Extreme-halophiles: their role in the arsenic biogeochemical cycle

Biofilms, mats and microbialites dwell under extreme environmental conditions (high salinity, extreme aridity, pH and arsenic concentration) in the Argentinean Puna and the Atacama Desert. Microbial communities inhabiting those ecosystems are poorly known. Arsenic metabolism is proposed to be an ancient mechanism in microbial life. Besides, some bacteria and archaea are not only able to use detoxification processes to grow under high arsenic concentration, but also, some of them are able to exploit arsenic as a bioenergetic substrate in either anaerobic arsenate respiration or chemolithotrophic growth on arsenite. Only four aioAB coding for arsenite oxidase and two arrA coding for arsenate reductase sequences from haloarchaea were previously deposited in the NCBI Database, but have not been reported in the literature. The arrA arsenate reductases are reliable indicators of anaerobic As (V) respiration and catalyze the electron transfer to the As (V) terminal acceptor in dissimilatory arsenatereducing prokaryotes (DARPs). In this work, we are presenting our first steps in the study of the arsenic biogeochemical cycle in these ecosystems. Thus, the aim of this study was to isolate and to study the arsenic metabolism genes of the isolated extreme halophile microorganisms as well as to test the growth in minimal medium using different carbon sources. Mats and microbialites samples were taken from the water’s edge of Laguna Tebenquiche, Laguna Brava (Salar de Atacama, Chile) during December 2012 and from gaylusite crystals (Laguna Diamante) in August 2014. Samples were enriched and plated in WS medium supplemented with arsenic (AsIII 0.5mM and AsV 20mM). Arsenite oxidase (aioB) and Arsenate reductase (arrA) primers specific for haloarchaea were designed using PrimerProspector software. Selected primers were aioB-1190F (5’-GCTCMTSACCGGCAGCGTCG-3’), aioB-1507R (5’-YGATCTCGTCGATGTCGGCG-3’), arrA-417F (5’CCCGAGTTCGAGCCSATCTC-3’) and arrA-614R (5’GCRCAGATCGMGCTGTGGGA-3’). In order to identify the isolates we used Archaea-specific primers for 16S rDNA gene amplification: 344F (5´- ACG GGG YGC AGC AGG CGC GA-3´) and 915R (5´- GTG CTC CCC CGC CAA TTC CT -3´). Fragments of 577 bp, 317pb and 197pb were obtained from 16S rDNA, aioB and arrA genes respectively. Universal primers 27F and 1492R were used to amplify 16S rDNA in bacterial isolates. 25 isolates belonging to Archaea and Bacteria Domain were obtained; they are related to the Phylum Euryarchaeota, Firmicutes and Proteobacteria. AioB and arrA genes were found in most of the isolates and DNA from the samples (mats, microbialites and biofilm). The best carbon source tested was pyruvate and acetate, being pyruvate better in all cases. Promising results were obtained in the search of organisms able to use arsenic in their bioenergetic metabolism. More studies are underway to try to better understand these very interesting systems.Fil: Rasuk, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Soria, Mariana Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXI Congreso Argentino de Microbiología GeneralCordobaArgentinaSociedad Argentina de Microbiología Genera

The biofilms formation of exiguobacterium sp. S17 on synthetic supports and under the influence of arsenic

The high-altitude Andean Lakes (HAAL) areecosystems located in the South American Andes. These ecosystems are unique dueto their geographical characteristics, their broad range of extremeenvironments, as well their abundant biodiversity. Thegenus Exiguobacteriumis one of the most widespread and representative genera on the HAAL, beingdetected by direct (pure culture isolation) and indirect (DGGE) techniques. Thisgenera have been isolated or molecularly detected from a wide range of habitatsincluding cold and hot environments with temperature between-12 and 55°C. This fact confers substantial interest to the genus as apotential model system to research attributes that may correlate withadaptation and evolution of organisms to diverse thermalregimes. Exiguobacterium sp. S17 is a high arsenic resistantpolyextremophilic bacteria isolated from the stromatolites of L. Socompa. This strain is able to grow readily in laboratory and represents an attractive model system for the study of environmentalstress. Previous studies showed that Exiguobacterium sp. S17 is able to resistto high arsenic concentration and to produce biofilm. The aim of this work was toassess biofilms formation byExiguobacterium sp. S17 in different synthetic supports and to investigatethe influence of arsenic (As[III] y As[V]) in their development.Determination andquantification of biofilms was measured using crystal violet 1% following themethodology proposed by Tomaras et al., (2003). Biofilms production wasevaluated at different incubation times (24, 48 and 72 h) in LB50media (without As) and in different synthetic supports: sterile glass tubes (15x 125mm) and polypropylene (12 x 75 mm) and polystyrene plates (20 cm3).The influence of As was investigated supplemented LB50 with arsenate(As[V]): 50mM, 100 mM, 150 mM, 200mM, 250mM and arsenite (As[III]): 2.5 mM,5mM, 7.5 mM, 10 mM, 12.5 mM at the same time.ANOVA analyzes revealed that the optimal production of biofilms isachieved after 24 hours of growth and the highest biofilm production wasobtained when using glass as support and adding  arsenate (As [V]100 mM). No significant differences were observed when adding arsenite in comparison tocontrol medium (without arsenic).The findings obtained in this work made an important contribution to theknowledge of the biology and ecology of the microbial communities of the HAALin response to stress factors. Moreover, this method can be applied for thebenefit of human and environmental health by establishing an experimental basisfor a bioremediation method. Furthermore, we propose that HAAL is a source of novelbacterial species of biotechnological interest.Fil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Zannier, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Albarracín, Virginia Helena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaXI Congreso argentino de Microbiología GeneralCordobaArgentinaSociedad Argentina de Microbiología Genera

Respuesta de Exiguobacterium sp a radiación ultravioleta artificial, aislados de Lagunas de Altura del Noroeste Argentino

Las lagunas de altura de la Puna y cordillera del NOA se encuentran ubicadas a más de 3.800 m.s.n.m., se tratan de ambientes prístinos, inexplorados, de difícil acceso para el hombre y expuestos a condiciones extremas tales como alta salinidad, radiación ultravioleta (RUV), bajo contenido de fósforo, gran amplitud térmica, alto contenido de metales pesados, etc. Estas características hacen de ellas un escenario particularmente interesante para llevar a cabo estudios de resistencias a RUV-B. Fue investigado el efecto de la radiación ultravioleta-B (RUV-B) en la sobrevida de Exiguobacterium sp., una bacteria Gram positive, aislada de Laguna Negra, ubicada en la Puna del Noroeste Argentino, a mas de 4.000 metros sobre el nivel de mar (m.s.n.m.) con un maximo de irradiancía registrado de 10.80 Wm2. Los perfiles de resistencia a RUV-B fueron comparados con una cepa de colección del genero Exiguobacterium arantiacum DSMZ 6208; y con las muestras colectadas, se realizo electroforesis en gel de dos dimensiones.Fil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Cortez, Nestor Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaPrimera Reunión de Fotobiólogos Moleculares ArgentinosLa PlataArgentinaConsejo Nacional de Investigaciones Científicas y TécnicasUniversidad Nacional de La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

High-Up: A Remote Reservoir of Microbial Extremophiles in Central Andean Wetlands

The Central Andes region displays unexplored ecosystems of shallow lakes and salt flats at mean altitudes of 3700 m. Being isolated and hostile, these so-called “High-Altitude Andean Lakes” (HAAL) are pristine and have been exposed to little human influence. HAAL proved to be a rich source of microbes showing interesting adaptations to life in extreme settings (poly-extremophiles) such as alkalinity, high concentrations of arsenic and dissolved salts, intense dryness, large daily ambient thermal amplitude, and extreme solar radiation levels. This work reviews HAAL microbiodiversity, taking into account different microbial niches, such as plankton, benthos, microbial mats and microbialites. The modern stromatolites and other microbialites discovered recently at HAAL are highlighted, as they provide unique modern—though quite imperfect—analogs of environments proxy for an earlier time in Earth's history (volcanic setting and profuse hydrothermal activity, low atmospheric O2 pressure, thin ozone layer and high UV exposure). Likewise, we stress the importance of HAAL microbes as model poly-extremophiles in the study of the molecular mechanisms underlying their resistance ability against UV and toxic or deleterious chemicals using genome mining and functional genomics. In future research directions, it will be necessary to exploit the full potential of HAAL poly-extremophiles in terms of their biotechnological applications. Current projects heading this way have yielded detailed molecular information and functional proof on novel extremoenzymes: i.e., DNA repair enzymes and arsenic efflux pumps for which medical and bioremediation applications, respectively, are envisaged. But still, much effort is required to unravel novel functions for this and other molecules that dwell in a unique biological treasure despite its being hidden high up, in the remote Andes.Fil: Albarracín, Virginia Helena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Belfiore, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; ArgentinaFil: Luccini, Eduardo Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Facultad de Química e Ingeniería-Rosario; ArgentinaFil: Salum, Graciela Marisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; ArgentinaFil: Piacentini, Ruben Dario Narciso. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Física de Rosario. Universidad Nacional de Rosario. Instituto de Física de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, Ingeniería y Agrimensura; Argentina. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentin

Genome sequence analysis of bacteria highly tolerant to arsenic, isolated from High Altitude Andean Lakes (HAAL)

High Altitude Andean lakes (HAAL) comprise a system of shallow lakes formed during the tertiary period (1.8-65 million years ago) distributed across the Puna (high plateau) at altitudes varying from 4,200 m to 6,000 m above sea level (asl). These aquatic ecosystems present extreme environmental conditions such as high levels of Ultraviolet Radiation (UVR), a wide range of salinity (from 0.4 to 117 ppm), large daily temperature fluctuations ranging from 20° C to -40° C, low nutrient concentrations and the presence of heavy metals and metaloids, mainly arsenic. The presence of arsenic resistance mechanisms has been explored in several microbiological studies in arsenic-rich environments. The most characterized arsenic resistance mechanism is the ars operon located either in plasmids or chromosomes of prokaryotes. Bacterial As detoxification involves the reduction of arsenate (As[V]) to arsenite (As[III]) via a cytoplasmic arsenate reductase (arsC). Later on As[III] will be extruded by a membrane-associated ArsB efflux pump. Other genes like arsR, arsD and arsA form part of ars operon along with arsB and arsC in most of the As tolerant prokaryotes. HAAL isolates show enhanced resistance compared to other bacteria carrying the ars operon. This could be explained by the presence of additional genes related to this function, including extra copies of the ars operon or supplementary extrusion pumps. The aim of this study was to elucidate the genetic mechanisms of tolerance to high arsenic concentrations, taking advantage of the available genomes of three UV resistant bacterial strains, recently isolated from HAAL extreme environments. Moreover, the presence of the ACR3 gene as a possible resistance mechanism was assessed by degenerate oligonucleotides. We studied the strains Acinetobacter sp. Ver3 and Exiguobacterium sp. N30 and S17, isolated from shallow water (Laguna Verde and Laguna Negra), and from modern stromatolites (in Laguna Socompa) respectively. Maximal arsenic concentration was 33.81 mg/L. Genome sequences were obtained using a whole-genome shotgun strategy with a 454 GS Titanium pyrosequencer at INDEAR, Argentina. Genomes were annotated and analyzed in the RAST annotation server. PSI-BLAST and ClustalW were used to compare and align sequences, and phylogenetic trees were built using Mega5. The effect of As[V] and As[III] during growth in rich media was also evaluated by different protocols. The strains Exiguobacterium arantiacum DSMZ 6208 and Acinetobacter baumannii DSM 30007 were used as controls during tolerance profiles measurements. Organisms with high tolerance to this metalloid, isolated in pure culture from environments such as HAAL, could be good candidates for studies of bioremediation of metals and metalloids, a methodology considered of low cost and environmentally friendly.Fil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Kurth, Daniel German. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Turjanski, Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química Biológica de la Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Vázquez, Martin. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto de Agrobiotecnología de Rosario; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Cortez, Nestor Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Biología Molecular y Celular de Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Biología Molecular y Celular de Rosario; ArgentinaVIII Congreso argentino de Microbiología GeneralMar del PlataArgentinaSociedad Argentina de Microbiología Genera

Bacteriorodhopsin or arsenite as energy source in the growth of haloarchaea

Laguna Diamante (S 26°1’50’’ O 67°2’32’’) ubicada en el cráter del volcán Galán en Catamarca, a 4750 m. s.n.m., presenta condiciones extremas como: elevado pH, salinidad, alta radiación ultravioleta (UV) y alto contenido de metales pesados y metaloides, principalmente arsénico (As) [1], el cuál es un compuesto altamente tóxico y muy distribuido en la corteza terrestre [2]. En este ambiente, han sido reportadas unas biopelículas rojas (BD) formadas en la parte inferior de microbialitos de tipo leiolitos, y los estudios metagenómicos demostraron que están constituidas por un 94% de haloarqueas [1]. Algunas haloarqueas presentan un mecanismo fotosintético que les permite producir ATP de una forma similar al realizado en la cadena transportadora, pero a diferencia de ésta, los protones expulsados no provienen de complejos proteicos sino de una bomba de protones fotoexitable, la “bacteriorrodopsina” (BR) [3]. Mecanismo que les permite enfrentar las bajas concentraciones de oxígeno de ambientes hipersalinos. Objetivo: estudiar la influencia de la luz en el crecimiento microbiano de haloarqueas aisladas de BD en presencia y ausencia de arsenito (As III). Para ello, se utilizaron cinco haloarqueas aisladas de BD del género Halorubrum (DM1, DM2, DM3, DM4 y DM5) para evaluar su crecimiento en medio mínimo (CDM con piruvato como fuente de carbono [5]) con y sin adición de AsIII (1 mM de concentración final); usando el medio de aislamiento WJK [4] como control. Los cultivos fueron incubados a 37 °C y agitados a 120 r.p.m. entre 7 – 10 días (dependiendo del tiempo de generación de la cepa) midiendo la densidad óptica (Do) a 600 nm cada 12 h. Se utilizaron dos condiciones: luz blanca fría (400 – 700 nm) y oscuridad (cubriendo los frascos con láminas de aluminio). Se observó que de las cepas estudiadas, DM2 presentó un mayor crecimiento en CDM con As III en oscuridad, mientras que en luz el mejor crecimiento fue observado en CDM sin la adición de As III, en el resto de las condiciones el crecimiento fue escaso. A partir de estos resultados obtenidos se sugiere que en presencia de luz DM2 utilizaría el sistema de la bacteriorodopsina para obtener energía y sostener su crecimiento, mientras que en oscuridad la obtención de energía sería a través del uso del As III como donador de electrones.Fil: Soria, Mariana Noelia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Rasuk, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Ordoñez, Omar Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaFil: Farias, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Planta Piloto de Procesos Industriales Microbiológicos; ArgentinaIII Reunión de Fotobiólogos Moleculares ArgentinosSan Miguel de TucumánArgentinaGrupo Argentino de Fotobiologí

Abonemos orgánicamente el futuro

El proyecto Abonemos Orgánicamente el futuro, surge de la necesidad de buscar alternativas de solución frente a la falta de sensibilidad, conocimiento y responsabilidad acerca de los efectos de los abonos y fungicidas químicos en el ambiente. La implementación de estos proyectos pretende convertir a cada persona en un agente activo esencial dentro del proceso de conservación del ambiente, presentando como alternativa el cambio progresivo en las prácticas agrícolas en cuanto al empleo de abonos y fungicidas químicos por abonos y fungicidas orgánicos aprovechando los recursos que se encuentren en el entorno

La Imagen y la Narrativa como Herramientas para el Abordaje Psicosocial en Escenarios de Violencia. Departamento Risaralda, Valle y Caldas.

La Imagen y la Narrativa como Herramientas para el Abordaje Psicosocial en Escenarios de Violencia. Departamento Risaralda, Valle y Caldas.Cada relato expuesto, es una radiografía de los diferentes tipos de violencia que se viven en Colombia por más de medio siglo, partiendo del análisis de las subjetividades inmersas en los contextos de violencia, representados en diferentes zonas del país y enmarcados en cada uno de los cinco relatos expuesto. Cada uno, nos muestran las consecuencias a nivel social, económico, político, cultural y personal, reflejado en los protagonistas que describen en sus historias, a través de su propia narrativa, cómo han sido las consecuencias reflejadas en el abuso, el desplazamiento, el secuestro, la violación a los derechos humanos, la inseguridad, la pobreza, el narcotráfico, el desempleo y el desarraigo de su comunidad. Como eje del análisis grupal, se seleccionó el relato N. 2 “Camilo”, enmarcado en la violencia que se ha ensañado contra los jóvenes del país, reflejada en sucesos que van desencadenando hechos de violencia, donde se ve reflejada la injusticia y la desigualdad como denominador de las circunstancias que se expone en su narrativa. Se puede resaltar: la discriminación racial, su condición de desplazado, su desarraigo de identidad, así como su posición resiliente la cual permite hacer procesos de aceptación y de superación de cada una de las adversidades que ha vivido, enfrentando nuevos retos que lo han fortalecido en su proceso formativo y su capacidad de empoderamiento para crecer como individuo y generar nuevas oportunidades de vida. Es importante analizar los factores psicosociales que lo han afectado como sobreviviente de la violencia y lo han marcado, como también poder superar las dificultades y a partir de un proyecto de vida como este, puede contribuir desde su experiencia a su comunidad. A partir del estudio relacionado con la incursión dada en la cuenca del Cacarica, se presentan varias propuestas de intervención psicosocial para contribuir a mejorar las condiciones y la transformación de los hechos violentos que se presentaron contra la población civil y de esta forma promover la reconstrucción de la memoria histórica y hacer parte del proceso de reparación del tejido social de la comunidad.Each exposed story is an x-ray of the different types of violence that have been lived in Colombia for more than half century, based on the analysis of subjectivities immersed in the contexts of violence, represented in different regions of the country and framed in each of the five stories exposed. Each one shows us the consequences at the social, economic, political, cultural and personal level, reflected in the protagonists they describe in their stories, through their own narrative, how the consequences have been reflected in abuse, displacement, kidnapping, violence against human rights, insecurity, poverty, drug trafficking, unemployment and uprooting from their community. As the focus of the group analysis, we select the story N. 2 “Camilo”, framed in the violence that has been taught against the youth of the country, reflected in events that are triggering acts of violence, where injustice and inequality are reflected as denominator of the circumstances that exposes us in his narrative. We can highlight: racial discrimination, his condition as a homeless person, his uprooting identity, as well as his resilient position which allows the acceptance and overcoming of each one of the adversities he has lived through, facing new challenges that have strengthened him in its formative process and its empowerment capacity to grow as an individual and generate new life opportunities. It is important to analyze the psychosocial factors that have affected him as a survivor of violence and have marked him, as well as being able to overcome difficulties and from a life project like this, he can contribute from his experience to his community. From the study related to the incursion in the Cacarica basin, several proposals for psychosocial intervention are presented to help improve the conditions and transformation of the violent events that were filed against the civilian population and thus promote the reconstruction of the historical memory of the community and take part of the social repairing process of the community

Post‐epizootic microbiome associations across communities of neotropical amphibians

Microbiome–pathogen interactions are increasingly recognized as an important element of host immunity. While these host-level interactions will have consequences for community disease dynamics, the factors which influence host microbiomes at larger scales are poorly understood. We here describe landscape-scale pathogen–microbiome associations within the context of post-epizootic amphibian chytridiomycosis, a disease caused by the panzootic chytrid fungus Batrachochytrium dendrobatidis. We undertook a survey of Neotropical amphibians across altitudinal gradients in Ecuador ~30 years following the observed amphibian declines and collected skin swab-samples which were metabarcoded using both fungal (ITS-2) and bacterial (r16S) amplicons. The data revealed marked variation in patterns of both B. dendrobatidis infection and microbiome structure that are associated with host life history. Stream breeding amphibians were most likely to be infected with B. dendrobatidis. This increased probability of infection was further associated with increased abundance and diversity of non-Batrachochytrium chytrid fungi in the skin and environmental microbiome. We also show that increased alpha diversity and the relative abundance of fungi are lower in the skin microbiome of adult stream amphibians compared to adult pond-breeding amphibians, an association not seen for bacteria. Finally, stream tadpoles exhibit lower proportions of predicted protective microbial taxa than pond tadpoles, suggesting reduced biotic resistance. Our analyses show that host breeding ecology strongly shapes pathogen–microbiome associations at a landscape scale, a trait that may influence resilience in the face of emerging infectious diseases.info:eu-repo/semantics/publishedVersio

Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide