Trypanosoma lambrechti n. sp. aislado de micos (cebus albifrons) de colombia

En un estudio en sangre de micos colombianos, pertenecientes a 13 especies diferentes, 3 de 12 Cebus albifrons hospedaban en su sangre periférica un número muy bajo de Trypanosoma lambrechti n. sp.  La longitud promedio del tripanosoma, incluyendo la porción libre del fIagelo, es 34.9 micrones (30.1 - 43.2 micrones). EI cinetoplasto submarginal es muy pequeño y se sitúa en la cercanía del núcleo. EI núcleo es pequeño, oval o en forma de banda y ocupa la mayor parte de la anchura del cuerpo. Existe una zona clara anterior del núcleo. La parte anterior del cuerpo se colorea más intensamente que la parte posterior.  EI tripanosoma no infecta al Rhodnius prolixus, pero se multiplica facilmente en medio difásico de agar-sangre. Se da una tabla de diferenciación entre el nuevo tripanosoma y el polimorfo T. conorrhini.En un estudio en sangre de micos colombianos, pertenecientes a 13 especies diferentes, 3 de 12 Cebus albifrons hospedaban en su sangre periférica un número muy bajo de Trypanosoma lambrechti n. sp.  La longitud promedio del tripanosoma, incluyendo la porción libre del fIagelo, es 34.9 micrones (30.1 - 43.2 micrones). EI cinetoplasto submarginal es muy pequeño y se sitúa en la cercanía del núcleo. EI núcleo es pequeño, oval o en forma de banda y ocupa la mayor parte de la anchura del cuerpo. Existe una zona clara anterior del núcleo. La parte anterior del cuerpo se colorea más intensamente que la parte posterior.  EI tripanosoma no infecta al Rhodnius prolixus, pero se multiplica facilmente en medio difásico de agar-sangre. Se da una tabla de diferenciación entre el nuevo tripanosoma y el polimorfo T. conorrhini

Cross-reactivity between Trypanosoma Rangeli and Trypanosoma Cruzi, and its possible protective role in chagasic infection in mice

Sobre la base de la gran similaridad antigénica entre T.rangeli y T. cruzi, que ha sido reportada por los diversos investigadores, el presente estudio muestra un fenómeno de protección en ratones de experimentación OF-1 frente a una infección chagásica, con previa inmunización de los animales con dos estadios de desarrollo de T. rangeli (tripomastigotes metacÍclicos y/o epimastigotes), por diferentes rutas corporales.Palabras clave: trypanosoma rangeli, trypanosoma cruzi, Trypanosomiasis Americana, Enfermedad de chagas.Based on the great antigenic similarity between T. rangeli and T. cruzi, which has been reported by various researchers, the present study shows a phenomenon of protection in OF-1 experimental mice against a chagasic infection, with previous immunization. of animals with two stages of development of T. rangeli (metacyclic trypomastigotes and/or epimastigotes), by different body routes. Keywords: trypanosoma rangeli, trypanosoma cruzi, American trypanosomiasis, Chagas disease.De saúde. Tudo isso levou à criação de novas políticas públicas que contribuem para o controle da disseminação dessas patologias (1), que atingem as comunidades sem discriminação de idade, sexo ou etnia. Por esta razão, é importante ter em conta o papel que o COVID-19 tem tido na nossa sociedade do ponto de vista pediátrico

Phylogenetic Analysis of Bolivian Bat Trypanosomes of the Subgenus Schizotrypanum Based on Cytochrome b Sequence and Minicircle Analyses

The aim of this study was to establish the phylogenetic relationships of trypanosomes present in blood samples of Bolivian Carollia bats. Eighteen cloned stocks were isolated from 115 bats belonging to Carollia perspicillata (Phyllostomidae) from three Amazonian areas of the Chapare Province of Bolivia and studied by xenodiagnosis using the vectors Rhodnius robustus and Triatoma infestans (Trypanosoma cruzi marenkellei) or haemoculture (Trypanosoma dionisii). The PCR DNA amplified was analyzed by nucleotide sequences of maxicircles encoding cytochrome b and by means of the molecular size of hyper variable regions of minicircles. Ten samples were classified as Trypanosoma cruzi marinkellei and 8 samples as Trypanosoma dionisii. The two species have a different molecular size profile with respect to the amplified regions of minicircles and also with respect to Trypanosoma cruzi and Trypanosoma rangeli used for comparative purpose. We conclude the presence of two species of bat trypanosomes in these samples, which can clearly be identified by the methods used in this study. The presence of these trypanosomes in Amazonian bats is discussed

Trypanosoma cruzi genome plasticity and evolution

Trypanosoma cruzi, a protozoan from the Kinetoplastidae family, is the etiologic agent of Chagas disease, a major public health problem affecting mostly the poorest areas of Latin America. Due to the complex nature of the parasite’s genome it has been impossible to produce a complete reference genome sequence, thus hampering the implementation of post- genomic approaches to unveil the mechanisms of generation of antigenic variation and the identification of new drug targets. My doctoral studies have focused on the application of combined genome sequencing and computational methods to produce a complete reference T. cruzi genome sequence and perform comparative analyses to better understand the mechanisms that allow T. cruzi to evade the mammalian host immune system and to briskly adapt to novel environments. In paper I and II, different genome assembly strategies and second generation sequencing technologies were implemented to perform comparative analyses to identify elements of virulence between T. cruzi and two trypanosomatids that are non-pathogenic to humans: Trypanosoma cruzi marinkellei, a bat-restricted sub-species of the T. cruzi clade and the human avirulent species Trypanosoma rangeli. The studies reveal the expansion of T. cruzi- specific genomic traits specialised in the invasion of mammalian cells. In paper III, using third-generation, PacBio sequencing data it was possible to assemble the complete reference genome sequence of a Trypanosoma cruzi isolate from the DTU-I clade. This breakthrough allowed us - for the first time - to explore in detail the genome architecture of the subtelomeric areas where many parasite virulence factors are encoded. One of the most interesting discoveries was the overrepresentation of interspersed retrotransposons and microsatellites in tandem gene arrays coding for surface molecules, hinting at a retrotransposon-driven mechanism of recombination for generating new sequence variants. Whole genome sequencing of 35 T. cruzi DTU-I isolates, collected from different locations in the American continent, made possible to identify and characterise the mechanisms of adaptability employed by the parasite. Finally, paper IV analyses the mechanisms of genomic hybridisation in T. cruzi and the evolution over time of the hybrid offspring. The analysis revealed that during hybrid formation, the parasite integrates genetic material from each parental strains with the aid of retrotransposons and microsatellites, and the genome of these hybrid isolates moves quickly from a tetraploid to a diploid state. As a result, the hybrid strain has more genetic material, mostly in the subtelomeres, providing the parasite with a pool of new surface molecule genes with the potential to possibly increase its fitness in a new environment. In conclusion, the work presented here has advanced the understanding of parasite biology and provided a genomic resource to be exploited for the identification of drug targets and vaccine candidates

Chagas Cardiomyopathy Manifestations and Trypanosoma cruzi Genotypes Circulating in Chronic Chagasic Patients

Chagas disease caused by Trypanosoma cruzi is a complex disease that is endemic and an important problem in public health in Latin America. The T. cruzi parasite is classified into six discrete taxonomic units (DTUs) based on the recently proposed nomenclature (TcI, TcII, TcIII, TcIV, TcV and TcVI). The discovery of genetic variability within TcI showed the presence of five genotypes (Ia, Ib, Ic, Id and Ie) related to the transmission cycle of Chagas disease. In Colombia, TcI is more prevalent but TcII has also been reported, as has mixed infection by both TcI and TcII in the same Chagasic patient. The objectives of this study were to determine the T. cruzi DTUs that are circulating in Colombian chronic Chagasic patients and to obtain more information about the molecular epidemiology of Chagas disease in Colombia. We also assessed the presence of electrocardiographic, radiologic and echocardiographic abnormalities with the purpose of correlating T. cruzi genetic variability and cardiac disease. Molecular characterization was performed in Colombian adult chronic Chagasic patients based on the intergenic region of the mini-exon gene, the 24Sα and 18S regions of rDNA and the variable region of satellite DNA, whereby the presence of T.cruzi I, II, III and IV was detected. In our population, mixed infections also occurred, with TcI-TcII, TcI-TcIII and TcI-TcIV, as well as the existence of the TcI genotypes showing the presence of genotypes Ia and Id. Patients infected with TcI demonstrated a higher prevalence of cardiac alterations than those infected with TcII. These results corroborate the predominance of TcI in Colombia and show the first report of TcIII and TcIV in Colombian Chagasic patients. Findings also indicate that Chagas cardiomyopathy manifestations are more correlated with TcI than with TcII in Colombia