Características físicas, químicas y microbiológicas del agua subterránea en Los Chiles, Costa Rica, y su asociación con el uso del suelo

“Physical, chemical, and microbiological characteristics of groundwater in Los Chiles, Costa Rica, and its association with land use”. Introduction: Los Chiles has one of the lowest Social Progress Indexes in Costa Rica. The inhabitants drink untreated groundwater from an aquifer across the Nicaragua-Costa Rica border. Objective: To characterize water quality and possible associations with land use. Methods: We collected six water samples from wells during the dry and rainy seasons in 2019 and applied standard tests. Results: Grasslands and bare ground cover larger areas than other land uses. The water is calcic-bicarbonate type, and its physical-chemical values are acceptable, we did not detect Escherichia coli in any sample, while we only detected fecal coliforms in La Trocha. Conclusion: If treated to eliminate coliforms and protected from other effects of human activity, this water will be optimal for human consumption.Introducción: Los Chiles tiene uno de los índices de progreso social más bajos de Costa Rica. Los habitantes beben agua subterránea no tratada de un acuífero que atraviesa la frontera entre Nicaragua y Costa Rica. Objetivo: Caracterizar la calidad del agua y posibles asociaciones con el uso de la tierra. Métodos: Recolectamos seis muestras de agua de pozos durante las temporadas seca y lluviosa en 2019 y aplicamos pruebas estándar. Resultados: Los pastizales y el suelo descubierto cubren áreas más grandes que otros usos del suelo. El agua es del tipo calcio-bicarbonato, y sus valores físico-químicos son aceptables, no detectamos Escherichia coli en ninguna muestra, mientras que coliformes fecales sólo en La Trocha. Conclusión: Si se trata para eliminar los coliformes y se protege de otros efectos de la actividad humana, esta fuente será óptima para el consumo humano

Contaminación del agua del río Durazno, Costa Rica: más allá del índice holandés de calidad del agua

ABSTRACT. “Pollution of the Durazno River water, Costa Rica: beyond the Dutch water quality index”. Introduction: The micro-basin of the Durazno River in Costa Rica is a source of water for human consumption, but is suspected of microbiological pollution from several land uses. Objective: To assess the water quality of the Durazno micro-basin from the physicochemical, microbiological and antibiotics points of view. Methods: We used the Dutch Water Quality index; Standard Methods for the Examination of Water and Wastewater; and solid-phase extraction and ultra-high performance liquid chromatography coupled to tandem mass spectrometry. Results: While physicochemical parameters indicated an adequate water quality, microbiologically this water is not acceptable for human consumption. The water has Doxycycline and Cefotaxime, possibly of agricultural origin. This is the first report of Cefotaxime in water from Costa Rica. The Dutch index fails to take into account microbiological parameters that are also important. Conclusion: The Durazno River does not meet the standards for human water consumption and the Dutch index needs to be complemented with microbiological parameters.    RESUMEN. Introducción: La microcuenca del río Durazno en Costa Rica es fuente de agua para consumo humano, pero se sospecha de contaminación microbiológica por varios usos del suelo. Objetivo: Evaluar la calidad del agua de la microcuenca del Durazno desde el punto de vista fisicoquímico, microbiológico y antibiótico. Métodos: Utilizamos el índice holandés de calidad del agua; Métodos Estándar para el Examen de Agua y Aguas Residuales; y extracción en fase sólida y cromatografía líquida de ultra alta resolución con espectrometría de masas en tándem. Resultados: Si bien los parámetros fisicoquímicos indicaron una calidad de agua adecuada, microbiológicamente esta agua no es aceptable para el consumo humano. El agua tiene doxiciclina y cefotaxima, posiblemente de origen agrícola. Este es el primer reporte de Cefotaxima en agua de Costa Rica. El índice holandés no tiene en cuenta parámetros microbiológicos que también son importantes. Conclusión: El río Durazno no cumple con los estándares para consumo humano de agua y el índice holandés necesita ser complementado con parámetros microbiológicos

Contaminación del agua del río Durazno, Costa Rica: más allá del índice holandés de calidad del agua

RESUMEN. Introducción: La microcuenca del río Durazno en Costa Rica es fuente de agua para consumo humano, pero se sospecha de contaminación microbiológica por varios usos del suelo. Objetivo: Evaluar la calidad del agua de la microcuenca del Durazno desde el punto de vista fisicoquímico, microbiológico y antibiótico. Métodos: Utilizamos el índice holandés de calidad del agua; Métodos Estándar para el Examen de Agua y Aguas Residuales; y extracción en fase sólida y cromatografía líquida de ultra alta resolución con espectrometría de masas en tándem. Resultados: Si bien los parámetros fisicoquímicos indicaron una calidad de agua adecuada, microbiológicamente esta agua no es aceptable para el consumo humano. El agua tiene doxiciclina y cefotaxima, posiblemente de origen agrícola. Este es el primer reporte de Cefotaxima en agua de Costa Rica. El índice holandés no tiene en cuenta parámetros microbiológicos que también son importantes. Conclusión: El río Durazno no cumple con los estándares para consumo humano de agua y el índice holandés necesita ser complementado con parámetros microbiológicos

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Microorganismos electroactivos en el agua residual de beneficiado de café (procesos redox de hierro)

Introducción: Las aguas residuales a menudo son una buena fuente de bacterias electrogénicas, esenciales para las Celdas Microbianas de Combustible (CMC). Los electrones que liberan al metabolizar la materia orgánica son evidencia de su capacidad electrogénica. Objetivo: Evaluar la capacidad de reducción de hierro de las bacterias aisladas de las aguas residuales del café. Métodos: Aislamos del electrodo del ánodo de las CMC bacterias facultativas morfológicamente diferentes, utilizando agua residual de un beneficio de café como sustrato. A estas bacterias les realizamos una identificación preliminar por el sistema Biolog GEN III (Biolog Inc. Hayward, CA, EE. UU.). Determinamos el porcentaje de conversión de    a  por parte de las bacterias aisladas en citrato de hierro (III), cloruro de hierro (III) y óxido de hierro (III); empleamos Shewanella oneidensis como control positivo en los ensayos. Resultados: Obtuvimos ocho aislamientos bacterianos con predominancia de morfología de bacilos Gram positivos no esporulados. Hubo actividad reductiva en los compuestos de hierro, con mejores porcentajes de conversión de  a   en el óxido de hierro (III). El aislamiento coincidente con el género Citrobacter (SB), único bacilo Gram negativo, tuvo porcentajes de conversión de hierro superiores a 1,0% en los tres compuestos de hierro (máximo 4,3%). Conclusión: En el agua residual del proceso de café, existen bacterias con capacidad electrogénica que podrían utilizarse en Celdas Microbianas de Combustible

Tolerance and sorption of Bromacil and Paraquat by thermophilic cyanobacteria Leptolyngbya 7M from Costa Rican thermal springs

We studied the adsorption ability and tolerance of the thermophilic filamentous cyanobacteria Letolyngbya 7M towards Paraquat and Bromacil. Adsorption isotherms at pH = 7.0 showed an adsorption capacity of 24.4 mg/g and 66.8 mg/g, respectively, and a good fit to the Langmuir model (R2 = 0.97 and 0.99, respectively). To evaluate the effect of both herbicides on photosynthetic pigments and viability of cyanobacteria, cell autoflorescence and esterase activity was determined using flow cytometry. Autofluorescence was less sensitive to changes in cell viability, as it was only slightly reduced at high Paraquat and Bromacil concentrations. Herbicide effect on esterase activity is dose-dependent. Bromacil did not cause a significant effect on either chlorophyll a content or cell viability. This study demonstrates the potential of Leptolyngbya 7M to remove Paraquat and Bromacil herbicides from aqueous solution under laboratory conditions.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biología Celular y Molecular (CIBCM

Biogas Production and Microbial Communities of Mesophilic and Thermophilic Anaerobic Co-Digestion of Animal Manures and Food Wastes in Costa Rica

Biomass generated from agricultural operations in Costa Rica represents an untapped renewable resource for bioenergy generation. This study investigated the effects of two temperatures and three mixture ratios of manures and food wastes on biogas production and microbial community structure. Increasing the amount of fruit and restaurant wastes in the feed mixture significantly enhanced the productivity of the systems (16% increase in the mesophilic systems and 41% in the thermophilic). The methane content of biogas was also favored at higher temperatures. Beta diversity analysis, based on high-throughput sequencing of 16S rRNA gene, showed that microbial communities of the thermophilic digestions were more similar to each other than the mesophilic digestions. Species richness of the thermophilic digestions was significantly greater than the corresponding mesophilic digestions (F = 40.08, p = 0.003). The mesophilic digesters were dominated by Firmicutes and Bacteroidetes while in thermophilic digesters, the phyla Firmicutes and Chloroflexi accounted for up to 90% of all sequences. Methanosarcina represented the key methanogen and was more abundant in thermophilic digestions. These results demonstrate that increasing digestion temperature and adding food wastes can alleviate the negative impact of low C:N ratios on anaerobic digestion

C1 compounds shape the microbial community of an abandoned century-old oil exploration well

The search for microorganisms that degrade hydrocarbons is highly relevant because it enables the bioremediation of these substances cheaply and without dangerous by-products. In this work, we studied the microbial communities of an exploratory oil well, abandoned a century ago, located in the Cahuita National Park of Costa Rica. Cahuita well is characterized by a continuous efflux of methane and the presence of a mixture of hydrocarbons including C2-dibenzothiophene, phenanthrene or anthracene, fluoranthene pyrene, dibenzothiophene, tricyclic terpanes, pyrene, sesquiterpenes, sterane and n-alkanes. Based on the analysis of 16S rRNA gene amplicons, we detected a significant abundance of methylotrophic bacteria (Methylobacillus (6.3-26.0 % of total reads) and Methylococcus (4.1-30.6 %)) and the presence of common genera associated with hydrocarbon degradation, such as Comamonas (0.8-4.6 %), Hydrogenophaga (1.5-3.3 %) Rhodobacter (1.0-4.9 %) and Flavobacterium (1.1-6.5 %). We evidenced the presence of methane monooxygenase (MMO) activities, responsible for the first step in methane metabolism, by amplifying the pmo gene from environmental DNA. We also isolated a strain of Methylorubrum rhodesianum, which was capable of using methanol as its sole carbon source. This work represents a contribution to the understanding of the ecology of communities of microorganisms in environments with permanently high concentrations of methane and hydrocarbons, which also has biotechnological implications for the bioremediation of highly polluting petroleum components.Universidad de Costa Rica/[809-B8-518]/UCR/Costa RicaNacional de Innovaciones Biotecnológicas/[]/CENIBiot/Costa RicaGobierno de Chile/[ANID PIA/Anillo ACT172128]//ChileGobierno de Chile/[ANID PIA/BASAL FB0002 ]//ChileFondo Nacional de Desarrollo Científico y Tecnológico/[1201741]/FONDECYT/ChileUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Electroquímica y Energía Química (CELEQ)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologíaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Químic

The putative phosphate transporter PitB (PP1373) is involved in tellurite uptake in Pseudomonas putida KT2440

Tellurium oxyanions are chemical species of great toxicity and their presence in the environment has increased because of mining industries and photovoltaic and electronic waste. Recovery strategies for this metalloid that are based on micro-organisms are of interest, but further studies of the transport systems and enzymes responsible for implementing tellurium transformations are required because many mechanisms remain unknown. Here, we investigated the involvement in tellurite uptake of the putative phosphate transporter PitB (PP1373) in soil bacterium Pseudomonas putida KT2440. For this purpose, through a method based on the CRISPR/Cas9 system, we generated a strain deficient in the pitB gene and characterized its phenotype on exposing it to varied concentrations of tellurite. Growth curves and transmission electronic microscopy experiments for the wild-type and ΔpitB strains showed that both were able to internalize tellurite into the cytoplasm and reduce the oxyanion to black nano-sized and rod-shaped tellurium particles, although the ΔpitB strain showed an increased resistance to the tellurite toxic effects. At a concentration of 100 μM tellurite, where the biomass formation of the wild-type strain decreased by half, we observed a greater ability of ΔpitB to reduce this oxyanion with respect to the wild-type strain (~38 vs ~16 %), which is related to the greater biomass production of ΔpitB and not to a greater consumption of tellurite per cell. The phenotype of the mutant was restored on over-expressing pitB in trans. In summary, our results indicate that PitB is one of several transporters responsible for tellurite uptake in P. putida KT2440.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA

Methylotrophs and Hydrocarbon-Degrading Bacteria Are Key Players in the Microbial Community of an Abandoned Century-Old Oil Exploration Well

In this work, we studied the microbial community and the physicochemical conditions prevailing in an exploratory oil well, abandoned a century ago, located in the Cahuita National Park (Costa Rica). According to our analysis, Cahuita well is characterized by a continuous efflux of methane and the presence of a mixture of hydrocarbons including phenanthrene/anthracene, fluoranthene, pyrene, dibenzothiophene, tricyclic terpanes, pyrene, sesquiterpenes, sterane, and n-alkanes. Based on the analysis of 16S rRNA gene amplicons, we detected a significant abundance of methylotrophic bacteria such as Methylobacillus (6.3–26.0% of total reads) and Methylococcus (4.1–30.6%) and the presence of common genera associated with hydrocarbon degradation, such as Comamonas (0.8–4.6%), Hydrogenophaga (1.5–3.3%) Rhodobacter (1.0–4.9%), and Flavobacterium (1.1–6.5%). The importance of C1 metabolism in this niche was confirmed by amplifying the methane monooxygenase (MMO)–encoding gene (pmo) from environmental DNA and the isolation of two strains closely related to Methylorubrum rhodesianum and Paracoccus communis with the ability to growth using methanol and formate as sole carbon source respectively. In addition, we were able to isolated 20 bacterial strains from the genera Pseudomonas, Acinetobacter, and Microbacterium which showed the capability to grow using the hydrocarbons detected in the oil well as sole carbon source. This work describes the physicochemical properties and microbiota of an environment exposed to hydrocarbons for 100 years, and it not only represents a contribution to the understanding of microbial communities in environments with permanently high concentrations of these compounds but also has biotechnological implications for bioremediation of petroleum-polluted sites.Universidad de Costa Rica/[809-B8-518]/UCR/Costa RicaCentro Nacional de Innovaciones Biotecnológicas/[ACT172128]/CENIBiot/Costa RicaAgencia Nacional de Investigación y Desarrollo/[FB0002]/ANID/ChileFondo Nacional de Desarrollo Científico y Tecnológico/[1201741]/FONDECYT/ChileUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Electroquímica y Energía Química (CELEQ)UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de QuímicaUCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biologí