Microorganisms tend to accumulate on surfaces, forming aggregates such as biofilms, which grant them resistance to various environmental stressors and antimicrobial agents. This ability has hindered the effective treatment of diseases caused by pathogenic microorganisms, including Salmonella, which is responsible for a significant number of deaths worldwide. This study aimed to compare the metabolic profiles of planktonic and sessile cells of Salmonella Enteritidis using a metabolomics approach. The metabolites extracted from the bacterial cells were analyzed by LC/MS approach. Raw data were analyzed using Thermo Xcalibur v 3.1 software. For data processing, XCMS was used for feature detection, retention time, correction and alignment. The data matrix was analyzed by uni- and multivariate statistical methods (PCA, PLS-DA, Heatmap) in MetaboAnalyst software v 6.0. A total of 121 metabolites were presumptively identified as differential metabolic characteristics between the two bacterial states, and they were associated with their corresponding metabolic pathways. Among the metabolites that exhibited positive modulation in planktonic cells were proline, phenylalanine, which act as precursors of essential metabolites and part of the stress adaptation mechanisms. In addition, putrescine and cadaverine, play crucial roles in growth, stress response, and cell stability In contrast, the most representative metabolites in sessile cells included lysine, adenosine, purines, pyrimidines, and citrate, mainly associated with maintaining cellular homeostasis, stress response and metabolic regulation. Finally, pathway enrichment analysis identified metabolic changes in 11 pathways, predominantly involving purine and pyrimidine metabolism, arginine and proline metabolism, and vitamin B6 metabolism. These findings facilitated the identification of potential metabolic pathways associated with biofilm formation in the sessile cells of Salmonella Enteritidis.

A mesoporous material was synthesized using silica extracts from fly ash and its properties were studied. Subsequently, it was functionalized with carbamoylmethylphosphine oxide (CMPO) to capture La 3+ and Ce 3+ . The developed mesoporous material was obtained by the sol-gel method and was called Si-MMS (siliceous mesoporous materials), subsequently functionalized with APTMS (1-(2-aminoethyl)-3-aminopropyl trimethoxysilane) in a reflux system, which led to the synthesis of Si-MMS-APTMS. This derivative was modified with carbonyldiimidazole (CDI) and diethylphosphonoacetic acid, which finally resulted in the synthesis of Si-MMS-CMPO as the final product. The materials were characterized by DRIFT, XRD, SEM-EDS, TEM, XPS, elemental analysis and nitrogen isotherms at -196 degrees C, confirming that the synthesis and subsequent modification of the mesoporous structure was successful. Adsorption studies in batch systems indicated that the optimal pH for La 3+ was 6, the Langmuir isotherm model and the non-linear Sips models were perfectly fitted and the best fitting kinetics is the Elovich model. For Ce 3+ the optimal pH was 7.5, the non-linear Sips isotherm fit the best and the non-linear Pseudo -second order kinetics was the mechanism that best represents the adsorption. The maximum experimental adsorption capacity q e of La 3+ was 17.00 mg g -1 and for Ce 3+ was 30.09 mg g -1 . In both cases, the rapid adsorption suggests an open porous matrix that facilitates the formation of chelates between the adsorbates and the phosphoryl group -PO 3 2- .

The high concentration of pig farms in NE Spain makes pig slurries an attractive fertilizer to reduce costs of agricultural production. However, inadequate management of fertilization with pig slurry can cause negative environmental consequences. In this context, a 4 year field trial was carried out to evaluate several fertilization strategies, using pig slurry, for a double-annual forage cropping rotation with barley (Hordeum vulgare L.) and sorghum (Sorghum bicolor L.) under sub-humid Mediterranean conditions. Four nitrogen (N) fertilization treatments applied as pig slurry (0, 170, 250 and 330 kg N ha−1 year−1) were applied and their effects on yield, N uptake, unrecovered N, and residual NO3-N in soil were evaluated for each crop and each rotation. The 4 year average dry matter (DM) forage yield of sorghum was 9.3 Mg ha−1 in all N fertilization treatments, except for the control (0 kg N ha−1) which was 6 Mg ha−1. However, barley DM yields varied among N treatments. The highest barley yield (8.7 Mg DM ha−1) was achieved with the application of 330 kg N ha−1 year−1. The barley yields were reduced by a 26

Nontyphoidal Salmonella species are one of the main bacterial causes of foodborne diseases, causing a public health problem. In addition, the ability to form biofilms, multiresistance to traditional drugs, and the absence of effective therapies against these microorganisms are some of the principal reasons for the increase in bacterial diseases. In this study, the anti-biofilm activity of twenty essential oils (EOs) on Salmonella enterica serovar Enteritidis ATCC 13076 was evaluated, as well as the metabolic changes caused by Lippia origanoides thymol chemotype EO (LOT-II) on planktonic and sessile cells. The anti-biofilm effect was evaluated by the crystal violet staining method, and cell viability was evaluated through the XTT method. The effect of EOs was observed by scanning electron microscopy (SEM) analysis. Untargeted metabolomics analyses were conducted to determine the effect of LOT-II EO on the cellular metabolome. LOT-II EO inhibited S. Enteritidis biofilm formation by more than 60%, without decreasing metabolic activity. Metabolic profile analysis identified changes in the modulation of metabolites in planktonic and sessile cells after LOT-II EO treatment. These changes showed alterations in different metabolic pathways, mainly in central carbon metabolism and nucleotide and amino acid metabolism. Finally, the possible mechanism of action of L. origanoides EO is proposed based on a metabolomics approach. Further studies are required to advance at the molecular level on the cellular targets affected by EOs, which are promising natural products for developing new therapeutic agents against Salmonella sp. strains.

Microbial infections resistant to conventional antibiotics constitute one of the most important causes of mortality in the world. In some bacterial species, such as Escherichia coli and Staphylococcus aureus pathogens, biofilm formation can favor their antimicrobial resistance. These biofilm-forming bacteria produce a compact and protective matrix, allowing their adherence and colonization to different surfaces, and contributing to resistance, recurrence, and chronicity of the infections. Therefore, different therapeutic alternatives have been investigated to interrupt both cellular communication routes and biofilm formation. Among these, essential oils (EO) from Lippia origanoides thymol-carvacrol II chemotype (LOTC II) plants have demonstrated biological activity against different biofilm-forming pathogenic bacteria. In this work, we determined the effect of LOTC II EO on the expression of genes associated with quorum sensing (QS) communication, biofilm formation, and virulence of E. coli ATCC 25922 and S. aureus ATCC 29213. This EO was found to have high efficacy against biofilm formation, decreasing-by negative regulation-the expression of genes involved in motility (fimH), adherence and cellular aggregation (csgD), and exopolysaccharide production (pgaC) in E. coli. In addition, this effect was also determined in S. aureus where the L. origanoides EO diminished the expression of genes involved in QS communication (agrA), production of exopolysaccharides by PIA/PNG (icaA), synthesis of alpha hemolysin (hla), transcriptional regulators of the production of extracellular toxins (RNA III), QS and biofilm formation transcriptional regulators (sarA) and global regulators of biofilm formation (rbf and aur). Positive regulation was observed on the expression of genes encoding inhibitors of biofilm formation (e.g., sdiA and ariR). These findings suggest that LOTCII EO can affect biological pathways associated with QS communication, biofilm formation, and virulence of E. coli and S. aureus at subinhibitory concentrations and could be a promising candidate as a natural antibacterial alternative to conventional antibiotics.

The potential of some soil cyanobacteria to influence plant development through the release of biologically active substances has been extensively characterized. The use of cyanobacterial culture supernatants is among the strategies for this purpose, as they contain compounds that can influence plant development. However, there is little information on how the remaining nutrients from the culture medium used, could contribute to the effect observed in the treated plants. In the present work, Trichormus sp., a native Chilean cyanobacterium isolated from drylands whose supernatants improved the cumulative germination and the shoot and root growth of native grass Polypogon australis, was selected. The observed effects were significant when compared with water a control but did not significantly differ when the BG-11 nutrient medium was used as a control. The nutrient content of Trichormus sp. supernatants was characterized throughout the growth phases of the culture on BG-11 medium, showing an important decrease in P (100 %) and Mn (84 %) content after the late exponential phase. Based on these results, a P and Mn-free BG-11 medium (BG-11 M) was prepared. In a bioassay with P. australis, the BG-11 M effect was compared with Trichormus sp. supernatants, which contained 40 % of P and 46 % of with respect to the original BG-11 medium. The results showed that the BG-11 M was less effective in promoting the shoot growth of P. australis than the supernatants, indicating that both elements, P and Mn, have a role in development of P. australis. We emphasize the need to consider the composition of nutrients remaining on culture medium when evaluating the effects of cyanobacterial cultures on plant growth and development.

Most Candida species are opportunistic pathogens with the ability to form biofilms, which increases their resistance to antifungal drug therapies and the host immune response. Essential oils (EOs) are an alternative for developing new antimicrobial drugs, due to their broad effect on cellular viability, cell communication, and metabolism. In this work, we evaluated the antifungal and antibiofilm potential of fifty EOs on C. albicans ATCC 10231, C. parapsilosis ATCC 22019, and Candida auris CDC B11903. The EOs’ antifungal activity was measured by means of a broth microdilution technique to determine the minimum inhibitory and fungicidal concentrations (MICs/MFCs) against the different Candida spp. strains. The effects on biofilm formation were determined by a crystal violet assay using 96-well round-bottom microplates incubated for 48 h at 35 °C. The EOs from Lippia alba (Verbenaceae family) carvone-limonene chemotype and L. origanoides exhibited the highest antifungal activity against C. auris. The L. origanoides EOs also presented antifungal and antibiofilm activity against all three Candida spp., thus representing a promising alternative for developing new antifungal products focused on yeast infections, especially those related to biofilm formation, virulence factors, and antimicrobial resistance.

Extended Abstract Phytoremediation technologies uses the ability of certain plants to absorb, accumulate, metabolize, volatilize or stabilize contaminants such as metals, that are present in the soil. Polypogon australis (Brong.) a native Chilean grass (Gramineae), is a facultative metallophyte that spontaneously colonizes abandoned mine tailing dumps. Genetic edition may be used to improve its metal tolerance and accumulation capabilities and thus to enhance its soil metal phytoextraction potential. At present, there are no protocols to carry out in vitro somatic embryogenesis and callus induction in P. australis which may lead to obtaining a complete gene-edited plant. In this study methodologies for massive in vitro plant tissue culture, callus formation and regeneration were studied by germinating and growing P. australis seeds in plates with Murashige and Skoog (MS) medium supplemented with sucrose and MS vitamins under controlled conditions (24°C, 4LS, 16/8; light/dark). A methodology for callus formation and plant tissue regeneration was carried out by cutting the seedlings in segments that were placed in plates with callus induction medium (CIM) and kept in darkness for 3 weeks, under control conditions (24°C, 0/24; light/dark). Results showed that both the medium and the growth conditions were effective for seed germination and early development of P. australis . A germination potential of 44-51% for P. australis seeds in the first 15 days was observed. After 7 days, callus development began only in the first segment corresponding to the hypocotyl. Therefore, for obtaining calluses of P. australis seedlings the optimal tissue was the hypocotyl. The percentage of callus formation was up to 38.9%.

Bacteria can communicate through quorum sensing, allowing them to develop different survival or virulence traits that lead to increased bacterial resistance against conventional antibiotic therapy. Here, fifteen essential oils (EOs) were investigated for their antimicrobial and anti-quorum-sensing activities using Chromobacterium violaceum CV026 as a model. All EOs were isolated from plant material via hydrodistillation and analyzed using GC/MS. In vitro antimicrobial activity was determined using the microdilution technique. Subinhibitory concentrations were used to determine anti-quorum-sensing activity by inhibition of violacein production. Finally, a possible mechanism of action for most bioactive EOs was determined using a metabolomic approach. Among the EOs evaluated, the EO from Lippia origanoides exhibited antimicrobial and anti-quorum activities at 0.37 and 0.15 mg/mL, respectively. Based on the experimental results, the antibiofilm activity of EO can be attributed to the blockage of tryptophan metabolism in the metabolic pathway of violacein synthesis. The metabolomic analyses made it possible to see effects mainly at the levels of tryptophan metabolism, nucleotide biosynthesis, arginine metabolism and vitamin biosynthesis. This allows us to highlight the EO of L. origanoides as a promising candidate for further studies in the design of antimicrobial compounds against bacterial resistance.

Plants growing in metal‐polluted sites can be a source of micro‐organisms suitable for bio‐assisted phytoremediation strategies. In this work, three endophytic fungi from the roots of Poa stuckertii and Poa pratensis, two grasses that naturally colonize a Lead‐Zinc tailing storage facility in Southern Chile, were isolated and identified. The leachate of the tailing sands showed a Pb content of 1·36 ± 0·71 ppm, and a pH of 7·3. By amplifying the ITS1/ITS4 region of fungal ribosomal DNA, the isolates were identified as Bjerkandera sp., Microdochium sp. and Sarocladium sp. When the growth media was supplemented with 50 ppm of Pb at pH 4·5, Microdochium sp. showed an 80% decrease in the biomass, but the biomass production of Bjerkandera sp. and Sarocladium sp. was not affected by the same treatment. The accumulation of Pb in Microdochium sp. increased as a function of the concentration of the metal in the growth media, between 48·3 and 241·3 μmol l−1. We showed that two Poaceae plants growing on a Lead‐Zinc tailing storage facility are a source of endophyte fungi and that Pb had a differential effect on the growth of the isolated fungi independent of the plant of origin.

Objective: To describe the prevalence of patients with mental disorders (MD) admitted to the ICU. To compare the clinical characteristics according to the presence of psychiatric history. To review the relevance of the consultations made to Psychiatry. Design: Retrospective descriptive study.Setting: ICU of the General Hospital of the Parc Sanitari Sant Joan de Deu, Sant Boi de Llobregat, Barcelona, Spain.Patients: Patients admitted between January 2016 and June 2018. Interventions: None.Main variables of interest: Severity level (APACHE II), reason for admission, days of admission, days of mechanical ventilation, psychiatric history and reason for psychiatric consultation.Results: A total of 1,247 patients were included; 194 (15.5%) met MD criteria, their mean age being younger (59 vs 68, P < .001) and with a lower mean score on the APACHE II scale (12 vs 14, P <= .003). There were 64 consultations to Psychiatry (5.1% of admissions), 59 of which were in patients with TM (92.1%). Regarding the reasons for the consultation, 22.6% were for attempted suicide, 61.3% for pharmacological adjustment, 11.3% to rule out mental disorder, and 4.8% for competence assessment. The probability of a consultation being carried out while it was indicated was 89.1%, while the probability of not carrying it out when it was not indicated was 99.4%.Conclusions: This study supports the need to expand the specific recommendations for consul-tation to Psychiatry, beyond the assessment after a suicide attempt, since a large percentage (77.5%) of the pertinent consultations were for other reasons.(c) 2021 Elsevier Espana, S.L.U. y SEMICYUC. All rights reserved.

Cyanobacteria are photoautotrophic organisms that inhabit diverse environments. Some species have been characterized for their production of extracellular polymeric substances (EPS) that have several biotechnological applications. EPS production is dependent on the growth conditions of the cyanobacteria, such as the content of nitrogen in the culture medium, the supplementation of the media with NaCl, or the light intensity. In this work, we studied the production profile of EPS at different growth stages in a culture from desert of the cyanobacterium Trichormus sp. The culture had been obtained from biological soil crusts (BSC) collected from a semi-arid zone of the IV region of Chile. We evaluated the effect of NaCl and nitrogen content in the culture media, in addition to the light intensity, on the growth and EPS production of the cyanobacterial cultures. The growth curve of Trichormus sp. showed a lag phase up to day 6, a short exponential phase up to day 10, and a stationary phase that lasted to the end of the experiment. The production of EPS was evaluated during the exponential growth phase of Trichormus sp. and showed a fourfold EPS production at 9.6 W m−2, compared to the basal condition at 3.2 W m−2. This light intensity is the highest light condition reported for the evaluation of EPS production in soil cyanobacteria. In this work, we show that the light intensity, but not the presence of NaCl or nitrogen in the medium, stimulates the production of EPS in the desert cyanobacterium Trichormus sp.

This study proposes a theoretical method based on DFT and COSMO-RS calculations to predict selectivity in the solvent extraction (SX) of lanthanum(III) and cerium(III), by using β-diketones as the extractant and kerosene or imidazolium-based ionic liquids (ILs) as the diluent. To calculate the selectivity, the model requires three important pieces of information: the extraction stoichiometry, the type and structure of the extractant/synergistic agent, and the diluent used in the SX process. Therefore, as the first step, the extraction stoichiometry is determined experimentally. Using these results to perform DFT and COSMO-RS calculations, thermochemical parameters allowed to calculate the selectivity. The results indicate that the theoretical selectivity trends agree closely with the experimental results even when using ILs as diluents, demonstrating the applicability of this method. It is established that the selectivity can be increased by using both β-diketones with bulky functional groups and a synergistic agent. This predictive method has immense potential as a practical tool providing valuable insights into the design of extractants and hydrophobic diluents for the selective recovery of lanthanides in industrial applications.

Lo que se discute en el marco de la idea “Chile, país minero”, es la necesidad de abrir el debate más allá de la visión sectorial y disciplinar, considerando la necesidad de lograr acuerdos entre los actores intervinientes directos e indirectos en la actividad extractiva. De modo que, al visualizar cómo la actividad minera se inserta en la dimensión local y regional, puedan minimizarse los impactos negativos de las distintas fases del ciclo minero dentro del modelo extractivista exportador, para desarrollar espacios de encuentro sobre las dimensiones involucradas por sobre los aspectos meramente productivos. Ello plantea la necesidad de un ordenamiento territorial, reconocimiento de otras ontologías y una distinta participación del Estado, que permita a todos los actores intervinientes monitorear el desempeño de la actividad minera, para que ésta alcance niveles de legitimidad en relación a consideraciones ambientales, los derechos de las personas, las comunidades y la opinión pública, en el marco de una reformulación de la cultura política, productiva, económica y ambiental.

The emergence of multidrug-resistant microorganisms represents a global challenge that has led to a search for new antimicrobial compounds. Essential oils (EOs) from medicinal aromatic plants are a potential alternative for conventional antibiotics. In this study, the antimicrobial and anti-biofilm potential of 15 EOs was evaluated on planktonic and biofilm-associated cells of Salmonella enterica serovar Enteritidis ATCC 13076 (S. enteritidis) and Salmonella enterica serovar Typhimurium ATCC 14028 (S. typhimurium). In total, 4 out of 15 EOs showed antimicrobial activity and 6 EOs showed anti-biofilm activity against both strains. The EO from the Lippia origanoides chemotype thymol-carvacrol II (LTC II) presented the lowest minimum inhibitory concentration (MIC50 = 0.37 mg mL−1) and minimum bactericidal concentration (MBC = 0.75 mg mL−1) values. This EO also presented the highest percentage of biofilm inhibition (>65%) on both microorganisms, which could be confirmed by scanning electron microscopy (SEM) images. Transcriptional analysis showed significant changes in the expression of the genes related to quorum sensing and the formation of the biofilm. EOs could inhibit the expression of genes involved in the quorum sensing mechanism (luxR, luxS, qseB, sdiA) and biofilm formation (csgA, csgB, csgD, flhD, fliZ, and motB), indicating their potential use as anti-biofilm antimicrobial agents. However, further studies are needed to elucidate the action mechanisms of essential oils on the bacterial cells under study.

In this work, the effect of different immobilization procedures on the properties of a lipase obtained from the extremophilic microorganism Serratia sp. USBA-GBX-513, which was isolated from Paramo soils of Los Nevados National Natural Park (Colombia), is reported. Different Shepharose beads were used: octyl-(OC), octyl-glyoxyl-(OC-GLX), cyanogen bromide (BrCN)-, and Q-Sepharose. The performance of the different immobilized extremophile lipase from Serratia (ESL) was compared with that of the lipase B from Candida antarctica (CALB). In all immobilization tests, hyperactivation of ESL was observed. The highest hyperactivation (10.3) was obtained by immobilization on the OC support. Subsequently, the thermal stability at pH 5, 7, and 9 and the stability in the presence of 50% (v/v) acetonitrile, 50% dioxane, and 50% tetrahydrofuran solvents at pH 7 and 40 °C were evaluated. ESL immobilized on octyl-Sepharose was the most stable biocatalyst at 90 °C and pH 9, while the most stable preparation at pH 5 was ESL immobilized on OC-GLX-Sepharose supports. Finally, in the presence of 50% (v/v) tetrahydrofuran (THF) or dioxane at 40 °C, ESL immobilized on OC-Sepharose was the most stable biocatalyst, while the immobilized preparation of ESL on Q-Sepharose was the most stable one in 40% (v/v) acetonitrile.

Biofilm as a cellular conformation confers survival properties to microbial populations and favors microbial resistance. Here, we investigated the antimicrobial, antibiofilm, antimotility, antihemolytic activity, and the interaction with synthetic membranes of 15 essential oils (EOs) on E. coli ATCC 25922 and S. aureus ATCC 29213. Antimicrobial activity of EOs was determined through microdilution method; development of the biofilm was assessed using the crystal violet assay and SEM microscopy. Results indicate that Lippia origanoides thymol–carvacrol II chemotype (LTC II) and Thymus vulgaris (TV) exhibited a significant antibacterial activity, with MIC values of 0.45 and 0.75 mg/mL, respectively. The percentage of biofilm formation inhibition was greater than 70% at subinhibitory concentrations (MIC50) for LTC II EO. The results demonstrate that these two oils had significantly reduced the hemolytic effect of S. aureus by 54% and 32%, respectively, and the mobility capacity by swimming in E. coli with percentages of decrease of 55% and 47%, respectively. The results show that LTC II and TV EOs can interact with the hydrophobic core of lipid bilayers and alter the physicochemical properties of membranes. The findings suggest that LTC II and TV oils may potentially be used to aid in the treatment of S. aureus and E. coli infections.

Antimicrobial peptides constitute an excellent alternative against conventional antibiotics because of their potent antimicrobial spectrum, unspecific action mechanism and low capacity to produce antibiotic resistance. However, a potential use of these biological molecules as therapeutic agents is threatened by their low stability and susceptibility to proteases. In order to overcome these limitations, encapsulation in biocompatible polymers as poly-lactic-glycolic-acid (PLGA) is a promising alternative for increasing their stability and bioavailability. In this work, the effect of new synthetic antimicrobial peptides GIBIM-P5S9K (G17) and GAM019 (G19) encapsulated on PLGA and acting against methicillin resistant Staphylococus aureus (MRSA) and Escherichia coli O157:H7 was studied. PLGA encapsulation allowed us to load around 7 µg AMPs/mg PLGA with an efficiency of 90.5%, capsule sizes around 290 nm and positive charges. Encapsulation improved antimicrobial activity, decreasing MIC50 from 1.5 to 0.2 (G17NP) and 0.7 (G19NP) µM against MRSA, and from 12.5 to 3.13 µM for E. coli O157:H7. Peptide loaded nanoparticles could be a bacteriostatic drug with potential application to treat these bacterial E. coli O157:H7 and MRSA infections, with a slow and gradual release.

The discussion about "Chile, mining country" is necessary to open the debate beyond the sectorial and disciplinary vision, and to consider the need of agreements between direct and indirect stakeholders involved in the extractive activity. The visualization of the mining activity inserted in the local and regional dimensions, can help to minimize the negative impacts of the mining cycle that is framed in an extractivist model for exportation. By doing this, it will be possible to foster meeting spaces about the involved dimensions beyond the merely productive aspects. Posing a territorial planning need, recognizing different ontologies and another State participation, the stakeholders could monitor the mining activities' performances. A mining industry that includes environmental aspects, the rights of people, communities and public opinion can be legitimized by a reformulation of the political, productive, economic and environmental culture.

This work presents the development of a prototype that allows identifying specific signs through artificial vision techniques. It uses an image segmentation stage based on the SLIC superpixel algorithm, followed by a sign recognition and classification stage based on convolutional neural networks and has been implemented in a simple-board computer (SBC). The prototype informs the user of the identification of these signs through an audio message sent to headphones, it has a GPS module that obtains the location where the sign was recognized and is stored to offer the user notifications about nearby signs. The tests were performed with 1: 2 scale signs in open spaces, with natural light. The prototype is intended as a support for visually impaired people to move in open urban environments. Processing times and prototype performance are reported. Although the implementation in the selected simple-board computer makes its use unfeasible due to operating times, the functionality of the system is demonstrated.