Artículos Científicos

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The lipopolysaccharide of brucella abortus BVRS/BVRR mutants contains lipid a modifications and has higher affinity for bactericidal cationic peptides
(American Society for Microbiology, 2005-08) Manterola, Lorea; Moriyón, Ignacio; Moreno, Edgardo; Sola-Landa, Alberto; Weiss, David S.; Koch, Michel H. J.; Howe, Jörg; Brandenburg, Klaus; López-Goñil, Ignacio
The two-component BvrS/BvrR system is essential for Brucella abortus virulence. It was shown previously that its dysfunction abrogates expression of some major outer membrane proteins and increases bactericidal peptide sensitivity. Here, we report that BvrS/BvrR mutants have increased surface hydrophobicity and susceptibility to killing by nonimmune serum. The bvrS and bvrR mutant lipopolysaccharides (LPSs) bound more polymyxin B, chimeras constructed with bvrS mutant cells and parental LPS showed augmented polymyxin B resistance, and, conversely, parental cells and bvrS mutant LPS chimeras were more sensitive and displayed polymyxin B-characteristic outer membrane lesions, implicating LPS as being responsible for the phenotype of the BvrS/BvrR mutants. No qualitative or quantitative changes were detected in other envelope and outer membrane components examined: periplasmic (1-2) glucans, native hapten polysaccharide, and phospholipids. The LPS of the mutants was similar to parental LPS in O-polysaccharide polymerization and fine structure but showed both increased underacylated lipid A species and higher acyl-chain fluidity that correlated with polymyxin B binding. These lipid A changes did not alter LPS cytokine induction, showing that in contrast to other gram-negative pathogens, recognition by innate immune receptors is not decreased by these changes in LPS structure. Transcription of Brucella genes required for incorporating long acyl chains into lipid A (acpXL and lpxXL) or implicated in lipid A acylation control (bacA) was not affected. We propose that in Brucella the outer membrane homeostasis depends on the functioning of BvrS/BvrR. Accordingly, disruption of BvrS/BvrR damages the outer membrane, thus contributing to the severe attenuation manifested by bvrS and bvrR mutants.
Some digenetic trematodes of the olive ridley sea turtle, Lepidochelys olivacea (Testudines, Cheloniidae) in Costa Rica
(Parasitological Institute of SAS, 2007-01) Santoro, M.; Morales, Juan Alberto
Se recuperaron tres especies de digeneos, incluyendo un gorgoderidae (Plesiochorus cymbiformis) de la vejiga urinaria, un plagiorchiidae (Enodiotrema megachondrus) del duodeno y un pachypsolidae (Pachypsolus irroratus) del estómago, de dos de tres tortugas golfinas (Lepidochelys olivacea) varadas a lo largo de la costa del Pacífico de Costa Rica. Todos los trematodos representan nuevos registros de localidad. Se describieron cambios histopatológicos asociados con huevos de duelas cardiovasculares (Digenea, Spirorchiidae) en los pulmones, el bazo y el intestino de una sola tortuga.
Redescription of Charaxicephaloides polyorchis Groschaft and Tenora 1978 (Digenea: Pronocephalidae) from the green turtle Chelonia mydas in Costa Rica
(Parasitological Institute of SAS, 2009-06-20) Santoro, M.; Brandmayr, P.; Greiner, E.; Morales, Juan Alberto; Rodríguez-Ortíz, B.
Charaxicephaloides polyorchis (Groschaft y Tenora, 1978) se reescribe con base en especímenes recolectados del estómago de tortugas verdes Chelonia mydas en Costa Rica. Nuestros especímenes coinciden con la descripción original, basada en cuatro aletas caudales de la misma especie hospedadora de la costa noroeste de Cuba. Nuestra redescripción proporciona una nueva gama de variaciones y aporta nueva información sobre esta especie. Este es solo el segundo registro de C. polyorchis en tortugas verdes.
Tyr→Trp-substituted peptide 115-129 of a Lys49 phospholipase A2 expresses enhanced membrane-damaging activities and reproduces its in vivo myotoxic effect
(Elsevier B.V., 1999-11-09) Lomonte, Bruno; Pizarro-Cerda, Javier; Angulo, Yamileth; Gorvel, Jean-Pierre; Moreno, Edgardo
Myotoxin II is a group II Lys49 phospholipase A2 (PLA2) isolated from the venom of the snake Bothrops asper. Previous studies on a synthetic peptide derived from its heparin-binding, cationic/hydrophobic sequence 115^129 demonstrated a direct functional role of this particular region in the in vitro cytolytic and bactericidal actions of the protein. Nevertheless, no significant myonecrosis has been observed after local intramuscular injection of peptide 115-129 (p115-129) in mice. Since the membrane-damaging action of p115-129 was proposed to depend on its amphiphilic character, the present study examined the effects of substituting its cluster of three tyrosine residues by tryptophan residues, on its toxic/pharmacological activities in vitro and in vivo. This substitution resulted in a drastic enhancement of the membrane-damaging activities of the peptide (p115-W3), together with the clear expression of myotoxic activity in vivo. Both the heparin-binding and antigenic characteristics of p115-129 were essentially conserved in p115-W3, suggesting that the modification did not lead to radical structural alterations. In addition to myotoxicity, cytotoxicity, and bactericidal action, p115-W3 exerted edema-forming activity in the mouse footpad assay. Thus, the synthetic 13-mer p115-W3 reproduced all the known toxic effects of myotoxin II. In spite of its potent membrane-damaging actions, p115-W3 did not acquire direct hemolytic activity upon mouse erythrocytes, an effect which is not present in myotoxin II, but that has been ascribed to the presence of tryptophan in other cationic, membrane-damaging peptides such as mellitin from bee venom. The myotoxic activity of p115-W3 herein described constitutes the first example of a short, PLA2-based linear synthetic peptide with the ability to reproduce this effect of a parent protein in vivo. This finding is in clear support of the proposed relevance of the C-terminal region 115^129 in all the membrane-damaging mechanisms exerted by myotoxin II, including the myotoxic mechanism.
Objective evaluation of the response to perineural analgesia of the deep branch of the lateral plantar nerve and intraarticular analgesia of the tarsometatarsal joint in horses with suspected proximal metatarsal pain using body-mounted inertial sensors
(Elsevier Inc., 2018) LEELAMANKONG, P.; Estrada McDermott, Roberto J.; Rungsri, Porrakote; Wolfgang, Stäcker; Müller, Carolin D.V.S; Lischer, Christoph
Perineural analgesia of the deep branch of the lateral plantar nerve (DBLPN block) and intraarticular analgesia of the tarsometatarsal joint (TMT block) are commonly used to differentiate pain originating from the distal tarsal and the proximal metatarsal areas in horses. However, both analgesic techniques have recently been subjected to close scrutiny, with questions raised as to their efficacy. The purpose of this study is to undertake an objective assessment of the effect of both diagnostic analgesia techniques on hindlimb lameness using a body-mounted inertial sensor system (Lameness Locator; Equinosis LLC, Columbia, MO). Horses with chronic hindlimb lameness were instrumented with inertial sensors measuring vertical pelvic asymmetry in millimeters and underwent a routine lameness examination including diagnostic analgesia. Twenty-seven horses showing an improvement in lameness after the DBLPN block were selected for the study. These horses underwent the TMT block on the following day. The change in vertical pelvic asymmetry after the DBLPN block was compared to the change following the TMT block. Of 27 horses, 17 showed improvement after the DBLPN block but not after the TMT block (group 1). The other 10 horses showed improvement in lameness after both analgesic techniques (group 2). The DBLPN block and the TMT block desensitized different structures in more than half of the horses. However, the possibility that both analgesic techniques can desensitize the same structures due to either the diffusion of the anesthetic agent or of an inadvertent injection still remains.
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.
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.
The SAPUVETNET Projects: experiences of intersectoral collaboration and research/training in Veterinary Public Health across Latin America and Europe
(Societa Italiana di Medicina Tropicale, 2011-07) De Meneghi, Daniele; Bert, Elena; Porporato, Piercarlo; Pattono, Daniele; Cediel, Natalia; Vilhena, Manuela; Padre, Ludovina; Arroube, Sofia; Baltasar, Patricia; Custodio, Angelo; Villamil, Luis Carlos; Romero, Jaime; Mutis, Claudia; Sommerfelt, Irma; Lopez, Clara; Van Knapen, Frans; Keessen, Liny; De Rosa, Mauro; Rosenfeld, Carla; Leguia, Guillermo; Falcon, Nestor; Torres, Miguel; Romero, Paul; Caballero, Magaly; Quiros, Jorge; Quiros, Ligia; Muñoz, Lohendy; Fonseca, Adolfo; Duttman, Christiane; Jiron, William; Sheleby, Jessica; Guitian, Javier; Alonso, Silvia; Gimeno, Olga; Simon, Mari Carmen; Ortega, Carmelo; Gil, Andres; Rios, Cristina; Pfuetzenreiter, Marcia; Gorniak, Silvana; Renteria, Tomas; Pujol, Carolina; Tinoco, Luis; Hoet, Armando; De Sousa, Paulo Cesar; Estol, Leopoldo; Dobosch, Dora; Parrilla, Guillermo; Vargas, Raul; De Balogh, Katinka
SAPUVETNET is the acronym of "Red de Salud Publica Veterinaria/Network of Veterinary Public Health", a series of projects co-financed under the EU ALFA program, aimed to support an International network on Veterinary Public Health (VPH) constituted by Faculties of Veterinary Medicine from Latin-America (LA) and Europe (EU) (http://www.sapuvetnet.org). Since its start in 2002, SAPUVETNET has been continuously growing and expanding, and now it also includes several International collaborating institutions/organizations. The SAPUVETNET projects have envis-aged a series of objectives/activities aimed to promote and enhance VPH research/training and intersectoral collaboration across LA and EU. Project partners use a mail-list and distance learning platforms (e.g. Moodle, Colibri) to organize common teaching activities. Major results so far achieved are: harmonisation/development of a common VPH curriculum; creation of common modules/courses on selected VPH topics; use of innovative teaching methods, based on problem solving approach/case studies; publication of videos (DVDs) and self-learning program (CD-ROM) on meat inspection/hygiene (in 3 languages); development of an on-line VPH teaching Manual (beta version in Spanish); organization of e-conferences on upcoming VPH issues; publication of a new International VPH Journal "Una Salud/One Health/Uma Saude" (in 3 languages); exchanges of teachers/researchers (e.g. bilateral visits LA-EU-LA) and coordinating meetings; participation in and/or organization of VPH seminars/congresses/conferences at National and International level; publication of scientific and popular articles on VPH issues related to project activities. SAPUVETNET didactic tools have been and/or are being tested/used by partner faculties/universities and other teaching institutions. Didactic material can be freely circulated and distributed, and can be used for distance learning, be modified/adapted to the local context of any country/geographical area, even outside LA and EU.
Forensic investigation of a 1986 outbreak of osteopetrosis in commercial brown layers reveals a Novel Avian Leukosis Virus–Related Genome
(Asociación Estadounidense de Patólogos Aviares, 2010-09-01) Barboza, Taylor; Ramírez, Marcia; Hafner, Scott; Cheng,A., Sunny; Zavala, Guillermo
Se sabe que el virus de la leucosis aviar (VLA) causa varias enfermedades neoplásicas en pollos, como linfomas de células B, mielocitomas, eritroblastosis y otros tipos de neoplasia, incluyendo la osteopetrosis. En este trabajo, describimos la identificación de secuencias únicas de ADN proviral relacionadas con el VLA en un hueso de pollo archivado afectado con osteopetrosis. El hueso osteopetrótico se obtuvo de una gallina ponedora marrón afectada de 46 semanas de edad durante un brote de osteopetrosis en Costa Rica en 1986. El análisis del ADN proviral en el hueso osteopetrótico de 23 años de edad reveló secuencias exógenas únicas relacionadas con el VLA, denominadas CR-1986 (Costa Rica, 1986). Las repeticiones terminales largas (LTR) 5′ y 3′ en el ADN proviral fueron idénticas entre sí. Las regiones U3 en las LTR fueron las más similares a las secuencias equivalentes en el VLA-J, mientras que la región U5 fue idéntica a las secuencias endógenas conocidas del VLA-E. La proteína de envoltura CR-1986 predicha fue más similar a la envoltura del virus asociado a la mieloblastosis tipo 1 (MAV-1), aunque el porcentaje de similitud de la secuencia de aminoácidos con MAV-1 fue bajo (90,4%). Las regiones variables e hipervariables de gp85 mostraron varias mutaciones en comparación con cepas representativas de ALV. La proteína de envoltura gp37 (transmembrana o TM) mostró tres mutaciones de leucina a serina que pueden representar cambios importantes en la conformación de esta proteína, un hallazgo que se está investigando actualmente. Varios eventos de recombinación pueden haber contribuido a la aparición de CR-1986 porque cada segmento analizado fue similar a un ALV diferente. CR-1986 puede representar un ALV único basado en características distintivas de su proteína de envoltura predicha en comparación con los ALV informados previamente.
Dual Mycotic Infection in a Chicken
(Asociación Estadounidense de Patólogos Aviares, 1985-04) Mendoza, Leonel; Fonseca, Edwin
Se demostro histopatologicamente una doble infecci6n micotica causada por Aspergillus fumigatus e hifas gruesas semejantes al grupo de los zigomicetes en el pulmon de un pollo de 12 semanas de edad. A. fumigatus fue aislado, pero no se observó el crecimiento de zigomicetes.
Favus in a Fighting cock Caused by Microsporum Gallinae
(Asociación Americana de Patólogos Aviares, 1984-07) Mendoza, Leonel; Fonseca, Edwin
Se reporta por primera vez en Costa Rica la presencia de tiña en pollos. El diagnóstico se hizo en un gallo de pelea de un año de edad que presentó lesiones alrededor de la cresta. El agente etiológico fué aislado y clasificado como Microsporum gallinae. El gallo afectado se recuperó con el uso de tolnaftate y griseofulvina como tratamientos local y oral respectivamente.
Actividad ovárica y tasa de gestación en novillas suplementadas en el Trópico Húmedo de Costa Rica
(Universidad de Chile, 2014) Jiménez J., Alejandro; Estrada Koning, Sandra; Pablos H., José; Galina H., Carlos; Galindo B., Jaime
Se determinó el efecto de la suplementación sobre la actividad ovárica y tasa de gestación en novillas Bosindicus (n=41) nulíparas de dos a tres años, divididas aleatoriamente en dos grupos: el suplementado (GS n=21) con un concentrado comercial (13,5% PC, 2,850 Mcal ED/kg MS) a razón del 1% del peso; con un periodo de 15 días de adaptación más 30 de suplementación y el testigo (GNS n=20). Ambos pastando Estrella Africana (Cynodonplestostachium), Ratana (Ischaemumindicum) y Tanzania (Panicummaximum); agua y sales minerales ad libitum). Las hembras se sincronizaron con Crestar® y servidas con dos toros de fertilidad probada. El diseño experimental fue al azar utilizando el programa estadístico JMP 10® de SAS Institute Inc. para el análisis. La condición corporal (CC) y grasa dorsal (GD) no son diferentes (P>0.05) así como los porcentajes entre grupos para actividad ovárica (ciclicidad y estructuras ováricas), tasa de preñez, los eventos de ciclicidad y gestación a lo largo del tiempo (P>0.05). La estimación de ocurrencia de la gestación en función del suplemento y la ciclicidad, según el modelo: Gest = f(GEST, CYC, TRAT) no mostró efecto del tratamiento (P>0.05) pero si significancia en los momentos de detección de la gestación (día 33 y día 45 respectivamente) entre grupos (P< 0.0001). En conclusión, el método de suplementación ensayado no tuvo mayor efecto sobre las variables estudiadas.
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.
Retrospective and prospective perspectives on zoonotic brucellosis
(Frontiers, 2014-05-13) Moreno, Edgardo
Members of the genus Brucella are pathogenic bacteria exceedingly well adapted to their hosts. The bacterium is transmitted by direct contact within the same host species or accidentally to secondary hosts, such as humans. Human brucellosis is strongly linked to the management of domesticated animals and ingestion of their products. Since the domestication of ungulates and dogs in the Fertile Crescent and Asia in 12000 and 33000 ya, respectively, a steady supply of well adapted emergent Brucella pathogens causing zoonotic disease has been provided. Likewise, anthropogenic modification of wild life may have also impacted host susceptibility and Brucella selection. Domestication and human influence on wild life animals are not neutral phenomena. Consequently, Brucella organisms have followed their hosts’ fate and have been selected under conditions that favor high transmission rate. The “arm race” between Brucella and their preferred hosts has been driven by genetic adaptation of the bacterium confronted with the evolving immune defenses of the host. Management conditions, such as clustering, selection, culling, and vaccination of Brucella preferred hosts have profound influences in the outcomeof brucellosis and in the selection of Brucella organisms. Countries that have controlled brucellosis systematically used reliable smooth live vaccines, consistent immunization protocols, adequate diagnostic tests, broad vaccination coverage and sustained removal of the infected animals. To ignore and misuse tools and strategies already available for the control of brucellosis may promote the emergence of new Brucella variants. The unrestricted use of low-efficacy vaccines may promote a “false sense of security” and works towards selection of Brucella with higher virulence and transmission potential.
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.
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.
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.
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.
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.
Reactivation of hidden-latent Brucella infection after doxycycline and streptomycin treatment in mice
(American Society for Microbiology, 2024-02) Sancho Sánchez, Eugenia; García Arteaga, Kimberly; Granados Chinchilla, Fabio; Artavia, Graciela; Alfaro-Alarcon, Alejandro; Villalobos Villalobos, Andrés; Bouza Mora, Laura; Suárez Esquivel, Marcela; Chacón Díaz, Carlos; Guzman-Verri, Caterina; Moreno, Edgardo; BARQUERO-CALVO, ELIAS
Brucellosis has therapeutic challenges due to 3%–15% relapses/therapeutic failures (R/TF) after antibiotic treatment. Therefore, determining the antibiotic concentration in tissues, the physiopathological parameters, and the R/TF after treatment is relevant. After exploring different antibiotic quantities, we found that a combined dose of 100 µg/g of doxycycline (for 45 days) and 7.5 µg/g of streptomycin (for 14 days), respectively, achieved therapeutic levels of more than fourfold minimum inhibitory concentrations (MICs) against Brucella abortus in the spleen, liver, bone marrow, and plasma of mice, causing minimal pathophysiological effects. After 30 days of infection, mice received antibiotics, and ematological, histopathological, biochemical, and immunological analyses were performed. After antibiotic therapy, the pathological, hematological, immunological, and physiological profiles paralleled those described in human brucellosis. Treatment lowered antibody titers, reduced proinflammatory cytokines, and reduced inflammation in the target organs for a protracted period. No bacteria were detected in tissues 8 weeks after treatment, suggesting complete recovery. However, despite high doxycycline and streptomycin concentrations in tissues, relapses appeared in 100% of the animals after 182 days post-infection, estimated by the bacterial counts and PCR from organs. This proportion contrasts with the 15% R/TF observed in humans after antibiotic treatments. None of the B. abortus isolated from relapses showed augmented MICs or mutations coding for antibiotic resistance in chromosomalrelevant regions. We discuss whether our findings constitute a general phenomenon or differences in the exhaustive screening method for bacteria detection related to the murine model. Along these lines, we envision likely mechanisms of bacterial persistence in tissues after antibiotic treatment.

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