Artículos científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14755

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Mostrando 1 - 9 de 9

A multidisciplinary approach to analyze the antimicrobial resistance in natural ecosystems
(Universidad Nacional, Costa Rica, 2024-02-25) Blanco-Pena, K; Quesada-Alvarado, Francisco; Salas-González, Denis; Chaverri-Fonseca, Fabio
Antimicrobial Resistance (AMR) poses a global threat to both human health and environmental well-being. Our study delved into Costa Rican wildlife reserves, uncovering a substantial human impact on these ecosystems and underscoring the imperative to pinpoint AMR hotspots. Embracing a One Health perspective, we advocated for a comprehensive landscape analysis that intricately intertwined geographic, climatic, forest, and human factors. This study illuminated the link between laboratory results and observed patterns of antimicrobial use, thereby paving the way for sustainable solutions. Our innovative methodology involved deploying open-ended questions to explore antimicrobial usage across livestock activities, contributing to establishing a comprehensive methodology. Non-invasive sampling in wildlife emerged as a critical aspect, shedding light on areas contaminated by AMR. Feline species, positioned at the apex of the food chain, acted as sentinels for environmental health due to heightened exposure to improperly disposed waste. Regarding laboratory findings, each sample revealed the presence of at least one antimicrobial resistance gene (ARG). Notably, genes encoding resistance to tetracyclines dominated (94.9%), followed by beta-lactams (75.6%), sulfonamides (53.8%), aminoglycosides (51.3%), quinolones (44.9%), phenicols (25.6%), and macrolides (20.5%). Genes encoding polymyxins were not detected. Moreover, 66% of samples carried a multi-resistant microbiome, with 15% exhibiting resistance to three antimicrobial families and 51% to four. The absence of a correlation between forest coverage and ARG presence underscored the profound human impact on wildlife reserves, surpassing previous estimations. This environmental pressure could potentially modify microbiomes and resistomes in unknown ways. As not all antimicrobial families encoding ARGs were utilized by farmers, our next step involved evaluating other human activities to identify the primary sources of contamination. This comprehensive study contributed crucial insights into the intricate dynamics of AMR in natural ecosystems, paving the way for targeted interventions and sustainable coexistence.
Assessing habitat selection in the prawn Macrobrachium rosenbergii using the model toxicant copper and colonization as a test endpoint: Does prior exposure determine biochemical and behavioral responses?
(Universidad Nacional, Costa Rica, 2024-08-20) Mena, F; Echeverría-Sáenz, Silvia; Brenes-Bravo, Gabriel; Araújo, Cristiano VM; Moreira-Santos, Matilde
Habitat selection by aquatic organisms is dependent on the availability of adequate conditions to support life and the benefits that the habitat provides. Contaminated environments tend to be less attractive to organisms because reduced habitat quality leads to increased maintenance costs. Consequently, reduced colonization of such disturbed habitats is an expected response. However, colonization has been understudied as an ecotoxicological test endpoint, despite its proven ability to assess habitat selection by populations across various taxa. The aim of the present study was to investigate whether previous exposure to copper could alter the colonization behavior of the freshwater prawn Macrobrachium rosenbergii along a non-forced exposure gradient of interconnected copper- contaminated habitats (0 to 500 µg/L) due to physiological and behavioral impairments. To assess this, post- larvae of M. rosenbergii were pre-exposed to 0, 50, 250 and 500 µg/L copper for a maximum period of 48 h. The physiological status and motility of the organisms after pre-exposure to copper were evaluated using behavioral endpoints (swimming activity by video tracking) and biochemical biomarkers (biotransformation, oxidative stress and neurotoxicity). The results indicated that pre-exposure to copper (at concentrations of 0, 50 and 500 µg/L) significantly influenced the median colonization concentration (CC50), which decreased from 270 µg/L to 109 µg/L. None of the assessed swimming parameters (speed, motility rate, exploration rate, and total distance) were affected by the pre-exposure to copper (0, 50 and 250 µg/L). Biochemically, cholinesterase levels were only affected in the prawn population exposed to 250 µg/L of copper. The present study provides a better understanding of the relevance of colonization as an ecotoxicological endpoint for assessing the spatial distribution of populations, including both new inhabitants and previously exposed organisms, in recovering habitats.
Bacterial communities in residential wastewater treatmentplants are physiologically adapted to high concentrations of quaternary ammonium compounds
(Universidad Nacional, Costa Rica, 2023-08-28) Chacón, Luz; Rojas-Jimenez, Keilor; Arias-Andres, Maria
Benzalkoniumchloride(BAC)isaquaternaryammoniumcompound(QAC)widely used as the active ingredient of disinfectants. Its excessive discharge into wastewater is constant and in high concentrations, likely affecting the physiology of microbial communities. We compared the physiological community profile of activated sludge (AS) bacteria with and without prior in vitro exposure to a high concentration of BAC(10 mg L−1). We measured the community functional diversity, carbon substrate multifunctionality, and the median effective concentration thatinhibits carbon respiration (EC50) using Biolog EcoPlates supplemented with a gradient of 0–50 mg L−1 of BAC. Surprisingly, we did not find significant differences in the physiological parameters among treatments. Certain abundant bacteria, including Pseudomonas, could explain the community’s tolerance to high concentrations of BAC. We suggest that bacterial communities in wastewater treatment plants’ AS are “naturally” adapted to BAC due to frequent and high-dose exposure. We highlight the need to understand better the effects of QACs in wastewater, their impact on the selection of tolerant groups, and the alteration in community metabolic profiles.
Contributions of the academy for a better understanding of the oceans in Costa Rica
(Universidad Nacional, Costa Rica, 2024-03) Morales-Ramírez, Álvaro; Gómez-Ramírez, Eddy; Alfaro-Martínez, Eric; Hidalgo, Hugo G.; Ulate-Naranjo, Karol; Arias-Andres, Maria; Rojas-Villalobos, Fresia; Samper-Villarreal, Jimena; Wehrtmann, Ingo S.
El lanzamiento de la Década de los Océanos en el año 2017 estableció nuevas visiones entre la ciencia y política, para fortalecer la investigación y la gestión de los océanos y las costas. Con un 92% de superficie marina, Costa Rica es una nación de mar, que posee una gran diversidad marina, y que realiza esfuerzos para conocer mejor sus recursos costeros y marinos. En los últimos 20 años, se han desarrollado políticas para promover la gestión integrada de nuestras zonas costeras y la creación de áreas marinas protegidas. Mediante la investigación de las universidades públicas, conocemos mejor, aunque de manera incompleta, cómo se encuentran nuestros recursos pesqueros y acuicultura, los impactos de la contaminación marina y sus efectos sobre organismos y ecosistemas, los impactos del cambio climático, así como los esfuerzos para impulsar la conservación marina y la restauración de los ecosistemas marino-costeros y sus servicios. Del análisis de estas áreas de estudios, es evidente, que existen vacíos de información que deben ser abordados para generar más información científica que permita la toma de decisiones adecuadas y basadas en la ciencia, con el objeto de mejorar las políticas púbicas relacionadas a las zonas costeras, sus recursos, los servicios ecosistémicos, la gestión de las numerosas fuentes de contaminación continental que llegan a la costa y la adaptación al cambio climático.
Dissimilar behavioral and spatial avoidance responses by shrimps from tropical and temperate environments exposed to copper
(Universidad Nacional, Costa Rica, 2022-11-17) Redondo, Sergei; González, E.; Mena, F.; Araújo, Cristiano
Behavioral changes associated with exposure to pollutants represent the earliest response for organisms confronted by perceivable chemical signals. This study was carried out with the objective of evaluating behavioral responses associated with different scenarios of exposure to pollutants (non-forced vs forced) in two shrimp species (Penaeus vannamei and Palaemon varians), representative of different latitudes and using copper as a model contaminant. The effects on locomotion were evaluated by exposing the shrimps to a range of copper concentrations (0, 0.5, 5, 50, and 250 µg/L) in the forced scenario. After exposure, the movement patterns for each shrimp were recorded and used to estimate changes in the shrimps’ locomotion. For the non-forced scenario, the avoidance response was assessed by placing shrimps in a multi-compartment system where they were able to move freely along a gradient of copper (0, 0.5, 5, 50, and 250 µg/L). In terms of locomotion, an opposite trend was observed between the species: movements were significantly reduced in P. varians with concentrations above 50 µg/L, while hyperactivity was observed for P. vannamei. When exposed to a gradient of copper in the multi-compartment system, both species significantly avoided the highest concentrations of copper, although the repellence of copper was stronger for P. vannamei. In summary, both species of shrimps were able to recognize and avoid copper; however, in terms of locomotion, they showed an opposite behavioral reaction. These results show that a contamination event can have different behavioral outcomes depending on the species and complementing forced and non-forced exposure with species-specific information can be helpful to characterize and predict the effects of contaminants at higher biological levels.
Effects of the insecticide β-endosulfan on tadpoles of Isthmohyla pseudopuma (Anura: Hylidae)
(Universidad Nacional, Costa Rica, 2022) Méndez, M.; Mena, Freylan; Pinnock Branford, Margaret Verónica; Ruepert, Clemens
Conventional agriculture uses pesticides intensively. Once pesticides are released into the environment, they can be toxic to non-target organisms. Exposure of amphibians to pesticides can be lethal and affect their growth, development and behavior. β-endosulfan is a persistent organochlorine that has been detected in environmental samples within protected sites in Costa Rica, far from agricultural areas. The aim of this study was to evaluate the lethal and sublethal effects, as well as changes in three biomarkers (Cholinesterase activity [ChE], glutathione S- transferase activity [GST] and lipid peroxidation [LPO]) in tadpoles of Isthmohyla pseudopuma exposed to β-endosulfan. A 96-h acute test (20, 40, 60, 80, 100 and 200 µg/L) was performed in order to calculate the median lethal concentration (LC 50 ), while effects on growth and development were assessed during a 4-weeks chronic test (10, 20, 30 and 50 µg/L). In addition, we measured the aforementioned biomarkers in tadpoles exposed to concentrations below the LC 50 . The 96-h LC 50 for this species was 123.6 µg/L. We found no evidence of β-endosulfan influencing any of the three biomarkers evaluated. At 50 µg/L, both length and total weight of tadpoles decreased with respect to the control. Also, at 30 and 50 µg/L we observed that individuals showed a slower development. Therefore, we demonstrated that at sublethal concentrations, β-endosulfan negatively affects I. pseudopuma at early stages causing tadpoles to develop slower and smaller than normal.
El impacto de la resistencia a los antibióticos en el desarrollo sostenible
(Universidad de Costa Rica, 2022) Barrantes, K.; Chacon Jimenez, Luz; Arias Andrés, María
La resistencia a los antimicrobianos (RAM) es un problema de salud pública cada vez más complejo y se considera como una de las mayores amenazas en todo el mundo. El desarrollo de la RA en los patógenos bacterianos es una consecuencia esperada de la adaptación evolutiva, debido a la presencia de este tipo de contaminantes, los antibióticos, en variedad de nichos ecológicos. Además, hay múltiples factores asociados con su origen y diseminación, entre ellos, el uso desmedido y poco regulado de los antibióticos en la medicina humana y veterinaria, así como en la agricultura, la ganadería y la industria. De hecho, recientemente se ha indicado el papel del ambiente como reservorio para genes de RA y bacterias resistentes a antibióticos. En este sentido, el enfoque para contener y controlar este problema tan complejo involucra de forma necesaria a diversas áreas como la medicina, la veterinaria, las ciencias ambientales y sectores de la industria y la economía. En este artículo, se realiza una descripción tanto del problema de la RA y sus elementos causales, como del enfoque multidisciplinario que ha sido propuesto para su manejo en el ámbito global. Se detalla también cómo la RA afecta el desarrollo humano sostenible conforme a la Agenda 2030 formulada por la ONU, en el cumplimiento de algunos de los objetivos del desarrollo sostenible (ODS).
Identification of anthropogenic impact on natural habitats by antimicrobial resistance quantification in two neotropical wild cats and their geospatial analysis
(Universidad Nacional, Costa Rica, 2023) Angulo, A.; Fajardo, F.; Salom-Pérez, Roberto; Carazo Salazar, Javier; Taylor, Francisco; Pilé, Edwin; Quesada-Alvarado, Francisco; Blanco- Peña, Kinndle
Human activities such as habitat degradation and fragmentation threaten biodiversity in Neotropical areas. This work proposes an analytical methodology to identify natural areas in Central America with anthropogenic impact, analyzing the presence of antimicrobial resistance genes (ARGs) in accordance with their theoretical relationship with human-related activities. Sixteen ARGs were quantified in feces of different individuals of 13 jaguars (Panthera onca) and 13 pumas (Puma concolor) in three conservation areas in Costa Rica by real-time PCR. At least one ARG was detected in all samples. Of the ARGs encoding tetracycline resistance, the most frequent were tetQ and tetY (85% and 69%, respectively). The sulfonamides (sulI and sulII; 69% each), phenicols (catI and catII; 19% and 54%, respectively), and quinolones (qnrS; 12%) were also detected. The presence of human settlements, livestock farms (pigs, cattle, and poultry), roads, human health centers, flood zones, and rivers were identified within each area to generate an index of human activity. We found no difference between the presence of ARG by roads, agricultural activities, and human settlements (P.0.05). However, tetW showed higher percentages with porcine and bovine farms; both tetY and tetW were more frequent in jaguars than in pumas. Of concern is that many of the most contaminated samples were taken from national parks, such as Braulio Carrillo and Tortuguero, where animals should not have direct contact with humans.
TIER I Toxicity assessment Toxicity assessment of pesticides used in banana and pineapple plantations detected on the Río Madre de Dios watershed, Costa Rica
(Universidad Nacional, Costa Rica, 2014) Arias, M; Mena-Torres, F.; Ugalde, R.; Ramo, R.; Grandas, L.; Ruepert, Clemens

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