32 resultados
Resultados de la búsqueda
Mostrando1 - 10 de 32
- ÍtemAcceso Abierto
Genomics of novel influenza A virus (H18N12) in bats, Caribe Colombia(2025-12-01) Mattar,Salim; Ramírez González, Juan David; Arrieta, Germán; Hoyos, Richard; Garay, Evelin; Alemán-Santos, Maira; Bertel, Valeria; López, Yesica; Rivero, Ricardo; Gastelbondo-Pastrana, Bertha; Martínez-Bravo, Caty; Echeverri-De la Hoz, DanielInfluenza viruses are highly capable of mutating and adapting in mammalian hosts. While these viruses have been extensively studied in birds, research on their presence in bats has been limited. However, influenza viruses circulating in bats have shown notable molecular divergence. The present study aimed to characterize the phylogenetic, evolutionary, and antigenic relationships of an influenza A virus detected in the fishing bat Noctilio albiventris. As part of a pathogen surveillance study of public health interest, 159 rectal samples were collected from bats in the Colombian Caribbean. The samples were sequenced using RNA-Seq.A genome (eight viral contigs) associated with the Orthomyxoviridae family was identified in a pool. Most segments showed approximately 90% similarity with H18N11, except for the neuraminidase. Analysis of the N protein shows that occupies a basal position relative to the N11 subtype, with its divergence date estimated to be approximately 50 years earlier than the earliest reported N11 sequence. 3D modeling identified three mutations (K363R, T242K, and I139V), which may enhance interaction with the HLA-DR of bats. The analyses and antigenic divergence observed in the N protein of N. albiventris suggests the existence of a new subtype (H18N12) with unknown pathogenicity, which requires further investigation. - ÍtemAcceso AbiertoUn hallazgo que puede cambiar lo que sabemos del dengue en Colombia(2024-03-07) Ramírez González, Juan DavidEl dengue es una vieja amenaza en la salud pública global que arremete por ciclos de forma obstinada en los países tropicales. Da tregua durante algunos años para luego volver con más fuerza en temporadas específicas. 2023, por ejemplo, es uno de esos periodos en los que esta enfermedad transmitida por mosquitos se ha ensañado con Colombia.
- ÍtemAcceso AbiertoSARS-CoV-2 in the Amazon region: A harbinger of doom for Amerindians(2020) Ramírez, Juan David; Sordillo, Emilia Mia; Gotuzzo, Eduardo; Zavaleta, Carol; Caplivski, Daniel; Navarro, Juan-Carlos; Crainey, James Lee; Bessa Luz, Sergio Luiz; Delgado - Noguera, Lourdes; Schaub, Roxane; Rousseau, Cyril; Herrera, Giovanny; Oliveira-Miranda, Maria A; Quispe-Vargas, Maria Teresa; Hotez, Peter J.; Paniz-Mondolfi, Alberto E.A medida que la pandemia del Síndrome Respiratorio Agudo Severo Coronavirus 2 (SARS-CoV-2) continúa expandiéndose, los recursos de atención médica a nivel mundial se han reducido. Ahora, la enfermedad es extendiéndose rápidamente por América del Sur, con consecuencias mortales en áreas con ya sistemas de salud pública debilitados. La región amazónica es particularmente susceptible a la devastación generalizada de la enfermedad por coronavirus 2019 (COVID-19) debido a sus habitantes amerindios nativos inmunológicamente frágiles y vulnerabilidades epidemiológicas. Aquí, nosotros discutir la situación actual y el impacto potencial de COVID-19 en la región amazónica y cómo una mayor propagación de la ola epidémica podría resultar devastadora para muchas personas amerindias que viven en la selva amazónica
- ÍtemAcceso AbiertoGenomic epidemiology supports multiple introductions and cryptic transmission of Zika virus in Colombia(2019) Black, Allison; Moncla, Louise H.; Laiton-Donato, Katherine; Potter, Barney; Pardo, Lissethe; Rico, Angelica; Tovar, Catalina; Rojas, Diana P.; Longini, Ira M.; Halloran, M. Elizabeth; Peláez-Carvajal, Dioselina; Ramírez, Juan David; Mercado-Reyes, Marcela; Bedford, TrevorBACKGROUND: Colombia was the second most affected country during the American Zika virus (ZIKV) epidemic, with over 109,000 reported cases. Despite the scale of the outbreak, limited genomic sequence data were available from Colombia. We sought to sequence additional samples and use genomic epidemiology to describe ZIKV dynamics in Colombia. METHODS: We sequenced ZIKV genomes directly from clinical diagnostic specimens and infected Aedes aegypti samples selected to cover the temporal and geographic breadth of the Colombian outbreak. We performed phylogeographic analysis of these genomes, along with other publicly-available ZIKV genomes from the Americas, to estimate the frequency and timing of ZIKV introductions to Colombia. RESULTS: We attempted PCR amplification on 184 samples; 19 samples amplified sufficiently to perform sequencing. Of these, 8 samples yielded sequences with at least 50% coverage. Our phylogeographic reconstruction indicates two separate introductions of ZIKV to Colombia, one of which was previously unrecognized. We find that ZIKV was first introduced to Colombia in February 2015 (95%CI: Jan 2015 - Apr 2015), corresponding to 5 to 8 months of cryptic ZIKV transmission prior to confirmation in September 2015. Despite the presence of multiple introductions, we find that the majority of Colombian ZIKV diversity descends from a single introduction. We find evidence for movement of ZIKV from Colombia into bordering countries, including Peru, Ecuador, Panama, and Venezuela. CONCLUSIONS: Similarly to genomic epidemiological studies of ZIKV dynamics in other countries, we find that ZIKV circulated cryptically in Colombia. More accurately dating when ZIKV was circulating refines our definition of the population at risk. Additionally, our finding that the majority of ZIKV transmission within Colombia was attributable to transmission between individuals, rather than repeated travel-related importations, indicates that improved detection and control might have succeeded in limiting the scale of the outbreak within Colombia.
- ÍtemAcceso AbiertoThe epidemiology of Chagas disease in the Americas(2024-09-01) Cucunubá, Z. M.; Gutiérrez-Romero, S. A.; Ramírez González, Juan David; Velásquez-Ortiz, N.; Ceccarelli, S.; Parra-Henao, G.; Abad-Franch, F.Chagas disease is a complex parasitic zoonosis that still threatens public health across the Americas. Initiatives to control Trypanosoma cruzi transmission via blood transfusion and non-native triatomine-bug vectors have yielded crucial advances
- ÍtemAcceso AbiertoTaxonomy, diversity, temporal and geographical distribution of Cutaneous Leishmaniasis in Colombia: A retrospective study(2016) Ramírez, Juan David; Hernández, Carolina; León, Cielo M.; Ayala Sotelo, Martha Stella; Flórez, Carolina; González, CamilaLeishmaniases are tropical zoonotic diseases, caused by kinetoplastid parasites from the genus Leishmania. New World (NW) species are related to sylvatic cycles although urbanization processes have been reported in some South American Countries such as Colombia. Currently, few studies show the relative distribution of Leishmania species related to cutaneous Leishmaniasis (CL) in South America due to the lack of accurate surveillance and public health systems. Herein, we conducted a systematic estimation of the Leishmania species causing CL in Colombia from 1980 to 2001 via molecular typing and isoenzymes. A total of 327 Leishmania isolates from humans, sandflies and reservoirs were typed as L. panamensis 61.3% (201), L. braziliensis 27.1% (88), L. lainsoni 0.6% (2), L. guyanensis 0.9% (3), L. infantum chagasi 4% (12), L. equatoriensis 0.6% (2), L. mexicana 2.1% (8), L. amazonensis 2.8% (9) and L. colombiensis 0.6% (2). This is the first report of two new Leishmania species circulating in Colombia and suggests the need to convince the Colombian government about the need to deploy and standardize tools for the species identification to provide adequate management to individuals suffering this pathology.
- ÍtemAcceso AbiertoMolecular Testing of Environmental Samples as a Potential Source to Estimate Parasite Infection(2024-10-01) Mejia, Rojelio; Slatko, Barton; Almazan, Cristina; Cimino, Ruben; Krolewiecki, Alejandro; Montellano Duran, Natalia; Jacob Edwin Valera Aspetty; Vargas, Paola Andrea; Oliveira Amorim, Chiara Cássia; Geiger, Stefan Michael; Toshio Fujiwara, Ricardo; Ramírez González, Juan David; Llangarí-Arizo, Luz Marina; Guadalupe, Irene; Villanueva-Lizama, Liliana E.; Cruz-Chan, Julio Vladimir; Ojeda, María Leticia; Mereles Aranda, Eva; Ocampos Benedetti, Sandra; Dalí Camones, Maritza; RiveraEddyson MontalvoSabino; Wetzel, Eric J. ; Montalvo Sabino, Eddyson ; Cooper, Philip J.We discuss the potential usefulness of molecular testing of soil, dust, and water samples to detect medically important parasites, and where such testing could be used to supplement stool sampling in humans. A wide variety of parasites including protozoa and helminths, many of which are zoonotic, have an important infection reservoir in the environment. In some cases, this environmental period is essential for further parasite development. We describe the progress in implementing methods for the molecular detection of these parasites in soil across eight collaborating centers in Latin America and represent a variety of potential applications in improving our understanding of parasite epidemiology and mapping, surveillance, and control of these parasites. This methodology offers new opportunities for improving our understanding of a wide variety of parasites of public health importance and novel tools for their control.
- ÍtemAcceso AbiertoLobomycosis in Amazon Region, Bolivia, 2022(2024-12-01) Méndez, Maria I.; Colanzi, Rony; Suárez, Jose A.; Penagos, Homero; Hernández, Carolina; Garcia-Redondo, Ruth; Ramírez González, Juan David; Paniz-Mondolfi, AlbertoWe report a patient with lobomycosis caused by Paracoccidioides loboi fungi in the Andes-Amazon region of Bolivia. We examined clinical, epidemiologic, and phylogenetic data and describe potential transmission/environmental aspects of infection. Continued surveillance and identification of lobomycosis cases in South America are crucial to prevent the spread of this disease.
- ÍtemAcceso AbiertoLa respuesta inmune de algunas especies del género Rhodnius modifica la circulación de genotipos de Trypanosoma cruzi y T. rangeli en varias regiones de América Latina(2023-12-20) Ramírez González, Juan David; Hernández, Diana Carolina; Guhl, Felipe; Urrea, Daniel Alfonso; Carranza, Julio César; Meneses, Arlid; Suárez, Yazmín; Barbosa, Hamilton Julián; Vallejo, Gustavo AdolfoLa respuesta inmune de los triatominos se expresa en la hemolinfa, la saliva y el intestino a través de los eicosanoides, el sistema profenoloxidasa, los péptidos antimicrobianos, las especies reactivas de oxígeno, las reactivas de nitrógeno y los factores de la microbiota intestinal. El género Rhodnius, conformado por 21 especies organizadas en tres grupos, pallescens, pictipes y prolixus, actúan como vectores de Trypanosoma cruzi y T. rangeli en diferentes regiones de Latinoamérica. En varios estudios se ha reportado la actividad lítica en la hemolinfa y en las glándulas salivales de Rhodnius prolixus y R. robustus, del grupo prolixus, contra algunos genotipos de T. cruzi y T. rangeli. Esta actividad lítica no se ha observado en las especies estudiadas de Triatoma y Panstrongylus ni en R. pallescens, R. colombiensis y R. ecuadoriensis del grupo pallescens, o R. pictipes del grupo pictipes. En estudios proteómicos de la hemolinfa y las glándulas salivales de R. prolixus y R. colombiensis se detectaron diferencias en proteínas de respuesta inmune que estarían asociadas con la actividad lítica. Esta respuesta inmune, además de los factores de la microbiota intestinal, la distribución geográfica de los vectores, y los genotipos del parásito, ha llevado a plantear la hipótesis de que el grupo prolixus está conformado por vectores con factores inmunes que determinan la transmisión selectiva de algunos genotipos de T. cruzi y T. rangeli, lo que ha modificado la distribución geográfica de estos parásitos en el continente americano. En esta revisión de la interacción parásito-vector, se presentan resultados publicados entre 1982 y 2023 para respaldar la hipótesis planteada.
- ÍtemAcceso AbiertoTaxonomy, evolution, and biogeography of the rhodniini tribe (Hemiptera: Reduviidae)(2020) Galindo Hernández, Carolina; da Rosa, João Aristeu; Vallejo, Gustavo A.; Guhl, Felipe; Ramírez, Juan DavidThe Triatominae subfamily includes 151 extant and three fossil species. Several species can transmit the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, significantly impacting public health in Latin American countries. The Triatominae can be classified into five tribes, of which the Rhodniini is very important because of its large vector capacity and wide geographical distribution. The Rhodniini tribe comprises 23 (without R. taquarussuensis) species and although several studies have addressed their taxonomy using morphological, morphometric, cytogenetic, and molecular techniques, their evolutionary relationships remain unclear, resulting in inconsistencies at the classification level. Conflicting hypotheses have been proposed regarding the origin, diversification, and identification of these species in Latin America, muddying our understanding of their dispersion and current geographic distribution. Clarifying these factors can help for the design of vector control strategies. The aim of this review is to depict the different approaches used for taxonomy of the Rhodniini and to shed light on their evolution and biogeography. © 2020 by the authors.
