Publications by authors named "Gustavo Vallejo"

Background: Immune response of triatomines plays an important role in the success or failure of transmission of T. cruzi. Studies on parasite-vector interaction have shown the presence of trypanolytic factors and have been observed to be differentially expressed among triatomines, which affects the transmission of some T.

View Article and Find Full Text PDF

Trypanosoma cruzi causes Chagas disease and has a unique extranuclear genome enclosed in a structure called the kinetoplast, which contains circular genomes known as maxi- and minicircles. While the structure and function of maxicircles are well-understood, many aspects of minicircles remain to be discovered. Here, we performed a high-throughput analysis of the minicirculome (mcDNA) in 50 clones isolated from Colombia's diverse T.

View Article and Find Full Text PDF

Trypanosomatids, including Trypanosoma and Leishmania species, present significant medical and veterinary challenges, causing substantial economic losses, health complications, and even fatalities. Diagnosing and genotyping these species and their genotypes is often complex, involving multiple steps. This study aimed to develop an amplicon-based sequencing (ABS) method using Oxford Nanopore long-read sequencing to enhance Trypanosomatid detection and genotyping.

View Article and Find Full Text PDF

Chagas is an endemic disease in tropical regions of Latin America, caused by the parasite Trypanosoma cruzi. High intraspecies variability and genome complexity have been challenges to assemble high quality genomes needed for studies in evolution, population genomics, diagnosis and drug development. Here we present a chromosome-level phased assembly of a TcI T.

View Article and Find Full Text PDF

Introduction: Aedes albopictus is a vector for arboviruses, such as dengue, Zika, chikungunya, and yellow fever. The first A. albopictus reports on the American continent date back to 1985.

View Article and Find Full Text PDF

, the causal agent of Chagas disease, is mainly transmitted by insects of the Triatominae subfamily. In Colombia, there are 26 triatomine species, and 16 of them are naturally infected with the parasite. The parasite loads of naturally infected vectors can be significant in targeting specific species that can affect the epidemiology of the disease.

View Article and Find Full Text PDF

the causative agent of Chagas disease shows a marked genetic diversity and divided into at least six Discrete Typing Units (DTUs). High intra genetic variability has been observed in the TcI DTU, the most widely distributed DTU, where patterns of genomic diversity can provide information on ecological and evolutionary processes driving parasite population structure and genome organization. Chromosomal aneuploidies and rearrangements across multigene families represent an evidence of genome plasticity.

View Article and Find Full Text PDF

Introduction: Toxoplasma gondii is a parasite with great zoonotic potential. It can infect a broad range of warm-blooded hosts (including livestock) and causes significant losses in the industry. In humans, it has been described as a pathogen in immunosuppressed people, it affects the fetus development in congenital infections, and is associated with various behavioral disorders in healthy people.

View Article and Find Full Text PDF

We sequenced maxicircles from T. cruzi strains representative of the species evolutionary diversity by using long-read sequencing, which allowed us to uncollapse their repetitive regions, finding that their real lengths range from 35 to 50 kb. T.

View Article and Find Full Text PDF

Panstrongylus geniculatus (Latreille, 1811) is the triatomine with the largest geographic distribution in Latin America. It has been reported in 18 countries from southern Mexico to northern Argentina, including the Caribbean islands. Although most reports indicate that P.

View Article and Find Full Text PDF

Metacyclogenesis is one of the most important processes in the life cycle of . In this stage, noninfective epimastigotes become infective metacyclic trypomastigotes. However, the transcriptomic changes that occur during this transformation remain uncertain.

View Article and Find Full Text PDF

Introduction: Rhodnius (Hemiptera: Reduviidae: Triatominae) species are made up of haematophagous insect vectors for Trypanosoma cruzi (Chagas’ disease aetiological agent) and T. rangeli, an infective parasite that is not pathogenic for vertebrate hosts. The study of their salivary protein diversity enables the obtention of characteristic one-dimensional electrophoretic profiles of some triatomine species; however, few reports have dealt with Rhodnius species salivary proteins electrophoretic patterns.

View Article and Find Full Text PDF

is a flagellated protozoan that causes Chagas disease; it presents a complex life cycle comprising four morphological stages: epimastigote (EP), metacyclic trypomastigote (MT), cell-derived trypomastigote (CDT) and amastigote (AM). Previous transcriptomic studies on three stages (EPs, CDTs and AMs) have demonstrated differences in gene expressions among them; however, to the best of our knowledge, no studies have reported on gene expressions in MTs. Therefore, the present study compared differentially expressed genes (DEGs), and signaling pathway reconstruction in EPs, MTs, AMs and CDTs.

View Article and Find Full Text PDF

Background: Severe changes in temperature can affect the behavior and ecology of some infectious agents. Trypanosoma cruzi is a protozoan that causes Chagas disease. This parasite has high genetic variability and can be divided into six discrete typing units (DTUs).

View Article and Find Full Text PDF

spp. has become one of the protozoans arousing the greatest scientific interest because of the controversy surrounding its biology; it is currently considered one of the most prevalent organisms in humans and animals worldwide. Such prevalence increases, especially in tropical countries where infection rates are high, highlighting the need to conduct studies focused on understanding this protozoan's biology.

View Article and Find Full Text PDF
Article Synopsis
  • * This study focuses on the genetic diversity and patterns of the P. geniculatus species in Colombia and Venezuela, using mitochondrial and nuclear data to identify different clades and their geographic distribution.
  • * The findings reveal P. geniculatus as a monophyletic species divided into four geographic clades, suggesting a need for further research on environmental and human effects impacting these populations to improve Chagas disease control strategies.
View Article and Find Full Text PDF

From the 1930s until the end of the Second World War, Count Keyserling's statement that "the hour of eugenics is at hand" was used to champion ideas and practices that Nancy Stepan argues were shared by different Latin American countries. We focus on the period prior to that, a sort of zero hour of eugenics in Argentina, which began institutionalizing in 1910 and emerged as a new scientific field. This period was marked by intra- and interdisciplinary tensions, a struggle to monopolize scientific authority, and dialogues between ideology and power in which a viscous type of eugenics was inscribed, whose initial polyphony lasted until 1932.

View Article and Find Full Text PDF

The increase in the global land temperature, expected under predictions of climate change, can directly affect the transmission of some infectious diseases, including Chagas disease, an anthropozoonosis caused by Trypanosoma cruzi and transmitted by arthropod vectors of the subfamily Triatominae. This work seeks to study the effects of temperature on the development of the life cycle, fertility and fecundity of the insect vector Rhodnius prolixus and on the metacyclogenesis of T. cruzi.

View Article and Find Full Text PDF

Introduction: Trypanosoma cruzi has been divided by international consensus into six discrete typing units (DTU): TcI, TcII, TcIII, TcIV, TcV y TcVI. The factors determining the dynamics of T. cruzi genotypes vector transmission of Chagas' disease in the different geographical regions of Perú are still unknown.

View Article and Find Full Text PDF

Metacyclic trypomastigotes are essential for the understanding of the biology of Trypanosoma cruzi, the agent of Chagas disease. However, obtaining these biological stages in axenic medium is difficult. Techniques based on charge and density of the parasite during different stages have been implemented, without showing a high efficiency in the purification of metacyclic trypomastigotes.

View Article and Find Full Text PDF

Many single-nucleotide polymorphisms (SNPs) in the non-recombining region of the human Y chromosome have been described in the last decade. High-coverage sequencing has helped to characterize new SNPs, which has in turn increased the level of detail in paternal phylogenies. However, these paternal lineages still provide insufficient information on population history and demography, especially for Native Americans.

View Article and Find Full Text PDF

Trypanosoma rangeli is a nonpathogenic parasite for humans; however, its medical importance relies in its similarity and overlapping distribution with Trypanosoma cruzi, causal agent of Chagas disease in the Americas. The genetic diversity of T. rangeli and its association with host species (triatomines and mammals) has been identified along Central and the South America; however, it has not included data of isolates from Ecuador.

View Article and Find Full Text PDF