Artículos Científicos

URI permanente para esta colecciónhttp://10.0.96.45:4000/handle/11056/14635

Examinar

Mostrando 1 - 20 de 729

Detección molecular y análisis filogenético de Trypanosoma spp. (Kinetoplastida: Trypanosomatidae) en primates no humanos de Costa Rica.
(Sociedad Chilena de Parasitología, 2026-06) Solórzano-Morales, Anthony; Alfaro-Porras, Sergio; Tien Sung, Connie; Jiménez-Soto, Mauricio; Dolz, Gaby
Introducción: Los primates no humanos (PNH) neotropicales con frecuencia se infectan con una variedad de tripanosomas, incluido Trypanosoma cruzi, que causa la enfermedad de Chagas, una importante enfermedad zoonótica en América Latina. Objetivo: Determinar anticuerpos contra T. cruzi y caracterizar mediante métodos moleculares los tripanosomas presentes en PNH de Costa Rica. Métodos: Se analizaron 201 muestras de sangre recolectadas entre 2011-2016 de PNH salvajes (49) y en cautiverio (152) mediante hemaglutinación indirecta [IHA], inmunofluorescencia indirecta (IFA), reacción en cadena de la polimerasa (PCR) dirigida al ADNr 18S (SSU rDNA), secuenciación, análisis BLAST e inferencia filogenética por máxima verosimilitud. Resultados: Todos los sueros (123) analizados reaccionaron negativos en IHA, por lo tanto, no se realizó IFA. Un total de 21 (10%) de las muestras resultaron positivas en PCR, la secuenciación y el análisis (BLAST y filogenia) las determinó como Trypanosoma minasense. La presencia de este parásito se determinó en las cuatro especies de monos de Costa Rica (Cebus imitator [n=8], Alouatta palliata [n=5], Ateles geoffroyi [n=6], Saimiri oerstedii [n=2]); en cuatro provincias (Puntarenas [n=10], Alajuela [n=4], Limón [n=4] y Heredia [n=3]) y ambos estilos de vida (cautiverio [n=19], vida libre [n=2]). Conclusión: Este estudio constituye el primer informe molecular de T. minasense infectando PNH de Costa Rica. Se recomiendan realizar estudios sobre la biología de este parásito y la existencia de otras especies de tripanosomátidos, incluida T. cruzi, en PNH del país.
Testicular dimensions in boars
(Elsevier, 2018) Castillo-Badilla, Gloriana; Chacón, Jorge; Vargas Leitón, Bernardo
Testicular dimensions (Width and length) disclosed by age and breed are reported in AI boars from Costa Rica. Testicular volume is related with semen quality/fertility in most species. Although, selection of boar sires by this parameter is scarce in tropical areas. Furthermore, literature reports of testicular dimensions are rarely found in this specie.
Optimal age at first calving in pasture-based dairy systems
(MDPI, 2023-10-23) Vargas Leitón, Bernardo; Romero-Zúñiga, Juan José; Castillo-Badilla, Gloriana; Saborío Montero, Alejandro
The age at first calving (AFC) is one of the most used indicators to evaluate the efficiency of rearing systems in dairy cattle herds. The objective of the present study was to evaluate the association between AFC and different parameters of productive and reproductive efficiency in dairy cows of Holstein and Jersey breeds and their crosses. A retrospective longitudinal study was carried out with information on the performance of 77,311 cows with birth and culling dates between 1990 and 2016 from 633 specialized dairy herds from mid and high-altitude regions of Costa Rica. Cows were classified into five categories according to their age in months at first calving (≤ 24, 25–27, 28–30, 31–33, ≥ 34). A generalized linear mixed model was used to assess the effect of AFC and racial factors on milk production (first lactation, lifetime total, and per day of life), open period (first calving and lifetime total), and herd life. The mean AFC was 29.5, 29.1, and 28.0 months for Holstein, Holstein×Jersey, and Jersey, respectively. The AFC was significantly associated (P < 0.01) with all the variables evaluated. Cows with AFC ≤ 24 presented a higher (P < 0.01) milk production (total lifetime and per day of life), as well as a longer herd life, compared to cows in categories of AFC > 28 m. The reduction in AFC contributes to a significant increase in the efficiency of dairy herds in Costa Rica.
Encuesta a productores ovinos y caprinos de Costa Rica: perspectivas, riesgos y desafíos sanitarios del sector
(Universidad Nacional, Costa Rica, 2024-12-27) Soto-Barrientos, Natalia; Vargas Leitón, Bernardo
En Costa Rica la producción caprina y ovina ha venido creciendo progresivamente durante los últimos años, sin embargo, la información que existe sobre estos sistemas de producción es aún escasa e imprecisa. Por tal motivo se realizó una encuesta en una muestra de 100 explotaciones (64 caprinas y 36 ovinas) con el propósito de realizar un diagnóstico base de los sistemas de producción ovinos y caprinos en Costa Rica, principalmente en aspectos relacionados con el manejo nutricional, reproductivo y sanitario. La casi totalidad de los hatos caprinos se dedican a la producción de leche, con un promedio de 17 hembras adultas por hato, mientras que los hatos ovinos se dedican todos a la producción de carne, con una media de 55 hembras. Se observó un uso frecuente de sistemas estabulados (52%) o semiestabulados (51%), y una menor frecuencia de pastoreo extensivo (28%). La media de edad de los productores encuestados fue de 45 años, con una experiencia media en la actividad de 8.8 años en la actividad. El 69% de los productores tienen al menos un nivel educativo superior a la secundaria. La mayoría de las fincas (88%) mantiene algún tipo de registro, manual o digital. El 91% de los hatos utiliza la monta natural con machos propios de la finca. La encuesta evidenció importantes deficiencias en materia de bioseguridad y manejo sanitario. Se detectó además presencia de riesgos sanitarios potenciales. Los problemas de salud reportados con mayor frecuencia en los hatos fueron abortos y problemas al parto, así como problemas respiratorios, diarreas y renqueras. Se evidenció una asociación positiva significativa entre la presencia de riesgos de bioseguridad y la prevalencia de problemas de salud. Estos hallazgos ofrecen una perspectiva esencial para orientar futuras políticas y acciones destinadas a promover el desarrollo y la sostenibilidad de la industria ganadera en el país.
The spatiotemporal ecology of Oropouche virus across Latin America: a multidisciplinary, laboratory-based, modelling study
(Elsevier, 2025-04-14) Fischer, Carlo; Frühauf, Anna; Inchauste, Lucia; Anzolini Cassiano, Murilo Henrique; Arévalo Ramirez, Heriberto; Barthélémy, Karine; Bautista Machicado, Lissete; Bozza, Fernando Augusto; Brites, Carlos; Cabada, Miguel Mauricio; Cabezas Sánchez, César; Cervantes Rodríguez, Angie; de Lamballerie, Xavier; Peralta Delgado, Roxana de los Milagros; de Oliveira-Filho, Edmilson; Domenech de Cellès, Mathieu; Franco-Muñoz, Carlos; García Mendoza, María Paquita; Gatty Nogueir, Miladi; Gélvez-Ramírez, Rosa-Margarita; Gonzalez Gonzalez, Manuel; Gotuzzo, Eduardo; Kramer-Schadt, Stephanie; Kuivanen, Suvi; Laiton-Donato, Katherine; Lozano-Parra, Anyela; Málaga Trillo, Edward; Valencia Manos Alva, Dora; Missé, Dorothée; Moreira-Soto, Andres; Moreno Souza, Thiago; Mozo, Karen; Martins Netto, Eduardo; Olk, Nadine; Pachamora Diaz, Johanna Maribel; Pedroso Jorge, Célia; Pérez Astudillo, Ana Micsuco; Piche-Ovares, Marta; Priet, Stephane; Rincón-Orozco, Bladimiro; Romero-Zúñiga, Juan José; Salgado Cisneros, Silvia Paola; Stöcker, Andreas; Villalobos Ugalde, Juan Carlos; Villar Centeno, Luis Angel; Wenzler-Meya, Moritz; Zevallos, Juan Carlos; Drexler, Jan Felix
Background: Latin America has been experiencing an Oropouche virus (OROV) outbreak of unprecedented magnitude and spread since 2023–24 for unknown reasons. We aimed to identify risk predictors of and areas at risk for OROV transmission. Methods: In this multidisciplinary, laboratory-based, modelling study, we retrospectively tested anonymised serum samples collected between 2001 and 2022 for studies on virus epidemiology and medical diagnostics in Bolivia, Brazil, Colombia, Costa Rica, Ecuador, and Peru with nucleoprotein-based commercial ELISAs for OROV-specific IgG and IgM antibodies. Serum samples positive for IgG from different ecological regions and sampling years were tested against Guaroa virus and two OROV glycoprotein reassortants (Iquitos virus and Madre de Dios virus) via plaque reduction neutralisation testing (PRNT) to validate IgG ELISA specificity and support antigenic cartography. Three OROV strains were included in the neutralisation testing, a Cuban OROV isolate from the 2023–24 outbreak, a contemporary Peruvian OROV isolate taken from a patient in 2020, and a historical OROV isolate from Brazil. We analysed the serological data alongside age, sex, cohort, and geographical residence data for the serum samples; reported OROV incidence data; and vector occurrence data to explore OROV transmission in ecologically different regions of Latin America. We used the MaxEnt machine learning methodology to spatially analyse and predict OROV infection risk across Latin America, fitting one model with presence–absence serological data (seropositive results were recorded as presence and seronegative results were recorded as absence) and one model with presence-only, reported incidence data from 2024. We computed marginal dependency plots, variable contribution, and permutation metrics to analyse the impact of socioecological predictors and fitted a generalised linear mixed-effects model with logit link and binary error structure to analyse the potential effects of age, sex, or cohort type bias and interactions between age or sex and cohort type in our serological data. We conducted antigenic cartography and evolutionary characterisations of all available genomic sequences for all three OROV genome segments from the National Center for Biotechnology Information, including branch-specific selection pressure analysis and the construction of OROV phylogenetic trees. Findings: In total, 9420 serum samples were included in this study, representing 76 provinces in the six Latin American countries previously mentioned. The sex distribution across the combined cohorts was 48% female (4237 of 8910 samples with available data) and 52% male (4673 of 8910 samples) and the mean age was 29·5 years (range 0–95 years). The samples were collected from census-based cohorts, cohorts of healthy individuals, and cohorts of febrile patients receiving routine health care. The average OROV IgG antibody detection rate was 6·3% (95% CI 5·8–6·8), with substantial regional heterogeneity. The presence–absence, serology-based model predicted high-risk areas for OROV transmission in the Amazon River basin, around the coastal and southern areas of Brazil, and in parts of central America and the Caribbean islands, consistent with case data from the 2023–24 outbreak reported by the Pan American Health Organization. Areas with a high predicted risk of OROV transmission with the serology-based model showed a statistically significant positive correlation with state-level incidence rates per 100 000 people in 2024 (generalised linear model, p=0·0003). The area under the curve estimates were 0·79 (95% CI 0·78–0·80) for the serology-based model and 0·66 (95% CI 0·65–0·66) for the presence-only incidence-based model. Longitudinal diagnostic testing of serum samples from cohorts of febrile patients suggested constant circulation of OROV in endemic regions at varying intensity. Climate variables accounted for more than 60% of variable contribution in both the serology-based and incidence-based models. Antigenic cartography, evolutionary analyses, and in-vitro growth comparisons showed clear differentiation between OROV and its glycoprotein reassortants, but not between the three different OROV strains. PRNT titres of OROV-neutralising serum samples were strongly correlated between all three tested OROV isolates (r>0·83; p<0·0001) but were not correlated with the two glycoprotein reassortants. Interpretation: Our data suggest that climatic factors are major drivers of OROV spread and were potentially exacerbated during 2024 by extreme weather events. OROV glycoprotein reassortants, but not individual OROV strains, probably have distinct antigenicity. Preparedness for OROV outbreaks requires enhanced diagnostics, surveillance, and vector control in current and future endemic areas, which could all be informed by the risk predictions presented in this Article.
Índice Compuesto de Riesgo por covid-19 desde una perspectiva geográfica: Costa Rica, marzo 2020 a mayo 2022
(Universidad de Costa Rica, 2026-04-20) Chamizo García, Alejandro Horacio; Romero-Zúñiga, Juan José
Se diseñó un estudio epidemiológico, ecológico, con fundamento territorial para analizar el riesgo de enfermar y de morir por covid-19, de manera combinada, utilizando el Índice Compuesto de Riesgo, desde la perspectiva geoespacial y con enfoque de los Determinantes Sociales de la Salud. Se identificaron conglomerados calientes del Índice Compuesto de Riesgo (alto riesgo) ubicados en la Gran Área Metropolitana, y fríos (bajo riesgo) flanqueando o limitándolo. El incremento del promedio de vacunas por habitantes en una unidad se asoció con un 2% menos en el ICR. El aumento del porcentaje de viviendas hacinadas, de personas no aseguradas, de personas nacidas en el exterior, así como de la densidad poblacional y el Índice de Desarrollo Social, incrementaron en 1% o 2% el ICR. El ICR aporta conocimiento sobre la gravedad de la epidemia por covid-19, su comportamiento en el espacio geográfico es claramente diferenciado, así como la capacidad explicativa de los DSS. La vecindad geográfica jugó un papel muy importante en la epidemia de covid-19 en Costa Rica.
Uncovering biosecurity gaps: risk factors for PRRSV seropositivity in Costa Rican pig farms identified through machine learning
(Springer Nature, 2026-02-21) Meléndez-Arce, Ronald; Jiménez-Loaiza, Emily; Leiva-Bonilla, Berta; Venegas-Soto, Juan Carlos; Rocha-Palma, Milania; Van Nes, Arie; Stegeman, Arjan; Vernooij, Hans; ROMERO-ZUÑIGA, JUAN JOSÉ
Background Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) continues to impose significant economic losses on pig production globally. In Costa Rica, where the virus is endemic, there is limited knowledge of the farm-level risk factors influencing PRRSV spread. This study aimed to identify biosecurity factors associated with PRRSV seroprevalence in Costa Rican pig farms. Methods A cross-sectional survey was conducted on 21 pig farms across Costa Rica. Data on farm management and biosecurity practices were collected using a structured questionnaire and linked to PRRSV seroprevalence data from a companion study. Logistic regression, and machine learning methods like LASSO (Least Absolute Shrinkage and Selection Operator), and Random Forest models were used to identify significant risk factors associated with herd level PRRSV positivity. Results Three key risk factors were consistently identified by both LASSO and Random Forest models: historical controlled exposure to PRRSV, restrictions on employee access to the farm, and restrictions on employee visits to other pig farms. Additional risk factors identified included topography, disinfection practices for transport vehicles, sanitation measures for visitors, boot and clothing protocols, and feedback procedures. Farms with a history of controlled exposure had an odds ratio of 90 (95% CI: 7.6–3,550) for being PRRSV-positive. Conclusion The findings underscore the importance of internal and external biosecurity measures, particularly in relation to personnel movement and intentional exposure practices. Modeling approaches such as LASSO and Random Forest provided complementary insights into PRRSV risk factors in a tropical production setting. These insights can guide tailored interventions to reduce PRRSV transmission in Costa Rica and similar regions.
Adherence to the EAT-Lancet Diet is Not Associated With Weight Status in a Latin American Urban Multicentric Study
(John Wiley & Sons Ltd, 2025-04-25) Vargas-Quesada, Rulamán; Monge-Rojas, Rafael; ROMERO-ZUÑIGA, JUAN JOSÉ; Araya-Bastias, Carolina; Kovalskys, Irina; Herrera-Cuenca, Marianella; Cortés, Lilia Yadira; Yépez García, Martha; Liria-Domínguez, Reyna; Rigotti, Attilio; Fisberg, Mauro; Gómez, Georgina
The overweight/obesity high prevalence and the effects of climate change in Latin America underscores the possible positive outcomes of adopting a healthy and sustainable diet to respond to the region’s burden of nutrition-related noncommunicable diseases (NCDs). However, research on adherence to the EAT-Lancet diet in Latin America and its association with overweight/obesity is limited. This study explores the relationship between the EAT-Lancet diet adherence and overweight/obesity in a cross-sectional and urban multicentric study involving 6683 participants aged 15–65. Adherence to the EAT-Lancet diet was evaluated using the Planetary Health Diet Index (PHDI). The findings indicate that high adherence to the EAT-Lancet diet (fifth quintile) was not significantly associated with overweight/obesity (reference: first PHDI quintile, PR: 1.057, CI: 0.993–1.125, p-trend = 0.140) after adjusting for key covariates. Equivalent outcomes were found when assessing adherence to the EAT-Lancet diet using the EAT-Lancet Index, the World Index for Sustainability and Health (WISH), and the Healthy and Sustainable Diet Index (HSDI), after adjusting for the same variables. The persistently high prevalence of overweight/obesity among different adherence levels to the dietary pattern and the study’s design, do not appear to be the key factors contributing to the lack of association between these variables. Instead, the considerably low adherence to the EAT-Lancet diet in the sample as well as the low variability in adherence across participants with and without excess weight might help explain the lack of observed association. However, further research is needed to verify this conclusion.
Productive and reproductive losses associated with abortion in specialized dairy cattle from Costa Rica
(Elsevier, 2025-05) Vindas-van der Wielen, Emilia; ROMERO-ZUÑIGA, JUAN JOSÉ; Monti, Gustavo
Abortions can negatively affect a dairy farm's milk yield, reproductive efficiency, and profitability. Despite the recognized economic losses associated with abortions, the reproductive and productive detriments caused by abortion have not been estimated in dairy cattle in tropical productive conditions such as those in Costa Rica. Therefore, this study aimed to evaluate the potential productive and reproductive losses caused by abortions in dairy cattle from Costa Rica. The reproductive and productive losses caused by abortion were estimated using a dataset with 953,181 complete lactations from 322,873 cows belonging to 1,133 Costa Rican specialized dairy herds. Abortions were classified as early fetal mortality (EFM) and late fetal mortality (LFM). The number of services per conception (NSPC) and calving to effective conception interval (CECI) indicated the reproductive losses. The productive losses were indicated by the DIM per lactation and per cow, productive lifetime, 305-d milk yield per lactation (305-d MY), total milk yield per lactation (TMYPL), and total lifetime milk yield per cow (LTMY). Generalized linear mixed models were adjusted by cow breed, parity, and ecozone, using farm and cow as random effects. Cows that experienced an EFM during the lactation had NSPC increase by 1.61, CECI by 8 d, DIM per lactation by 11 d, 305-d kg by 283 kg, and TMYPL by 297 kg. Cows that experienced a LFM during the lactation had an increase of 0.22 NSPC and a reduction of 33 DIM per lactation, 201 d of productive lifetime, 1,006 kg of 305-d MY, and 1,518 kg of TMYPL. Furthermore, as the parity with abortions increased from 0 to 3 or more, the DIM per cow increased. Still, we found no significant difference in the LTMY when the number of lactations with abortions increased. These results illustrate the impact of abortions on the reproductive and productive performance of cows and, consequently, on the profitability of dairy herds from a tropical country like Costa Rica.
Impacto ambiental de la cadena de producción de pollo de engorde bajo sistemas convencionales
(Universidad de Costa Rica, 2025) Portillo Chávez, Felipe; Vargas Leitón, Bernardo
Introducción. La producción de pollo de engorde es una actividad de creciente importancia económica a nivel mundial, pero que conlleva un impacto ambiental significativo. Objetivo. Estimar el impacto ambiental de la cadena de producción de pollo de engorde bajo sistemas convencionales. Materiales y métodos. Se utilizó la metodología de análisis de ciclo de vida (ACV) “de la cuna a la puerta”. Los parámetros de base se obtuvieron de una granja avícola ubicada en el cantón de San Ramón, Alajuela, Costa Rica, entre enero y diciembre de 2021. La unidad funcional del ACV fue una tonelada métrica de carne de pollo (tM CP) y se consideraron las categorías de impacto ambiental incluidas en el sistema ReCiPe 2016 v.1.1, con factores de caracterización en nivel de punto medio, bajo una perspectiva jerarquista. Resultados. Los impactos ambientales estimados, en unidades equivalentes por tM CP, fueron los siguientes: calentamiento global, 5208 kg CO2; acidificación terrestre, 52,6 kg SO2; eutrofización marina, 4,19 kg N; eutrofización de agua dulce, 2,47 kg P; uso de la tierra, 5238 m2 año cultivo; consumo de agua, 3962 m3; ecotoxicidad terrestre, 1831 kg 1,4-DCB; ecotoxicidad marina, 2,79 kg 1,4-DCB; ecotoxicidad de agua dulce, 8,49 kg 1,4-DCB; toxicidad humana (cancerígena), 1,13 kg 1,4-DCB; toxicidad humana (no cancerígena), 84,4 kg 1,4 DCB; formación de partículas finas, 8,15 kg PM2.5; agotamiento de recurso fósil, 246,1 kg petróleo; formación de ozono (salud ecosistémica), 10,8 kg NOx; formación de ozono (salud humana), 10,7 kg NOx, y agotamiento de ozono estratosférico, 0,043 kg CFC11. Conclusiones. Los procesos con mayor contribución a los impactos ambientales evaluados en este estudio fueron la producción de alimentos, fertilizantes y combustibles, así como el manejo de los residuos de la granja. La mayor parte del impacto ambiental atribuible a la cadena de producción del pollo de engorde sucede fuera de Costa Rica.
A case report of fungal pneumonia in an orphaned northern tamandua (Tamandua mexicana)
(International Wildlife Rehabilitation Council, 2026) García-Dobles, Santiago; Calderón-Hernández, Alejandra; Carvajal-Matamoros, Vinicio; Olivares, Roberto
Respiratory infections in captive juvenile wild animals are common; however, information on tamanduas is limited. The aim of this paper is to report a case of fungal pneumonia in a juvenile northern taman-dua. An orphaned, hand-raised female juvenile northern tamandua (Tamandua mexicana) exhibited nasal secretions and stertorous breathing a month after her capture. Following her death, a necropsy, lung cultures, and histology were per-formed. Gross and microscopic lesions were consistent with bilateral interstitial pneumonia and purulent, histiocytic bronchopneumonia containing intralesional yeasts. Rhodotorula glutinis and Nakaseomyces glabratus (formerly Candida glabrata) were confirmed by fungal culture and identified by biochemical testing and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS). To our knowledge, this is the first report of a mixed-pattern fungal pneumonia in a northern tamandua, underscoring the importance of considering fungal infections in wildlife species, particularly when dinical findings mimic other disease processes. Wildlife clinicians should include these pathogens in their differential diagnoses to enable timely diagnosis and appropriate therapeutic intervention.
Efectos genéticos y ambientales sobre la producción de cabras lecheras bajo condiciones tropicales semi-intensivas
(Universidad de Costa Rica, 2025-02-04) Campos Alfaro, Jorge Andrés; Vargas Leitón, Bernardo; Alpízar-Naranjo, Andrés; Padilla-Fallas, José; Camacho-Cascante, Isabel
Introducción. El estudio de los factores que afectan el rendimiento productivo de las cabras lecheras bajo condiciones tropicales es esencial para lograr un óptimo aprovechamiento de los recursos disponibles. Objetivo. Cuantificar el impacto de factores genéticos y ambientales que afectan el rendimiento productivo de cabras lecheras bajo condiciones tropicales semi-intensivas. Materiales y métodos. La investigación se llevó a cabo en la Finca Experimental Santa Lucía de la Universidad Nacional, Heredia, Costa Rica. El periodo experimental se extendió desde enero 2007 hasta diciembre de 2023. Se analizaron 15 686 registros diarios de pesaje de leche, en 191 cabras lecheras de tipos raciales Saanen (S) y Saanen×Toggenburg (S×T). Se utilizó un modelo lineal mixto generalizado para evaluar el efecto de las distintas variables predictoras sobre la producción diaria de leche, y se ajustaron curvas de lactancia estándares para distintas condiciones genético-ambientales mediante la función Wood. Resultados. Se determinaron efectos altamente significativos (p < 0,001) de las variables número de parto, año de parto, semana de lactancia, categoría de padre, número de crías, época y mes de parto sobre la producción de leche. Para cabras primerizas de razas S y S×T paridas en la época lluviosa se estimaron picos de producción diaria de 2,46 y 2,54 kg, alcanzados en las semanas 6,4 y 5,9, y persistencias al finalizar las lactancias de 86 y 84 %, respectivamente. Conclusiones. Ser cabras multíparas y disponer de alimentos con un mayor contenido nutricional durante la época lluviosa fueron factores asociados a una mayor producción de leche. Las curvas de lactancia evidenciaron patrones distintos en la producción de leche entre cabras primerizas y multíparas, así como entre las distintas épocas de parto y tipos raciales. El estudio proporciona información valiosa para validar a nivel comercial y optimizar el manejo de cabras lactantes en condiciones tropicales semi-intensivas.
A socioenvironmental approach to the nosogenic potential of freshwaters with presence of thermotolerant free-living amoebae in Costa Rica
(Frontiers in Public Health, 2025-10-06) Alvarado-Ocampo, Johan; ROMERO-ZUÑIGA, JUAN JOSÉ; Castro, Julián; Chaves Monge, Frida; Ruiz Campos, Marco; Bustamante Cortés, Alexa; Abrahams Sandí, Elizabeth; Retana Moreira, Lissette
Introduction: Within the group of free-living amoebae (FLA), the genus Naegleria stands out for including species adapted to high temperatures, such as the facultative human parasite Naegleria fowleri, that can be found in various terrestrial and aquatic environments. Characterizing and monitoring water bodies is crucial for determining the presence of pathogenic microorganisms and assessing the risk of infection. In this study, we propose an environmental survey to identify physicochemical parameters related to the presence of Naegleria in natural freshwater sources used for recreation in Costa Rica, as well as people’s knowledge, attitudes, and practices (KAP) profile in relation to the infection by N. fowleri.Materials and methods: Water and sediment samples were collected from 24 locations. Parameters such as temperature, pH, electrical conductivity, and dissolved oxygen in water were measured. In sediment, analyses were performed for metals, cations, and texture. Water samples were also filtered, cultured, and subjected to molecular analyses to determine the presence of FLA. Additionally, a KAP survey was conducted among 72 individuals during the fieldwork. Results: FLA were isolated at 42 °C from 22 sites, 7 of which tested positive for Naegleria. Although some parameters were statistically associated (p < 0.05) with the presence of Naegleria, epidemiological association was not demonstrated. From the KAP survey, 37.5% of participants had never heard about N. fowleri. Average scores of 35.8% for knowledge, and 3.01 and 2.16 for attitudes and practices were obtained, with 5 being the optimum value. Significant differences (p < 0.05) between the level of knowledge by gender and geographic origin were obtained.Conclusion: This study represents a first monitoring effort to determine the frequency of FLA in surface waters of Costa Rica, indicating the presence of thermotolerant vahlkampfiid FLA in non-thermal freshwaters with the ability to proliferate at high temperatures. The KAP survey revealed a low level of knowledge and deficiencies in the management and prevention of PAM risk among the population exposed to natural freshwater reservoirs. These findings must drive health promotion, communication, and education strategies in the local population exposed to risky recreational activities.
Unveiling the genetic structure of Costa Rican bovines through genetic admixture models
(Universidad de Costa Rica, 2025) Vargas Leitón, Bernardo; Núñez-Cárdenas, Johnny; Valverde, Anthony; León-Rodríguez, Bernal
Introduction. The cattle population in Costa Rica is highly diverse due to the variety of production systems, ongoing crossbreeding, and the increase in genetic imports. Under these circumstances, admixture models provide a more suitable approach to describe the genetic composition of this population than phylogenetic trees based on predefined populations. Objective. To model the genetic structure of the Costa Rican cattle population by means of supervised and unsupervised genetic admixture models. Materials and methods. Hair samples from 1412 randomly selected bovines from 744 herds across 8 regions of Costa Rica were collected in 2015 and genotyped for 18 microsatellite markers. Two approaches that make use of admixture genetic models were compared: an unsupervised scenario, based exclusively on genotype data; and a supervised scenario, which relied on genetic data assisted by prior information on phenotype and production purpose. Results. Analysis of genetic data under both scenarios provided similar results when the number of clusters (K) was lower than five, although estimates from the supervised model were more homogeneous with lower standard deviations. A priori defined subpopulations were distributed consistently among clusters in both scenarios. The most probable subpopulation clustering was observed at K = 3, which mainly separated Bos indicus breeds, Jersey and other Bos taurus breeds. Breed types clustered concordantly with breed clustering, shedding light on the genetic structure of the population. Conclusions. The combination of admixture genetic models under a supervised approach yielded the most consistent results, which reveals the importance of considering genetic-environmental interrelationships to achieve a more precise description of the genetic structure of the Costa Rican cattle population.
Parámetros genéticos de crecimiento en un hato caprino lechero bajo manejo semi-intensivo en ambiente tropical
(Universidad de Costa Rica, 2026-03-24) Campos Alfaro, Jorge Andrés; Vargas Leitón, Bernardo; Alpízar-Naranjo, Andrés
Introducción. La estimación de parámetros genéticos de crecimiento en caprinos permite identificar la contribución de efectos aditivos directos y maternos en distintas etapas del desarrollo, fundamental para diseñar estrategias de selección más eficientes. Objetivo. Estimar parámetros genéticos de crecimiento mediante modelos de regresión aleatoria en un hato caprino lechero. Materiales y métodos. El estudio se realizó en el hato experimental de la Universidad Nacional, Heredia, Costa Rica. Se analizaron 6127 registros de peso corporal desde el nacimiento hasta los 30 meses de edad de 388 hembras y 108 machos caprinos de razas Saanen y Saanen×Toggenburg, recolectados entre los años 2008 y 2024. Se ajustó un modelo mixto de regresión aleatoria, con efectos fijos de grupo contemporáneo, tipo racial, sexo, paridad, tipo de parto y edad; efectos aleatorios: genético aditivo directo (h2d), materno (h2m), y no genético de ambiente permanente directo (ap), ajustados mediante polinomios Legendre. Resultados. El valor de h2d osciló entre 0,01 (mes 2, EE 0,01) y 0,17 (mes 11, EE 0,08), la h2m varió entre 0,02 (mes2, EE 0,01) y 0,25 (mes 1, EE 0,07), y el valor de ap se incrementó progresivamente desde 0,03 (mes 1, EE 0,20) hasta 0,67 (mes 30, EE 0,08). Las correlaciones genéticas (directas o maternas) y de ambiente permanente fueron en su mayoría positivas y de magnitud moderada (>0,60), con valores más altos (>0,80) para pesos en edades adyacentes. Los valores de cría (directos) para peso corporal oscilaron entre −2,33 y 1,80 kg (mes 6) y entre −3,90 y 3,20 kg (mes 12). Conclusiones. El uso de modelos de regresión aleatoria permitió estimar parámetros genéticos de crecimiento considerando la influencia del animal y el efecto materno en distintas etapas, lo que facilita seleccionar reemplazos con mayor precisión y orientar las estrategias de mejora para obtener animales más productivos y eficientes.
Caracterización molecular de Taenia saginata en bovinos sacrificados en mataderos de Costa Rica
(Universidad Nacional, Costa Rica, 2026-01-01) Alcántara Henríquez, Elisa María; Dolz, Gaby
La cisticercosis bovina (CCB) es una enfermedad zoonótica parasitaria de importancia veterinaria y sanitaria que afecta la producción de ganado bovino en Costa Rica. El agente causal es la forma larvaria de Taenia saginata, quien necesita a los bovinos para cumplir su ciclo de vida. Este estudio tiene como objetivo determinar la distribución de casos de CCB en mataderos de exportación del país y caracterizar molecularmente T. saginata en muestras sospechosas. Se realizó un estudio transversal, analizando los reportes de retenciones y decomisos de CCB registrados por el Servicio Nacional de Salud Animal (SENASA) entre 2015 y 2019 en cuatro mataderos de exportación del país. A partir de estos datos, se identificó la cantidad y distribución de los casos en los cantones de Costa Rica. Adicionalmente, se recolectaron quistes sospechosos de CCB para realizar una detección mediante la técnica de reacción en cadena de la polimerasa (PCR). Los resultados mostraron que fueron reportados un total de 852 casos, siendo la mayoría de ellos provenientes de Alajuela (33.5%), San José (21.1%) y Guanacaste (10.8%). Los cantones de Alajuela (n=118) y San Carlos (n=90) en la provincia de Alajuela presentaron las cifras más altas de casos. Se recolectaron 24 quistes durante junio-agosto del 2020. La mayoría provenía de la provincia de Alajuela con el 58.3% hallados en músculos maseteros. El análisis por PCR detectó T. saginata en 11 muestras (45.8%), y la secuenciación reveló dos genotipos distintos, con similitudes nucleotídicas del 100% con aislamientos de Corea del Sur, Brasil, Ecuador y Bélgica, así como un genotipo que mostró similitud con un aislamiento de China. Estos hallazgos destacan la prevalencia y distribución de la cisticercosis bovina en Costa Rica, así como la importancia de implementar medidas de control y prevención efectivas.
Brucella abortus impairs T lymphocyte responsiveness by mobilizing IL-1RAsecreting omental neutrophils
(Nature Communications, 2025-02-20) Pellegrini, Joaquin; González-Espinoza, Gabriela; Shayan, Raheleh; HYSENAJ, LISIENA; Rouma, Tomas; Arce-Gorvel, Vilma; Lelouard, Hugues; Popoff, Dimitri; Zhao, Yun; Hanniffy, Sean; Castillo-Zeledón, Amanda; Loperena-Barber, Maite; Celis-Gutierrez, Javier; Mionnet, Cyrille; Bosilkovsk, Mile; Solera, Javier; Muraille, Eric; BARQUERO-CALVO, ELIAS; Moreno, Edgardo; Conde-Álvarez, Raquel; Moriyón, Ignacio; Gorvel, Jean Pierre; Mémet, Sylvie
Immune evasion strategies of Brucella, the etiologic agent of brucellosis, a global zoonosis, remain partially understood. The omentum, a tertiary lymphoid organ part of visceral adipose tissue, has never been explored as a Brucella reservoir. We report that B. abortus infects and replicates within murine omental macrophages. Throughout the chronic phase of infection, the omentum accumulates macrophages, monocytes and neutrophils. The maintenance of PD-L1+Sca-1+ macrophages, monocytes and neutrophils in the omentum depends on the wadC-encoded determinant of Brucella LPS. We demonstrate that PD-L1+Sca-1+ murine omental neutrophils produce high levels of IL-1RA leading to T cell hyporesponsiveness. These findings corroborate brucellosis patient analysis of whole blood displaying upregulation of PDL1 and Ly6E genes, and of serum exhibiting high levels of IL-1RA. Overall, the omentum, a reservoir for B. abortus, promotes bacterial persistence and causes CD4+ and CD8+ T cell immunosuppression by IL-1RA secreted by PD-L1+Sca-1+ neutrophils.
Polymorphonuclear neutrophil depletion in ileal tissues reduces the immunopathology induced by Clostridioides difficile toxins
(Elsevier, 2025-02-27) Montoya-Torres, Brayan; Alfaro-Alarcón, Alejandro; Quesada-Gómez, Carlos; Chaves-Olarte, Esteban; BARQUERO-CALVO, ELIAS
Introduction: Clostridioides difficile, a leading cause of healthcare-associated infections, causes significant morbidity and mortality. Its pathogenesis centers on TcdA and TcdB toxins, which disrupt intestinal integrity, trigger inflammation, and promote extensive neutrophil infiltration.Objective: The main objective of this study was to evaluate the role of PMNs in CDI using neutrophil depletion in a murine-ileal-ligated loop. Methods: Mice were treated with C. difficile toxins TcdA, TcdB, and TcdBv, with PMN depletion achieved via intraperitoneal injections of Ly6G/Ly6C antibody. Histopathological analysis, cytokine quantification, and MPO activity assays were performed to assess the inflammatory and tissue damage responses. Results: PMN depletion significantly reduced histopathological damage and proinflammatory responses. TcdA induced the highest inflammation and epithelial damage, while TcdB showed lower activity, except for MPO. TcdBvNAP1's activity was comparable to that of TcdBNAP1 but less than TcdA. The findings indicate that TcdA's enterotoxin effects are more damaging than TcdBs from different strains and confirm the critical role of PMNs in CDI pathogenesis. Conclusion: Our results show that PMN depletion reduced inflammatory responses and tissue damage, highlighting potential therapeutic strategies targeting PMN regulation. Further research on PMN extracellular traps (NETs) and their role in CDI is necessary to develop comprehensive treatments. Future studies should focus on combined in vivo and in vitro approaches to fully understand the pathological mechanisms and identify effective biomarkers for CDI therapy.
Mortality Investigation of a Free-ranging Baird's Tapir (Tapirus bairdii) in a Fragmented Landscape in Northern Costa Rica
(Wildlife Disease Association, 2025-10-04) Rojas-Jiménez, Jorge; Hernández, Sonia; Rojas-Valerio, Emmanuel; Olivares, Roberto; BARQUERO-CALVO, ELIAS
In Costa Rica, human–tapir conflicts are increasing, including disease transmission, as Baird’s tapirs (Tapirus bairdii) move into human-altered landscapes. We investigated the death of a wild male tapir, identifying a systemic Actinomyces israelii infection. The potential of this pathogen being an emerging health threat for tapir conservation warrants further study.
Clostridioides difficile RT596: una cepa no-toxigénica multidrogoresistente
(Central American Journals Online, 2025-06-19) Adino-Molina, Mauricio; BARQUERO-CALVO, ELIAS; Seyboldt, Christian; Schmoock, Gernot; Neubauer, Heinrich; Tzoc, Edgardo; Rodríguez, César; Quesada-Gómez, Carlos
Clostridioides difficile es un agente patógeno del tipo “Una sola salud”, y que es responsable de la diarrea asociada a antibióticos. Su epidemiología es dinámica, y se ha reportado que existe un cruce o solapamiento entre hospederos humanos y animales a nivel global. El objetivo de la presente investigación es caracterizar aislamientos obtenidos a partir de heces de origen animal que podrían actuar como reservorio de resistencia a los antimicrobianos (RAM). Mediante el uso de técnicas de cultivo, PCR, ribotipificación y prueba de susceptibilidad a los antimicrobianos (PSA), se caracterizaron 10 aislamientos no toxigénicos de C. difficile. Todos ellos fueron identificados como RT596, una cepa que ha sido previamente documentada en animales y humanos. Además, los aislamientos revelaron cuatro perfiles de multidrogoresistencia (MDR). Nuestros hallazgos constituyen la primera caracterización a nivel regional de un genotipo no toxigénico, con potencial zoonótico y MDR. Se plantea la posibilidad de que, debido a la falta de inclusión de la PSA en los algoritmos de diagnóstico actuales o a su circulación en ambientes hospitalarios, este genotipo pueda actuar como un vector de MDR.

Examinar

Envíos recientes