Artículos Científicos

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

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American crocodiles (Crocodylus acutus: Reptilia: Crocodilidae) visiting the facilities of a freshwater aquaculture of the Northern Pacific region, Costa Rica, carry tetracycline-resistant Escherichia coli
(Frontiersin.org, 2024-04-05) Mateus Vargas, Rafael Hernán; Arias Pérez, Verónica; Sandoval Hernández, Iván; Hammerl, Jens Andre; Barquero-Calvo, Elías
Apex predators are exposed to antimicrobial compounds and resistant microbes, which accumulate at different trophic levels of the related ecosystems. The study aimed to characterize the presence and the antimicrobial resistance patterns of fecal Escherichia coli isolated from cloacal swab samples obtained from wild-living American crocodiles (Crocodylus acutus) (n = 53). Sampling was conducted within the distinctive context of a freshwater-intensive aquaculture farm in Costa Rica, where incoming crocodiles are temporarily held in captivity before release. Phenotypic antimicrobial susceptibility profiles were determined in all isolates, while resistant isolates were subjected to whole-genome sequencing and bioinformatics analyses. In total, 24 samples contained tetracycline-resistant E.coli (45.3%). Isolates carried either tet(A), tet(B), or tet(C) genes. Furthermore, genes conferring resistance to ß-lactams, aminoglycosides, fosfomycin, sulfonamides, phenicol, quinolones, trimethoprim, and colistin were detected in single isolates, with seven of them carrying these genes on plasmids. Genome sequencing further revealed that sequence types, prevalence of antibiotic resistance carriage, and antibiotic resistance profiles differed between the individuals liberated within the next 24 h after their capture in the ponds and those liberated from enclosures after longer abodes. The overall presence of tetracycline-resistant E. coli, coupled with potential interactions with various anthropogenic factors before arriving at the facilities, hinders clear conclusions on the sources of antimicrobial resistance for the studied individuals. These aspects hold significant implications for both the aquaculture farm’s biosecurity and the planning of environmental monitoring programs using such specimens. Considering human-crocodile conflicts from the One Health perspective, the occurrence of antimicrobial resistance underscores the importance of systematical surveillance of antibiotic resistance development in American crocodiles.
Compressive behavior of SLA open-cell lattices: a comparison between triply periodic minimal surface gyroid and stochastic structures for artificial bone
(ELSEVIER, 2024-11-11) Araya, Miguel; Murillo, Josué; Vindas Bolaños, Rafael; Guillen, Teodolito
This study evaluates the compressive properties of stereolithography (SLA) fabricated open-cell lattices, specifically triply periodic minimal surface (TPMS) gyroid and stochastic structures, for artificial bone applications. Two resins, Standard White and BioMed Amber, were tested across four relative densities (0.2, 0.3, 0.4, 0.5). Mechanical characterization of horse tuber coxae trabecular bone used as a biological comparator showed an average elastic modulus of 0.05 GPa and a yield strength of 3.369 MPa. Gyroid structures exhibited higher elastic modulus and yield strengths, with BioMed Amber gyroid at a density of 0.5, achieving an elastic modulus of 0.623 GPa and yield strength of 14.149 MPa. Stochastic structures showed lower and more variable mechanical properties. The highest yield strength for stochastic structures was observed in BioMed Amber at a density of 0.5 (14.199 MPa). Comparative analysis indicated that high-performing synthetic structures approach the lower bounds of natural bone properties. Using a field-driven design approach, variable relative density structures were developed to emulate the mechanical properties of natural bone. SEM analysis provided insights into failure mechanisms, highlighting the impact of relative density on structural integrity and material ductility. This research supports the development of 3D-printed bone-like structures as viable substitutes for cadaveric specimens in preclinical tests, with implications for material science and orthopedic applications.
Detection of Vector Transmitted Zoonotic Pathogens in Nonhuman Primates in the Manuel Antonio National Park and Surrounding Areas of Costa Rica
(Mary Ann Liebert, Inc, 2025) Rojas-Sánchez, Ernesto; Mata-Masís, María; Calderón-Bailey, Jennifer; Zuniga-Moya, Maria J.; Solorzano-Morales, Antony; Vega-Benavides, Karen; Jiménez-Soto Mauricio; Dolz, Gaby
Background: The Manuel Antonio National Park (MANP) and its surrounding areas in Costa Rica are home toendangered non-human primates (NHPs), including Saimiri oerstedii citrinellus and Cebus imitator, that coexistin close contact with humans and domestic animals. Such interactions may facilitate the transmission of vector-borne zoonotic diseases. This study aimed to investigate the presence of selected vector-transmitted pathogens ofzoonotic relevance in NHPs from this region.Methods: Between 2021 and 2022, 40 free-ranging NHPs (19 C. imitator, 19 S. oerstedii citrinellus, 2 Alouattapalliata) were sampled in MANP and surrounding areas. Blood samples were tested for Trypanosoma spp.,Plasmodium spp., Mycoplasma spp., and arboviruses including dengue virus (DENV), chikungunya virus (CHIKV),Zika virus (ZIKV), Venezuelan equine encephalitis virus (VEEV), and West Nile virus (WNV). Molecular analyseswere conducted using PCR and RT-qPCR protocols, with sequencing for species conﬁrmation.Results: Eight of 40 NHPs (20.0%) tested positive for at least one pathogen. Trypanosoma minasense was conﬁrmedby sequencing in three C. imitator (16.7%). Plasmodium spp. was detected in one C. imitator and one A. palliata (5.0%),though species-level identiﬁcation was unsuccessful. One C. imitator tested positive for CHIKV (Ct 36.8), representingthe ﬁrst PCR-conﬁrmed case of CHIKV in NHPs in Central America. Two C. imitator were positive for Mycoplasmaspp. (11.1%). No co-infections were observed. All animals were negative for DENV, ZIKV, VEEV, and WNV.Conclusions: This study provides the ﬁrst molecular evidence of CHIKV infection in NHPs in Costa Rica andhighlights the circulation of Trypanosoma spp., Plasmodium spp., and Mycoplasma spp. in wild primates fromMANP. These ﬁndings emphasize the need for a One Health approach to surveillance, particularly in regionswhere human–wildlife interactions are frequent. Longitudinal and serological studies are recommended to assessthe potential reservoir role of NHPs and their implications for public health and conservation.
Estrategias para el manejo de heridas crónicas complicadas con biopelícula de bacterias multirresistentes en equinos: revisión bibliográfica, diagnóstico y protocolo de tratamiento
(Universidad Nacional, Costa Rica, 2024) Estrada McDermott, Juan Manuel; Vicente Salazar, Yayo; Vargas Arrieta, José; Alpízar Boza, Adriana; Rubí Chacón, Randall; Alfaro Umaña, Edgar; Estrada Pull, Tiffany; Rojas Sánchez, Ernesto; Vindas Bolaños, Rafael; BARQUERO-CALVO, ELIAS; Muñoz Vargas, Lohendy; Estrada Umaña, Manuel
El propósito de este artículo es discutir algunos hechos relevantes hallados en varios casos clínicos de resistencia antibiótica tratados en equinos con la meta de hacer conciencia sobre el problema, revisar la literatura especializada en el tema y proponer alternativas terapéuticas diferentes al uso de los antibióticos disponibles. El tracto fistuloso ejemplifica una herida crónica y se manifiesta como un túnel subcutáneo con egreso a piel que permite la salida de secreción contaminada. Cuando el tracto está infectado con bacterias multirresistentes y presencia de biopelícula entonces el tratamiento médico es bastante más complicado, prolongado en el tiempo y caro debido al costo de procedimientos diagnósticos, manejo veterinario, medicamentos e internamiento hospitalario ocupado en muchos casos, además de que generalmente no se puede efectuar el uso zootécnico esperado para el animal hasta que el mismo sane y su precio se devalúa por la lesión. El rol de las biopelículas bacterianas en heridas con infección crónica es abordado y en vista de la dificultad para identificarlas, se aconseja buscar los signos clínicos específicos sugerentes del problema y aplicar el “Algoritmo Diagnóstico de Percival” para la detección de biopelícula. El tratamiento debería basarse en desbridamiento repetido y aplicación de terapia antimicrobiana tópica, sin recetar antibióticos sistémicos a menos que existan signos de infección generalizada. Se discuten un protocolo de tratamiento para mejorar el manejo de la lesión y la utilización de sustancias antisépticas alternativas a los antibióticos convencionales actuales, además de aplicación de conceptos de UNA SALUD para lidiar con el problema.
In-vivo and ex-vivo evaluation of bio-inspired structures fabricated via PBF-LB for biomedical applications
(Elsevier, 2025-04) Araya, Miguel; Järvenpää, Antti; Rautio, Timo; Vindas Bolaños, Rafael; Estrada McDermott, Roberto; de Ruijter, Mylène
Titanium-based lattice structures have gained significant attention in biomedical engineering due to their potential to mimic bone-like behavior and improve implant performance. This study evaluates the performance of bio-inspired Ti64 TPMS Gyroyd and Stochastic lattice structures fabricated via Powder Bed Fusion-Laser Beam (PBF-LB), focusing on their in-vivo and ex-vivo mechanical and biological responses for biomedical applications. Utilizing an SLM 280 HL printer, samples exhibited notable geometric accuracy essential for mechanical integrity. The study highlights significant mechanical properties and geometric precision improvements achieved through chemical etching. Mechanical characterization revealed that the as-built Gyroid lattice had the highest elastic modulus (3.64 GPa) and yield strength (200.65 MPa), which improved post-etching (3.62 GPa and 219.35 MPa, respectively). The Stochastic lattice demonstrated lower yield strength values post-etching (169.81 MPa). In-vivo analyses in horse models, both structures demonstrated excellent biocompatibility and osseoin-tegration with no adverse inflammatory responses. Ex-vivo push-out tests showed that the chemically etched Gyroid structure achieved the highest resistance to push-out force (1645.407 N) and most significant displacement (2.754 mm), indicating superior energy absorption (4920.425 mJ). These findings underscore the critical influence of microstructural design and surface treatments on implant functionality, offering novel insights into improving biomedical implant performance through lattice architecture and post-processing.
Pathology caused by the trematode circumvitellatrema momota in free-range wild blue-crowned motmots (Momotus momota) in Central America
(American Association of Zoo Veterinarians, 2025) Chaves Hernandez, Aida; Jiménez Rocha, Ana; Quesada Vasquez, Dioney; Lizano Zumbado, Adrián; Martínez, Juan; Jiménez-Soto, Mauricio
Wildlife conservation law in Costa Rica protects common motmots (Momotus momota), limiting the specimens available to study their health and biology. This report describes the finding of the trematode Circumvitellatrema momota in the trachea, air sacs, lung, and celomatic cavity of two free-living M. momota. Histiocytic air sacculitis and pleuritis with granulomas containing trematodes, as well as adhesions between the air sacs and pericardium, were observed. In addition, histiocytic pneumonia, air sacculitis, celomitis, ulcerative tracheitis, and necrotizing histiocytic hepatitis showing intralesional parasites were detected. Eggs with morphology compatible with C. momota were found in the feces of both birds. To our knowledge, this is the first report of C. momota in motmots of Central America. As may be seen in the second case, severe respiratory compromise was possibly affecting the bird’s capacity to fly. Longitudinal studies of the host, parasite, and environment are necessary to understand the implication for C momota infection to the health and survival of the common motmot.
Psittacine beak and feather disease in 2 free-living great green macaws: a case report and literature review
(AAVLD, 2025) Olivares, Roberto W I; Bass, Laura G.; Sáenz Bräutigam, Andrés; Sandí Carmiol, Janet; Villada Rosales, Ana M.; Dolz, Gaby; Solórzano Morales, Antony; Zúñiga Moya, María J.; Granados Solano, Roxana; Mc Hale, Brittany; Zúñiga Cortés, Diego S.; Uzal, Francisco A.
Psittacine beak and feather disease (PBFD) is caused by the psittacine beak and feather disease virus (PBFDV; Circoviridae, Circovirus parrot). This disease affects mainly young captive birds, inducing lesions mainly in the skin adnexa and lymphoid organs. Here we report PBFD in 2 free-living great green macaws (Ara ambiguus). The birds were depressed and had lost feathers and body condition. The diagnosis was confirmed by gross lesions and PCR testing in one bird, and by gross and microscopic lesions, PCR testing, viral sequencing, and in situ hybridization in the other bird. Gross lesions in both birds included mild beak discoloration and feather loss. Microscopic lesions in the bird whose tissues were examined histologically included bronchopneumonia and severe lymphoid depletion with intracytoplasmic and intranuclear botryoid inclusion bodies in the cloacal bursa. Sequences of the viral DNA obtained from paraffin-embedded cloacal bursa tissue had 100% nucleotide and 100% amino acid identity with several strains of PBFDV isolated from captive birds in multiple countries. To our knowledge, PBFD has not been reported previously in free-living great green macaws.
Seroprevalencia de agentes infecciosos que afectan el sistema reproductor de búfalos de agua (Bubalus bubalis), en Costa Rica
(Universidad Nacional, Costa Rica, 2025) Rivera, Josué; Zúñiga, María José; ROMERO-ZUÑIGA, JUAN JOSÉ; Dolz, Gaby
Los búfalos de agua (Bubalus bubalis) son susceptibles a la mayoría de patógenos que afectan a los bovinos, siendo aquellos que ocasionan problemas reproductivos o baja productividad, los que más inciden en la producción pecuaria. Hasta la fecha, en Costa Rica, únicamente se ha determinado la prevalencia de brucelosis. El objetivo de este trabajo fue determinar la seroprevalencia del virus de leucosis bovina (BLV), herpes virus bovino tipo 1 (BHV-1), virus de la diarrea viral bovina (BVDV) y Neospora caninum en búfalos de agua de Costa Rica. Se recolectaron, durante mayo y agosto de 2020, 372 muestras de sangre de individuos mayores a 15 meses edad pertenecientes a 20 fincas de las provincias de Alajuela, Guanacaste, San José, Heredia, Limón y Puntarenas. Las muestras se analizaron mediante técnicas inmunoenzimáticas comerciales (IDVET, Montpellier, Francia). Se determinó la seroprevalencia global, así como a nivel de fincas, de cada agente. Las seroprevalencias globales estimadas para BHV-1, BVDV y N. caninum fueron 54,0%, 41,7%, y 64,3%, respectivamente. Hubo seropositivos a BHV-1, BVDV y N. caninum en todas las provincias analizadas. Las mayores seroprevalencias de BHV-1 se determinaron en Alajuela (65,3%), Heredia (52,8%) y Limón (45,4%); las de BVDV en San José (68,2%) y Alajuela (63,9%), y de N. caninum en San José (86,4%), Alajuela (69,4%), Guanacaste (66,6%) y Limón (61,4%). El 85,0%, 75,0% y 100% de las fincas resultaron positivas a BHV-1, BVDV y N. caninum, respectivamente. En ninguna finca se detectaron animales positivos a BLV. Este es el primer estudio que reporta la seroprevalencia de BHV-1, BVDV y N. caninum en búfalos de agua de Costa Rica. Estos agentes podrían estar ocasionando problemas reproductivos en las fincas, por lo que se recomienda investigar el efecto de estos patógenos tendientes a establecer programas de control y prevención.
The O-Chain of Brucella abortus Lipopolysaccharide Induces SDS-Resistant MHC Class II Molecules in Mouse B Cells
(Elsevier, 1994-09-15) Escola, Jean Michel; Moreno, Edgardo; Chavrier, Philippe; Gorvel, Jean Pierre E.
El LPS es el antígeno más importante de las bacterias Brucella, patógenos intracelulares facultativos gramnegativos que infectan a una gran proporción de animales y humanos en el mundo. Para comprender mejor los mecanismos de respuesta inmunitaria monitoreados por Brucella, se utilizó su LPS como antígeno modelo. Se probó la capacidad de S-LPS, R-LPS, lípido A y cadena O purificados de Brucella abortus para inducir moléculas MHC clase II resistentes a SDS después de la incubación con células de linfoma B murino. El S-LPS y la cadena O dieron una respuesta significativa, lo que sugiere que la cadena O podría inducir una asociación con la propia clase II o podría actuar como transportador de antígenos para unirse a moléculas MHC clase II.
Venezuelan Equine Encephalitis, Peruvian Amazon, 2020
(Center for Diseases Control and Prevention, 2025) Piche-Ovares, María Marta; García Mendoza, Maria Paquita; Moreira Soto, Andres; Fischer, Carlo; Brünink, Sebastian; Figueroa Romero, Maribel Dana; Merino Sarmiento, Nancy Susy; Marcelo Ñique, Adolfo Ismael; Málaga Trillo, Edward; Gatty Nogueir, Miladi; Cabezas Sanchez, César Augusto; Drexler, Jan Felix
We screened 1,972 febrile patients from the Peruvian Amazon in 2020–2021 for Venezuelan equine encephalitis virus (VEEV). Neutralizing antibody detection rate was 3.9%; 2 patients were PCR positive. Genome identity compared to Peru VEEV subtype ID strains was 97.6%–98.1%. Evidence for purifying selection and ancestry ≈54 years ago corroborated VEEV endemicity.
When climate change couples social neglect: malaria dynamics in Panamá
(Center for Diseases Control and Prevention, 2014) Amarilis Hurtado, Lisbeth; Cáceres, Lorenzo; Chaves, Luis Fernando; Calzada, José E
A major challenge of infectious disease elimination is the need to interrupt pathogen transmission across all vulnerable populations. Ethnic minorities are among the key vulnerable groups deserving special attention in disease elimination initiatives, especially because their lifestyle might be intrinsically linked to locations with high transmission risk. There has been a renewed interest in malaria elimination, which has ignited a quest to understand factors necessary for sustainable malaria elimination, highlighting the need for diverse approaches to address epidemiological heterogeneity across malaria transmission settings. An analysis of malaria incidence among the Guna Amerindians of Panama´ over the last 34 years showed that this ethnic minority was highly vulnerable to changes that were assumed to not impact malaria transmission. Epidemic outbreaks were linked with El Nin˜ o Southern Oscillations and were sensitive to political instability and policy changes that did not ensure adequate attention to the malaria control needs of the Gunas. Our results illustrate how the neglect of minorities poses a threat to the sustainable control and eventual elimination of malaria in Central America and other areas where ethnic minorities do not share the benefits of malaria control strategies intended for dominant ethnic groups.

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