Volumen 25 Número 2 by ronald guillermo peláez sánchez

Revista MVZ Córdoba, 2020
Objetivo. Reportar la infección con Leptospira en riñones de murciélagos de Campeche y Yucatán, M... more Objetivo. Reportar la infección con Leptospira en riñones de murciélagos de Campeche y Yucatán, México, a través de la amplificación por PCR de dos fragmentos distintos del gen 16S RNA ribosomal. Materiales y métodos. Se realizaron capturas en un sitio de Campeche y dos de Yucatán. A los murciélagos capturados se les aplicó la eutanasia y se les realizó una necropsia para recolectar tejido renal que se usó en la extracción de ADN total. Se realizaron dos PCR convencionales para la amplificación de los fragmentos de 16S RNA ribosomal. Se obtuvieron las secuencias de algunos productos positivos y se analizaron con herramientas bioinformáticas para identificar la especie infectante de Leptospira. Resultados. Se capturaron 69 murciélagos pertenecientes a cuatro familias y a ocho especies distintas. La familia con mayor diversidad fue Phyllostomidae con cinco especies. La especie con mayor frecuencia de captura fue Artibeus jamaicensis (41, 59.4%). Las PCR arrojaron una frecuencia global de infección de 21.7%. Las especies infectadas fueron A. jamaicensis, Pteronotus parnellii y Chiroderma villosum. El análisis bioinformático arrojó un 99.0% de identidad para Leptospira noguchii, Leptospira borgpetersenii y Leptospira santarosai. Conclusiones. Algunas especies de murciélagos de Yucatán y Campeche son portadores renales de leptospiras patógenas, por lo que podrían participar en el ciclo silvestre de transmisión en la región. La frecuencia de infección encontrada en los riñones de los murciélagos utilizados es mayor en comparación con aquellas obtenidas en otros reservorios de Yucatán y Campeche. Nuevas especies de murciélagos son reportadas como portadores de Leptospira para México.
Papers by ronald guillermo peláez sánchez

Experimental Parasitology, 2007
The course of experimental infection of Swiss mice with 95 sylvatic Trypanosoma cruzi isolates in... more The course of experimental infection of Swiss mice with 95 sylvatic Trypanosoma cruzi isolates included in TCI or TCII genotype was characterized. The purpose was to verify biological properties and its eventual correspondence with original host species, genotype or zymodeme. The isolates of T. cruzi were 100% infective, 55% resulted in patent parasitemia with 69% (36/52) of mortality. A meaningful biological heterogeneity was observed in both, TCI and TCII isolates. TCII isolates resulted in higher patent parasitemia 64% (38/59), in contrast to the 41% TCI infected Swiss mice (14/34). Parasitemia was not always associated to mortality. Higher biological heterogeneity was observed in T. cruzi II isolates derived from L. rosalia from the Atlantic Coastal Rain forest. TCII isolates derived from marsupials resulted in very similar infection profile in Swiss mice.

Revista Médica Hondureña
Worldwide, leptospirosis is the most highly prevalent zoonosis. Although the wide range of clinic... more Worldwide, leptospirosis is the most highly prevalent zoonosis. Although the wide range of clinical manifestations of leptospirosis in humans is well-documented, knowledge of the mechanisms through which this pathogen causes kidney disease remains limited. This narrative review of the scientific literature presents experimental studies of pathophysiology and kidney disease in leptospirosis, both in humans and animals, and the results show that virulence factors are involved in kidney damage by inducing interstitial tubular nephritis, which is the most frequent pathological manifestation, additionally, to the acute non-oliguric renal lesion with hypokalemia, and loss of magnesium and sodium. Finally, it is concluded that in leptospirosis, the initial lesion in the kidney is caused by damage to the cell membrane of the proximal tubular region cells by pathogenic Leptospira virulence factors, thus exacerbating the immune response.

CES Medicina, 2020
La inmunoglobulina A (IgA) es el isotipo de anticuerpo más abundante en los humanos y fundamental... more La inmunoglobulina A (IgA) es el isotipo de anticuerpo más abundante en los humanos y fundamentalmente participa en la defensa contra las infecciones y el desarrollo de la tolerancia inmune en las mucosas. La deficiencia de IgA es la inmunodeficiencia más frecuente en humanos, pero comúnmente es asintomática y transitoria. Para diagnosticarla, se cuantifica la concentración de IgA en sangre y se evalúa la magnitud de su disminución. De acuerdo con esta evaluación se clasifica en deficiencia parcial (DPIgA) o deficiencia total (DTIgA). Adicionalmente, si solo se afectan los niveles de IgA sin alteraciones de otras inmunoglobulinas séricas como IgM e IgG o subclases de inmunoglobulina G, entonces se denomina como deficiencia selectiva de IgA (DSIgA). La deficiencia selectiva de IgA es de mayor relevancia clínica y considerada un error innato de la inmunidad, aunque su etiología aún es desconocida y clínicamente se asocia a infecciones de los tractos respiratorio y gastrointestinal, al...
Proyecto académico sin fines de lucro, desarrollado bajo la iniciativa de acceso abierto
Se describe por primera vez una serie de nueve casos con clinica indicativa de leptospirosis el m... more Se describe por primera vez una serie de nueve casos con clinica indicativa de leptospirosis el municipio Puerto Narino en el departamento Amazonas, Colombia. Se muestran evidencias serologicas de exposicion con Rickettsia del grupo de las fiebres manchadas . Los casos fueron clinicamente considerados como sindrome febril de origen desconocido. Se descarto infeccion por dengue y malaria. El diagnostico de Leptospira se realizo mediante el metodo de reaccion en cadena de la polimerasa en tiempo real. Igualmente, se detecto la presencia de anticuerpos contra rickettsias del grupo de las fiebres manchadas por inmunofluorescencia Indirecta. Finalmente, se realiza revision del tema.

The American Journal of Tropical Medicine and Hygiene, 2017
It is important to identify the circulating Leptospira agent to enhance the performance of serodi... more It is important to identify the circulating Leptospira agent to enhance the performance of serodiagnostic tests by incorporating specific antigens of native species, develop vaccines that take into account the species/serovars circulating in different regions, and optimize prevention and control strategies. The objectives of this study were to develop a polymerase chain reaction (PCR)-high-resolution melting (HRM) assay for differentiating between species of the genus Leptospira and to verify its usefulness in identifying unknown samples to species level. A set of primers from the initial region of the 16S ribosomal gene was designed to detect and differentiate the 22 species of Leptospira. Eleven reference strains were used as controls to establish the reference species and differential melting curves. Twenty-five Colombian Leptospira isolates were studied to evaluate the usefulness of the PCR-HRM assay in identifying unknown samples to species level. This identification was confirmed by sequencing and phylogenetic analysis of the 16S ribosomal gene. Eleven Leptospira species were successfully identified, except for Leptospira meyeri/ Leptospira yanagawae because the sequences were 100% identical. The 25 isolates from humans, animals, and environmental water sources were identified as Leptospira santarosai (twelve), Leptospira interrogans (nine), and L. meyeri/L. yanagawae (four). The species verification was 100% concordant between PCR-HRM and phylogenetic analysis of the 16S ribosomal gene. The PCR-HRM assay designed in this study is a useful tool for identifying Leptospira species from isolates.

Memórias do Instituto Oswaldo Cruz, 2016
The region of Antioquia in northeastern Colombia has the highest number of reported leptospirosis... more The region of Antioquia in northeastern Colombia has the highest number of reported leptospirosis cases in the country. It also shows high seroprevalence indexes in the general population and socio-environmental conditions favourable for the transmission of the disease between humans and animals. In this study, 25 Leptospira isolates from Colombia's Antioquia department were identified to the species level as L. santarosai (12), L. interrogans (9) and L. meyeri (4) using phylogenetic analysis of the Amidohydrolase gene. Typing at the serovar level was performed using multilocus sequence typing (MLST) and monoclonal antibodies. The serovars Canalzonae, Babudieri, Alice, Beye, and Copenhageni have been identified as causing human or animal infections in Antioquia, Colombia. The four environmental isolates were not identified to the serovar level. L. santarosai serovar Canalzonae and Alice were identified as new etiologic agents of human leptospirosis in Antioquia, Colombia. This paper reports species and serovars that were previously unknown in the region.

Universidad y Salud
Introducción: La leptospirosis es una zoonosis emergente, endémica en Colombia, que afecta tanto ... more Introducción: La leptospirosis es una zoonosis emergente, endémica en Colombia, que afecta tanto animales domésticos como silvestres. Es considerada de riesgo laboral, ya que la transmisión al ser humano está asociada a la exposición con animales o ambientes infectados. En el departamento de Nariño, la producción de cuyes para el consumo humano se realiza en sistemas de crianza tradicionales que podrían favorecer la infección por Leptospira interrogans en esta especie. Objetivo: Detectar molecularmente la infección natural por especies patógenas del género Leptospira en cuyes que son destinados para el consumo humano en el municipio de Pasto. Materiales y métodos: Se tomaron 270 muestras de tejido renal en cuyes sacrificados en dos mataderos. Las muestras fueron analizadas mediante Reacción en Cadena de la Polimerasa (PCR) convencional y coloración diferencial de Warthin Starry (W-S). Resultados: En la evaluación de las 270 muestras, 4 (1,5%) fueron positivas para PCR y una de las m...

Microorganisms
Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the gen... more Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the genus Leptospira. This zoonotic disease affects humans, domestic animals and wild animals. Colombia is considered an endemic country for leptospirosis; Antioquia is the second department in Colombia, with the highest number of reported leptospirosis cases. Currently, many studies report bats as reservoirs of Leptospira spp. but the prevalence in these mammals is unknown. The goal of this study was to better understand the role of bats as reservoir hosts of Leptospira species and to evaluate the genetic diversity of circulating Leptospira species in Antioquia-Colombia. We captured 206 bats in the municipalities of Chigorodó (43 bats), Carepa (43 bats), Apartadó (39 bats), Turbo (40 bats), and Necoclí (41 bats) in the Urabá region (Antioquia-Colombia). Twenty bats tested positive for Leptospira spp. infection (20/206—9.70%) and the species of infected bats were Carollia perspicillata, Dermanu...

Microorganisms
Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the gen... more Leptospirosis is a globally distributed zoonotic disease caused by pathogenic bacteria of the genus Leptospira. This zoonotic disease affects humans, domestic animals and wild animals. Colombia is considered an endemic country for leptospirosis; Antioquia is the second department in Colombia, with the highest number of reported leptospirosis cases. Currently, many studies report bats as reservoirs of Leptospira spp. but the prevalence in these mammals is unknown. The goal of this study was to better understand the role of bats as reservoir hosts of Leptospira species and to evaluate the genetic diversity of circulating Leptospira species in Antioquia-Colombia. We captured 206 bats in the municipalities of Chigorodó (43 bats), Carepa (43 bats), Apartadó (39 bats), Turbo (40 bats), and Necoclí (41 bats) in the Urabá region (Antioquia-Colombia). Twenty bats tested positive for Leptospira spp. infection (20/206—9.70%) and the species of infected bats were Carollia perspicillata, Dermanu...
Journal of Clinical Immunology
Due to typesetting mistake, the caption of Figure was mistakenly replaced with the caption of Fig... more Due to typesetting mistake, the caption of Figure was mistakenly replaced with the caption of Figure . The original version has been corrected.

Journal of Clinical Immunology
The noncanonical NF-κB pathway is implicated in diverse biological and immunological processes. M... more The noncanonical NF-κB pathway is implicated in diverse biological and immunological processes. Monoallelic C-terminus loss-of-function and gain-of-function mutations of NFKB2 have been recently identified as a cause of immunodeficiency manifesting with common variable immunodeficiency (CVID) or combined immunodeficiency (CID) phenotypes. Herein we report a family carrying a heterozygous nonsense mutation in NFKB2 (c.809G > A, p.W270*). This variant is associated with increased mRNA decay and no mutant NFKB2 protein expression, leading to NFKB2 haploinsufficiency. Our findings demonstrate that bona fide NFKB2 haploinsufficiency, likely caused by mutant mRNA decay and protein instability leading to the transcription and expression of only the wild-type allele, is associated with clinical immunodeficiency, although with incomplete clinical penetrance. Abnormal B cell development, hypogammaglobulinemia, poor antibody response, and abnormal noncanonical (but normal canonical) NF-κB pathway signaling are the immunologic hallmarks of this disease. This adds a third allelic variant to the pathophysiology of NFKB2-mediated immunodeficiency disorders.
Revista da Sociedade Brasileira de Medicina Tropical
Introduction: Phylogenetic analysis of the 16S ribosomal gene initial region is used to identify ... more Introduction: Phylogenetic analysis of the 16S ribosomal gene initial region is used to identify Leptospira isolates at the species level from clinical samples. Unfortunately, this method cannot differentiate between some intermediates and saprophytic species. Methods: We used comparative genomic analysis between 35 Leptospira species to find new molecular targets for Leptospira species identification. Results: We proposed the use of the rpoC gene, encoding the DNA-directed RNA polymerase β-subunit, for identifying 35 Leptospira species. Conclusions: The rpoC gene can be a molecular target to identify the main species of the Leptospira genus directly from clinical samples.
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Volumen 25 Número 2 by ronald guillermo peláez sánchez
Papers by ronald guillermo peláez sánchez