Browsing by Author "Costales Cordero, Jaime Alfredo"
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2b-RAD genotyping for population genomic studies of Chagas disease vectors: Rhodnius ecuadoriensis in Ecuador(2017) Costales Cordero, Jaime Alfredo; Ocaña Mayorga, Sofía Beatriz; Villacis Salazar, Anita Gabriela; Yumiseva Marín, César Alberto; Jaime Alfredo Costales Cordero, Sofía Beatriz Ocaña Mayorga, Anita Gabriela Villacis Salazar y César Alberto Yumiseva MarínRhodnius ecuadoriensis is the main triatomine vector of Chagas disease, American trypanosomiasis, in Southern Ecuador and Northern Peru. Genomic approaches and next generation sequencing technologies have become powerful tools for investigating population diversity and structure which is a key consideration for vector control. Here we assess the effectiveness of three different 2b restriction site-associated DNA (2b-RAD) genotyping strategies in R. ecuadoriensis to provide sufficient genomic resolution to tease apart microevolutionary processes and undertake some pilot population genomic analyses.Item Open Access Activity of novel aromatic compounds against Trypanosoma cruzi(PUCE - Quito, 2023) Dávalos Ojeda, Lesley Sharon; Costales Cordero, Jaime AlfredoBackground: The parasitic hemoflagellate protozoan Trypanosoma cruzi is the causative agent of Chagas Disease (CD), a tropical infection affecting mainly low-income population segments in Latin America, where it is one of the leading parasitic infections. Nifurtimox (NFX) and benznidazole (BNZ) are the only two drugs currently approved to treat infections with T. cruzi; however, they frequently induce serious side effects while their efficacy is unsatisfactory. Therefore, identification of novel compounds displaying specific activity against T. cruzi is of high interest, as a basis for development of new drugs to treat CD.Methods. Seven novel aromatic compounds were evaluated. In vitro activity against the recombinant Tulahuen ß-gal strain of T. cruzi was measured employing colorimetric assays for ß-gal activity. Cytotoxicity against cultured mammalian cells was evaluated via resazurin reduction assays. BNZ was used as a reference drug.Results: All studied compounds presented activity against T. cruzi in vitro; however, five of them also induced significant host-cell damage, suggesting their toxicity is not specific. Compounds 3K and 3L showed no cytotoxicity measurable up to 100 µM concentrations, while displaying IC50 values against T. cruzi of 1.464 and 2.717 µM, respectively. In the same assay, BNZ, displayed an IC50 value of 1.558 µM and no cytotoxicity at concentrations up to 100 µM.Conclusions: Two compounds evaluated in the study are selectively toxic against intracellular T. cruzi amastigotes in vitro and did not display cytotoxic activity against mammalian cells. Their IC50 values are comparable to those obtained for BNZ, the reference drug. Novel compounds with specific anti-T. cruzi activity can be further explored in the search for options for CD treatment.Item Open Access Análisis de la dinámica de transmisión vectorial de la enfermedad de Chagas en las provincias de Manabí y Loja mediante la caracterización de subtipos de Trypanosoma cruzi(PUCE - Quito, 2011) Zurita Lagos, Alejandra Patricia; Costales Cordero, Jaime AlfredoEl protozoario parásito Trypanosoma cruzi, agente causal de la Enfermedad de Chagas (ECh), presenta una alta variabilidad genética. Existen seis linajes de T. cruzi, denominados TcI a TcVI. En este estudio se analizaron aislados provenientes de las provincias de Loja y Manabí, y se encontró que el linaje predominante es TcI. La variabilidad de TcI fue analizada mediante Tipificación de Secuencias Multilocus (MLST), empleando un panel de 7 genes (coar, pdh, rl-gtp, sttp-frag2, gp, tcsodb, tcosda), que en combinación produjeron buen poder discriminatorio (DP=1). En ambas provincias, el análisis permite distinguir dos poblaciones, una conformada predominantemente por parásitos provenientes de hospederos colectados en el hábitat de domicilio-peridomicilio y la otra conformada predominantemente con los del hábitat silvestre. Nuestros resultados sugieren que existe un flujo genético limitado entre las dos poblaciones. Estos resultados indican que los ciclos de transmisión del parásito tienen un importante impacto en la divergencia genética en las poblaciones tanto de Manabí y como de Loja, y que posiblemente los hospederos (reservorios y vectores) jueguen un rol importante en la dispersión de T. cruzi entre los ciclos de transmisión domiciliar-peridomicilar y silvestre. Todos estos factores deben tomarse en cuenta para desarrollar medidas de control para la ECh, en el Ecuador...Item Unknown Análisis genético del locus DFNB1 en individuos ecuatorianos con hipoacusia no sindrómica recesiva(PUCE - Quito, 2014) Beaty Herrera, Doyle Edmond; Costales Cordero, Jaime AlfredoSe ha estimado que el 60% de casos con hipoacusia se dan por factores genéticos; dentro de los factores genéticos, la hipoacusia no sindrómica recesiva es la forma más común de hipoacusia hereditaria. Debido a esto, se decidió realizar un análisis genético del locus DFNB1 con muestras tomadas de diferentes provincias del Ecuador. En este estudio únicamente se encontraron mutaciones en el gen GJB2 locus DFNB1A. Ningún individuo de la población total tenía la deleción del(GJB6-D13S1830) del locus DFNB1B. Las siete mutaciones patogénicas halladas en este estudio fueron: Q7X (C19T), 35delG, V27I (G79A), R32L (G95T), W77R (T229C), R143W (C427T), S199F (C596T) y N206S (A617G); además de estas, se identificó al polimorfismo no patogénico V27I. Considerando todas las variaciones, en la población de estudio se encontró un total de 104 alelos mutados (estos vienen hacer los alelos totales). La variación más común en la población total fue el polimorfismo benigno V27I, del cual se encontraron 61 alelos, equivalente al 58,9% del total de los alelos mutados detectados en los loci estudiados (alelos totales). La segunda variación más común fue Q7X, presente en el 18,3% (19 alelos) de los alelos totales. Al considerar únicamente las mutaciones patogénicas (todas excepcionando V27I), Q7X viene a ser la más común. Dieciséis genotipos fueron hallados en los individuos afectos (aquellos que sufren de hipoacusia), sanos y familiares (parientes de los afectos). Entre los individuos afectos se encontraron 13 individuos en heterocigosis compuesto con dos mutaciones patogénicas. El genotipo Q7X/V27I/R32L, el más común, se encontró en cuatro individuos afectos. Este análisis genético permitió la identificación de ocho variaciones alélicas del gen GJB2 y, posteriormente, relacionar la clínica de 13 de los 26 individuos afectos con genotipos homocigoto recesivos o heterocigoto compuestos con dos mutaciones patogénicas. Se confirma que la mutación Q7X provoca hipoacusia no sindrómica y no hipoacusia sindrómica como previamente sugerido. Al considerar lo común que resultó ser la mutación Q7X existe la posibilidad que sea una mutación predominante en la población ecuatoriana; sin embargo, existe la necesidad de ampliar el estudio para poder definir con mayor certeza cuan fuerte es la presencia de la mutación Q7X, y de las demás, en la población ecuatorianaItem Unknown Analytical validation of quantitative Real - Time PCR methods for quantification of trypanosoma cruzi DNA in blood samples from chagas disease patients(2015-09) Costales Cordero, Jaime Alfredo; Schijman, Alejandro G.An international study was performed by 26 experienced PCR laboratories from 14 countries to assess the performance of duplex quantitative real-time PCR (qPCR) strategies on the basis of TaqMan probes for detection and quantification of parasitic loads in peripheral blood samples from Chagas disease patients. Two methods were studied: Satellite DNA (SatDNA) qPCR and kinetoplastid DNA (kDNA) qPCR. Both methods included an internal amplification control. Reportable range, analytical sensitivity, limits of detection and quantification, and precision were estimated according to international guidelines. In addition, inclusivity and exclusivity were estimated with DNA from stocks representing the different Trypanosoma cruzi discrete typing units and Trypanosoma rangeli and Leishmania spp. Both methods were challenged against 156 blood samples provided by the participant laboratories, including samples from acute and chronic patients with varied clinical findings, infected by oral route or vectorial transmission. kDNA qPCR showed better analytical sensitivity than SatDNA qPCR with limits of detection of 0.23 and 0.70 parasite equivalents/mL, respectively. Analyses of clinical samples revealed a high concordance in terms of sensitivity and parasitic loads determined by both SatDNA and kDNA qPCRs. This effort is a major step toward international validation of qPCR methods for the quantification of T. cruzi DNA in human blood samples, aiming to provide an accurate surrogate biomarker for diagnosis and treatment monitoring for patients with Chagas disease.Item Unknown Cell invasion by trypanosoma cruzi and the type i interferon response(2017) Costales Cordero, Jaime Alfredo; Jenny Telleria y Michel TibayrencThe life cycle of Trypanosoma cruzi is digenetic, comprising developmental stages in an invertebrate host (vector) as well as a mammalian host. Well over a 100 species of blood feeding triatomines may harbor T. cruzi, while a variety of wild and domestic mammals, in addition to humans, can serve as the mammalian hosts. In the triatomine vector, only extracellular developmental forms of the parasite occur. Epimastigotes, which are slender flagellated replicative forms, attach to the lumen of the vector digestive tract, multiply in the anterior midgut, and differentiate into metacyclic trypomastigotes in the hindgut. Metacyclic trypomastigotes, which are capable of infecting the mammalian host, are released along with the triatomine feces, from where they are involuntarily placed in the bite wound or the mucous membranes of the eyes by the bitten individual.Item Unknown Chagas Disease Has Not Been Controlled in Ecuador(2016-06-28) Costales Cordero, Jaime Alfredo; Costales Cordero, Jaime AlfredoA recent study by Cartelle Gestal et al. reported an analysis of data from the Ministry of Public Health on the epidemiological situation of neglected tropical diseases in Ecuador. Based on a misleading definition of Chagas disease cases not corresponding to that of the Ministry of Public Health, the authors concluded that the government had mounted successful control campaigns, and as a result Chagas disease (among others) had been effectively controlled as no cases in children under age five had been reported since 2009. Ecuador is thus identified as one of the first countries to control Chagas disease. While we certainly agree that efforts have been made in terms of Chagas disease surveillance and control campaigns in Ecuador, a more comprehensive analysis of available data, from both the Ministry of Public Health and the literature, provides a very different picture, and the claim that Chagas disease is controlled made by Cartelle Gestal et al. seems largely inadequate and sends an equivocal message which can undermine current control efforts. As mentioned in this study, the Chagas disease control program in the country was formally established in 2003–2004, in response to recommendations from a technical consultation through PAHO/WHO [3] and field studies [4,5]. This consultation and data provided a baseline to prioritize activities. It reported a national seroprevalence of Trypanosoma cruzi infection of 1.38%, corresponding to 165–170,000 seropositive patients in the country. Three regions were prioritized: the coastal region (seroprevalence of 1.99%), the Amazon region (1.75%) and the southern highlands (0.65%). The incidence was estimated at 36 cases/100,000 inhabitants/year, resulting in 4,400 new cases each year.Item Unknown Chagas disease reactivation in a heart transplant patient infected by domestic Trypanosoma cruzi discrete typing unit I (TcIDOM)(2015-08-25) Costales Cordero, Jaime Alfredo; Costales Cordero, Jaime AlfredoBackground: Trypanosoma cruzi, causative agent of Chagas disease, displays high intraspecific genetic diversity: six genetic lineages or discrete typing units (DTUs) are currently recognized, termed TcI through TcVI. Each DTU presents a particular distribution pattern across the Americas, and is loosely associated with different transmission cycles and hosts. Several DTUs are known to circulate in Central America. It has been previously suggested that TcI infection is benign and does not lead to chronic chagasic cardiomyopathy (CCC). Findings: In this study, we genotyped T. cruzi parasites circulating in the blood and from explanted cardiac tissue of an El Salvadorian patient who developed reactivation Chagas disease while on immunosuppressive medications after undergoing heart transplant in the U.S. as treatment for end-stage CCC. Parasite typing was performed through molecular methods (restriction fragment length polymorphism of polymerase reaction chain amplified products, microsatellite typing, maxicircle sequence typing and low-stringency single primer PCR, [LSSP-PCR]) as well as lineage-specific serology. We show that the parasites infecting the patient belong to the TcI DTU exclusively. Our data indicate that the parasites isolated from the patient belong to a genotype frequently associated with human infection throughout the Americas (TcIDOM). Conclusions: Our results constitute compelling evidence in support of TcI DTU’s ability to cause end-stage CCC and help dispel any residual bias that infection with this lineage is benign, pointing to the need for increased surveillance for dissemination of this genotype in endemic regions, the USA and globally.Item Unknown Congenital Chagas Disease in the ecuadorian amazon: maternal screening at delivery and evaluation of risk factors associated with vector exposure(2019) Costales Cordero, Jaime Alfredo; Costales Cordero, Jaime AlfredoCongenital infection with Trypanosoma cruzi remains a major route for Chagas disease transmission in endemic and non-endemic regions. We evaluated an intervention strategy aimed to detect congenital Chagas disease cases at a major hospital in the Ecuadorian Amazon via cord blood analysis at the time of delivery. All women giving birth at the hospital during the study period (191) were invited to participate. Among them, two (1.0%) did not adjust to the inclusion criteria and four (2.1%) declined to participate in the study, showing the intervention had good acceptability among the mothers. It was possible to obtain cord blood samples during 146 of the deliveries, and only one woman was found to be seropositive, without evidence of transmission to the newborn at delivery or 8 months later. In addition, sociodemographic and economic characterization of the study population revealed that few women had previous knowledge about Chagas disease (16.1%) whereas more than half (62.5%) recognized the vector. Recognizing the vector and having seen it indoors were associated with women from rural families, involved in agriculture, and hunting in the forest. Interestingly, most women (87.3%) reported having easy access to Ecuador’s national health system, suggesting serological screening during prenatal visits would be of value in this province. With a proper prenatal screening system in place, cord blood screening would allow for timely detection of T. cruzi infection in newborns from both seropositive women and the minority (2.1%) of women who do not comply with prenatal care visits.Item Unknown Culture-free genome-wide locus sequence typing (GLST) provides new perspectives on Trypanosoma cruzi dispersal and infection complexity(2020-12-16) Costales Cordero, Jaime Alfredo; Ocaña Mayorga, Sofía Beatriz; Costales Cordero, Jaime AlfredoAnalysis of genetic polymorphism is a powerful tool for epidemiological surveillance and research. Powerful inference from pathogen genetic variation, however, is often restrained by limited access to representative target DNA, especially in the study of obligate parasitic species for which ex vivo culture is resource-intensive or bias-prone. Modern sequence capture methods enable pathogen genetic variation to be analyzed directly from host/vector material but are often too complex and expensive for resource-poor settings where infectious diseases prevail. This study proposes a simple, cost-effective ‘genome-wide locus sequence typing’ (GLST) tool based on massive parallel amplification of information hotspots throughout the target pathogen genome. The multiplexed polymerase chain reaction amplifies hundreds of different, user-defined genetic targets in a single reaction tube, and subsequent agarose gel-based clean-up and barcoding completes library preparation at under 4 USD per sample. Our study generates a flexible GLST primer panel design workflow for Trypanosoma cruzi, the parasitic agent of Chagas disease. We successfully apply our 203-target GLST panel to direct, culture-free metagenomic extracts from triatomine vectors containing a minimum of 3.69 pg/μl T. cruzi DNA and further elaborate on method performance by sequencing GLST libraries from T. cruzi reference clones representing discrete typing units (DTUs) TcI, TcIII, TcIV, TcV and TcVI. The 780 SNP sites we identify in the sample set repeatably distinguish parasites infecting sympatric vectors and detect correlations between genetic and geographic distances at regional (< 150 km) as well as continental scales. The markers also clearly separate TcI, TcIII, TcIV and TcV + TcVI and appear to distinguish multiclonal infections within TcI. We discuss the advantages, limitations and prospects of our method across a spectrum of epidemiological research.Item Unknown Distinct proteomic profiles are associated with Trypanosoma cruzi I strains displaying high/low infectivity towards mammalian cells in vitro(PUCE - Quito, 2018) Rodríguez Riglos, Camila Cilveti; Costales Cordero, Jaime AlfredoCausative agent of Chagas disease, Trypanosoma cruzi, has a digenetic life cycle, 24 comprising life stages in invertebrate and mammalian hosts. In mammalian hosts, the 25 parasites multiply intracellularly; therefore, the process of cellular invasion is required for 26 life cycle completion. T. cruzi is a genetically diverse species and six different genetic 27 lineages are currently recognized (TCI-TCVI), TCI being the most widespread and 28 genetically variable. TcI strains present significant differences in their ability to invade 29 mammalian cells in vitro, which may be rooted both in genetic differences as well as in 30 protein expression levels. We report the identification of sets over and underexpressed of 31 2-DE spots statiscally associated with high and low infectivity strains. Proteins associated 32 with high infectivity strains identified through mass spectrometry showed a major 33 presence of proteins related to the cytoskeleton and motility of the parasite, which 34 suggests that the more infective strains could be more motile than the less infective ones. 35 Additionally, high infective strain proteins associated with antioxidant activity were also 36 present, which may be related to more aggressive invasive patterns. Ultimately, 37 identification of specific proteins and pathways associated to the ability of 38 trypomastigotes to infect mammalian cells will open up the possibility of functional 39 confirmation through overexpression and knockout experiments and may unveil potential 40 drug and vaccine targets.Item Unknown Diversidad genética del gen del mini- exón en Trypanosoma cruzi y Trypanosoma rangeli en dos localidades de la provincia de LojaCostales Cordero, Jaime AlfredoEl Centro de Investigación en Enfermedades Infecciosas y Crónicas (CIEIC) organiza el “IV Encuentro Internacional de Investigación en Enfermedades Infecciosas y Medicina Tropical”, del 13 al 15 de Junio, en la Pontificia Universidad Católica del Ecuador (PUCE), en Quito. El objetivo de este congreso es reunir a la comunidad científica para impulsar y generar la oportunidad de crear redes colaborativas entre las distintas instituciones que trabajan en investigación de enfermedades infecciosas.Item Unknown Efecto antimicrobiano de péptidos sintéticos obtenidos a partir de la piel de anuros ecuatorianos sobre bacterias multirresistentes(PUCE - Quito, 2023) Nuñez Santana, Camila Micaela; Costales Cordero, Jaime AlfredoLos antibióticos tradicionales están perdiendo efectividad frente a bacterias multirresistentes, las cuales se producen por el uso excesivo e inapropiado de agentes antibacterianos y por una selección natural de cepas bacterianas resistentes. Estas bacterias son cada vez más comunes y representan una amenaza para la salud mundial. El Sistema Mundial de Vigilancia de la Resistencia a los Antimicrobianos emitió un informe en 2018 que mostraba que las principales bacterias que presentan una mayor resistencia a los antimicrobianos son Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae y Mycobacterium tuberculosis. Esto ha planteado la necesidad de encontrar nuevas soluciones para combatir estas infecciones. En este estudio, se analizó la actividad de dos péptidos antimicrobianos frente a S. aureus resistente a la oxacilina (C-ORSA), E. coli productora de betalactamasas de espectro extendido (BLEE), K. pneumoniae portadora del gen KPC (K. pneumoniae carbapenemasa) y Serratia marcescens. Estos péptidos antimicrobianos son una alternativa innovadora para el tratamiento de infecciones causadas por bacterias multirresistentes. Los péptidos antimicrobianos son moléculas naturales o sintéticas que poseen una amplia actividad inhibitoria contra una gran variedad de microorganismos, incluyendo bacterias, virus, hongos y protozoos. Además, existe una baja probabilidad de que las bacterias desarrollen resistencia en comparación con los antibióticos tradicionales. El estudio utilizó la metodología de la Mínima Concentración Inhibitoria (MIC) y una prueba hemolítica. Se realizaron ensayos en placas de microdilución de 96 pocillos, con 10 diluciones de los péptidos, siendo 512 µg/ml la más alta y 1 µg/ml la más baja. Se realizaron 7 repeticiones por triplicado de cada ensayo para asegurar la repetitividad y la reproducibilidad de los resultados. Los hallazgos demostraron que los péptidos Dermaseptina sp7 y Dermaseptina sp10 exhibieron actividad inhibitoria frente a S. aureus (C-ORSA) y E. coli (BLEE), a concentraciones de 64 32 µg/m y 32 µg/m de MIC respectivamente, mientras que sobre K. pneumoniae y S. 10 marcescens no mostraron esta actividad. Estos péptidos no son citotóxicos para los eritrocitos. Estos resultados sugieren que la Dermaseptina SP7 y la Dermaseptina SP10 podrían ser una opción terapéutica prometedora para tratar infecciones causadas por bacterias S. aureus y E. coli multirresistentes.Item Open Access Estudio preliminar de la prevalencia de cardiopatía chagásica en la provincia de Manabí, Ecuador y caracterización molecular y biológica de aislados TcI de Trypanosoma cruzi(PUCE - Quito, 2011) Zurita Leal, Andrea Cristina; Costales Cordero, Jaime AlfredoLa enfermedad de Chagas (ECh), causada por el protozoario flagelado Trypanosoma cruzi, se caracteriza por ocasionar cardiopatías y daños en el sistema digestivo. En el Ecuador, está presente en la Costa, Amazonía y en las regiones subtropicales de la Sierra; se estima que aproximadamente 165 a 170 mil personas se encuentran infectadas con T. cruzi en el país. Sin embargo, a pesar de que los daños cardiacos son el más común y perjudicial efecto de la enfermedad de Chagas, en nuestro país se desconoce la prevalencia de cardiopatía chagásica. Por ello, se realizó un estudio piloto sobre la seroprevalencia de la enfermedad de Chagas en las unidades de cardiología de hospitales de la provincia de Manabí. Se buscó caracterizar algunas de las propiedades biológicas de los parásitos que circulan en nuestro país, como características morfológicas, infectividad in vitro, y capacidad de inducir cambios en la expresión génica de las células infectadas in vitro. En el estudio piloto sobre cardiopatía chagásica en Manabí, encontramos que alrededor del 2% de pacientes que participaron en el estudio son reactivos en pruebas serológicas para Chagas. Ni los cardiólogos ni los pacientes estaban al tanto de esta infección. Esto demuestra la necesidad de estudios más amplios sobre cardiopatía chagásica en nuestro país. Se deseaba aislar parásitos de estos pacientes para estudiar sus propiedades biológicas...Item Open Access Evaluación de la actividad antimicrobiana de péptidos sintéticos derivados de la piel de anfibios ecuatorianos(PUCE - Quito, 2023) Herrera Acurio, Francis Andrea; Costales Cordero, Jaime AlfredoLas infecciones causadas por microorganismos multirresistentes representan un grave problema de salud pública en todo el mundo. Entre las bacterias que producen estas infecciones se encuentran Staphylococcus aureus resistente a la oxacilina (C-ORSA), Escherichia coli productora de betalactamasas de espectro extendido (BLEE), Klebsiella pneumoniae productora de carbapenemasa (KPC) y Serratia marcescens. La resistencia de estas bacterias a los antibióticos existentes evidencia la necesidad de buscar nuevas alternativas de tratamiento. Los péptidos antimicrobianos (AMPs) son un conjunto de biomoléculas con alto potencial debido a sus mecanismos de acción contra bacterias. En este artículo se evaluó la efectividad de los péptidos Dermaseptina SP5 y SP9 derivados de la piel de Agalychnis spurrelli frente a aislados clínicos de las bacterias resistentes antes mencionadas. Se determinó la Concentración Mínima Inhibitoria (MIC) de estos péptidos. Además, se realizó una prueba hemolítica para determinar el grado de hemólisis de cada uno de los péptidos. Los resultados mostraron que los péptidos no tuvieron efecto inhibitorio en S. aureus, K. pneumoniae y S. marcescens. Sin embargo, se observó un efecto inhibitorio en E. coli, con una dependencia de la concentración de los péptidos. Los resultados sugieren que la resistencia observada puede deberse a estrategias desarrolladas por las bacterias para evitar la actividad de los AMPs. También se evaluó el grado de hemólisis de Dermaseptina SP9, demostrando su capacidad para no dañar las membranas celulares. En general, se concluyó que las Dermaseptinas SP5 y SP9 tienen potencial como agentes antimicrobianos, pero se necesita más investigación para comprender sus mecanismos de acción y efectividad contra una amplia gama de bacterias resistentes.Item Open Access Evaluation of the activity of bispirazoles against recombinant Trypanosoma cruzi strains expressing ß-galactosidase(PUCE - Quito, 2023) Galarza Jarrín, Ambar Nicol; Costales Cordero, Jaime AlfredoBackground: Nifurtimox and benznidazole are the only drugs currently approved to treat Chagas disease, caused Trypanosoma cruzi. However, they display unsatisfactory efficacy and induce undesirable side effects. Therefore, identifying new compounds with specific activity against T. cruzi is of great interest.Methods. The in vitro activity of twenty-five bispirazoles was evaluated against intracellular amastigotes of the recombinant Tulahuen ß-gal strain of T. cruzi. Their cytotocicity against mammalian cells was evaluated via resazurin reduction assays. BNZ was used as a reference drug.Results: In the initial two repetitions of the screen, one bispirazole (2X) presented specific in vitro activity against T. cruzi, with an IC50 value of 3,416 µM and no measurable cytotoxicity at concentrations up 100 µM. BNZ, employed as reference drug, displayed a IC50 of 4,23 µM and a CC50 up to 100 µM. Compound 2X´s activity was not reproducible in subsequent replicates.Conclusions: One evaluated compound was selectively toxic against intracellular T. cruzi amastigotes in vitro and did not show cytotoxic activity against mammalian cells. Its IC50 value is comparable to those obtained for BNZ, the reference drug. Further studies are warranted to confirm the anti-T. cruzi activity of compound 2X.Item Open Access Evaluation of the in vitro anti-T.cruzi activity of four antimicrobial peptides from Ecuadorian anurans(PUCE - Quito, 2023) Ramos Dussling, Eloy Dylon; Costales Cordero, Jaime AlfredoBackground: Chagas disease (CD) caused by Trypanosoma cruzi, is considered the most important parasitic disease in the Americas. It is estimated to affect approximately 8 million people, 30% of which will develop the debilitating and potentially fatal health complications as a result. Infection by T. cruzi can be cured if treatment with benznidazole or nifurtimox is administered shortly after the infection occurs. However, treatment efficacy decreases over time, making treatment of chronic Chagas disease challenging. Additionally, these drugs frequently induce side effects. Antimicrobial peptides (AMPs), biologically active molecules produced by organisms through their innate immune system, are of considerable interest for developing new antimicrobial therapies. Methods. The anti-T. cruzi activity of four antimicrobial peptides derived from the gliding tree frog, Agalychnis spurrelli, was studied. Synthetic versions of adenoregulin- AS1 (ADN-AS1), dermatoxin-AS1 (DTX-AS1), dermaseptin-SP9 (DRS-SP9), and dermaseptin-SP10 (DRS-SP10) were tested in vitro against trypomastigotes of the recombinant Tula-ß-gal T. cruzi strain via colorimetric assays. The cytotoxicity of the peptides against mammalian cells was also evaluated, using rezasurin reduction assays. Results: The four studied peptides exhibited varying degrees of activity against T. cruzi tripomastigotes, the parasite forms infective to mammals, including humans. Three peptides (DTX-AS1, DRS-SP10, and ADN-AS1) displayed activity against the parasite (EC50 = 0,35, 1,21 and, 1,58 µM, respectively) with limited cytotoxic effects over mammalian host cells. DRS-SP9, conversely, displayed much lower (EC50 = 22, 91µM) activity. Conclusions: These findings suggest the studied peptides are active against T. cruzi trypomastigotes. Dermatoxina-AS1 (DTX-AS1) displays the most specific activity against the parasite. Although our data suggest peptides are lytic for the parasite, additional studies are required to clarify their mechanism of action.Item Open Access Factores sociales asociados con la utilización de los servicios de atención prenatal en Ecuador(2016-11) Costales Cordero, Jaime Alfredo; Grijalva Cobo, Mario JavierObjetivos: La atención prenatal es uno de los pilares de la salud pública y permite el acceso a intervenciones tales como la prevención de la transmisión materno-infantil del VIH y de la sífilis congénita. Este artículo tiene como objetivo describir los factores sociales asociados con la utilización de los servicios de atención prenatal en Ecuador. Métodos. Entre 2011 y 2012, se realizó un análisis de la información procedente de las historias clínicas y de la entrevista a las participantes, que integraron una muestra probabilística a nivel nacional de 5 998 mujeres atendidas por parto o aborto en 15 servicios sanitarios en Ecuador con el objetivo de estimar la prevalencia de VIH, sífilis, enfermedad de Chagas y la cobertura de atención prenatal. Resultados. El estudio mostró que 94,1% de las mujeres había acudido a algún control prenatal, pero la asistencia al menos a cuatro controles fue 73,1%. Se encontró que el menor nivel educativo, el mayor número de embarazos, la ocupación en el sector agrícola o ganadero y la pertenencia a los grupos étnicos indígena, afroecuatoriano u otros minoritarios fueron factores asociados con la falta de uso (ningún control prenatal) o al uso inadecuado de la atención prenatal (menos de cuatro controles o primer control después de las 20 semanas de gestación) en Ecuador. Conclusiones. Estos resultados apuntan a la persistencia de desigualdades marcadas en el acceso y en la utilización de servicios de atención prenatal atribuibles a factores socioeconómicos y a la necesidad de fortalecer las estrategias para su abordaje para alcanzar la meta de la cobertura universal de atención prenatalItem Metadata only Fatal acute Chagas disease by Trypanosoma cruzi DTU TcI, Ecuador(2020-02) Costales Cordero, Jaime Alfredo; Costales Cordero, Jaime AlfredoBackground: Chagas disease is caused by the haemoflagellate protozoan Trypanosoma cruzi. Currently, T. cruzi recognizes seven discrete typing units (DTUs): TcI to TcVI and Tcbat. The genetic diversity of T. cruzi is suspected to influence the clinical outcome. Acute clinical manifestations, which include myocarditis and meningoencephalitis, are sometimes fatal; occur most frequently in children and in immunocompromised individuals. Acute disease is often overlooked, leading to a poor prognosis. Case presentation: A 38-year-old man from a subtropical area of the Andes mountains of Ecuador was hospitalized after 3 weeks of evolution with high fever, chills, an enlarged liver, spleen, and lymph nodes, as well as facial edema. ECG changes were also observed. T. cruzi was identified in blood smears, culture and amplification of DNA by PCR. Tests for anti-T. cruzi IgG and IgM and HIV were negative. Molecular typing by restriction fragment length polymorphism (PCR-RFLP) determined the parasite to DTU TcI. In the absence of a timely anti-T. cruzi medication, the patient died. Conclusions: This is a case of severe pathogenicity and the virulence of a DTU TcI strain in an adult patient. The severe acute Chagas disease was probably overlooked due to limited awareness and its low incidence. Our findings suggest that T. cruzi DTU TcI strains circulating in Ecuador are capable of causing fatal acute disease. Early diagnosis and prompt treatment is of paramount importance to avoid fatalities in acute infections.Item Open Access Genetic diversity of the Trypanosoma cruzi and Trypanosoma rangeli mini-exon gene in two localities of Southern Ecuador(PUCE - Quito, 2018) Maiguashca Sánchez, Jalil; Costales Cordero, Jaime AlfredoTrypanosoma cruzi, causative agent of Chagas Disease, and Trypanosoma 25 rangeli, are both protozoan parasites endemic to Latin America, including Ecuador. 26 T. cruzi shows high molecular and morphological heterogeneity and six lineages or 27 DTU’s are currently recognized. In Ecuador, TcI predominates while zymodeme III, 28 corresponding to what is currently TcIV, was previously reported by a single study. 29 T. rangeli, although nonpathogenic to humans, is a species of interest due to its 30 sympatric distribution with T. cruzi and confounding effect in Chagas Disease 31 diagnosis. In the present study, we isolated DNA of intestinal contents of triatomines 32 belonging to two communities of Southern Ecuador. Infection status determined by 33 kinetoplast-minicircle PCR was contrasted with results yielded by PCR amplification 34 of the non-transcribed region of the mini-exon gene. For disambiguation of the 35 results obtained, amplified fragments from the non-transcribed region of the mini-36 exon gene were sequenced using an Illumina MiSeq platform. We evaluated genetic 37 variability in terms of richness and diversity at a population level for both parasites 38 using Operational Taxonomic Units. T. cruzi genetic diversity was found to be 39 significantly larger in adult female vectors as compared to the nymphal stages. 40 Additionally, NGS revealed 21 mixed infections between TcI and T. rangeli, and the 41 presence of DTU TcIV in 7 samples, (a novel record in Southern Ecuador), which 42 the PCR-based methods were not able to detect. This suggests that the PCR-based 43 methods are not reliable as molecular tools for identification of mixed infections. 44 Furthermore, parasite populations present in only one of the two studied localities 45 were not found, suggesting active parasite dispersal over the study area. Our results highlight the value of NGS methodologies to clarify the population dynamics of 47 triatomines and inform control strategies.