspañaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Rosselló Móra, Ramon. Instituto Mediterráneo Estudios Avanzados; EspañaFil: González Pastor, José Eduardo. Consejo Superior de Investigaciones Cientificas. Centro de Astrobiologia.; Españ