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Penicillin G and cloxacillin in Costa Rican dairy products: quantitative analysis and lactic acid bacteria resistance profiling
(2025-11-13) Solis Dobles, Maria Cristina; Quesada Solano, Melissa; Granados Chinchilla, Fabio; Cortés Herrera, Carolina; Redondo Solano, Mauricio; Fernandez Campos, Adriana
Milk and dairy products are among the most relevant foods both nutritionally and commercially. Costa Rica stands out as one of the main producers and consumers of dairy products in Central America. However, in recent years, the use of antibiotics in the livestock industry has increased, with implications for public health and food security, generating a need to monitor residues of these drugs in food. The present research focuses on developing a liquid chromatography method for the simultaneous quantification of penicillin G (PEN) and cloxacillin (CLO) in raw and commercial bovine milk, as well as in various dairy products, including fresh cheese and liquid yogurt. Methods/Results: During the validation of the methodology, average sensitivities of (960 ± 8)·101 mg L−1 and (1580 ± 9)·101 mg L−1 were achieved for PEN and CLO, respectively. Determination coefficients of 0.9995 and 0.9998 were also achieved, respectively. The limits of detection (LOD) and quantification (LOQ) for PEN and CLO were (0.330 ± 0.025) mg L−1 and (0.65 ± 0.12) mg L−1, (1.10 ± 0.083) mg L−1 and (2.2 ± 0.4) mg L−1, respectively, on both accounts. Recoveries were 68–77%, 92–106%, and 78–112% for PEN and 57–79%, 99–114%, and 95–120% for CLO in milk, cheese, and yogurt, respectively, across all three concentration levels evaluated. The precision of the method, in terms of reproducibility, was assessed for liquid yogurt (3–12% RSDR for PEN and 4–12% RSDR for CLO) and in cheese (8–14% RSDR for PEN and 4–12% RSDR for CLO). Nineteen bovine milk samples from the Cartago area were evaluated, including commercial and milk samples. Additionally, cheese (n = 17) and yogurt samples (n = 8) were analyzed. Conclusions: None of the samples showed detectable signals of the antibiotics. In addition, antibiotic sensitivity testing was performed on n = 9 Lactic Acid Bacteria (LAB) strains isolated from the raw milk samples, revealing the presence of some resistant traits to several antibiotics, including β-lactams.
Diversity and biology of deep-water crustaceans in Costa Rica
(2021-03-02) Azofeifa Solano, Juan Carlos; Cortés Núñez, Jorge
Crustaceans are an important component of deep-sea biodiversity. A brief review of the history of expeditions and studies related to deep-sea crustaceans in Costa Rica is presented. We briefly discuss studies on crustaceans from the Costa Rican deep-sea environments, and we provided an updated list of species recorded for the Pacific and the Caribbean. A total of 147 species has been reported from Costa Rican deep sea; 8 species have been reported from the Caribbean, 138 from the Pacific, and 1 from both basins. Decapoda was the most diverse group with 87 species, followed by Copepoda (23 spp.) and Peracarida (19 spp.). The first deep- sea exploration in Costa Rica began with foreign efforts, with national projects and participation increasing in recent years. Most research dealing with crustaceans has been focused on reproductive biology, in collaboration with the deepwater shrimp f isheries. Future efforts to study the Costa Rican deep-sea will incorporate collabo ration with foreign expeditions and private companies since the country does not have enough funding invested in its deep sea. Finally, we discuss the current threats to deep-sea crustaceans, as well as future perspectives for the study of this fascinat ing group in Costa Rica.
Habitat characteristics provide insights of carbon storage in seagrass meadows
(2018-02-17) Mazarrasa, Inés; Samper Villarreal, Jimena; Serrano, Oscar; Lavery, Paul S.; Lovelock, Catherine E.; Marbà, Núria; Duarte, Carlos M.; Cortés Núñez, Jorge
Seagrass meadows provide multiple ecosystem services, yet they are among the most threatened ecosystems on earth. Because of their role as carbon sinks, protection and restoration of seagrass meadows contribute to climate change mitigation. Blue Carbon strategies aim to enhance CO2 sequestration and avoid greenhouse gasses emissions through the management of coastal vegetated ecosystems, including seagrass meadows. The implementation of Blue Carbon strategies requires a good understanding of the habitat characteristics that influence Corg sequestration. Here, we review the existing knowledge on Blue Carbon research in seagrass meadows to identify the key habitat characteristics that influence Corg sequestration in seagrass meadows, those factors that threaten this function and those with unclear effects. We demonstrate that not all seagrass habitats have the same potential, identify research priorities and describe the implications of the results found for the implementation and development of efficient Blue Carbon strategies based on seagrass meadows.
Evaluación del rendimiento y la productividad del agua en soya (Glycine max) con Aquacrop
(2025-09-30) Zúñiga Herrera, Dania María; Chaves Barrantes, Néstor Felipe; Gutiérrez Soto, Marco Vinicio; Monge Muñoz, Mayela María; Chinchilla Soto, Isabel Cristina
Introducción. Los modelos de simulación son una herramienta para estudiar el comportamiento de los cultivos bajo distintas condiciones climáticas, hídricas y prácticas de manejo agronómico. Objetivo. Evaluar el modelo AquaCrop en la estimación del rendimiento y la productividad del agua en el cultivo de la soya variedad CIGRAS-06. Materiales y métodos. El estudio se realizó en la Estación Experimental Agrícola Fabio Baudrit Moreno de la Universidad de Costa Rica, en Alajuela, Costa Rica del 6 de junio al 23 de octubre del 2018. Se utilizó el modelo AquaCrop para simular el desarrollo y rendimiento del cultivo de soya. Se compararon datos simulados de cobertura del dosel vegetal, producción de biomasa y rendimiento, contra datos experimentales de una parcela sembrada con soya variedad CIGRAS-06. Se utilizaron parámetros de suelo medidos en campo y generados mediante ecuaciones de pedrotransferencia. Resultados Las predicciones del rendimiento, biomasa total y cobertura fueron buenas (similitud (d) ≥ 0,97), pero las predicciones de cobertura foliar durante el inicio del ciclo del cultivo son susceptibles de mejora. Las diferencias en los dos tipos parámetros de suelo utilizadas, no afectaron significativamente la simulación final. Conclusiones. AquaCrop permitió simular el rendimiento de la soya, la biomasa y la cobertura foliar satisfactoriamente. La simulación de la productividad del agua fue superior a otros valores reportados en la literatura.
A survey of Brevipalpus mite species and their predators in Costa Rican citrus and coffee plantations
(2026) Aguilar Piedra, Hugo; Solano Guevara, Ana María; Tassi, Aline Daniele; Ochoa, Ronald
Brevipalpus mites pose a significant threat to citrus and coffee production worldwide due to their transmission of plant viruses. This study surveyed all seven provinces of Costa Rica to identify Brevipalpus species associated with these economically vital crops. The investigation revealed the presence of five Brevipalpus species, including B. yothersi, a major vector of citrus leprosis cilevirus in numerous countries, B. papayensis, previously linked to coffee ringspot dichorhavirus in South America, B. phoenicis, B. californicus, and B. azores, vectors of dichorhaviruses causing citrus leprosis diseases. Despite their presence, no viral symptoms were observed in the plantations surveyed. Generalized linear models revealed different distributional patterns across altitude gradients; the probability of occurrence of B. papayensis increased with altitude, whereas the detection of B. yothersi declined at higher elevations across both hosts. The other three species occurred at very low frequencies; B. californicus and B. phoenicis were positively associated with altitude, though the latter only on Citrus. In contrast, B. azores slight decline with altitude on Citrus. In addition, the study documented 17 predatory mite species, 14 species belonging to Phytoseiidae and three to Stigmaeidae. This study examines the relationship between Brevipalpus distribution and altitude using empirical survey data across an entire country, demonstrating that Brevipalpus distributions in Costa Rica on these two hosts are strongly shaped by altitude and host, with species responding in contrasting ways. Such ecological differentiation has important implications for predicting virus risk under changing environmental conditions and provides a critical baseline for designing integrated pest management strategies in citrus and coffee production systems.