WorldWideScience

Sample records for acute trypanosoma cruzi

  1. Trypanosoma cruzi: circulating antigens

    V. Bongertz

    1981-03-01

    Full Text Available Circulating antigens were detected in sera of mice experimentally infected with a high close of Trypanosoma cruzi by reaction with sera from chronically infected mice. The immunodiffusion reaction between homologous acute and chronic sera produced four precipitation lines. By reaction with chronic mouse serum, circulating antingens were detected in sera from heavily infected hamsters, dogs, rabbits and in sera from chagasic patients. A reaction was also found in urine from acutely infected mice and dogs. Trypanosoma cruzi exoantigen was detected in trypanosome culture medium and in the supernatant of infected cell cultures. Attempts to isolate the antigens are described.Antígenos circulantes foram detectados em soros de camundongos infectados experimentalmente com elevadas doses de Trypanosoma cruzi pela reação com soros obtidos de camundongos em fase crônica de infecção. A reação de imunodifusão entre soros homólogos agudo e crônico produziu quatro linhas de precipitação. Por reação com soro crônico de camundongo antígenos circulantes foram detectados em soros de crícetos, cães e coelhos infectados com doses elevadas de Trypanosoma cruzi e em soros de pacientes chagásicos. Uma reação foi também observada com urina de camundongos e cães infectados de forma aguda. Exoantígeno de Trypanosoma cruzi foi detectado em meio de cultura de tripanosomas e em sobrenadantes de culturas de células infectadas. Tentativas de isolamento dos antigenos são descritas.

  2. Oral exposure to Phytomonas serpens attenuates thrombocytopenia and leukopenia during acute infection with Trypanosoma cruzi.

    da Silva, Rosiane V; Malvezi, Aparecida D; Augusto, Leonardo da Silva; Kian, Danielle; Tatakihara, Vera Lúcia H; Yamauchi, Lucy M; Yamada-Ogatta, Sueli F; Rizzo, Luiz V; Schenkman, Sergio; Pinge-Filho, Phileno

    2013-01-01

    Mice infected with Trypanosoma cruzi, the agent of Chagas disease, rapidly develop anemia and thrombocytopenia. These effects are partially promoted by the parasite trans-sialidase (TS), which is shed in the blood and depletes sialic acid from the platelets, inducing accelerated platelet clearance and causing thrombocytopenia during the acute phase of disease. Here, we demonstrate that oral immunization of C57BL/6 mice with Phytomonas serpens, a phytoflagellate parasite that shares common antigens with T. cruzi but has no TS activity, reduces parasite burden and prevents thrombocytopenia and leukopenia. Immunization also reduces platelet loss after intraperitoneal injection of TS. In addition, passive transfer of immune sera raised in mice against P. serpens prevented platelet clearance. Thus, oral exposure to P. serpens attenuates the progression of thrombocytopenia induced by TS from T. cruzi. These findings are not only important for the understanding of the pathogenesis of T. cruzi infection but also for developing novel approaches of intervention in Chagas disease. PMID:23844182

  3. Distantiae Transmission of Trypanosoma cruzi: A New Epidemiological Feature of Acute Chagas Disease in Brazil

    Xavier, Samanta Cristina das Chagas; Roque, André Luiz Rodrigues; Bilac, Daniele; de Araújo, Vitor Antônio Louzada; Neto, Sócrates Fraga da Costa; Lorosa, Elias Seixas; da Silva, Luiz Felipe Coutinho Ferreira; Jansen, Ana Maria

    2014-01-01

    Background The new epidemiological scenario of orally transmitted Chagas disease that has emerged in Brazil, and mainly in the Amazon region, needs to be addressed with a new and systematic focus. Belém, the capital of Pará state, reports the highest number of acute Chagas disease (ACD) cases associated with the consumption of açaí juice. Methodology/Principal Findings The wild and domestic enzootic transmission cycles of Trypanosoma cruzi were evaluated in the two locations (Jurunas and Val-...

  4. Distantiae transmission of Trypanosoma cruzi: a new epidemiological feature of acute Chagas disease in Brazil.

    Samanta Cristina das Chagas Xavier; André Luiz Rodrigues Roque; Daniele Bilac; Vitor Antônio Louzada de Araújo; Sócrates Fraga da Costa da Costa Neto; Elias Seixas Lorosa; Luiz Felipe Coutinho Ferreira da Silva; Ana Maria Jansen

    2014-01-01

    BACKGROUND: The new epidemiological scenario of orally transmitted Chagas disease that has emerged in Brazil, and mainly in the Amazon region, needs to be addressed with a new and systematic focus. Belém, the capital of Pará state, reports the highest number of acute Chagas disease (ACD) cases associated with the consumption of açaí juice. METHODOLOGY/PRINCIPAL FINDINGS: The wild and domestic enzootic transmission cycles of Trypanosoma cruzi were evaluated in the two locations (Jurunas and Va...

  5. Global metabolomic profiling of acute myocarditis caused by Trypanosoma cruzi infection.

    Núria Gironès

    2014-11-01

    Full Text Available Chagas disease is caused by Trypanosoma cruzi infection, being cardiomyopathy the more frequent manifestation. New chemotherapeutic drugs are needed but there are no good biomarkers for monitoring treatment efficacy. There is growing evidence linking immune response and metabolism in inflammatory processes and specifically in Chagas disease. Thus, some metabolites are able to enhance and/or inhibit the immune response. Metabolite levels found in the host during an ongoing infection could provide valuable information on the pathogenesis and/or identify deregulated metabolic pathway that can be potential candidates for treatment and being potential specific biomarkers of the disease. To gain more insight into those aspects in Chagas disease, we performed an unprecedented metabolomic analysis in heart and plasma of mice infected with T. cruzi. Many metabolic pathways were profoundly affected by T. cruzi infection, such as glucose uptake, sorbitol pathway, fatty acid and phospholipid synthesis that were increased in heart tissue but decreased in plasma. Tricarboxylic acid cycle was decreased in heart tissue and plasma whereas reactive oxygen species production and uric acid formation were also deeply increased in infected hearts suggesting a stressful condition in the heart. While specific metabolites allantoin, kynurenine and p-cresol sulfate, resulting from nucleotide, tryptophan and phenylalanine/tyrosine metabolism, respectively, were increased in heart tissue and also in plasma. These results provide new valuable information on the pathogenesis of acute Chagas disease, unravel several new metabolic pathways susceptible of clinical management and identify metabolites useful as potential specific biomarkers for monitoring treatment and clinical severity in patients.

  6. Extraction of Trypanosoma cruzi DNA from food: a contribution to the elucidation of acute Chagas disease outbreaks

    Renata Trotta Barroso Ferreira; Aline Martins Melandre; Maria Luiza Cabral; Maria Regina Branquinho; Paola Cardarelli-Leite

    2016-01-01

    Abstract: INTRODUCTION: Before 2004, the occurrence of acute Chagas disease (ACD) by oral transmission associated with food was scarcely known or investigated. Originally sporadic and circumstantial, ACD occurrences have now become frequent in the Amazon region, with recently related outbreaks spreading to several Brazilian states. These cases are associated with the consumption of açai juice by waste reservoir animals or insect vectors infected with Trypanosoma cruzi in endemic areas. Altho...

  7. Extraction of Trypanosoma cruzi DNA from food: a contribution to the elucidation of acute Chagas disease outbreaks

    Renata Trotta Barroso Ferreira

    2016-04-01

    Full Text Available Abstract: INTRODUCTION: Before 2004, the occurrence of acute Chagas disease (ACD by oral transmission associated with food was scarcely known or investigated. Originally sporadic and circumstantial, ACD occurrences have now become frequent in the Amazon region, with recently related outbreaks spreading to several Brazilian states. These cases are associated with the consumption of açai juice by waste reservoir animals or insect vectors infected with Trypanosoma cruzi in endemic areas. Although guidelines for processing the fruit to minimize contamination through microorganisms and parasites exist, açai-based products must be assessed for quality, for which the demand for appropriate methodologies must be met. METHODS: Dilutions ranging from 5 to 1,000 T. cruzi CL Brener cells were mixed with 2mL of acai juice. Four Extraction of T. cruzi DNA methods were used on the fruit, and the cetyltrimethyl ammonium bromide (CTAB method was selected according to JRC, 2005. RESULTS: DNA extraction by the CTAB method yielded satisfactory results with regard to purity and concentration for use in PCR. Overall, the methods employed proved that not only extraction efficiency but also high sensitivity in amplification was important. CONCLUSIONS: The method for T. cruzi detection in food is a powerful tool in the epidemiological investigation of outbreaks as it turns epidemiological evidence into supporting data that serve to confirm T. cruzi infection in the foods. It also facilitates food quality control and assessment of good manufacturing practices involving acai-based products.

  8. Use of Noninvasive Parameters to Evaluate Swiss Webster Mice During Trypanosoma cruzi Experimental Acute Infection.

    Campos, Jerônimo D S; Hoppe, Luanda Y; Duque, Thabata L A; de Castro, Solange Lisboa; Oliveira, Gabriel M

    2016-04-01

    Until now, there has been neither an agreed-upon experimental model nor descriptors of the clinical symptoms that occur over the course of acute murine infection. The aim of this work is to use noninvasive methods to evaluate clinical signs in Swiss Webster mice that were experimentally infected with the Y strain of Trypanosoma cruzi during acute phase (Inf group). Infected mice showed evident clinical changes beginning in the second week of infection (wpi) when compared to the noninfected group (NI): (1) animals in hunched postures, closed eyes, lowered ears, peeling skin, increased piloerection, prostration, and social isolation; (2) significant decrease in body weight (Inf: 26.2 ± 2.6 g vs. NI: 34.2 ± 2.5 g) and in chow (1.5 ± 0.3 vs. 6.3 ± 0.5 mg) and water (2.4 ± 0.5 vs. 5.8 ± 0.7 ml) intake; (3) significant decrease of spontaneous activity as locomotor parameters: distance (0.64 ± 0.06 vs. 1.8 ± 0.13 m), velocity (1.9 ± 0.3 vs. 6.7 ± 1.5 cm/sec), and exploratory behavior by frequency (1.0 ± 0.5 vs. 5.7 ± 1.0 events) and duration (1.4 ± 0.3 vs. 5.1 ± 0.5 sec in central arena region); (4) significant increase in the PR (41.7 ± 8.7 vs. 27.6 ± 1.9 msec) and QT intervals (39.7 ± 2.0 vs. 27.5 ± 4.0 msec), and a decreased cardiac frequency (505 ± 52.8 vs. 774 ± 17.8 msec), showing a marked sinus bradycardia and an atrioventricular block. At 3 and 4 wpi, the surviving animals showed a tendency of recovery in body weight, food intake, locomotor activity, and exploratory interest. Through the use of noninvasive parameters, we were able to monitor the severity of the infection in individuals prior to death. Our perspective is the application of noninvasive methods to describe clinical signs over the course of acute infection complementing the preclinical evaluation of new agents, alone or in combination with benznidazole. PMID:26741817

  9. Evasion of the immune response by Trypanosoma cruzi during acute infection

    Mariana Santos Cardoso

    2016-01-01

    Full Text Available Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical disease that affects millions of people mainly in Latin America. To establish a life-long infection, T. cruzi must subvert the vertebrate host’s immune system, using strategies that can be traced to the parasite’s life cycle. Once inside the vertebrate host, metacyclic trypomastigotes rapidly invade a wide variety of nucleated host cells in a membrane-bound compartment known as the parasitophorous vacuole, which fuses to lysosomes, originating the phagolysosome. In this compartment, the parasite relies on a complex network of antioxidant enzymes to shield itself from lysosomal oxygen and nitrogen reactive species. Lysosomal acidification of the parasitophorous vacuole is an important factor that allows trypomastigote escape from the extremely oxidative environment of the phagolysosome to the cytoplasm, where it differentiates into amastigote forms. In the cytosol of infected macrophages, oxidative stress instead of being detrimental to the parasite, favors amastigote burden, which then differentiates into bloodstream trypomastigotes. Trypomastigotes released in the bloodstream upon the rupture of the host cell membrane express surface molecules, such as calreticulin and GP160 proteins, which disrupt initial and key components of the complement pathway, while others such as GPI-mucins stimulate immunoregulatory receptors, delaying the progression of a protective immune response. After an immunologically silent entry at the early phase of infection, T. cruzi elicits polyclonal B cell activation, hypergammaglobulinemia, and unspecific anti-T. cruzi antibodies, which are inefficient in controlling the infection. Additionally, the co-expression of several related but not identical epitopes derived from trypomastigote surface proteins delays the generation of T. cruzi-specific neutralizing antibodies. Later in the infection, the establishment of an anti-T. cruzi CD8

  10. Trypanosoma cruzi IV causing outbreaks of acute Chagas disease and infections by different haplotypes in the Western Brazilian Amazonia.

    Wuelton Marcelo Monteiro

    Full Text Available BACKGROUND: Chagas disease is an emergent tropical disease in the Brazilian Amazon Region, with an increasing number of cases in recent decades. In this region, the sylvatic cycle of Trypanosoma cruzi transmission, which constitutes a reservoir of parasites that might be associated with specific molecular, epidemiological and clinical traits, has been little explored. The objective of this work is to genetically characterize stocks of T. cruzi from human cases, triatomines and reservoir mammals in the State of Amazonas, in the Western Brazilian Amazon. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed 96 T. cruzi samples from four municipalities in distant locations of the State of Amazonas. Molecular characterization of isolated parasites from cultures in LIT medium or directly from vectors or whole human blood was performed by PCR of the non-transcribed spacer of the mini-exon and of the 24 S alfa ribosomal RNA gene, RFLP and sequencing of the mitochondrial cytochrome c oxidase subunit II (COII gene, and by sequencing of the glucose-phosphate isomerase gene. The T. cruzi parasites from two outbreaks of acute disease were all typed as TcIV. One of the outbreaks was triggered by several haplotypes of the same DTU. TcIV also occurred in isolated cases and in Rhodnius robustus. Incongruence between mitochondrial and nuclear phylogenies is likely to be indicative of historical genetic exchange events resulting in mitochondrial introgression between TcIII and TcIV DTUs from Western Brazilian Amazon. TcI predominated among triatomines and was the unique DTU infecting marsupials. CONCLUSION/SIGNIFICANCE: DTU TcIV, rarely associated with human Chagas disease in other areas of the Amazon basin, is the major strain responsible for the human infections in the Western Brazilian Amazon, occurring in outbreaks as single or mixed infections by different haplotypes.

  11. Curcumin Enhances the Anti-Trypanosoma cruzi Activity of Benznidazole-Based Chemotherapy in Acute Experimental Chagas Disease.

    Novaes, Rômulo Dias; Sartini, Marcus Vinicius Pessoa; Rodrigues, João Paulo Ferreira; Gonçalves, Reggiani Vilela; Santos, Eliziária Cardoso; Souza, Raquel Lopes Martins; Caldas, Ivo Santana

    2016-06-01

    Although curcumin can increase the effectiveness of drugs against malaria, combination therapies using the molecule have never been investigated in Chagas disease (ChD). Therefore, we evaluated the efficacy of curcumin as a complementary strategy to benznidazole (Bz)-based chemotherapy in mice acutely infected with Trypanosoma cruzi Eighty-four 12-week-old Swiss mice were equally randomized into seven groups: uninfected (NI), T. cruzi infected and untreated (INF), infected and treated with 100 mg/kg of body weight Bz (B100), 50 mg/kg Bz (B50), 100 mg/kg curcumin (C100), 100 mg/kg Bz plus 100 mg/kg curcumin (B100 plus C100), and 50 mg/kg Bz plus 100 mg/kg curcumin (B50 plus C100). After microscopic identification of blood trypomastigotes (4 days after inoculation), both drugs were administered by gavage once a day for 20 days. Curcumin showed limited antiparasitic, anti-inflammatory, and antioxidant effects when administered alone. When curcumin and Bz were combined, there was a drastic reduction in parasitemia, parasite load, mortality, anti-T. cruzi IgG reactivity, circulating levels of cytokines (gamma interferon [IFN-γ], interleukin 4 [IL-4], and MIP1-α), myocardial inflammation, and morphological and oxidative cardiac injury; these results exceeded the isolated effects of Bz. The combination of Bz and curcumin was also effective at mitigating liver toxicity triggered by Bz, increasing the parasitological cure rate, and preventing infection recrudescence in noncured animals, even when the animals were treated with 50% of the recommended therapeutic dose of Bz. By limiting the toxic effects of Bz and enhancing its antiparasitic efficiency, the combination of the drug with curcumin may be a relevant therapeutic strategy that is possibly better tolerated in ChD treatment than Bz-based monotherapy. PMID:27001816

  12. Early Diagnosis of Congenital Trypanosoma cruzi Infection, Using Shed Acute Phase Antigen, in Ushuaia, Tierra del Fuego, Argentina

    Mallimaci, María Cristina; Sosa-Estani, Sergio; Russomando, Graciela; Sanchez, Zunilda; Sijvarger, Carina; Alvarez, Isabel Marcela; Barrionuevo, Lola; Lopez, Carlos; Segura, Elsa Leonor

    2010-01-01

    Chagas' disease, or American trypanosomiasis, is caused by the protozoan parasite Trypanasoma cruzi. It is estimated that 15,000 new cases of congenital T. cruzi transmission occur in the Americas each year. The aim of this study was to estimate the rate of congenital T. cruzi infection in infants born to infected women living in Ushuaia, Argentina, as well to assess a serologic test using Shed Acute Phase Antigen (SAPA) for a timely diagnosis of congenital infection. The rate of congenital i...

  13. Immune Evasion Strategies of Trypanosoma cruzi

    Ana Flávia Nardy

    2015-01-01

    Full Text Available Microbes have evolved a diverse range of strategies to subvert the host immune system. The protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease, provides a good example of such adaptations. This parasite targets a broad spectrum of host tissues including both peripheral and central lymphoid tissues. Rapid colonization of the host gives rise to a systemic acute response which the parasite must overcome. The parasite in fact undermines both innate and adaptive immunity. It interferes with the antigen presenting function of dendritic cells via an action on host sialic acid-binding Ig-like lectin receptors. These receptors also induce suppression of CD4+ T cells responses, and we presented evidence that the sialylation of parasite-derived mucins is required for the inhibitory effects on CD4 T cells. In this review we highlight the major mechanisms used by Trypanosoma cruzi to overcome host immunity and discuss the role of parasite colonization of the central thymic lymphoid tissue in chronic disease.

  14. Immune Response to Trypanosoma cruzi Shed Acute Phase Antigen in Children from an Endemic Area for Chagas' Disease in Bolivia

    Simone Frédérique Brenière

    1997-07-01

    Full Text Available A field study of the immune response to the shed acute phase antigen (SAPA of Trypanosoma cruzi was carried out in the locality of Mizque, Cochabamba department, Bolivia. Schoolchildren (266, with an average of 8.6 ± 3.6 years, were surveyed for parasitological and serological diagnosis, as well as antibodies directed against SAPA using the corresponding recombinant protein in ELISA. The antibodies against SAPA were shown in 82% of patients presenting positive serological diagnosis (IgG specific antibodies. The positive and negative predictive values were 0.88. Antibodies anti-SAPA were shown in 80.8% of the chagasic patients in the initial stage of the infection (positive IgM serology and/or positive buffy coat (BC test and in 81.4% of the patients in the indeterminate stage of the infection (positive IgG serology with negative BC and IgM tests. These results show that the anti-SAPA response is not only present during the initial stage of the infection (few months but extends some years after infection

  15. The cell surface of Trypanosoma cruzi

    Wanderley de Souza

    1984-01-01

    Full Text Available The cell surface of trypanosomatids is formed by the plasma membrane and a layer of sub-pellicular microtubules which are connected to the plasma membrane. The plasma membrane is composed by proteins, lipids and carbohydrates which form the glycocalix. In this paper we will review briefly aspects related to the organization of the cell surface of Trypanosoma cruzi.

  16. The cell surface of Trypanosoma cruzi

    Wanderley de Souza; Thais Souto-Padrón

    1984-01-01

    The cell surface of trypanosomatids is formed by the plasma membrane and a layer of sub-pellicular microtubules which are connected to the plasma membrane. The plasma membrane is composed by proteins, lipids and carbohydrates which form the glycocalix. In this paper we will review briefly aspects related to the organization of the cell surface of Trypanosoma cruzi.

  17. Early diagnosis of congenital Trypanosoma cruzi infection, using shed acute phase antigen, in Ushuaia, Tierra del Fuego, Argentina.

    Mallimaci, María Cristina; Sosa-Estani, Sergio; Russomando, Graciela; Sanchez, Zunilda; Sijvarger, Carina; Alvarez, Isabel Marcela; Barrionuevo, Lola; Lopez, Carlos; Segura, Elsa Leonor

    2010-01-01

    Chagas' disease, or American trypanosomiasis, is caused by the protozoan parasite Trypanasoma cruzi. It is estimated that 15,000 new cases of congenital T. cruzi transmission occur in the Americas each year. The aim of this study was to estimate the rate of congenital T. cruzi infection in infants born to infected women living in Ushuaia, Argentina, as well to assess a serologic test using Shed Acute Phase Antigen (SAPA) for a timely diagnosis of congenital infection. The rate of congenital infection among children in the study was 4.4% (3/68). Our results show that for infants younger than 30 days of age, matched blood samples from mother and infant were capable of identifying congenital transmission of infection using an enzyme-linked immunosorbent assay with SAPA. For infants older than 3 months, congenital infection could be ruled out using the same procedure. PMID:20064996

  18. Dogs infected with the blood trypomastigote form of Trypanosoma cruzi display an increase expression of cytokines and chemokines plus an intense cardiac parasitism during acute infection.

    de Souza, Sheler Martins; Vieira, Paula Melo de Abreu; Roatt, Bruno Mendes; Reis, Levi Eduardo Soares; da Silva Fonseca, Kátia; Nogueira, Nívia Carolina; Reis, Alexandre Barbosa; Tafuri, Washington Luiz; Carneiro, Cláudia Martins

    2014-03-01

    The recent increase in immigration of people from areas endemic for Chagas disease (Trypanosoma cruzi) to the United States and Europe has raised concerns about the transmission via blood transfusion and organ transplants in these countries. Infection by these pathways occurs through blood trypomastigotes (BT), and these forms of T. cruzi are completely distinct of metacyclic trypomastigotes (MT), released by triatomine vector, in relation to parasite-host interaction. Thus, research comparing infection with these different infective forms is important for explaining the potential impacts on the disease course. Here, we investigated tissue parasitism and relative mRNA expression of cytokines, chemokines, and chemokine receptors in the heart during acute infection by MT or BT forms in dogs. BT-infected dogs presented a higher cardiac parasitism, increased relative mRNA expression of pro-inflammatory and immunomodulatory cytokines and of the chemokines CCL3/MIP-1α, CCL5/RANTES, and the chemokine receptor CCR5 during the acute phase of infection, as compared to MT-infected dogs. These results suggest that infection with BT forms may lead to an increased immune response, as revealed by the cytokines ratio, but this kind of immune response was not able to control the cardiac parasitism. Infection with the MT form presented an increase in the relative mRNA expression of IL-12p40 as compared to that of IL-10 or TGF-β1. Correlation analysis showed increased relative mRNA expression of IFN-γ as well as IL-10, which may be an immunomodulatory response, as well as an increase in the correlation of CCL5/RANTES and its CCR5 receptor. Our findings revealed a difference between inoculum sources of T. cruzi, as vectorial or transfusional routes of T. cruzi infection may trigger distinct parasite-host interactions during the acute phase, which may influence immunopathological aspects of Chagas disease. PMID:24317279

  19. Differential expression of microRNAs in thymic epithelial cells from Trypanosoma cruzi acutely-infected mice: putative role in thymic atrophy.

    Leandra eLinhares-Lacerda

    2015-08-01

    Full Text Available A common feature seen in acute infections is a severe atrophy of the thymus. This occurs in the murine model of acute Chagas disease. Moreover, in thymuses from Trypanosoma cruzi acutely infected mice, thymocytes exhibit an increase in the density of fibronectin and laminin integrin-type receptors, with an increase in migratory response ex-vivo. Thymic epithelial cells (TEC play a major role in the intrathymic T cell differentiation. To date, the consequences of molecular changes promoted by parasite infection upon thymus have not been elucidated. Considering the importance of microRNA for gene expression regulation, 85 microRNAs were analyzed in TEC from T. cruzi acutely infected mice. The infection significantly modulated 29 miRNAs and modulation of 9 was also dependent whether TEC sorted out from the thymus exhibited cortical or medullary phenotype. In silico analysis revealed that these miRNAs may control target mRNAs known to be responsible for chemotaxis, cell adhesion and cell death. Considering that we sorted TEC in the initial phase of thymocyte loss, it is conceivable that changes in TEC miRNA expression profile are functionally related to thymic atrophy, providing new clues to better understanding the mechanisms of the thymic involution seen in experimental Chagas disease.

  20. Susceptibility of radiation chimeras to Trypanosoma cruzi

    Reciprocal bone marrow transfers were performed with C3H/HeJ mice, which are susceptible to infection with the Brazil strain of Trypanosoma cruzi, and resistant F1 (C3H/HeJ X C57BL/6J) mice. Mice reconstituted after lethal irradiation with syngeneic bone marrow displayed the resistance phenotype of the strain used, but neither C3H mice reconstituted with F1 bone marrow cells nor F1 mice reconstituted with C3H bone marrow cells survived challenge. Resistance to T. cruzi appears to be dependent upon factors associated both with host background and with bone marrow-derived cells

  1. Unveiling the Trypanosoma cruzi Nuclear Proteome.

    Agenor de Castro Moreira dos Santos Júnior

    Full Text Available Replication of Trypanosoma cruzi, the etiological agent of Chagas disease, displays peculiar features, such as absence of chromosome condensation and closed mitosis. Although previous proteome and subproteome analyses of T. cruzi have been carried out, the nuclear subproteome of this protozoan has not been described. Here, we report, for the first time to the best of our knowledge, the isolation and proteome analysis of T. cruzi nuclear fraction. For that, T. cruzi epimastigote cells were lysed and subjected to cell fractionation using two steps of sucrose density gradient centrifugation. The purity of the nuclear fraction was confirmed by phase contrast and fluorescence microscopy. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS allowed the identification of 864 proteins. Among those, 272 proteins were annotated as putative uncharacterized, and 275 had not been previously reported on global T. cruzi proteome analysis. Additionally, to support our enrichment method, bioinformatics analysis in DAVID was carried out. It grouped the nuclear proteins in 65 gene clusters, wherein the clusters with the highest enrichment scores harbor members with chromatin organization and DNA binding functions.

  2. Unveiling the Trypanosoma cruzi Nuclear Proteome.

    dos Santos Júnior, Agenor de Castro Moreira; Kalume, Dário Eluan; Camargo, Ricardo; Gómez-Mendoza, Diana Paola; Correa, José Raimundo; Charneau, Sébastien; de Sousa, Marcelo Valle; de Lima, Beatriz Dolabela; Ricart, Carlos André Ornelas

    2015-01-01

    Replication of Trypanosoma cruzi, the etiological agent of Chagas disease, displays peculiar features, such as absence of chromosome condensation and closed mitosis. Although previous proteome and subproteome analyses of T. cruzi have been carried out, the nuclear subproteome of this protozoan has not been described. Here, we report, for the first time to the best of our knowledge, the isolation and proteome analysis of T. cruzi nuclear fraction. For that, T. cruzi epimastigote cells were lysed and subjected to cell fractionation using two steps of sucrose density gradient centrifugation. The purity of the nuclear fraction was confirmed by phase contrast and fluorescence microscopy. Liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) allowed the identification of 864 proteins. Among those, 272 proteins were annotated as putative uncharacterized, and 275 had not been previously reported on global T. cruzi proteome analysis. Additionally, to support our enrichment method, bioinformatics analysis in DAVID was carried out. It grouped the nuclear proteins in 65 gene clusters, wherein the clusters with the highest enrichment scores harbor members with chromatin organization and DNA binding functions. PMID:26383644

  3. Chronic experimental infection by Trypanosoma cruzi in Cebus apella monkeys

    A. Riarte

    1995-12-01

    Full Text Available Twenty young male Cebus apella monkeys were infected with CAl Trypanosoma cruzi strain and reinfected with CA l or Tulahuen T.cruzi strains, with different doses and parasite source. Subpatent parasitemia was usually demonstrated in acute and chronic phases. Patent parasitemia was evident in one monkey in the acute phase and in four of them in the chronic phase after re-inoculations with high doses of CAl strain. Serological conversion was observed in all monkeys; titers were low, regardless of the methods used to investigate anti-T. cruzi specific antibodies. Higher titers were induced only when re-inoculations were perfomed with the virulent Tulahuén strain or high doses of CAl strain. Clinical electrocardiographic and ajmaline test evaluations did not reveal changes between infected and control monkeys. Histopathologically, cardiac lesions were always characterized by focal or multifocal mononuclear infiltrates and/or isolated fibrosis, as seen during the acute and chronic phases; neither amastigote nests nor active inflammation and fibrogenic processes characteristic of human acute and chronic myocarditis respectively, were observed. These morphological aspects more closely resemble those found in the "indeterminate phase" and contrast with the more diffuse and progressive pattern of the human chagasic myocarditis. All monkeys survived and no mortality was observed.

  4. The Trypanosoma cruzi protease cruzain mediates immune evasion.

    Patricia S Doyle

    2011-09-01

    Full Text Available Trypanosoma cruzi is the causative agent of Chagas' disease. Novel chemotherapy with the drug K11777 targets the major cysteine protease cruzain and disrupts amastigote intracellular development. Nevertheless, the biological role of the protease in infection and pathogenesis remains unclear as cruzain gene knockout failed due to genetic redundancy. A role for the T. cruzi cysteine protease cruzain in immune evasion was elucidated in a comparative study of parental wild type- and cruzain-deficient parasites. Wild type T. cruzi did not activate host macrophages during early infection (<60 min and no increase in ∼P iκB was detected. The signaling factor NF-κB P65 colocalized with cruzain on the cell surface of intracellular wild type parasites, and was proteolytically cleaved. No significant IL-12 expression occurred in macrophages infected with wild type T. cruzi and treated with LPS and BFA, confirming impairment of macrophage activation pathways. In contrast, cruzain-deficient parasites induced macrophage activation, detectable iκB phosphorylation, and nuclear NF-κB P65 localization. These parasites were unable to develop intracellularly and survive within macrophages. IL 12 expression levels in macrophages infected with cruzain-deficient T. cruzi were comparable to LPS activated controls. Thus cruzain hinders macrophage activation during the early (<60 min stages of infection, by interruption of the NF-κB P65 mediated signaling pathway. These early events allow T. cruzi survival and replication, and may lead to the spread of infection in acute Chagas' disease.

  5. Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains

    Maria Auxiliadora de Sousa

    1983-01-01

    Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones.Tripomastigotas sanguíneos de algumas cepas de Trypanosoma cruzi foram processadas em colunas de DEAE-celulose s...

  6. Shelter Dogs as Sentinels for Trypanosoma cruzi Transmission across Texas

    Tenney, Trevor D.; Curtis-Robles, Rachel; SNOWDEN, KAREN F.; Hamer, Sarah A.

    2014-01-01

    Chagas disease, an infection with the parasite Trypanosoma cruzi, is increasingly diagnosed among humans in the southern United States. We assessed exposure of shelter dogs in Texas to T. cruzi; seroprevalence across diverse ecoregions was 8.8%. Canine serosurveillance is a useful tool for public health risk assessment.

  7. Shelter dogs as sentinels for Trypanosoma cruzi transmission across Texas.

    Tenney, Trevor D; Curtis-Robles, Rachel; Snowden, Karen F; Hamer, Sarah A

    2014-08-01

    Chagas disease, an infection with the parasite Trypanosoma cruzi, is increasingly diagnosed among humans in the southern United States. We assessed exposure of shelter dogs in Texas to T. cruzi; seroprevalence across diverse ecoregions was 8.8%. Canine serosurveillance is a useful tool for public health risk assessment. PMID:25062281

  8. Differential gene expression during Trypanosoma cruzi metacyclogenesis

    Marco Aurelio Krieger

    1999-09-01

    Full Text Available The transformation of epimastigotes into metacyclic trypomastigotes involves changes in the pattern of expressed genes, resulting in important morphological and functional differences between these developmental forms of Trypanosoma cruzi. In order to identify and characterize genes involved in triggering the metacyclogenesis process and in conferring to metacyclic trypomastigotes their stage specific biological properties, we have developed a method allowing the isolation of genes specifically expressed when comparing two close related cell populations (representation of differential expression or RDE. The method is based on the PCR amplification of gene sequences selected by hybridizing and subtracting the populations in such a way that after some cycles of hybridization-amplification genes specific to a given population are highly enriched. The use of this method in the analysis of differential gene expression during T. cruzi metacyclogenesis (6 hr and 24 hr of differentiation and metacyclic trypomastigotes resulted in the isolation of several clones from each time point. Northern blot analysis showed that some genes are transiently expressed (6 hr and 24 hr differentiating cells, while others are present in differentiating cells and in metacyclic trypomastigotes. Nucleotide sequencing of six clones characterized so far showed that they do not display any homology to gene sequences available in the GeneBank.

  9. Flagellar Motility of Trypanosoma cruzi Epimastigotes

    G. Ballesteros-Rodea

    2012-01-01

    Full Text Available The hemoflagellate Trypanosoma cruzi is the causative agent of American trypanosomiasis. Despite the importance of motility in the parasite life cycle, little is known about T. cruzi motility, and there is no quantitative description of its flagellar beating. Using video microscopy and quantitative vectorial analysis of epimastigote trajectories, we find a forward parasite motility defined by tip-to-base symmetrical flagellar beats. This motion is occasionally interrupted by base-to-tip highly asymmetric beats, which represent the ciliary beat of trypanosomatid flagella. The switch between flagellar and ciliary beating facilitates the parasite's reorientation, which produces a large variability of movement and trajectories that results in different distance ranges traveled by the cells. An analysis of the distance, speed, and rotational angle indicates that epimastigote movement is not completely random, and the phenomenon is highly dependent on the parasite behavior and is characterized by directed and tumbling parasite motion as well as their combination, resulting in the alternation of rectilinear and intricate motility paths.

  10. Desaturation of fatty acids in Trypanosoma cruzi

    Uptake and metabolism of saturated (16:0, 18:0) and unsaturated [18:1(n-9), 18:2(n-6), 18:3(n-3)] fatty acids by cultured epimastigotes of Trypanosoma cruzi were studied. Between 17.5 and 33.5% of the total radioactivity of [1-14C]labeled fatty acids initially added to the culture medium was incorporated into the lipids of T. cruzi and mostly choline and ethanolamine phospholipids. As demonstrated by argentation thin layer chromatography, gas liquid chromatography and ozonolysis of the fatty acids synthesized, exogenous palmitic acid was elongated to stearic acid, and the latter was desaturated to oleic acid and 18:2 fatty acid. The 18:2 fatty acid was tentatively identified as linoleic acid with the first bond in the delta 9 position and the second bond toward the terminal methyl end. Exogenous stearic acid was also desaturated to oleic and 18:2 fatty acid, while oleic acid was only converted into 18:2. All of the saturated and unsaturated fatty acids investigated were also converted to a small extent (2-4%) into polyunsaturated fatty acids. No radioactive aldehyde methyl ester fragments of less than nine carbon atoms were detected after ozonolysis of any of the fatty acids studied. These results demonstrate the existence of delta 9 and either delta 12 or delta 15 desaturases, or both, in T. cruzi and suggest that delta 6 desaturase or other desaturases of the animal type are likely absent in cultured forms of this organism

  11. Synthesis and Anti-Trypanosoma cruzi Activity of Diaryldiazepines

    Júlio César L. Menezes

    2014-12-01

    Full Text Available Chagas disease is a so-called “neglected disease” and endemic to Latin America. Nifurtimox and benznidazole are drugs that have considerable efficacy in the treatment of the acute phase of the disease but cause many significant side effects. Furthermore, in the Chronic Phase its efficiency is reduced and their therapeutic effectiveness is dependent on the type of T. cruzi strain. For this reason, the present work aims to drive basic research towards the discovery of new chemical entities to treat Chagas disease. Differently substituted 5,7-diaryl-2,3-dihydro-1,4-diazepines were synthesized by cyclocondensation of substituted flavones with ethylenediamine and tested as anti-Trypanosoma cruzi candidates. Epimastigotes of the Y strain from T. cruzi were used in this study and the number of parasites was determined in a Neubauer chamber. The most potent diaryldiazepine that reduced epimastigote proliferation exhibited an IC50 value of 0.25 μM, which is significantly more active than benznidazole.

  12. [Digestive tract dilation in mice infected with Trypanosoma cruzi].

    Guillén-Pernía, B; Lugo-Yarbuh, A; Moreno, E

    2001-09-01

    This paper will analyze alterations in the digestive tract (DT) of mice with chronic Chagas' disease infection produced by Trypanosoma cruzi from different sources. X-rays of the DT of 18 mice infected with T. cruzi and 6 control mice were compared after the ingestion of a barium sulfate solution over a period of 6 hours. 120 days post-infection (pi) the X-rays of the DT of the 5 mice of group 1A infected with trypanosomes DMI isolated from the opossum Didelphis marsupialis, and 4 mice in group 2A infected with the isolate EP taken from a patient with acute Chagas' disease, showed swelling of the stomach and the colon (C). 180 days pi, the X-rays of the DT of the 5 mice of group 1B infected with isolated DMI and the 4 mice in group 2B infected with isolate EP, showed an even greater swelling of the C. Histological examination of the DT of all infected mice showed extensive changes of the intestinal muscle layer, such as the diminution of the muscular and mucous layers and the loss of colonic folds and myoenteric plexus. These results suggest that T. cruzi populations caused severe alterations in the digestive system of the mice used in the experiment, and that the same alterations could occur in the digestive organs of humans, especially those living in areas where Chagas' disease is endemic, but where these abnormalities have not yet been reported. PMID:11552508

  13. Altered Cardiomyocyte Function and Trypanosoma cruzi Persistence in Chagas Disease.

    Cruz, Jader Santos; Santos-Miranda, Artur; Sales-Junior, Policarpo Ademar; Monti-Rocha, Renata; Campos, Paula Peixoto; Machado, Fabiana Simão; Roman-Campos, Danilo

    2016-05-01

    Chagas disease, caused by the triatominae Trypanosoma cruzi, is one of the leading causes of heart malfunctioning in Latin America. The cardiac phenotype is observed in 20-30% of infected people 10-40 years after their primary infection. The cardiac complications during Chagas disease range from cardiac arrhythmias to heart failure, with important involvement of the right ventricle. Interestingly, no studies have evaluated the electrical properties of right ventricle myocytes during Chagas disease and correlated them to parasite persistence. Taking advantage of a murine model of Chagas disease, we studied the histological and electrical properties of right ventricle in acute (30 days postinfection [dpi]) and chronic phases (90 dpi) of infected mice with the Colombian strain of T. cruzi and their correlation to parasite persistence. We observed an increase in collagen deposition and inflammatory infiltrate at both 30 and 90 dpi. Furthermore, using reverse transcriptase polymerase chain reaction, we detected parasites at 90 dpi in right and left ventricles. In addition, we observed action potential prolongation and reduced transient outward K(+) current and L-type Ca(2+) current at 30 and 90 dpi. Taking together, our results demonstrate that T. cruzi infection leads to important modifications in electrical properties associated with inflammatory infiltrate and parasite persistence in mice right ventricle, suggesting a causal role between inflammation, parasite persistence, and altered cardiomyocyte function in Chagas disease. Thus, arrhythmias observed in Chagas disease may be partially related to altered electrical function in right ventricle. PMID:26976879

  14. An in vitro iron superoxide dismutase inhibitor decreases the parasitemia levels of Trypanosoma cruzi in BALB/c mouse model during acute phase

    Francisco Olmo

    2015-12-01

    Full Text Available In order to identify new compounds to treat Chagas disease during the acute phase with higher activity and lower toxicity than the reference drug benznidazole (Bz, two hydroxyphthalazine derivative compounds were prepared and their trypanocidal effects against Trypanosoma cruzi were evaluated by light microscopy through the determination of IC50 values. Cytotoxicity was determined by flow cytometry assays against Vero cells. In vivo assays were performed in BALB/c mice, in which the parasitemia levels were quantified by fresh blood examination; the assignment of a cure was determined by reactivation of blood parasitemia levels after immunosuppression. The mechanism of action was elucidated at metabolic and ultra-structural levels, by 1H NMR and TEM studies. Finally, as these compounds are potentially capable of causing oxidative damage in the parasites, the study was completed, by assessing their activity as potential iron superoxide dismutase (Fe-SOD inhibitors. High-selectivity indices observed in vitro were the basis of promoting one of the tested compounds to in vivo assays. The tests on the murine model for the acute phase of Chagas disease showed better parasitemia inhibition values than those found for Bz. Compound 2 induced a remarkable decrease in the reactivation of parasitemia after immunosuppression. Compound 2 turned out to be a great inhibitor of Fe-SOD. The high antiparasitic activity and low toxicity together with the modest costs for the starting materials render this compound an appropriate molecule for the development of an affordable anti-Chagas agent.

  15. Trypanosoma cruzi screening in Texas blood donors, 2008-2012.

    Garcia, M N; Woc-Colburn, L; Rossmann, S N; Townsend, R L; Stramer, S L; Bravo, M; Kamel, H; Beddard, R; Townsend, M; Oldham, R; Bottazzi, M E; Hotez, P J; Murray, K O

    2016-04-01

    Chagas disease is an important emerging disease in Texas that results in cardiomyopathy in about 30% of those infected with the parasite Trypanosoma cruzi. Between the years 2008 and 2012, about 1/6500 blood donors were T. cruzi antibody-confirmed positive. We found older persons and minority populations, particularly Hispanic, at highest risk for screening positive for T. cruzi antibodies during routine blood donation. Zip code analysis determined that T. cruzi is associated with poverty. Chagas disease has a significant disease burden and is a cause of substantial economic losses in Texas. PMID:25170765

  16. Papel do óxido nítrico no desenvolvimento de lesões cardíacas na fase aguda da infecção experimental pelo Trypanosoma cruzi Role of nitric oxide in the development of cardiac lesions during the acute phase of experimental infection by Trypanosoma cruzi

    Cláudia Renata Bibiano Borges

    2009-04-01

    Full Text Available A doença de Chagas é causada pelo Trypanosoma cruzi e o coração é o órgão mais acometido. O óxido nítrico apresenta importante ação anti-Trypanosoma, porém, com pouca evidência de seu papel no mecanismo de lesão tecidual. O objetivo deste estudo foi analisar a contribuição do óxido nítrico no desenvolvimento da inflamação e da fibrose cardíaca na fase aguda da infecção experimental por cepas Y e Colombiana do Trypanosoma cruzi. A inflamação foi significativamente maior nos animais infectados pela cepa Colombiana, comparada com os infectados com a cepa Y, tanto nos animais C57BL/6 (3,98x1,87%; p=0,004 quanto nos animais C57BL/6 deficientes na sintase do óxido nítrico induzível (3,99x2,4%; p=0,013. O parasitismo cardíaco dos animais C57BL/6 deficientes na sintase do óxido nítrico induzível infectados pela cepa Colombiana foi significativamente maior que o destes mesmos animais infectados com a cepa Y (2,78x0,17 ninhos/mm²; p=0,004 assim como, os animais C57BL/6 infectados com a cepa Colombiana (2,78x1,33 ninhos/mm²; p=0,006 ou cepa Y (2,78x0,53 ninhos/mm²; p=0,005. Os dados reforçam o papel do óxido nítrico no controle do parasitismo e sugerem seu papel na proteção tecidual, controlando a inflamação e potencialmente diminuindo lesões cardíacas durante a fase aguda na doença de Chagas experimental.Chagas disease is caused by Trypanosoma cruzi and the heart is the organ most affected. Nitric oxide has notable anti-Trypanosoma action, but with little evidence regarding its role in the mechanism for tissue injury. The objective of this study was to analyze the contribution of nitric oxide towards the development of inflammation and cardiac fibrosis during the acute phase of experimental infection by Y and Colombian strains of Trypanosoma cruzi. The inflammation was significantly more intense in animals infected with the Colombian strain, compared with those infected with the Y strain, both in C57BL/6

  17. Protein 3-nitrotyrosine formation during Trypanosoma cruzi infection in mice

    M. Naviliat

    2005-12-01

    Full Text Available Nitric oxide (·NO is a diffusible messenger implicated in Trypanosoma cruzi resistance. Excess production of ·NO and oxidants leads to the generation of nitrogen dioxide (·NO2, a strong nitrating agent. Tyrosine nitration is a post-translational modification resulting from the addition of a nitro (-NO2 group to the ortho-position of tyrosine residues. Detection of protein 3-nitrotyrosine is regarded as a marker of nitro-oxidative stress and is observed in inflammatory processes. The formation and role of nitrating species in the control and myocardiopathy of T. cruzi infection remain to be studied. We investigated the levels of ·NO and protein 3-nitrotyrosine in the plasma of C3H and BALB/c mice and pharmacologically modulated their production during the acute phase of T. cruzi infection. We also looked for protein 3-nitrotyrosine in the hearts of infected animals. Our results demonstrated that C3H animals produced higher amounts of ·NO than BALB/c mice, but their generation of peroxynitrite was not proportionally enhanced and they had higher parasitemias. While N G-nitro-arginine methyl ester treatment abolished ·NO production and drastically augmented the parasitism, mercaptoethylguanidine and guanido-ethyl disulfide, at doses that moderately reduced the ·NO and 3-nitrotyrosine levels, paradoxically diminished the parasitemia in both strains. Nitrated proteins were also demonstrated in myocardial cells of infected mice. These data suggest that the control of T. cruzi infection depends not only on the capacity to produce ·NO, but also on its metabolic fate, including the generation of nitrating species that may constitute an important element in parasite resistance and collateral myocardial damage.

  18. Ancestral Genomes, Sex, and the Population Structure of Trypanosoma cruzi.

    2006-03-01

    Full Text Available Acquisition of detailed knowledge of the structure and evolution of Trypanosoma cruzi populations is essential for control of Chagas disease. We profiled 75 strains of the parasite with five nuclear microsatellite loci, 24Salpha RNA genes, and sequence polymorphisms in the mitochondrial cytochrome oxidase subunit II gene. We also used sequences available in GenBank for the mitochondrial genes cytochrome B and NADH dehydrogenase subunit 1. A multidimensional scaling plot (MDS based in microsatellite data divided the parasites into four clusters corresponding to T. cruzi I (MDS-cluster A, T. cruzi II (MDS-cluster C, a third group of T. cruzi strains (MDS-cluster B, and hybrid strains (MDS-cluster BH. The first two clusters matched respectively mitochondrial clades A and C, while the other two belonged to mitochondrial clade B. The 24Salpha rDNA and microsatellite profiling data were combined into multilocus genotypes that were analyzed by the haplotype reconstruction program PHASE. We identified 141 haplotypes that were clearly distributed into three haplogroups (X, Y, and Z. All strains belonging to T. cruzi I (MDS-cluster A were Z/Z, the T. cruzi II strains (MDS-cluster C were Y/Y, and those belonging to MDS-cluster B (unclassified T. cruzi had X/X haplogroup genotypes. The strains grouped in the MDS-cluster BH were X/Y, confirming their hybrid character. Based on these results we propose the following minimal scenario for T. cruzi evolution. In a distant past there were at a minimum three ancestral lineages that we may call, respectively, T. cruzi I, T. cruzi II, and T. cruzi III. At least two hybridization events involving T. cruzi II and T. cruzi III produced evolutionarily viable progeny. In both events, the mitochondrial recipient (as identified by the mitochondrial clade of the hybrid strains was T. cruzi II and the mitochondrial donor was T. cruzi III.

  19. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

    Lantos, Andrés B.; Carlevaro, Giannina; Araoz, Beatriz; Ruiz Diaz, Pablo; Camara, María de los Milagros; Buscaglia, Carlos A.; Bossi, Mariano; Yu, Hai; Chen, Xi; Bertozzi, Carolyn R.; Mucci, Juan; Campetella, Oscar

    2016-01-01

    Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sial...

  20. Genome size, karyotype polymorphism and chromosomal evolution in Trypanosoma cruzi.

    Renata T Souza

    Full Text Available BACKGROUND: The Trypanosoma cruzi genome was sequenced from a hybrid strain (CL Brener. However, high allelic variation and the repetitive nature of the genome have prevented the complete linear sequence of chromosomes being determined. Determining the full complement of chromosomes and establishing syntenic groups will be important in defining the structure of T. cruzi chromosomes. A large amount of information is now available for T. cruzi and Trypanosoma brucei, providing the opportunity to compare and describe the overall patterns of chromosomal evolution in these parasites. METHODOLOGY/PRINCIPAL FINDINGS: The genome sizes, repetitive DNA contents, and the numbers and sizes of chromosomes of nine strains of T. cruzi from four lineages (TcI, TcII, TcV and TcVI were determined. The genome of the TcI group was statistically smaller than other lineages, with the exception of the TcI isolate Tc1161 (José-IMT. Satellite DNA content was correlated with genome size for all isolates, but this was not accompanied by simultaneous amplification of retrotransposons. Regardless of chromosomal polymorphism, large syntenic groups are conserved among T. cruzi lineages. Duplicated chromosome-sized regions were identified and could be retained as paralogous loci, increasing the dosage of several genes. By comparing T. cruzi and T. brucei chromosomes, homologous chromosomal regions in T. brucei were identified. Chromosomes Tb9 and Tb11 of T. brucei share regions of syntenic homology with three and six T. cruzi chromosomal bands, respectively. CONCLUSIONS: Despite genome size variation and karyotype polymorphism, T. cruzi lineages exhibit conservation of chromosome structure. Several syntenic groups are conserved among all isolates analyzed in this study. The syntenic regions are larger than expected if rearrangements occur randomly, suggesting that they are conserved owing to positive selection. Mapping of the syntenic regions on T. cruzi chromosomal bands

  1. Trypanosoma cruzi: avirulence of the PF strain to Callithrix marmosets

    Humberto Menezes

    1981-06-01

    Full Text Available Callithrix jacchus geoffroy marmosets (HumBol. 1812 were injected once subcutaneously with 10.000 parasites/g body weight and followed for a period of six months. The PF strain of Trypanosoma cruzi was used. Follow-up was done through blood cultures, xenodiagnosis, serological tests, and ECG. A small number of normaI animais served as control.

  2. Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains.

    de Sousa, M A

    1983-01-01

    Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones. PMID:6443631

  3. Papel do óxido nítrico no desenvolvimento de lesões cardíacas na fase aguda da infecção experimental pelo Trypanosoma cruzi Role of nitric oxide in the development of cardiac lesions during the acute phase of experimental infection by Trypanosoma cruzi

    Cláudia Renata Bibiano Borges; Virmondes Rodrigues Junior; Marlene Antônia dos Reis; Lúcio Roberto Castellano; Javier Emilio Lazo Chica; Sanívia Aparecida de Lima Pereira; Edjane Souza Santos; Denise Bertulucci Rocha Rodrigues

    2009-01-01

    A doença de Chagas é causada pelo Trypanosoma cruzi e o coração é o órgão mais acometido. O óxido nítrico apresenta importante ação anti-Trypanosoma, porém, com pouca evidência de seu papel no mecanismo de lesão tecidual. O objetivo deste estudo foi analisar a contribuição do óxido nítrico no desenvolvimento da inflamação e da fibrose cardíaca na fase aguda da infecção experimental por cepas Y e Colombiana do Trypanosoma cruzi. A inflamação foi significativamente maior nos animais infectados ...

  4. Immunobiochemical significance of Trypanosoma rangeli in the study of Trypanosoma cruzi

    Saldaña, Azael Patiño

    1997-01-01

    Trypanosoma rangeli is a haemoflagellate that infects humans nonpathogenicallyin some areas in which T. cruzi, the causative agent of Chagas' disease, is endemic.Since common biological and immunochemical characteristics have been described forthese parasites, a detailed study of their relationship is needed. In the presentwork, experimental murine infections demonstrated that T cruzi induces antibodiesthat recognize several T. rangeli antigenic polypeptides. In the same man...

  5. Protective immunity against Trypanosoma cruzi provided by oral immunization with Phytomonas serpens: role of nitric oxide.

    Pinge-Filho, P; Peron, J P S; de Moura, T R; Menolli, R A; Graça, V K; Estevão, D; Tadokoro, C E; Jankevicius, J V; Rizzo, L V

    2005-01-31

    We have previously demonstrated that Phytomonas serpens, a tomato parasite, shares antigens with Trypanosoma cruzi, the protozoa that causes Chagas' disease. These antigens are recognized by human sera and induce protective immunity in Balb/c mice. In the present study, inducible nitric oxide synthase (iNOS) knockout (KO) mice and C57BL/6 mice treated with the nitric oxide inhibitor, aminoguanidine (AG, 50 mg kg(-1)) infected with T. cruzi, were used to demonstrate the role of nitric oxide (NO) to host protection against T. cruzi infection achieved by oral immunization with live P. serpens. A reduction in parasitaemia and an increase in survival were observed in C57BL/6 infected mice and previously immunized with P. serpens, when compared to non-immunized mice. iNOS (KO) mice immunized and C57BL/6 immunized and treated with AG presented parasitaemia and mortality rates comparable to those of infected and non-immunized mice. By itself, immunization with P. serpens did not induce inflammation in the myocardium, but C57BL/6 mice so immunized showed fewer amastigotes nests in the heart following an acute T. cruzi infection than those in non-immunized mice. These results suggest that protective immunity against T. cruzi infection induced by immunization with P. serpens is dependent upon enhanced NO production during the acute phase of T. cruzi infection. PMID:15585334

  6. Interactions between Trypanosoma cruzi Secreted Proteins and Host Cell Signaling Pathways

    Watanabe Costa, Renata; da Silveira, Jose F.; Bahia, Diana

    2016-01-01

    Chagas disease is one of the prevalent neglected tropical diseases, affecting at least 6–7 million individuals in Latin America. It is caused by the protozoan parasite Trypanosoma cruzi, which is transmitted to vertebrate hosts by blood-sucking insects. After infection, the parasite invades and multiplies in the myocardium, leading to acute myocarditis that kills around 5% of untreated individuals. T. cruzi secretes proteins that manipulate multiple host cell signaling pathways to promote host cell invasion. The primary secreted lysosomal peptidase in T. cruzi is cruzipain, which has been shown to modulate the host immune response. Cruzipain hinders macrophage activation during the early stages of infection by interrupting the NF-kB P65 mediated signaling pathway. This allows the parasite to survive and replicate, and may contribute to the spread of infection in acute Chagas disease. Another secreted protein P21, which is expressed in all of the developmental stages of T. cruzi, has been shown to modulate host phagocytosis signaling pathways. The parasite also secretes soluble factors that exert effects on host extracellular matrix, such as proteolytic degradation of collagens. Finally, secreted phospholipase A from T. cruzi contributes to lipid modifications on host cells and concomitantly activates the PKC signaling pathway. Here, we present a brief review of the interaction between secreted proteins from T. cruzi and the host cells, emphasizing the manipulation of host signaling pathways during invasion. PMID:27065960

  7. Surface electrical charge of bloodstream trypomastigotes of Trypanosoma cruzi strains

    Maria Auxiliadora de Sousa

    1983-12-01

    Full Text Available Bloodstream trypomastigotes of some Trypanosoma cruzi strains were processed through DEAE-cellulose columns under standardized conditions. The results obtained suggest mainly that these strains present different surface charges, that there are subpopulations of bloodstream trypomastigotes as regards electrical charges and that the broad forms are less negative than the slender ones.Tripomastigotas sanguíneos de algumas cepas de Trypanosoma cruzi foram processadas em colunas de DEAE-celulose sob condições padronizadas. Os resultados obtidos sugerem principalmente que estas cepas possuem cargas superficiais diferentes, que em relação a este aspecto existem subpopulações de tripomastigotas e que as formas largas são menos negativas do que as finas.

  8. Trypanosoma cruzi: single cell live imaging inside infected tissues.

    Ferreira, Bianca Lima; Orikaza, Cristina Mary; Cordero, Esteban Mauricio; Mortara, Renato Arruda

    2016-06-01

    Although imaging the live Trypanosoma cruzi parasite is a routine technique in most laboratories, identification of the parasite in infected tissues and organs has been hindered by their intrinsic opaque nature. We describe a simple method for in vivo observation of live single-cell Trypanosoma cruzi parasites inside mammalian host tissues. BALB/c or C57BL/6 mice infected with DsRed-CL or GFP-G trypomastigotes had their organs removed and sectioned with surgical blades. Ex vivo organ sections were observed under confocal microscopy. For the first time, this procedure enabled imaging of individual amastigotes, intermediate forms and motile trypomastigotes within infected tissues of mammalian hosts. PMID:26639617

  9. Oxidative stress fuels Trypanosoma cruzi infection in mice

    Claudia N. Paiva; Feijó, Daniel F.; Dutra, Fabianno F.; Carneiro, Vitor C.; Freitas, Guilherme B.; Alves, Letícia S.; Mesquita, Jacilene; Fortes, Guilherme B.; Figueiredo, Rodrigo T.; de Souza, Heitor S P; Fantappié, Marcelo R.; Lannes-Vieira, Joseli; Bozza, Marcelo T.

    2012-01-01

    Oxidative damage contributes to microbe elimination during macrophage respiratory burst. Nuclear factor, erythroid-derived 2, like 2 (NRF2) orchestrates antioxidant defenses, including the expression of heme-oxygenase–1 (HO-1). Unexpectedly, the activation of NRF2 and HO-1 reduces infection by a number of pathogens, although the mechanism responsible for this effect is largely unknown. We studied Trypanosoma cruzi infection in mice in which NRF2/HO-1 was induced with cobalt protoporphyrin (Co...

  10. Mammalian cell sialic acid enhances invasion by Trypanosoma cruzi.

    Schenkman, R P; Vandekerckhove, F.; Schenkman, S

    1993-01-01

    We have used a Chinese hamster ovary cell mutant (Lec2) that express much less sialic acid on the surface than the parental cell line (Pro5) to investigate whether sialic acid plays a role during cell invasion by Trypanosoma cruzi. Trypomastigotes derived from a tissue culture (corresponding to bloodstream trypomastigotes) and metacyclic trypomastigotes (corresponding to infective stages of the insect vector) invaded the Lec2 mutant less efficiently than the parental cell line. Invasion of th...

  11. Molecular analysis of early host cell infection by Trypanosoma cruzi

    Villalta, Fernando; Madison, M. Nia; Kleshchenko, Yuliya Y.; Nde, Pius N.; Lima, Maria F.

    2008-01-01

    Trypanosoma cruzi, the causative agent of Chagas heart disease, infects heart and other cells leading to cardiac arrest frequently followed by death (1). The disease affects millions of individuals in the Americas and is posing health problems because of blood transmission in the US due to large Latin American immigration (2–3). Since the current drugs present serious side effects and do not cure the chronic infection (4), it is critically important to understand the early process of cellular...

  12. Cloning and characterization of Trypanosoma cruzi antigens bearing repetitive epitopes

    The genes of Trypanosoma cruzi, the causative agent of Chagas Disease, were cloned in the expression vector lambda gt11, and screened with a trypamastigote antiserum. Twelve clones expressing fusion proteins reacting to the antiserum were selected and further analysed in the western blot. One clone (7/2) expressing an antigen present in the cytoplasm of the parasite was found to react specifically with chagasic sera and may have potential as an immunodiagnostic reagent. (author). 11 refs, 4 figs

  13. Characterization of a RAB5 homologue in Trypanosoma cruzi

    RAB proteins are small GTPases involved in exocytic and endocytic pathways of eukaryotic cells, controlling vesicle docking and fusion. RABs show a remarkable specificity in subcellular localization, so they can be used as molecular markers for studying protein trafficking in Trypanosoma cruzi, the causal agent of Chagas' disease. RAB5 is a component of early endosomes. It has been identified in kinetoplastids such as Trypanosoma brucei and Leishmania donovani. In this work, we describe the characterization of the complete coding sequence of a RAB5 gene homologue in T. cruzi (TcRAB5, GenBank Accession No. AY730667). It is present as a single copy gene, located at chromosomal bands XIII and XIV. TcRAB5 shares the highest degrees of similarity (71%) and identity (63%) with Trypanosoma brucei rhodesiense RAB5a and contains all five characteristic RAB motifs. TcRAB5 is transcribed as a single 1.5kb mRNA in epimastigotes. Its transcript was also detected in the other two forms of the parasite, metacyclic trypomastigotes and spheromastigotes. The recombinant TcRAB5 protein was able to bind and hydrolyze GTP. The identification of proteins involved in T. cruzi endo- and exocytic pathways may generate cellular compartment markers, an invaluable tool to better understand the vesicular transport in this parasite

  14. Genitourinary changes in hamsters infected and reinfected with Trypanosoma cruzi

    Cabrine-Santos Marlene

    2003-01-01

    Full Text Available Authors describe genitourinary changes in male hamsters infected and reinfected with Trypanosoma cruzi. Changes in genital organs have been described in human and in experimental chagasic infection. Genital dysfunctions in chronic chagasic patients affect ejaculation, libido and sexual potency, and testis biopsies may show arrested maturation of germ cells, oligozoospermia and azoospermia. Sixty-five male hamsters were inoculated and reinoculated with 2x10³ trypomastigotes of T. cruzi VIC strain, and 22 non-infected animals constituted the control group. Animals were necropsied and fragments from testis, epididymis, seminal vesicle and bladder were collected and stained with hematoxylin-eosin. Peroxidase anti-peroxidase procedure was utilized to detect tissue parasitism. T. cruzi nests were found in testis, epididymis and seminal vesicle of these hamsters. Such parasitism plays a role in the origin of genital lesions observed in humans and laboratory animals during chronic chagasic infection.

  15. Vitamin C effects in mice experimentally infected with Trypanosoma cruzi QM2 strain

    Alex Silva de Gusmão; Roberto Esteves Pires Castanho; Rodrigo Franzoso Almeida de Andrade; Clarisse Moreno Farsetti; Andressa Boim Mathias; Altino Luiz Silva Therezo; Luciamáre Perinetti Alves Martins

    2012-01-01

    INTRODUCTION: To evaluate the efficacy of vitamin C in reducing the consequences generated by the production of free radicals in the acute and chronic phases of Chagas disease, two different doses of ascorbic acid were administered orally to 60 mice infected by Trypanosoma cruzi QM2 strain. METHODS: The animals were divided into six groups: G1, G2, and G3 for the acute phase study, and G'1, G'2, and G'3 for the chronic stage. The groups G1 and G'1 received 8.6x10-4mg/g of vitamin C daily, whe...

  16. Influence of ionizing radiation on Trypanosoma cruzi

    Chagas' disease is among the major health problems in South America impairing the wealth fare population. Since its discovery, in 1909, by Carlos Chagas, American Trypanosomiasis showed significant differences in the resistance of infected people. Such observations led to the hypothesis that the genetic background of the host could have an influence on the development of the disease and lifespan of infected people. Considering that ionizing radiation has been successfully employed to modify the immunological properties of biomolecules studies, this paper reports on results obtained by comparing infectivity and immunogenicity of native and irradiated T. cruzi. It was observed that radiation process causes inability of trypanosomes to infect and kill mice, however these results are different according to the strain mice studied. Different strains were immunized with native T. cruzi or 2 KGy irradiated parasite in a 60 Co source with 103 or 105 forms. The results obtained by ELISA method indicated that when immunized with native T. cruzi, all different strain mice have produced significant antibodies title levels. However, if irradiated parasite is employed, smaller antibodies title is observed. These results indicate that ionizing radiation is a good tool to modify T. cruzi in order to get a less infective parasite, considering that although susceptible mice strain have presented no significant immune response, they did not die. These data could help to understand the immune mechanisms involved in recognition, processing and presentation of both native and irradiated parasites. (author)

  17. Identification of the nicotinamide mononucleotide adenylyltransferase of Trypanosoma cruzi

    Niño, Carlos H; Forero-Baena, Nicolás; Contreras, Luis E; Sánchez-Lancheros, Diana; Figarella, Katherine; Ramírez, María H

    2015-01-01

    The intracellular parasite Trypanosoma cruzi is the aetiological agent of Chagas disease, a public health concern with an increasing incidence rate. This increase is due, among other reasons, to the parasite's drug resistance mechanisms, which require nicotinamide adenine dinucleotide (NAD+). Furthermore, this molecule is involved in metabolic and intracellular signalling processes necessary for the survival of T. cruzi throughout its life cycle. NAD+ biosynthesis is performed by de novo and salvage pathways, which converge on the step that is catalysed by the enzyme nicotinamide mononucleotide adenylyltransferase (NMNAT) (enzyme commission number: 2.7.7.1). The identification of the NMNAT of T. cruzi is important for the development of future therapeutic strategies to treat Chagas disease. In this study, a hypothetical open reading frame (ORF) for NMNAT was identified in the genome of T. cruzi. The corresponding putative protein was analysed by simulating structural models. The ORF was amplified from genomic DNA by polymerase chain reaction and was further used for the construction of a corresponding recombinant expression vector. The expressed recombinant protein was partially purified and its activity was evaluated using enzymatic assays. These results comprise the first identification of an NMNAT in T. cruzi using bioinformatics and experimental tools and hence represent the first step to understanding NAD+ metabolism in these parasites. PMID:26560979

  18. Transcriptional and phenotypical heterogeneity of Trypanosoma cruzi cell populations.

    Seco-Hidalgo, Víctor; De Pablos, Luis Miguel; Osuna, Antonio

    2015-12-01

    Trypanosoma cruzi has a complex life cycle comprising pools of cell populations which circulate among humans, vectors, sylvatic reservoirs and domestic animals. Recent experimental evidence has demonstrated the importance of clonal variations for parasite population dynamics, survival and evolution. By limiting dilution assays, we have isolated seven isogenic clonal cell lines derived from the Pan4 strain of T. cruzi. Applying different molecular techniques, we have been able to provide a comprehensive characterization of the expression heterogeneity in the mucin-associated surface protein (MASP) gene family, where all the clonal isogenic populations were transcriptionally different. Hierarchical cluster analysis and sequence comparison among different MASP cDNA libraries showed that, despite the great variability in MASP expression, some members of the transcriptome (including MASP pseudogenes) are conserved, not only in the life-cycle stages but also among different strains of T. cruzi. Finally, other important aspects for the parasite, such as growth, spontaneous metacyclogenesis or excretion of different catabolites, were also compared among the clones, demonstrating that T. cruzi populations of cells are also phenotypically heterogeneous. Although the evolutionary strategy that sustains the MASP expression polymorphism remains unknown, we suggest that MASP clonal variability and phenotypic heterogeneities found in this study might provide an advantage, allowing a rapid response to environmental pressure or changes during the life cycle of T. cruzi. PMID:26674416

  19. Towards an understanding of the interactions of Trypanosoma cruzi and Trypanosoma rangeli within the reduviid insect host Rhodnius prolixus

    Patrícia Azambuja; Norman A. Ratcliffe; Garcia, Eloi S.

    2005-01-01

    This review outlines aspects on the developmental stages of Trypanosoma cruzi and Trypanosoma rangeli in the invertebrate host, Rhodnius prolixus. Special attention is given to the interactions of these parasites with gut and hemolymph molecules and the effects of the organization of midgut epithelial cells on the parasite development. The vector insect's permissiveness to T. cruzi, which develops in the vector gut, largely depends on the host nutritional state, the parasite strain and the mo...

  20. Occurrence of Trypanosoma cruzi in Maryland

    Herman, C.M.; Bruce, J.I., Jr.

    1962-01-01

    During 1954-1960, 2005 mammals of 18 species collected at the Patuxent Wildlife Research Center, Maryland, were examined for trypanosomes. T. cruzi was found in 10 raccoons between October 31 and November 30. Infection occurred in 2 percent of all raccoons sampled, and in 11.3 percent of the 80 raccoons sampled in November. Examination was by direct smears, stained smears and cultures of heart blood. Although, in previous studies, at least two experimentally infected raccoons exhibited extended parasitemia (14 and 8 weeks), no such continuing parasitemia was observed in the natural infections. No trypanosomes were found in any of the other mammals examined.

  1. Aspirin treatment exacerbates oral infections by Trypanosoma cruzi.

    Cossentini, Luana Aparecida; Da Silva, Rosiane Valeriano; Yamada-Ogatta, Sueli Fumie; Yamauchi, Lucy Megumi; De Almeida Araújo, Eduardo José; Pinge-Filho, Phileno

    2016-05-01

    Oral transmission of the protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas disease, has been documented in Latin American countries. The reported cases of infection were due to the ingestion of contaminated fresh fruit, juices, or sugar cane juice. There have been few studies on the physiopathology of the disease in oral transmission cases. Gastritis is a common ailment that can be caused by poor dietary habits, intake of alcohol or other gastric irritants, bacterial infection, or by the widespread use of non-steroidal anti-inflammatory drugs (NSAIDs). This study investigated in a mouse model whether gastric mucosal injury, induced by aspirin, would affect the course of disease in animals infected with T. cruzi by the oral route. The CL14 and G strains of T. cruzi, both of low infectivity, were used. To this end, groups of BALB/c mice were treated during 5 days with aspirin (100 mg kg(-1)) before oral infection with T. cruzi metacyclic forms (4 × 10(5) or 5 × 10(7) parasites/mouse). Histological analysis and determination of nitric oxide and TNF-α were performed in gastric samples obtained 5 days after infection. Parasitemia was monitored from the thirteenth day after infection. The results indicate that aspirin treatment of mice injured their gastric mucosa and facilitated invasion by both CL14 and G strains of T. cruzi. Strain CL14 caused more severe infection compared to the G strain, as larger numbers of amastigote nests were found in the stomach and parasitemia levels were higher. Our study is novel in that it shows that gastric mucosal damage caused by aspirin, a commonly used NSAID, facilitates T. cruzi infection by the oral route. PMID:26826555

  2. Oral transmission of Chagas disease: importance of Trypanosoma cruzi biodeme in the intragastric experimental infection.

    Camandaroba, Edson Luiz P; Pinheiro Lima, Clarissa M; Andrade, Sonia G

    2002-01-01

    Oral transmission of Trypanosoma cruzi has been suspected when epidemic episodes of acute infection were observed in areas devoid of domiciled insect vectors. Considering that the distribution of T. cruzi biodemes differs in sylvatic and domestic cycles, results of studies on biodemes can be of interest regarding oral transmission. The infectivity of T. cruzi strains of different biodemes was tested in mice subjected to infection by the digestive route (gavage). Swiss mice were infected either with the Peruvian strain (Biodeme Type I, Z2b) or the Colombian strain (Biodeme Type III, Z1, or T. cruzi I); for control, intraperitoneal inoculation was performed in a group of mice. The Colombian strain revealed a similar high infectivity and pathogenicity when either route of infection was used. However, the Peruvian strain showed contrasting levels of infectivity and pathogenicity, being high by intraperitoneal inoculation and low when the gastric route was used. The higher infectivity of the Colombian strain (Biodeme Type III) by gastric inoculation is in keeping with its role in the epidemic episodes of acute Chagas disease registered in the literature, since strains belonging to Biodeme III are most often found in sylvatic hosts. PMID:12048547

  3. Oral transmission of Chagas disease: importance of Trypanosoma cruzi biodeme in the intragastric experimental infection

    CAMANDAROBA Edson Luiz P.

    2002-01-01

    Full Text Available Oral transmission of Trypanosoma cruzi has been suspected when epidemic episodes of acute infection were observed in areas devoid of domiciled insect vectors. Considering that the distribution of T. cruzi biodemes differs in sylvatic and domestic cycles, results of studies on biodemes can be of interest regarding oral transmission. The infectivity of T. cruzi strains of different biodemes was tested in mice subjected to infection by the digestive route (gavage. Swiss mice were infected either with the Peruvian strain (Biodeme Type I, Z2b or the Colombian strain (Biodeme Type III, Z1, or T. cruzi I; for control, intraperitoneal inoculation was performed in a group of mice. The Colombian strain revealed a similar high infectivity and pathogenicity when either route of infection was used. However, the Peruvian strain showed contrasting levels of infectivity and pathogenicity, being high by intraperitoneal inoculation and low when the gastric route was used. The higher infectivity of the Colombian strain (Biodeme Type III by gastric inoculation is in keeping with its role in the epidemic episodes of acute Chagas disease registered in the literature, since strains belonging to Biodeme III are most often found in sylvatic hosts.

  4. Electron Microscopy Analysis of the Nucleolus of Trypanosoma cruzi

    López-Velázquez, Gabriel; Hernández, Roberto; López-Villaseñor, Imelda; Reyes-Vivas, Horacio; Segura-Valdez, María De L.; Jiménez-García, Luis F.

    2005-08-01

    The nucleolus is the main site for synthesis and processing of ribosomal RNA in eukaryotes. In mammals, plants, and yeast the nucleolus has been extensively characterized by electron microscopy, but in the majority of the unicellular eukaryotes no such studies have been performed. Here we used ultrastructural cytochemical and immunocytochemical techniques as well as three-dimensional reconstruction to analyze the nucleolus of Trypanosoma cruzi, which is an early divergent eukaryote of medical importance. In T. cruzi epimastigotes the nucleolus is a spherical intranuclear ribonucleoprotein organelle localized in a relatively central position within the nucleus. Dense fibrillar and granular components but not fibrillar centers were observed. In addition, nuclear bodies resembling Cajal bodies were observed associated to the nucleolus in the surrounding nucleoplasm. Our results provide additional morphological data to better understand the synthesis and processing of the ribosomal RNA in kinetoplastids.

  5. Purification and Partial characterization of Trypanosoma cruzi triosephosphate isomerase.

    Bourguignon, S C; Meirelles, M N; Pacheco, R S; De Simone, S G

    1998-01-01

    The enzyme triosephosphate isomerase (TPI, EC 5.3.1.1) was purified from extracts of epimastigote forms of Trypanosoma cruzi. The purification steps included: hydrophobic interaction chromatography on phenyl-Sepharose, CM-Sepharose, and high performance liquid gel filtration chromatography. The CM-Sepharose material contained two bands (27 and 25 kDa) with similar isoelectric points (pI 9.3-9.5) which could be separated by gel filtration in high performance liquid chromatography. Polyclonal antibodies raised against the porcine TPI detected one single polypeptide on western blot with a molecular weight (27 kDa) identical to that purified from T. cruzi. These antibodies also recognized only one band of identical molecular weight in western blots of several other trypanosomatids (Blastocrithidia culicis, Crithidia desouzai, Phytomonas serpens, Herpertomonas samuelpessoai). The presence of only one enzymatic form of TPI in T. cruzi epimastigotes was confirmed by agarose gel activity assay and its localization was established by immunocytochemical analysis. The T. cruzi purified TPI (as well as other trypanosomatid' TPIs) is a dimeric protein, composed of two identical subunits with an approximate mw of 27,000 and it is resolved on two dimensional gel electrophoresis with a pI of 9.3. Sequence analysis of the N-terminal portion of the 27 kDa protein revealed a high homology to Leishmania mexicana and T. brucei proteins. PMID:9698898

  6. Diterpenoids from Azorella compacta (Umbelliferae active on Trypanosoma cruzi

    Araya Jorge E

    2003-01-01

    Full Text Available The anti-Trypanosoma cruzi activity of natural products isolated from Azorella compacta was evaluated, with particular emphasis on their effect against intracellular amastigotes. Five diterpenoids from A. compacta derived from mulinane and azorellane were isolated and identified. Only two products, named azorellanol (Y-2 and mulin-11,3-dien-20-oic acid (Y-5, showed trypanocidal activity against all stages of T. cruzi including intracellular amastigotes. At 10 µM, these compounds displayed a strong lytic activity. It ranged from 88.4 ± 0.6 to 99.0 ± 1 % for all strains and stages evaluate, with an IC50 /18 h values of 20-84 µM and 41-87 µM, respectively. The development of intracellular amastigotes was also inhibited by nearly 60% at 25 µM. The trypanocidal molecules Y-2 and Y-5 did show different degrees of cytotoxicity depending on the cell line tested, with an IC50 /24 h ranging from 33.2 to 161.2 µM. We evaluated the effect of diterpenoids against intracellular T. cruzi forms by immunofluorescent identification of a specific membrane molecular marker (Ssp-4 antigen of the T. cruzi amastigote forms. The accuracy and reproducibility of the measurements were found to be outstanding when examined by confocal microscopy.

  7. Environment, interactions between Trypanosoma cruzi and its host, and health.

    Teixeira, Antonio R L; Gomes, Clever; Lozzi, Silene P; Hecht, Mariana M; Rosa, Ana de Cássia; Monteiro, Pedro S; Bussacos, Ana Carolina; Nitz, Nadjar; McManus, Concepta

    2009-01-01

    An epidemiological chain involving Trypanosoma cruzi is discussed at the environmental level, and in terms of fine molecular interactions in invertebrate and vertebrate hosts dwelling in different ecosystems. This protozoan has a complex, genetically controlled plasticity, which confers adaptation to approximately 40 blood-sucking triatomine species and to over 1,000 mammalian species, fulfilling diverse metabolic requirements in its complex life-cycle. The Tr. cruzi infections are deeply embedded in countless ecotypes, where they are difficult to defeat using the control methods that are currently available. Many more field and laboratory studies are required to obtain data and information that may be used for the control and prevention of Tr. cruzi infections and their various disease manifestations. Emphasis should be placed on those sensitive interactions at cellular and environmental levels that could become selected targets for disease prevention. In the short term, new technologies for social mobilization should be used by people and organizations working for justice and equality through health information and promotion. A mass media directed program could deliver education, information and communication to protect the inhabitants at risk of contracting Tr. cruzi infections. PMID:19287864

  8. Purification and Partial Characterization of Trypanosoma cruzi Triosephosphate Isomerase

    Bourguignon SC

    1998-01-01

    Full Text Available The enzyme triosephosphate isomerase (TPI, EC 5.3.1.1 was purified from extracts of epimastigote forms of Trypanosoma cruzi. The purification steps included: hydrophobic interaction chromatography on phenyl-Sepharose, CM-Sepharose, and high performance liquid gel filtration chromatography. The CM-Sepharose material contained two bands (27 and 25 kDa with similar isoelectric points (pI 9.3-9.5 which could be separated by gel filtration in high performance liquid chromatography. Polyclonal antibodies raised against the porcine TPI detected one single polypeptide on western blot with a molecular weight (27 kDa identical to that purified from T. cruzi. These antibodies also recognized only one band of identical molecular weight in western blots of several other trypanosomatids (Blastocrithidia culicis, Crithidia desouzai, Phytomonas serpens, Herpertomonas samuelpessoai. The presence of only one enzymatic form of TPI in T. cruzi epimastigotes was confirmed by agarose gel activity assay and its localization was established by immunocytochemical analysis. The T. cruzi purified TPI (as well as other trypanosomatid' TPIs is a dimeric protein, composed of two identical subunits with an approximate mw of 27,000 and it is resolved on two dimensional gel electrophoresis with a pI of 9.3. Sequence analysis of the N-terminal portion of the 27 kDa protein revealed a high homology to Leishmania mexicana and T. brucei proteins

  9. Production of amastigotes from metacyclic trypomastigotes of Trypanosoma cruzi

    Víctor T Contreras

    2002-12-01

    Full Text Available Attempts to recreate all the developmental stages of Trypanosoma cruzi in vitro have thus far been met with partial success. It is possible, for instance, to produce trypomastigotes in tissue culture and to obtain metacyclic trypomastigotes in axenic conditions. Even though T. cruzi amastigotes are known to differentiate from trypomastigotes and metacyclic trypomastigotes, it has only been possible to generate amastigotes in vitro from the tissue-culture-derived trypomastigotes. The factors and culture conditions required to trigger the transformation of metacyclic trypomastigotes into amastigotes are as yet undetermined. We show here that pre-incubation of metacyclic trypomastigotes in culture (MEMTAU medium at 37°C for 48 h is sufficient to commit the parasites to the transformation process. After 72 h of incubation in fresh MEMTAU medium, 90% of the metacyclic parasites differentiate into forms that are morphologically indistinguishable from normal amastigotes. SDS-PAGE, Western blot and PAABS analyses indicate that the transformation of axenic metacyclic trypomastigotes to amastigotes is associated with protein, glycoprotein and antigenic modifications. These data suggest that (a T. cruzi amastigotes can be obtained axenically in large amounts from metacyclic trypomastigotes, and (b the amastigotes thus obtained are morphological, biological and antigenically similar to intracellular amastigotes. Consequently, this experimental system may facilitate a direct, in vitro assessment of the mechanisms that enable T. cruzi metacyclic trypomastigotes to transform into amastigotes in the cells of mammalian hosts.

  10. AUMENTO DA EXPRESSÃO DE ?-CATENINA E CADERINA NO CORAÇÃO DE CAMUNDONGOS NA FASE AGUDA E CRÔNICA DA INFECÇÃO EXPERIMENTAL POR Trypanosoma cruzi UPREGULATION OF ?-CATENIN AND CADHERIN EXPRESSION IN HEARTS OF MICE IN ACUTE AND CHRONIC PHASE OF EXPERIMENTAL Trypanosoma cruzi infection

    Tatyane Penha Sales; Maria Clorinda Soares Fioravanti; João Roberto Mata; Eugênio Gonçalves Araújo; Adilson Donizeti Damasceno; Fernando José Gondim Peixoto

    2008-01-01

    As proteínas das junções de aderência têm sido associadas ao mecanismo patológico da miocardiopatia chagásica. Objetivando determinar a natureza dessas alterações, infectaram-se dez camundongos machos Swiss Webster com 25 dias de idade por via intraperitoneal com uma cepa tipo III de Trypanosoma cruzi na dose de 1,0 x 104 tripomastigotas/camundongo. Cinco camundongos infectados foram sacrificados no 14° dia (pico de parasitemia) de infecção (grupo A) e outros cinco camundongos (grupo C) três ...

  11. Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula.

    López-Cancino, Sury Antonio; Tun-Ku, Ezequiel; De la Cruz-Felix, Himmler Keynes; Ibarra-Cerdeña, Carlos Napoleón; Izeta-Alberdi, Amaia; Pech-May, Angélica; Mazariegos-Hidalgo, Carlos Jesús; Valdez-Tah, Alba; Ramsey, Janine M

    2015-11-01

    Landscape interactions of Trypanosoma cruzi (Tc) with Triatoma dimidiata (Td) depend on the presence and relative abundance of mammal hosts. This study analyzed a landscape adjacent to the Calakmul Biosphere Reserve, composed of conserved areas, crop and farming areas, and the human community of Zoh Laguna with reported Chagas disease cases. Sylvatic mammals of the Chiroptera, Rodentia, and Marsupialia orders were captured, and livestock and pets were sampled along with T. dimidiata in all habitats. Infection by T. cruzi was analyzed using mtDNA markers, while lineage and DTU was analyzed using the mini-exon. 303 sylvatic specimens were collected, corresponding to 19 species during the rainy season and 114 specimens of 18 species during dry season. Five bats Artibeus jamaicensis, Artibeus lituratus, Sturnira lilium, Sturnira ludovici, Dermanura phaeotis (Dp) and one rodent Heteromys gaumeri were collected in the three habitats. All but Dp, and including Carollia brevicauda and Myotis keaysi, were infected with predominately TcI in the sylvatic habitat and TcII in the ecotone. Sigmodon hispidus was the rodent with the highest prevalence of infection by T. cruzi I and II in ecotone and domestic habitats. Didelphis viginiana was infected only with TcI in both domestic and sylvatic habitats; the only two genotyped human cases were TcII. Two main clades of T. cruzi, lineages I (DTU Ia) and II (DTU VI), were found to be sympatric (all habitats and seasons) in the Zoh-Laguna landscape, suggesting that no species-specific interactions occur between the parasite and any mammal host, in any habitat. We have also found mixed infections of the two principal T. cruzi clades in individuals across modified habitats, particularly in livestock and pets, and in both haplogroups of T. dimidiata. Results are contradictory to the dilution hypothesis, although we did find that most resilient species had an important role as T. cruzi hosts. Our study detected some complex trends in

  12. Nitric oxide-releasing polymeric nanoparticles against Trypanosoma cruzi

    Seabra, A. B.; Kitice, N. A.; Pelegrino, M. T.; Lancheros, C. A. C.; Yamauchi, L. M.; Pinge-Filho, P.; Yamada-Ogatta, S. F.

    2015-05-01

    Chagas disease, also known as American trypanosomiasis, is a potentially life-threatening illness caused by the protozoan parasite, Trypanosoma cruzi (T. cruzi), and the disease remains a major health problem in many Latin American countries. Several papers report that the killing of the parasite is dependent on the production of nitric oxide (NO). The endogenous free radical NO is an important cellular signalling molecule that plays a key role in the defense against pathogens, including T. cruzi. As T. cruzi is able to compromise host macrophages decreasing endogenous NO production, the administration of exogenous NO donors represents an interesting strategy to combat Chagas disease. Thus, the aims of this study were to prepare and evaluate the antimicrobial activity of NO-releasing polymeric nanoparticles against T. cruzi. Biocompatible polymeric nanoparticles composed of chitosan/sodium tripolyphosphate(TPP) were prepared and used to encapsulate mercaptosuccinic acid (MSA), which is a thiol-containing molecule. Nitrosation of free thiols (SH) groups of MSA were performed by the addition of equimolar amount of sodium nitrite (NaNO2), leading to the formation of S-nitroso-MSA-containing nanoparticles. These polymeric nanoparticles act as spontaneous NO donors, with free NO release. The results show the formation of nanoparticles with average hydrodynamic diameter ranging from 270 to 500 nm, average of polydispersity index of 0.35, and encapsulation efficiency in the range of 99%. The NO release kinetics from the S-nitroso-MSA-containing nanoparticles showed sustained and controlled NO release over several hours. The microbicidal activity of S-nitroso-MSA-containing nanoparticles was evaluated by incubating NO-releasing nanoparticles (200 - 600 μg/mL) with replicative and non-infective epimastigote, and non-replicative and infective trypomastigote forms of T. cruzi. In addition, a significant decrease in the percentage of macrophage-infected (with amastigotes) and

  13. The potential of canine sentinels for reemerging Trypanosoma cruzi transmission

    Neyra, Ricardo Castillo; Chu, Lily Chou; Quispe-Machaca, Victor; Ancca-Juarez, Jenny; Malaga Chavez, Fernando S.; Mazuelos, Milagros Bastos; Naquira, Cesar; Bern, Caryn; Gilman, Robert H.; Levy, Michael Z.

    2015-01-01

    Background Chagas disease, a vector-borne disease transmitted by triatomine bugs and caused by the parasite Trypanosoma cruzi, affects millions of people in the Americas. In Arequipa, Peru, indoor residual insecticide spraying campaigns are routinely conducted to eliminate Triatoma infestans, the only vector in this area. Following insecticide spraying, there is risk of vector return and reinitiation of parasite transmission. Dogs are important reservoirs of T. cruzi and may play a role in reinitiating transmission in previously sprayed areas. Dogs may also serve as indicators of reemerging transmission. Methods We conducted a cross-sectional serological screening to detect T. cruzi antibodies in dogs, in conjunction with an entomological vector collection survey at the household level, in a disease endemic area that had been treated with insecticide 13 years prior. Spatial clustering of infected animals and vectors was assessed using Ripley’s K statistic, and the odds of being seropositive for dogs proximate to infected colonies was estimated with multivariate logistic regression. Results There were 106 triatomine-infested houses (41.1%), and 45 houses infested with T. cruzi-infected triatomine insects (17.4%). Canine seroprevalence in the area was 12.3% (n=154); all seropositive dogs were 9 months old or older. We observed clustering of vectors carrying the parasite, but no clustering of seropositive dogs. The age- and sex-adjusted odds ratio between seropositivity to T. cruzi and proximity to an infected triatomine (≤50m) was 5.67 (95% CI: 1.12 – 28.74; p=0.036). Conclusions Targeted control of reemerging transmission can be achieved by improved understanding of T. cruzi in canine populations. Our results suggest that dogs may be useful sentinels to detect re-initiation of transmission following insecticide treatment. Integration of canine T. cruzi blood sampling into existing interventions for zoonotic disease control (e.g. rabies vaccination programs

  14. Effects of betamethasone on the course of experimentai. Infection with Trypanosoma cruzi

    Frederico G.C. Abath

    1986-09-01

    Full Text Available In this experiment, the effect of betamethasone administered in the early post- acute infection of mice by Trypanosoma cruzi was studied. This drug was administered during 30 days after the 42nd day of infection in a dose of 0.15 mg/day. The betamethasone treatment did not cause fresh outbreaks of parasitemia and the histopathological findings in the chronic phase were not different from those in the control group. The higher cumulative mortality after treatment in the experimental group was due to superimposed bacterial infections. Outbred albino mice infected with low numbers ofY strain Trypanosoma cruzi trypomastigotes were not suitable models for Chagas' disease, since after 7 months of observation only mild histological lesions developed in all the animais. Prolonged betamethasone treatment of mice infected with low numbers o/Trypanosoma cruzi of the Y strain, during the post-acute phase did not aggravate the course of infection.Foram estudados os efeitos da betametasona administrada na fase pós-aguda imediata de uma infecção pelo T. cruzi em camundongos. O tratamento consistiu de 30 doses diárias de 0,15 mg de betametasona, a partir de 42° dia de infecção, não havendo aparecimento de novos surtos de parasitemia. No tempo de duração do experimento (7 meses não houve diferença entre as lesões histopatológicas dos animais tratados e dos não tratados. O grupo experimental apresentou uma maior mortalidade acumulada no 75º dia de infecção, o que pode ser atribuído a infecções bacterianas associadas. Por outro lado, camundongos albinos "outbred", infectados com baixo inóculo, não se apresentaram como bom modelo de doença de Chagas, já que não desenvolveram lesões importantes nem na fase aguda nem após 7 meses de infecção. Em conclusão, o tratamento imunosupressivo prolongado, após a fase aguda de uma infecção mínima com a cepa Ydo T. cruzi não tem influência sobre o curso da infecção, pelo menos no que tange

  15. Oxidative stress fuels Trypanosoma cruzi infection in mice

    Paiva, Claudia N.; Feijó, Daniel F.; Dutra, Fabianno F.; Carneiro, Vitor C.; Freitas, Guilherme B.; Alves, Letícia S.; Mesquita, Jacilene; Fortes, Guilherme B.; Figueiredo, Rodrigo T.; Souza, Heitor S.P.; Fantappié, Marcelo R.; Lannes-Vieira, Joseli; Bozza, Marcelo T.

    2012-01-01

    Oxidative damage contributes to microbe elimination during macrophage respiratory burst. Nuclear factor, erythroid-derived 2, like 2 (NRF2) orchestrates antioxidant defenses, including the expression of heme-oxygenase–1 (HO-1). Unexpectedly, the activation of NRF2 and HO-1 reduces infection by a number of pathogens, although the mechanism responsible for this effect is largely unknown. We studied Trypanosoma cruzi infection in mice in which NRF2/HO-1 was induced with cobalt protoporphyrin (CoPP). CoPP reduced parasitemia and tissue parasitism, while an inhibitor of HO-1 activity increased T. cruzi parasitemia in blood. CoPP-induced effects did not depend on the adaptive immunity, nor were parasites directly targeted. We also found that CoPP reduced macrophage parasitism, which depended on NRF2 expression but not on classical mechanisms such as apoptosis of infected cells, induction of type I IFN, or NO. We found that exogenous expression of NRF2 or HO-1 also reduced macrophage parasitism. Several antioxidants, including NRF2 activators, reduced macrophage parasite burden, while pro-oxidants promoted it. Reducing the intracellular labile iron pool decreased parasitism, and antioxidants increased the expression of ferritin and ferroportin in infected macrophages. Ferrous sulfate reversed the CoPP-induced decrease in macrophage parasite burden and, given in vivo, reversed their protective effects. Our results indicate that oxidative stress contributes to parasite persistence in host tissues and open a new avenue for the development of anti–T. cruzi drugs. PMID:22728935

  16. Conservation and divergence within the clathrin interactome of Trypanosoma cruzi.

    Kalb, Ligia Cristina; Frederico, Yohana Camila A; Boehm, Cordula; Moreira, Claudia Maria do Nascimento; Soares, Maurilio José; Field, Mark C

    2016-01-01

    Trypanosomatids are parasitic protozoa with a significant burden on human health. African and American trypanosomes are causative agents of Nagana and Chagas disease respectively, and speciated about 300 million years ago. These parasites have highly distinct life cycles, pathologies, transmission strategies and surface proteomes, being dominated by the variant surface glycoprotein (African) or mucins (American) respectively. In African trypanosomes clathrin-mediated trafficking is responsible for endocytosis and post-Golgi transport, with several mechanistic aspects distinct from higher organisms. Using clathrin light chain (TcCLC) and EpsinR (TcEpsinR) as affinity handles, we identified candidate clathrin-associated proteins (CAPs) in Trypanosoma cruzi; the cohort includes orthologs of many proteins known to mediate vesicle trafficking, but significantly not the AP-2 adaptor complex. Several trypanosome-specific proteins common with African trypanosomes, were also identified. Fluorescence microscopy revealed localisations for TcEpsinR, TcCLC and TcCHC at the posterior region of trypomastigote cells, coincident with the flagellar pocket and Golgi apparatus. These data provide the first systematic analysis of clathrin-mediated trafficking in T. cruzi, allowing comparison between protein cohorts and other trypanosomes and also suggest that clathrin trafficking in at least some life stages of T. cruzi may be AP-2-independent. PMID:27502971

  17. High throughput selection of effective serodiagnostics for Trypanosoma cruzi infection.

    Gretchen Cooley

    Full Text Available BACKGROUND: Diagnosis of Trypanosoma cruzi infection by direct pathogen detection is complicated by the low parasite burden in subjects persistently infected with this agent of human Chagas disease. Determination of infection status by serological analysis has also been faulty, largely due to the lack of well-characterized parasite reagents for the detection of anti-parasite antibodies. METHODS: In this study, we screened more than 400 recombinant proteins of T. cruzi, including randomly selected and those known to be highly expressed in the parasite stages present in mammalian hosts, for the ability to detect anti-parasite antibodies in the sera of subjects with confirmed or suspected T. cruzi infection. FINDINGS: A set of 16 protein groups were identified and incorporated into a multiplex bead array format which detected 100% of >100 confirmed positive sera and also documented consistent, strong and broad responses in samples undetected or discordant using conventional serologic tests. Each serum had a distinct but highly stable reaction pattern. This diagnostic panel was also useful for monitoring drug treatment efficacy in chronic Chagas disease. CONCLUSIONS: These results substantially extend the variety and quality of diagnostic targets for Chagas disease and offer a useful tool for determining treatment success or failure.

  18. Trypanosoma cruzi infection in neotropical wild carnivores (Mammalia: Carnivora: at the top of the T. cruzi transmission chain.

    Fabiana Lopes Rocha

    Full Text Available Little is known on the role played by Neotropical wild carnivores in the Trypanosoma cruzi transmission cycles. We investigated T. cruzi infection in wild carnivores from three sites in Brazil through parasitological and serological tests. The seven carnivore species examined were infected by T. cruzi, but high parasitemias detectable by hemoculture were found only in two Procyonidae species. Genotyping by Mini-exon gene, PCR-RFLP (1f8/Akw21I and kDNA genomic targets revealed that the raccoon (Procyon cancrivorus harbored TcI and the coatis (Nasua nasua harbored TcI, TcII, TcIII-IV and Trypanosoma rangeli, in single and mixed infections, besides four T. cruzi isolates that displayed odd band patterns in the Mini-exon assay. These findings corroborate the coati can be a bioaccumulator of T. cruzi Discrete Typing Units (DTU and may act as a transmission hub, a connection point joining sylvatic transmission cycles within terrestrial and arboreal mammals and vectors. Also, the odd band patterns observed in coatis' isolates reinforce that T. cruzi diversity might be much higher than currently acknowledged. Additionally, we assembled our data with T. cruzi infection on Neotropical carnivores' literature records to provide a comprehensive analysis of the infection patterns among distinct carnivore species, especially considering their ecological traits and phylogeny. Altogether, fifteen Neotropical carnivore species were found naturally infected by T. cruzi. Species diet was associated with T. cruzi infection rates, supporting the hypothesis that predator-prey links are important mechanisms for T. cruzi maintenance and dispersion in the wild. Distinct T. cruzi infection patterns across carnivore species and study sites were notable. Musteloidea species consistently exhibit high parasitemias in different studies which indicate their high infectivity potential. Mesocarnivores that feed on both invertebrates and mammals, including the coati, a host that

  19. Effect of scorpion toxin on the enterochromaffin-like cells in normal and Trypanosoma cruzi-infected rats: a morphological study

    N. H. Toppa

    1989-02-01

    Full Text Available Intravenous injection of scorpion toxin (Tityus serrulatus in normal and Trypanosoma cruzi infected rats did not cause ultrastructural morphologic changes on enterochromaffin-like (ECL cells of the stomach, although it induced a significant increase of the gastric secretion. Our data seem to indicate that gastric ECL cells structure is not affected by stimulation with scorpion toxin or by acute infection with T. cruzi in the rat.

  20. Effect of scorpion toxin on the enterochromaffin-like cells in normal and Trypanosoma cruzi-infected rats: a morphological study

    N.H. TOPPA; V. H. R. Leite; A.J.A. Barbosa; Chiari, E; H. M. S. Gonzaga; L. Freire-Maia; Cunha-Melo, J R

    1989-01-01

    Intravenous injection of scorpion toxin (Tityus serrulatus) in normal and Trypanosoma cruzi infected rats did not cause ultrastructural morphologic changes on enterochromaffin-like (ECL) cells of the stomach, although it induced a significant increase of the gastric secretion. Our data seem to indicate that gastric ECL cells structure is not affected by stimulation with scorpion toxin or by acute infection with T. cruzi in the rat.

  1. Effect of scorpion toxin on the enterochromaffin-like cells in normal and Trypanosoma cruzi-infected rats: a morphological study.

    Toppa, N H; Leite, V H; Barbosa, A J; Chiari, E; Gonzaga, H M; Freire-Maia, L; Cunha-Melo, J R

    1989-01-01

    Intravenous injection of scorpion toxin (Tityus serrulatus) in normal and Trypanosoma cruzi infected rats did not cause ultrastructural morphologic changes on enterochromaffin-like (ECL) cells of the stomach, although it induced a significant increase of the gastric secretion. Our data seem to indicate that gastric ECL cells structure is not affected by stimulation with scorpion toxin or by acute infection with T. cruzi in the rat. PMID:2510237

  2. In vitro evaluation of the activity of aromatic nitrocompounds against Trypanosoma cruzi

    Renata B Oliveira

    2003-01-01

    Full Text Available Fourteen compounds were evaluated for their activity against Trypanosoma cruzi blood stream forms at the concentration of 500 µg/ml. Six compounds were active and re-tested at lower concentrations.

  3. Vaccination with epimastigotes of different strains of Trypanosoma rangeli protects mice against Trypanosoma cruzi infection

    Beatriz Basso

    2008-06-01

    Full Text Available In our laboratory, we have developed a model of vaccination in mice with Trypanosoma rangeli, a non-pathogenic parasite that shares many antigens with Trypanosoma cruzi. The vaccinated mice were protected against infection with virulent T. cruzi. The goal of the present work was to study the protective activity of strains of T. rangeli of different origin, with the aim of analysing whether this protective capacity is a common feature of T. rangeli. BALB/c mice were vaccinated with live or fixed epimastigotes of two T. rangeli strains, Choachi and SC-58. Vaccinated (VM and control mice (CM were infected with virulent T. cruzi, Tulahuen strain. The results showed that the levels of parasitemia of VM, vaccinated with the two strains of T. rangeli were significantly lower than those developed in CM. The survival rate of VM was higher than that CM. Histological studies revealed many amastigote nests and severe inflammatory infiltrates in the heart and skeletal muscles of CM, whereas in the VM only moderate lymphomonocytic infiltrates were detected. Altogether, the results of the present work as well as previous studies show that the antigens involved in the protection induced by T. rangeli are expressed in different strains of this parasite. These findings could prove useful in vaccine preparation.

  4. Molecular basis of mammalian cell invasion by Trypanosoma cruzi

    Nobuko Yoshida

    2006-03-01

    Full Text Available Establishment of infection by Trypanosoma cruzi, the agent of Chagas' disease, depends on a series of events involving interactions of diverse parasite molecules with host components. Here we focus on the mechanisms of target cell invasion by metacyclic trypomastigotes (MT and mammalian tissue culture trypomastigotes (TCT. During MT or TCT internalization, signal transduction pathways are activated both in the parasite and the target cell, leading to Ca2+ mobilization. For cell adhesion, MT engage surface glycoproteins, such as gp82 and gp35/50, which are Ca2+ signal-inducing molecules. In T. cruzi isolates that enter host cells in gp82-mediated manner, parasite protein tyrosine kinase as well as phospholipase C are activated, and Ca2+ is released from I P3-sensitive stores, whereas in T. cruzi isolates that attach to target cells mainly through gp35/50, the signaling pathway involving adenylate cyclase appears to be stimulated, with Ca2+ release from acidocalciosomes. In addition, T. cruzi isolate-dependent inhibitory signals, mediated by MT-specific gp90, may be triggered both in the host cell and the parasite. The repertoire of TCT molecules implicated in cell invasion includes surface glycoproteins of gp85 family, with members containing binding sites for laminin and cytokeratin 18, enzymes such as cruzipain, trans-sialidase, and an oligopeptidase B that generates a Ca2+-agonist from a precursor molecule.O estabelecimento da infecção por Trypanosoma cruzi, o agente da doença de Chagas, depende de uma série de eventos envolvendo interações de diversas moléculas do parasita com componentes do hospedeiro. Focalizamos aqui os mecanismos de invasão celular por tripomastigotas metacíclicos (TM e por tripomastigotas de cultura de tecido (TCT. Durante a internalização de TM ou TCT, vias de transdução de sinal são ativadas tanto no parasita como na célula alvo, acarretando a mobilização de Ca2+. Para adesão, TM utiliza as glicoprote

  5. Alta parasitemia pelo Trypanosoma cruzi em paciente com lupus eritematoso sistêmico

    Santos-Neto Leopoldo Luiz dos; Polcheira Máira F.; Castro Cleudson; Lima Rodrigo Aires Corrêa; Simaan César Kozak; Corrêa-Lima Francisco Aires

    2003-01-01

    É descrito um caso de doença de Chagas com alta parasitemia pelo Trypanosoma cruzi em paciente com lupus eritematoso sistêmico. O xenodiagnóstico foi útil na identificação da parasitemia e o benznidazol foi capaz de reduzir a alta e incomum parasitemia. Em indivíduos com doenças auto-imunes e immunossuprimidos, o benznidazol pode ser uma alternativa no controle da alta parasitemia por Trypanosoma cruzi.

  6. Functional characterization of 8-oxoguanine DNA glycosylase of Trypanosoma cruzi.

    Carolina Furtado

    Full Text Available The oxidative lesion 8-oxoguanine (8-oxoG is removed during base excision repair by the 8-oxoguanine DNA glycosylase 1 (Ogg1. This lesion can erroneously pair with adenine, and the excision of this damaged base by Ogg1 enables the insertion of a guanine and prevents DNA mutation. In this report, we identified and characterized Ogg1 from the protozoan parasite Trypanosoma cruzi (TcOgg1, the causative agent of Chagas disease. Like most living organisms, T. cruzi is susceptible to oxidative stress, hence DNA repair is essential for its survival and improvement of infection. We verified that the TcOGG1 gene encodes an 8-oxoG DNA glycosylase by complementing an Ogg1-defective Saccharomyces cerevisiae strain. Heterologous expression of TcOGG1 reestablished the mutation frequency of the yeast mutant ogg1(-/- (CD138 to wild type levels. We also demonstrate that the overexpression of TcOGG1 increases T. cruzi sensitivity to hydrogen peroxide (H(2O(2. Analysis of DNA lesions using quantitative PCR suggests that the increased susceptibility to H(2O(2 of TcOGG1-overexpressor could be a consequence of uncoupled BER in abasic sites and/or strand breaks generated after TcOgg1 removes 8-oxoG, which are not rapidly repaired by the subsequent BER enzymes. This hypothesis is supported by the observation that TcOGG1-overexpressors have reduced levels of 8-oxoG both in the nucleus and in the parasite mitochondrion. The localization of TcOgg1 was examined in parasite transfected with a TcOgg1-GFP fusion, which confirmed that this enzyme is in both organelles. Taken together, our data indicate that T. cruzi has a functional Ogg1 ortholog that participates in nuclear and mitochondrial BER.

  7. Functional Characterization of 8-Oxoguanine DNA Glycosylase of Trypanosoma cruzi

    Mendes, Isabela Cecília; de Moura, Michelle Barbi; Campos, Priscila Carneiro; Macedo, Andrea Mara; Franco, Glória Regina; Pena, Sérgio Danilo Junho; Teixeira, Santuza Maria Ribeiro; Van Houten, Bennett; Machado, Carlos Renato

    2012-01-01

    The oxidative lesion 8-oxoguanine (8-oxoG) is removed during base excision repair by the 8-oxoguanine DNA glycosylase 1 (Ogg1). This lesion can erroneously pair with adenine, and the excision of this damaged base by Ogg1 enables the insertion of a guanine and prevents DNA mutation. In this report, we identified and characterized Ogg1 from the protozoan parasite Trypanosoma cruzi (TcOgg1), the causative agent of Chagas disease. Like most living organisms, T. cruzi is susceptible to oxidative stress, hence DNA repair is essential for its survival and improvement of infection. We verified that the TcOGG1 gene encodes an 8-oxoG DNA glycosylase by complementing an Ogg1-defective Saccharomyces cerevisiae strain. Heterologous expression of TcOGG1 reestablished the mutation frequency of the yeast mutant ogg1−/− (CD138) to wild type levels. We also demonstrate that the overexpression of TcOGG1 increases T. cruzi sensitivity to hydrogen peroxide (H2O2). Analysis of DNA lesions using quantitative PCR suggests that the increased susceptibility to H2O2 of TcOGG1-overexpressor could be a consequence of uncoupled BER in abasic sites and/or strand breaks generated after TcOgg1 removes 8-oxoG, which are not rapidly repaired by the subsequent BER enzymes. This hypothesis is supported by the observation that TcOGG1-overexpressors have reduced levels of 8-oxoG both in the nucleus and in the parasite mitochondrion. The localization of TcOgg1 was examined in parasite transfected with a TcOgg1-GFP fusion, which confirmed that this enzyme is in both organelles. Taken together, our data indicate that T. cruzi has a functional Ogg1 ortholog that participates in nuclear and mitochondrial BER. PMID:22876325

  8. Trypanosoma cruzi-Trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected Rhodnius prolixus.

    Peterson, Jennifer K; Graham, Andrea L; Elliott, Ryan J; Dobson, Andrew P; Triana Chávez, Omar

    2016-08-01

    Trypanosoma cruzi, causative agent of Chagas disease, co-infects its triatomine vector with its sister species Trypanosoma rangeli, which shares 60% of its antigens with T. cruzi. Additionally, T. rangeli has been observed to be pathogenic in some of its vector species. Although T. cruzi-T. rangeli co-infections are common, their effect on the vector has rarely been investigated. Therefore, we measured the fitness (survival and reproduction) of triatomine species Rhodnius prolixus infected with just T. cruzi, just T. rangeli, or both T. cruzi and T. rangeli. We found that survival (as estimated by survival probability and hazard ratios) was significantly different between treatments, with the T. cruzi treatment group having lower survival than the co-infected treatment. Reproduction and total fitness estimates in the T. cruzi and T. rangeli treatments were significantly lower than in the co-infected and control groups. The T. cruzi and T. rangeli treatment group fitness estimates were not significantly different from each other. Additionally, co-infected insects appeared to tolerate higher doses of parasites than insects with single-species infections. Our results suggest that T. cruzi-T. rangeli co-infection could ameliorate negative effects of single infections of either parasite on R. prolixus and potentially help it to tolerate higher parasite doses. PMID:27174360

  9. A genomic scale map of genetic diversity in Trypanosoma cruzi

    Ackermann Alejandro A

    2012-12-01

    Full Text Available Abstract Background Trypanosoma cruzi, the causal agent of Chagas Disease, affects more than 16 million people in Latin America. The clinical outcome of the disease results from a complex interplay between environmental factors and the genetic background of both the human host and the parasite. However, knowledge of the genetic diversity of the parasite, is currently limited to a number of highly studied loci. The availability of a number of genomes from different evolutionary lineages of T. cruzi provides an unprecedented opportunity to look at the genetic diversity of the parasite at a genomic scale. Results Using a bioinformatic strategy, we have clustered T. cruzi sequence data available in the public domain and obtained multiple sequence alignments in which one or two alleles from the reference CL-Brener were included. These data covers 4 major evolutionary lineages (DTUs: TcI, TcII, TcIII, and the hybrid TcVI. Using these set of alignments we have identified 288,957 high quality single nucleotide polymorphisms and 1,480 indels. In a reduced re-sequencing study we were able to validate ~ 97% of high-quality SNPs identified in 47 loci. Analysis of how these changes affect encoded protein products showed a 0.77 ratio of synonymous to non-synonymous changes in the T. cruzi genome. We observed 113 changes that introduce or remove a stop codon, some causing significant functional changes, and a number of tri-allelic and tetra-allelic SNPs that could be exploited in strain typing assays. Based on an analysis of the observed nucleotide diversity we show that the T. cruzi genome contains a core set of genes that are under apparent purifying selection. Interestingly, orthologs of known druggable targets show statistically significant lower nucleotide diversity values. Conclusions This study provides the first look at the genetic diversity of T. cruzi at a genomic scale. The analysis covers an estimated ~ 60% of the genetic diversity present in the

  10. Risk Factors and Screening for Trypanosoma cruzi Infection of Dutch Blood Donors

    Slot, Ed; Hogema, Boris M; Molier, Michel; BART, Aldert; Hans L Zaaijer

    2016-01-01

    Background Blood donors unaware of Trypanosoma cruzi infection may donate infectious blood. Risk factors and the presence of T. cruzi antibodies in at-risk Dutch blood donors were studied to assess whether specific blood safety measures are warranted in the Netherlands. Methodology Birth in a country endemic for Chagas disease (CEC), having a mother born in a CEC, or having resided for at least six continuous months in a CEC were considered risk factors for T. cruzi infection. From March thro...

  11. Thrombospondin-1 Interacts with Trypanosoma cruzi Surface Calreticulin to Enhance Cellular Infection

    Johnson, Candice A.; Kleshchenko, Yulia Y.; Ikejiani, Adaeze O.; Udoko, Aniekanabasi N.; Cardenas, Tatiana C.; Pratap, Siddharth; Duquette, Mark A.; Lima, Maria F.; Lawler, Jack; Villalta, Fernando; Nde, Pius N.

    2012-01-01

    Trypanosoma cruzi causes Chagas disease, which is a neglected tropical disease that produces severe pathology and mortality. The mechanisms by which the parasite invades cells are not well elucidated. We recently reported that T. cruzi up-regulates the expression of thrombospondin-1 (TSP-1) to enhance the process of cellular invasion. Here we characterize a novel TSP-1 interaction with T. cruzi that enhances cellular infection. We show that labeled TSP-1 interacts specifically with the surfac...

  12. Genetic clustering of Trypanosoma cruzi I lineage evidenced by intergenic miniexon gene sequencing

    O' Connor, Olivia; Bosseno, Marie-France; Barnabé, Christian; Douzery, E. J. P.; Brenière, Simone Frédérique

    2007-01-01

    American trypanosomiasis or Chagas disease is endemic in Latin America and caused by the flagellate Trypanosoma cruzi, which exhibits broad genetic variation. In various areas, the transmission of Chagas disease is ensured by sylvatic vectors, mainly carrying the evolutionary lineage I of T cruzi. Despite its epidemiological importance, this lineage is poorly studied. Here, we investigated the genetic variability and the phylogenetic relationships within T cruzi I using sequences of the non-t...

  13. Comprehensive proteomic analysis of Trypanosoma cruzi epimastigote cell surface proteins by two complementary methods

    Queiroz, Rayner M L; Charneau, Sébastien; Motta, Flávia N; Santana, Jaime M; Roepstorff, Peter; Ricart, Carlos A O

    2013-01-01

    Trypanosoma cruzi is a protozoan that causes Chagas' disease, a neglected infectious illness that affects millions of people, mostly in Latin America. Here, the cell surface subproteome of the T. cruzi epimastigote life form was characterized. In order to prepare samples enriched in epimastigote...... of the labeled proteins. Both T. cruzi subproteomes were analyzed by LC-MS/MS. The results showed that the methodologies offered comprehensive and complementary information about the parasite's plasma membrane subproteome....

  14. Purification of extracellular and intracellular amastigotes of Trypanosoma cruzi from mammalian host-infected cells

    sprotocols

    2015-01-01

    Authors: Alexandre Marques, Ernesto Nakayasu & Igor Almeida ### Abstract The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, which affects millions of people in Latin America. T. cruzi has a complex life cycle characterized by several developmental forms present in vertebrate and invertebrate hosts. In vertebrate mammalian hosts T. cruzi is found as intracellular amastigotes and bloodstream trypomastigotes. On the other hand, in the intestine of the ...

  15. Previously Unrecognized Vaccine Candidates Control Trypanosoma cruzi Infection and Immunopathology in Mice ▿

    Bhatia, Vandanajay; Garg, Nisha Jain

    2008-01-01

    Trypanosoma cruzi is the etiologic agent of Chagas' disease, a major health problem in Latin America and an emerging infectious disease in the United States. Previously, we screened a T. cruzi sequence database by a computational-bioinformatic approach and identified antigens that exhibited the characteristics of good vaccine candidates. In this study, we tested the vaccine efficacy of three of the putative candidate antigens against T. cruzi infection and disease in a mouse model. C57BL/6 mi...

  16. Environment, interactions between Trypanosoma cruzi and its host, and health Meio-ambiente, interações entre Trypanosoma cruzi e seu hospedeiro e saúde humana

    Teixeira, Antonio R. L.; Clever Gomes; Lozzi, Silene P.; Hecht, Mariana M.; Ana de Cássia Rosa; Pedro S. Monteiro; Ana Carolina Bussacos; Nadjar Nitz; Concepta McManus

    2009-01-01

    An epidemiological chain involving Trypanosoma cruzi is discussed at the environmental level, and in terms of fine molecular interactions in invertebrate and vertebrate hosts dwelling in different ecosystems. This protozoan has a complex, genetically controlled plasticity, which confers adaptation to approximately 40 blood-sucking triatomine species and to over 1,000 mammalian species, fulfilling diverse metabolic requirements in its complex life-cycle. The Tr. cruzi infections are deeply emb...

  17. Beta-interferon inhibits cell infection by Trypanosoma cruzi

    Kierszenbaum, F.; Sonnenfeld, G.

    1984-01-01

    Beta interferon has been shown to inhibit the capacity of bloodstream forms of the flagellate Trypanosoma cruzi, the causative agent of Chagas' disease, to associate with and infect mouse peritoneal macrophages and rat heart myoblasts. The inhibitory effect was abrogated in the presence of specific antibodies to the interferon. Pretreatment of the parasites with interferon reduced their infectivity for untreated host cells, whereas pretreament of either type of host cell did not affect the interaction. The effect of interferon on the trypanosomes was reversible; the extent of the inhibitory effect was significantly reduced afer 20 min, and was undetectable after 60 min when macrophages were used as host cells. For the myoblasts, 60 min elapsed before the inhibitory effect began to subside and 120 min elapsed before it became insignificant or undetectable.

  18. Parasite Genome Projects and the Trypanosoma cruzi Genome Initiative

    Wim Degrave

    1997-11-01

    Full Text Available Since the start of the human genome project, a great number of genome projects on other "model" organism have been initiated, some of them already completed. Several initiatives have also been started on parasite genomes, mainly through support from WHO/TDR, involving North-South and South-South collaborations, and great hopes are vested in that these initiatives will lead to new tools for disease control and prevention, as well as to the establishment of genomic research technology in developing countries. The Trypanosoma cruzi genome project, using the clone CL-Brener as starting point, has made considerable progress through the concerted action of more than 20 laboratories, most of them in the South. A brief overview of the current state of the project is given

  19. Diverse inhibitor chemotypes targeting Trypanosoma cruzi CYP51.

    Shamila S Gunatilleke

    Full Text Available BACKGROUND: Chagas Disease, a WHO- and NIH-designated neglected tropical disease, is endemic in Latin America and an emerging infection in North America and Europe as a result of population moves. Although a major cause of morbidity and mortality due to heart failure, as well as inflicting a heavy economic burden in affected regions, Chagas Disease elicits scant notice from the pharmaceutical industry because of adverse economic incentives. The discovery and development of new routes to chemotherapy for Chagas Disease is a clear priority. METHODOLOGY/PRINCIPAL FINDINGS: The similarity between the membrane sterol requirements of pathogenic fungi and those of the parasitic protozoon Trypanosoma cruzi, the causative agent of Chagas human cardiopathy, has led to repurposing anti-fungal azole inhibitors of sterol 14α-demethylase (CYP51 for the treatment of Chagas Disease. To diversify the therapeutic pipeline of anti-Chagasic drug candidates we exploited an approach that included directly probing the T. cruzi CYP51 active site with a library of synthetic small molecules. Target-based high-throughput screening reduced the library of ∼104,000 small molecules to 185 hits with estimated nanomolar K(D values, while cross-validation against T. cruzi-infected skeletal myoblast cells yielded 57 active hits with EC(50 <10 µM. Two pools of hits partially overlapped. The top hit inhibited T. cruzi with EC(50 of 17 nM and was trypanocidal at 40 nM. CONCLUSIONS/SIGNIFICANCE: The hits are structurally diverse, demonstrating that CYP51 is a rather permissive enzyme target for small molecules. Cheminformatic analysis of the hits suggests that CYP51 pharmacology is similar to that of other cytochromes P450 therapeutic targets, including thromboxane synthase (CYP5, fatty acid ω-hydroxylases (CYP4, 17α-hydroxylase/17,20-lyase (CYP17 and aromatase (CYP19. Surprisingly, strong similarity is suggested to glutaminyl-peptide cyclotransferase, which is unrelated to CYP

  20. Synthesis and Anti-Trypanosoma cruzi Activity of Diaryldiazepines

    Júlio César L. Menezes; Luana Beatriz A. Vaz; Paula Melo de Abreu Vieira; Kátia da Silva Fonseca; Cláudia Martins Carneiro; Jason G. Taylor

    2014-01-01

    Chagas disease is a so-called “neglected disease” and endemic to Latin America. Nifurtimox and benznidazole are drugs that have considerable efficacy in the treatment of the acute phase of the disease but cause many significant side effects. Furthermore, in the Chronic Phase its efficiency is reduced and their therapeutic effectiveness is dependent on the type of T. cruzi strain. For this reason, the present work aims to drive basic research towards the discovery of new chemical entities t...

  1. Vaccination of dogs with Trypanosoma rangeli induces antibodies against Trypanosoma cruzi in a rural area of Córdoba, Argentina

    Basso, Beatriz; Marini, Vanina; Gauna, Diego; Frias, Maria

    2016-01-01

    Dogs play a major role in the domestic cycle of Trypanosoma cruzi, acting as reservoirs. In a previous work we have developed a model of vaccination of dogs in captivity with nonpathogenic Trypanosoma rangeli epimastigotes, resulting in the production of protective antibodies against T. cruzi, with dramatic decrease of parasitaemia upon challenge with 100,000 virulent forms of this parasite. The aim of this work was to evaluate the immunogenicity of this vaccine in dogs living in a rural area. Domestic dogs, free from T. cruziinfection, received three immunisations with fixed T. rangeliepimastigotes. Dogs were not challenged with T. cruzi, but they were left in their environment. This immunisation induced antibodies againstT. cruzi for more than three years in dogs in their natural habitat, while control dogs remained serologically negative. PMID:27074257

  2. The effect of placental subfractions on Trypanosoma cruzi.

    Frank, F; Sartori, M J; Asteggiano, C; Lin, S; de Fabro, S P; Fretes, R E

    2000-10-01

    Five subfractions were collected from six term placentas by mincing and differential centrifugation: homogenate, nuclear, mitochondrial, lysosomal, and supernatant. The effect of each subfraction on Trypanosoma cruzi was assessed by trypan blue exclusion, relative infectivity of mice, and penetration of susceptible cultured VERO cells. Ultrastructural changes in trypomastigotes were identified after high cell mortality was shown by dye exclusion following treatment with lysosomal and supernatant fractions. Trypomastigotes treated with other subfractions or preheated subfractions, those recovered from infected VERO cells, and controls remained unaffected. This was confirmed by the ability of treated trypomastigotes to infect mice or to penetrate susceptible cultured VERO cells. There were a 48% decrease in parasitemia and fewer myocardial lesions in Balb/c mice following treatment with the lysosomal subfraction compared to homogenate and controls. VERO cells were invaded about half as often after lysosomal treatment compared to controls (P < 0. 05); an 11% decrease in cell invasion following homogenate treatment was not significant. Placental lysosomal enzyme activity was unaffected by trypomastigotes. Human placentas contain one or more heat-labile substances in lysosomal and supernatant subfractions which inhibit or injure trypomastigotes of T. cruzi in cell-free systems. PMID:11001862

  3. In vitro effects of citral on Trypanosoma cruzi metacyclogenesis

    Josiane Cardoso

    2010-12-01

    Full Text Available Citral, the main constituent of lemongrass (Cymbopogon citratus essential oil, was added to Trypanosoma cruzi cultures grown in TAU3AAG medium to observe the effect on the epimastigote-to-trypomastigote differentiation process (metacyclogenesis. Our results showed that citral (20 μg/mL did not affect epimastigote viability or inhibit the differentiation process. Concentrations higher than 60 μg/mL, however, led to 100% cell death (both epimastigote and trypomastigote forms. Although epimastigotes incubated with 30 μg/mL citral were viable and able to adhere to the substrate, we observed around 50% inhibition in metacyclogenesis, with a calculated concentration that inhibited metacyclogenesis by 50% after 24 h (IC50/24 h of about 31 μg/mL. Treatment with 30 μg/mL citral did not hinder epimastigote multiplication because epimastigote growth resumed when treated cells were transferred to a drug-free liver infusion tryptose culture medium. Metacyclogenesis was almost totally abolished at 40 μg/mL after 24 h of incubation. Furthermore, the metacyclic trypomastigotes obtained in vitro were similarly susceptible to citral, with an IC50/24 h, concentration that killed 50% of the cells after 24 h, of about 24.5 μg/mL. Therefore, citral appears to be a good candidate as an inhibitory drug for further studies analyzing the T. cruzi metacyclogenesis process.

  4. Trypanosoma cruzi contains two galactokinases; molecular and biochemical characterization.

    Lobo-Rojas, Ángel E; González-Marcano, Eglys B; Valera-Vera, Edward A; Acosta, Héctor R; Quiñones, Wilfredo A; Burchmore, Richard J S; Concepción, Juan L; Cáceres, Ana J

    2016-10-01

    Two different putative galactokinase genes, found in the genome database of Trypanosoma cruzi were cloned and sequenced. Expression of the genes in Escherichia coli resulted for TcGALK-1 in the synthesis of a soluble and active enzyme, and in the case of TcGALK-2 gene a less soluble protein, with predicted molecular masses of 51.9kDa and 51.3kDa, respectively. The Km values determined for the recombinant proteins were for galactose 0.108mM (TcGALK-1) and 0.091mM (TcGALK-2) and for ATP 0.36mM (TcGALK-1) and 0.1mM (TcGALK-2). Substrate inhibition by ATP (Ki 0.414mM) was only observed for TcGALK-2. Gel-filtration chromatography showed that natural TcGALKs and recombinant TcGALK-1 are monomeric. In agreement with the possession of a type-1 peroxisome-targeting signal by both TcGALKs, they were found to be present inside glycosomes using two different methods of subcellular fractionation in conjunction with mass spectrometry. Both genes are expressed in epimastigote and trypomastigote stages since the respective proteins were immunodetected by western blotting. The T. cruzi galactokinases present their highest (52-47%) sequence identity with their counterpart from Leishmania spp., followed by prokaryotic galactokinases such as those from E. coli and Lactococcus lactis (26-23%). In a phylogenetic analysis, the trypanosomatid galactokinases form a separate cluster, showing an affiliation with bacteria. Epimastigotes of T. cruzi can grow in glucose-depleted LIT-medium supplemented with 20mM of galactose, suggesting that this hexose, upon phosphorylation by a TcGALK, could be used in the synthesis of UDP-galactose and also as a possible carbon and energy source. PMID:27312997

  5. Apoptotic CD8 T-lymphocytes disable macrophage-mediated immunity to Trypanosoma cruzi infection.

    Cabral-Piccin, M P; Guillermo, L V C; Vellozo, N S; Filardy, A A; Pereira-Marques, S T; Rigoni, T S; Pereira-Manfro, W F; DosReis, G A; Lopes, M F

    2016-01-01

    Chagas disease is caused by infection with the protozoan Trypanosoma cruzi. CD8 T-lymphocytes help to control infection, but apoptosis of CD8 T cells disrupts immunity and efferocytosis can enhance parasite infection within macrophages. Here, we investigate how apoptosis of activated CD8 T cells affects M1 and M2 macrophage phenotypes. First, we found that CD8 T-lymphocytes and inflammatory monocytes/macrophages infiltrate peritoneum during acute T. cruzi infection. We show that treatment with anti-Fas ligand (FasL) prevents lymphocyte apoptosis, upregulates type-1 responses to parasite antigens, and reduces infection in macrophages cocultured with activated CD8 T cells. Anti-FasL skews mixed M1/M2 macrophage profiles into polarized M1 phenotype, both in vitro and following injection in infected mice. Moreover, inhibition of T-cell apoptosis induces a broad reprogramming of cytokine responses and improves macrophage-mediated immunity to T. cruzi. The results indicate that disposal of apoptotic CD8 T cells increases M2-macrophage differentiation and contributes to parasite persistence. PMID:27195678

  6. Trypanosoma cruzi: evaluation of (-)-cubebin derivatives activity in the messenger RNAs processing.

    Andrade e Silva, Márcio Luís; Cicarelli, Regina Maria Barretto; Pauletti, Patrícia M; Luz, Priscilla Paiva; Rezende, Karen Cristina Souza; Januário, Ana Helena; da Silva, Rosangela; Pereira, Ana Carolina; Bastos, Jairo Kenupp; de Albuquerque, Sérgio; Magalhães, Lizandra Guidi; Cunha, Wilson Roberto

    2011-08-01

    No fully effective treatment has been developed since the discovery of Chagas' disease. Since drug-resistant Trypanosoma cruzi strains are occurring and the current therapy is effective in the acute phase but with various adverse side effects, more studies are needed to characterize the susceptibility of T. cruzi to new drugs. Pre-mRNA maturation in trypanosomatids occurs through a process called trans-splicing, which is unusual RNA processing reaction, and it implies the processing of polycistronic transcription units into individual mRNAs; a short transcript spliced leader (SL RNA) is trans-spliced to the acceptor pre-mRNA, giving origin to the mature mRNA. Cubebin derivatives seem to provide treatments with less collateral effects than benznidazole and showed similar or better trypanocidal activities than benznidazole. Therefore, the cubebin derivatives ((-)-6,6'-dinitrohinokinin (DNH) and (-)-hinokinin (HQ)) interference in the mRNA processing was evaluated using T. cruzi permeable cells (Y and BOL (Bolivia) strains) following by RNase protection reaction. These substances seem to intervene in any step of the RNA transcription, promoting alterations in the RNA synthesis, even though the RNA processing mechanism still occurs. Furthermore, HQ presented better activity against the parasites than DNH, meaning that BOL strain seems to be more resistant than Y. PMID:21327990

  7. A human astrocytoma cell line is highly susceptible to infection with Trypanosoma cruzi

    Juan Camilo Vargas-Zambrano

    2013-04-01

    Full Text Available Astrocytes play a vital role in neuronal protection, homeostasis, vascular interchange and the local immune response. Some viruses and parasites can cross the blood-brain barrier and infect glia. Trypanosoma cruzi, the aetiological agent of Chagas disease, can seriously compromise the central nervous system, mainly in immune-suppressed individuals, but also during the acute phase of the infection. In this report, the infective capacity of T. cruzi in a human astrocyte tumour-derived cell line was studied. Astrocytes exposed to trypomastigotes (1:10 ratio produced intracellular amastigotes and new trypomastigotes emerged by day 4 post-infection (p.i.. At day 6 p.i., 93% of the cells were infected. Using flow cytometry, changes were observed in both the expression of major histocompatibility complex class I and II molecules and the chemokine secretion pattern of astrocytes exposed to the parasite. Blocking the low-density lipoprotein receptor on astrocytes did not reduce parasite intracellular infection. Thus, T. cruzi can infect astrocytes and modulate the immune response during central nervous system infection.

  8. Domestic Pig (Sus scrofa) as an Animal Model for Experimental Trypanosoma cruzi Infection.

    Yauri, Verónica; Castro-Sesquen, Yagahira E; Verastegui, Manuela; Angulo, Noelia; Recuenco, Fernando; Cabello, Ines; Malaga, Edith; Bern, Caryn; Gavidia, Cesar M; Gilman, Robert H

    2016-05-01

    Pigs were infected with a Bolivian strain of Trypanosoma cruzi (genotype I) and evaluated up to 150 days postinoculation (dpi) to determine the use of pigs as an animal model of Chagas disease. Parasitemia was observed in the infected pigs during the acute phase (15-40 dpi). Anti-T. cruzi immunoglobulin M was detected during 15-75 dpi; high levels of anti-T. cruzi immunoglobulin G were detected in all infected pigs from 75 to 150 dpi. Parasitic DNA was observed by western blot (58%, 28/48) and polymerase chain reaction (27%, 13/48) in urine samples, and in the brain (75%, 3/4), spleen (50%, 2/4), and duodenum (25%, 1/4), but no parasitic DNA was found in the heart, colon, and kidney. Parasites were not observed microscopically in tissues samples, but mild inflammation, vasculitis, and congestion was observed in heart, brain, kidney, and spleen. This pig model was useful for the standardization of the urine test because of the higher volume that can be obtained as compared with other small animal models. However, further experiments are required to observe pathological changes characteristic of Chagas disease in humans. PMID:26928841

  9. Aptamer based, non-PCR, non-serological detection of Chagas disease biomarkers in Trypanosoma cruzi infected mice.

    Rana Nagarkatti

    Full Text Available Chagas disease affects about 5 million people across the world. The etiological agent, the intracellular parasite Trypanosoma cruzi (T. cruzi, can be diagnosed using microscopy, serology or PCR based assays. However, each of these methods has their limitations regarding sensitivity and specificity, and thus to complement these existing diagnostic methods, alternate assays need to be developed. It is well documented that several parasite proteins called T. cruzi Excreted Secreted Antigens (TESA, are released into the blood of an infected host. These circulating parasite antigens could thus be used as highly specific biomarkers of T. cruzi infection. In this study, we have demonstrated that, using a SELEx based approach, parasite specific ligands called aptamers, can be used to detect TESA in the plasma of T. cruzi infected mice. An Enzyme Linked Aptamer (ELA assay, similar to ELISA, was developed using biotinylated aptamers to demonstrate that these RNA ligands could interact with parasite targets. Aptamer L44 (Apt-L44 showed significant and specific binding to TESA as well as T. cruzi trypomastigote extract and not to host proteins or proteins of Leishmania donovani, a related trypanosomatid parasite. Our result also demonstrated that the target of Apt-L44 is conserved in three different strains of T. cruzi. In mice infected with T. cruzi, Apt-L44 demonstrated a significantly higher level of binding compared to non-infected mice suggesting that it could detect a biomarker of T. cruzi infection. Additionally, Apt-L44 could detect these circulating biomarkers in both the acute phase, from 7 to 28 days post infection, and in the chronic phase, from 55 to 230 days post infection. Our results show that Apt-L44 could thus be used in a qualitative ELA assay to detect biomarkers of Chagas disease.

  10. Evolution of subpatent parasitaemia in Trypanosoma cruzi chronically infected mice with the help of a cyclophosphamide amplification transfer assay Evolução das parasitemias subpatentes na infecção crônica experimental pelo Trypanosoma cruzi através do ensaio de subinoculação modificado pelo tratamento com ciclofosfamida

    Alvarez, José M.; Ayumi Oshima; Veronica Mozer; Liliane Guimarães; Hércules Menezes

    1991-01-01

    We have evaluated the sensitivity of the classical blood subinoculation method, modified through cyclophosphamide treatment of transferred mice, for the detection of occult parasitaemias in Trypanosoma cruzi chronically infected mice. Besides its simplicity, the method was shown to be highly sensitive for both the "chronic" phase parasites (99% of chronic cases were shown to harbour occult parasitaemias) and for the acute phase parasites (T. cruzi could be detected in 53.8% of animals transfe...

  11. Integrate Study of a Bolivian Population Infected by Trypanosoma cruzi, the Agent of Chagas Disease

    Simone Frédérique Brenière

    2002-04-01

    Full Text Available A cross section of a human population (501 individuals selected at random, and living in a Bolivian community, highly endemic for Chagas disease, was investigated combining together clinical, parasitological and molecular approaches. Conventional serology and polymerase chain reaction (PCR indicated an active transmission of the infection, a high seroprevalence (43.3% ranging from around 12% in 45 years, and a high sensitivity (83.8% and specificity of PCR. Abnormal ECG tracing was predominant in chagasic patients and was already present among individuals younger than 13 years. SAPA (shed acute phase antigen recombinant protein and the synthetic peptide R-13 were used as antigens in ELISA tests. The reactivity of SAPA was strongly associated to Trypanosoma cruzi infection and independent of the age of the patients but was not suitable neither for universal serodiagnosis nor for discrimination of specific phases of Chagas infection. Anti-R-13 response was observed in 27.5% only in chagasic patients. Moreover, anti-R13 reactivity was associated with early infection and not to cardiac pathology. This result questioned previous studies, which considered the anti-R-13 response as a marker of chronic Chagas heart disease. The major clonets 20 and 39 (belonging to Trypanosoma cruzi I and T. cruzi II respectively which circulate in equal proportions in vectors of the studied area, were identified in patients' blood by PCR. Clonet 39 was selected over clonet 20 in the circulation whatever the age of the patient. The only factor related to strain detected in patients' blood, was the anti-R-13 reactivity: 37% of the patients infected by clonet 39 (94 cases had anti-R13 antibodies contrasting with only 6% of the patients without clonet 39 (16 cases.

  12. Trypanosoma cruzi recognition by macrophages and muscle cells: perspectives after a 15-year study

    Tania C. de Araujo-Jorge

    1992-01-01

    Full Text Available Macrophages and muscle cells are the main targets for invasion of Trypanosoma cruzi. Ultrastructural studies of this phenomenon in vitro showed that invasion occurs by endocytosis, with attachment and internalization being mediated by different components capable of recognizing epi-or trypomastigotes (TRY. A parasitophorus vacuole was formed in both cell types, thereafter fusing with lysosomes. Then, the mechanism of T. cruzi invasion of host cells (HC is essentially similar (during a primary infection in the abscence of a specific immune response, regardless of wether the target cell is a professional or a non-professional phagocytic cell. Using sugars, lectins, glycosidases, proteinases and proteinase inhibitors, we observed that the relative balance between exposed sialic acid and galactose/N-acetyl galactosamine (GAL residues on the TRY surface, determines the parasite's capacity to invade HC, and that lectin-mediated phagocytosis with GAL specificity is important for internalization of T. cruzi into macrophages. On the other hand, GAL on the surface to heart muscle cells participate on TRY adhesion. TRY need to process proteolytically both the HC and their own surface, to expose the necessary ligands and receptors that allow binding to, and internalization in the host cell. The diverse range of molecular mechanisms which the parasite could use to invade the host cell may correspond to differences in the available "receptors"on the surface of each specific cell type. Acute phase components, with lectin or proteinase inhibitory activities (a-macroglobulins, may also be involved in T. cruzi-host cell interaction.

  13. Trypanosoma cruzi: antigen-receptor mediated endocytosis of antibody

    Judith Abelha

    1981-06-01

    Full Text Available Trypanomastigote forms of Trypanosoma cruzi were derived from tissue culture and incubated with immune and non-immune human sera. All immune sera showed high titers of specific humoral antibodies of the IgM or the IgG type. Agglutination and swelling of parasites were observed after incubation at 37ºC, but many trypomastigotes remained free-swimming in the sera for two to three days. The quantitiy of immune serum capable of lysing a maximum of 10 x 10 [raised to the power of 6] sensitized red cells was not capable of lysing 4 x 10 [raised to the power of 3] tripomastigotes. Typically, the parasites underwent cyclical changes with the formation of clumps of amastigotes and the appearance of epimastigote forms. Multiplication of the parasites was observed in immune sera. Further, the infectivity of the parasites to susceptible mice was not lost. All sera used produced similar general effects on the growth of the parasite. The antibody bound to T. cruzi appeard to enter cells by antigen-receptor mediated endocytosis. The ferritin-conjugated antibody was internalized and delivered to phagolysosomes where they might be completely degraded to amino-acids. This seemed to be a coupled process by which the immunoglobulin is first bound to specific parasite surface receptor and then rapidly endocytosed by the cell.Formas tripomastigotas de Trypanosoma cruzi derivadas de cultura de tecido foram encubadas com soros humanos imunes e não-imunes.Todos os soros humanos usados tinham títulos elevados de anticorpos das classes IgM ou IgG. Aglutinação e entumescimento dos parasitos eram observados apos encubação a 37ºC mas muitos tripomastigotas permaneceram circulando livremente nos soros por dois a três dias. A quantidade de soro imune capaz de lisar um máximo de 10 x 10 [elevado a 6] hemácias sensibilizadas não foi capaz de lisar 4 x 10 [elevado a 3] tripomastigotas. Tipicamente, os parasitos apresentavam alterações cíclicas com formação de

  14. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

    Lantos, Andrés B; Carlevaro, Giannina; Araoz, Beatriz; Ruiz Diaz, Pablo; Camara, María de Los Milagros; Buscaglia, Carlos A; Bossi, Mariano; Yu, Hai; Chen, Xi; Bertozzi, Carolyn R; Mucci, Juan; Campetella, Oscar

    2016-04-01

    Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form. PMID

  15. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology.

    Andrés B Lantos

    2016-04-01

    Full Text Available Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully

  16. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

    Lantos, Andrés B.; Carlevaro, Giannina; Araoz, Beatriz; Ruiz Diaz, Pablo; Camara, María de los Milagros; Buscaglia, Carlos A.; Bossi, Mariano; Yu, Hai; Chen, Xi; Bertozzi, Carolyn R.; Mucci, Juan; Campetella, Oscar

    2016-01-01

    Trypanosoma cruzi, the flagellate protozoan agent of Chagas disease or American trypanosomiasis, is unable to synthesize sialic acids de novo. Mucins and trans-sialidase (TS) are substrate and enzyme, respectively, of the glycobiological system that scavenges sialic acid from the host in a crucial interplay for T. cruzi life cycle. The acquisition of the sialyl residue allows the parasite to avoid lysis by serum factors and to interact with the host cell. A major drawback to studying the sialylation kinetics and turnover of the trypomastigote glycoconjugates is the difficulty to identify and follow the recently acquired sialyl residues. To tackle this issue, we followed an unnatural sugar approach as bioorthogonal chemical reporters, where the use of azidosialyl residues allowed identifying the acquired sugar. Advanced microscopy techniques, together with biochemical methods, were used to study the trypomastigote membrane from its glycobiological perspective. Main sialyl acceptors were identified as mucins by biochemical procedures and protein markers. Together with determining their shedding and turnover rates, we also report that several membrane proteins, including TS and its substrates, both glycosylphosphatidylinositol-anchored proteins, are separately distributed on parasite surface and contained in different and highly stable membrane microdomains. Notably, labeling for α(1,3)Galactosyl residues only partially colocalize with sialylated mucins, indicating that two species of glycosylated mucins do exist, which are segregated at the parasite surface. Moreover, sialylated mucins were included in lipid-raft-domains, whereas TS molecules are not. The location of the surface-anchored TS resulted too far off as to be capable to sialylate mucins, a role played by the shed TS instead. Phosphatidylinositol-phospholipase-C activity is actually not present in trypomastigotes. Therefore, shedding of TS occurs via microvesicles instead of as a fully soluble form. PMID

  17. American tripanosomiasis: a study on the prevalence of Trypanosoma cruzi and Trypanosoma cruzi-like organisms in wild rodents in San Luis province, Argentina Tripanosomiasis americana: um estudo sobre a prevalência do Trypanosoma cruzi e Trypanosoma cruzi-like em roedores silvestres da provincia de San Luis, Argentina

    Ana María Brigada

    2010-06-01

    Full Text Available INTRODUCTION: Chagas disease is caused by Trypanosoma cruzi. Wild and perianthropic mammals maintain the infection/transmission cycle, both in their natural habitat and in the peridomestic area. The aim of this paper was to present the results from a study on wild rodents in the central and northern regions of San Luis province, Argentina, in order to evaluate the prevalence of this infection. METHODS: Sherman traps were set up in capture areas located between latitudes 32º and 33º S, and longitudes 65º and 66º W. The captured rodents were taxonomically identified and hemoflagellates were isolated. Morphological, biometric and molecular studies and in vitro cultures were performed. Infection of laboratory animals and histological examination of the cardiac muscle and inoculation area were also carried out. Parasites were detected in circulating blood in Calomys musculinus, Graomys griseoflavus, Phyllotis darwini and Akodon molinae. The parasites were identified using biological criteria. Molecular PCR studies were performed on some isolates, which confirmed the characterization of these hemoflagellates as Trypanosoma cruzi. RESULTS AND CONCLUSIONS: Forty-four percent of the 25 isolates were identified as Trypanosoma cruzi, and the remaining 56% as Trypanosoma cruzi-like. These findings provide evidence that wild rats infected with Trypanosoma cruzi and Trypanosoma cruzi-like organisms are important in areas of low endemicity.INTRODUÇÃO: A doença de Chagas é causada pelo Trypanosoma cruzi e os mamíferos periantrópicos e silvestres mantêm o ciclo de infecção/transmissão, tanto no ambiente natural, como no peridomicílio. O objetivo deste trabalho foi mostrar os resultados de um estudo de roedores silvestres do centro e norte da Província de San Luis, Argentina, para avaliar a prevalência da infecção. MÉTODOS: Estabeleceram-se lugares de caça com armadilhas tipo Sherman entre os 32º - 33º de latitude S e 65º - 66º de

  18. Specific antibodies induce apoptosis in Trypanosoma cruzi epimastigotes.

    Fernández-Presas, Ana María; Tato, Patricia; Becker, Ingeborg; Solano, Sandra; Copitin, Natalia; Kopitin, Natalia; Berzunza, Miriam; Willms, Kaethe; Hernández, Joselin; Molinari, José Luis

    2010-05-01

    The susceptibility of Trypanosoma cruzi epimastigotes to lysis by normal or immune sera in a complement-dependent reaction has been reported. Mouse immune sera depleted complement-induced damage in epimastigotes characterized by morphological changes and death. The purpose of this work was to study the mechanism of death in epimastigotes exposed to decomplemented mouse immune serum. Epimastigotes were maintained in RPMI medium. Immune sera were prepared in mice by immunization with whole crude epimastigote extracts. Viable epimastigotes were incubated with decomplemented normal or immune sera at 37 degrees C. By electron microscopy, agglutinated parasites showed characteristic patterns of membrane fusion between two or more parasites; this fusion also produced interdigitation of the subpellicular microtubules. Apoptosis was determined by flow cytometry using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and annexin V assays. Nuclear features were examined by 4'-,6-diamidino-2'-phenylindole diHCI cytochemistry that demonstrated apoptotic nuclear condensation. Caspase activity was also measured. TUNEL results showed that parasites incubated with decomplemented immune sera took up 26% of specific fluorescence as compared to 1.3% in parasites incubated with decomplemented normal sera. The Annexin-V-Fluos staining kit revealed that epimastigotes incubated with decomplemented immune sera exposed phosphatidylserine on the external leaflet of the plasma membrane. The incubation of parasites with immune sera showed caspase 3 activity. We conclude that specific antibodies are able to induce agglutination and apoptosis in epimastigotes, although the pathway is not elucidated. PMID:20237802

  19. Crystal Structure of Triosephosphate Isomerase from Trypanosoma cruzi in Hexane

    Gao, Xiu-Gong; Maldonado, Ernesto; Perez-Montfort, Ruy; Garza-Ramos, Georgina; Tuena de Gomez-Puyou, Marietta; Gomez-Puyou, Armando; Rodriguez-Romero, Adela

    1999-08-01

    To gain insight into the mechanisms of enzyme catalysis in organic solvents, the x-ray structure of some monomeric enzymes in organic solvents was determined. However, it remained to be explored whether the structure of oligomeric proteins is also amenable to such analysis. The field acquired new perspectives when it was proposed that the x-ray structure of enzymes in nonaqueous media could reveal binding sites for organic solvents that in principle could represent the starting point for drug design. Here, a crystal of the dimeric enzyme triosephosphate isomerase from the pathogenic parasite Trypanosoma cruzi was soaked and diffracted in hexane and its structure solved at 2- angstrom resolution. Its overall structure and the dimer interface were not altered by hexane. However, there were differences in the orientation of the side chains of several amino acids, including that of the catalytic Glu-168 in one of the monomers. No hexane molecules were detected in the active site or in the dimer interface. However, three hexane molecules were identified on the surface of the protein at sites, which in the native crystal did not have water molecules. The number of water molecules in the hexane structure was higher than in the native crystal. Two hexanes localized at <4 angstrom from residues that form the dimer interface; they were in close proximity to a site that has been considered a potential target for drug design.

  20. Trypanosoma cruzi. Surface antigens of blood and culture forms

    The surface polypeptides of both cultured and blood forms of Trypanosoma cruzi were iodinated by the glucose oxidase-lactoperoxidase technique. Blood-form trypomastigotes (BFT) isolated form infected mice displayed a major 90,000-Mr component. In contrast, both epimastigotes and trypomastigotes obtained form acellular cultures expressed a smaller 75,000-Mr peptide. Both major surface components were presumably glycoproteins in terms of their binding to concanavalin A-Sepharose 4B. Within a 3-h period, both blood and culture forms synthesized their respective surface glycoproteins (90,000 Mr and 75,000 Mr, respectively in vitro. [/sub 35/S]methionine-labeled surface peptides were immunoprecipitated with immune sera of both human and murine origin. A panel of sera form patients with chronic Chagas' disease and hyperimmunized mice recognized similar surface peptides. These immunogens were the same components as the major iodinated species. The major BFT surface peptide was readily removed by trypsin treatment of the parasites, although the procedure did not affect the 75,000-Mr peptide from the culture forms. Two-dimensional polyacrylamide gel electrophoresis revealed that the 90,000-Mr peptide found on BFT was an acidic protein of isoelectric point (pI) 5.0, whereas, the 75,000-Mr peptide form culture-form trypomastigotes has a pI of 7.2. The 90,000-Mr component is thought to be responsible for the anti-phagocytic properties of the BFT

  1. Trypanosoma cruzi Response to Sterol Biosynthesis Inhibitors: Morphophysiological Alterations Leading to Cell Death

    Kessler, Rafael Luis; Soares, Maurilio José; Probst, Christian Macagnan; Krieger, Marco Aurélio

    2013-01-01

    The protozoan parasite Trypanosoma cruzi displays similarities to fungi in terms of its sterol lipid biosynthesis, as ergosterol and other 24-alkylated sterols are its principal endogenous sterols. The sterol pathway is thus a potential drug target for the treatment of Chagas disease. We describe here a comparative study of the growth inhibition, ultrastructural and physiological changes leading to the death of T. cruzi cells following treatment with the sterol biosynthesis inhibitors (SBIs) ...

  2. First Case of Natural Infection in Pigs: Review of Trypanosoma cruzi Reservoirs in Mexico

    Paz María Salazar-Schettino

    1997-07-01

    Full Text Available An epidemiological research project was performed in the State of Morelos including collection of samples for blood smears and culture, serological tests, and xenodiagnoses from a total of 76 domestic and peridomestic mammals. Two strains of Trypanosoma cruzi were isolated by haemocultures; one from a pig (Sus scrofa, the first case of natural infection reported in Mexico, and the other from a dog (Canis familiaris. This study summarizes current information in Mexico concerning confirmed reservoirs of T. cruzi

  3. Mucin AgC10 from Trypanosoma cruzi Interferes with L-Selectin-Mediated Monocyte Adhesion

    Alcaide, P.; Lim, Y. C.; Luscinskas, F. W.; Fresno, M

    2010-01-01

    The protozoan parasite Trypanosoma cruzi has evolved sophisticated systems to evade the immune response. An important requirement for a productive immune response is recruitment of the appropriate immune cells from the bloodstream to the sites of infection. Here, we show that a mucin expressed and secreted by the metacyclic infective form of T. cruzi, AgC10, is able to interfere with L-selectin-mediated monocyte adhesion. Thus, incubation of U937 monocytic cells stably expressing L-selectin (...

  4. A Key Role for Old Yellow Enzyme in the Metabolism of Drugs by Trypanosoma cruzi

    Kubata, Bruno Kilunga; Kabututu, Zakayi; Nozaki, Tomoyoshi; Munday, Craig J.; Fukuzumi, Shunichi; Ohkubo, Kei; Lazarus, Michael; Maruyama, Toshihiko; Martin, Samuel K; Duszenko, Michael; Urade, Yoshihiro

    2002-01-01

    Trypanosoma cruzi is the etiological agent of Chagas' disease. So far, first choice anti-chagasic drugs in use have been shown to have undesirable side effects in addition to the emergence of parasite resistance and the lack of prospect for vaccine against T. cruzi infection. Thus, the isolation and characterization of molecules essential in parasite metabolism of the anti-chagasic drugs are fundamental for the development of new strategies for rational drug design and/or the improvement of t...

  5. Anti-Trypanosoma cruzi antibody detection in blood donors in the Southern Brazil

    A.B. Araújo; E.E.S. Vianna; M.E.A. Berne

    2008-01-01

    Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State...

  6. Proteome Expression and Carbonylation Changes During Trypanosoma cruzi Infection and Chagas Disease in Rats*

    Wen, Jian-Jun; Garg, Nisha Jain

    2011-01-01

    Inflammation and oxidative stress, elicited by Trypanosoma cruzi infection, are important pathologic events during progressive Chagasic cardiomyopathy. In this study, we infected Sprague-Dawley rats with T. cruzi, and treated with phenyl-α-tert-butylnitrone (PBN-antioxidant) and/or benznidazole (BZ-anti-parasite). We employed two-dimensional gel electrophoresis/mass spectrometry to investigate (a) the plasma proteomic changes associated with infection and disease development, and (b) the bene...

  7. Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll-like receptors.

    Gazzinelli, Ricardo T.; Campos, Marco A

    2004-01-01

    TRYPANOSOMA cruzi is the etiologic agent of Chagas' disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll-like receptors (TLR) 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88), an adapter protein essential for...

  8. Side effects of immunization with liver attenuated Trypanosoma cruzi in mice and rabbits.

    Basombrío, M A; Besuschio, S; Cossio, P M

    1982-01-01

    Immunity against lethal, bloodstream forms of Trypanosoma cruzi was achieved in mice by preinoculation of approximately equal to 10(5) culture epimastigotes of an attenuated T. cruzi strain (TCC). The risks of TCC inoculation in terms of pathogenicity or eventual increase in virulence of TCC progeny were evaluated. No pathogenic parasites could be selected from TCC progeny by either mouse, triatome, or culture passages. Immunizing doses of live TCC did not induce in adult mice alterations res...

  9. Domestic dogs and cats as sources of Trypanosoma cruzi infection in rural northwestern Argentina

    GÜRTLER, R.E.; CECERE, M. C.; LAURICELLA, M.A.; Cardinal, M.V.; KITRON, U.; Cohen, J. E.

    2006-01-01

    The reservoir capacity of domestic cats and dogs for Trypanosoma cruzi infection and the host-feeding patterns of domestic Triatoma infestans were assessed longitudinally in 2 infested rural villages in north-western Argentina. A total of 86 dogs and 38 cats was repeatedly examined for T. cruzi infection by serology and/or xenodiagnosis. The composite prevalence of infection in dogs (60%), but not in cats, increased significantly with age and with the domiciliary density of infected T. infest...

  10. Trypanosoma cruzi Infection in an Indigenous Kariña Community in Eastern Venezuela

    Mariolga Berrizbeitia; Dairene Moreno; Ward, Brian J.; Erika Gómez; Alicia Jorquera; Jessicca Rodríguez; Norys García; Melfran Herrera; Mercedes Marcano; Momar Ndao

    2012-01-01

    We investigated the seroprevalence of Trypanosoma cruzi infection in an indigenous Kariña population in eastern Venezuela. A total of 175 serum samples were collected in the community of Piñantal during February 2009. Interviews targeting socioeconomic and environmental factors associated with the T. cruzi transmission were also conducted. Samples were evaluated using trypomastigote excreted/secreted antigens (TESAs) in an ELISA format. TESA-ELISA positive samples were confirmed by indirect h...

  11. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico

    Sánchez-González, Gilberto; Figueroa-Lara, Alejandro; Elizondo-Cano, Miguel; Wilson, Leslie; Novelo-Garza, Barbara; Valiente-Banuet, Leopoldo; Janine M Ramsey

    2016-01-01

    An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide...

  12. Cost-Effectiveness of Blood Donation Screening for Trypanosoma cruzi in Mexico.

    Gilberto Sánchez-González; Alejandro Figueroa-Lara; Miguel Elizondo-Cano; Leslie Wilson; Barbara Novelo-Garza; Leopoldo Valiente-Banuet; Janine M Ramsey

    2016-01-01

    An estimated 2 million inhabitants are infected with Chagas disease in Mexico, with highest prevalence coinciding with highest demographic density in the southern half of the country. After vector-borne transmission, Trypanosoma cruzi is principally transmitted to humans via blood transfusion. Despite initiation of serological screening of blood donations or donors for T. cruzi since 1990 in most Latin American countries, Mexico only finally included mandatory serological screening nationwide...

  13. Electrocardiographic Abnormalities in Trypanosoma cruzi Seropositive and Seronegative Former Blood Donors

    Ribeiro, Antonio L.; Sabino, Ester C; Marcolino, Milena S.; Salemi, Vera M. C.; Barbara M. Ianni; Fábio Fernandes; Luciano Nastari; André Antunes; Márcia Menezes; Cláudia Di Lorenzo Oliveira; Vandana Sachdev; Carrick, Danielle M.; Michael P Busch; Murphy, Eduard L.

    2013-01-01

    BACKGROUND: Blood donor screening leads to large numbers of new diagnoses of Trypanosoma cruzi infection, with most donors in the asymptomatic chronic indeterminate form. Information on electrocardiogram (ECG) findings in infected blood donors is lacking and may help in counseling and recognizing those with more severe disease. OBJECTIVES: To assess the frequency of ECG abnormalities in T.cruzi seropositive relative to seronegative blood donors, and to recognize ECG abnormalities associated w...

  14. Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model

    César Gómez-Hernández

    2011-12-01

    Full Text Available INTRODUCTION: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. METHODS: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD - (random amplified polymorphic DNA. RESULTS: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6 to 10(7 parasites/mL and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. CONCLUSIONS: The Mexican T. cruzi strains are myotrophic and belong to group TcI.

  15. Trypanosoma cruzi: vertebrate and invertebrate cycles in the same mammal host, the opossum Didelphis marsupialis

    Maria P. Deane

    1984-12-01

    Full Text Available Epimastigotes multiplying extracellularly and metacyclic trypomastigotes, stages that correspond to the cycle of Trypanosoma cruzi in the intestinal lumen of its insect vector, were consistently found in the lumen of the anal glands of opossums Didelphis marsupialis inoculated subcutaneously with infective feces of triatomid bugs.No gambá (Didelphis marsupialis foi observado um ciclo extracelular do Trypanosoma cruzi: o parasita crescia abundantemente no material de secreção acumulado no lumen das glandulas anais de animais criados em cativeiro e infectados por via subcutanea com fezes de triatomineos.

  16. Antibody-dependent cytolysis of Trypanosoma cruzi by polymorphonuclear leucocytes: dependence on the respiratory burst

    Human polymorphonuclear leucocytes (PMN) lysed antibody-coated Trypanosoma cruzi epimastigotes under in vitro conditions. Cytotoxicity mediated by PMN, evaluated by the release of 3H-uridine-labelled RNA from T. cruzi, required specific, anti-T. cruzi antibody for target binding and triggering of the cytotoxic response. Cytotoxicity was negligible in the absence of serum. To determine if the respiratory burst and active oxygen species production could be triggered by contact with antibody-coated T. cruzi epimastigotes, oxygen consumption, superoxide anion and hydrogen peroxide release were measured under conditions of T. cruzi lysis by PMN. All three parameters of activation of the respiratory burst were increased in the presence of antibody-coated T. cruzi epimastigotes. Antibody or T. cruzi, added separately, caused no significant activation. An increase in the O2 consumption was also observed when human PMN were incubated in the presence of T. cruzi trypomastigotes coated with antibody present in the serum of chronic Chagas' disease patients. Electron microscopy examination of PMN exposed to diaminobenzidine and T. cruzi showed the parasites inside the PMN phagosomes and an electron-dense reaction product between the two membranes which reveals the presence of myeloperoxidase and H2O2. The reaction product was blocked by aminotriazole and cyanide. These data indicate that oxygen-radical production by PMN was increased under conditions of T. cruzi cell killing. (author)

  17. Trypanosoma cruzi Differentiates and Multiplies within Chimeric Parasitophorous Vacuoles in Macrophages Coinfected with Leishmania amazonensis.

    Pessoa, Carina Carraro; Ferreira, Éden Ramalho; Bayer-Santos, Ethel; Rabinovitch, Michel; Mortara, Renato Arruda; Real, Fernando

    2016-05-01

    The trypanosomatids Leishmania amazonensis and Trypanosoma cruzi are excellent models for the study of the cell biology of intracellular protozoan infections. After their uptake by mammalian cells, the parasitic protozoan flagellates L. amazonensis and T. cruzi lodge within acidified parasitophorous vacuoles (PVs). However, whereas L. amazonensis develops in spacious, phagolysosome-like PVs that may enclose numerous parasites, T. cruzi is transiently hosted within smaller vacuoles from which it soon escapes to the host cell cytosol. To investigate if parasite-specific vacuoles are required for the survival and differentiation of T. cruzi, we constructed chimeric vacuoles by infection of L. amazonensis amastigote-infected macrophages with T. cruzi epimastigotes (EPIs) or metacyclic trypomastigotes (MTs). These chimeric vacuoles, easily observed by microscopy, allowed the entry and fate of T. cruzi in L. amazonensis PVs to be dynamically recorded by multidimensional imaging of coinfected cells. We found that although T. cruzi EPIs remained motile and conserved their morphology in chimeric vacuoles, T. cruzi MTs differentiated into amastigote-like forms capable of multiplying. These results demonstrate that the large adaptive vacuoles of L. amazonensis are permissive to T. cruzi survival and differentiation and that noninfective EPIs are spared from destruction within the chimeric PVs. We conclude that T. cruzi differentiation can take place in Leishmania-containing vacuoles, suggesting this occurs prior to their escape into the host cell cytosol. PMID:26975994

  18. Structural design, synthesis and pharmacological evaluation of 4-thiazolidinones against Trypanosoma cruzi.

    de Oliveira Filho, Gevanio Bezerra; de Oliveira Cardoso, Marcos Veríssimo; Espíndola, José Wanderlan Pontes; Ferreira, Luiz Felipe Gomes Rebello; de Simone, Carlos Alberto; Ferreira, Rafaela Salgado; Coelho, Pollyanne Lacerda; Meira, Cássio Santana; Magalhaes Moreira, Diogo Rodrigo; Soares, Milena Botelho Pereira; Lima Leite, Ana Cristina

    2015-12-01

    Chagas disease is an infection caused by protozoan Trypanosoma cruzi, which affects approximately 8-10million people worldwide. Benznidazole is the only drug approved for treatment during the acute and asymptomatic chronic phases of Chagas disease; however, it has poor efficacy during the symptomatic chronic phase. Therefore, the development of new pharmaceuticals is needed. Here, we employed the bioisosterism to modify a potent antiparasitic and cruzain-inhibitor aryl thiosemicarbazone (4) into 4-thiazolidinones (7-21). Compounds (7-21) were prepared by using a straightforward synthesis and enabled good to excellent yields. As a chemical elucidation tool, X-ray diffraction of compound (10) revealed the geometry and conformation of this class compounds. The screening against cruzain showed that 4-thiazolidinones were less active than thiosemicarbazone (4). However, the antiparasitic activity in Y strain trypomastigotes and host cell cytotoxicity in J774 macrophages revealed that compounds (10 and 18-21) are stronger and more selective antiparasitic agents than thiosemicarbazone (4). Specifically, compounds (18-20), which carry a phenyl at position N3 of heterocyclic ring, were the most active ones, suggesting that this is a structural determinant for activity. In infected macrophages, compounds (18-20) reduced intracellular amastigotes, whereas Benznidazole did not. In T. cruzi-infected mice treated orally with 100mg/kg of compound (20), a decreased of parasitemia was observed. In conclusion, we demonstrated that the conversation of thiosemicarbazones into 4-thiazolidinones retains pharmacological property while enhances selectivity. PMID:26549870

  19. Coadministration of cruzipain and GM-CSF DNAs, a new immunotherapeutic vaccine against Trypanosoma cruzi infection.

    Cerny, Natacha; Sánchez Alberti, Andrés; Bivona, Augusto E; De Marzi, Mauricio C; Frank, Fernanda M; Cazorla, Silvia I; Malchiodi, Emilio L

    2016-02-01

    Therapeutic vaccine research and development are especially important in Chagas disease considering the characteristics of the chronic infection and the number of people in the Americas living with a parasite infection for decades. We have previously reported the efficacy of attenuated Salmonella enterica (S) carrying plasmid encoding cruzipain (SCz) to protect against Trypanosoma cruzi infection. In the present work we investigated whether Cz DNA vaccine immunotherapy could be effective in controlling an ongoing T. cruzi infection in mice. We here report the intramuscular administration of naked Cz DNA or the oral administration of Salmonella as Cz DNA delivery system as therapeutic vaccines in mice during acute or chronic infection. The coadministration of a plasmid encoding GM-CSF improved vaccine performance, indicating that the stimulation of innate immune cells is needed in the event of an ongoing infection. These therapeutic vaccines were able to address the response to a protective and sustained Th1 biased profile not only against Cz but also against a variety of parasite antigens. The combined therapeutic vaccine during the chronic phase of infection prevents tissue pathology as shown by a reduced level of enzyme activity characteristic of tissue damage and a tissue status compatible with normal tissue. The obtained results suggest that immunotherapy with Cz and GM-CSF DNAs, either alone or in combination with other drug treatments, may represent a promising alternative for Chagas disease therapy. PMID:26312947

  20. NATURAL INFECTION BY Trypanosoma cruzi IN ONE DOG IN CENTRAL WESTERN BRAZIL: A CASE REPORT

    Arleana do Bom Parto Ferreira de Almeida

    2013-07-01

    Full Text Available SUMMARY It is estimated that about 10 million people are infected with Trypanosoma cruzi worldwide, mostly in Latin America and more than 25 million are at risk of acquiring this infection in endemic areas. Dogs are an important reservoir for this pathogen and thus, considered a risk factor for human populations. This report describes one case of Chagas disease in a dog from Cuiabá, Mato Grosso State, Brazil. The diagnosis was obtained by direct examination of trypomastigote forms in blood smears. Amastigotes forms were visualized in microscopy of the bone marrow, lymph nodes, kidneys, liver and brain. The T. cruzi (ZIII infection was confirmed by Polymerase Chain Reaction, and sequencing. The animal presented multisystemic failure and died. Although acute Chagas disease in humans is not reported in Cuiabá, this is the first report of a canine case in this region. This case represents a warning, to health professionals and authorities, to the possibility of transmission of this zoonosis in Cuiabá.

  1. Brazilian Green Propolis: Effects In Vitro and In Vivo on Trypanosoma cruzi

    Kelly Salomão

    2011-01-01

    Full Text Available The composition of a Brazilian green propolis ethanolic extract (Et-Bra and its effect on Trypanosoma cruzi trypomastigotes and other pathogenic microorganisms have already been reported. Here, we further investigated Et-Bra targets in T. cruzi and its effect on experimental infection of mice. The IC50/4 days for inhibition of amastigote proliferation was 8.5 ± 1.8 μg mL−1, with no damage to the host cells. In epimastigotes Et-Bra induced alterations in reservosomes, Golgi complex and mitochondrion. These effects were confirmed by flow cytometry analysis. In trypomastigotes, Et-Bra led to the loss of plasma membrane integrity. The in vitro studies indicate that Et-Bra interferes in the functionality of the plasma membrane in trypomastigotes and of reservosomes and mitochondrion in epimastigotes. Acutely infected mice were treated orally with Et-Bra and the parasitemia, mortality and GPT, GOT, CK and urea levels were monitored. The extract (25–300 mg kg−1 body weight/day for 10 days reduced the parasitemia, although not at significant levels; increased the survival of the animals and did not induce any hepatic, muscular lesion or renal toxicity. Since Et-Bra was not toxic to the animals, it could be assayed in combination with other drugs. Et-Bra could be a potential metacyclogenesis blocker, considering its effect on reservosomes, which are an important energy source during parasite differentiation.

  2. Human Leucocyte Antigen-G (HLA-G) and Its Murine Functional Homolog Qa2 in the Trypanosoma cruzi Infection

    Dias, Fabrício C.; Mendes-Junior, Celso T.; Silva, Maria C.; Tristão, Fabrine S. M.; Dellalibera-Joviliano, Renata; Soares, Edson G.; Menezes, Jean G.; Schmidt, André; Dantas, Roberto O.; Marin-Neto, José A.; Silva, João S.; Donadi, Eduardo A.

    2015-01-01

    Genetic susceptibility factors, parasite strain, and an adequate modulation of the immune system seem to be crucial for disease progression after Trypanosoma cruzi infection. HLA-G and its murine functional homolog Qa2 have well-recognized immunomodulatory properties. We evaluated the HLA-G 3′ untranslated region (3′UTR) polymorphic sites (associated with mRNA stability and target for microRNA binding) and HLA-G tissue expression (heart, colon, and esophagus) in patients presenting Chagas disease, stratified according to the major clinical variants. Further, we investigated the transcriptional levels of Qa2 and other pro- and anti-inflammatory genes in affected mouse tissues during T. cruzi experimental acute and early chronic infection induced by the CL strain. Chagas disease patients exhibited differential HLA-G 3′UTR susceptibility allele/genotype/haplotype patterns, according to the major clinical variant (digestive/cardiac/mixed/indeterminate). HLA-G constitutive expression on cardiac muscle and colonic cells was decreased in Chagasic tissues; however, no difference was observed for Chagasic and non-Chagasic esophagus tissues. The transcriptional levels of Qa2 and other anti and proinflammatory (CTLA-4, PDCD1, IL-10, INF-γ, and NOS-2) genes were induced only during the acute T. cruzi infection in BALB/c and C57BL/6 mice. We present several lines of evidence indicating the role of immunomodulatory genes and molecules in human and experimental T. cruzi infection. PMID:25688175

  3. Human Leucocyte Antigen-G (HLA-G and Its Murine Functional Homolog Qa2 in the Trypanosoma cruzi Infection

    Fabrício C. Dias

    2015-01-01

    Full Text Available Genetic susceptibility factors, parasite strain, and an adequate modulation of the immune system seem to be crucial for disease progression after Trypanosoma cruzi infection. HLA-G and its murine functional homolog Qa2 have well-recognized immunomodulatory properties. We evaluated the HLA-G 3′ untranslated region (3′UTR polymorphic sites (associated with mRNA stability and target for microRNA binding and HLA-G tissue expression (heart, colon, and esophagus in patients presenting Chagas disease, stratified according to the major clinical variants. Further, we investigated the transcriptional levels of Qa2 and other pro- and anti-inflammatory genes in affected mouse tissues during T. cruzi experimental acute and early chronic infection induced by the CL strain. Chagas disease patients exhibited differential HLA-G 3′UTR susceptibility allele/genotype/haplotype patterns, according to the major clinical variant (digestive/cardiac/mixed/indeterminate. HLA-G constitutive expression on cardiac muscle and colonic cells was decreased in Chagasic tissues; however, no difference was observed for Chagasic and non-Chagasic esophagus tissues. The transcriptional levels of Qa2 and other anti and proinflammatory (CTLA-4, PDCD1, IL-10, INF-γ, and NOS-2 genes were induced only during the acute T. cruzi infection in BALB/c and C57BL/6 mice. We present several lines of evidence indicating the role of immunomodulatory genes and molecules in human and experimental T. cruzi infection.

  4. Broad patterns in domestic vector-borne Trypanosoma cruzi transmission dynamics: synanthropic animals and vector control

    Peterson, Jennifer K.; Bartsch, Sarah M.; Lee, Bruce Y.; Dobson, Andrew P.

    2015-01-01

    Background Chagas disease (caused by Trypanosoma cruzi) is the most important neglected tropical disease (NTD) in Latin America, infecting an estimated 5.7 million people in the 21 countries where it is endemic. It is one of the NTDs targeted for control and elimination by the 2020 London Declaration goals, with the first goal being to interrupt intra-domiciliary vector-borne T. cruzi transmission. A key question in domestic T. cruzi transmission is the role that synanthropic animals play in ...

  5. Effects of Infection by Trypanosoma cruzi and Trypanosoma rangeli on the Reproductive Performance of the Vector Rhodnius prolixus

    Fellet, Maria Raquel; Lorenzo, Marcelo Gustavo; Elliot, Simon Luke; Carrasco, David; Guarneri, Alessandra Aparecida

    2014-01-01

    The insect Rhodnius prolixus is responsible for the transmission of Trypanosoma cruzi, which is the etiological agent of Chagas disease in areas of Central and South America. Besides this, it can be infected by other trypanosomes such as Trypanosoma rangeli. The effects of these parasites on vectors are poorly understood and are often controversial so here we focussed on possible negative effects of these parasites on the reproductive performance of R. prolixus, specifically comparing infected and uninfected couples. While T. cruzi infection did not delay pre-oviposition time of infected couples at either temperature tested (25 and 30°C) it did, at 25°C, increase the e-value in the second reproductive cycle, as well as hatching rates. Meanwhile, at 30°C, T. cruzi infection decreased the e-value of insects during the first cycle and also the fertility of older insects. When couples were instead infected with T. rangeli, pre-oviposition time was delayed, while reductions in the e-value and hatching rate were observed in the second and third cycles. We conclude that both T. cruzi and T. rangeli can impair reproductive performance of R. prolixus, although for T. cruzi, this is dependent on rearing temperature and insect age. We discuss these reproductive costs in terms of potential consequences on triatomine behavior and survival. PMID:25136800

  6. Aspects of resistance to experimental infection with Trypanosoma cruzi

    Chagas disease, a zoonosis caused by the protozoan Trypanosoma cruzi, has a wide distribution in Latin America and extends from the southern part of the United States to Argentina. A number of 10 million of infected people is estimated and another 25 million exposed to the risk. Although discovered over a century, Chagas disease is still a serious infection that causes great socioeconomic impact, with no effective treatment at the chronic phase and in which, a lack of scientific knowledge can be observed. The main goal of this work was that obtaining and using consomic strain of mice, the resistance could be investigated. Consomic strains were produced by programmed mating, in which the animals were monitored with DNA polymorphic markers, and one of his chromosomes was replaced by his homologue from another strain. As parental, were used, the inbred strains C57BL/6/J Unib with resistant phenotype (donor) and as receiver, the A/JUnib strain, that has a susceptible phenotype. These models were used to produce five consomic strains: for the chromosomes 7 (CSs7), 11 (CSs11), 14 (CSs14), 17 (CSs17) and 19 (CSs19), described by Passos et al. (2003) as important in controlling infection caused by the Y strain of T. cruzi. In experimental testing, the consomics were inoculated intraperitoneally at doses of 101, 102, 103 and 104 using as control, animals from both parental lines. In all consomics, resistance was higher than that observed in the susceptible parental. In a second protocol, the consomics were mated with scheduled associations and the progenies were challenged with inocula employing increasing doses of trypomastigotes. The resistance observed in this group was also higher than that observed in the parental with susceptible phenotype. The observed results demonstrate that the use of the consomic strains that were produced order to assess the contribution of each chromosome in the resistance, as well as the effects of association between chromosomes are an

  7. Coinfection with Different Trypanosoma cruzi Strains Interferes with the Host Immune Response to Infection

    Rodrigues, Claudiney Melquíades; Valadares, Helder Magno Silva; Francisco, Amanda Fortes; Arantes, Jerusa Marilda; Campos, Camila França; Teixeira-Carvalho, Andréa; Martins-Filho, Olindo Assis; Araujo, Márcio Sobreira Silva; Arantes, Rosa Maria Esteves; Chiari, Egler; Franco, Glória Regina; Machado, Carlos Renato; Pena, Sérgio Danilo Junho; Faria, Ana Maria Caetano; Macedo, Andréa Mara

    2010-01-01

    A century after the discovery of Trypanosoma cruzi in a child living in Lassance, Minas Gerais, Brazil in 1909, many uncertainties remain with respect to factors determining the pathogenesis of Chagas disease (CD). Herein, we simultaneously investigate the contribution of both host and parasite factors during acute phase of infection in BALB/c mice infected with the JG and/or CL Brener T. cruzi strains. JG single infected mice presented reduced parasitemia and heart parasitism, no mortality, levels of pro-inflammatory mediators (TNF-α, CCL2, IL-6 and IFN-γ) similar to those found among naïve animals and no clinical manifestations of disease. On the other hand, CL Brener single infected mice presented higher parasitemia and heart parasitism, as well as an increased systemic release of pro-inflammatory mediators and higher mortality probably due to a toxic shock-like systemic inflammatory response. Interestingly, coinfection with JG and CL Brener strains resulted in intermediate parasitemia, heart parasitism and mortality. This was accompanied by an increase in the systemic release of IL-10 with a parallel increase in the number of MAC-3+ and CD4+ T spleen cells expressing IL-10. Therefore, the endogenous production of IL-10 elicited by coinfection seems to be crucial to counterregulate the potentially lethal effects triggered by systemic release of pro-inflammatory mediators induced by CL Brener single infection. In conclusion, our results suggest that the composition of the infecting parasite population plays a role in the host response to T. cruzi in determining the severity of the disease in experimentally infected BALB/c mice. The combination of JG and CL Brener was able to trigger both protective inflammatory immunity and regulatory immune mechanisms that attenuate damage caused by inflammation and disease severity in BALB/c mice. PMID:20967289

  8. The steady-state transcriptome of the four major life-cycle stages of Trypanosoma cruzi

    Orlando Ron

    2009-08-01

    Full Text Available Abstract Background Chronic chagasic cardiomyopathy is a debilitating and frequently fatal outcome of human infection with the protozoan parasite, Trypanosoma cruzi. Microarray analysis of gene expression during the T. cruzi life-cycle could be a valuable means of identifying drug and vaccine targets based on their appropriate expression patterns, but results from previous microarray studies in T. cruzi and related kinetoplastid parasites have suggested that the transcript abundances of most genes in these organisms do not vary significantly between life-cycle stages. Results In this study, we used whole genome, oligonucleotide microarrays to globally determine the extent to which T. cruzi regulates mRNA relative abundances over the course of its complete life-cycle. In contrast to previous microarray studies in kinetoplastids, we observed that relative transcript abundances for over 50% of the genes detected on the T. cruzi microarrays were significantly regulated during the T. cruzi life-cycle. The significant regulation of 25 of these genes was confirmed by quantitative reverse-transcriptase PCR (qRT-PCR. The T. cruzi transcriptome also mirrored published protein expression data for several functional groups. Among the differentially regulated genes were members of paralog clusters, nearly 10% of which showed divergent expression patterns between cluster members. Conclusion Taken together, these data support the conclusion that transcript abundance is an important level of gene expression regulation in T. cruzi. Thus, microarray analysis is a valuable screening tool for identifying stage-regulated T. cruzi genes and metabolic pathways.

  9. Active transcription and ultrastructural changes during Trypanosoma cruzi metacyclogenesis

    Ludmila R.P. Ferreira

    2008-03-01

    Full Text Available The differentiation of proliferating epimastigote forms of Trypanosoma cruzi , the protozoan parasite that causes Chagas’ disease, into the infective and non-proliferating metacyclic forms can be reproduced in the laboratory by incubating the cells in a chemically-defined medium that mimics the urine of the insect vector. Epimastigotes have a spherical nucleus, a flagellum protruding from the middle of the protozoan cell, and a disk-shaped kinetoplast - an organelle that corresponds to the mitochondrial DNA. Metacyclic trypomastigotes have an elongated shape with the flagellum protruding from the posterior portion of the cell and associated with a spherical kinetoplast. Here we describe the morphological events of this transformation and characterize a novel intermediate stage by three-dimensional reconstruction of electron microscope serial sections. This new intermediate stage is characterized by a kinetoplast compressing an already elongated nucleus, indicating that metacyclogenesis involves active movements of the flagellar structure relative to the cell body. As transcription occurs more intensely in proliferating epimastigotes than in metacyclics, we also examined the presence of RNA polymerase II and measured transcriptional activity during the differentiation process. Both the presence of the enzyme and transcriptional activity remain unchanged during all steps of metacyclogenesis. RNA polymerase II levels and transcriptional activity only decrease after metacyclics are formed. We suggest that transcription is required during the epimastigote-to-metacyclic trypomastigote differentiation process, until the kinetoplast and flagellum reach the posterior position of the parasites in the infective form.A diferenciação de formas epimastigotas (proliferativas do Trypanosoma cruzi, parasita protozoário causador da doença de Chagas, em formas metacíclicas tripomastigotas (infectivas e não proliferativas, pode ser reproduzida em laborat

  10. Trypanosoma cruzi in the chicken model: Chagas-like heart disease in the absence of parasitism

    Teixeira, A.R.L.; Gomes, C.; Nitz, N.; Sousa, A.O.; Alvez, R.M.; Guimaro, M.C.; Cordeiro, C.; Bernal, F.M.; Rosa, A.C.; Hejnar, Jiří; Leonardecz, E.; Hecht, M.M.

    2011-01-01

    Roč. 5, č. 3 (2011), e1000. ISSN 1935-2735 Institutional research plan: CEZ:AV0Z50520514 Keywords : Chagas disease * Trypanosoma cruzi * kDNA minicircles * inbred chicken Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.716, year: 2011

  11. Importation of Hybrid Human-Associated Trypanosoma cruzi Strains of Southern South American Origin, Colombia.

    Messenger, Louisa A; Ramirez, Juan David; Llewellyn, Martin S; Guhl, Felipe; Miles, Michael A

    2016-08-01

    We report the characterization of Trypanosoma cruzi of southern South American origin among humans, domestic vectors, and peridomestic hosts in Colombia using high-resolution nuclear and mitochondrial genotyping. Expanding our understanding of the geographic range of lineage TcVI, which is associated with severe Chagas disease, will help clarify risk of human infection for improved disease control. PMID:27434772

  12. A soluble 3-hydroxy-3-methylglutaryl-CoA reductase in the protozoan Trypanosoma cruzi

    Pena Diaz, Javier; Montalvetti, A; Camacho, A;

    1997-01-01

    We report the isolation and characterization of a genomic clone containing the open reading frame sequence for 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase from Trypanosoma cruzi, the causative agent of Chagas' disease. The protozoan gene encoded for a smaller polypeptide than the rest of the...

  13. Kinetic properties and inhibition of Trypanosoma cruzi 3-hydroxy-3-methylglutaryl CoA reductase

    Hurtado-Guerrrero, Ramón; Pena Diaz, Javier; Montalvetti, Andrea; Ruiz-Pérez, Luis M; González-Pacanowska, Dolores

    2002-01-01

    A detailed kinetic analysis of the recombinant soluble enzyme 3-hydroxy-3-methylglutaryl CoA reductase (HMGR) from Trypanosoma cruzi has been performed. The enzyme catalyzes the normal anabolic reaction and the reductant is NADPH. It also catalyzes the oxidation of mevalonate but at a lower propo...

  14. Aspects of resistance to experimental infection with Trypanosoma cruzi; Aspectos da resistencia a infecao experimental com Trypanosoma cruzi

    Dias, Viviane Liotti

    2010-07-01

    Chagas disease, a zoonosis caused by the protozoan Trypanosoma cruzi, has a wide distribution in Latin America and extends from the southern part of the United States to Argentina. A number of 10 million of infected people is estimated and another 25 million exposed to the risk. Although discovered over a century, Chagas disease is still a serious infection that causes great socioeconomic impact, with no effective treatment at the chronic phase and in which, a lack of scientific knowledge can be observed. The main goal of this work was that obtaining and using consomic strain of mice, the resistance could be investigated. Consomic strains were produced by programmed mating, in which the animals were monitored with DNA polymorphic markers, and one of his chromosomes was replaced by his homologue from another strain. As parental, were used, the inbred strains C57BL/6/J Unib with resistant phenotype (donor) and as receiver, the A/JUnib strain, that has a susceptible phenotype. These models were used to produce five consomic strains: for the chromosomes 7 (CSs7), 11 (CSs11), 14 (CSs14), 17 (CSs17) and 19 (CSs19), described by Passos et al. (2003) as important in controlling infection caused by the Y strain of T. cruzi. In experimental testing, the consomics were inoculated intraperitoneally at doses of 10{sup 1}, 10{sup 2}, 10{sup 3} and 10{sup 4} using as control, animals from both parental lines. In all consomics, resistance was higher than that observed in the susceptible parental. In a second protocol, the consomics were mated with scheduled associations and the progenies were challenged with inocula employing increasing doses of trypomastigotes. The resistance observed in this group was also higher than that observed in the parental with susceptible phenotype. The observed results demonstrate that the use of the consomic strains that were produced order to assess the contribution of each chromosome in the resistance, as well as the effects of association between

  15. Towards an understanding of the interactions of Trypanosoma cruzi and Trypanosoma rangeli within the reduviid insect host Rhodnius prolixus

    Azambuja Patrícia

    2005-01-01

    Full Text Available This review outlines aspects on the developmental stages of Trypanosoma cruzi and Trypanosoma rangeli in the invertebrate host, Rhodnius prolixus. Special attention is given to the interactions of these parasites with gut and hemolymph molecules and the effects of the organization of midgut epithelial cells on the parasite development. The vector insect's permissiveness to T. cruzi, which develops in the vector gut, largely depends on the host nutritional state, the parasite strain and the molecular interactions with trypanolytic compounds, lectins and resident bacteria in the gut. T. rangeli invades the hemocoel and once in the hemolymph, can be recognized and activates the defense system of its insect vector, i.e., the prophenoloxidase system, phagocytosis, hemocyte microaggregation, superoxide and nitric oxide activity and the eicosanoid biosynthesis pathway. Taken together, these findings not only provide a better understanding of the interactions parasite - insect vector, but also offer new insights into basic physiological processes involved in the parasites transmission.

  16. Interactions Between Trypanosoma cruzi the Chagas Disease Parasite and Naturally Infected Wild Mepraia Vectors of Chile.

    Campos-Soto, Ricardo; Ortiz, Sylvia; Cordova, Ivan; Bruneau, Nicole; Botto-Mahan, Carezza; Solari, Aldo

    2016-03-01

    Chagas disease, which ranks among the world's most neglected diseases, is a chronic, systemic, parasitic infection caused by the protozoan Trypanosoma cruzi. Mepraia species are the wild vectors of this parasite in Chile. Host-parasite interactions can occur at several levels, such as co-speciation and ecological host fitting, among others. Thus, we are exploring the interactions between T. cruzi circulating in naturally infected Mepraia species in all areas endemic of Chile. We evaluated T. cruzi infection rates of 27 different haplotypes of the wild Mepraia species and identified their parasite genotypes using minicircle PCR amplification and hybridization tests with genotype-specific DNA probes. Infection rates were lower in northern Chile where Mepraia gajardoi circulates (10-35%); in central Chile, Mepraia spinolai is most abundant, and infection rates varied in space and time (0-55%). T. cruzi discrete typing units (DTUs) TcI, TcII, TcV, and Tc VI were detected. Mixed infections with two or more DTUs are frequently found in highly infected insects. T. cruzi DTUs have distinct, but not exclusive, ecological and epidemiological associations with their hosts. T. cruzi infection rates of M. spinolai were higher than in M. gajardoi, but the presence of mixed infection with more than one T. cruzi DTU was the same. The same T. cruzi DTUs (TcI, TcII, TcV, and TcVI) were found circulating in both vector species, even though TcI was not equally distributed. These results suggest that T. cruzi DTUs are not associated with any of the two genetically related vector species nor with the geographic area. The T. cruzi vectors interactions are discussed in terms of old and recent events. By exploring T. cruzi DTUs present in Mepraia haplotypes and species from northern to central Chile, we open the analysis on these invertebrate host-parasite interactions. PMID:26771702

  17. Transcriptome Remodeling in Trypanosoma cruzi and Human Cells during Intracellular Infection.

    Yuan Li

    2016-04-01

    Full Text Available Intracellular colonization and persistent infection by the kinetoplastid protozoan parasite, Trypanosoma cruzi, underlie the pathogenesis of human Chagas disease. To obtain global insights into the T. cruzi infective process, transcriptome dynamics were simultaneously captured in the parasite and host cells in an infection time course of human fibroblasts. Extensive remodeling of the T. cruzi transcriptome was observed during the early establishment of intracellular infection, coincident with a major developmental transition in the parasite. Contrasting this early response, few additional changes in steady state mRNA levels were detected once mature T. cruzi amastigotes were formed. Our findings suggest that transcriptome remodeling is required to establish a modified template to guide developmental transitions in the parasite, whereas homeostatic functions are regulated independently of transcriptomic changes, similar to that reported in related trypanosomatids. Despite complex mechanisms for regulation of phenotypic expression in T. cruzi, transcriptomic signatures derived from distinct developmental stages mirror known or projected characteristics of T. cruzi biology. Focusing on energy metabolism, we were able to validate predictions forecast in the mRNA expression profiles. We demonstrate measurable differences in the bioenergetic properties of the different mammalian-infective stages of T. cruzi and present additional findings that underscore the importance of mitochondrial electron transport in T. cruzi amastigote growth and survival. Consequences of T. cruzi colonization for the host include dynamic expression of immune response genes and cell cycle regulators with upregulation of host cholesterol and lipid synthesis pathways, which may serve to fuel intracellular T. cruzi growth. Thus, in addition to the biological inferences gained from gene ontology and functional enrichment analysis of differentially expressed genes in parasite and

  18. Transcriptome Remodeling in Trypanosoma cruzi and Human Cells during Intracellular Infection

    Li, Yuan; Shah-Simpson, Sheena; Okrah, Kwame; Belew, A. Trey; Choi, Jungmin; Caradonna, Kacey L.; Padmanabhan, Prasad; Ndegwa, David M.; Temanni, M. Ramzi; Corrada Bravo, Héctor; El-Sayed, Najib M.; Burleigh, Barbara A.

    2016-01-01

    Intracellular colonization and persistent infection by the kinetoplastid protozoan parasite, Trypanosoma cruzi, underlie the pathogenesis of human Chagas disease. To obtain global insights into the T. cruzi infective process, transcriptome dynamics were simultaneously captured in the parasite and host cells in an infection time course of human fibroblasts. Extensive remodeling of the T. cruzi transcriptome was observed during the early establishment of intracellular infection, coincident with a major developmental transition in the parasite. Contrasting this early response, few additional changes in steady state mRNA levels were detected once mature T. cruzi amastigotes were formed. Our findings suggest that transcriptome remodeling is required to establish a modified template to guide developmental transitions in the parasite, whereas homeostatic functions are regulated independently of transcriptomic changes, similar to that reported in related trypanosomatids. Despite complex mechanisms for regulation of phenotypic expression in T. cruzi, transcriptomic signatures derived from distinct developmental stages mirror known or projected characteristics of T. cruzi biology. Focusing on energy metabolism, we were able to validate predictions forecast in the mRNA expression profiles. We demonstrate measurable differences in the bioenergetic properties of the different mammalian-infective stages of T. cruzi and present additional findings that underscore the importance of mitochondrial electron transport in T. cruzi amastigote growth and survival. Consequences of T. cruzi colonization for the host include dynamic expression of immune response genes and cell cycle regulators with upregulation of host cholesterol and lipid synthesis pathways, which may serve to fuel intracellular T. cruzi growth. Thus, in addition to the biological inferences gained from gene ontology and functional enrichment analysis of differentially expressed genes in parasite and host, our

  19. Bats, Trypanosomes, and Triatomines in Ecuador: New Insights into the Diversity, Transmission, and Origins of Trypanosoma cruzi and Chagas Disease

    C. Miguel Pinto; Sofía Ocaña-Mayorga; Tapia, Elicio E.; Lobos, Simón E.; Zurita, Alejandra P.; Fernanda Aguirre-Villacís; Amber MacDonald; Anita G Villacís; Luciana Lima; Teixeira, Marta M. G.; Mario J Grijalva; Perkins, Susan L.

    2015-01-01

    The generalist parasite Trypanosoma cruzi has two phylogenetic lineages associated almost exclusively with bats-Trypanosoma cruzi Tcbat and the subspecies T. c. marinkellei. We present new information on the genetic variation, geographic distribution, host associations, and potential vectors of these lineages. We conducted field surveys of bats and triatomines in southern Ecuador, a country endemic for Chagas disease, and screened for trypanosomes by microscopy and PCR. We identified parasite...

  20. Mechanism of Trypanosoma cruzi Placenta Invasion and Infection: The Use of Human Chorionic Villi Explants

    Ricardo E. Fretes

    2012-01-01

    Full Text Available Congenital Chagas disease, a neglected tropical disease, endemic in Latin America, is associated with premature labor and miscarriage. During vertical transmission the parasite Trypanosoma cruzi (T. cruzi crosses the placental barrier. However, the exact mechanism of the placental infection remains unclear. We review the congenital transmission of T. cruzi, particularly the role of possible local placental factors that contribute to the vertical transmission of the parasite. Additionally, we analyze the different methods available for studying the congenital transmission of the parasite. In that context, the ex vivo infection with T. cruzi trypomastigotes of human placental chorionic villi constitutes an excellent tool for studying parasite infection strategies as well as possible local antiparasitic mechanisms.

  1. Lipid Bodies: Inflammatory Organelles Implicated in Host-Trypanosoma cruzi Interplay during Innate Immune Responses

    Heloisa D'Avila

    2012-01-01

    Full Text Available The flagellated protozoa Trypanosoma cruzi is the causal agent of Chagas' disease, a significant public health issue and still a major cause of morbidity and mortality in Latin America. Acute Chagas' disease elicits a strong inflammatory response. In order to control the parasite multiplication, cells of the monocytic lineage are highly mobilized. Monocyte differentiation leads to the formation of phagocytosing macrophages, which are strongly activated and direct host defense. A distinguishing feature of Chagas' disease-triggered macrophages is the presence of increased numbers of distinct cytoplasmic organelles termed lipid bodies or lipid droplets. These organelles are actively formed in response to the parasite and are sites for synthesis and storage of inflammatory mediators. This review covers current knowledge on lipid bodies elicited by the acute Chagas' disease within inflammatory macrophages and discusses the role of these organelles in inflammation. The increased knowledge of lipid bodies in pathogenic mechanisms of infections may not only contribute to the understanding of pathogen-host interactions but may also identify new targets for intervention.

  2. Identifying four Trypanosoma cruzi I isolate haplotypes from different geographic regions in Colombia.

    Herrera, Claudia; Bargues, M Dolores; Fajardo, Anabella; Montilla, Marleny; Triana, Omar; Vallejo, Gustavo Adolfo; Guhl, Felipe

    2007-07-01

    Trypanosoma cruzi has been classified into the groups T. cruzi I and T. cruzi II. The latter is subdivided into five smaller lineages based on multilocus enzyme electrophoresis and random amplified polymorphic DNA, designated as IIa-IIe, which shows correspondence with rRNA/mini-exon lineages. Twelve previously characterised T. cruzi isolates from different hosts, including humans, Didelphis marsupialis, and triatomines were analysed to establish genetic variability in T. cruzi group T. cruzi I isolates from different geographical regions of Colombia. DNA samples were sequenced based on the mini-exon gene intergenic region. Sequences were analysed using Clustal W, Staden 1.5 and MEGA3 software, and using reported sequences from the GenBank as reference. The genetic distances were analysed using Kimura's two-parameter model. The isolates' joint alignment was of 350bp, and the calculated nucleotide divergence was of 17.5%. The differences consisted of 23 transitions (7.2%), 14 transversions (4.4%) and 19 insertion-deletions (5.9%). The Colombian T cruzi I isolates revealed sufficient genetic variability for us to propose the existence of four haplotypes identified through single nucleotide polymorphism (SNP) and insertion/deletion found in the mini-exon gene's non-transcribed spacer intergenic region. PMID:17287152

  3. Inefficient complement system clearance of Trypanosoma cruzi metacyclic trypomastigotes enables resistant strains to invade eukaryotic cells.

    Igor Cestari

    Full Text Available The complement system is the main arm of the vertebrate innate immune system against pathogen infection. For the protozoan Trypanosoma cruzi, the causative agent of Chagas disease, subverting the complement system and invading the host cells is crucial to succeed in infection. However, little attention has focused on whether the complement system can effectively control T. cruzi infection. To address this question, we decided to analyse: 1 which complement pathways are activated by T. cruzi using strains isolated from different hosts, 2 the capacity of these strains to resist the complement-mediated killing at nearly physiological conditions, and 3 whether the complement system could limit or control T. cruzi invasion of eukaryotic cells. The complement activating molecules C1q, C3, mannan-binding lectin and ficolins bound to all strains analysed; however, C3b and C4b deposition assays revealed that T. cruzi activates mainly the lectin and alternative complement pathways in non-immune human serum. Strikingly, we detected that metacyclic trypomastigotes of some T. cruzi strains were highly susceptible to complement-mediated killing in non-immune serum, while other strains were resistant. Furthermore, the rate of parasite invasion in eukaryotic cells was decreased by non-immune serum. Altogether, these results establish that the complement system recognizes T. cruzi metacyclic trypomastigotes, resulting in killing of susceptible strains. The complement system, therefore, acts as a physiological barrier which resistant strains have to evade for successful host infection.

  4. Epidemiological survey of Trypanosoma cruzi infection in domestic owned cats from the tropical southeast of Mexico.

    Jiménez-Coello, M; Acosta-Viana, K Y; Guzman-Marin, E; Gomez-Rios, A; Ortega-Pacheco, A

    2012-09-01

    American trypanosomiasis is an infectious disease of importance for public health and caused by the protozoa Trypanosoma cruzi mainly transmitted by triatomine bugs. The precise role of cats in the peridomestic transmission of T. cruzi and the mechanism by which cats become infected remain uncertain. The objective of this work was to determine the prevalence of T. cruzi infection in domestic cats from an urban area of tropical Mexico by serological and molecular methods and evaluate associated risk factors. A total of 220 domestic cats from Merida Yucatan, Mexico, were studied. Animals older than 3 months were blood sampled. Serum and DNA were obtained. Specific T. cruzi IgG antibodies were detected using a commercial indirect ELISA with an anti-cat antibody HRP labelled. Positive cases were confirmed by Western blot (WB). Polymerase chain reaction (PCR) was also performed using the primers TC1 and TC2. From the 220 cats, 8.6% had antibodies against T. cruzi using ELISA test and later confirmed by WB. In 75 cats (34%), the sequence of ADNk of T. cruzi was amplified. The bad-regular body condition was the only risk factor associated with PCR positive to T.cruzi (P FIV, FeLV or others). It is necessary to monitor PCR-positive patients and conduct further studies for better understanding of the epidemiology and pathogenesis of Chagas disease in domestic cats. PMID:22958254

  5. Expanding the binding envelope of CYP51 inhibitors targeting Trypanosoma cruzi with 4-aminopyridyl-based sulfonamide derivatives

    Vieira, Debora F.; Choi, Jun Yong; Roush, William R.; Larissa M. Podust

    2014-01-01

    Chagas disease is a chronic infection caused by the protozoan parasite Trypanosoma cruzi, manifested in progressive cardiomyopathy and/or gastrointestinal dysfunction. Therapeutic options to prevent or treat Chagas disease are limited. CYP51, the enzyme key to the biosynthesis of eukaryotic membrane sterols, is a validated drug target in both fungi and T. cruzi. Sulfonamide derivatives of 4-aminopyridyl-based inhibitors of T. cruzi CYP51 (TcCYP51), including the sub-nanomolar compound 3, have...

  6. Analyses of 32 Loci Clarify Phylogenetic Relationships among Trypanosoma cruzi Lineages and Support a Single Hybridization prior to Human Contact

    Flores-López, Carlos A.; Machado, Carlos A.

    2011-01-01

    Background The genetic diversity of Trypanosoma cruzi, the etiological agent of Chagas disease, has been traditionally divided in two major groups, T. cruzi I and II, corresponding to discrete typing units TcI and TcII-VI under a recently proposed nomenclature. The two major groups of T. cruzi seem to differ in important biological characteristics, and are thus thought to represent a natural division relevant for epidemiological studies and development of prophylaxis. To understand the potent...

  7. Seroprevalence of Trypanosoma cruzi Among Eleven Potential Reservoir Species from Six States Across the Southern United States

    Brown, Emily L.; Roellig, Dawn M.; Matthew E. Gompper; Monello, Ryan J.; Wenning, Krista M.; Gabriel, Mourad W.; Yabsley, Michael J.

    2010-01-01

    Trypanosoma cruzi, the causative agent of Chagas' disease, is a substantial public health concern in Latin America. Although rare in humans and domestic animals in the United States, T. cruzi is commonly detected in some wildlife species, most commonly raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana). To increase our understanding of the reservoir host species range and geographic distribution, 11 species of mammals from six states spanning the known range of T. cruzi (Ar...

  8. Detection of Trypanosoma cruzi infection in naturally-infected dogs and cats using serological, parasitological and molecular methods

    ENRIQUEZ, G.F.; Cardinal, M.V.; OROZCO, M.M.; Schijman, A.G.; GÜRTLER, R.E.

    2013-01-01

    Domestic dogs and cats are major domestic reservoir hosts of Trypanosoma cruzi and a risk factor for parasite transmission. In this study we assessed the relative performance of a polymerase chain reaction assay targeted to minicircle DNA (kDNA-PCR) in reference to conventional serological tests, a rapid dipstick test and xenodiagnosis to detect T. cruzi infection in dogs and cats from an endemic rural area in northeastern Argentina. A total of 43 dogs and 13 cats seropositive for T. cruzi by...

  9. The steady-state transcriptome of the four major life-cycle stages of Trypanosoma cruzi

    Orlando Ron; Atwood James; Weatherly D Brent; Minning Todd A; Tarleton Rick L

    2009-01-01

    Abstract Background Chronic chagasic cardiomyopathy is a debilitating and frequently fatal outcome of human infection with the protozoan parasite, Trypanosoma cruzi. Microarray analysis of gene expression during the T. cruzi life-cycle could be a valuable means of identifying drug and vaccine targets based on their appropriate expression patterns, but results from previous microarray studies in T. cruzi and related kinetoplastid parasites have suggested that the transcript abundances of most ...

  10. Trans-sialidase inhibition assay detects Trypanosoma cruzi infection in different wild mammal species.

    Sartor, Paula A; Ceballos, Leonardo A; Orozco, Marcela M; Cardinal, Marta V; Gürtler, Ricardo E; Leguizamón, María S

    2013-08-01

    The detection of Trypanosoma cruzi infection in mammals is crucial for understanding the eco-epidemiological role of the different species involved in parasite transmission cycles. Xenodiagnosis (XD) and hemoculture (HC) are routinely used to detect T. cruzi in wild mammals. Serological methods are much more limited because they require the use of specific antibodies to immunoglobulins of each mammalian species susceptible to T. cruzi. In this study we detected T. cruzi infection by trans-sialidase (TS) inhibition assay (TIA). TIA is based on the antibody neutralization of a recombinant TS that avoids the use of anti-immunoglobulins. TS activity is not detected in the co-endemic protozoan parasites Leishmania spp and T. rangeli. In the current study, serum samples from 158 individuals of nine wild mammalian species, previously tested by XD, were evaluated by TIA. They were collected from two endemic areas in northern Argentina. The overall TIA versus XD co-reactivity was 98.7% (156/158). All 18 samples from XD-positive mammals were TIA-positive (co-positivity, 100%) and co-negativity was 98.5% (138/140). Two XD-negative samples from a marsupial (Didelphis albiventris) and an edentate (Dasypus novemcinctus) were detected by TIA. TIA could be used as a novel tool for serological detection of Trypanosoma cruzi in a wide variety of sylvatic reservoir hosts. PMID:23930975

  11. Biological behaviour in mice of Trypanosoma cruzi isolates from Amazonas and Paraná, Brazil.

    Dos Reis, Daniele; Monteiro, Wuelton Marcelo; Bossolani, Gleison Daion Piovezana; Teston, Ana Paula Margioto; Gomes, Monica Lucia; de Araújo, Silvana Marques; Barbosa, Maria das Graças Vale; de Ornelas Toledo, Max Jean

    2012-04-01

    The biological behaviour of 23 Trypanosoma cruzi isolates in Swiss mice was compared. Nineteen isolates were obtained from patients in the acute phase of Chagas disease (13), sylvatic reservoir hosts (Didelphis marsupialis) (3), and triatomine bugs (Rhodnius robustus) (3) from four regions of the State of Amazonas (AM). Four isolates were obtained from chronic chagasic patients in the State of Paraná (PR): three autochthones, and one allochthone from the State of Minas Gerais. Only one isolate was unable to infect the mice. The AM and PR isolates showed the largest number of significant differences from each other. The former had lower mean values in the pre-patent (5.4 days) and patent (4.6 days) periods (PP), with the parasitaemia (Pmax) reaching a peak of 9.9×10(4) blood trypomastigotes (BT)/mL of blood by the 7th day following inoculation. The AM isolates also had higher positivity to fresh-blood examination (FBE) (84.1%) compared to haemoculture (HC) (58.7%) and polymerase chain reaction (PCR) (33.3%), in addition to higher mortality (2.9%). The PR isolates had higher values for PP (18.5 days) and Pmax (99.9×10(4)BT/mL) as well as higher positivity to FBE (87.2%), HC (100%), and PCR (83.3%). The correlations between the biological behaviour of the T. cruzi isolates and the clinical and epidemiological characteristics of Chagas disease are discussed. PMID:22406038

  12. Serological survey of Leishmania infantum and Trypanosoma cruzi in dogs from urban areas of Brazil and Colombia

    Leishmania infantum and Trypanosoma cruzi are zoonotic parasites that are endemic throughout many parts of Latin America. Infected dogs play an important role in transmission of both parasites to humans. A serological survey of Leishmania and Trypanosoma infection was conducted on 365 dogs from São ...

  13. Efeito inibitório de óleos essenciais sobre Trypanosoma cruzi

    de Azeredo, Camila Maria Oliveira

    2013-01-01

    Resumo: A doença de Chagas, cujo agente etiológico é o protozoário Trypanosoma cruzi, afeta cerca de 10 milhões de pessoas no mundo. O tratamento para a doença é baseado em apenas dois fármacos, o benzonidazol e o nifurtimox, os quais apresentam uma variedade de efeitos colaterais. Devido às dificuldades de tratamento, há urgência na busca por novos fármacos. Uma das alternativas é a procura por produtos naturais que sejam efetivos contra o T. cruzi. Óleos essenciais são misturas complexas de...

  14. P-glycoprotein efflux pump plays an important role in Trypanosoma cruzi drug resistance

    Campos, Mônica Caroline Oliveira; Castro-Pinto, Denise Barçante; Ribeiro, Grazielle Alves; Berredo-Pinho, Márcia Moreira; Gomes, Leonardo Henrique Ferreira; da Silva Bellieny, Myrtes Santos; Goulart, Carla Marins; Echevarria, Áurea; Leon, Leonor Laura

    2013-01-01

    Drug resistance in protozoan parasites has been associated with the P-glycoprotein (Pgp), an energy-dependent efflux pump that transports substances across the membrane. Interestingly, the genes TcPGP1 and TcPGP2 have been described in Trypanosoma cruzi, although the function of these genes has not been fully elucidated. The main goal of this work was to investigate Pgp efflux pump activity and expression in T. cruzi lines submitted to in vitro induced resistance to the compounds 4-N-(2-metho...

  15. Medicinal plants of Chile: evaluation of their anti-Trypanosoma cruzi activity.

    Muñoz, Orlando M; Maya, Juan D; Ferreira, Jorge; Christen, Philippe; San Martin, José; López-Muñoz, Rodrigo; Morello, Antonio; Kemmerling, Ulrike

    2013-01-01

    The extracts of several plants of Central Chile exhibited anti-Trypanosoma cruzi trypomastigotes activity. Most active extracts were those obtained from Podanthus ovatifolius, Berberis microphylla, Kageneckia oblonga, and Drimys winteri. The active extract of Drimys winteri (IC50 51.2 microg/mL) was purified and three drimane sesquiterpenes were obtained: polygodial, drimenol, and isodrimenin. Isodrimenin and drimenol were found to be active against the trypomastigote form of T. cruzi with IC50 values of 27.9 and 25.1 microM, respectively. PMID:23923616

  16. Trypanosoma cruzi, causal agent of Chagas disease: The borderline between wild and domestic cycles in Venezuela.

    Leidi eHerrera

    2014-11-01

    Full Text Available American trypanosomiasis or Chagas disease, caused by Trypanosoma cruzi, occurs between triatomine vectors and mammals, including man. T. cruzi has 150 Ma in America with almost 10 million of infected people today. The overlapping of its wild and domestic ecotopes is increasing. The host-parasite imbrications has been discerned by the study of infection patterns, transmissibility and transmission cycles in natural and laboratory models, through to parasitological and molecular tests. This article describes specific parasite niches, as plant biocenosis or biological corridors between domestic and wild ecotopes and helps distinguish Chagas disease risks and the borderline between wild and domestic transmission cycles, with emphasis on Venezuelan studies.

  17. Cell surface proteome analysis of human-hosted Trypanosoma cruzi life stages

    Queiroz, Rayner M L; Charneau, Sébastien; Bastos, Izabela M D; Santana, Jaime M; Sousa, Marcelo V; Roepstorff, Peter; Ricart, Carlos A O

    2014-01-01

    Chagas' disease is a neglected infectious illness, caused by the protozoan Trypanosoma cruzi. It remains a challenging health issue in Latin America, where it is endemic, and so far there is no immunoprophylatic vaccine or satisfactory chemotherapic treatment for its chronic stage. The present work...... addressed the analysis of the plasma membrane (PM) subproteome from T. cruzi human-hosted life stages, trypomastigote and axenic amastigote, by two complementary PM protein enrichment techniques followed by identification using an LC-MS/MS approach. The results revealed an extensive repertoire of proteins...

  18. Trypanosoma cruzi extracellular amastigotes and host cell signaling: more pieces to the puzzle

    Éden Ramalho Ferreira

    2012-11-01

    Full Text Available Among the different infective stages that Trypanosoma cruzi employs to invade cells, extracellular amastigotes have recently gained attention by our group. This is true primarily because these amastigotes are able to infect cultured cells and animals, establishing a sustainable infective cycle. Extracellular amastigotes are thus an excellent means of adaptation and survival for T. cruzi, whose different infective stages each utilize unique mechanisms for attachment and penetration. Here we discuss some features of host cell invasion by extracellular amastigotes and the associated host cell signaling events that occur as part of the process.

  19. In vitro activity of Rutaceae species against the trypomastigote form of Trypanosoma cruzi.

    Mafezoli, J; Vieira, P C; Fernandes, J B; da Silva, M F; de Albuquerque, S

    2000-11-01

    The activity of crude plant extracts of nine species of Rutaceae against the trypomastigote form of Trypanosoma cruzi was evaluated at 4 mg/ml. Thirty-two crude extracts were tested and eight of them showed significant activity (>80%). The most active extract was obtained from the stems of Pilocarpus spicatus (97.3%). Fractionation of the active crude extracts provided 25 fractions which were tested against the trypomastigote form of T. cruzi at 2 mg/ml. Of these six showed significant activity (>80%). The most active fractions (100%) were obtained from the leaves of Almeidea coerulea (butanol fraction) and Conchocarpus inopinatus (dichloromethane fraction). PMID:11025175

  20. Vitamin C effects in mice experimentally infected with Trypanosoma cruzi QM2 strain

    Alex Silva de Gusmão

    2012-02-01

    Full Text Available INTRODUCTION: To evaluate the efficacy of vitamin C in reducing the consequences generated by the production of free radicals in the acute and chronic phases of Chagas disease, two different doses of ascorbic acid were administered orally to 60 mice infected by Trypanosoma cruzi QM2 strain. METHODS: The animals were divided into six groups: G1, G2, and G3 for the acute phase study, and G'1, G'2, and G'3 for the chronic stage. The groups G1 and G'1 received 8.6x10-4mg/g of vitamin C daily, whereas G2 and G'2 received 7.14x10-3mg/g daily. The other groups, G3 and G'3, were considered placebos and received 10µL of mineral water. RESULTS: The study of the acute phase showed statistically significant differences between G1 and the other groups at various count days of the parasitemia evolution. The multiplying parasite was slower in G1 until the 11th day, but on the 22nd day it had greater parasitemia than in G2 and G3, and from the 36th day on, parasitemia stabilized at higher levels. However, when the histopathology of acute and chronic phases is considered, one does not note significant differences. CONCLUSIONS: The administration of two different doses of vitamin C was not able to protect mice and to contain the oxidative stress caused by free radicals formed by the metabolism of oxygen (reactive oxygen species and nitrogen (reactive nitrogen species.

  1. Is the infectiousness of dogs naturally infected with Trypanosoma cruzi associated with poly-parasitism?

    Enriquez, G F; Garbossa, G; Macchiaverna, N P; Argibay, H D; Bua, J; Gürtler, R E; Cardinal, M V

    2016-06-15

    Interactions among different species of parasites co-infecting the same host could be synergistic or antagonistic. These interactions may modify both the frequency of infected hosts and their infectiousness, and therefore impact on transmission dynamics. This study determined the infectiousness of Trypanosoma cruzi-seropositive dogs (using xenodiagnosis) and their parasite load (quantified by qPCR), and tested the association between both variables and the presence of concomitant endoparasites. A cross-sectional serosurvey conducted in eight rural villages from Pampa del Indio and neighboring municipalities (northeastern Argentina) detected 32 T. cruzi-seropositive dogs out of 217 individuals examined for infection. Both the infectiousness to the vector Triatoma infestans and parasite load of T. cruzi-seropositive dogs examined were heterogeneous. A statistically significant, nine-fold higher mean infectiousness was registered in T. cruzi-seropositive dogs co-infected with Ancylostoma caninum and a trematode than in T. cruzi-seropositive dogs without these infections. The median parasite load of T. cruzi was also significantly higher in dogs co-infected with these helminths. An opposite trend was observed in T. cruzi-seropositive dogs that were serologically positive to Toxoplasma gondii or Neospora caninum relative to dogs seronegative for these parasites. Using multiple logistic regression analysis with random effects, we found a positive and significant association between the infectiousness of T. cruzi-seropositive dogs and co-infections with A. caninum and a trematode. Our results suggest that co-infections may be a modifier of host infectiousness in dogs naturally infected with T. cruzi. PMID:27198799

  2. Serum Cytokines as Biomarkers of Early Trypanosoma cruzi infection by Congenital Exposure.

    Volta, Bibiana J; Bustos, Patricia L; Cardoni, Rita L; De Rissio, Ana M; Laucella, Susana A; Bua, Jacqueline

    2016-06-01

    Trypanosoma cruzi, the causing agent of Chagas disease, leads to an activation of the immune system in congenitally infected infants. In this study, we measured a set of cytokines/chemokines and the levels of parasitemia by quantitative PCR in the circulation of neonates born to T. cruzi-infected mothers to evaluate the predictive value of these mediators as biomarkers of congenital transmission. We conducted a retrospective cohort study of 35 infants with congenital T. cruzi infection, of which 15 and 10 infants had been diagnosed by detection of parasites by microscopy in the first and sixth month after delivery, respectively, and the remaining 10 had been diagnosed by the presence of T. cruzi-specific Abs at 10-12 mo old. Uninfected infants born to either T. cruzi-infected or uninfected mothers were also evaluated as controls. The plasma levels of IL-17A, MCP-1, and monokine induced by IFN-γ were increased in infants congenitally infected with T. cruzi, even before they developed detectable parasitemia or seroconversion. Infants diagnosed between 6 and 12 mo old also showed increased levels of IL-6 and IL-17F at 1 mo of age. Conversely, infants who did not develop congenital T. cruzi infection had higher levels of IFN-γ than infected infants born to uninfected mothers. Monokine induced by IFN-γ, MCP-1, and IFN-γ production induced in T. cruzi-infected infants correlated with parasitemia, whereas the plasma levels of IL-17A, IL-17F, and IL-6 were less parasite load dependent. These findings support the existence of a distinct profile of cytokines and chemokines in the circulation of infants born to T. cruzi-infected mothers, which might predict congenital infection. PMID:27183607

  3. Transmisión vectorial y congénita del Trypanosoma cruzi en Las Lomitas, Formosa Vectorial and congenital transmission of Trypanosoma cruzi in Las Lomitas, Formosa

    Sergio Sosa-Estani; Lucía Dri; Cecilia Touris; Sergio Abalde; Ana Dell'Arciprete; José Braunstein

    2009-01-01

    La enfermedad de Chagas causada por el Trypanosoma cruzi es una causa importante de morbimortalidad en Latino América. El objetivo de este estudio fue describir las tasas de infestación en las viviendas de cuatro comunidades aborígenes de Las Lomitas (Región del Gran Chaco), Formosa, Argentina; la tasa de infección en la población infantil residente en las mismas, en donantes de sangre y en mujeres embarazadas que asistieron al Hospital de Las Lomitas y la tasa de infección congénita de niños...

  4. A high corticosterone/DHEA-s ratio in young rats infected with Trypanosoma cruzi is associated with increased susceptibility

    Ana Rosa Pérez

    2011-06-01

    Full Text Available We have previously established that young male rats are more susceptible to the effects of Trypanosoma cruzi infection than adult rats. To explore underlying age-associated differences in disease outcome, we simultaneously assessed hormone levels and cytokine release throughout the acute infection period in young and adult rats infected with T. cruzi. Young rats were inoculated with 1 x 10(6 and adult rats with 7 x 10(6 blood trypomastigotes, according to their relative body weight. At zero, seven, 14, 21 and 28 days after infection, blood was collected for the determination of gonadal and adrenal hormones, tumor necrosis factor α (TNF-α, interleukin (IL-10 and specific IgM and IgG subtypes. Young animals displayed significantly higher parasitaemia values and an endocrine pattern that was characterised by elevated values in corticosterone (CT and the CT/dehydroepiandrosterone-sulfate ratio, which favours immunosuppression and susceptibility. In contrast, adult male rats were able to restrict the parasite burden, which likely resulted from increased IgG antibody synthesis and oestradiol levels. Adult rats also showed a reduced TNF-α/IL-10 ratio and less tissue damage. We conclude that young animals exhibited increased vulnerability to T. cruzi infection compared with adults and this is associated with an unsuitable immunoendocrine milieu.

  5. Preparation, crystallization and preliminary crystallographic analysis of old yellow enzyme from Trypanosoma cruzi

    Old yellow enzyme from Trypanosoma cruzi, has been crystallized using the hanging-drop vapour-diffusion method. Old yellow enzyme (OYE) is an NADPH oxidoreductase that contains a flavin mononucleotide as a prosthetic group. The OYE from Trypanosoma cruzi, which produces prostaglandin F2α, a potent mediator of various physiological and pathological processes, from prostaglandin H2. The protein was recombinantly expressed and purified from Escherichia coli and was crystallized using the hanging-drop vapour-diffusion method. The crystal belongs to the monoclinic space group P21, with unit-cell parameters a = 56.3, b = 78.8, c = 78.8 Å, β = 93.4° and two molecules per asymmetric unit. The crystals were suitable for X-ray crystallographic studies and diffracted to 1.70 Å resolution. A Patterson search method is in progress using the structure of OYE from Pseudomonas putida as a starting model

  6. Preparation, crystallization and preliminary crystallographic analysis of old yellow enzyme from Trypanosoma cruzi

    Sugiyama, Shigeru [Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan); Tokuoka, Keiji [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Uchiyama, Nahoko [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874 (Japan); Okamoto, Naoki; Okano, Yousuke; Matsumura, Hiroyoshi [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Inaka, Koji [Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan); Urade, Yoshihiro [Department of Molecular Behavioral Biology, Osaka Bioscience Institute, Osaka 565-0874 (Japan); Inoue, Tsuyoshi, E-mail: inouet@chem.eng.osaka-u.ac.jp [Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871 (Japan); Maruwa Foods Co. Ltd, Tsutsui-cho 170-1, Yamatokoriyama, Nara 639-1123 (Japan)

    2007-10-01

    Old yellow enzyme from Trypanosoma cruzi, has been crystallized using the hanging-drop vapour-diffusion method. Old yellow enzyme (OYE) is an NADPH oxidoreductase that contains a flavin mononucleotide as a prosthetic group. The OYE from Trypanosoma cruzi, which produces prostaglandin F{sub 2α}, a potent mediator of various physiological and pathological processes, from prostaglandin H2. The protein was recombinantly expressed and purified from Escherichia coli and was crystallized using the hanging-drop vapour-diffusion method. The crystal belongs to the monoclinic space group P2{sub 1}, with unit-cell parameters a = 56.3, b = 78.8, c = 78.8 Å, β = 93.4° and two molecules per asymmetric unit. The crystals were suitable for X-ray crystallographic studies and diffracted to 1.70 Å resolution. A Patterson search method is in progress using the structure of OYE from Pseudomonas putida as a starting model.

  7. Trypanosoma cruzi Infection in an Indigenous Kariña Community in Eastern Venezuela

    Mariolga Berrizbeitia

    2012-01-01

    Full Text Available We investigated the seroprevalence of Trypanosoma cruzi infection in an indigenous Kariña population in eastern Venezuela. A total of 175 serum samples were collected in the community of Piñantal during February 2009. Interviews targeting socioeconomic and environmental factors associated with the T. cruzi transmission were also conducted. Samples were evaluated using trypomastigote excreted/secreted antigens (TESAs in an ELISA format. TESA-ELISA positive samples were confirmed by indirect haemagglutination (HAI (Wiener. A nonsystematic collection of vectors was also undertaken. T. cruzi seroprevalence was 7.43% according to both assays, and the mean age of infected patients was 48.61±10.40 years (range 34 to 73 years. The vector infection rate was 20.00% (2/10. T. cruzi seropositivity was associated with a history of triatomine bites, the ability to recognize the vector and poor knowledge about Chagas disease, but no associations were found with gender, house type, knowledge of how the disease is transmitted, or the presence of vectors or animals inside dwellings. To our knowledge, this is the first study of the seroprevalence of T. cruzi in an indigenous population in eastern Venezuela. All of the epidemiological variables required for the establishment of active vectorial transmission of T. cruzi were present in this community.

  8. Detection and classification of Trypanosoma cruzi genotypes in animals of an endemic area of Chile

    Blood samples from 200 sylvatic and peridomestic animals from an endemic area of Chile were subjected to PCR amplification of Trypanosoma cruzi minicircle sequences. This method enabled to detect parasite DNA in animals of the species. (Thylamis elegans, Octodon degus, Phyllotis darwini, and Abrothrix olivaceuss) as representatives of sylvatic animals, and Capra hircus as representative of the peridomestic one. Altogether, 51% of the sylvatic and 36% of the peridomestic animals were infected with T.cruzi Amplified DNA products obtained in this study were then studied by Southern analysis with a panel of four radioactive probes prepared from genotyped T.cruzi clones in the endemic areas of Chile and pertaining to T.cruzi lineages I and II. Most of the animal are infected at a rate of 35% with T.cruzi I, however other 85% are infected with T.cruzi II. This method is able to detect mixed infections with two or more different genotypes this figure raise to approximately 40% in this sample. (author)

  9. Studying nanotoxic effects of CdTe quantum dots in Trypanosoma cruzi

    Stahl, C. V.; Almeida, D. B.; de Thomaz, A. A.; Fontes, A.; Menna-Barreto, R. F. S.; Santos-Mallet, J. R.; Cesar, C. L.; Gomes, S. A. O.; Feder, D.

    2010-02-01

    Many studies have been done in order to verify the possible nanotoxicity of quantum dots in some cellular types. Protozoan pathogens as Trypanosoma cruzi, etiologic agent of Chagas1 disease is transmitted to humans either by blood-sucking triatomine vectors, blood transfusion, organs transplantation or congenital transmission. The study of the life cycle, biochemical, genetics, morphology and others aspects of the T. cruzi is very important to better understand the interactions with its hosts and the disease evolution on humans. Quantum dot, nanocrystals, highly luminescent has been used as tool for experiments in in vitro and in vivo T. cruzi life cycle development in real time. We are now investigating the quantum dots toxicity on T. cruzi parasite cells using analytical methods. In vitro experiments were been done in order to test the interference of this nanoparticle on parasite development, morphology and viability (live-death). Ours previous results demonstrated that 72 hours after parasite incubation with 200 μM of CdTe altered the development of T. cruzi and induced cell death by necrosis in a rate of 34%. QDs labeling did not effect: (i) on parasite integrity, at least until 7 days; (ii) parasite cell dividing and (iii) parasite motility at a concentration of 2 μM CdTe. This fact confirms the low level of cytotoxicity of these QDs on this parasite cell. In summary our results is showing T. cruzi QDs labeling could be used for in vivo cellular studies in Chagas disease.

  10. Targeted Reduction in Expression of Trypanosoma cruzi Surface Glycoprotein gp90 Increases Parasite Infectivity

    Málaga, Sergio; Yoshida, Nobuko

    2001-01-01

    A previous study had shown that the expression of gp90, a stage-specific surface glycoprotein of Trypanosoma cruzi metacyclic trypomastigotes, is inversely correlated with the parasite's ability to invade mammalian cells. By using antisense oligonucleotides complementary to a region of the gp90 gene implicated in host cell adhesion, we investigated whether the selective inhibition of gp90 synthesis affected the capacity of metacyclic forms to enter target cells. Parasites were incubated for 2...

  11. Trypanosoma cruzi CYP51 Inhibitor Derived from a Mycobacterium tuberculosis Screen Hit

    Chiung-Kuang Chen; Doyle, Patricia S.; Yermalitskaya, Liudmila V.; Mackey, Zachary B; Kenny K H Ang; McKerrow, James H.; Larissa M. Podust

    2009-01-01

    BACKGROUND: The two front-line drugs for chronic Trypanosoma cruzi infections are limited by adverse side-effects and declining efficacy. One potential new target for Chagas' disease chemotherapy is sterol 14alpha-demethylase (CYP51), a cytochrome P450 enzyme involved in biosynthesis of membrane sterols. METHODOLOGY/PRINCIPAL FINDING: In a screening effort targeting Mycobacterium tuberculosis CYP51 (CYP51(Mt)), we previously identified the N-[4-pyridyl]-formamide moiety as a building block ca...

  12. Identification, characterization and localization of chagasin, a tight-binding cysteine protease inhibitor in Trypanosoma cruzi

    Monteiro, Ana C. S.; Abrahamson, Magnus; Lima, Ana P. C. A.; Vannier-Santos, Marcos A.; Scharfstein, Julio

    2001-01-01

    Lysosomal cysteine proteases from mammalian cells and plants are regulated by endogenous tight-binding inhibitors from the cystatin superfamily. The presence of cystatin-like inhibitors in lower eukaryotes such as protozoan parasites has not yet been demonstrated, although these cells express large quantities of cysteine proteases and may also count on endogenous inhibitors to regulate cellular proteolysis. Trypanosoma cruzi, the causative agent of Chagas heart disease, is a relevant model to...

  13. New scenarios of Trypanosoma cruzi transmission in the Orinoco region of Colombia

    Lina María Rendón; Felipe Guhl; Juan Manuel Cordovez; Diana Erazo

    2015-01-01

    Rhodnius prolixus, a blood-sucking triatomine with domiciliary anthropophilic habits, is the main vector of Chagas disease. The current paradigm of Trypanosoma cruzi transmission in Columbia includes a sylvatic and domiciliary cycle co-existing with domestic and sylvatic populations of reservoirs. The aim of this study is to evaluate the population densities and relative abundance of triatomines and mammals that may be involved in the sylvatic cycle of Chagas disease to clarify the epidemiolo...

  14. Lack of evidence for integration of Trypanosoma cruzi minicircle DNA in South American human genomes

    Flegontova, Olga; Lukeš, Julius; Flegontov, Pavel

    2012-01-01

    Roč. 42, č. 5 (2012), s. 437-441. ISSN 0020-7519 Grant ostatní: GA MŠk(CZ) LM2010005 Institutional support: RVO:60077344 Keywords : Trypanosoma cruzi * Kinetoplast minicircle * Chagas disease * Horizontal gene transfer * Human genome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.637, year: 2012 http://www.sciencedirect.com/science/article/pii/S0020751912000781

  15. Role in host cell invasion of Trypanosoma cruzi-induced cytosolic-free Ca2+ transients

    1994-01-01

    Trypanosoma cruzi enters cells by a unique mechanism, distinct from phagocytosis. Invasion is facilitated by disruption of host cell actin microfilaments, and involves recruitment and fusion of host lysosomes at the site of parasite entry. These findings implied the existence of transmembrane signaling mechanisms triggered by the parasites in the host cells before invasion. Here we show that infective trypomastigotes or their isolated membranes, but not the noninfective epimastigotes, induce ...

  16. Phosphoproteomic analysis of the human pathogen Trypanosoma cruzi at the epimastigote stage

    Nakayasu, Ernesto S.; Gaynor, Matthew R.; Sobreira, Tiago J.P.; ROSS, JEREMY A.; Almeida, Igor C

    2009-01-01

    Trypanosoma cruzi is the etiologic agent of Chagas disease, which affects millions of people in Latin America and has become a public health concern in the United States and areas of Europe. The possibility that kinase inhibitors represent novel anti-parasitic agents is currently being explored. However, fundamental understanding of the cell signaling networks requires the detailed analysis of the involved phosphorylated proteins. Here, we have performed a comprehensive mass spectrometry (MS)...

  17. Food web connections and the transmission cycles of Trypanosoma cruzi and Trypanosoma evansi (Kinetoplastida, Trypanosomatidae) in the Pantanal Region, Brazil.

    Herrera, H M; Rocha, F L; Lisboa, C V; Rademaker, V; Mourão, G M; Jansen, A M

    2011-07-01

    We examined by parasitological tests (hemocultures and buffy coat) infection by Trypanosoma cruzi and T. evansi in blood samples from Leopardus pardalis, Cerdocyon thous and domestic dogs. Besides, 25 T. cruzi isolates previously derived from feral pigs and small wild mammals were here characterized by miniexon gene and demonstrated to be in the TcI genotype. Herein, we make an overall analysis of the transmission cycle of both trypanosome species in the light of the assemblage of data collected over the last seven years. The carnivore Nasua nasua was confirmed to play a major role in the transmission cycles of both T. cruzi and T. evansi since it was the species that had the higher prevalence and higher parasitemias by both flagellate species. In addition, our results show that both trypanosomatid species may be found throughout the Pantanal landscape, in all forest strata, as shown by the infection of carnivore, arboreal and terrestrial scansorial marsupial species in complex and seasonal transmission cycles. We propose that transmission of T. cruzi and T. evansi in the southern Pantanal region takes place via an intricate ecological trophic network involving generalist and specialist mammal species that are linked through a robust food-web connection. PMID:21600622

  18. Structural Insights into Inhibition of Sterol 14[alpha]-Demethylase in the Human Pathogen Trypanosoma cruzi

    Lepesheva, Galina I.; Hargrove, Tatiana Y.; Anderson, Spencer; Kleshchenko, Yuliya; Furtak, Vyacheslav; Wawrzak, Zdzislaw; Villalta, Fernando; Waterman, Michael R. (Vanderbilt); (NWU); (Meharry)

    2010-09-02

    Trypanosoma cruzi causes Chagas disease (American trypanosomiasis), which threatens the lives of millions of people and remains incurable in its chronic stage. The antifungal drug posaconazole that blocks sterol biosynthesis in the parasite is the only compound entering clinical trials for the chronic form of this infection. Crystal structures of the drug target enzyme, Trypanosoma cruzi sterol 14{alpha}-demethylase (CYP51), complexed with posaconazole, another antifungal agent fluconazole and an experimental inhibitor, (R)-4{prime}-chloro-N-(1-(2,4-dichlorophenyl)-2-(1H-imid-azol-1-yl)ethyl)biphenyl-4-carboxamide (VNF), allow prediction of important chemical features that enhance the drug potencies. Combined with comparative analysis of inhibitor binding parameters, influence on the catalytic activity of the trypanosomal enzyme and its human counterpart, and their cellular effects at different stages of the Trypanosoma cruzi life cycle, the structural data provide a molecular background to CYP51 inhibition and azole resistance and enlighten the path for directed design of new, more potent and selective drugs to develop an efficient treatment for Chagas disease.

  19. Genetic characterization of Trypanosoma cruzi natural clones from the state of Paraíba, Brazil

    Christian Barnabé

    2005-05-01

    Full Text Available Eighteen Trypanosoma cruzi stocks from the state of Paraíba, Brazil, isolated from man, wild mammals, and triatomine bugs were studied by multilocus enzyme electrophoresis and random primed amplified polymorphic DNA. Despite the low number of stocks, a notable genetic, genotypic, and phylogenetic diversity was recorded. The presence of the two main phylogenetic subdivisions, T. cruzi I and II, was recorded. The strong linkage disequilibrium observed in the population under survey suggests that T. cruzi undergoes predominant clonal evolution in this area too, although this result should be confirmed by a broader sample. The pattern of clonal variation does not suggests a recent origin by founder effect with a limited number of different genotypes.

  20. Factors associated with Trypanosoma cruzi exposure among domestic canines in Tennessee.

    Rowland, Meghan E; Maloney, Jenny; Cohen, Sara; Yabsley, Michael J; Huang, Junjun; Kranz, Melissa; Green, Alice; Dunn, John R; Carpenter, L Rand; Jones, Timothy F; Moncayo, Abelardo C

    2010-06-01

    Trypanosoma cruzi , the etiologic agent of Chagas' disease, is enzootic in animal populations of the southeastern United States. In the United States, T. cruzi prevalence has been reported for over 20 different wildlife species, and 7 autochthonous human cases have been documented since 1955. Previous canine (Canis familiaris) serosurveys have been limited either by small sample size or confined geographic reporting areas. In this study, we report a seroprevalence of 6.4% among 860 canines from 31 counties and 5 ecoregions throughout Tennessee, using an indirect immunofluorescent assay (IFA). Statistically significant associations between seropositivity and age, weight, and outdoor living were noted. Differences in seropositivity were not seen based on American Kennel Club (AKC) group, sex, habitat, land cover, and ecoregion. Greater attention should be given to possible T. cruzi transmission in Tennessee and veterinarians should consider Chagas' disease as a differential diagnosis with compatible signs. PMID:20557201

  1. In vitro activity of Etanidazole against the protozoan parasite Trypanosoma cruzi

    Patricia B Petray

    2004-03-01

    Full Text Available We investigated the in vitro action of an hydrosoluble 2-nitroimidazole, Etanidazole (EZL, against Trypanosoma cruzi, the etiologic agent of Chagas disease. EZL displayed lethal activity against isolated trypomastigotes as well as amastigotes of T. cruzi (RA strain growing in Vero cells or J774 macrophages, without affecting host cell viability. Although not completely equivalent to Benznidazole (BZL, the reference drug for Chagas chemotherapy, EZL takes advantage in exertingits anti-T. cruzi activity for longer periods without serious toxic side effects, as those recorded in BZL-treated patients. Our present results encourage further experiments to study in depth the trypanocidal properties of this drug already licensed for use in human cancers.

  2. Circulation of Tc Ia discrete type unit Trypanosoma cruzi in Yucatan Mexico.

    Monteón, Victor; Triana-Chávez, Omar; Mejía-Jaramillo, Ana; Pennignton, Pamela; Ramos-Ligonio, Ángel; Acosta, Karla; Lopez, Ruth

    2016-06-01

    The etiologic agent Trypanosoma cruzi (Tc) has been grouped into six discrete type units (DTU I-VI); within DTU-I exists four subgroups defined Ia-Id. In Colombia, the genotype Ia is associated with human infection and domiciliated Rhodnius vector. In the Yucatan Peninsula of Mexico, the main vector involved in T. cruzi transmission is Triatoma dimidiata predominantly via sylvatic and peridomiciliated cycles. In this study, multiple sequence analysis of mini-exon intergenic regions of T. cruzi isolates obtained from T. dimidiata in the Yucatan Peninsula of Mexico revealed they belonged to Tc Ia DTU along with two additional Mexican strains located 1,570 km away from Yucatan. In conclusion Tc Ia circulates in the Yucatan peninsula in T. dimidiata vector and likewise in the northwest region of Mexico. PMID:27413339

  3. Population genetic analysis of Colombian Trypanosoma cruzi isolates revealed by enzyme electrophoretic profiles

    Manuel Ruiz-Garcia

    2001-01-01

    Full Text Available Although Colombia presents an enormous biological diversity, few studies have been conducted on the population genetics of Trypanosoma cruzi. This study was carried out with 23 Colombian stocks of this protozoa analyzed for 13 isoenzymatic loci. The Hardy-Weinberg equilibrium, the genetic diversity and heterogeneity, the genetic relationships and the possible spatial structure of these 23 Colombian stocks of T. cruzi were estimated. The majority of results obtained are in agreement with a clonal population structure. Nevertheless, two aspects expected in a clonal structure were not discovered in the Colombian T. cruzi stocks. There was an absence of given zymodemes over-represented from a geographical point of view and the presumed temporal stabilizing selective phenomena was not observed either in the Colombian stocks sampled several times through the years of the study. Some hypotheses are discussed in order to explain the results found.

  4. Role of Trypanosoma cruzi Trans-sialidase on the Escape from Host Immune Surveillance

    Nardy, Ana F. F. R.; Freire-de-Lima, Celio G.; Pérez, Ana R.; Morrot, Alexandre

    2016-01-01

    Chagas disease is caused by the flagellate protozoan Trypanosoma cruzi, affecting millions of people throughout Latin America. The parasite dampens host immune response causing modifications in diverse lymphoid compartments, including the thymus. T. cruzi trans-sialidase (TS) seems to play a fundamental role in such immunopathological events. This unusual enzyme catalyses the transference of sialic acid molecules from host glycoconjugates to acceptor molecules placed on the parasite surface. TS activity mediates several biological effects leading to the subversion of host immune system, hence favoring both parasite survival and the establishment of chronic infection. This review summarizes current findings on the roles of TS in the immune response during T. cruzi infection. PMID:27047464

  5. Detection of Trypanosoma cruzi DNA within murine cardiac tissue sections by in situ polymerase chain reaction

    Joshua E Lane

    2003-04-01

    Full Text Available The use of in situ techniques to detect DNA and RNA sequences has proven to be an invaluable technique with paraffin-embedded tissue. Advances in non-radioactive detection systems have further made these procedures shorter and safer. We report the detection of Trypanosoma cruzi, the causative agent of Chagas disease, via indirect and direct in situ polymerace chain reaction within paraffin-embedded murine cardiac tissue sections. The presence of three T. cruzi specific DNA sequences were evaluated: a 122 base pair (bp sequence localized within the minicircle network, a 188 bp satellite nuclear repetitive sequence and a 177 bp sequence that codes for a flagellar protein. In situ hybridization alone was sensitive enough to detect all three T. cruzi specific DNA sequences.

  6. Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll-like receptors

    Ricardo T. Gazzinelli

    1992-01-01

    Full Text Available TRYPANOSOMA cruzi is the etiologic agent of Chagas' disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll-like receptors (TLR 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88, an adapter protein essential for the function of TLRs, in determining the parasitemia and mortality rate of mice infected with T. cruzi. We also discuss the implications of these findings in the pathophysiology of Chagas' disease.

  7. JVG9, a benzimidazole derivative, alters the surface and cytoskeleton of Trypanosoma cruzi bloodstream trypomastigotes

    Díaz-Chiguer, Dylan L; Hernández-Luis, Francisco; Nogueda-Torres, Benjamín; Castillo, Rafael; Reynoso-Ducoing, Olivia; Hernández-Campos, Alicia; Ambrosio, Javier R

    2014-01-01

    Trypanosoma cruzi has a particular cytoskeleton that consists of a subpellicular network of microtubules and actin microfilaments. Therefore, it is an excellent target for the development of new anti-parasitic drugs. Benzimidazole 2-carbamates, a class of well-known broad-spectrum anthelmintics, have been shown to inhibit the in vitro growth of many protozoa. Therefore, to find efficient anti-trypanosomal (trypanocidal) drugs, our group has designed and synthesised several benzimidazole derivatives. One, named JVG9 (5-chloro-1H-benzimidazole-2-thiol), has been found to be effective against T. cruzi bloodstream trypomastigotes under both in vitro and in vivo conditions. Here, we present the in vitro effects observed by laser scanning confocal and scanning electron microscopy on T. cruzi trypomastigotes. Changes in the surface and the distribution of the cytoskeletal proteins are consistent with the hypothesis that the trypanocidal activity of JVG9 involves the cytoskeleton as a target. PMID:25317703

  8. Molecular epidemiology of Trypanosoma cruzi and Triatoma dimidiata in costal Ecuador.

    Wong, Yim Yan; Sornosa Macias, Karen Jeniffer; Guale Martínez, Doris; Solorzano, Luis F; Ramirez-Sierra, Maria Jesus; Herrera, Claudia; Dumonteil, Eric

    2016-07-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In Ecuador, Triatoma dimidiata and Rhodnius ecuadoriensis are the main vector species, responsible for over half of the cases of T. cruzi infection in the country. T. dimidiata is believed to have been introduced in Ecuador during colonial times, and its elimination from the country is thus believed to be feasible. We investigated here the molecular ecology of T. dimidiata and T. cruzi in costal Ecuador to further guide control efforts. Analysis of the Internal Transcribed Spacer 2 (ITS-2) of 23 specimens from Progreso, Guayas, unambiguously supported the likely importation of T. dimidiata from Central America to Ecuador. The observation of a very high parasite infection rate (54%) and frequent feeding on humans (3/5) confirmed a continued risk of transmission to humans. All genotyped parasites corresponded to TcI DTU and Trypanosoma rangeli was not detected in T. dimidiata. TcI subgroups corresponded to TcIa (25%), and mixed infections with TcIa and TcId (75%). Further studies should help clarify T. cruzi genetic structure in the country, and the possible impact of the introduction of T. dimidiata on the circulating parasite strains. The elevated risk posed by this species warrants continuing efforts for its control, but its apparent mobility between peridomestic and domestic habitats may favor reinfestation following insecticide spraying. PMID:27079265

  9. Trypanosoma cruzi Polyamine Transporter: Its Role on Parasite Growth and Survival Under Stress Conditions.

    Reigada, Chantal; Sayé, Melisa; Vera, Edward Valera; Balcazar, Darío; Fraccaroli, Laura; Carrillo, Carolina; Miranda, Mariana R; Pereira, Claudio A

    2016-08-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, a major health problem in Latin America. Polyamines are polycationic compounds that play a critical role as regulators of cell growth and differentiation. In contrast with other protozoa, T. cruzi is auxotrophic for polyamines because of its inability to synthesize putrescine due to the lack of both, arginine and ornithine decarboxylase; therefore, the intracellular availability of polyamines depends exclusively on transport processes. In this work, the polyamine transporter TcPAT12 was overexpressed in T. cruzi epimastigotes demonstrating that growth rates at different concentrations of polyamines strongly depend on the regulation of the polyamine transport. In addition, parasites overexpressing TcPAT12 showed a highly increased resistance to hydrogen peroxide and the trypanocidal drugs nifurtimox and benznidazole, which act by oxidative stress and interfering the synthesis of polyamine derivatives, respectively. Finally, the presence of putative polyamine transporters was analyzed in T. cruzi, Trypanosoma brucei, and Leishmania major genomes identifying 3-6 genes in these trypanosomatids. PMID:26983938

  10. Trypanosoma cruzi: strain selection by diferent schedules of mouse passage of an initially mixed infection

    Maria P. Deane

    1984-12-01

    Full Text Available From an initial double infection in mice, established by simultaneous and equivalent inocula of bloodstream forms of strains Y and F of Trypanosoma cruzi, two lines were derived by subinoculations: one (W passaged every week, the other (M every month. Through biological and biochemical methods only the Y strain was identified at the end of the 10th and 16th passages of line W and only the F strain at the 2nd and 4th passages of line M. The results illustrate strain selection through laboratory manipulation of initially mixed populations of T. cruzi.De uma infecção inicialmente dupla em camundongo, estabelecida por inóculo simultaneo e equivalente de formas sanguíneas das cepas Y e F de Trypanosoma cruzi, duas linhagens foram originadas por subinoculações: uma (W passada casa semana, a outra (M cada mês. Por métodos biológicos e bioquímicos apenas a cepa Y foi identificada ao fim a 10a. e 16a. passagens da linhagem W e apenas a cepa F na 2a. e 4a.passagens de linhagem M. Os resultados demonstram a seleção de cepas através de manipulação em laboratorio de populações inicialmente mistas de T. cruzi.

  11. Nitrofuran drugs as common subversive substrates of Trypanosoma cruzi lipoamide dehydrogenase and trypanothione reductase.

    Blumenstiel, K; Schöneck, R; Yardley, V; Croft, S L; Krauth-Siegel, R L

    1999-12-01

    Lipoamide dehydrogenase (LipDH), trypanothione reductase (TR), and glutathione reductase (GR) catalyze the NAD(P)H-dependent reduction of disulfide substrates. TR occurs exclusively in trypanosomatids which lack a GR. Besides their physiological reactions, the flavoenzymes catalyze the single-electron reduction of nitrofurans with the concomitant generation of superoxide anions. Here, we report on the interaction of clinically used antimicrobial nitrofurans with LipDH and TR from Trypanosoma cruzi, the causative agent of Chagas' disease (South American trypanosomiasis), in comparison to mammalian LipDH and GR. The compounds were studied as inhibitors and as subversive substrates of the enzymes. None of the nitrofurans inhibited LipDH, although they did interfere with the disulfide reduction of TR and GR. When the compounds were studied as substrates, T. cruzi LipDH showed a high rate of nitrofuran reduction and was even more efficient than its mammalian counterpart. Several derivatives were also effective subversive substrates of TR, but the respective reaction with human GR was negligible. Nifuroxazide, nifuroxime, and nifurprazine proved to be the most promising derivatives since they were redox-cycled by both T. cruzi LipDH and TR and had pronounced antiparasitic effects in cultures of T. cruzi and Trypanosoma brucei. The results suggest that those nitrofuran derivatives which interact with both parasite flavoenzymes should be revisited as trypanocidal drugs. PMID:10571254

  12. Tigutcystatin, a cysteine protease inhibitor from Triatoma infestans midgut expressed in response to Trypanosoma cruzi

    Highlights: → Tigutcystatin inhibits Trypanosoma cruzi cysteine proteases with high specificity. → Tigutcystatin expression is up-regulated in response to T. cruzi infection. → It is the first cysteine proteases inhibitor characterized from a triatomine insect. -- Abstract: The insect Triatoma infestans is a vector of Trypanosoma cruzi, the etiological agent of Chagas disease. A cDNA library was constructed from T. infestans anterior midgut, and 244 clones were sequenced. Among the EST sequences, an open reading frame (ORF) with homology to a cystatin type 2 precursor was identified. Then, a 288-bp cDNA fragment encoding mature cystatin (lacking signal peptide) named Tigutcystatin was cloned fused to a N-terminal His tag in pET-14b vector, and the protein expressed in Escherichia coli strain Rosetta gami. Tigutcystatin purified and cleaved by thrombin to remove His tag presented molecular mass of 11 kDa and 10,137 Da by SDS-PAGE and MALDI-TOF mass spectrometry, respectively. Purified Tigutcystatin was shown to be a tight inhibitor towards cruzain, a T. cruzi cathepsin L-like enzyme (Ki = 3.29 nM) and human cathepsin L (Ki = 3.78 nM). Tissue specific expression analysis showed that Tigutcystatin was mostly expressed in anterior midgut, although amplification in small intestine was also detected by semi quantitative RT-PCR. qReal time PCR confirmed that Tigutcystatin mRNA is significantly up-regulated in anterior midgut when T. infestans is infected with T. cruzi. Together, these results indicate that Tigutcystatin may be involved in modulation of T. cruzi in intestinal tract by inhibiting parasite cysteine proteases, which represent the virulence factors of this protozoan.

  13. Tigutcystatin, a cysteine protease inhibitor from Triatoma infestans midgut expressed in response to Trypanosoma cruzi

    Buarque, Diego S.; Spindola, Leticia M.N. [Department of Biochemistry, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, 04044-020 Sao Paulo, SP (Brazil); Martins, Rafael M. [Biology of Host Parasite Interactions Unit, Institute Pasteur, 75015 Paris (France); Braz, Gloria R.C. [Department of Biochemistry, Instituto de Quimica, Universidade Federal do Rio de Janeiro, 21941-909 Rio de Janeiro (Brazil); Tanaka, Aparecida S., E-mail: Tanaka.bioq@epm.br [Department of Biochemistry, Universidade Federal de Sao Paulo, Escola Paulista de Medicina, 04044-020 Sao Paulo, SP (Brazil)

    2011-09-23

    Highlights: {yields} Tigutcystatin inhibits Trypanosoma cruzi cysteine proteases with high specificity. {yields} Tigutcystatin expression is up-regulated in response to T. cruzi infection. {yields} It is the first cysteine proteases inhibitor characterized from a triatomine insect. -- Abstract: The insect Triatoma infestans is a vector of Trypanosoma cruzi, the etiological agent of Chagas disease. A cDNA library was constructed from T. infestans anterior midgut, and 244 clones were sequenced. Among the EST sequences, an open reading frame (ORF) with homology to a cystatin type 2 precursor was identified. Then, a 288-bp cDNA fragment encoding mature cystatin (lacking signal peptide) named Tigutcystatin was cloned fused to a N-terminal His tag in pET-14b vector, and the protein expressed in Escherichia coli strain Rosetta gami. Tigutcystatin purified and cleaved by thrombin to remove His tag presented molecular mass of 11 kDa and 10,137 Da by SDS-PAGE and MALDI-TOF mass spectrometry, respectively. Purified Tigutcystatin was shown to be a tight inhibitor towards cruzain, a T. cruzi cathepsin L-like enzyme (K{sub i} = 3.29 nM) and human cathepsin L (K{sub i} = 3.78 nM). Tissue specific expression analysis showed that Tigutcystatin was mostly expressed in anterior midgut, although amplification in small intestine was also detected by semi quantitative RT-PCR. qReal time PCR confirmed that Tigutcystatin mRNA is significantly up-regulated in anterior midgut when T. infestans is infected with T. cruzi. Together, these results indicate that Tigutcystatin may be involved in modulation of T. cruzi in intestinal tract by inhibiting parasite cysteine proteases, which represent the virulence factors of this protozoan.

  14. Risk Factors and Screening for Trypanosoma cruzi Infection of Dutch Blood Donors.

    Ed Slot

    Full Text Available Blood donors unaware of Trypanosoma cruzi infection may donate infectious blood. Risk factors and the presence of T. cruzi antibodies in at-risk Dutch blood donors were studied to assess whether specific blood safety measures are warranted in the Netherlands.Birth in a country endemic for Chagas disease (CEC, having a mother born in a CEC, or having resided for at least six continuous months in a CEC were considered risk factors for T. cruzi infection. From March through September 2013, risk factor questions were asked to all donors who volunteered to donate blood or blood components. Serum samples were collected from donors reporting one or more risk factors, and screened for IgG antibodies to T. cruzi by EIA.Risk factors for T. cruzi infection were reported by 1,426 of 227,278 donors (0.6%. Testing 1,333 at-risk donors, none (0.0%; 95%, CI 0.0-0.4% was seroreactive for IgG antibodies to T. cruzi. A total of 472 donors were born in a CEC; 553 donors reported their mother being born in a CEC; and 1,121 donors reported a long-term stay in a CEC. The vast majority of reported risk factors were related to Suriname and Brazil. Overall, the participants resided for 7,694 years in CECs, which equals 2.8 million overnight stays. Of those, 1.9 million nights were spent in Suriname.Asymptomatic T. cruzi infection appears to be extremely rare among Dutch blood donors. Blood safety interventions to mitigate the risk of T. cruzi transmission by transfusion would be highly cost-ineffective in the Netherlands, and are thus not required.

  15. Inhibition of HIV-1 replication in human monocyte-derived macrophages by parasite Trypanosoma cruzi.

    Guadalupe Andreani

    Full Text Available BACKGROUND: Cells of monocyte/macrophage lineage are one of the major targets of HIV-1 infection and serve as reservoirs for viral persistence in vivo. These cells are also the target of the protozoa Trypanosoma cruzi, the causative agent of Chagas disease, being one of the most important endemic protozoonoses in Latin America. It has been demonstrated in vitro that co-infection with other pathogens can modulate HIV replication. However, no studies at cellular level have suggested an interaction between T. cruzi and HIV-1 to date. METHODOLOGY/PRINCIPAL FINDINGS: By using a fully replicative wild-type virus, our study showed that T. cruzi inhibits HIV-1 antigen production by nearly 100% (p99% being stronger than HIV-T. cruzi (approximately 90% for BaL and approximately 85% for VSV-G infection. In MDM with established HIV-1 infection, T. cruzi significantly inhibited luciferate activity (p<0.01. By quantifying R-U5 and U5-gag transcripts by real time PCR, our study showed the expression of both transcripts significantly diminished in the presence of trypomastigotes (p<0.05. Thus, T. cruzi inhibits viral post-integration steps, early post-entry steps and entry into MDM. Trypomastigotes also caused a approximately 60-70% decrease of surface CCR5 expression on MDM. Multiplication of T. cruzi inside the MDM does not seem to be required for inhibiting HIV-1 replication since soluble factors secreted by trypomastigotes have shown similar effects. Moreover, the major parasite antigen cruzipain, which is secreted by the trypomastigote form, was able to inhibit viral production in MDM over 90% (p<0.01. CONCLUSIONS/SIGNIFICANCE: Our study showed that T. cruzi inhibits HIV-1 replication at several replication stages in macrophages, a major cell target for both pathogens.

  16. Trypanosoma cruzi: in vivo evaluation of iron in skin employing X-ray fluorescence (XRF) in mouse strains that differ in their susceptibility to infection.

    Estevam, Marcelo; Appoloni, Carlos Roberto; Malvezi, Aparecida Donizette; Tatakihara, Vera Lúcia Hideko; Panis, Carolina; Cecchini, Rubens; Rizzo, Luiz Vicente; Pinge-Filho, Phileno

    2012-04-01

    Trypanosoma cruzi, the causative agent of Chagas' disease (CD), is a substantial public health concern in Latin America. Laboratory mice inoculated with T. cruzi have served as important animal models of acute CD. Host hypoferremic responses occur during T. cruzi infection; therefore, it has been hypothesized that T. cruzi requires iron for optimal growth in host cells and, unlike extracellular pathogens, may benefit from host hypoferremic responses. Recent technological improvements of X-ray fluorescence are useful for diagnostics or monitoring in biomedical applications. The goal of our study was to determine whether the iron availabilities in Swiss and C57BL/6 mice differ during the acute phase of T. cruzi infection and whether the availability correlates with oxidative stress in the susceptible and resistant phenotypes identified in these mice. Our results showed that the decrease in iron levels in the skin of resistant infected mice correlated with the increase in oxidative stress associated with anemia and the reduction in parasite burden. PMID:22136203

  17. Repertoire, genealogy and genomic organization of cruzipain and homologous genes in Trypanosoma cruzi, T. cruzi-like and other trypanosome species.

    Luciana Lima

    Full Text Available Trypanosoma cruzi, the agent of Chagas disease, is a complex of genetically diverse isolates highly phylogenetically related to T. cruzi-like species, Trypanosoma cruzi marinkellei and Trypanosoma dionisii, all sharing morphology of blood and culture forms and development within cells. However, they differ in hosts, vectors and pathogenicity: T. cruzi is a human pathogen infective to virtually all mammals whilst the other two species are non-pathogenic and bat restricted. Previous studies suggest that variations in expression levels and genetic diversity of cruzipain, the major isoform of cathepsin L-like (CATL enzymes of T. cruzi, correlate with levels of cellular invasion, differentiation, virulence and pathogenicity of distinct strains. In this study, we compared 80 sequences of genes encoding cruzipain from 25 T. cruzi isolates representative of all discrete typing units (DTUs TcI-TcVI and the new genotype Tcbat and 10 sequences of homologous genes from other species. The catalytic domain repertoires diverged according to DTUs and trypanosome species. Relatively homogeneous sequences are found within and among isolates of the same DTU except TcV and TcVI, which displayed sequences unique or identical to those of TcII and TcIII, supporting their origin from the hybridization between these two DTUs. In network genealogies, sequences from T. cruzi clustered tightly together and closer to T. c. marinkellei than to T. dionisii and largely differed from homologues of T. rangeli and T. b. brucei. Here, analysis of isolates representative of the overall biological and genetic diversity of T. cruzi and closest T. cruzi-like species evidenced DTU- and species-specific polymorphisms corroborating phylogenetic relationships inferred with other genes. Comparison of both phylogenetically close and distant trypanosomes is valuable to understand host-parasite interactions, virulence and pathogenicity. Our findings corroborate cruzipain as valuable target

  18. Quantitative Proteomic and Phosphoproteomic Analysis of Trypanosoma cruzi Amastigogenesis

    Queiroz, Rayner M L; Charneau, Sebastien; Mandacaru, Samuel C;

    2014-01-01

    well-established differentiation protocol to perform a comprehensive quantitative proteomic and phosphoproteomic analysis of the T. cruzi amastigogenesis. Samples from fully differentiated forms and two biologically relevant intermediate time points were Lys-C/trypsin digested, iTRAQ-labeled and...

  19. Triatominae (Hemiptera, Reduviidae in the Pantanal region: association with Trypanosoma cruzi, different habitats and vertebrate hosts

    Filipe Martins Santos

    2015-10-01

    Full Text Available ABSTRACTINTRODUCTION: The transmission cycle of Trypanosoma cruzi in the Brazilian Pantanal region has been studied during the last decade. Although considerable knowledge is available regarding the mammalian hosts infected by T. cruzi in this wetland, no studies have investigated its vectors in this region. This study aimed to investigate the presence of sylvatic triatomine species in different habitats of the Brazilian Pantanal region and to correlate their presence with the occurrences of vertebrate hosts and T. cruzi infection.METHODS: The fieldwork involved passive search by using light traps and Noireau traps and active search by visual inspection. The light traps were placed at five selected points along forested areas for seven nights during each of the nine excursions. At each point where a light trap was set, eight Noireau traps were placed in palm trees and bromeliads.RESULTS: In all, 88 triatomine bugs were collected: two and one individuals from light traps and Noireau traps, respectively; three from peridomestic areas; 23 in coati nests; and 59 in thornbird nests. In this study, active search in microhabitats showed higher efficiency than passive search, since 95% of the triatomine bugs were caught in nests. Further, triatomine bugs were only found to be infected by T. cruzi in coati nests.CONCLUSIONS: Coati nests might act as a point of convergence and dispersion for triatomine bugs and mammal hosts infected by T. cruzi, thereby playing an important role in the sylvatic cycle of T. cruziin the Pantanal region.

  20. Trypanosoma cruzi infection in Didelphis marsupialis in Santa Catarina and Arvoredo Islands, southern Brazil

    Edmundo C Grisard

    2000-12-01

    Full Text Available Between 1984 and 1993 the prevalence of the Trypanosoma cruzi infection in opossums (Didelphis marsupialis was studied in Santa Catarina and Arvoredo Islands, State of Santa Catarina, Brazil. The association of the triatomine bug Panstrongylus megistus with opossums nests and the infection rate of these triatomines by T. cruzi was also studied. Thirteen different locations were studied in Santa Catarina Island (SCI, in which 137 D. marsupialis were collected. Sixty two opossums were collected at the Arvoredo Island (AI, located 12 miles north from SCI. All captured animals were submitted to parasitological examinations that revealed the presence of T. cruzi in 21.9% of the opossums captured in SCI and 45.2% among opossums captured in the AI. The presence of P. megistus was detected in most of the D. marsupialis nests collected in the SCI, however, in the non-inhabited AI only eight triatomines were collected during the whole study. The presence of T. cruzi-infected D. marsupialis associated with P. megistus in human dwellings in the SCI, and the high infection rate of D. marsupilais by T. cruzi in the absence of a high vector density are discussed.

  1. Trypanosoma cruzi infection in Didelphis marsupialis in Santa Catarina and Arvoredo Islands, southern Brazil.

    Grisard, E C; Carvalho-Pinto, C J; Scholz, A F; Toma, H K; Schlemper, B R; Steindel, M

    2000-01-01

    Between 1984 and 1993 the prevalence of the Trypanosoma cruzi infection in opossums (Didelphis marsupialis) was studied in Santa Catarina and Arvoredo Islands, State of Santa Catarina, Brazil. The association of the triatomine bug Panstrongylus megistus with opossums nests and the infection rate of these triatomines by T. cruzi was also studied. Thirteen different locations were studied in Santa Catarina Island (SCI), in which 137 D. marsupialis were collected. Sixty two opossums were collected at the Arvoredo Island (AI), located 12 miles north from SCI. All captured animals were submitted to parasitological examinations that revealed the presence of T. cruzi in 21.9% of the opossums captured in SCI and 45.2% among opossums captured in the AI. The presence of P. megistus was detected in most of the D. marsupialis nests collected in the SCI, however, in the non-inhabited AI only eight triatomines were collected during the whole study. The presence of T. cruzi-infected D. marsupialis associated with P. megistus in human dwellings in the SCI, and the high infection rate of D. marsupilais by T. cruzi in the absence of a high vector density are discussed. PMID:11080763

  2. Risk factors associated with Trypanosoma cruzi exposure in domestic dogs from a rural community in Panama

    Saldaña, Azael; Calzada, José E; Pineda, Vanessa; Perea, Milixa; Rigg, Chystrie; González, Kadir; Santamaria, Ana Maria; Gottdenker, Nicole L; Chaves, Luis F

    2015-01-01

    Chagas disease, caused by Trypanosoma cruzi infection, is a zoonosis of humans, wild and domestic mammals, including dogs. In Panama, the main T. cruzi vector is hodnius pallescens, a triatomine bug whose main natural habitat is the royal palm, Attalea butyracea. In this paper, we present results from three T. cruzi serological tests (immunochromatographic dipstick, indirect immunofluorescence and ELISA) performed in 51 dogs from 24 houses in Trinidad de Las Minas, western Panama. We found that nine dogs were seropositive (17.6% prevalence). Dogs were 1.6 times more likely to become T. cruzi seropositive with each year of age and 11.6 times if royal palms where present in the peridomiciliary area of the dog's household or its two nearest neighbours. Mouse-baited-adhesive traps were employed to evaluate 12 peridomestic royal palms. All palms were found infested with R. pallescens with an average of 25.50 triatomines captured per palm. Of 35 adult bugs analysed, 88.6% showed protozoa flagellates in their intestinal contents. In addition, dogs were five times more likely to be infected by the presence of an additional domestic animal species in the dog's peridomiciliary environment. Our results suggest that interventions focused on royal palms might reduce the exposure to T. cruzi infection. PMID:26560985

  3. Synthesis and characterization of potent inhibitors of Trypanosoma cruzi dihydrofolate reductase

    Schormann, Norbert; Velu, Sadanandan E.; Murugesan, Srinivasan; Senkovich, Olga; Walker, Kiera; Chenna, Bala C.; Shinkre, Bidhan; Desai, Amar; Chattopadhyay, Debasish (UAB)

    2010-09-17

    Dihydrofolate reductase (DHFR) of the parasite Trypanosoma cruzi (T. cruzi) is a potential target for developing drugs to treat Chagas disease. We have undertaken a detailed structure-activity study of this enzyme. We report here synthesis and characterization of six potent inhibitors of the parasitic enzyme. Inhibitory activity of each compound was determined against T. cruzi and human DHFR. One of these compounds, ethyl 4-(5-[(2,4-diamino-6-quinazolinyl)methyl]amino-2-methoxyphenoxy)butanoate (6b) was co-crystallized with the bifunctional dihydrofolate reductase-thymidylate synthase enzyme of T. cruzi and the crystal structure of the ternary enzyme:cofactor:inhibitor complex was determined. Molecular docking was used to analyze the potential interactions of all inhibitors with T. cruzi DHFR and human DHFR. Inhibitory activities of these compounds are discussed in the light of enzyme-ligand interactions. Binding affinities of each inhibitor for the respective enzymes were calculated based on the experimental or docked binding mode. An estimated 60-70% of the total binding energy is contributed by the 2,4-diaminoquinazoline scaffold.

  4. Activity of P536, a UDP-glucose analog, against Trypanosoma cruzi

    P536, a UDP-glucose analog which was previously described as an antiviral agent, has a potent and selective activity against the intracellular and extracellular stages of Trypanosoma cruzi in vitro. It had a 50% inhibitory concentration of less than 5 micrograms/ml for T. cruzi extracellular cultured forms (epimastigote) and of 25 micrograms/ml for T. cruzi intracellular forms (amastigote) growing inside J774G8 macrophage-like cells. In contrast, the 50% inhibitory concentration was 100 micrograms/ml or greater for cultured mammalian cells and 180 micrograms/ml for the proliferation of mouse spleen lymphocytes. Furthermore, the addition of P536 (50 micrograms/ml) to T. cruzi-infected J774G8 cells cured the infected macrophages, making them able to grow and function normally. Studies on the mechanism of action of this drug indicated that it inhibited incorporation of [35S]methionine, [3H]thymidine, [3H]mannose, [14C]-N-acetylglucosamine, and [3H]uridine into macromolecules by T. cruzi epimastigotes, the last being the most sensitive

  5. Biological and molecular characterization of a raccoon isolate of Trypanosoma cruzi from South Carolina.

    Yabsley, Michael J; Noblet, Gayle Pittman

    2002-12-01

    Biological and molecular characteristics of a raccoon isolate of Trypanosoma cruzi (R36) were compared with those of a known virulent strain (Brazil). Included in the characterization were growth rate in liver infusion tryptose medium, infectivity for murine fibroblasts, intracellular amastigote replication and trypomastigote release rates, polymerase chain reaction (PCR) profiling of the mini-exon gene, isoenzyme and random amplified polymorphic DNA (RAPD) profiles, and in vivo virulence for C3H/HeJ mice. Similar growth curves were noted for both strains; however, infectivity and rates of intracellular amastigote replication and trypomastigote release were significantly lower for the R36 isolate than for the Brazil strain. To determine virulence, C3H/ HeJ mice were exposed intraperitoneally to the R36 isolate. No parasite was observed in blood by direct examination or in tissues by histology; however, T. cruzi was detected by PCR in tissues (quadriceps and spleen) at 21 days postinfection. Analyses of the mini-exon gene, isoenzyme, and RAPD profiles indicate that R36 is in the T. cruzi II group and the Brazil strain is in the T. cruzi I group. Although infectivity and virulence of the raccoon isolate were lower than those for the Brazil strain, autochthonous infections in the United States have been reported, which suggests the need for further study of local T. cruzi isolates. PMID:12537130

  6. Isolation and purification of a neutral alpha(1,2)-mannosidase from Trypanosoma cruzi.

    Bonay, P; Fresno, M

    1999-05-01

    Trypanosoma cruzi is an obligatory intracellular protozoan parasite that causes Chagas' disease in humans. Although a fair amount is known about the biochemistry of certain trypanosomes, very little is known about the enzymic complement of synthesis and processing of glycoproteins and/or functions of the subcellular organelles in this parasite. There have been very few reports on the presence of acid and neutral hydrolases in Trypanosoma cruzi. Here we report the first purification and characterization of a neutral mannosidase from the epimastigote stage of Trypanosoma cruzi. The neutral mannosidase was purified nearly 800-fold with an 8% recovery to apparent homogeneity from a CHAPS extract of epimastigotes by the following procedures: (1) metal affinity chromatography on Co+2-Sepharose, (2) anion exchange, and (3) hydroxylapatite. The purified enzyme has a native molecular weight of 150-160 kDa and is apparently composed of two subunits of 76 kDa. The purified enzyme exhibits a broad pH profile with a maximum at pH 5.9-6.3. It is inhibited by swainsonine (Ki, 0.1 microM), D-mannono-delta-lactam (Ki, 20 microM), kifunensine (Ki, 60 microM) but not significantly by deoxymannojirimycin. The enzyme is activated by Co2+and Ni2+and strongly inhibited by EDTA and Fe2+. The purified enzyme is active against p-nitrophenyl alpha-D-mannoside (km = 87 microM). High-mannose Man9GlcNAc substrate was hydrolyzed by the purified enzyme to Man7GlcNAc at pH 6.1. The purified enzyme does not show activity against alpha1,3- or alpha1,6-linked mannose residues. Antibodies against the recently purified lysosomal alpha-mannosidase from T.cruzi did not react with the neutral mannosidase reported here. PMID:10207175

  7. Mode of Action of the Sesquiterpene Lactones Psilostachyin and Psilostachyin C on Trypanosoma cruzi

    Papademetrio, Daniela; Batlle, Alcira; Martino, Virginia S.; Frank, Fernanda M.; Lombardo, María E.

    2016-01-01

    Trypanosoma cruzi is the causative agent of Chagas’ disease, which is a major endemic disease in Latin America and is recognized by the WHO as one of the 17 neglected tropical diseases in the world. Psilostachyin and psilostachyin C, two sesquiterpene lactones isolated from Ambrosia spp., have been demonstrated to have trypanocidal activity. Considering both the potential therapeutic targets present in the parasite, and the several mechanisms of action proposed for sesquiterpene lactones, the aim of this work was to characterize the mode of action of psilostachyin and psilostachyin C on Trypanosoma cruzi and to identify the possible targets for these molecules. Psilostachyin and psilostachyin C were isolated from Ambrosia tenuifolia and Ambrosia scabra, respectively. Interaction of sesquiterpene lactones with hemin, the induction of oxidative stress, the inhibition of cruzipain and trypanothione reductase and their ability to inhibit sterol biosynthesis were evaluated. The induction of cell death by apoptosis was also evaluated by analyzing phosphatidylserine exposure detected using annexin-V/propidium iodide, decreased mitochondrial membrane potential, assessed with Rhodamine 123 and nuclear DNA fragmentation evaluated by the TUNEL assay. Both STLs were capable of interacting with hemin. Psilostachyin increased about 5 times the generation of reactive oxygen species in Trypanosoma cruzi after a 4h treatment, unlike psilostachyin C which induced an increase in reactive oxygen species levels of only 1.5 times. Only psilostachyin C was able to inhibit the biosynthesis of ergosterol, causing an accumulation of squalene. Both sesquiterpene lactones induced parasite death by apoptosis. Upon evaluating the combination of both compounds, and additive trypanocidal effect was observed. Despite their structural similarity, both sesquiterpene lactones exerted their anti-T. cruzi activity through interaction with different targets. Psilostachyin accomplished its

  8. Synergy testing of FDA-approved drugs identifies potent drug combinations against Trypanosoma cruzi.

    Joseph D Planer

    2014-07-01

    Full Text Available An estimated 8 million persons, mainly in Latin America, are infected with Trypanosoma cruzi, the etiologic agent of Chagas disease. Existing antiparasitic drugs for Chagas disease have significant toxicities and suboptimal effectiveness, hence new therapeutic strategies need to be devised to address this neglected tropical disease. Due to the high research and development costs of bringing new chemical entities to the clinic, we and others have investigated the strategy of repurposing existing drugs for Chagas disease. Screens of FDA-approved drugs (described in this paper have revealed a variety of chemical classes that have growth inhibitory activity against mammalian stage Trypanosoma cruzi parasites. Aside from azole antifungal drugs that have low or sub-nanomolar activity, most of the active compounds revealed in these screens have effective concentrations causing 50% inhibition (EC50's in the low micromolar or high nanomolar range. For example, we have identified an antihistamine (clemastine, EC50 of 0.4 µM, a selective serotonin reuptake inhibitor (fluoxetine, EC50 of 4.4 µM, and an antifolate drug (pyrimethamine, EC50 of 3.8 µM and others. When tested alone in the murine model of Trypanosoma cruzi infection, most compounds had insufficient efficacy to lower parasitemia thus we investigated using combinations of compounds for additive or synergistic activity. Twenty-four active compounds were screened in vitro in all possible combinations. Follow up isobologram studies showed at least 8 drug pairs to have synergistic activity on T. cruzi growth. The combination of the calcium channel blocker, amlodipine, plus the antifungal drug, posaconazole, was found to be more effective at lowering parasitemia in mice than either drug alone, as was the combination of clemastine and posaconazole. Using combinations of FDA-approved drugs is a promising strategy for developing new treatments for Chagas disease.

  9. Trypanosoma cruzi extracts elicit protective immune response against chemically induced colon and mammary cancers.

    Ubillos, Luis; Freire, Teresa; Berriel, Edgardo; Chiribao, María Laura; Chiale, Carolina; Festari, María Florencia; Medeiros, Andrea; Mazal, Daniel; Rondán, Mariella; Bollati-Fogolín, Mariela; Rabinovich, Gabriel A; Robello, Carlos; Osinaga, Eduardo

    2016-04-01

    Trypanosoma cruzi, the protozoan parasite that causes Chagas' disease, has anticancer effects mediated, at least in part, by parasite-derived products which inhibit growth of tumor cells. We investigated whether immunity to T. cruzi antigens could induce antitumor activity, using two rat models which reproduce human carcinogenesis: colon cancer induced by 1,2-dimethylhydrazine (DMH), and mammary cancer induced by N-nitroso-N-methylurea (NMU). We found that vaccination with T. cruzi epimastigote lysates strongly inhibits tumor development in both animal models. Rats immunized with T. cruzi antigens induce activation of both CD4(+) and CD8(+) T cells and splenocytes from these animals showed higher cytotoxic responses against tumors as compared to rats receiving adjuvant alone. Tumor-associated immune responses included increasing number of CD11b/c(+) His48(-) MHC II(+) cells corresponding to macrophages and/or dendritic cells, which exhibited augmented NADPH-oxidase activity. We also found that T. cruzi lysate vaccination developed antibodies specific for colon and mammary rat cancer cells, which were capable of mediating antibody-dependent cellular cytotoxicity (ADCC) in vitro. Anti-T. cruzi antibodies cross-reacted with human colon and breast cancer cell lines and recognized 41/60 (68%) colon cancer and 38/63 (60%) breast cancer samples in a series of 123 human tumors. Our results suggest that T. cruzi antigens can evoke an integrated antitumor response involving both the cellular and humoral components of the immune response and provide novel insights into the understanding of the intricate relationship between parasite infection and tumor growth. PMID:26519949

  10. Trypanosoma cruzi CYP51 inhibitor derived from a Mycobacterium tuberculosis screen hit.

    Chiung-Kuang Chen

    Full Text Available BACKGROUND: The two front-line drugs for chronic Trypanosoma cruzi infections are limited by adverse side-effects and declining efficacy. One potential new target for Chagas' disease chemotherapy is sterol 14alpha-demethylase (CYP51, a cytochrome P450 enzyme involved in biosynthesis of membrane sterols. METHODOLOGY/PRINCIPAL FINDING: In a screening effort targeting Mycobacterium tuberculosis CYP51 (CYP51(Mt, we previously identified the N-[4-pyridyl]-formamide moiety as a building block capable of delivering a variety of chemotypes into the CYP51 active site. In that work, the binding modes of several second generation compounds carrying this scaffold were determined by high-resolution co-crystal structures with CYP51(Mt. Subsequent assays against the CYP51 orthologue in T. cruzi, CYP51(Tc, demonstrated that two of the compounds tested in the earlier effort bound tightly to this enzyme. Both were tested in vitro for inhibitory effects against T. cruzi and the related protozoan parasite Trypanosoma brucei, the causative agent of African sleeping sickness. One of the compounds had potent, selective anti-T. cruzi activity in infected mouse macrophages. Cure of treated host cells was confirmed by prolonged incubation in the absence of the inhibiting compound. Discrimination between T. cruzi and T. brucei CYP51 by the inhibitor was largely based on the variability (phenylalanine versus isoleucine of a single residue at a critical position in the active site. CONCLUSIONS/SIGNIFICANCE: CYP51(Mt-based crystal structure analysis revealed that the functional groups of the two tightly bound compounds are likely to occupy different spaces in the CYP51 active site, suggesting the possibility of combining the beneficial features of both inhibitors in a third generation of compounds to achieve more potent and selective inhibition of CYP51(Tc.

  11. High Trypanosoma cruzi infection prevalence associated with minimal cardiac pathology among wild carnivores in central Texas

    Rachel Curtis-Robles

    2016-08-01

    Full Text Available Infection with the zoonotic vector-borne protozoal parasite Trypanosoma cruzi causes Chagas disease in humans and dogs throughout the Americas. Despite the recognized importance of various wildlife species for perpetuating Trypanosoma cruzi in nature, relatively little is known about the development of cardiac disease in infected wildlife. Using a cross-sectional study design, we collected cardiac tissue and blood from hunter-donated wildlife carcasses- including raccoon (Procyon lotor, coyote (Canis latrans, gray fox (Urocyon cinereoargenteus, and bobcat (Lynx rufus – from central Texas, a region with established populations of infected triatomine vectors and increasing diagnoses of Chagas disease in domestic dogs. Based on PCR analysis, we found that 2 bobcats (14.3%, 12 coyotes (14.3%, 8 foxes (13.8%, and 49 raccoons (70.0% were positive for T. cruzi in at least one sample (right ventricle, apex, and/or blood clot. Although a histologic survey of right ventricles showed that 21.1% of 19 PCR-positive hearts were characterized by mild lymphoplasmocytic infiltration, no other lesions and no amastigotes were observed in any histologic section. DNA sequencing of the TcSC5D gene revealed that raccoons were infected with T. cruzi strain TcIV, and a single racoon harbored a TcI/TcIV mixed infection. Relative to other wildlife species tested here, our data suggest that raccoons may be important reservoirs of TcIV in Texas and a source of infection for indigenous triatomine bugs. The overall high level of infection in this wildlife community likely reflects high levels of vector contact, including ingestion of bugs. Although the relationship between the sylvatic cycle of T. cruzi transmission and human disease risk in the United States has yet to be defined, our data suggest that hunters and wildlife professionals should take precautions to avoid direct contact with potentially infected wildlife tissues.

  12. High Trypanosoma cruzi infection prevalence associated with minimal cardiac pathology among wild carnivores in central Texas.

    Curtis-Robles, Rachel; Lewis, Barbara C; Hamer, Sarah A

    2016-08-01

    Infection with the zoonotic vector-borne protozoal parasite Trypanosoma cruzi causes Chagas disease in humans and dogs throughout the Americas. Despite the recognized importance of various wildlife species for perpetuating Trypanosoma cruzi in nature, relatively little is known about the development of cardiac disease in infected wildlife. Using a cross-sectional study design, we collected cardiac tissue and blood from hunter-donated wildlife carcasses- including raccoon (Procyon lotor), coyote (Canis latrans), gray fox (Urocyon cinereoargenteus), and bobcat (Lynx rufus) - from central Texas, a region with established populations of infected triatomine vectors and increasing diagnoses of Chagas disease in domestic dogs. Based on PCR analysis, we found that 2 bobcats (14.3%), 12 coyotes (14.3%), 8 foxes (13.8%), and 49 raccoons (70.0%) were positive for T. cruzi in at least one sample (right ventricle, apex, and/or blood clot). Although a histologic survey of right ventricles showed that 21.1% of 19 PCR-positive hearts were characterized by mild lymphoplasmocytic infiltration, no other lesions and no amastigotes were observed in any histologic section. DNA sequencing of the TcSC5D gene revealed that raccoons were infected with T. cruzi strain TcIV, and a single racoon harbored a TcI/TcIV mixed infection. Relative to other wildlife species tested here, our data suggest that raccoons may be important reservoirs of TcIV in Texas and a source of infection for indigenous triatomine bugs. The overall high level of infection in this wildlife community likely reflects high levels of vector contact, including ingestion of bugs. Although the relationship between the sylvatic cycle of T. cruzi transmission and human disease risk in the United States has yet to be defined, our data suggest that hunters and wildlife professionals should take precautions to avoid direct contact with potentially infected wildlife tissues. PMID:27330982

  13. Genotyping of Trypanosoma cruzi DTUs and Trypanosoma rangeli genetic groups in experimentally infected Rhodnius prolixus by PCR-RFLP.

    Sá, Amanda R N; Dias, Greicy B M; Kimoto, Karen Y; Steindel, Mário; Grisard, Edmundo C; Toledo, Max Jean O; Gomes, Mônica L

    2016-04-01

    The specific detection and genetic typing of trypanosomes that infect humans, mammalian reservoirs, and vectors is crucial for diagnosis and epidemiology. We utilized a PCR-RFLP assay that targeted subunit II of cytochrome oxidase and 24Sα-rDNA to simultaneously detect and discriminate six Trypanosoma cruzi discrete typing units (DTUs) and two genetic groups of Trypanosoma rangeli (KP1+/KP1-) in intestinal contents of experimentally infected Rhodnius prolixus. The PCR assays showed that in 23 of 29 (79.4%) mixed infections with the six T. cruzi DTUs and mixed infections with individual DTUs and/or groups KP1+ and KP1-, both parasites were successfully detected. In six mixed infections that involved TcIII, the TcI, TcII, TcV, and TcVI DTUs predominated to the detriment of TcIII, indicating the selection of genetic groups. Interactions between different genetic groups and vectors may lead to genetic selection over TcIII. The elimination of this DTU by the immune system of the vector appears unlikely because TcIII was present in other mixed infections (TcIII/TcIV and TcIII/KP1+). Both molecular markers used in this study were sensitive and specific, demonstrating their usefulness in a wide geographical area where distinct genotypes of these two species are sympatric. Although the cellular and molecular mechanisms that are involved in parasite-vector interactions are still poorly understood, our results indicate a dynamic selection toward specific T. cruzi DTUs in R. prolixus during mixed genotype infections. PMID:26792202

  14. Trypanosoma Cruzi Cyp51 Inhibitor Derived from a Mycobacterium Tuberculosis Screen Hit

    Chen, Chiung-Kuang; Doyle, Patricia S.; Yermalitskaya, Liudmila V.; Mackey, Zachary B.; Ang, Kenny K.H.; McKerrow, James H.; Podust, Larissa M.; (Vanderbilt); (UCSF)

    2009-02-18

    The two front-line drugs for chronic Trypanosoma cruzi infections are limited by adverse side-effects and declining efficacy. One potential new target for Chagas disease chemotherapy is sterol 14{alpha}-demethylase (CYP51), a cytochrome P450 enzyme involved in biosynthesis of membrane sterols. In a screening effort targeting Mycobacterium tuberculosis CYP51 (CYP51{sub Mt}), we previously identified the N-[4-pyridyl]-formamide moiety as a building block capable of delivering a variety of chemotypes into the CYP51 active site. In that work, the binding modes of several second generation compounds carrying this scaffold were determined by high-resolution co-crystal structures with CYP51{sub Mt}. Subsequent assays against the CYP51 orthologue in T. cruzi, CYP51{sub Tc}, demonstrated that two of the compounds tested in the earlier effort bound tightly to this enzyme. Both were tested in vitro for inhibitory effects against T. cruzi and the related protozoan parasite Trypanosoma brucei, the causative agent of African sleeping sickness. One of the compounds had potent, selective anti-T. cruzi activity in infected mouse macrophages. Cure of treated host cells was confirmed by prolonged incubation in the absence of the inhibiting compound. Discrimination between T. cruzi and T. brucei CYP51 by the inhibitor was largely based on the variability (phenylalanine versus isoleucine) of a single residue at a critical position in the active site. CYP51{sub Mt}-based crystal structure analysis revealed that the functional groups of the two tightly bound compounds are likely to occupy different spaces in the CYP51 active site, suggesting the possibility of combining the beneficial features of both inhibitors in a third generation of compounds to achieve more potent and selective inhibition of CYP51{sub Tc}. Enzyme sterol 14{alpha}-demethylase (CYP51) is a well-established target for anti-fungal therapy and is a prospective target for Chagas disease therapy. We previously identified a

  15. Environment, interactions between Trypanosoma cruzi and its host, and health Meio-ambiente, interações entre Trypanosoma cruzi e seu hospedeiro e saúde humana

    Antonio R. L. Teixeira

    2009-01-01

    Full Text Available An epidemiological chain involving Trypanosoma cruzi is discussed at the environmental level, and in terms of fine molecular interactions in invertebrate and vertebrate hosts dwelling in different ecosystems. This protozoan has a complex, genetically controlled plasticity, which confers adaptation to approximately 40 blood-sucking triatomine species and to over 1,000 mammalian species, fulfilling diverse metabolic requirements in its complex life-cycle. The Tr. cruzi infections are deeply embedded in countless ecotypes, where they are difficult to defeat using the control methods that are currently available. Many more field and laboratory studies are required to obtain data and information that may be used for the control and prevention of Tr. cruzi infections and their various disease manifestations. Emphasis should be placed on those sensitive interactions at cellular and environmental levels that could become selected targets for disease prevention. In the short term, new technologies for social mobilization should be used by people and organizations working for justice and equality through health information and promotion. A mass media directed program could deliver education, information and communication to protect the inhabitants at risk of contracting Tr. cruzi infections.Uma rede epidemiológica envolvendo o Trypanosoma cruzi foi discutida nos níveis ambientais e de interações moleculares nos hospedeiros que habitam em 19 diferentes ecossistemas. O protozoário tem uma enorme plasticidade controlada geneticamente que confere sua adaptação a cerca de quarenta espécies de triatomíneos e mais de mil espécies de mamíferos. Essas infecções estão profundamente embutidas em inúmeros ecótopos, onde elas estão inacessíveis aos métodos de controle utilizados. Muito mais estudos de campo e de laboratório são necessários à obtenção de dados e informação pertinentes ao controle e prevenção das infecções pelo Tr. cruzi e

  16. Wild Trypanosoma cruzi I genetic diversity in Brazil suggests admixture and disturbance in parasite populations from the Atlantic Forest region

    Lima, VS; Jansen, AM; Messenger, LA; Miles, MA; Llewellyn, MS

    2014-01-01

    BACKGROUND Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) infection is an ancient and widespread zoonosis distributed throughout the Americas. Ecologically, Brazil comprises several distinct biomes: Amazonia, Cerrado, Caatinga, Pantanal and the Atlantic Forest. Sylvatic T. cruzi transmission is known to occur throughout these biomes, with multiple hosts and vectors involved. Parasite species-level genetic diversity can be a useful marker for ecosystem health. Our aims were to: investiga...

  17. In vitro biological evaluation of eight different essential oils against Trypanosoma cruzi, with emphasis on Cinnamomum verum essential oil

    Azeredo, Camila Maria O; Santos, Thalita Gilda; Maia, Beatriz Helena Lameiro de Noronha Sales; Soares, Maurilio José

    2014-01-01

    Background Essential oils (EOs) are complex mixtures of secondary metabolites from various plants. It has been shown that several EOs, or their constituents, have inhibitory activity against trypanosomatid protozoa. Thus, we analyzed the biological activity of different EOs on Trypanosoma cruzi, as well as their cytotoxicity on Vero cells. Methods The following EOs were evaluated on T. cruzi epimastigote forms: Cinnamomum verum, Citrus limon, Cymbopogon nardus, Corymbia citriodora, Eucalyptus...

  18. A simple method to purify biologically and antigenically preserved bloodstream trypomastigotes of Trypanosoma cruzi using Deae-cellulose columns

    Maria Auxiliadora de Sousa

    1983-01-01

    A method to purify trypanosomastigotes of some strains of Trypanosoma cruzi (Y, CL, FL, F, "Berenice", "Colombiana" and "São Felipe") from mouse blood by using DEAE-cellulose columns was standardized. This procedure is a modification of the Lanham & Godfrey methods and differs in some aspects from others described to purify T. cruzi bloodstream trypomastigotes, mainly by avoidance of prior purifications of parasites. By this method, the broad trypomastigotes were mainly isolated, accounting f...

  19. Dual Role of Signaling Pathways Leading to Ca2+ and Cyclic AMP Elevation in Host Cell Invasion by Trypanosoma cruzi

    Caler, Elisabet V.; Morty, Rory E; Burleigh, Barbara A.; Andrews, Norma W.

    2000-01-01

    Cell invasion by the protozoan parasite Trypanosoma cruzi involves activation of host signaling pathways and the recruitment and fusion of lysosomes at the parasite entry site. A major signaling pathway regulating invasion of fibroblasts, epithelial cells, and myoblasts involves mobilization of Ca2+ from intracellular stores and requires the activity of a T. cruzi serine peptidase, oligopeptidase B (OPB). Deletion of the OPB gene results in a marked defect in trypomastigote virulence, consist...

  20. Utility of the Trypanosoma cruzi Sequence Database for Identification of Potential Vaccine Candidates by In Silico and In Vitro Screening

    Bhatia, Vandanajay; Sinha, Mala; Luxon, Bruce; Garg, Nisha

    2004-01-01

    Glycosylphosphatidylinositol (GPI)-anchored proteins are abundantly expressed in the infective and intracellular stages of Trypanosoma cruzi and are recognized as antigenic targets by both the humoral and cellular arms of the immune system. Previously, we demonstrated the efficacy of genes encoding GPI-anchored proteins in eliciting partially protective immunity to T. cruzi infection and disease, suggesting their utility as vaccine candidates. For the identification of additional vaccine targ...

  1. Structural characterization of CYP51 from Trypanosoma cruzi and Trypanosoma brucei bound to the antifungal drugs posaconazole and fluconazole.

    Chiung-Kuang Chen

    Full Text Available BACKGROUND: Chagas Disease is the leading cause of heart failure in Latin America. Current drug therapy is limited by issues of both efficacy and severe side effects. Trypansoma cruzi, the protozoan agent of Chagas Disease, is closely related to two other major global pathogens, Leishmania spp., responsible for leishmaniasis, and Trypansoma brucei, the causative agent of African Sleeping Sickness. Both T. cruzi and Leishmania parasites have an essential requirement for ergosterol, and are thus vulnerable to inhibitors of sterol 14alpha-demethylase (CYP51, which catalyzes the conversion of lanosterol to ergosterol. Clinically employed anti-fungal azoles inhibit ergosterol biosynthesis in fungi, and specific azoles are also effective against both Trypanosoma and Leishmania parasites. However, modification of azoles to enhance efficacy and circumvent potential drug resistance has been problematic for both parasitic and fungal infections due to the lack of structural insights into drug binding. METHODOLOGY/PRINCIPAL FINDINGS: We have determined the crystal structures for CYP51 from T. cruzi (resolutions of 2.35 A and 2.27 A, and from the related pathogen T. brucei (resolutions of 2.7 A and 2.6 A, co-crystallized with the antifungal drugs fluconazole and posaconazole. Remarkably, both drugs adopt multiple conformations when binding the target. The fluconazole 2,4-difluorophenyl ring flips 180 degrees depending on the H-bonding interactions with the BC-loop. The terminus of the long functional tail group of posaconazole is bound loosely in the mouth of the hydrophobic substrate binding tunnel, suggesting that the major contribution of the tail to drug efficacy is for pharmacokinetics rather than in interactions with the target. CONCLUSIONS/SIGNIFICANCE: The structures provide new insights into binding of azoles to CYP51 and mechanisms of potential drug resistance. Our studies define in structural detail the CYP51 therapeutic target in T. cruzi, and

  2. Should Trypanosoma cruzi be called "cruzi" complex? A review of the parasite diversity and the potential of selecting population after in Vitro culturing and mice infection

    Devera Rodolfo

    2003-01-01

    Full Text Available Morpho-biological diversity of Trypanosoma cruzi has been known since Chagas' first works in 1909. Several further studies confirmed the morphological differences among the parasite strains, which were isolated from different reservoirs and vectors, as well as from human beings. In the early sixties, antigenic differences were found in the parasite strains from various sources. These differences, coupled to the observation of regional variations of the disease, led to the proposal of the term cruzi complex to designate the taxon T. cruzi. Since then this protozoan has been typed in distinct biodemes, zymodemes and lineages which were consensually grouped into T. cruzi I, T. cruzi II and into non-grouped strains. T. cruzi genotypic characterization, initially carried out by schizodeme analysis and more recently by various other techniques, has shown a great diversity of the parasite strains. In fact, T. cruzi is formed by groups of heterogeneous sub-population, which present specific characteristics, including distinct histotropism. The interaction of the different infecting clones of the cruzi complex and the human host will determine the morbidity of the disease.

  3. Trypanosoma cruzi Needs a Signal Provided by Reactive Oxygen Species to Infect Macrophages

    Goes, Grazielle R.; Rocha, Peter S.; Diniz, Aline R. S.; Aguiar, Pedro H. N.; Machado, Carlos R.; Vieira, Leda Q.

    2016-01-01

    Background During Trypanosoma cruzi infection, macrophages produce reactive oxygen species (ROS) in a process called respiratory burst. Several works have aimed to elucidate the role of ROS during T. cruzi infection and the results obtained are sometimes contradictory. T. cruzi has a highly efficiently regulated antioxidant machinery to deal with the oxidative burst, but the parasite macromolecules, particularly DNA, may still suffer oxidative damage. Guanine (G) is the most vulnerable base and its oxidation results in formation of 8-oxoG, a cellular marker of oxidative stress. Methodology/Principal Findings In order to investigate the contribution of ROS in T. cruzi survival and infection, we utilized mice deficient in the gp91phox (Phox KO) subunit of NADPH oxidase and parasites that overexpress the enzyme EcMutT (from Escherichia coli) or TcMTH (from T. cruzi), which is responsible for removing 8-oxo-dGTP from the nucleotide pool. The modified parasites presented enhanced replication inside murine inflammatory macrophages from C57BL/6 WT mice when compared with control parasites. Interestingly, when Phox KO macrophages were infected with these parasites, we observed a decreased number of all parasites when compared with macrophages from C57BL/6 WT. Scavengers for ROS also decreased parasite growth in WT macrophages. In addition, treatment of macrophages or parasites with hydrogen peroxide increased parasite replication in Phox KO mice and in vivo. Conclusions Our results indicate a paradoxical role for ROS since modified parasites multiply better inside macrophages, but proliferation is significantly reduced when ROS is removed from the host cell. Our findings suggest that ROS can work like a signaling molecule, contributing to T. cruzi growth inside the cells. PMID:27035573

  4. Early Regulation of Profibrotic Genes in Primary Human Cardiac Myocytes by Trypanosoma cruzi.

    Udoko, Aniekanabassi N; Johnson, Candice A; Dykan, Andrey; Rachakonda, Girish; Villalta, Fernando; Mandape, Sammed N; Lima, Maria F; Pratap, Siddharth; Nde, Pius N

    2016-01-01

    The molecular mechanisms of Trypanosoma cruzi induced cardiac fibrosis remains to be elucidated. Primary human cardiomyoctes (PHCM) exposed to invasive T. cruzi trypomastigotes were used for transcriptome profiling and downstream bioinformatic analysis to determine fibrotic-associated genes regulated early during infection process (0 to 120 minutes). The identification of early molecular host responses to T. cruzi infection can be exploited to delineate important molecular signatures that can be used for the classification of Chagasic patients at risk of developing heart disease. Our results show distinct gene network architecture with multiple gene networks modulated by the parasite with an incline towards progression to a fibrogenic phenotype. Early during infection, T. cruzi significantly upregulated transcription factors including activator protein 1 (AP1) transcription factor network components (including FOSB, FOS and JUNB), early growth response proteins 1 and 3 (EGR1, EGR3), and cytokines/chemokines (IL5, IL6, IL13, CCL11), which have all been implicated in the onset of fibrosis. The changes in our selected genes of interest did not all start at the same time point. The transcriptome microarray data, validated by quantitative Real-Time PCR, was also confirmed by immunoblotting and customized Enzyme Linked Immunosorbent Assays (ELISA) array showing significant increases in the protein expression levels of fibrogenic EGR1, SNAI1 and IL 6. Furthermore, phosphorylated SMAD2/3 which induces a fibrogenic phenotype is also upregulated accompanied by an increased nuclear translocation of JunB. Pathway analysis of the validated genes and phospho-proteins regulated by the parasite provides the very early fibrotic interactome operating when T. cruzi comes in contact with PHCM. The interactome architecture shows that the parasite induces both TGF-β dependent and independent fibrotic pathways, providing an early molecular foundation for Chagasic cardiomyopathy

  5. The Increase in Mannose Receptor Recycling Favors Arginase Induction and Trypanosoma Cruzi Survival in Macrophages

    Vanina V. Garrido, Laura R. Dulgerian, Cinthia C. Stempin, Fabio M. Cerbán

    2011-01-01

    Full Text Available The macrophage mannose receptor (MR is a pattern recognition receptor of the innate immune system that binds to microbial structures bearing mannose, fucose and N-acetylglucosamine on their surface. Trypanosoma cruzi antigen cruzipain (Cz is found in the different developmental forms of the parasite. This glycoprotein has a highly mannosylated C-terminal domain that participates in the host-antigen contact. Our group previously demonstrated that Cz-macrophage (Mo interaction could modulate the immune response against T. cruzi through the induction of a preferential metabolic pathway. In this work, we have studied in Mo the role of MR in arginase induction and in T. cruzi survival using different MR ligands. We have showed that pre-incubation of T. cruzi infected cells with mannose-Bovine Serum Albumin (Man-BSA, MR specific ligand biased nitric oxide (NO/urea balance towards urea production and increased intracellular amastigotes growth. The study of intracellular signals showed that pre-incubation with Man-BSA in T. cruzi J774 infected cells induced down-regulation of JNK and p44/p42 phosphorylation and increased of p38 MAPK phosphorylation. These results are coincident with previous data showing that Cz also modifies the MAPK phosphorylation profile induced by the parasite. In addition, we have showed by confocal microscopy that Cz and Man-BSA enhance MR recycling. Furthermore, we studied MR behavior during T. cruzi infection in vivo. MR was up-regulated in F4/80+ cells from T. cruzi infected mice at 13 and 15 days post infection. Besides, we investigated the effect of MR blocking antibody in T. cruzi infected peritoneal Mo. Arginase activity and parasite growth were decreased in infected cells pre-incubated with anti-MR antibody as compared with infected cells treated with control antibody. Therefore, we postulate that during T. cruzi infection, Cz may contact with MR, increasing MR recycling which leads to arginase activity up-regulation and

  6. Trypanosoma cruzi among wild and domestic mammals in different areas of the Abaetetuba municipality (Pará State, Brazil), an endemic Chagas disease transmission area.

    Roque, André Luiz R; Xavier, Samanta C C; Gerhardt, Marconny; Silva, Miguel F O; Lima, Valdirene S; D'Andrea, Paulo S; Jansen, Ana M

    2013-03-31

    The presence of acute Chagas disease (ACD) due to oral transmission is growing and expanding in several South American countries. Within the Amazon basin, the Abaetetuba municipality has been a site of recurrent cases spanning across distinct landscapes. Because Chagas disease is primarily a zoonotic infection, we compared the enzootic Trypanosoma cruzi transmission cycles in three different environmental areas of Abaetetuba to better understand this new epidemiological situation. Philander opossum was the most abundant mammalian species collected (38% of the collected mammals) with a T. cruzi prevalence of 57%, as determined by hemocultures. Didelphis marsupialis was abundant only in the area with the higher level of environmental disturbance (approximately 42%) and did not yield detectable parasitemia. Despite similarities observed in the composition of the small mammalian fauna and the prevalence of T. cruzi infection among the studied areas, the potential of these hosts to infect vectors differed significantly according to the degree of land use (with prevalences of 5%, 41%, and 64% in areas A3, A1 and A2, respectively). Domestic mammals were also found to be infected, and one canine T. cruzi isolate was obtained. Our data demonstrated that the transmission of T. cruzi in the Amazon basin is far more complex than had been previously taught and showed that the probability of humans and domestic mammals coming into contact with infected bugs can vary dramatically, even within the same municipality. The exposure of dogs to T. cruzi infection (indicated by positive serology) was the common feature among the studied localities, stressing the importance of selecting domestic mammals as sentinels in the identification of T. cruzi transmission hotspots. PMID:23261089

  7. IgG isotype profile is correlated with cardiomegaly in Beagle dogs infected with distinct Trypanosoma cruzi strains.

    Guedes, Paulo M M; Veloso, Vanja M; Gollob, Kenneth J; Afonso, Luis C C; Caldas, Ivo S; Vianna, Priscila; de Lana, Marta; Chiari, Egler; Bahia, Maria T; Galvão, Lúcia M C

    2008-07-15

    A systematic study following infection by various strains of the protozoan parasite, Trypanosoma cruzi, and the simultaneous monitoring of the humoral immune response together with the elicited cellular response, could add greatly to our understanding of differences between strains of this important human pathogen. In that sense, acute and chronic infections with distinct T. cruzi strains (Y, Berenice-78 and ABC) in Beagle dogs were studied through a longitudinal evaluation of immunoglobulin G (IgG), IgG1 and IgG2 isotypes (by ELISA and flow cytometry (FC)), as well as measurements of peripheral blood mononuclear cell (PBMC) proliferation over a 100-week period, and their correlation with cardiomegaly. Our results show that infected animals presenting cardiomegaly showed lower or absent levels of IgG1 during the chronic phase of the infection, when compared to those that did not show an increase in heart weight. In that manner, our results suggest that IgG1 could be used as a marker for cardiac pathogenicity in Chagas disease. PMID:18439688

  8. Assessing the vulnerability of Brazilian municipalities to the vectorial transmission of Trypanosoma cruzi using multi-criteria decision analysis.

    Vinhaes, Márcio Costa; de Oliveira, Stefan Vilges; Reis, Priscilleyne Ouverney; de Lacerda Sousa, Ana Carolina; Silva, Rafaella Albuquerque E; Obara, Marcos Takashi; Bezerra, Cláudia Mendonça; da Costa, Veruska Maia; Alves, Renato Vieira; Gurgel-Gonçalves, Rodrigo

    2014-09-01

    Despite the dramatic reduction in Trypanosoma cruzi vectorial transmission in Brazil, acute cases of Chagas disease (CD) continue to be recorded. The identification of areas with greater vulnerability to the occurrence of vector-borne CD is essential to prevention, control, and surveillance activities. In the current study, data on the occurrence of domiciliated triatomines in Brazil (non-Amazonian regions) between 2007 and 2011 were analyzed. Municipalities' vulnerability was assessed based on socioeconomic, demographic, entomological, and environmental indicators using multi-criteria decision analysis (MCDA). Overall, 2275 municipalities were positive for at least one of the six triatomine species analyzed (Panstrongylus megistus, Triatoma infestans, Triatoma brasiliensis, Triatoma pseudomaculata, Triatoma rubrovaria, and Triatoma sordida). The municipalities that were most vulnerable to vector-borne CD were mainly in the northeast region and exhibited a higher occurrence of domiciliated triatomines, lower socioeconomic levels, and more extensive anthropized areas. Most of the 39 new vector-borne CD cases confirmed between 2001 and 2012 in non-Amazonian regions occurred within the more vulnerable municipalities. Thus, MCDA can help to identify the states and municipalities that are most vulnerable to the transmission of T. cruzi by domiciliated triatomines, which is critical for directing adequate surveillance, prevention, and control activities. The methodological approach and results presented here can be used to enhance CD surveillance in Brazil. PMID:24857942

  9. A therapeutic nanoparticle vaccine against Trypanosoma cruzi in a BALB/c mouse model of Chagas disease.

    Barry, Meagan A; Wang, Qian; Jones, Kathryn M; Heffernan, Michael J; Buhaya, Munir H; Beaumier, Coreen M; Keegan, Brian P; Zhan, Bin; Dumonteil, Eric; Bottazzi, Maria Elena; Hotez, Peter J

    2016-04-01

    Chagas disease, caused by Trypanosoma cruzi, results in an acute febrile illness that progresses to chronic chagasic cardiomyopathy in 30% of patients. Current treatments have significant side effects and poor efficacy during the chronic phase; therefore, there is an urgent need for new treatment modalities. A robust TH1-mediated immune response correlates with favorable clinical outcomes. A therapeutic vaccine administered to infected individuals could bolster the immune response, thereby slowing or stopping the progression of chagasic cardiomyopathy. Prior work in mice has identified an efficacious T. cruzi DNA vaccine encoding Tc24. To elicit a similar protective cell-mediated immune response to a Tc24 recombinant protein, we utilized a poly(lactic-co-glycolic acid) nanoparticle delivery system in conjunction with CpG motif-containing oligodeoxynucleotides as an immunomodulatory adjuvant. In a BALB/c mouse model, the vaccine produced a TH1-biased immune response, as demonstrated by a significant increase in antigen-specific IFNγ-producing splenocytes, IgG2a titers, and proliferative capacity of CD8(+) T cells. When tested for therapeutic efficacy, significantly reduced systemic parasitemia was seen during peak parasitemia. Additionally, there was a significant reduction in cardiac parasite burden and inflammatory cell infiltrate. This is the first study demonstrating immunogenicity and efficacy of a therapeutic Chagas vaccine using a nanoparticle delivery system. PMID:26890466

  10. Trypanosoma cruzi in the anal glands of urban opossums: I- isolation and experimental infections

    S Urdaneta-Morales

    1996-08-01

    Full Text Available Opossums (Didelphis marsupialis captured in intensely urbanized areas of the city of Caracas, Venezuela, were found infected with Trypanosoma cruzi. The developmental cycle of trypomastigote-epimastigote-metacyclic infective trypomastigote, usually occurring in the intestine of the triatomine vector, was taking place in the anal odoriferous glands of the opossums. Material from the glands, inoculated in young, healthy opossums and white mice by different routes, subcutaneously, intraperitoneally, orally, and into the eye, induced T. cruzi infections in all animals. Parasitemia, invasion of cardiac and skeletal muscle, and intracellular multiplication of amastigotes were observed. Inoculation of metacyclics from anal glands, cultured in LIT medium, gave equivalent results. All opossums survived; all mice died. Excreta of opossums may thus transmit Chagas' disease by contamination, even in urban areas where insect vectors are not present.