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Sample records for anti-trypanosoma cruzi activity

  1. Synthesis and Anti-Trypanosoma cruzi Activity of Diaryldiazepines

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    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.

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

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    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

  3. Synthesis and Anti-Trypanosoma cruzi Activity of Diaryldiazepines

    OpenAIRE

    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...

  4. In Vitro and in Vivo Anti-Trypanosoma cruzi Activity of a Novel Nitro-derivative

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    Susana Muelas-Serrano

    2002-06-01

    Full Text Available Nitroarylidenemalononitriles and their cyanoacetamide derivatives with remarkable anti-epimastigote properties, were synthesized attempting to obtain new 3,5-diamino-4-(5'-nitroarylidene-4H-thiadiazine 1,1-dioxide derivatives, which in previous reports had shown anti-Trypanosoma cruzi activity. Tests to evaluate the cytotoxicity of compounds were performed on J774 macrophages. 5-nitro-2-thienyl-malononitrile (5NO2TM, was the only product which maintained a high anti-epimastigote activity at concentrations in which it was no longer cytotoxic, thus it was assayed against intracellular amastigotes. Its anti-amastigote activity was similar to that of nifurtimox. Afterwards in vivo toxicity and anti-chagasic activity were determined. A reduction in parasitemia was observed.

  5. Mutagenic activation of CL64,855, an anti-Trypanosoma cruzi nitroderivant, by bacterial nitroreductases

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    Morais Jr. Marcos Antonio de

    1998-01-01

    Full Text Available CL64,855 is a nitroimidazole-thiodiazole derivate with high anti-Trypanosoma cruzi activity. CL64,855-induced mutagenesis in the Salmonella/microsome test was detected by TA98 and TA98dnp6 strains, but not by the nitroreductase I-deficient TA98nr strain. The lack of mutagenic response of TA98nr was connected with its extreme resistance to the killing effect of the drug. Presence of S9 mix did not restore mutagenic activity of CL64,855 to the TA98nr strain. Additionally, CL64,855 was reduced in vitro by the nitroreductase I-proficient TA98 strain, mainly in the presence of oxygen, but not by the TA98nr strain. Mutagenic activity was detected in serum samples of treated guinea pigs by nitroreductase-proficient strains TA98 and TA98dnp6, but not by nitroductase-deficient strain TA98nr. In the case of urine, mutagenic activity was observed with all three tested strains, suggesting an in vivo metabolic activation of the drug by a distinct metabolic pathway.

  6. Anti-Trypanosoma cruzi activity of green tea (Camellia sinensis) catechins.

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    Paveto, Cristina; Güida, María C; Esteva, Mónica I; Martino, Virginia; Coussio, Jorge; Flawiá, Mirtha M; Torres, Héctor N

    2004-01-01

    The trypanocidal action of green tea catechins against two different developmental stages of Trypanosoma cruzi is reported for the first time. This activity was assayed with the nonproliferative bloodstream trypomastigote and with the intracellular replicative amastigote parasite forms. An ethyl acetate fraction from Camellia sinensis green tea leaves, which contains most of the polyphenolic compounds and the maximal trypanocidal activity, was obtained by fractionation of the aqueous extract with organic solvents. The active compounds present in this extract were further purified by LH-20 column chromatography and were identified by high-performance liquid chromatography analysis with a photo diode array detector and gas chromatography coupled to mass spectroscopy. The following flavan-3-ols derivatives, known as catechins, were identified: catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, and epigallocatechin gallate. The purified compounds lysed more than 50% of the parasites present in the blood of infected BALB/c mice at concentrations as low as 0.12 to 85 pM. The most active compounds were gallocatechin gallate and epigallocatechin gallate, with minimal bactericidal concentrations that inhibited 50% of isolates tested of 0.12 and 0.53 pM, respectively. The number of amastigotes in infected Vero cells decreased by 50% in the presence of each of these compounds at 100 nM. The effects of the catechins on the recombinant T. cruzi arginine kinase, a key enzyme in the energy metabolism of the parasite, were assayed. The activity of this enzyme was inhibited by about 50% by nanomolar concentrations of catechin gallate or gallocatechin gallate, whereas the other members of the group were less effective. On the basis of these results, we suggest that these compounds could be used to sterilize blood and, eventually, as therapeutic agents for Chagas' disease.

  7. Anti-Trypanosoma cruzi activity of 10 medicinal plants used in northeast Mexico.

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    Molina-Garza, Zinnia Judith; Bazaldúa-Rodríguez, Aldo Fabio; Quintanilla-Licea, Ramiro; Galaviz-Silva, Lucio

    2014-08-01

    The aim of this study was to screen the trypanocidal activity of plants used in traditional Mexican medicine for the treatment of various diseases related to parasitic infections. Cultured Trypanosoma cruzi epimastigotes were incubated for 96h with different concentrations of methanolic extracts obtained from Artemisia mexicana, Castela texana, Cymbopogon citratus, Eryngium heterophyllum, Haematoxylum brasiletto, Lippia graveolens, Marrubium vulgare, Persea americana, Ruta chalepensis and Schinus molle. The inhibitory concentration (IC50) was determined for each extract via a colorimetric method. Among the evaluated species, the methanolic extracts of E. heterophyllum, H. brasiletto, M. vulgare and S. molle exhibited the highest trypanocidal activity, showing percentages of growth inhibition between 88 and 100% at a concentration of 150μg/ml. These medicinal plants may represent a valuable source of new bioactive compounds for the therapeutic treatment of trypanosomiasis. PMID:24742906

  8. Anti-Trypanosoma cruzi activity of 10 medicinal plants used in northeast Mexico.

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    Molina-Garza, Zinnia Judith; Bazaldúa-Rodríguez, Aldo Fabio; Quintanilla-Licea, Ramiro; Galaviz-Silva, Lucio

    2014-08-01

    The aim of this study was to screen the trypanocidal activity of plants used in traditional Mexican medicine for the treatment of various diseases related to parasitic infections. Cultured Trypanosoma cruzi epimastigotes were incubated for 96h with different concentrations of methanolic extracts obtained from Artemisia mexicana, Castela texana, Cymbopogon citratus, Eryngium heterophyllum, Haematoxylum brasiletto, Lippia graveolens, Marrubium vulgare, Persea americana, Ruta chalepensis and Schinus molle. The inhibitory concentration (IC50) was determined for each extract via a colorimetric method. Among the evaluated species, the methanolic extracts of E. heterophyllum, H. brasiletto, M. vulgare and S. molle exhibited the highest trypanocidal activity, showing percentages of growth inhibition between 88 and 100% at a concentration of 150μg/ml. These medicinal plants may represent a valuable source of new bioactive compounds for the therapeutic treatment of trypanosomiasis.

  9. In Vivo Anti-Trypanosoma cruzi Activity of Hydro-Ethanolic Extract and Isolated Active Principles from Aristeguietia glutinosa and Mechanism of Action Studies

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    Javier Varela; Elva Serna; Susana Torres; Gloria Yaluff; Vera de Bilbao, Ninfa I.; Patricio Miño; Ximena Chiriboga; Hugo Cerecetto; Mercedes González

    2014-01-01

    The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Attempting to find alternative drugs isolated from Nature as agents against Trypanosoma cruzi has been our goal. Recently, we have demonstrated the in vitro anti-T. cruzi activities of two secondary metabolites isolated from the hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa (Lam.), (family Asteraceae). These active principles displayed...

  10. In vivo anti-Trypanosoma cruzi activity of hydro-ethanolic extract and isolated active principles from Aristeguietia glutinosa and mechanism of action studies.

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    Varela, Javier; Serna, Elva; Torres, Susana; Yaluff, Gloria; de Bilbao, Ninfa I Vera; Miño, Patricio; Chiriboga, Ximena; Cerecetto, Hugo; González, Mercedes

    2014-01-01

    The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Attempting to find alternative drugs isolated from Nature as agents against Trypanosoma cruzi has been our goal. Recently, we have demonstrated the in vitro anti-T. cruzi activities of two secondary metabolites isolated from the hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa (Lam.), (family Asteraceae). These active principles displayed poor hemolytic activity, low toxicity against murine macrophages, and absence of mutagenicity. Herein, proof of concept in vivo studies of the whole hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa and of the most active component isolated from the hydro-ethanolic extract, i.e., (+)-15-hydroxy-7-labden-17-al, was done in a murine acute model of Chagas disease. Both treatments caused a decrease in the animals' parasitemia. Metabolomic mechanism of action studies were done by 1H-NMR, both on the extract and on the active compounds, examining the effects of the metabolites both on membrane sterol biosynthesis and mitochondrial dehydrogenases, whereby we found that one of the metabolites inhibited the activity of the parasite mitochondrial dehydrogenases and the other inhibited the biosynthesis of parasite membrane sterols. The results are interesting in the context of popular use of plants for the treatment of Chagas disease. PMID:24959677

  11. In Vivo Anti-Trypanosoma cruzi Activity of Hydro-Ethanolic Extract and Isolated Active Principles from Aristeguietia glutinosa and Mechanism of Action Studies

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    Javier Varela

    2014-06-01

    Full Text Available The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Attempting to find alternative drugs isolated from Nature as agents against Trypanosoma cruzi has been our goal. Recently, we have demonstrated the in vitro anti-T. cruzi activities of two secondary metabolites isolated from the hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa (Lam., (family Asteraceae. These active principles displayed poor hemolytic activity, low toxicity against murine macrophages, and absence of mutagenicity. Herein, proof of concept in vivo studies of the whole hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa and of the most active component isolated from the hydro-ethanolic extract, i.e., (+-15-hydroxy-7-labden-17-al, was done in a murine acute model of Chagas disease. Both treatments caused a decrease in the animals’ parasitemia. Metabolomic mechanism of action studies were done by 1H-NMR, both on the extract and on the active compounds, examining the effects of the metabolites both on membrane sterol biosynthesis and mitochondrial dehydrogenases, whereby we found that one of the metabolites inhibited the activity of the parasite mitochondrial dehydrogenases and the other inhibited the biosynthesis of parasite membrane sterols. The results are interesting in the context of popular use of plants for the treatment of Chagas disease.

  12. Chemical composition and anti-Trypanosoma cruzi activity of essential oils obtained from leaves of Xylopia frutescens and X. laevigata (Annonaceae).

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    da Silva, Thanany Brasil; Menezes, Leociley Rocha Alencar; Sampaio, Marília Fernanda Chaves; Meira, Cássio Santana; Guimarães, Elisalva Teixeira; Soares, Milena Botelho Pereira; Prata, Ana Paula do Nascimento; Nogueira, Paulo Cesar de Lima; Costa, Emmanoel Vilaça

    2013-03-01

    Essential oils from leaves of Xylopia frutescens (XFMJ) and two specimens of Xylopia laevigata (XLMC and XLSI) were obtained by hydrodistillation using a Clevenger-type apparatus, and analyzed by GC-MS and GC-FID. Sesquiterpenes dominated the essential oils. The main constituents of XFMJ were (E)-caryophyllene (24.8%), bicyclogermacrene (20.8%), germacrene D (17.0%), beta-elemene (7.9%), and (E)-beta-ocimene (6.8%). XLMC contained significant quantities of germacrene D (18.9%), bicyclogermacrene (18.4%), beta-elemene (9.5%), delta-selinene (9.2%), (E)-caryophyllene (8.5%), germacrene B (5.7%) and gamma-muurolene (5.7%), while germacrene D (27.0%), bicyclogermacrene (12.8%), (E)-caryophyllene (8.6%), gamma-muurolene (8.6%), delta-cadinene (6.8%), and germacrene B (6.0%) were the main components of XLSI. The essential oils had trypanocidal activity against the Y strain of Trypanosoma cruzi, with IC50 values lower than 30 microg x mL(-1) and 15 microg x mL(-1) against epimastigote and trypomastigote forms of T. cruzi, respectively, and were also able to reduce the percentage in vitro of T. cruzi-infected macrophages and the intracellular number of amastigotes at concentrations that were non-cytotoxic to macrophages.

  13. Expanding the family of heteroleptic oxidovanadium(IV) compounds with salicylaldehyde semicarbazones and polypyridyl ligands showing anti-Trypanosoma cruzi activity.

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    Scalese, Gonzalo; Benítez, Julio; Rostán, Santiago; Correia, Isabel; Bradford, Lara; Vieites, Marisol; Minini, Lucía; Merlino, Alicia; Coitiño, E Laura; Birriel, Estefania; Varela, Javier; Cerecetto, Hugo; González, Mercedes; Pessoa, João Costa; Gambino, Dinorah

    2015-06-01

    Searching for prospective vanadium-based drugs for the treatment of Chagas disease, a new series of heteroleptic [V(IV)O(L-2H)(NN)] compounds was developed by including the lipophilic 3,4,7,8-tetramethyl-1,10-phenanthroline (tmp) NN ligand and seven tridentate salicylaldehyde semicarbazone derivatives (L1-L7). The compounds were characterized in the solid state and in solution. EPR spectroscopy suggests that the NN ligand is bidentate bound through both nitrogen donor atoms in an axial-equatorial mode. The EPR and (51)V-NMR spectra of aerated solutions at room temperature indicate that the compounds are stable to hydrolysis and that no significant oxidation of V(IV) to V(V) takes place at least in 24h. The complexes are more active in vitro against Trypanosoma cruzi, the parasite responsible for Chagas disease, than the reference drug Nifurtimox and most of them are more active than previously reported [V(IV)O(L-2H)(NN)] complexes of other NN co-ligands. Selectivity towards the parasite was analyzed using J-774 murine macrophages as mammalian cell model. Due to both, high activity and high selectivity, L2, L4, L5 and L7 complexes could be considered new hits for further drug development. Lipophilicity probably plays a relevant role in the bioactivity of the new compounds. The [V(IV)O(L-2H)(NN)] compounds were designed aiming DNA as potential molecular target. Therefore, the novel L1-L7 tmp complexes were screened by computational modeling, comparing their DNA-binding features with those of previously reported [V(IV)O(L-2H)(NN)] compounds with different NN co-ligands. Whereas all the complexes interact well with DNA, with binding modes and strength tuned in different extents by the NN and semicarbazone co-ligands, molecular docking suggests that the observed anti-T. cruzi activity cannot be explained upon DNA intercalation as the sole mechanism of action. PMID:25824466

  14. Bioactive-guided identification of labdane diterpenoids from aerial parts of Aristeguietia glutinosa as anti-Trypanosoma cruzi agents.

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    Varela, Javier; Lavaggi, María L; Cabrera, Mauricio; Rodríguez, Alejandra; Miño, Patricio; Chiriboga, Ximena; Cerecetto, Hugo; González, Mercedes

    2012-09-01

    A bioactive-guided investigation of the hydro-ethanolic extract of aerial parts of Aristeguietia glutinosa Lam. resulted in the isolation of two diterpenoids, (+)-15-hydroxy-labd-7-en-17-al (1) and (+)-13,14,15,16-tetranor-labd-7-en-17,12-olide (2), as the anti-Trypanosoma cruzi active principles. The structures of 1 and 2 were determined by spectroscopic analysis. The hydro-ethanolic extract showed anti-T. cruzi activity (IC50 = 19.6 microg/mL) whereas the isolated compounds 1 and 2 were near to seven- and one and a half-fold (IC50 = 3.0 and 15.6 microg/mL), respectively more active than the original extract. Labdene 1, equipotent as the reference compound (Nifurtimox), displayed low hemolytic activity, low toxicity against murine macrophages, and absence of mutagenicity. These results support the vernacular medicinal use of this plant as an anti-T. cruzi agent. PMID:23074890

  15. Standardization of serological tests for detecting anti-Trypanosoma cruzi antibodies in dogs

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    M. A. Lauricella

    1993-09-01

    Full Text Available This paper reports on the standardization of four serological reactions currently used in human serodiagnosis for the detection of anti-Trypanosoma cruzi antibodies in naturally and experimentally infected dogs. Indirect immunofluorescence test (IFAT and hemagglutination test (IHAT were standardized, and complement fixation test (CFT and direct agglutination test (DAT were used for diagnostic confirmation. Four hundred and eighty one mongrel dogs that were studied by xenodiagnosis were used: (1 parasitemic dogs of two localities of endemic area (EA of Santiago del Estero province in Argentina (n = 134; (2 non-parasitemic dogs of the same area (n = 285; (3 dogs experimentally infected with T. cruzi in the patent period (n = 6; (4 non-infected dogs (n = 56 which were born in the city of Buenos Aires (BA, one non-EA for Chagas' disease. For IFAT, parasitemic dogs EA showed 95% of reactive sera. Non parasitemic dogs EA showed 77% of non reactive sera. None sera from BA were reactive for dilutions higher than four. For IHAT, 84% of sera of parasitemic dogs EA showed serological reactivity and among non parasitemic dogs BA, 61% were non reactive, while the remainder showed at most titres of 1/16. The cut-off titres for IFAT and IHAT were 1/16 and 1/32 respectively, and for CFT and DAT 1/1 and 1/128 respectively. Sensitivity for IFAT, IHAT, CF and DAT were 95%, 84%, 97% and 95% respectively.

  16. Nitro/Nitrosyl-Ruthenium Complexes Are Potent and Selective Anti-Trypanosoma cruzi Agents Causing Autophagy and Necrotic Parasite Death

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    Bastos, Tanira M.; Barbosa, Marília I. F.; da Silva, Monize M.; da C. Júnior, José W.; Meira, Cássio S.; Guimaraes, Elisalva T.; Ellena, Javier; Moreira, Diogo R. M.; Batista, Alzir A.

    2014-01-01

    cis-[RuCl(NO2)(dppb)(5,5′-mebipy)] (complex 1), cis-[Ru(NO2)2(dppb)(5,5′-mebipy)] (complex 2), ct-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2 (complex 3), and cc-[RuCl(NO)(dppb)(5,5′-mebipy)](PF6)2 (complex 4), where 5,5′-mebipy is 5,5′-dimethyl-2,2′-bipyridine and dppb is 1,4-bis(diphenylphosphino)butane, were synthesized and characterized. The structure of complex 2 was determined by X-ray crystallography. These complexes exhibited a higher anti-Trypanosoma cruzi activity than benznidazole, the current antiparasitic drug. Complex 3 was the most potent, displaying a 50% effective concentration (EC50) of 2.1 ± 0.6 μM against trypomastigotes and a 50% inhibitory concentration (IC50) of 1.3 ± 0.2 μM against amastigotes, while it displayed a 50% cytotoxic concentration (CC50) of 51.4 ± 0.2 μM in macrophages. It was observed that the nitrosyl complex 3, but not its analog lacking the nitrosyl group, releases nitric oxide into parasite cells. This release has a diminished effect on the trypanosomal protease cruzain but induces substantial parasite autophagy, which is followed by a series of irreversible morphological impairments to the parasites and finally results in cell death by necrosis. In infected mice, orally administered complex 3 (five times at a dose of 75 μmol/kg of body weight) reduced blood parasitemia and increased the survival rate of the mice. Combination index analysis of complex 3 indicated that its in vitro activity against trypomastigotes is synergic with benznidazole. In addition, drug combination enhanced efficacy in infected mice, suggesting that ruthenium-nitrosyl complexes are potential constituents for drug combinations. PMID:25092707

  17. Isoquinoline-based analogs of the cancer drug clinical candidate tipifarnib as anti-Trypanosoma cruzi agents

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    Chennamaneni, Naveen Kumar; Arif, Jenifer; Buckner, Frederick S.; Gelb, Michael H

    2009-01-01

    We developed a synthetic route to prepare isoquinoline analogs of the cancer drug clinical candidate tipifarnib. We show that these compounds kill Trypanosoma cruzi amastigotes grown in mammalian host cells at concentrations in the low nanomolar range. These isoquinolines represent new leads for the development of drugs to treat Chagas disease.

  18. 4-Aminopyridyl-Based CYP51 Inhibitors as Anti-Trypanosoma cruzi Drug Leads with Improved Pharmacokinetic Profile and in Vivo Potency

    OpenAIRE

    Calvet, Claudia M.; Vieira, Debora F.; Choi, Jun Yong; Kellar, Danielle; Cameron, Michael D.; de Siqueira-Neto, Jair Lage; Gut, Jiri; Johnston, Jonathan B.; Lin, Li; Khan, Susan; McKerrow, James H.; Roush, William R.; Larissa M. Podust

    2014-01-01

    CYP51 is a P450 enzyme involved in the biosynthesis of the sterol components of eukaryotic cell membranes. CYP51 inhibitors have been developed to treat infections caused by fungi, and more recently the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. To specifically optimize drug candidates for T. cruzi CYP51 (TcCYP51), we explored the structure–activity relationship (SAR) of a N-indolyl-oxopyridinyl-4-aminopropanyl-based scaffold originally identified in a target...

  19. [Comparison of the indirect immunofluorescent (IFAT), ELISA test and the comercial Chagatek test for anti-Trypanosoma cruzi antibodies detection].

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    Enciso, Clara; Montilla, Marleny; Santacruz, María M; Nicholls, Rubén Santiago; Rodríguez, Adriana; Mercado, Marcela; Puerta, Concepción

    2004-03-01

    Chagas disease is a public health problem in Colombia, particularly in the eastern region. Because of human migration from rural areas to urban centers, the possibility of transfusional transmission becomes increasingly important. However the risk can be minimized by a careful screening of blood donors by means of serological tests. Colombian blood banks use comercial, foreign serological tests for screening for T. cruzi infection. The purpose of the current study was to compare the IFAT and ELISA tests (both use antigen obtained from Colombian strains) with the comercially available Chagatek tests. Sera of blood donors were classified in two groups on the basis of the IFAT: group I, 15 positive patients and group II, 14 negative patients. Sera from each group were tested by the ELISA and Chagatek tests. The ELISA test detected 100% of the patients as positive in group I and 7% (1/14) of patients as positive in group II. The Chagatek test detected 93% (14/15) of the patients as positive in group I and 50% (7/14) in group II. The kappa index for concordance between the ELISA and IFAT tests was 0.93 (95% C.I.: 0.80-1.00); between IFAT and Chagatek 0.43 (95% C.I.: 0.26-0.62), and between ELISA and Chagatek 0.49 (95% C.I.: 0.31-0.67). These results highlighted the importance of using autochtonous Colombian strains as antigens in screening tests for blood donors.

  20. Mexican Trypanosoma cruzi isolates: in vitro susceptibility of epimastigotes to anti-trypanosoma cruzi drugs and metacyclic forms to complement-mediated lysis.

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    León-Pérez, Floribeth; Gómez-Garcia, Lorena; Alejandre-Aguilar, R; López, R; Monteón, V M

    2007-01-01

    Trypanosoma cruzi has a clonal organization with an ample array of genetic and phenotypic features and probably anaploid constitution. Consequently, the biological behavior, biochemistry, and molecular attributes may be distinctive for each parasite strain in different geographical regions. As far as we know, there is no published information on the susceptibility of Mexican T. cruzi stocks to anti-T. cruzi drugs such as benznidazole and gentian violet, or on its resistance to complement-mediated lysis. We studied 10 Mexican T. cruzi isolates from different geographical areas, such as the pacific coast (Oaxaca, Guerrero, and Nayarit States), central part of Mexico (Guanajuato State), Gulf of Mexico (Veracruz State), and the Yucatan Peninsula (Campeche State). We searched for the natural resistance to drugs in in vitro assay against the 10 Mexican isolates using epimastigote forms and the complement-mediated lysis using metacyclic trypomastigotes insect-derived in three of them (one for each geographic region). In general, we observed high resistance to benznidazole in all the Mexican isolates tested, but in the complement-mediated lysis test, they showed moderate to high susceptibility. Although it is necessary to expand this study by using trypomastigotes and the intracellular form to verify its biological role, we suggest that Mexican T. cruzi parasites may have a variable susceptibility to antibody-mediated lysis and high resistance to benznidazole.

  1. 4-Aminopyridyl-based CYP51 inhibitors as anti-Trypanosoma cruzi drug leads with improved pharmacokinetic profile and in vivo potency.

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    Calvet, Claudia M; Vieira, Debora F; Choi, Jun Yong; Kellar, Danielle; Cameron, Michael D; Siqueira-Neto, Jair Lage; Gut, Jiri; Johnston, Jonathan B; Lin, Li; Khan, Susan; McKerrow, James H; Roush, William R; Podust, Larissa M

    2014-08-28

    CYP51 is a P450 enzyme involved in the biosynthesis of the sterol components of eukaryotic cell membranes. CYP51 inhibitors have been developed to treat infections caused by fungi, and more recently the protozoan parasite Trypanosoma cruzi, the causative agent of Chagas disease. To specifically optimize drug candidates for T. cruzi CYP51 (TcCYP51), we explored the structure-activity relationship (SAR) of a N-indolyl-oxopyridinyl-4-aminopropanyl-based scaffold originally identified in a target-based screen. This scaffold evolved via medicinal chemistry to yield orally bioavailable leads with potent anti-T. cruzi activity in vivo. Using an animal model of infection with a transgenic T. cruzi Y luc strain expressing firefly luciferase, we prioritized the biaryl and N-arylpiperazine analogues by oral bioavailability and potency. The drug-target complexes for both scaffold variants were characterized by X-ray structure analysis. Optimization of both binding mode and pharmacokinetic properties of these compounds led to potent inhibitors against experimental T. cruzi infection. PMID:25101801

  2. CL 64, 855, a potent do anti-Trypanosoma cruzi drug, is also mutagenic in the salmonella/microsome assay

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    R. C. C. Ferreira

    1986-03-01

    Full Text Available The nitroimidazole-tiadiazole derivative CL 64,855 (2-amino-5-(1-methyl-5-nitro-2-imidazolyl-1,3,4-thiadiazole, a potent anti-trypanosomal drug, was assayed in a short-term bacterial mutagenicity test with Salmonella typhimurium strains TA 98, TA 100 and TA 102. Results indicate that CL 64,855 is a potent frameshift mutagen detected by strains TA 98 and TA 102. CL 64,855 was able to revert the indicators strains at concentrations as low as 0.1 µg/plate. Metabolic activation experiments with rat liver microsomal fractions did not increase the mutagenic action of Cl 64,855.O derivado nitroimizadole-tiadizol CL 64.855 (2-amino-5-(1-metil-5-nitro-2-imidazoli-1, 3, 4-tiadiazol, um potente agente tripanomicida, foi submetido a um ensaio mutagênico bacteriano com as linhagens indicadoras de Salmonella typhimurium TA 98, TA 100 e TA 102. Os resultados indicaram que o CL 64.855 é um potente mutagênico tipo troca de referencial detectado pelas linhagens TA 98 e TA 102. O CL 64.855 foi capaz de reverter as linhagens indicadoras em concentrações tão baixas quatro 0,1microng/placa. Ativação metabólica com frações microssomais de fígado de rato foram incapazes de aumentar a ação mutagênica do CL 64.855.

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

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    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.

  4. Estudo fitoquímico e avaliação in vitro da atividade anti-Trypanosoma cruzi cepa Y de Pilocarpus spicatus St. Hil. (Rutaceae)

    OpenAIRE

    Silva, C.V.; F.C.C. Bomfim; M.A.V. dos Santos; E.S Velozo

    2014-01-01

    A investigação química da espécie Pilocarpus spicatus, popularmente conhecida como jaborandi e usada na medicina tradicional para doenças como estomatite, febre, bronquite e psoríase, teve por objetivo o isolamento e/ou identificação de substâncias ativas e a avaliação da atividade antiparasitária dos extratos frente às formas epimastigotas de Trypanosoma cruzi. O estudo resultou na identificação de nove substâncias, tais como: tridecanona, 2-heptadecanona, espatulenol, aromadendreno, β-cario...

  5. Blood transfusion and iatrogenic risks in Mexico city: anti-Trypanosoma cruzi seroprevalence in 43,048 blood donors, evaluation of parasitemia, and electrocardiogram findings in seropositive

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    Nidia Hernández-Becerril

    2005-04-01

    Full Text Available Iatrogenous transmission of Trypanosoma cruziby blood transfusion was suggested as a potential risk by Pellegrino (1949. Seropositive blood donors in Mexico were first reported in 1978, however, limited information is available due to small sampling, the use of heterogeneous serologic assays, and geographically limited studies. A wide survey carried out in 18 out of the 32 states of Mexico, showed a national mean of 1.6% seropositive among 64,969 donors, ranging from 0.2 to 2.8%. In the present study, we have screened 43,048 voluntary blood donors in a period of five years at the Instituto Nacional de Cardiología I. Chávez, a concentration hospital located in Mexico city which serves mainly the metropolitan area and accepts from all over the country. Standardized ELISA and IIF were used to identify seropositive individuals in addition to hemoculture, PCR and standard 12 lead ECG tests that were applied to a group of seropositive patients (29/161. The result showed a seropositivity of 0.37% (161/43,048. From the group of seropositive individuals 40% (12/29 were potential carriers of T. cruzi at the donation time and 5/29 had subclinical ECG abnormalities. Parasitological tests performed in 70 erythrocyte and platelet fractions from seropositive units (70/161 showed negative results. Our findings strongly support T. cruzi screening in the transfusion medicine practice and identify subclinical heart disease among seropositive blood donors.

  6. Estudo fitoquímico e avaliação in vitro da atividade anti-Trypanosoma cruzi cepa Y de Pilocarpus spicatus St. Hil. (Rutaceae

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    C.V Silva

    2014-12-01

    Full Text Available A investigação química da espécie Pilocarpus spicatus, popularmente conhecida como jaborandi e usada na medicina tradicional para doenças como estomatite, febre, bronquite e psoríase, teve por objetivo o isolamento e/ou identificação de substâncias ativas e a avaliação da atividade antiparasitária dos extratos frente às formas epimastigotas de Trypanosoma cruzi. O estudo resultou na identificação de nove substâncias, tais como: tridecanona, 2-heptadecanona, espatulenol, aromadendreno, β-cariofileno, ácido 3α-hidroxitirucala-7,24-dien-21-óico, (+-isoangenomalina, episesamina e sesamina. As estr uturas dos compostos foram elucidadas por análises espectroscópicas e comparação com dados da literatura. Os extratos hexânico e metanólico de folhas e raízes foram testados in vitro contra o Trypanosoma cruzi cepa Y e apresentaram atividade tripanomicida.

  7. Distribución heterogénea de la prevalencia de anticuerpos contra Trypanosoma cruzi en donadores de sangre en Puebla, México Heterogeneous distribution of the prevalence of anti-Trypanosoma cruzi antibodies among blood donors in the State of Puebla, Mexico

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    Víctor M Monteón

    2005-04-01

    Full Text Available OBJETIVO: Identificar la seroprevalencia de anticuerpos anti Trypanosoma cruzi (Ac anti-T. cruzi en donadores de sangre que habitan en ámbito rural y suburbano, así como las regiones del estado de mayor riesgo y factores asociados. MATERIAL Y MÉTODOS: Estudio transversal realizado de enero a diciembre de 2003. Se analizaron 2 489 donadores de sangre reclutados en 10 puestos de sangrado del Instituto Mexicano del Seguro Social (IMSS distribuidos en las siete regiones económicas del estado de Puebla, México. Se determinó la seroprevalencia mediante las pruebas serológicas obligatorias del panel viral y, además, para T. cruzi, región de reclutamiento y de origen de los donadores. RESULTADOS: La seroprevalencia de Ac anti-T. cruzi fue de 1.24% (31/2 489 comparable con la obtenida para el virus de la hepatitis C (1.5% y por arriba de la del virus de la inmunodeficiencia humana (0.4% y del antígeno de superficie del virus de la hepatitis B (0.3%. Las regiones de Tehuacán-Sierra Negra y Mixteca fueron las de mayor riesgo con seroprevalencias, por el origen del donador, de 2.6% para T. cruzi, mientras que en los originarios de las regiones Sierra nororiental y Angelópolis no se detectaron casos positivos. Se observó asociación entre ser seropositivo y mayor de 40 años y ser originario de las regiones de Tehuacán-Sierra Negra y Mixteca. CONCLUSIONES: La distribución de seroprevalencia a T. cruzi es heterogénea, oscila desde 0% hasta 2.6%, y se reconoce a Tehuacán-Sierra Negra y Mixteca como las regiones de mayor riesgo.OBJECTIVE: To determine the seroprevalence and associated factors, of antibodies against Trypanosoma cruzi (T. cruzi Ab among blood donors living in rural and suburban areas and risk regions. MATERIAL AND METHODS: A cross-sectional study was conducted from January to December 2003, in 2489 blood donors of seven regions of Puebla, who were evaluated for mandatory viral and T. cruzi serological tests using validated

  8. Identification of Trypanocidal Activity for Known Clinical Compounds Using a New Trypanosoma cruzi Hit-Discovery Screening Cascade.

    Science.gov (United States)

    De Rycker, Manu; Thomas, John; Riley, Jennifer; Brough, Stephen J; Miles, Tim J; Gray, David W

    2016-04-01

    Chagas disease is a significant health problem in Latin America and the available treatments have significant issues in terms of toxicity and efficacy. There is thus an urgent need to develop new treatments either via a repurposing strategy or through the development of new chemical entities. A key first step is the identification of compounds with anti-Trypanosoma cruzi activity from compound libraries. Here we describe a hit discovery screening cascade designed to specifically identify hits that have the appropriate anti-parasitic properties to warrant further development. The cascade consists of a primary imaging-based assay followed by newly developed and appropriately scaled secondary assays to predict the cidality and rate-of-kill of the compounds. Finally, we incorporated a cytochrome P450 CYP51 biochemical assay to remove compounds that owe their phenotypic response to inhibition of this enzyme. We report the use of the cascade in profiling two small libraries containing clinically tested compounds and identify Clemastine, Azelastine, Ifenprodil, Ziprasidone and Clofibrate as molecules having appropriate profiles. Analysis of clinical derived pharmacokinetic and toxicity data indicates that none of these are appropriate for repurposing but they may represent suitable start points for further optimisation for the treatment of Chagas disease. PMID:27082760

  9. Identification of Trypanocidal Activity for Known Clinical Compounds Using a New Trypanosoma cruzi Hit-Discovery Screening Cascade.

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    Manu De Rycker

    2016-04-01

    Full Text Available Chagas disease is a significant health problem in Latin America and the available treatments have significant issues in terms of toxicity and efficacy. There is thus an urgent need to develop new treatments either via a repurposing strategy or through the development of new chemical entities. A key first step is the identification of compounds with anti-Trypanosoma cruzi activity from compound libraries. Here we describe a hit discovery screening cascade designed to specifically identify hits that have the appropriate anti-parasitic properties to warrant further development. The cascade consists of a primary imaging-based assay followed by newly developed and appropriately scaled secondary assays to predict the cidality and rate-of-kill of the compounds. Finally, we incorporated a cytochrome P450 CYP51 biochemical assay to remove compounds that owe their phenotypic response to inhibition of this enzyme. We report the use of the cascade in profiling two small libraries containing clinically tested compounds and identify Clemastine, Azelastine, Ifenprodil, Ziprasidone and Clofibrate as molecules having appropriate profiles. Analysis of clinical derived pharmacokinetic and toxicity data indicates that none of these are appropriate for repurposing but they may represent suitable start points for further optimisation for the treatment of Chagas disease.

  10. Designing and exploring active N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides against three Trypanosoma cruzi strains more prevalent in Chagas disease patients.

    Science.gov (United States)

    Palace-Berl, Fanny; Pasqualoto, Kerly Fernanda Mesquita; Jorge, Salomão Dória; Zingales, Bianca; Zorzi, Rodrigo Rocha; Silva, Marcelo Nunes; Ferreira, Adilson Kleber; de Azevedo, Ricardo Alexandre; Teixeira, Sarah Fernandes; Tavares, Leoberto Costa

    2015-01-01

    Chagas disease affects around 8 million people worldwide and its treatment depends on only two nitroheterocyclic drugs, benznidazole (BZD) and nifurtimox (NFX). Both drugs have limited curative power in chronic phase of disease. Nifuroxazide (NF), a nitroheterocyclic drug, was used as lead to design a set of twenty one compounds in order to improve the anti-Trypanosoma cruzi activity. Lipinski's rules were considered in order to support drug-likeness designing. The set of N'-[(5-nitrofuran-2-yl) methylene] substituted hydrazides was assayed against three T. cruzi strains, which represent the discrete typing units more prevalent in human patients: Y (TcII), Silvio X10 cl1 (TcI), and Bug 2149 cl10 (TcV). All the derivatives, except one, showed enhanced trypanocidal activity against the three strains as compared to BZD. In the Y strain 62% of the compounds were more active than NFX. The most active compound was N'-((5-nitrofuran-2-yl) methylene)biphenyl-4-carbohydrazide (C20), which showed IC50 values of 1.17 ± 0.12 μM; 3.17 ± 0.32 μM; and 1.81 ± 0.18 μM for Y, Silvio X10 cl1, and Bug 2149 cl10 strains, respectively. Cytotoxicity assays with human fibroblast cells have demonstrated high selectivity indices for several compounds. Exploratory data analysis indicated that primarily topological, steric/geometric, and electronic properties have contributed to the discrimination of the set of investigated compounds. The findings can be helpful to drive the designing, and subsequently, the synthesis of additional promising drugs against Chagas disease. PMID:25899337

  11. The characterization of anti-T. cruzi activity relationships between ferrocenyl, cyrhetrenyl complexes and ROS release.

    Science.gov (United States)

    Echeverría, César; Romero, Valentina; Arancibia, Rodrigo; Klahn, Hugo; Montorfano, Ignacio; Armisen, Ricardo; Borgna, Vincenzo; Simon, Felipe; Ramirez-Tagle, Rodrigo

    2016-08-01

    Trypanosoma cruzi (T. cruzi) is the parasite that causes Chagas disease. Nifurtimox is the most used drug against the T. cruzi, this drug increases intermediaries nitro group, being mainly responsible for the high toxicity component, for this reason it is important to study new organic compounds and thus improve therapeutic strategies against Chagas disease. The electronic effects of ferrocenyl and cyrhetrenyl fragments were investigated by DFT calculation. A close correlation was found between HOMO-LUMO gap of nitro radical NO 2 (-) with the experimental reduction potential found for nitro group and IC50 of two forms the T. cruzi (epimastigote and trypomastigote). The IC50 on human hepatoma cells is higher for both compounds compared to IC50 demonstrated in the two forms the T. cruzi, and additionally show reactive oxygen species release. The information obtained in this paper could generate two new drugs with anti-T. cruzi activity, but additional studies are needed. PMID:27460450

  12. Efecto del aceite esencial de Aloysia triphylla britton (cedrón sobre el Trypanosoma cruzi en ratones The effect of the essential oil from Aloysia triphylla britton (lemon verbena on Trypanosoma cruzi in mice

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    Juan Rojas

    2012-03-01

    Full Text Available Objetivos. Determinar la actividad anti-Trypanosoma cruzi in vivo del aceite esencial de Aloysia triphylla en ratones. Materiales y Métodos. Los animales fueron asignados aleatoriamente a los siguientes grupos (n = 15 por grupo: infectados y no tratados (G1, infectados y tratados con benznidazol 100 mg/kg (G2, infectados y tratados con aceite esencial de Aloysia triphylla 100 mg/kg (G3, infectados y tratados con aceite esencial de Aloysia triphylla 250 mg/kg (G4; no infectados y no tratados (G5, y no infectados y tratados con 250 mg/kg de Aloysia triphyla (G6. La infección con T. cruzi se realizó con 104 tripomastigotes sanguíneos y el tratamiento empezó en el octavo día postinfección (dpi hasta el 28 dpi. La parasitemia se determinó con microscopía óptica cada dos días en 5 μL de sangre extraída de la cola. En el 14, 21 y 28 dpi se obtuvo sangre de la cola para el ensayo de creatina kinasa-MB (CK-MB, alanina aminotransferasa y creatinina; después, los animales fueron sacrificados y se extrajo el corazón para el estudio histopatológico. Resultados. El aceite esencial de cedrón produjo una reducción significativa de 85,4% del pico de parasitemia con la dosis de 250 mg/kg; también produjo reducción del número de amastigotes e infiltrados inflamatorios en el corazón. El nivel plasmático de CK-MB también disminuyó en el 28 dpi por efecto de dicho tratamiento. Conclusiones. En condiciones experimentales, el aceite esencial de Aloysia triphylla tiene efecto anti-Trypanosoma cruzi in vivo en ratones.Objectives. To determine the in-vivo anti-Trypanosoma cruzi activity of the essential oil from Aloysia triphylla in mice. Materials and methods. The mice (n = 15 in the study were randomly assigned to the following groups: infected and untreated (G1, infected and treated with benznidazole 100 mg/kg (G2, infected and treated with of Aloysia triphylla essential oil 100 mg/kg (G3, infected and treated with of Aloysia triphylla

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

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    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.

  14. Synthesis of Xylitan Derivatives and Preliminary Evaluation of in Vitro Trypanocidal Activity

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    Paula Regina Elias

    2016-10-01

    Full Text Available A series of novel xylitan derivatives derived from xylitol were synthesized using operationally simple procedures. A xylitan acetonide was the key intermediate used to prepare benzoate, arylsulfonate esters and 1,2,3-triazole derivatives of xylitan. These compounds were evaluated for their in vitro anti-Trypanosoma cruzi activity against trypomastigote and amastigote forms of the parasite in T. cruzi-infected cell lineages. Benznidazole was used as positive control against T. cruzi and cytotoxicity was determined in mammalian L929 cells. The arylsulfonate xylitan derivative bearing a nitro group displayed the best activity of all the compounds tested, and was slightly more potent than the reference drug benznidazole. The importance of the isopropylidene ketal moiety was established and the greater lipophilicity of these compounds suggests enhancement in cell penetration.

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

    Science.gov (United States)

    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

  16. Active transcription and ultrastructural changes during Trypanosoma cruzi metacyclogenesis

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    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

  17. Effects of platelet-activating factor on the interaction of Trypanosoma cruzi with Rhodnius prolixus.

    Science.gov (United States)

    Zimmermann, Luciana T; Folly, Evelize; Gomes, Marta T; Alviano, Daniela S; Alviano, Celuta S; Silva-Filho, Fernando C; Atella, Geórgia C; Lopes, Angela H

    2011-06-01

    We investigated the effects of platelet-activating factor (PAF) on the interaction of Trypanosoma cruzi with Rhodnius prolixus. The parasites (epimastigotes) were treated with PAF and/or WEB 2086 (PAF antagonist) for 1 h prior to the interaction experiments. PAF stimulated both in vivo and ex vivo interactions between T. cruzi and R. prolixus while WEB 2086 abrogated these effects. PAF-treated epimastigotes also showed an increase in surface negativity and in the amount of surface sialic acid. Neither of these effects was observed when the epimastigotes were treated with neuraminidase following PAF treatment. In the ex vivo interaction experiments, the number of epimastigotes bound to the midguts of the insects was reduced when the epimastigotes had been treated with neuraminidase. We conclude that PAF modulates the interaction of T. cruzi with R. prolixus by altering the amount of sialyl residues at the surface of the parasite.

  18. Trypanosoma cruzi calreticulin inhibits the complement lectin pathway activation by direct interaction with L-Ficolin.

    Science.gov (United States)

    Sosoniuk, Eduardo; Vallejos, Gerardo; Kenawy, Hany; Gaboriaud, Christine; Thielens, Nicole; Fujita, Teizo; Schwaeble, Wilhelm; Ferreira, Arturo; Valck, Carolina

    2014-07-01

    Trypanosoma cruzi, the agent of Chagas' disease, the sixth neglected tropical disease worldwide, infects 10-12 million people in Latin America. Differently from T. cruzi epimastigotes, trypomastigotes are complement-resistant and infective. CRPs, T-DAF, sialic acid and lipases explain at least part of this resistance. In vitro, T. cruzi calreticulin (TcCRT), a chaperone molecule that translocates from the ER to the parasite surface: (a) Inhibits the human classical complement activation, by interacting with C1, (b) As a consequence, an increase in infectivity is evident and, (c) It inhibits angiogenesis and tumor growth. We report here that TcCRT also binds to the L-Ficolin collagenous portion, thus inhibiting approximately between 35 and 64% of the human complement lectin pathway activation, initiated by L-Ficolin, a property not shared by H-Ficolin. While L-Ficolin binds to 60% of trypomastigotes and to 24% of epimastigotes, 50% of the former and 4% of the latter display TcCRT on their surfaces. Altogether, these data indicate that TcCRT is a parasite inhibitory receptor for Ficolins. The resulting evasive activities, together with the TcCRT capacity to inhibit C1, with a concomitant increase in infectivity, may represent T. cruzi strategies to inhibit important arms of the innate immune response.

  19. The activity of a metronidazole analogue and its β-cyclodextrin complex against Trypanosoma cruzi

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    Marcela Silva Lopes

    2011-12-01

    Full Text Available In this study we prepared an inclusion complex between an iodide analogue of metronidazole (MTZ-I and cyclodextrin (CD to develop a safer and more effective method of treating Trypanosoma cruzi infections. According to our results, MTZ-I and MTZ-I:β-CD were 10 times more active than MTZ, demonstrating that the presence of an iodine atom on the side chain increased the trypanocidal activity while maintaining its cytotoxicity. The selective index shows that MTZ-I was 10 times more active against T. cruzi than it was against mammalian cells. The modification of MTZ side chains provides a promising avenue for the development of new drugs.

  20. Preparation and evaluation of a coumarin library towards the inhibitory activity of the enzyme gGAPDH from Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Alvim Junior, Joel; Dias, Ricardo L.A.; Correa, Arlene G. [Universidade Federal de Sao Carlos, SP (Brazil). Dept. de Quimica]. E-mail: agcorrea@power.ufscar.br; Castilho, Marcelo S.; Oliva, Glaucius [Sao Paulo Univ., Sao Carlos, SP (Brazil). Inst. de Fisica

    2005-07-15

    Chagas' disease, caused by Trypanosoma cruzi, is endemic in 15 countries in Latin America. In this work a library of 38 coumarins was prepared in solution phase and evaluated against T. cruzi glycolytic enzyme glyceraldehyde-3-phosphate-dehydrogenase (gGAPDH). The synthetic route was based on the Knoevenagel condensation of different 2-hydroxybenzaldehydes with Meldrum's acid or diethyl malonate, followed by O-alkylation and/or transesterification reactions. Among the prepared coumarins, the best values obtained to inhibit 50% of the enzymatic activity range from 80 to 130 {mu}M. (author)

  1. A new bianthron glycoside as inhibitor of Trypanosoma cruzi glyceraldehyde 3-phosphate dehydrogenase activity

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Edangelo M.S. de; Silva, Maria G.V. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Analitica e Fisico-Quimica; Wiggers, Helton J.; Montanari, Carlos A. [Universidade de Sao Paulo (USP), SP (Brazil). Inst. de Quimica; Braz-Filho, Raimundo [Universidade Estadual do Norte Fluminense, Campos dos Goytacazes, RJ, (Brazil). Setor de Quimica de Produtos Naturais; Andricopulo, Adriano D. [Universidade de Sao Paulo (USP), Sao Carlos SP (Brazil). Inst. de Fisica

    2009-07-01

    A phytochemical investigation of the ethanolic extract of stalks of Senna martiana Benth. (Leguminoseae), native specie of northeast Brazil, resulted in the isolation and spectroscopic characterization of a new bianthrone glycoside, martianine 1 (10,10'-il-chrysophanol-10-oxi- 10,10'-bi-glucosyl). Its identification was established by HRMS, IR and 2D NMR experiments. The evaluation of martianine trypanocidal activity was carried out against gliceraldehyde 3-phosphate dehydrogenase enzyme from Trypanosoma cruzi. Its inhibitory constant (K{sub i}) is in the low micromolar concentration and it was determined by isothermal titration calorimetry to be 27.3 +-2.47 {mu}mol L{sup -1}. The non-competitive mechanism is asserted to be putative of the mode of action martianine displays against T. cruzi GAPDH. Results show that martianine has a great potential to become new lead molecule by inhibiting this key enzyme and for the development of new drugs against Chagas disease. (author)

  2. Secondary Metabolites from Vietnamese Marine Invertebrates with Activity against Trypanosoma brucei and T. cruzi

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    Nguyen Phuong Thao

    2014-06-01

    Full Text Available Marine-derived natural products from invertebrates comprise an extremely diverse and promising source of the compounds from a wide variety of structural classes. This study describes the discovery of five marine natural products with activity against Trypanosoma species by natural product library screening using whole cell in vitro assays. We investigated the anti-trypanosomal activity of the extracts from the soft corals and echinoderms living in Vietnamese seas. Of the samples screened, the methanolic extracts of several marine organisms exhibited potent activities against cultures of Trypanosoma brucei and T. cruzi (EC50 < 5.0 μg/mL. Among the compounds isolated from these extracts, laevigatol B (1 from Lobophytum crassum and L. laevigatum, (24S-ergost-4-ene-3-one (2 from Sinularia dissecta, astropectenol A (3 from Astropecten polyacanthus, and cholest-8-ene-3β,5α,6β,7α-tetraol (4 from Diadema savignyi showed inhibitory activity against T. brucei with EC50 values ranging from 1.57 ± 0.14 to 14.6 ± 1.36 μM, relative to the positive control, pentamidine (EC50 = 0.015 ± 0.003 μM. Laevigatol B (1 and 5α-cholest-8(14-ene-3β,7α-diol (5 exhibited also significant inhibitory effects on T. cruzi. The cytotoxic activity of the pure compounds on mammalian cells was also assessed and found to be insignificant in all cases. This is the first report on the inhibitory effects of marine organisms collected in Vietnamese seas against Trypanosoma species responsible for neglected tropical diseases.

  3. Assessment of the anti-protozoal activity of crude Carica papaya seed extract against Trypanosoma cruzi.

    Science.gov (United States)

    Jiménez-Coello, Matilde; Guzman-Marín, Eugenia; Ortega-Pacheco, Antonio; Perez-Gutiérrez, Salud; Acosta-Viana, Karla Y

    2013-10-11

    In order to determine the in vivo activity against the protozoan Trypanosoma cruzi, two doses (50 and 75 mg/kg) of a chloroform extract of Carica papaya seeds were evaluated compared with a control group of allopurinol. The activity of a mixture of the three main compounds (oleic, palmitic and stearic acids in a proportion of 45.9% of oleic acid, 24.1% of palmitic and 8.52% of stearic acid previously identified in the crude extract of C. papaya was evaluated at doses of 100, 200 and 300 mg/kg. Both doses of the extracts were orally administered for 28 days. A significant reduction (p papaya extract in comparison with the positive control group (allopurinol 8.5 mg/kg). Parasitemia in animals treated with the fatty acids mixture was also significantly reduced (p papaya (from ripe fruit) are able to reduce the number of parasites from both parasite stages, blood trypomastigote and amastigote (intracellular stage).

  4. Search for a platelet-activating factor receptor in the Trypanosoma cruzi proteome: a potential target for Chagas disease chemotherapy

    Directory of Open Access Journals (Sweden)

    Daniel Fábio Kawano

    2011-12-01

    Full Text Available Chagas disease (CD causes the highest burden of parasitic diseases in the Western Hemisphere and is therefore a priority for drug research and development. Platelet-activating factor (PAF causes the CD parasite Trypanosoma cruzi to differentiate, which suggests that the parasite may express PAF receptors. Here, we explored the T. cruzi proteome for PAF receptor-like proteins. From a total of 23,000 protein sequences, we identified 29 hypothetical proteins that are predicted to have seven transmembrane domains (TMDs, which is the main characteristic of the G protein-coupled receptors (GPCRs, including the PAF receptor. The TMDs of these sequences were independently aligned with domains from 25 animal PAF receptors and the sequences were analysed for conserved residues. The conservation score mean values for the TMDs of the hypothetical proteins ranged from 31.7-44.1%, which suggests that if the putative T. cruzi PAF receptor is among the sequences identified, the TMDs are not highly conserved. These results suggest that T. cruzi contains several GPCR-like proteins and that one of these GPCRs may be a PAF receptor. Future studies may further validate the PAF receptor as a target for CD chemotherapy.

  5. Resveratrol inhibits Trypanosoma cruzi arginine kinase and exerts a trypanocidal activity.

    Science.gov (United States)

    Valera Vera, Edward A; Sayé, Melisa; Reigada, Chantal; Damasceno, Flávia S; Silber, Ariel M; Miranda, Mariana R; Pereira, Claudio A

    2016-06-01

    Arginine kinase catalyzes the reversible transphosphorylation between ADP and phosphoarginine which plays a critical role in the maintenance of cellular energy homeostasis. Arginine kinase from the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, meets the requirements to be considered as a potential therapeutic target for rational drug design including being absent in its mammalian hosts. In this study a group of polyphenolic compounds was evaluated as potential inhibitors of arginine kinase using molecular docking techniques. Among the analyzed compounds with the lowest free binding energy to the arginine kinase active site (market price; and (3) has as a well-defined target enzyme which is absent in the mammalian host, it is a promising compound as a trypanocidal drug for Chagas disease. PMID:26976067

  6. Derivatives of Dictyostelium discoideum differentiation-inducing factor-3 suppress the activities of Trypanosoma cruzi in vitro and in vivo.

    Science.gov (United States)

    Nakajima-Shimada, Junko; Hatabu, Toshimitsu; Hosoi, Yukari; Onizuka, Yoko; Kikuchi, Haruhisa; Oshima, Yoshiteru; Kubohara, Yuzuru

    2013-06-01

    Chagas disease (human American trypanosomiasis), which is caused by the protozoan parasite Trypanosoma cruzi, is responsible for numerous deaths each year; however, established treatments for the disease are limited. Differentiation-inducing factor-1 (DIF-1) and DIF-3 are chlorinated alkylphenones originally found in the cellular slime mold Dictyostelium discoideum that have been shown to possess pharmacological activities. Here, we investigated the effects of DIF-3 derivatives on the infection rate and growth of T. cruzi by using an in vitro assay system utilizing host human fibrosarcoma HT1080 cells. Certain DIF-3 derivatives, such as butoxy-DIF-3 (Bu-DIF-3), at micro-molar levels strongly suppressed both the infection rate and growth of T. cruzi in HT1080 cells and exhibited little toxicity for HT1080 cells. For example, the IC50 of DIF-3 and Bu-DIF-3 versus the growth of T. cruzi in HT1080 cells were 3.95 and 0.72μM, respectively, and the LD50 of the two compounds versus HT1080 cells were both greater than 100μM. We also examined the effects of DIF-3 and Bu-DIF-3 on T. cruzi activity in C57BL/6 mice. Intraperitoneally administered Bu-DIF-3 (50mg/kg) significantly suppressed the number of trypomastigotes in blood with no apparent adverse effects. These results strongly suggest that DIF-3 derivatives could be new lead compounds in the development of anti-trypanosomiasis drugs. PMID:23511088

  7. Efecto del aceite esencial de Aloysia triphylla britton (cedrón) sobre el Trypanosoma cruzi en ratones The effect of the essential oil from Aloysia triphylla britton (lemon verbena) on Trypanosoma cruzi in mice

    OpenAIRE

    Juan Rojas; Olga Palacios; Sergio Ronceros

    2012-01-01

    Objetivos. Determinar la actividad anti-Trypanosoma cruzi in vivo del aceite esencial de Aloysia triphylla en ratones. Materiales y Métodos. Los animales fueron asignados aleatoriamente a los siguientes grupos (n = 15 por grupo): infectados y no tratados (G1), infectados y tratados con benznidazol 100 mg/kg (G2), infectados y tratados con aceite esencial de Aloysia triphylla 100 mg/kg (G3), infectados y tratados con aceite esencial de Aloysia triphylla 250 mg/kg (G4); no infectados y no trata...

  8. In vitro investigation of Brazilian Cerrado plant extract activity against Plasmodium falciparum, Trypanosoma cruzi and T. brucei gambiense.

    Science.gov (United States)

    Charneau, Sébastien; de Mesquita, Mariana Laundry; Bastos, Izabela Marques Dourado; Santana, Jaime Martins; de Paula, José Elias; Grellier, Philippe; Espindola, Laila Salmen

    2016-06-01

    The threatened Brazilian Cerrado biome is an important biodiversity hotspot but still few explored that constitutes a potential reservoir of molecules to treat infectious diseases. We selected eight Cerrado plant species for screening against the erythrocytic stages of Plasmodium falciparum, human intracellular stages of Trypanosoma cruzi and bloodstream forms of T. brucei gambiense, and for their cytotoxicity upon the rat L6-myoblast cell line. Bioassays were performed with 37 hexane, ethyl acetate and ethanol extracts prepared from different plant organs. Activities against parasites were observed for 24 extracts: 9 with anti-P. falciparum, 4 with anti-T. cruzi and 11 with anti-T. brucei gambiense activities. High anti-protozoal activity (IC50 values knowledge essential for Cerrado conservation and sustainable development. PMID:26222897

  9. Caspase-8 activity is part of the BeWo trophoblast cell defense mechanisms against Trypanosoma cruzi infection.

    Science.gov (United States)

    Carrillo, Ileana; Droguett, Daniel; Castillo, Christian; Liempi, Ana; Muñoz, Lorena; Maya, Juan Diego; Galanti, Norbel; Kemmerling, Ulrike

    2016-09-01

    Congenital Chagas disease is caused by the protozoan parasite Trypanosoma cruzi that must cross the placental barrier during transmission. The trophoblast constitutes the first tissue in contact with the maternal-blood circulating parasite. Importantly, the congenital transmission rates are low, suggesting the presence of local placental defense mechanisms. Cellular proliferation and differentiation as well as apoptotic cell death are induced by the parasite and constitute part of the epithelial turnover of the trophoblast, which has been suggested to be part of those placental defenses. On the other hand, caspase-8 is an essential molecule in the modulation of trophoblast turnover by apoptosis and by epithelial differentiation. As an approach to study whether T. cruzi induced trophoblast turnover and infection is mediated by caspase-8, we infected BeWo cells (a trophoblastic cell line) with the parasite and determined in the infected cells the expression and enzymatic activity of caspase-8, DNA synthesis (as proliferation marker), β-human chorionic gonadotropin (β-hCG) (as differentiation marker) and activity of Caspase-3 (as apoptotic death marker). Parasite load in BeWo cells was measured by DNA quantification using qPCR and cell counting. Our results show that T. cruzi induces caspase-8 activity and that its inhibition increases trophoblast cells infection while decreases parasite induced cellular differentiation and apoptotic cell death, but not cellular proliferation. Thus, caspase-8 activity is part of the BeWo trophoblast cell defense mechanisms against T. cruzi infection. Together with our previous results, we suggest that the trophoblast turnover is part of local placental anti-parasite mechanisms. PMID:27328973

  10. A rapid method for testing in vivo the susceptibility of different strains of Trypanosoma cruzi to active chemotherapeutic agents

    Directory of Open Access Journals (Sweden)

    Leny S. Filardi

    1984-06-01

    Full Text Available A method is described which permits to determine in vivo an in a short period of time (4-6 hours the sensitivity of T. cruzo strains to known active chemotherapeutic agents. By using resistant- and sensitive T. cruzi stains a fairly good correlation was observed between the results obtained with this rapid method (which detects activity against the circulating blood forms and those obtained with long-term schedules which involve drug adminstration for at least 20 consecutive days and a prolonged period of assessment. This method may be used to characterize susceptibility to active drugs used clinically, provide infomation on the specific action against circulating trypomastigotes and screen active compounds. Differences in the natural susceptibility of Trypanosoma cruzi strains to active drugs have been already reported using different criteria, mostly demanding long-term study of the animal (Hauschka, 1949; Bock, Gonnert & Haberkorn, 1969; Brener, Costa & Chiari, 1976; Andrade & Figueira, 1977; Schlemper, 1982. In this paper we report a method which detects in 4-6 hours the effect of drugs on bloodstream forms in mice with established T. cruzi infections. The results obtained with this method show a fairly good correlation with those obtained by prolonged treatment schedules used to assess the action of drugs in experimental Chagas' disease and may be used to study the sensitivity of T. cruzi strains to active drugs.No presente trabalho descreve-se um metodo que permite determinar in vivo e em curto espaço de tempo (4-6 horas a sensibilidade de cepas de T. cruzi a agentes terapeuticos ativos na doença de Chagas. Usando-se cepas sensíveis e resistentes aos medicamentos foi possível observar uma boa correlação entre os resultados obtidos com o método rápido (que detecta atividade contra as formas circulantes do parasita e aqueles obtidos com esquema de acao prolongada que envolve a administração da droga por 20 dias e posterior avalia

  11. An abietane diterpene from Salvia cuspidata and some new derivatives are active against Trypanosoma cruzi.

    Science.gov (United States)

    Lozano, E S; Spina, R M; Tonn, C E; Sosa, M A; Cifuente, D A

    2015-12-01

    The Plant Kingdom is an excellent source for obtaining natural compounds with antiprotozoal activity. In the present work, we studied the effect of the diterpene 12-hydroxy-11,14-diketo-6,8,12-abietatrien-19,20-olide (HABTO) obtained from the aerial parts of Salvia cuspidata on Trypanosoma cruzi epimastigotes. This compound was found to inhibit parasite growth even at low concentrations (IC50 5 μg/mL) and with low toxicity on mammalian cells. In addition, this diterpene induced an intense vacuolization within the parasites. In order to obtain analogs with greater lipophilicity, chemical modifications on the enol moiety were carried out to obtain the acetyl (AABTO), the sylil (SABTO) and the allyl (ALLABTO) derivatives. We observed that the SABTO was the most effective one on the parasites, and the effect could be attributed to a greater lipophilicity of this compound. Taking into account these data we conclude that the increase of lipophilicity by chemical modifications is an adequate strategy for improving the trypanocidal activity of this kind abietane diterpenes.

  12. Assessment of the Anti-Protozoal Activity of Crude Carica papaya Seed Extract against Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Karla Y. Acosta-Viana

    2013-10-01

    Full Text Available In order to determine the in vivo activity against the protozoan Trypanosoma cruzi, two doses (50 and 75 mg/kg of a chloroform extract of Carica papaya seeds were evaluated compared with a control group of allopurinol. The activity of a mixture of the three main compounds (oleic, palmitic and stearic acids in a proportion of 45.9% of oleic acid, 24.1% of palmitic and 8.52% of stearic acid previously identified in the crude extract of C. papaya was evaluated at doses of 100, 200 and 300 mg/kg. Both doses of the extracts were orally administered for 28 days. A significant reduction (p < 0.05 in the number of blood trypomastigotes was observed in animals treated with the evaluated doses of the C. papaya extract in comparison with the positive control group (allopurinol 8.5 mg/kg. Parasitemia in animals treated with the fatty acids mixture was also significantly reduced (p < 0.05, compared to negative control animals. These results demonstrate that the fatty acids identified in the seed extracts of C. papaya (from ripe fruit are able to reduce the number of parasites from both parasite stages, blood trypomastigote and amastigote (intracellular stage.

  13. Performance Assessment of Four Chimeric Trypanosoma cruzi Antigens Based on Antigen-Antibody Detection for Diagnosis of Chronic Chagas Disease.

    Science.gov (United States)

    Santos, Fred Luciano Neves; Celedon, Paola Alejandra Fiorani; Zanchin, Nilson Ivo Tonin; Brasil, Tatiana de Arruda Campos; Foti, Leonardo; Souza, Wayner Vieira de; Silva, Edmilson Domingos; Gomes, Yara de Miranda; Krieger, Marco Aurélio

    2016-01-01

    The performance of serologic tests in chronic Chagas disease diagnosis largely depends on the type and quality of the antigen preparations that are used for detection of anti-Trypanosoma cruzi antibodies. Whole-cell T. cruzi extracts or recombinant proteins have shown variation in the performance and cross-reactivity. Synthetic chimeric proteins comprising fragments of repetitive amino acids of several different proteins have been shown to improve assay performances to detect Chagasic infections. Here, we describe the production of four chimeric T. cruzi proteins and the assessment of their performance for diagnostic purposes. Circular Dichroism spectra indicated the absence of well-defined secondary structures, while polydispersity evaluated by Dynamic Light Scattering revealed only minor aggregates in 50 mM carbonate-bicarbonate (pH 9.6), demonstrating that it is an appropriate buffering system for sensitizing microplates. Serum samples from T. cruzi-infected and non-infected individuals were used to assess the performance of these antigens for detecting antibodies against T. cruzi, using both enzyme-linked immunosorbent assay and a liquid bead array platform. Performance parameters (AUC, sensitivity, specificity, accuracy and J index) showed high diagnostic accuracy for all chimeric proteins for detection of specific anti-T. cruzi antibodies and differentiated seropositive individuals from those who were seronegative. Our data suggest that these four chimeric proteins are eligible for phase II studies. PMID:27517281

  14. Seroprevalencia de la infección por Trypanosoma cruzi y factores asociados en un área endémica de Venezuela

    OpenAIRE

    Rafael Bonfante-Cabarcas; Claudina Rodríguez-Bonfante; Belkys Oviol Vielma; Douglas García; Alexander Mogollón Saldivia; Elis Aldana; Juan Luis Concepción Curvelo

    2011-01-01

    Determinamos factores de riesgo asociados a la seropositividad para anticuerpos anti-Trypanosoma cruzi en 26 poblaciones rurales, 905 viviendas, 2.156 individuos y 333 caninos en el Estado Lara, Venezuela. La seropositividad fue determinada mediante ELISA y MABA. Los datos fueron obtenidos mediante encuestas entomológicas, demográficas y médicas. Los factores de riesgo fueron establecidos mediante regresión logística binaria. La seroprevalencia humana fue de 7,24% y la canina 6,9%. La seropos...

  15. Crystal Structures of Trypanosoma cruzi UDP-Galactopyranose Mutase Implicate Flexibility of the Histidine Loop in Enzyme Activation

    Energy Technology Data Exchange (ETDEWEB)

    Dhatwalia, Richa; Singh, Harkewal; Oppenheimer, Michelle; Sobrado, Pablo; Tanner, John J. (Virginia Tech); (UMC)

    2012-11-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. Here we report crystal structures of the galactofuranose biosynthetic enzyme UDP-galactopyranose mutase (UGM) from T. cruzi, which are the first structures of this enzyme from a protozoan parasite. UGM is an attractive target for drug design because galactofuranose is absent in humans but is an essential component of key glycoproteins and glycolipids in trypanosomatids. Analysis of the enzyme-UDP noncovalent interactions and sequence alignments suggests that substrate recognition is exquisitely conserved among eukaryotic UGMs and distinct from that of bacterial UGMs. This observation has implications for inhibitor design. Activation of the enzyme via reduction of the FAD induces profound conformational changes, including a 2.3 {angstrom} movement of the histidine loop (Gly60-Gly61-His62), rotation and protonation of the imidazole of His62, and cooperative movement of residues located on the si face of the FAD. Interestingly, these changes are substantially different from those described for Aspergillus fumigatus UGM, which is 45% identical to T. cruzi UGM. The importance of Gly61 and His62 for enzymatic activity was studied with the site-directed mutant enzymes G61A, G61P, and H62A. These mutations lower the catalytic efficiency by factors of 10-50, primarily by decreasing k{sub cat}. Considered together, the structural, kinetic, and sequence data suggest that the middle Gly of the histidine loop imparts flexibility that is essential for activation of eukaryotic UGMs. Our results provide new information about UGM biochemistry and suggest a unified strategy for designing inhibitors of UGMs from the eukaryotic pathogens.

  16. Defining the role of a FYVE domain in the localization and activity of a cAMP phosphodiesterase implicated in osmoregulation in Trypanosoma cruzi

    Science.gov (United States)

    Schoijet, Alejandra C.; Miranda, Kildare; Medeiros, Lia Carolina Soares; de Souza, Wanderley; Flawiá, Mirtha M.; Torres, Héctor N.; Pignataro, Omar P.; Docampo, Roberto; Alonso, Guillermo D.

    2010-01-01

    Summary Intracellular levels of cyclic nucleotide second messengers are regulated predominantly by a large superfamily of phosphodiesterases. Trypanosoma cruzi, the causative agent of Chagas disease, encodes four different phosphodiesterase (PDE) families. One of these PDEs, T. cruzi phosphodiesterase C2 (TcrPDEC2) has been characterized as a FYVE-domain containing protein. Here, we report a novel role for TcrPDEC2 in osmoregulation in T. cruzi and reveal the relevance of its FYVE domain. Our data show that treatment of epimastigotes with TcrPDEC2 inhibitors improves their regulatory volume decrease, whereas cells overexpressing this enzyme are unaffected by the same inhibitors. Consistent with these results, TcrPDEC2 localizes to the contractile vacuole complex, showing strong labeling in the region corresponding to the spongiome. Furthermore, transgenic parasites overexpressing a truncated version of TcrPDEC2 without the FYVE domain show a failure in its targeting to the contractile vacuole complex and a marked decrease in phosphodiesterase activity, supporting the importance of this domain to the localization and activity of TcrPDEC2. Taking together, the results here presented are consistent with the importance of the cyclic AMP signaling pathway in regulatory volume decrease and implicate TcrPDEC2 as a specifically localized phosphodiesterase involved in osmoregulation in T. cruzi. PMID:21166893

  17. Plants used in Guatemala for the treatment of protozoal infections: II. Activity of extracts and fractions of five Guatemalan plants against Trypanosoma cruzi.

    Science.gov (United States)

    Berger, I; Barrientos, A C; Cáceres, A; Hernández, M; Rastrelli, L; Passreiter, C M; Kubelka, W

    1998-09-01

    The activities of crude plant extracts of five plants popularly used in Guatemala against bacterial and protozoal infections and some of their fractions have been evaluated against the trypomastigote and epimastigote forms of Trypanosoma cruzi in vitro. The most active fraction of Neurolaena lobata has also been screened in vivo. Main in vitro activities against trypomastigotes have been observed for the hexane and ethanol extracts of N. lobata (Asteraceae). Both extracts were also active against epimastigotes, whereas all other extracts tested had no effect on epimastigotes. For the hexane extracts of Petiveria alliacea (Phytolaccaceae) and Tridax procumbens (Asteraceae) a marked inhibition of trypomastigotes has been found. Also the ethanol extracts of Byrsonima crassifolia (Malpighiaceae) leafs and Gliricidia sepium (Papilionaceae) bark showed some trypanocidal activity. Fraction 2 of the ethanol extract of N. lobata was highly active against T. cruzi as well in vitro as in vivo. The chloroforme fraction of P. alliacea showed a high inhibition of trypomastigotes in vitro. Also three fractions of the active extract of B. crassifolia inhibited T. cruzi trypomastigotes. No fraction of G. sepium bark extract showed a marked trypanocidal activity. PMID:9741882

  18. Comparison of the C-mediating killing activity and C-activating properties of mouse monoclonal and polyclonal antibodies against Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    T. L. Kipnis

    1992-01-01

    Full Text Available A Mouse polyclonal antiserum against Trypanosoma cruzi or its IgG and IgM fractions and five monoclonal antibodies (two IgM, two IgG1 and one IgG2a recognize and combine with membrane components of trypomastigote forms of the parasite as revealed by immunofluorescence. Although all these antibodies sensitize trypomastigotes and prepare them to activate the complement (C system, as measured by consumption of total C, C4, B and C3, only the polyclonal antiserum or its IgG, IgM and Fabμ fragments were able to induce trypanosome lysis by the alternative C pathway.

  19. Importance of the CCR5-CCL5 axis for mucosal Trypanosoma cruzi protection and B cell activation.

    Science.gov (United States)

    Sullivan, Nicole L; Eickhoff, Christopher S; Zhang, Xiuli; Giddings, Olivia K; Lane, Thomas E; Hoft, Daniel F

    2011-08-01

    Trypanosoma cruzi is an intracellular parasite and the causative agent of Chagas disease. Previous work has shown that the chemokine receptor CCR5 plays a role in systemic T. cruzi protection. We evaluated the importance of CCR5 and CCL5 for mucosal protection against natural oral and conjunctival T. cruzi challenges. T. cruzi-immune CCR5(-/-) and wild-type C57BL/6 mice were generated by repeated infectious challenges with T. cruzi. CCR5(-/-) and wild-type mice developed equivalent levels of cellular, humoral, and protective mucosal responses. However, CCR5(-/-)-immune mice produced increased levels of CCL5 in protected gastric tissues, suggesting compensatory signaling through additional receptors. Neutralization of CCL5 in CCR5(-/-)-immune mice resulted in decreased mucosal inflammatory responses, reduced T. cruzi-specific Ab-secreting cells, and significantly less mucosal T. cruzi protection, confirming an important role for CCL5 in optimal immune control of T. cruzi replication at the point of initial mucosal invasion. To investigate further the mechanism responsible for mucosal protection mediated by CCL5-CCR5 signaling, we evaluated the effects of CCL5 on B cells. CCL5 enhanced proliferation and IgM secretion in highly purified B cells triggered by suboptimal doses of LPS. In addition, neutralization of endogenous CCL5 inhibited B cell proliferation and IgM secretion during stimulation of highly purified B cells, indicating that B cell production of CCL5 has important autocrine effects. These findings demonstrate direct effects of CCL5 on B cells, with significant implications for the development of mucosal adjuvants, and further suggest that CCL5 may be important as a general B cell coactivator.

  20. In Vitro and In Vivo Activities of E5700 and ER-119884, Two Novel Orally Active Squalene Synthase Inhibitors, against Trypanosoma cruzi

    Science.gov (United States)

    Urbina, Julio A.; Concepcion, Juan Luis; Caldera, Aura; Payares, Gilberto; Sanoja, Cristina; Otomo, Takeshi; Hiyoshi, Hironobu

    2004-01-01

    Chagas' disease is a serious public health problem in Latin America, and no treatment is available for the prevalent chronic stage. Its causative agent, Trypanosoma cruzi, requires specific endogenous sterols for survival, and we have recently demonstrated that squalene synthase (SQS) is a promising target for antiparasitic chemotherapy. E5700 and ER-119884 are quinuclidine-based inhibitors of mammalian SQS that are currently in development as cholesterol- and triglyceride-lowering agents in humans. These compounds were found to be potent noncompetitive or mixed-type inhibitors of T. cruzi SQS with Ki values in the low nanomolar to subnanomolar range in the absence or presence of 20 μM inorganic pyrophosphate. The antiproliferative 50% inhibitory concentrations of the compounds against extracellular epimastigotes and intracellular amastigotes were ca. 10 nM and 0.4 to 1.6 nM, respectively, with no effects on host cells. When treated with these compounds at the MIC, all of the parasite's sterols disappeared from the parasite cells. In vivo studies indicated that E5700 was able to provide full protection against death and completely arrested the development of parasitemia when given at a concentration of 50 mg/kg of body weight/day for 30 days, while ER-119884 provided only partial protection. This is the first report of an orally active SQS inhibitor that is capable of providing complete protection against fulminant, acute Chagas' disease. PMID:15215084

  1. Prevalencia de anticuerpos para Trypanosoma cruzi en caninos de dos municipios endémicos de Boyacá

    Directory of Open Access Journals (Sweden)

    Diego Manrique Abril

    2012-04-01

    Full Text Available Objetivo. evaluar la prevalencia de anticuerpos anti Trypanosoma cruzi (T. cruzi en una muestra de caninos domésticos residentes en dos municipios endémicos. Materiales y métodos. Se tomaron muestras séricas de 20 caninos procedentes de hogares donde residen mujeres gestantes seropositivas y 40 perros habitantes de hogares de mujeres gestantes seronegativas en Miraflores y Moniquira, Boyacá. El análisis se realizó mediante prueba diagnóstica rápida dipstick de InBios. Resultados. Se encontró prevalencia del 16.7% en Moniquirá y del 13.3% Miraflores respectivamente con una prevalencia general del 15% en los dos municipios. Se halló riesgo 3 veces mayor de que ocurra la infección en caninos, en los hogares donde residen gestantes seropositivas; además la infestación por pulgas y garrapatas en el animal, hábitat cercano a la vivienda, se relacionan con mayor seropositividad en el canino. Conclusiones. La raza, el sexo, la presencia de aves en la casa y al examen clínico general son considerados factores pronósticos en en la infección por Trypanosoma cruzi en caninos. Como factores protectores se identificó la desparasitación y vacunación de los animales.

  2. Immunodiagnosis of Trypanosoma cruzi (Chagas' Disease Infection in Naturally Infected Dogs

    Directory of Open Access Journals (Sweden)

    Lauricella MA

    1998-01-01

    Full Text Available This study reports on the standardization of an enzyme-linked immunosorbent assay (ELISA for detecting specific antibodies anti-Trypanosoma cruzi in naturally infected dogs. Sera from 182 mongrel dogs of all ages residing in four rural villages in Santiago del Estero, Argentina, were collected in November 1994 and preserved in buffered neutral glycerin. All sera were tested by indirect hemagglutination test (IHAT, indirect immunofluorescence test (IFAT, and ELISA using the flagellar fraction of T. cruzi as antigen. Dog sera from an area without vectorial transmission were used to calculate ELISA specificity and cut-off value. Eighty-six percent of sera had concordant results for all tests. All sera reactive for IHAT and IFAT were also reactive for ELISA, except in one case. Sera tested by ELISA when diluted 1:200 allowed a clearer division between non-reactive and reactive sera than when 1:100 with greater agreement among serologic techniques. The specificity of ELISA was 96.2%. Among 34 adult dogs with a positive xenodiagnosis, sensitivity was 94% both for ELISA and IFAT. ELISA is the first choice for screening purposes and one of the pair of techniques recommended for diagnostic studies in dog populations

  3. Macrophage activation and histopathological findings in Calomys callosus and Swiss mice infected with several strains of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Monamaris Marques Borges

    1992-12-01

    Full Text Available Peritoneal macrophage activation as measured by H2O2 release and histopathology was compared between Swiss mice and Calomys callosus, a wild rodent, reservoir of Trypanosoma cruzi, during the course of infection with four strains of this parasite. In mice F and Y strain infections result in high parasitemia and mortality while with silvatic strains Costalimai and M226 parasitemia is sub-patent, with very low mortality. H2O2 release peaked at 33,6 and 59 nM/2 x 10(elevado a sexta potência cells for strains Y and F, respectively, 48 and 50 nM/2 x 10 (elevado a sexta potência for strains Costalimai and M226, at different days after infection. Histopathological findings of myositis, myocarditis, necrotizing artheritis and abscence of macrophage parasitism were foud for strains F and Costalimai. Y strain infection presented moderate myocarditis and myositis, with parasites multiplying within macrophages. In C. callosus all four strains resulted in patent parasitemia wich was eventually overcome, with scarce mortality. H2O2 release for strains Y or F was comparable to that of mice-peaks of 27 and 53 nM/2 x 10 (elevado a sexta potência cells, with lower values for strains Costalimai and M226 - 16.5 and 4.6 nM/2 x 10(elevado a sexta potênciacells, respectively. Histopathological lesions with Y and F strain injected animals were comparable to those of mice at the onset of infections; they subsided completely at the later stages with Y strain and partially with F strain infected C. callosus. In Costalimai infected C. callosus practically no histopathological alterations were observed.

  4. Modulation of the catalytic activity of cruzipain, the major cysteine proteinase from Trypanosoma cruzi, by temperature and pH.

    Science.gov (United States)

    Salvati, L; Mattu, M; Polticelli, F; Tiberi, F; Gradoni, L; Venturini, G; Bolognesi, M; Ascenzi, P

    2001-06-01

    Cysteine proteinases are relevant to several aspects of the parasite life cycle and of parasite-host relationships. Here, a quantitative investigation of the effect of temperature and pH on the total substrate inhibition of cruzipain, the major papain-like cysteine proteinase from Trypanosoma cruzi, is reported. Values of the apparent catalytic and inhibition parameters Km, Vmax, Vmax/Km, and K(i) for the cruzipain-catalysed hydrolysis of N-alpha-benzyloxycarbonyl-L-phenylalanyl-L-arginine-(7-amino-4-methylcoumarin) (Z-Phe-Arg-AMC) and azocasein were determined between 10.0 degrees C and 40.0 degrees C and between pH 4.5 and 8.5. Values of Km were independent of temperature and pH, whereas values of Vmax, Vmax/Km, and K(i) were temperature-dependent and pH-dependent. Over the whole pH range explored, values of logVmax, log(Vmax/Km), and logK(i) increased linearly with respect to T(-1). Values of Vmax and Vmax/Km were affected by the acid-base equilibrium of one temperature-independent ionizing group (i.e. pK(unl)' = pK(lig)' = 5.7 +/- 0.1, at 25.0 degrees C). Moreover, values of K(i) were affected by the alkaline pK shift of one ionizing group of active cruzipain (from pK(unl)" = 5.7 +/- 0.1 to pK(lig)" = 6.1 +/- 0.1, at 25.0 degrees C) upon Z-Phe-Arg-AMC binding. Values of logK(unl)', logK(lig)', and logK(lig)" were temperature-independent. Conversely, values of logK(unl)" were linearly dependent on T(-1). As a whole, total substrate inhibition of cruzipain decreased with increasing temperature and pH. These data suggest that both synthetic and protein substrates can bind to the unique active centre of cruzipain either productively or following a binding mode which results in enzyme inhibition. However, allosteric effect(s) cannot be excluded.

  5. In Vivo Antiprotozoal Activity of the Chloroform Extract from Carica papaya Seeds against Amastigote Stage of Trypanosoma cruzi during Indeterminate and Chronic Phase of Infection

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    Matilde Jimenez-Coello

    2014-01-01

    Full Text Available In order to evaluate the antiprotozoal activity of the chloroform extract of Carica papaya seeds during the subacute and chronic phase of infection of Trypanosoma cruzi, doses of 50 and 75 mg/kg were evaluated during the subacute phase, including a mixture of their main components (oleic, palmitic, and stearic acids. Subsequently, doses of 50 and 75 mg/kg in mice during the chronic phase of infection (100 dpi were also evaluated. It was found that chloroform extract was able to reduce the amastigote nests numbers during the subacute phase in 55.5 and 69.7% (P > 0.05 as well as in 56.45% in animals treated with the mixture of fatty acids. Moreover, the experimental groups treated with 50 and 75 mg/kg during the chronic phase of the infection showed a significant reduction of 46.8 and 53.13% respectively (P < 0.05. It is recommended to carry out more studies to determine if higher doses of chloroformic extract or its administration in combination with other antichagasic drugs allows a better response over the intracellular stage of T. cruzi in infected animal models and determine if the chloroform extract of C. papaya could be considered as an alternative for treatment during the indeterminate and chronic phase of the infection.

  6. Structure-based approach to pharmacophore identification, in silico screening, and three-dimensional quantitative structure-activity relationship studies for inhibitors of Trypanosoma cruzi dihydrofolate reductase function

    Energy Technology Data Exchange (ETDEWEB)

    Schormann, N.; Senkovich, O.; Walker, K.; Wright, D.L.; Anderson, A.C.; Rosowsky, A.; Ananthan, S.; Shinkre, B.; Velu, S.; Chattopadhyay, D. (UAB); (Connecticut); (Southern Research); (DFCI)

    2009-07-10

    We have employed a structure-based three-dimensional quantitative structure-activity relationship (3D-QSAR) approach to predict the biochemical activity for inhibitors of T. cruzi dihydrofolate reductase-thymidylate synthase (DHFR-TS). Crystal structures of complexes of the enzyme with eight different inhibitors of the DHFR activity together with the structure in the substrate-free state (DHFR domain) were used to validate and refine docking poses of ligands that constitute likely active conformations. Structural information from these complexes formed the basis for the structure-based alignment used as input for the QSAR study. Contrary to indirect ligand-based approaches the strategy described here employs a direct receptor-based approach. The goal is to generate a library of selective lead inhibitors for further development as antiparasitic agents. 3D-QSAR models were obtained for T. cruzi DHFR-TS (30 inhibitors in learning set) and human DHFR (36 inhibitors in learning set) that show a very good agreement between experimental and predicted enzyme inhibition data. For crossvalidation of the QSAR model(s), we have used the 10% leave-one-out method. The derived 3D-QSAR models were tested against a few selected compounds (a small test set of six inhibitors for each enzyme) with known activity, which were not part of the learning set, and the quality of prediction of the initial 3D-QSAR models demonstrated that such studies are feasible. Further refinement of the models through integration of additional activity data and optimization of reliable docking poses is expected to lead to an improved predictive ability.

  7. Molecular characterization of Trypanosoma cruzi SAP proteins with host-cell lysosome exocytosis-inducing activity required for parasite invasion.

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    Tamiris Zanforlin

    Full Text Available BACKGROUND: To invade target cells, Trypanosoma cruzi metacyclic forms engage distinct sets of surface and secreted molecules that interact with host components. Serine-, alanine-, and proline-rich proteins (SAP comprise a multigene family constituted of molecules with a high serine, alanine and proline residue content. SAP proteins have a central domain (SAP-CD responsible for interaction with and invasion of mammalian cells by metacyclic forms. METHODS AND FINDINGS: Using a 513 bp sequence from SAP-CD in blastn analysis, we identified 39 full-length SAP genes in the genome of T. cruzi. Although most of these genes were mapped in the T. cruzi in silico chromosome TcChr41, several SAP sequences were spread out across the genome. The level of SAP transcripts was twice as high in metacyclic forms as in epimastigotes. Monoclonal (MAb-SAP and polyclonal (anti-SAP antibodies produced against the recombinant protein SAP-CD were used to investigate the expression and localization of SAP proteins. MAb-SAP reacted with a 55 kDa SAP protein released by epimastigotes and metacyclic forms and with distinct sets of SAP variants expressed in amastigotes and tissue culture-derived trypomastigotes (TCTs. Anti-SAP antibodies reacted with components located in the anterior region of epimastigotes and between the nucleus and the kinetoplast in metacyclic trypomastigotes. In contrast, anti-SAP recognized surface components of amastigotes and TCTs, suggesting that SAP proteins are directed to different cellular compartments. Ten SAP peptides were identified by mass spectrometry in vesicle and soluble-protein fractions obtained from parasite conditioned medium. Using overlapping sequences from SAP-CD, we identified a 54-aa peptide (SAP-CE that was able to induce host-cell lysosome exocytosis and inhibit parasite internalization by 52%. CONCLUSIONS: This study provides novel information about the genomic organization, expression and cellular localization of SAP

  8. Clinical Candidate VT-1161's Antiparasitic Effect In Vitro, Activity in a Murine Model of Chagas Disease, and Structural Characterization in Complex with the Target Enzyme CYP51 from Trypanosoma cruzi.

    Science.gov (United States)

    Hoekstra, William J; Hargrove, Tatiana Y; Wawrzak, Zdzislaw; da Gama Jaen Batista, Denise; da Silva, Cristiane F; Nefertiti, Aline S G; Rachakonda, Girish; Schotzinger, Robert J; Villalta, Fernando; Soeiro, Maria de Nazaré C; Lepesheva, Galina I

    2016-02-01

    A novel antifungal drug candidate, the 1-tetrazole-based agent VT-1161 [(R)-2-(2,4-difluorophenyl)-1,1-difluoro-3-(1H-tetrazol-1-yl)-1-{5-[4-(2,2,2-trifluoroethoxy)phenyl]pyridin-2-yl}propan-2-ol], which is currently in two phase 2b antifungal clinical trials, was found to be a tight-binding ligand (apparent dissociation constant [Kd], 24 nM) and a potent inhibitor of cytochrome P450 sterol 14α-demethylase (CYP51) from the protozoan pathogen Trypanosoma cruzi. Moreover, VT-1161 revealed a high level of antiparasitic activity against amastigotes of the Tulahuen strain of T. cruzi in cellular experiments (50% effective concentration, 2.5 nM) and was active in vivo, causing >99.8% suppression of peak parasitemia in a mouse model of infection with the naturally drug-resistant Y strain of the parasite. The data strongly support the potential utility of VT-1161 in the treatment of Chagas disease. The structural characterization of T. cruzi CYP51 in complex with VT-1161 provides insights into the molecular basis for the compound's inhibitory potency and paves the way for the further rational development of this novel, tetrazole-based inhibitory chemotype both for antiprotozoan chemotherapy and for antifungal chemotherapy. PMID:26643331

  9. Trypanocidal activity of genotoxic concentration of benznidazole on epimastigote forms of Trypanosoma cruzi = Atividade tripanocida da concentração genotóxica do benzonidazol em formas epimastigotas de Trypanosoma cruzi

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    Edilson Nobuyoshi Kaneshima

    2012-10-01

    Full Text Available The genotoxicity of benznidazole at a concentration of 75 µM, used in the treatment of Chagas’ disease, has been recently reported. The present study evaluated the inhibitory effect of benznidazole on the growth of epimastigote forms of T. cruzi I and II by using genotoxic (75 µM and non-genotoxic (50 µM concentrations. To assess the growth rates of T. cruzi strains G2, A2.1A, CL, Y, and 2052, parasites in the epimastigote form were cultured in LIT medium for 192 h at 28ºC, with (50 and 75 µM and without (negative control benznidazole. Benznidazole at both concentrations inhibited all the strains, regardless of genetic group. In the 75 µM concentration, there was a significant decrease in the number of parasites inoculated at T0 after 96 h incubation. The results showed that although genotoxic and non-genotoxic doses of benznidazole inhibit the growth of the epimastigote forms of T. cruzi I and II, only the 75 µM dose seem to indicate a possible trypanocidal effect.O benzonidazol é um medicamento utilizado no tratamento da doença de Chagas, cuja genotoxicidade foi recentemente observada em concentrações a partir de 75 µM. O efeito inibitório do benzonidazol sobre o crescimento de formas epimastigotas de T. cruzi I e II foi avaliado no presente trabalho, utilizando-se concentrações genotóxica (75 µM e não genotóxica (50 µM deste medicamento. Para avaliação da taxa de crescimento das cepas G2, A2.1A, CL, Y e 2052, os parasitos na forma epimastigota foram cultivados em meio LIT, durante 192 horas, à 28 o C, tanto em presença de benzonidazol (50 e 75 µM, quanto em sua ausência (controle negativo. O efeito inibitório do benzonidazol, em ambas concentrações, foi observado para todas as cepas analisadas, independentemente do grupo genético a que pertençam. Na concentração de 75 µM, observou-se após 96 horas de incubação, redução significativa do número de parasitos inoculados no tempo zero (T0. Os resultados

  10. In vitro and in vivo studies of the antiparasitic activity of sterol 14α-demethylase (CYP51) inhibitor VNI against drug-resistant strains of Trypanosoma cruzi.

    Science.gov (United States)

    Soeiro, Maria de Nazaré Correia; de Souza, Elen Mello; da Silva, Cristiane França; Batista, Denise da Gama Jaen; Batista, Marcos Meuser; Pavão, Beatriz Philot; Araújo, Julianna Siciliano; Aiub, Claudia Alessandra Fortes; da Silva, Patrícia Bernardino; Lionel, Jessica; Britto, Constança; Kim, Kwangho; Sulikowski, Gary; Hargrove, Tatiana Y; Waterman, Michael R; Lepesheva, Galina I

    2013-09-01

    Chagas disease affects more than 10 million people worldwide, and yet, as it has historically been known as a disease of the poor, it remains highly neglected. Two currently available drugs exhibit severe toxicity and low effectiveness, especially in the chronic phase, while new drug discovery has been halted for years as a result of a lack of interest from pharmaceutical companies. Although attempts to repurpose the antifungal drugs posaconazole and ravuconazole (inhibitors of fungal sterol 14α-demethylase [CYP51]) are finally in progress, development of cheaper and more efficient, preferably Trypanosoma cruzi-specific, chemotherapies would be highly advantageous. We have recently reported that the experimental T. cruzi CYP51 inhibitor VNI cures with 100% survival and 100% parasitological clearance both acute and chronic murine infections with the Tulahuen strain of T. cruzi. In this work, we further explored the potential of VNI by assaying nitro-derivative-resistant T. cruzi strains, Y and Colombiana, in highly stringent protocols of acute infection. The data show high antiparasitic efficacy of VNI and its derivative (VNI/VNF) against both forms of T. cruzi that are relevant for mammalian host infection (bloodstream and amastigotes), with the in vivo potency, at 25 mg/kg twice a day (b.i.d.), similar to that of benznidazole (100 mg/kg/day). Transmission electron microscopy and reverse mutation tests were performed to explore cellular ultrastructural and mutagenic aspects of VNI, respectively. No mutagenic potential could be seen by the Ames test at up to 3.5 μM, and the main ultrastructural damage induced by VNI in T. cruzi was related to Golgi apparatus and endoplasmic reticulum organization, with membrane blebs presenting an autophagic phenotype. Thus, these preliminary studies confirm VNI as a very promising trypanocidal drug candidate for Chagas disease therapy. PMID:23774435

  11. The Trypanosoma cruzi protease cruzain mediates immune evasion.

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    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.

  12. Identification of the nicotinamide mononucleotide adenylyltransferase of Trypanosoma cruzi

    Science.gov (United States)

    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

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

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    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.

  14. Effects of organic solvents on the enzyme activity of Trypanosoma cruzi glyceraldehyde-3-phosphate dehydrogenase in calorimetric assays

    DEFF Research Database (Denmark)

    Wiggers, Henrik; Cheleski, J; Zottis, A;

    2007-01-01

    .0% for MeOH and up to 7.5% for DMSO. The results show that when GAPDH is assayed in the presence of DMSO (5%, v/v) using the ITC experiment, the enzyme exhibits approximately twofold higher activity than that of GAPDH with no cosolvent added. When MeOH (5%, v/v) is the cosolvent, the GAPDH activity......In drug discovery programs, dimethyl sulfoxide (DMSO) is a standard solvent widely used in biochemical assays. Despite the extensive use and study of enzymes in the presence of organic solvents, for some enzymes the effect of organic solvent is unknown. Macromolecular targets may be affected...... by the presence of different solvents in such a way that conformational changes perturb their active site structure accompanied by dramatic variations in activity when performing biochemical screenings. To address this issue, in this work we studied the effects of two organic solvents, DMSO and methanol (Me...

  15. Seroprevalencia de la infección por Trypanosoma cruzi y factores asociados en un área endémica de Venezuela

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    Rafael Bonfante-Cabarcas

    2011-10-01

    Full Text Available Determinamos factores de riesgo asociados a la seropositividad para anticuerpos anti-Trypanosoma cruzi en 26 poblaciones rurales, 905 viviendas, 2.156 individuos y 333 caninos en el Estado Lara, Venezuela. La seropositividad fue determinada mediante ELISA y MABA. Los datos fueron obtenidos mediante encuestas entomológicas, demográficas y médicas. Los factores de riesgo fueron establecidos mediante regresión logística binaria. La seroprevalencia humana fue de 7,24% y la canina 6,9%. La seropositividad estuvo asociada positivamente al Rhodnius prolixus, la edad, madre con antecedentes de Chagas, consumo de chimó, presencia de mamíferos y aves en la vivienda, desorden en el domicilio, y anexos de bajareque, nidos y cuevas en el peridomicilio. Negativamente con hábitos de consumo de tabaco y alcohol, antecedentes de cáncer y a depósitos en el peridomicilio. En conclusión, la enfermedad de Chagas en el área rural estudiada es un fenómeno remoto transmitida por R. prolixus y vía transplacentaria, asociada a hábitos socioculturales relacionados con la pobreza, a entornos selváticos y antecedentes médicos del huésped.

  16. Anion inhibition studies of the α-carbonic anhydrase from the protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas disease.

    Science.gov (United States)

    Pan, Peiwen; Vermelho, Alane Beatriz; Scozzafava, Andrea; Parkkila, Seppo; Capasso, Clemente; Supuran, Claudiu T

    2013-08-01

    The protozoan pathogen Trypanosoma cruzi, the causative agent of Chagas disease, encodes an α-class carbonic anhydrase (CA, EC 4.2.1.1), TcCA, which was recently shown to be crucial for its life cycle. Thiols, a class of strong TcCA inhibitors, were also shown to block the growth of the pathogen in vitro. Here we report the inhibition of TcCA by inorganic and complex anions and other molecules interacting with zinc proteins, such as sulfamide, sulfamic acid, phenylboronic/arsonic acids. TcCA was inhibited in the low micromolar range by iodide, cyanate, thiocyanate, hydrogensulfide and trithiocarbonate (KIs in the range of 44-93 μM), but the best inhibitor was diethyldithiocarbamate (KI=5 μM). Sulfamide showed an inhibition constant of 120 μM, but sulfamic acid was much less effective (KI of 10.6 mM). The discovery of diethyldithiocarbamate as a low micromolar TcCA inhibitor may be useful to detect leads for developing anti-Trypanosoma agents with a diverse mechanism of action compared to clinically used drugs (benznidazole, nifurtimox) for which significant resistance emerged. PMID:23790722

  17. Aspirin Modulates Innate Inflammatory Response and Inhibits the Entry of Trypanosoma cruzi in Mouse Peritoneal Macrophages

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    Aparecida Donizette Malvezi

    2014-01-01

    Full Text Available The intracellular protozoan parasite Trypanosoma cruzi causes Chagas disease, a serious disorder that affects millions of people in Latin America. Cell invasion by T. cruzi and its intracellular replication are essential to the parasite’s life cycle and for the development of Chagas disease. Here, we present evidence suggesting the involvement of the host’s cyclooxygenase (COX enzyme during T. cruzi invasion. Pharmacological antagonist for COX-1, aspirin (ASA, caused marked inhibition of T. cruzi infection when peritoneal macrophages were pretreated with ASA for 30 min at 37°C before inoculation. This inhibition was associated with increased production of IL-1β and nitric oxide (NO∙ by macrophages. The treatment of macrophages with either NOS inhibitors or prostaglandin E2 (PGE2 restored the invasive action of T. cruzi in macrophages previously treated with ASA. Lipoxin ALX-receptor antagonist Boc2 reversed the inhibitory effect of ASA on trypomastigote invasion. Our results indicate that PGE2, NO∙, and lipoxins are involved in the regulation of anti-T. cruzi activity by macrophages, providing a better understanding of the role of prostaglandins in innate inflammatory response to T. cruzi infection as well as adding a new perspective to specific immune interventions.

  18. Molecular and Cellular Mechanisms Involved in the Trypanosoma cruzi/Host Cell Interplay

    Science.gov (United States)

    Romano, Patricia Silvia; Cueto, Juan Agustín; Casassa, Ana Florencia; Vanrell, María Cristina; Gottlieb, Roberta A.; Colombo, María Isabel

    2013-01-01

    Summary The protozoan parasite Trypanosoma cruzi has a complex bi-ological cycle that involves vertebrate and invertebrate hosts. In mammals, the infective trypomastigote form of this parasite can invade several cell types by exploiting phagocytic-like or non-phagocytic mechanisms depending on the class of cell involved. Morphological studies showed that when trypomastigotes contact macrophages, they induce the formation of plasma membrane protrusions that differ from the canonical phagocytosis that occurs in the case of noninfective epimastigotes. In contrast, when trypomastigotes infect epithelial or muscle cells, the cell surface is minimally modified, suggesting the induction of a different class of process. Lysosomal-dependent or -independent T. cruzi invasion of host cells are two different models that describe the molecular and cellular events activated during parasite entry into nonphagocytic cells. In this context, we have previously shown that induction of autophagy in host cells before infection favors T. cruzi invasion. Furthermore, we demonstrate that autophagosomes and the autophagosomal protein LC3 are recruited to the T. cruzi entry sites and that the newly formed T. cruzi parasitophorous vacuole has characteristics of an autophagolysosome. This review summarizes the current knowledge of the molecular and cellular mechanisms of T. cruzi invasion in nonphagocytic cells. Based on our findings, we propose a new model in which T. cruzi takes advantage of the up-regulation of autophagy during starvation to increase its successful colonization of host cells. PMID:22454195

  19. Heterologous expression of a plant arginine decarboxylase gene in Trypanosoma cruzi.

    Science.gov (United States)

    Carrillo, Carolina; Serra, María P; Pereira, Claudio A; Huber, Alejandra; González, Nélida S; Algranati, Israel D

    2004-11-01

    Wild-type Trypanosoma cruzi epimastigotes lack arginine decarboxylase (ADC) enzymatic activity. However, the transformation of these parasites with a recombinant plasmid containing the oat ADC cDNA coding region gave rise to the transient heterologous expression of the enzyme, suggesting the absence of endogenous mechanisms that could inhibit the expression of a hypothetical own ADC gene or the assay used to measure its enzymatic activity. The foreign ADC enzyme expressed in the transgenic T. cruzi was characterized by identification of the products, the stoichiometry of the catalysed reaction, the specific inhibition by alpha-difluoromethylarginine (DFMA) and the study of its metabolic turnover. The half-life of the heterologous ADC activity in T. cruzi was about 150 min. Bioinformatics studies and polymerase chain reaction (PCR) analyses seem to indicate the absence of ADC-like DNA sequences in the wild-type T. cruzi genome.

  20. The Uptake of GABA in Trypanosoma cruzi.

    Science.gov (United States)

    Galvez Rojas, Robert L; Ahn, Il-Young; Suárez Mantilla, Brian; Sant'Anna, Celso; Pral, Elizabeth Mieko Furusho; Silber, Ariel Mariano

    2015-01-01

    Gamma aminobutyric acid (GABA) is widely known as a neurotransmitter and signal transduction molecule found in vertebrates, plants, and some protozoan organisms. However, the presence of GABA and its role in trypanosomatids is unknown. Here, we report the presence of intracellular GABA and the biochemical characterization of its uptake in Trypanosoma cruzi, the etiological agent of Chagas' disease. Kinetic parameters indicated that GABA is taken up by a single transport system in pathogenic and nonpathogenic forms. Temperature dependence assays showed a profile similar to glutamate transport, but the effect of extracellular cations Na(+) , K(+) , and H(+) on GABA uptake differed, suggesting a different uptake mechanism. In contrast to reports for other amino acid transporters in T. cruzi, GABA uptake was Na(+) dependent and increased with pH, with a maximum activity at pH 8.5. The sensitivity to oligomycin showed that GABA uptake is dependent on ATP synthesis. These data point to a secondary active Na(+) /GABA symporter energized by Na(+) -exporting ATPase. Finally, we show that GABA occurs in the parasite's cytoplasm under normal culture conditions, indicating that it is regularly taken up from the culture medium or synthesized through an still undescribed metabolic pathway.

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

    Science.gov (United States)

    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

  2. Purification and Partial Characterization of Trypanosoma cruzi Triosephosphate Isomerase

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    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

  3. Nitric oxide-releasing polymeric nanoparticles against Trypanosoma cruzi

    Science.gov (United States)

    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

  4. 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

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    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

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

    Science.gov (United States)

    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

  6. Functional characterization of enzymes involved in cysteine biosynthesis and H(2)S production in Trypanosoma cruzi.

    Science.gov (United States)

    Marciano, Daniela; Santana, Marianela; Nowicki, Cristina

    2012-10-01

    Trypanosoma cruzi is expected to synthetize de novo cysteine by different routes, among which the two-step pathway involving serine acetyltransferase and cysteine synthase (CS) is comprised. Also, cystathionine β synthase (CBS) might contribute to the de novo generation of cysteine in addition to catalyze the first step of the reverse transsulfuration route producing cystathionine. However, neither the functionality of CS nor that of cystathionine γ lyase (CGL) has been assessed. Our results show that T. cruzi CS could participate notably more actively than CBS in the de novo synthesis of cysteine. Interestingly, at the protein level T. cruzi CS is more abundant in amastigotes than in epimastigotes. Unlike the mammalian homologues, T. cruzi CGL specifically cleaves cystathionine into cysteine and is unable to produce H(2)S. The expression pattern of T. cruzi CGL parallels that of CBS, which unexpectedly suggests that in addition to the de novo synthesis of cysteine, the reverse transsulfuration pathway could be operative in the mammalian and insect stages. Besides, T. cruzi CBS produces H(2)S by decomposing cysteine or via condensation of cysteine with homocysteine. The latter reaction leads to cystathionine production, and is catalyzed remarkably more efficiently than the breakdown of cysteine. In T. cruzi like in other organisms, H(2)S could exert regulatory effects on varied metabolic processes. Notably, T. cruzi seems to count on stage-specific routes involved in cysteine production, the multiple cysteine-processing alternatives could presumably reflect this parasite's high needs of reducing power for detoxification of reactive oxygen species.

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

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    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.

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

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    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.

  9. Treatment Success in Trypanosoma cruzi Infection Is Predicted by Early Changes in Serially Monitored Parasite-Specific T and B Cell Responses.

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    María G Alvarez

    2016-04-01

    Full Text Available Chagas disease is the highest impact parasitic disease in Latin America. We have proposed that changes in Trypanosoma cruzi-specific immune responses might serve as surrogate indicators of treatment success. Herein, we addressed in a long-term follow-up study whether cure achieved after treatment can be predicted by changes in non-conventional indexes of anti-parasite serological and T cell activities.T. cruzi-specific T cell responses, as measured by interferon-γ ELISPOT and T. cruzi-specific antibodies assessed by ELISA, hemagglutination and immunofluorescence tests as well as by a multiplex assay incorporating 14 recombinant T. cruzi proteins were measured in 33 patients at 48-150 months post-benznidazole treatment. Cure - as assessed by conventional serological tests - was associated with an early decline in T. cruzi-specific IFN-γ-producing T cells and in antibody titers measured by the multiplex serological assay. Changes in the functional status and potential of T. cruzi-specific T cells, indicative of reduced antigen stimulation, provided further evidence of parasitological cure following benznidazole treatment. Patients showing a significant reduction in T. cruzi-specific antibodies had higher pre-therapy levels of T. cruzi-specific IFN-γ- producing T cells compared to those with unaltered humoral responses post-treatment.Monitoring of appropriate immunological responses can provide earlier and robust measures of treatment success in T. cruzi infection.

  10. Treatment Success in Trypanosoma cruzi Infection Is Predicted by Early Changes in Serially Monitored Parasite-Specific T and B Cell Responses

    Science.gov (United States)

    Cooley, Gretchen; Albareda, María C.; Viotti, Rodolfo; Perez-Mazliah, Damián E.; Lococo, Bruno; Castro Eiro, Melisa; Laucella, Susana A.; Tarleton, Rick L.

    2016-01-01

    Background Chagas disease is the highest impact parasitic disease in Latin America. We have proposed that changes in Trypanosoma cruzi-specific immune responses might serve as surrogate indicators of treatment success. Herein, we addressed in a long-term follow-up study whether cure achieved after treatment can be predicted by changes in non-conventional indexes of anti-parasite serological and T cell activities. Methodology/Principal Findings T. cruzi-specific T cell responses, as measured by interferon-γ ELISPOT and T. cruzi-specific antibodies assessed by ELISA, hemagglutination and immunofluorescence tests as well as by a multiplex assay incorporating 14 recombinant T. cruzi proteins were measured in 33 patients at 48–150 months post-benznidazole treatment. Cure — as assessed by conventional serological tests — was associated with an early decline in T. cruzi-specific IFN-γ-producing T cells and in antibody titers measured by the multiplex serological assay. Changes in the functional status and potential of T. cruzi-specific T cells, indicative of reduced antigen stimulation, provided further evidence of parasitological cure following benznidazole treatment. Patients showing a significant reduction in T. cruzi-specific antibodies had higher pre-therapy levels of T. cruzi-specific IFN-γ- producing T cells compared to those with unaltered humoral responses post-treatment. Conclusions/Significance Monitoring of appropriate immunological responses can provide earlier and robust measures of treatment success in T. cruzi infection. PMID:27128444

  11. Recent, independent and anthropogenic origins of Trypanosoma cruzi hybrids.

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    Michael D Lewis

    2011-10-01

    Full Text Available The single celled eukaryote Trypanosoma cruzi, a parasite transmitted by numerous species of triatomine bug in the Americas, causes Chagas disease in humans. T. cruzi generally reproduces asexually and appears to have a clonal population structure. However, two of the six major circulating genetic lineages, TcV and TcVI, are TcII-TcIII inter-lineage hybrids that are frequently isolated from humans in regions where chronic Chagas disease is particularly severe. Nevertheless, a prevalent view is that hybridisation events in T. cruzi were evolutionarily ancient and that active recombination is of little epidemiological importance. We analysed genotypes of hybrid and non-hybrid T. cruzi strains for markers representing three distinct evolutionary rates: nuclear GPI sequences (n = 88, mitochondrial COII-ND1 sequences (n = 107 and 28 polymorphic microsatellite loci (n = 35. Using Maximum Likelihood and Bayesian phylogenetic approaches we dated key evolutionary events in the T. cruzi clade including the emergence of hybrid lineages TcV and TcVI, which we estimated to have occurred within the last 60,000 years. We also found evidence for recent genetic exchange between TcIII and TcIV and between TcI and TcIV. These findings show that evolution of novel recombinants remains a potential epidemiological risk. The clearly distinguishable microsatellite genotypes of TcV and TcVI were highly heterozygous and displayed minimal intra-lineage diversity indicative of even earlier origins than sequence-based estimates. Natural hybrid genotypes resembled typical meiotic F1 progeny, however, evidence for mitochondrial introgression, absence of haploid forms and previous experimental crosses indicate that sexual reproduction in T. cruzi may involve alternatives to canonical meiosis. Overall, the data support two independent hybridisation events between TcII and TcIII and a recent, rapid spread of the hybrid progeny in domestic transmission cycles

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

    OpenAIRE

    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...

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

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    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.

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

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    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.

  15. Avaliação da atividade antiparasitária do alopurinol, referente ao Trypanosoma cruzi, em sistema experimental que utiliza triatomíneos infectados Evaluation of antiparasitic activity of allopurinol, against Trypanosoma cruzi, in experimental system using infected triatomines

    OpenAIRE

    Fábio Luís Carignani; Lúcia Maria Almeida Braz; Vicente Amato Neto; Eliana Rodrigues de Souza

    2000-01-01

    Foi avaliada a atividade antiparasitária do alopurinol, referente ao Trypanosoma cruzi, através de procedimento que depende da utilização de triatomíneos infectados. De acordo com a metodologia usada, o fármaco não eliminou o protozoário do tubo digestivo dos insetos. Não ocorreu, portanto, obtenção de novo subsídio para melhor entendimento da posição do alopurinol no contexto do tratamento etiológico da infecção pelo T. cruzi, porquanto ela continua em foco, se bem que eivada de divergências...

  16. Diverse inhibitor chemotypes targeting Trypanosoma cruzi CYP51.

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    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

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

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    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

  18. Glyceraldehyde 3-phosphate dehydrogenase-telomere association correlates with redox status in Trypanosoma cruzi.

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    Ricardo Pariona-Llanos

    Full Text Available Glyceraldehyde 3-phosphate dehydrogenase (GAPDH is a classical metabolic enzyme involved in energy production and plays a role in additional nuclear functions, including transcriptional control, recognition of misincorporated nucleotides in DNA and maintenance of telomere structure. Here, we show that the recombinant protein T. cruzi GAPDH (rTcGAPDH binds single-stranded telomeric DNA. We demonstrate that the binding of GAPDH to telomeric DNA correlates with the balance between oxidized and reduced forms of nicotinamide adenine dinucleotides (NAD+/NADH. We observed that GAPDH-telomere association and NAD+/NADH balance changed throughout the T. cruzi life cycle. For example, in replicative epimastigote forms of T. cruzi, which show similar intracellular concentrations of NAD+ and NADH, GAPDH binds to telomeric DNA in vivo and this binding activity is inhibited by exogenous NAD+. In contrast, in the T. cruzi non-proliferative trypomastigote forms, which show higher NAD+ concentration, GAPDH was absent from telomeres. In addition, NAD+ abolishes physical interaction between recombinant GAPDH and synthetic telomere oligonucleotide in a cell free system, mimicking exogenous NAD+ that reduces GAPDH-telomere interaction in vivo. We propose that the balance in the NAD+/NADH ratio during T. cruzi life cycle homeostatically regulates GAPDH telomere association, suggesting that in trypanosomes redox status locally modulates GAPDH association with telomeric DNA.

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

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    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

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

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    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

  1. Real time monitoring of drug action on T. cruzi parasites using a biospeckle laser method

    Science.gov (United States)

    Ansari, M. Z.; Grassi, H. C.; Cabrera, H.; Andrades, E. D. J.

    2016-06-01

    In this paper, we report on a biospeckle laser method used to monitor a specific drug action on T. cruzi parasites. Experimental results from fast biospeckle monitoring of the parasites’ activity under the influence of the drug demonstrate the effectiveness of the proposed method. We measure the speckle parameters such as spatiotemporal correlation and speckle grain size to assess the immediate action of the drug on the parasites during a very short incubation period. From a practical point of view, this aproach allows us to validate biospeckle as a fast, non-invasive and alternative method to test candidate drugs on T. cruzi parasites.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Unveiling the Trypanosoma cruzi Nuclear Proteome.

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    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.

  4. Unveiling the Trypanosoma cruzi Nuclear Proteome.

    Science.gov (United States)

    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

  5. Structures of dihydrofolate reductase-thymidylate synthase of Trypanosoma cruzi in the folate-free state and in complex with two antifolate drugs, trimetrexate and methotrexate

    Energy Technology Data Exchange (ETDEWEB)

    Senkovich, Olga; Schormann, Norbert; Chattopadhyay, Debasish; (UAB)

    2010-11-22

    The flagellate protozoan parasite Trypanosoma cruzi is the pathogenic agent of Chagas disease (also called American trypanosomiasis), which causes approximately 50 000 deaths annually. The disease is endemic in South and Central America. The parasite is usually transmitted by a blood-feeding insect vector, but can also be transmitted via blood transfusion. In the chronic form, Chagas disease causes severe damage to the heart and other organs. There is no satisfactory treatment for chronic Chagas disease and no vaccine is available. There is an urgent need for the development of chemotherapeutic agents for the treatment of T. cruzi infection and therefore for the identification of potential drug targets. The dihydrofolate reductase activity of T. cruzi, which is expressed as part of a bifunctional enzyme, dihydrofolate reductase-thymidylate synthase (DHFR-TS), is a potential target for drug development. In order to gain a detailed understanding of the structure-function relationship of T. cruzi DHFR, the three-dimensional structure of this protein in complex with various ligands is being studied. Here, the crystal structures of T. cruzi DHFR-TS with three different compositions of the DHFR domain are reported: the folate-free state, the complex with the lipophilic antifolate trimetrexate (TMQ) and the complex with the classical antifolate methotrexate (MTX). These structures reveal that the enzyme is a homodimer with substantial interactions between the two TS domains of neighboring subunits. In contrast to the enzymes from Cryptosporidium hominis and Plasmodium falciparum, the DHFR and TS active sites of T. cruzi lie on the same side of the monomer. As in other parasitic DHFR-TS proteins, the N-terminal extension of the T. cruzi enzyme is involved in extensive interactions between the two domains. The DHFR active site of the T. cruzi enzyme shows subtle differences compared with its human counterpart. These differences may be exploited for the development of

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

    Science.gov (United States)

    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

  7. Genetic immunization based on the ubiquitin-fusion degradation pathway against Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Bin [Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180 (Japan); Department of Parasitology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan); Hiromatsu, Kenji, E-mail: khiromatsu@fukuoka-u.ac.jp [Department of Microbiology and Immunology, Faculty of Medicine, Fukuoka University, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180 (Japan); Hisaeda, Hajime; Duan, Xuefeng; Imai, Takashi [Department of Parasitology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan); Murata, Shigeo; Tanaka, Keiji [Department of Molecular Oncology, The Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613 (Japan); Himeno, Kunisuke [Department of Parasitology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582 (Japan)

    2010-02-12

    Cytotoxic CD8{sup +} T cells are particularly important to the development of protective immunity against the intracellular protozoan parasite, Trypanosoma cruzi, the etiological agent of Chagas disease. We have developed a new effective strategy of genetic immunization by activating CD8{sup +} T cells through the ubiquitin-fusion degradation (UFD) pathway. We constructed expression plasmids encoding the amastigote surface protein-2 (ASP-2) of T. cruzi. To induce the UFD pathway, a chimeric gene encoding ubiquitin fused to ASP-2 (pUB-ASP-2) was constructed. Mice immunized with pUB-ASP-2 presented lower parasitemia and longer survival period, compared with mice immunized with pASP-2 alone. Depletion of CD8{sup +} T cells abolished protection against T. cruzi in mice immunized with pUB-ASP-2 while depletion of CD4{sup +} T cells did not influence the effective immunity. Mice deficient in LMP2 or LMP7, subunits of immunoproteasomes, were not able to develop protective immunity induced. These results suggest that ubiquitin-fused antigens expressed in antigen-presenting cells were effectively degraded via the UFD pathway, and subsequently activated CD8{sup +} T cells. Consequently, immunization with pUB-ASP-2 was able to induce potent protective immunity against infection of T. cruzi.

  8. Genetic immunization based on the ubiquitin-fusion degradation pathway against Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Cytotoxic CD8+ T cells are particularly important to the development of protective immunity against the intracellular protozoan parasite, Trypanosoma cruzi, the etiological agent of Chagas disease. We have developed a new effective strategy of genetic immunization by activating CD8+ T cells through the ubiquitin-fusion degradation (UFD) pathway. We constructed expression plasmids encoding the amastigote surface protein-2 (ASP-2) of T. cruzi. To induce the UFD pathway, a chimeric gene encoding ubiquitin fused to ASP-2 (pUB-ASP-2) was constructed. Mice immunized with pUB-ASP-2 presented lower parasitemia and longer survival period, compared with mice immunized with pASP-2 alone. Depletion of CD8+ T cells abolished protection against T. cruzi in mice immunized with pUB-ASP-2 while depletion of CD4+ T cells did not influence the effective immunity. Mice deficient in LMP2 or LMP7, subunits of immunoproteasomes, were not able to develop protective immunity induced. These results suggest that ubiquitin-fused antigens expressed in antigen-presenting cells were effectively degraded via the UFD pathway, and subsequently activated CD8+ T cells. Consequently, immunization with pUB-ASP-2 was able to induce potent protective immunity against infection of T. cruzi.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. The cell surface of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Rosiane V da Silva

    Full Text Available 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.

  13. Predominance of Trypanosoma cruzi I among Panamanian sylvatic isolates.

    Science.gov (United States)

    Samudio, Franklyn; Ortega-Barría, Eduardo; Saldaña, Azael; Calzada, Jose

    2007-02-01

    Trypanosoma cruzi is throughout Panama, which is in agreement with the widespread of the sylvatic vectors implicated in the transmission. Eco-epidemiological changes in some regions of the country have led to a successful dissemination of the palm-tree Attalea butyracea and a possible adaptation of the primary vector of Chagas' disease to human settlements. These facts might increase both vector-human contact and human infection with different potentials T. cruzi genotypes and make therefore necessary a study to disclose Panamanian T. cruzi make-up. In this study, 71 T. cruzi isolates from Rhodnius pallescens were analyzed using mini-exon gene and sequence-characterized amplified region markers. The analyzed strains were T. cruzi lineage I. This finding along with prior results indicates that T. cruzi I is the principal genotype circulating in both sylvatic and domestic/peridomestic cycles and consequently responsible for the disease in the country.

  14. The effect of placental subfractions on Trypanosoma cruzi.

    Science.gov (United States)

    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

  15. Structural Basis for Rational Design of Inhibitors Targeting Trypanosoma cruzi Sterol 14α-Demethylase: Two Regions of the Enzyme Molecule Potentiate Its Inhibition

    OpenAIRE

    Friggeri, Laura; Hargrove, Tatiana Y.; Rachakonda, Girish; Williams, Amanda D; Wawrzak, Zdzislaw; Di Santo, Roberto; De Vita, Daniela; Waterman, Michael R.; Tortorella, Silvano; Villalta, Fernando; Lepesheva, Galina I.

    2014-01-01

    Chagas disease, which was once thought to be confined to endemic regions of Latin America, has now gone global, becoming a new worldwide challenge with no cure available. The disease is caused by the protozoan parasite Trypanosoma cruzi, which depends on the production of endogenous sterols, and therefore can be blocked by sterol 14α-demethylase (CYP51) inhibitors. Here we explore the spectral binding parameters, inhibitory effects on T. cruzi CYP51 activity, and antiparasitic potencies of a ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. Validation of N-myristoyltransferase as Potential Chemotherapeutic Target in Mammal-Dwelling Stages of Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Linda J Herrera

    2016-04-01

    Full Text Available Trypanosoma cruzi causes Chagas disease, an endemic and debilitating illness in Latin America. Lately, owing to extensive population movements, this neglected tropical disease has become a global health concern. The two clinically available drugs for the chemotherapy of Chagas disease have rather high toxicity and limited efficacy in the chronic phase of the disease, and may induce parasite resistance. The development of new anti-T. cruzi agents is therefore imperative. The enzyme N-myristoyltransferase (NMT has recently been biochemically characterized, shown to be essential in Leishmania major, Trypanosoma brucei, and T. cruzi¸ and proposed as promising chemotherapeutic target in these trypanosomatids.Here, using high-content imaging we assayed eight known trypanosomatid NMT inhibitors, against mammal-dwelling intracellular amastigote and trypomastigote stages and demonstrated that three of them (compounds 1, 5, and 8 have potent anti-proliferative effect at submicromolar concentrations against T. cruzi, with very low toxicity against human epithelial cells. Moreover, metabolic labeling using myristic acid, azide showed a considerable decrease in the myristoylation of proteins in parasites treated with NMT inhibitors, providing evidence of the on-target activity of the inhibitors.Taken together, our data point out to the potential use of NMT inhibitors as anti-T. cruzi chemotherapy.

  18. Trypanosoma cruzi, cancer and the Cold War.

    Science.gov (United States)

    Krementsov, Nikolai

    2009-07-01

    In the summer of 1946, the international community of cancer researchers was inspired by the announcement that two Soviet scientists, Nina Kliueva and Grigorii Roskin, had discovered anticancer properties in culture extracts made from the South American protozoan, Trypanosoma cruzi, and had produced a preparation--named after its discoverers KR--which showed clear therapeutic effects on cancer patients. Research teams from various countries enthusiastically pursued the promising new line of investigation. The story of the rise and fall of interest in the anticancer properties of T. cruzi in different countries suggests that during the second half of the twentieth century, the Cold War competition between the superpowers played an important role in shaping the research agendas of cancer studies.

  19. Sequence variation in CYP51A from the Y strain of Trypanosoma cruzi alters its sensitivity to inhibition

    OpenAIRE

    Cherkesova, Tatiana S.; Hargrove, Tatiana Y.; Vanrell, M. Cristina; Ges, Igor; Usanov, Sergey A.; Romano, Patricia S.; Lepesheva, Galina I.

    2014-01-01

    CYP51 (sterol 14α-demethylase) is an efficient target for clinical and agricultural antifungals and an emerging target for treatment of Chagas disease, the infection that is caused by multiple strains of a protozoan pathogen Trypanosoma cruzi. Here, we analyze CYP51A from the Y strain T. cruzi. In this protein, proline 355, a residue highly conserved across the CYP51 family, is replaced with serine. The purified enzyme retains its catalytic activity, yet has been found less susceptible to inh...

  20. Rational development of 4-aminopyridyl-based inhibitors targeting Trypanosoma cruzi CYP51 as anti-Chagas agents

    OpenAIRE

    Choi, Jun Yong; Calvet, Claudia M.; Gunatilleke, Shamila S.; Ruiz, Claudia; Cameron, Michael D.; McKerrow, James H.; Larissa M. Podust; Roush, William R.

    2013-01-01

    A new series of 4-aminopyridyl-based lead inhibitors targeting Trypanosoma cruzi CYP51 (TcCYP51) has been developed using structure-based drug design as well as structure-property relationship (SPR) analyses. The screening hit starting point, LP10 (KD ≤ 42 nM; EC50 of 0.65 µM), has been optimized to give the potential leads 14t, 27i, 27q, 27r, and 27t, that have low nanomolar binding affinity to TcCYP51 and significant activity against T. cruzi amastigotes cultured in human myoblasts (EC50 = ...

  1. Genotypic variation among lineages of Trypanosoma cruzi and its geographic aspects.

    Science.gov (United States)

    Higo, Hiroo; Miura, Sachio; Horio, Masahiro; Mimori, Tatsuyuki; Hamano, Shinjiro; Agatsuma, Takeshi; Yanagi, Tetsuo; Cruz-Reyes, Arejandro; Uyema, Norma; Rojas de Arias, A; Matta, Vivian; Akahane, Hiroshige; Hirayama, Kenji; Takeuchi, Tsutomu; Tada, Isao; Himeno, Kunisuke

    2004-12-01

    Isozyme analysis with 18 enzyme loci was conducted on 146 isolates of Trypanosoma cruzi from Mexico, Guatemala, Colombia, Ecuador, Peru, Brazil, Bolivia, Paraguay and Chile. Forty-four different MLGs (groups of isolates with identical multilocus genotypes) were identified and a phylogeny was constructed. The phylogenetic tree consisted of two main groups (T. cruzi I, T. cruzi II), and the latter was further divided into two subgroups (T. cruzi IIa, T. cruzi IIb-e). Evidence of hybridization between different MLGs of T. cruzi II was found, which means that genetic exchanges seem to have occurred in South American T. cruzi. On the other hand, the persistence of characteristic T. cruzi I and T. cruzi II isozyme patterns in single small villages in Bolivia and Guatemala suggested that genetic exchange is very rare between major lineages. A significant difference in genetic diversity was shown between T. cruzi I and T. cruzi II from several indices of population genetics. Two possibilities could explain this genetic variation in the population: differences in evolutionary history and/or different tendencies to exchange genetic material. Broad-scale geographic distributions of T. cruzi I and T. cruzi IIb-e were different; T. cruzi I occurred in Central America and south to Bolivia and Brazil, while T. cruzi IIb-e occurred in the central and southern areas of South America, overlapping with T. cruzi I in Brazil and Bolivia.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. Biotherapic T. cruzi 17DH when continuously used clinically improves mice infected with T. cruzi.

    Directory of Open Access Journals (Sweden)

    Silvana Marques de Araujo

    2011-09-01

    Full Text Available Introduction: In Trypanosoma cruzi infection, the pathogenesis is the result of a rupture in the host - parasite relationship [1]. This rupture is related to the imbalance of the vital force of the host, expressed through signs and symptoms, defined by Hahnemann (1995[2] as being the source of the disease. There is no research in the literature about the clinical evolution of mice experimentally infected with T. cruzi and treated in different ways using biotherapic. Therefore, this is an area to be studied in the future. Aim: To evaluate the effect of different ways of treatment using biotherapic T. cruzi 17 DH on clinical evolution of mice experimentally infected with T. cruzi. Materials and methods: A blind randomized controlled trial was performed, using 30 swiss male mice, aged 28 days, divided into groups according to the treatment: CONTROL - animals treated with 7% water-alcohol solution diluted in water given ad libitum in an amber bottle; GAVAGE – animals treated with medication highly diluted T. cruzi 17 DH from 4th to 9th day of infection by gavage; WATER -animals treated with highly diluted T. cruzi 17 DH in water ad libitum offered in an amber bottle until the end of the study period. The groups were infected with the Y strain of T. cruzi, intraperitoneal, 1400 blood trypomastigotes. The medicine was handled according to the Brazilian Homeopathic Pharmacopoeia [3] with microbiological test according to RDC n° 67 and in vivo biological risk. Parasitemic curve was determined by daily counting of the parasites [4]. Were measured temperature, weight, intake of water and feed, the ruffle fur and survival of mice. Statistical analysis was performed using the tests Fisher Exact and Log-Rank, with a significance of 5%. The experiment was approved under the protocol n° 030/2008 - Ethics in Animal Experimentation of the Universidade Estadual de Maringá. Results: The mice under different

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

    OpenAIRE

    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.

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

    Science.gov (United States)

    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

  6. The Effectiveness of Natural Diarylheptanoids against Trypanosoma cruzi: Cytotoxicity, Ultrastructural Alterations and Molecular Modeling Studies

    Science.gov (United States)

    Sueth-Santiago, Vitor; Moraes, Julliane de B. B.; Sobral Alves, Eliomara Sousa; Vannier-Santos, Marcos André; Freire-de-Lima, Célio G.; Castro, Rosane N.; Mendes-Silva, Gustavo Peron; Del Cistia, Catarina de Nigris; Magalhães, Luma Godoy; Andricopulo, Adriano Defini; Sant´Anna, Carlos Mauricio R.; Decoté-Ricardo, Debora; Freire de Lima, Marco Edilson

    2016-01-01

    Curcumin (CUR) is the major constituent of the rhizomes of Curcuma longa and has been widely investigated for its chemotherapeutic properties. The well-known activity of CUR against Leishmania sp., Trypanosoma brucei and Plasmodium falciparum led us to investigate its activity against Trypanosoma cruzi. In this work, we tested the cytotoxic effects of CUR and other natural curcuminoids on different forms of T. cruzi, as well as the ultrastructural changes induced in epimastigote form of the parasite. CUR was verified as the curcuminoid with more significant trypanocidal properties (IC50 10.13 μM on epimastigotes). Demethoxycurcumin (DMC) was equipotent to CUR (IC50 11.07 μM), but bisdemethoxycurcumin (BDMC) was less active (IC50 45.33 μM) and cyclocurcumin (CC) was inactive. In the experiment with infected murine peritoneal macrophages all diarylheptanoids were more active than the control in the inhibition of the trypomastigotes release. The electron microscopy images showed ultrastructural changes associated with the cytoskeleton of the parasite, indicating tubulin as possible target of CUR in T. cruzi. The results obtained by flow cytometry analysis of DNA content of the parasites treated with natural curcuminoids suggested a mechanism of action on microtubules related to the paclitaxel`s mode of action. To better understand the mechanism of action highlighted by electron microscopy and flow cytometry experiments we performed the molecular docking of natural curcuminoids on tubulin of T. cruzi in a homology model and the results obtained showed that the observed interactions are in accordance with the IC50 values found, since there CUR and DMC perform similar interactions at the binding site on tubulin while BDMC do not realize a hydrogen bond with Lys163 residue due to the absence of methoxyl groups. These results indicate that trypanocidal properties of CUR may be related to the cytoskeletal alterations. PMID:27658305

  7. Expression and the Peculiar Enzymatic Behavior of the Trypanosoma cruzi NTH1 DNA Glycosylase

    Science.gov (United States)

    Ormeño, Fernando; Barrientos, Camila; Ramirez, Santiago; Ponce, Iván; Valenzuela, Lucía; Sepúlveda, Sofía; Bitar, Mainá; Kemmerling, Ulrike; Machado, Carlos Renato; Cabrera, Gonzalo; Galanti, Norbel

    2016-01-01

    Trypanosoma cruzi, the etiological agent of Chagas’ disease, presents three cellular forms (trypomastigotes, epimastigotes and amastigotes), all of which are submitted to oxidative species in its hosts. However, T. cruzi is able to resist oxidative stress suggesting a high efficiency of its DNA repair machinery.The Base Excision Repair (BER) pathway is one of the main DNA repair mechanisms in other eukaryotes and in T. cruzi as well. DNA glycosylases are enzymes involved in the recognition of oxidative DNA damage and in the removal of oxidized bases, constituting the first step of the BER pathway. Here, we describe the presence and activity of TcNTH1, a nuclear T. cruzi DNA glycosylase. Surprisingly, purified recombinant TcNTH1 does not remove the thymine glycol base, but catalyzes the cleavage of a probe showing an AP site. The same activity was found in epimastigote and trypomastigote homogenates suggesting that the BER pathway is not involved in thymine glycol DNA repair. TcNTH1 DNA-binding properties assayed in silico are in agreement with the absence of a thymine glycol removing function of that parasite enzyme. Over expression of TcNTH1 decrease parasite viability when transfected epimastigotes are submitted to a sustained production of H2O2.Therefore, TcNTH1 is the only known NTH1 orthologous unable to eliminate thymine glycol derivatives but that recognizes and cuts an AP site, most probably by a beta-elimination mechanism. We cannot discard that TcNTH1 presents DNA glycosylase activity on other DNA base lesions. Accordingly, a different DNA repair mechanism should be expected leading to eliminate thymine glycol from oxidized parasite DNA. Furthermore, TcNTH1 may play a role in the AP site recognition and processing. PMID:27284968

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

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    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

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

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    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

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

    Science.gov (United States)

    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

  11. Antiprotozoal activity of Neurolaena lobata.

    Science.gov (United States)

    Berger, I; Passreiter, C M; Cáceres, A; Kubelka, W

    2001-06-01

    Extracts, fractions and sesquiterpene lactones from Neurolaena lobata (L.) R. Br. (Asteraceae), a traditional medicinal plant from Guatemala, were tested in vitro against Leishmania spp. promastigotes, Trypanosoma cruzi trypomastigotes and epimastigotes and Trichomonas vaginalis trophozoites. The ethanol extract inhibited the parasite growth of L. mexicana, T. cruzi and T. vaginalis significantly. The pure germacranolides 1 and a mixture of 2 and 3, isolated from the ethonal extract, were highly active against L. mexicana and T. cruzi. PMID:11406857

  12. Benznidazole biotransformation and multiple targets in Trypanosoma cruzi revealed by metabolomics.

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    Andrea Trochine

    2014-05-01

    Full Text Available The first line treatment for Chagas disease, a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi, involves administration of benznidazole (Bzn. Bzn is a 2-nitroimidazole pro-drug which requires nitroreduction to become active, although its mode of action is not fully understood. In the present work we used a non-targeted MS-based metabolomics approach to study the metabolic response of T. cruzi to Bzn.Parasites treated with Bzn were minimally altered compared to untreated trypanosomes, although the redox active thiols trypanothione, homotrypanothione and cysteine were significantly diminished in abundance post-treatment. In addition, multiple Bzn-derived metabolites were detected after treatment. These metabolites included reduction products, fragments and covalent adducts of reduced Bzn linked to each of the major low molecular weight thiols: trypanothione, glutathione, γ-glutamylcysteine, glutathionylspermidine, cysteine and ovothiol A. Bzn products known to be generated in vitro by the unusual trypanosomal nitroreductase, TcNTRI, were found within the parasites, but low molecular weight adducts of glyoxal, a proposed toxic end-product of NTRI Bzn metabolism, were not detected.Our data is indicative of a major role of the thiol binding capacity of Bzn reduction products in the mechanism of Bzn toxicity against T. cruzi.

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

    Science.gov (United States)

    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

  14. Critical importance of the de novo pyrimidine biosynthesis pathway for Trypanosoma cruzi growth in the mammalian host cell cytoplasm

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Muneaki, E-mail: muneaki@juntendo.ac.jp [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Morales, Jorge; Fukai, Yoshihisa; Suzuki, Shigeo; Takamiya, Shinzaburo; Tsubouchi, Akiko; Inoue, Syou [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Inoue, Masayuki [Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kita, Kiyoshi [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Harada, Shigeharu [Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Tanaka, Akiko [Systems and Structural Biology Center, RIKEN, Tsurumi, Yokohama 230-0045 (Japan); Aoki, Takashi [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Nara, Takeshi, E-mail: tnara@juntendo.ac.jp [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2012-01-20

    Highlights: Black-Right-Pointing-Pointer We established Trypanosoma cruzi lacking the gene for carbamoyl phosphate synthetase II. Black-Right-Pointing-Pointer Disruption of the cpsII gene significantly reduced the growth of epimastigotes. Black-Right-Pointing-Pointer In particular, the CPSII-null mutant severely retarded intracellular growth. Black-Right-Pointing-Pointer The de novo pyrimidine pathway is critical for the parasite growth in the host cell. -- Abstract: The intracellular parasitic protist Trypanosoma cruzi is the causative agent of Chagas disease in Latin America. In general, pyrimidine nucleotides are supplied by both de novo biosynthesis and salvage pathways. While epimastigotes-an insect form-possess both activities, amastigotes-an intracellular replicating form of T. cruzi-are unable to mediate the uptake of pyrimidine. However, the requirement of de novo pyrimidine biosynthesis for parasite growth and survival has not yet been elucidated. Carbamoyl-phosphate synthetase II (CPSII) is the first and rate-limiting enzyme of the de novo biosynthetic pathway, and increased CPSII activity is associated with the rapid proliferation of tumor cells. In the present study, we showed that disruption of the T. cruzicpsII gene significantly reduced parasite growth. In particular, the growth of amastigotes lacking the cpsII gene was severely suppressed. Thus, the de novo pyrimidine pathway is important for proliferation of T. cruzi in the host cell cytoplasm and represents a promising target for chemotherapy against Chagas disease.

  15. Immune Evasion Strategies of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    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.

  16. Flagellar Motility of Trypanosoma cruzi Epimastigotes

    Directory of Open Access Journals (Sweden)

    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.

  17. Differential gene expression during Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    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.

  18. Trypanosoma cruzi disrupts thymic homeostasis by altering intrathymic and systemic stress-related endocrine circuitries.

    Directory of Open Access Journals (Sweden)

    Ailin Lepletier

    2013-11-01

    Full Text Available We have previously shown that experimental infection caused by Trypanosoma cruzi is associated with changes in the hypothalamus-pituitary-adrenal axis. Increased glucocorticoid (GC levels are believed to be protective against the effects of acute stress during infection but result in depletion of CD4(+CD8(+ thymocytes by apoptosis, driving to thymic atrophy. However, very few data are available concerning prolactin (PRL, another stress-related hormone, which seems to be decreased during T. cruzi infection. Considering the immunomodulatory role of PRL upon the effects caused by GC, we investigated if intrathymic cross-talk between GC and PRL receptors (GR and PRLR, respectively might influence T. cruzi-induced thymic atrophy. Using an acute experimental model, we observed changes in GR/PRLR cross-activation related with the survival of CD4(+CD8(+ thymocytes during infection. These alterations were closely related with systemic changes, characterized by a stress hormone imbalance, with progressive GC augmentation simultaneously to PRL reduction. The intrathymic hormone circuitry exhibited an inverse modulation that seemed to counteract the GC-related systemic deleterious effects. During infection, adrenalectomy protected the thymus from the increase in apoptosis ratio without changing PRL levels, whereas an additional inhibition of circulating PRL accelerated the thymic atrophy and led to an increase in corticosterone systemic levels. These results demonstrate that the PRL impairment during infection is not caused by the increase of corticosterone levels, but the opposite seems to occur. Accordingly, metoclopramide (MET-induced enhancement of PRL secretion protected thymic atrophy in acutely infected animals as well as the abnormal export of immature and potentially autoreactive CD4(+CD8(+ thymocytes to the periphery. In conclusion, our findings clearly show that Trypanosoma cruzi subverts mouse thymus homeostasis by altering intrathymic and

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  20. Molecular modeling studies and in vitro bioactivity evaluation of a set of novel 5-nitro-heterocyclic derivatives as anti-T. cruzi agents.

    Science.gov (United States)

    Paula, Fávero Reisdorfer; Jorge, Salomão Dória; de Almeida, Leonardo Viana; Pasqualoto, Kerly Fernanda Mesquita; Tavares, Leoberto Costa

    2009-04-01

    In this study, in vitro anti-T. cruzi activity assays of nifuroxazide (NX) analogues, such as 5-nitro-2-furfuryliden and 5-nitro-2-theniliden derivatives, were performed. A molecular modeling approach was also carried out to relate the lipophilicity potential (LP) property and biological activity data. The majority of the NX derivatives showed increased anti-T. cruzi activity in comparison to the reference drug, benznidazole (BZN). Additionally, the 5-nitro-2-furfuryliden derivatives presented better pharmacological profile than the 5-nitro-2-theniliden analogues. The LP maps and corresponding ClogP values indicate that there is an optimum lipophilicity value, which must be observed in the design of new potential anti-T. cruzi agents. PMID:19303308

  1. TcruziDB, an Integrated Database, and the WWW Information Server for the Trypanosoma cruzi Genome Project

    Directory of Open Access Journals (Sweden)

    Degrave Wim

    1997-01-01

    Full Text Available Data analysis, presentation and distribution is of utmost importance to a genome project. A public domain software, ACeDB, has been chosen as the common basis for parasite genome databases, and a first release of TcruziDB, the Trypanosoma cruzi genome database, is available by ftp from ftp://iris.dbbm.fiocruz.br/pub/genomedb/TcruziDB as well as versions of the software for different operating systems (ftp://iris.dbbm.fiocruz.br/pub/unixsoft/. Moreover, data originated from the project are available from the WWW server at http://www.dbbm.fiocruz.br. It contains biological and parasitological data on CL Brener, its karyotype, all available T. cruzi sequences from Genbank, data on the EST-sequencing project and on available libraries, a T. cruzi codon table and a listing of activities and participating groups in the genome project, as well as meeting reports. T. cruzi discussion lists (tcruzi-l@iris.dbbm.fiocruz.br and tcgenics@iris.dbbm.fiocruz.br are being maintained for communication and to promote collaboration in the genome project

  2. Amastigotes forms of Trypanosoma cruzi detected in a renal allograft

    Directory of Open Access Journals (Sweden)

    CARVALHO Maria Fernanda C.

    1997-01-01

    Full Text Available Trypanosoma cruzi, the causative agent of Chagas?disease assumes two distinct forms in vertebrate hosts: circulating trypomastigote and tissular amastigote. This latter form infects predominantly the myocardium, smooth and skeletal muscle, and central nervous system. The present work describes for the first time the detection of amastigote forms of T. cruzi in the renal parenchyma of a kidney graft recipient one month after transplantation. The patient was serologically negative for Chagas?disease and received no blood transfusion prior to transplant. The cadaver donor was from an endemic area for Chagas?disease. The recipient developed the acute form of the disease with detection of amastigote forms of T. cruzi in the renal allograft biopsy and circulating trypomastigote forms. The present report demonstrates that T. cruzi can infect the renal parenchyma. This mode of transmission warrants in endemic areas of Chagas?disease

  3. Bed bugs (Cimex lectularius) as vectors of Trypanosoma cruzi.

    Science.gov (United States)

    Salazar, Renzo; Castillo-Neyra, Ricardo; Tustin, Aaron W; Borrini-Mayorí, Katty; Náquira, César; Levy, Michael Z

    2015-02-01

    Populations of the common bed bug, Cimex lectularius, have recently undergone explosive growth. Bed bugs share many important traits with triatomine insects, but it remains unclear whether these similarities include the ability to transmit Trypanosoma cruzi, the etiologic agent of Chagas disease. Here, we show efficient and bidirectional transmission of T. cruzi between hosts and bed bugs in a laboratory environment. Most bed bugs that fed on experimentally infected mice acquired the parasite. A majority of previously uninfected mice became infected after a period of cohabitation with exposed bed bugs. T. cruzi was also transmitted to mice after the feces of infected bed bugs were applied directly to broken host skin. Quantitative bed bug defecation measures were similar to those of important triatomine vectors. Our findings suggest that the common bed bug may be a competent vector of T. cruzi and could pose a risk for vector-borne transmission of Chagas disease. PMID:25404068

  4. Sialic Acid Glycobiology Unveils Trypanosoma cruzi Trypomastigote Membrane Physiology

    OpenAIRE

    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...

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

    OpenAIRE

    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. Trypanosoma cruzi (Chagas' disease agent reduces HIV-1 replication in human placenta

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    Cappa Stella

    2008-07-01

    Full Text Available Abstract Background Several factors determine the risk of HIV mother-to-child transmission (MTCT, such as coinfections in placentas from HIV-1 positive mothers with other pathogens. Chagas' disease is one of the most endemic zoonoses in Latin America, caused by the protozoan Trypanosoma cruzi. The purpose of the study was to determine whether T. cruzi modifies HIV infection of the placenta at the tissue or cellular level. Results Simple and double infections were carried out on a placental histoculture system (chorionic villi isolated from term placentas from HIV and Chagas negative mothers and on the choriocarcinoma BeWo cell line. Trypomastigotes of T. cruzi (VD lethal strain, either purified from mouse blood or from Vero cell cultures, 24 h-supernatants of blood and cellular trypomastigotes, and the VSV-G pseudotyped HIV-1 reporter virus were used for the coinfections. Viral transduction was evaluated by quantification of luciferase activity. Coinfection with whole trypomastigotes, either from mouse blood or from cell cultures, decreased viral pseudotype luciferase activity in placental histocultures. Similar results were obtained from BeWo cells. Supernatants of stimulated histocultures were used for the simultaneous determination of 29 cytokines and chemokines with the Luminex technology. In histocultures infected with trypomastigotes, as well as in coinfected tissues, IL-6, IL-8, IP-10 and MCP-1 production was significantly lower than in controls or HIV-1 transducted tissue. A similar decrease was observed in histocultures treated with 24 h-supernatants of blood trypomastigotes, but not in coinfected tissues. Conclusion Our results demonstrated that the presence of an intracellular pathogen, such as T. cruzi, is able to impair HIV-1 transduction in an in vitro system of human placental histoculture. Direct effects of the parasite on cellular structures as well as on cellular/viral proteins essential for HIV-1 replication might influence

  7. TGF-β receptor type II costameric localization in cardiomyocytes and host cell TGF-β response is disrupted by Trypanosoma cruzi infection.

    Science.gov (United States)

    Calvet, Claudia Magalhães; Silva, Tatiana Araújo; DE Melo, Tatiana Galvão; DE Araújo-Jorge, Tânia Cremonini; Pereira, Mirian Claudia DE Souza

    2016-05-01

    Transforming growth factor beta (TGF-β) cytokine is involved in Chagas disease establishment and progression. Since Trypanosoma cruzi can modulate host cell receptors, we analysed the TGF-β receptor type II (TβRII) expression and distribution during T. cruzi - cardiomyocyte interaction. TβRII immunofluorescent staining revealed a striated organization in cardiomyocytes, which was co-localized with vinculin costameres and enhanced (38%) after TGF-β treatment. Cytochalasin D induced a decrease of 45·3% in the ratio of cardiomyocytes presenting TβRII striations, demonstrating an association of TβRII with the cytoskeleton. Western blot analysis showed that cytochalasin D significantly inhibited Smad 2 phosphorylation and fibronectin stimulation after TGF-β treatment in cardiomyocytes. Trypanosoma cruzi infection elicited a decrease of 79·8% in the frequency of cardiomyocytes presenting TβRII striations, but did not interfere significantly in its expression. In addition, T. cruzi-infected cardiomyocytes present a lower response to exogenous TGF-β, showing no enhancement of TβRII striations and a reduction of phosphorylated Smad 2, with no significant difference in TβRII expression when compared to uninfected cells. Together, these results suggest that the co-localization of TβRII with costameres is important in activating the TGF-β signalling cascade, and that T. cruzi-derived cytoskeleton disorganization could result in altered or low TGF-β response in infected cardiomyocytes.

  8. Sequential combined treatment with allopurinol and benznidazole in the chronic phase of Trypanosoma cruzi infection: a pilot study

    Science.gov (United States)

    Perez-Mazliah, D. E.; Alvarez, M. G.; Cooley, G.; Lococo, B. E.; Bertocchi, G.; Petti, M.; Albareda, M. C.; Armenti, A. H.; Tarleton, R. L.; Laucella, S. A.; Viotti, R.

    2013-01-01

    Objectives Even though the use of combined drugs has been proved to be effective in other chronic infections, assessment of combined treatment of antiparasitic drugs in human Chagas' disease has not been performed. Herein, a pilot study was conducted to evaluate the tolerance and side effects of a sequential combined treatment of two antiparasitic drugs, allopurinol and benznidazole, in the chronic phase of Trypanosoma cruzi infection. Patients and methods Changes in total and T. cruzi-specific T and B cells were monitored during a median follow-up of 36 months. Allopurinol was administered for 3 months (600 mg/day) followed by 30 days of benznidazole (5 mg/kg/day) in 11 T. cruzi-infected subjects. Results The combined sequential treatment of allopurinol and benznidazole was well tolerated. The levels of T. cruzi-specific antibodies significantly decreased after sequential combined treatment, as determined by conventional serology and by a multiplex assay using recombinant proteins. The frequency of T. cruzi-specific interferon-γ-producing T cells significantly increased after allopurinol treatment and decreased to background levels following benznidazole administration in a substantial proportion of subjects evaluated. The levels of total naive (CD45RA + CCR7 + CD62L+) CD4 + and CD8 + T cells were restored after allopurinol administration and maintained after completion of the combined drug protocol, along with a decrease in T cell activation in total peripheral CD4 + and CD8 + T cells. Conclusions This pilot study shows that the combination of allopurinol and benznidazole induces significant modifications in T and B cell responses indicative of a reduction in parasite burden, and sustains the feasibility of administration of two antiparasitic drugs in the chronic phase of Chagas' disease. PMID:23104493

  9. Prevalence of Trypanosoma cruzi's Discrete Typing Units in a cohort of Latin American migrants in Spain.

    Science.gov (United States)

    Martinez-Perez, Angela; Poveda, Cristina; Ramírez, Juan David; Norman, Francesca; Gironés, Núria; Guhl, Felipe; Monge-Maillo, Begoña; Fresno, Manuel; López-Vélez, Rogelio

    2016-05-01

    Chagas disease is caused by the protozoan Trypanosoma cruzi. This is an endemic disease in the Americas, but increased migration to Europe has made it emerge in countries where it was previously unknown, being Spain the second non endemic country in number of patients. T. cruzi is a parasite with a wide genetic diversity, which has been grouped by consensus into 6 Discrete Typing Units (DTUs) affecting humans. Some authors have linked these DTUs either to a specific epidemiological context or to the different clinical presentations. Our main objective was to describe the T. cruzi DTUs identified from a population of chronically infected Latin American migrants attending a reference clinic in Madrid. 149 patients meeting this condition were selected for the study. Molecular characterization was performed by an algorithm that combines PCR of the intergenic region of the mini exon-gene, the 24Sα and 18S regions of rDNA and the variable region of the satellite DNA. A descriptive analysis was performed and associations between geographical/clinical data and the different DTUs were tested. DTUs could be determined in 105 out of 149 patients, 93.3% were from Bolivia, 67.7% were women and median age was 35 years (IQR 29-44). The most common DTU found was TcV (58; 55.2%), followed by TcIV (17; 16.2%), TcII (10; 9.5%) and TcI (4; 3.8%). TcIII and TcVI were not identified from any patient, and 15.2% patients presented mixed infections. In addition, we determined DTUs after treatment in a subset of patients. In 57% patients had different DTUs before and after treatment. DTUs distribution from this study indicates active transmission of T. cruzi is occurring in Bolivia, in both domestic and sylvatic cycles. TcIV was confirmed as a cause of chronic human disease. The current results indicate no correlation between DTU and any specific clinical presentation associated with Chagas disease, nor with geographical origin. Treatment with benznidazole does not always clear T. cruzi

  10. CD8+ T-cells expressing interferon gamma or perforin play antagonistic roles in heart injury in experimental Trypanosoma cruzi-elicited cardiomyopathy.

    Science.gov (United States)

    Silverio, Jaline Coutinho; Pereira, Isabela Resende; Cipitelli, Márcio da Costa; Vinagre, Nathália Ferreira; Rodrigues, Maurício Martins; Gazzinelli, Ricardo Tostes; Lannes-Vieira, Joseli

    2012-01-01

    In Chagas disease, CD8(+) T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8(+) T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC). Here we explored the role of CD8(+) T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8(+) T-cell capacity to produce interferon-gamma (IFNγ) and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8(+) T-cells segregated into IFNγ(+) perforin (Pfn)(neg) or IFNγ(neg)Pfn(+) cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8(+)Pfn(+) cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8(-/-) recipients showed that the CD8(+) cells from infected ifnγ(-/-)pfn(+/+) donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8(+) cells from ifnγ(+/+)pfn(-/-) donors. Moreover, the reconstitution of naïve cd8(-/-) mice with CD8(+) cells from naïve ifnγ(+/+)pfn(-/-) donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ(+) cells accumulation, whereas reconstitution with CD8(+) cells from naïve ifnγ(-/-)pfn(+/+) donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn(+) cells in the cardiac tissue. Our data support a possible antagonist effect of CD8(+)Pfn(+) and CD8(+)IFNγ(+) cells during CCC. CD8(+)IFNγ(+) cells may exert a beneficial role

  11. CD8+ T-cells expressing interferon gamma or perforin play antagonistic roles in heart injury in experimental Trypanosoma cruzi-elicited cardiomyopathy.

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    Jaline Coutinho Silverio

    Full Text Available In Chagas disease, CD8(+ T-cells are critical for the control of Trypanosoma cruzi during acute infection. Conversely, CD8(+ T-cell accumulation in the myocardium during chronic infection may cause tissue injury leading to chronic chagasic cardiomyopathy (CCC. Here we explored the role of CD8(+ T-cells in T. cruzi-elicited heart injury in C57BL/6 mice infected with the Colombian strain. Cardiomyocyte lesion evaluated by creatine kinase-MB isoenzyme activity levels in the serum and electrical abnormalities revealed by electrocardiogram were not associated with the intensity of heart parasitism and myocarditis in the chronic infection. Further, there was no association between heart injury and systemic anti-T. cruzi CD8(+ T-cell capacity to produce interferon-gamma (IFNγ and to perform specific cytotoxicity. Heart injury, however, paralleled accumulation of anti-T. cruzi cells in the cardiac tissue. In T. cruzi infection, most of the CD8(+ T-cells segregated into IFNγ(+ perforin (Pfn(neg or IFNγ(negPfn(+ cell populations. Colonization of the cardiac tissue by anti-T. cruzi CD8(+Pfn(+ cells paralleled the worsening of CCC. The adoptive cell transfer to T. cruzi-infected cd8(-/- recipients showed that the CD8(+ cells from infected ifnγ(-/-pfn(+/+ donors migrate towards the cardiac tissue to a greater extent and caused a more severe cardiomyocyte lesion than CD8(+ cells from ifnγ(+/+pfn(-/- donors. Moreover, the reconstitution of naïve cd8(-/- mice with CD8(+ cells from naïve ifnγ(+/+pfn(-/- donors ameliorated T. cruzi-elicited heart injury paralleled IFNγ(+ cells accumulation, whereas reconstitution with CD8(+ cells from naïve ifnγ(-/-pfn(+/+ donors led to an aggravation of the cardiomyocyte lesion, which was associated with the accumulation of Pfn(+ cells in the cardiac tissue. Our data support a possible antagonist effect of CD8(+Pfn(+ and CD8(+IFNγ(+ cells during CCC. CD8(+IFNγ(+ cells may exert a beneficial role, whereas CD8(+Pfn

  12. Miocardite no macaco Cebus após inoculações repetidas com Schizotrypanum cruzi

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    C. Magarinos Torres

    1958-07-01

    inoculated, four times through the intact ocular conjunctiva (one time with infected blood, and three times with dejections from infected bugs, and five times injected in the skin (four times with contaminated blood, and one time with dejections from infected bugs, and necropsied after 233 days. The microscopic picture was uniform presenting, however, considerable individual variations, and was represented by diffuse interstitial myocarditis, frequently more (marked in the right ventricle base of the heart, accompanied by lymphatic stasis. The infiltration consists of macrophages, plasma cells and lymphocytes, the cellular reaction having sometimes a perivascular distribution, involving the auriculo-ventricular system of conduction, endocardium, epicardium and cardiac sympathetic gangliae. The loss of cardiac muscle fibers was always minimal. Leishmanial forms of S. cruzi in myocardial fibers are scanty and, in two cases, absent. Fatty necrosis in the epicardium was noted in two cases. Obliterative changes of medium-sized branches of coronary arteries (hypersensitivity reaction? and multiple infarcts of the myocardium was found in one instance. The diffuse myocarditis induced by S. cruzi in several species of monkeys of the genus Cebus observed after 233 days (several inoculations and 252 days (single inoculation is not associated with disseminated fibrosis such as is reported in chronic cases of Chagas' disease. Definite capacity of reversion is another characteristic of the interstitial myocarditis observed in the series of Cebus monkeys here studied. The impression was gained that repeated inoculation with S. cruzi may influence the myocardial changes differently according to the period between the reinoculations. A short period after the first inoculation is followed by more marked changes, while long periods are accompanied by slight changes, which suggests an active immunisation produced by the first inoculation. More data are required, however before a definite

  13. Development of a Fluorescence-based Trypanosoma cruzi CYP51 Inhibition Assay for Effective Compound Triaging in Drug Discovery Programmes for Chagas Disease.

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    Jennifer Riley

    2015-09-01

    Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi, is a life threatening global health problem with only two drugs available for treatment (benznidazole and nifurtimox, both having variable efficacy in the chronic stage of the disease and high rates of adverse drug reactions. Inhibitors of sterol 14α-demethylase (CYP51 have proven effective against T. cruzi in vitro and in vivo in animal models of Chagas disease. Consequently two azole inhibitors of CYP51 (posaconazole and ravuconazole have recently entered clinical development by the Drugs for Neglected Diseases initiative. Further new drug treatments for this disease are however still urgently required, particularly having a different mode of action to CYP51 in order to balance the overall risk in the drug discovery portfolio. This need has now been further strengthened by the very recent reports of treatment failure in the clinic for both posaconazole and ravuconazole. To this end and to prevent enrichment of drug candidates against a single target, there is a clear need for a robust high throughput assay for CYP51 inhibition in order to evaluate compounds active against T. cruzi arising from phenotypic screens. A high throughput fluorescence based functional assay using recombinantly expressed T. cruzi CYP51 (Tulahuen strain is presented here that meets this requirement. This assay has proved valuable in prioritising medicinal chemistry resource on only those T. cruzi active series arising from a phenotypic screening campaign where it is clear that the predominant mode of action is likely not via inhibition of CYP51.

  14. Development of a Fluorescence-based Trypanosoma cruzi CYP51 Inhibition Assay for Effective Compound Triaging in Drug Discovery Programmes for Chagas Disease.

    Science.gov (United States)

    Riley, Jennifer; Brand, Stephen; Voice, Michael; Caballero, Ivan; Calvo, David; Read, Kevin D

    2015-09-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), is a life threatening global health problem with only two drugs available for treatment (benznidazole and nifurtimox), both having variable efficacy in the chronic stage of the disease and high rates of adverse drug reactions. Inhibitors of sterol 14α-demethylase (CYP51) have proven effective against T. cruzi in vitro and in vivo in animal models of Chagas disease. Consequently two azole inhibitors of CYP51 (posaconazole and ravuconazole) have recently entered clinical development by the Drugs for Neglected Diseases initiative. Further new drug treatments for this disease are however still urgently required, particularly having a different mode of action to CYP51 in order to balance the overall risk in the drug discovery portfolio. This need has now been further strengthened by the very recent reports of treatment failure in the clinic for both posaconazole and ravuconazole. To this end and to prevent enrichment of drug candidates against a single target, there is a clear need for a robust high throughput assay for CYP51 inhibition in order to evaluate compounds active against T. cruzi arising from phenotypic screens. A high throughput fluorescence based functional assay using recombinantly expressed T. cruzi CYP51 (Tulahuen strain) is presented here that meets this requirement. This assay has proved valuable in prioritising medicinal chemistry resource on only those T. cruzi active series arising from a phenotypic screening campaign where it is clear that the predominant mode of action is likely not via inhibition of CYP51. PMID:26394211

  15. Effect of extracts and isolated compounds from Chresta scapigera on viability of Leishmania amazonensis and Trypanosoma cruzi Efeito dos extratos e compostos isolados de Chresta scapigera sobre a viabilidade de Leishmania amazonensis e Trypanosoma cruzi

    OpenAIRE

    Elisandra Cristina Schinor; Marcos José Salvador; Elisabeth Mieko Furusho Pral; Silvia Celina Alfieri; Sérgio de Albuquerque; Diones Aparecida Dias

    2007-01-01

    Fractionation of bioactive crude extracts of Chresta scapigera led to the isolation of four triterpenes and five flavonoids, among them beta-amyrin acetate (1), 11alpha,12alpha-oxidetaraxeryl acetate (2) and lupeol (3), as well as the flavonoids apigenin (6), kaempferol (7), crysoeriol (8) and luteolin (9) were active against Leishmania amazonensis amastigotes-like stages, while only the flavonoids (6), (7) and (9) showed toxicity towards bloods trypomastigote forms of Trypanosoma cruzi.O fra...

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

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    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.

  17. Human mixed infections of Leishmania spp. and Leishmania-Trypanosoma cruzi in a sub Andean Bolivian area: identification by polymerase chain reaction/hybridization and isoenzyme

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    B Bastrenta

    2003-03-01

    Full Text Available Parasites belonging to Leishmania braziliensis, Leishmania donovani, Leishmania mexicana complexes and Trypanosoma cruzi (clones 20 and 39 were searched in blood, lesions and strains collected from 28 patients with active cutaneous leishmaniasis and one patient with visceral leishmaniasis. PCR-hybridization with specific probes of Leishmania complexes (L. braziliensis, L. donovani and L. mexicana and T. cruzi clones was applied to the different DNA samples. Over 29 patients, 8 (27.6% presented a mixed infection Leishmania complex species, 17 (58.6% a mixed infection Leishmania-T. cruzi, and 4 (13.8% a multi Leishmania-T. cruzi infection. Several patients were infected by the two Bolivian major clones 20 and 39 of T. cruzi (44.8%. The L. braziliensis complex was more frequently detected in lesions than in blood and a reverse result was observed for L. mexicana complex. The polymerase chain reaction-hybridization design offers new arguments supporting the idea of an underestimated rate of visceral leishmanisis in Bolivia. Parasites were isolated by culture from the blood of two patients and lesions of 10 patients. The UPGMA (unweighted pair-group method with arithmetic averages dendrogram computed from Jaccard's distances obtained from 11 isoenzyme loci data confirmed the presence of the three Leishmania complexes and undoubtedly identified human infections by L. (V. braziliensis, L. (L. chagasi and L. (L. mexicana species. Additional evidence of parasite mixtures was visualized through mixed isoenzyme profiles, L. (V. braziliensis-L. (L. mexicana and Leishmania spp.-T. cruzi.The epidemiological profile in the studied area appeared more complex than currently known. This is the first report of parasitological evidence of Bolivian patients with trypanosomatidae multi infections and consequences on the diseases' control and patient treatments are discussed.

  18. Inducible nitric oxide synthase in heart tissue and nitric oxide in serum of Trypanosoma cruzi-infected rhesus monkeys: association with heart injury.

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    Cristiano Marcelo Espinola Carvalho

    Full Text Available BACKGROUND: The factors contributing to chronic Chagas' heart disease remain unknown. High nitric oxide (NO levels have been shown to be associated with cardiomyopathy severity in patients. Further, NO produced via inducible nitric oxide synthase (iNOS/NOS2 is proposed to play a role in Trypanosoma cruzi control. However, the participation of iNOS/NOS2 and NO in T. cruzi control and heart injury has been questioned. Here, using chronically infected rhesus monkeys and iNOS/NOS2-deficient (Nos2(-/- mice we explored the participation of iNOS/NOS2-derived NO in heart injury in T. cruzi infection. METHODOLOGY: Rhesus monkeys and C57BL/6 and Nos2(-/- mice were infected with the Colombian T. cruzi strain. Parasite DNA was detected by polymerase chain reaction, T. cruzi antigens and iNOS/NOS2(+ cells were immunohistochemically detected in heart sections and NO levels in serum were determined by Griess reagent. Heart injury was assessed by electrocardiogram (ECG, echocardiogram (ECHO, creatine kinase heart isoenzyme (CK-MB activity levels in serum and connexin 43 (Cx43 expression in the cardiac tissue. RESULTS: Chronically infected monkeys presented conduction abnormalities, cardiac inflammation and fibrosis, which resembled the spectrum of human chronic chagasic cardiomyopathy (CCC. Importantly, chronic myocarditis was associated with parasite persistence. Moreover, Cx43 loss and increased CK-MB activity levels were primarily correlated with iNOS/NOS2(+ cells infiltrating the cardiac tissue and NO levels in serum. Studies in Nos2(-/- mice reinforced that the iNOS/NOS2-NO pathway plays a pivotal role in T. cruzi-elicited cardiomyocyte injury and in conduction abnormalities that were associated with Cx43 loss in the cardiac tissue. CONCLUSION: T. cruzi-infected rhesus monkeys reproduce features of CCC. Moreover, our data support that in T. cruzi infection persistent parasite-triggered iNOS/NOS2 in the cardiac tissue and NO overproduction might contribute

  19. Temporizin and Temporizin-1 Peptides as Novel Candidates for Eliminating Trypanosoma cruzi.

    Science.gov (United States)

    Souza, André L A; Faria, Robson X; Calabrese, Kátia S; Hardoim, Daiane J; Taniwaki, Noemi; Alves, Luiz A; De Simone, Salvatore G

    2016-01-01

    Tropical diseases caused by parasitic infections continue to cause socioeconomic distress worldwide. Among these, Chagas disease has become a great concern because of globalization. Caused by Trypanosoma cruzi, there is an increasing need to discover new, more effective methods to manage infections that minimize disease onset. Antimicrobial peptides represent a possible solution to this challenge. As effector molecules of the innate immune response against pathogens, they are the first line of defense found in all multi-cellular organisms. In amphibians, temporins are a large family of antimicrobial peptides found in skin secretions. Their functional roles and modes of action present unique properties that indicate possible candidates for therapeutic applications. Here, we investigated the trypanocide activity of temporizin and temporizin-1. Temporizin is an artificial, hybrid peptide containing the N-terminal region of temporin A, the pore-forming region of gramicidin and a C-terminus consisting of alternating leucine and lysine. Temporizin-1 is a modification of temporizin with a reduction in the region responsible for insertion into membranes. Their activities were evaluated in a cell permeabilization assay by flow cytometry, an LDH release assay, electron microscopy, an MTT assay and patch clamp experiments. Both temporizin and temporizin-1 demonstrated toxicity against T. cruzi with temporizin displaying slightly more potency. At concentrations up to 100 μg/ ml, both peptides exhibited low toxicity in J774 cells, a macrophage lineage cell line, and no toxicity was observed in mouse primary peritoneal macrophages. In contrast, the peptides showed some toxicity in rat adenoma GH3 cells and Jurkat human lymphoma cells with temporizin-1 displaying lower toxicity. In summary, a shortened form of the hybrid temporizin peptide, temporizin-1, was efficient at killing T. cruzi and it has low toxicity in wild-type mammalian cells. These data suggest that temporizin-1

  20. Signal transduction induced in Trypanosoma cruzi metacyclic trypomastigotes during the invasion of mammalian cells

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    N. Yoshida

    2000-03-01

    Full Text Available Penetration of Trypanosoma cruzi into mammalian cells depends on the activation of the parasite's protein tyrosine kinase and on the increase in cytosolic Ca2+ concentration. We used metacyclic trypomastigotes, the T. cruzi developmental forms that initiate infection in mammalian hosts, to investigate the association of these two events and to identify the various components of the parasite signal transduction pathway involved in host cell invasion. We have found that i both the protein tyrosine kinase activation, as measured by phosphorylation of a 175-kDa protein (p175, and Ca2+ mobilization were induced in the metacyclic forms by the HeLa cell extract but not by the extract of T. cruzi-resistant K562 cells; ii treatment of parasites with the tyrosine kinase inhibitor genistein blocked both p175 phosphorylation and the increase in cytosolic Ca2+ concentration; iii the recombinant protein J18, which contains the full-length sequence of gp82, a metacyclic stage surface glycoprotein involved in target cell invasion, interfered with tyrosine kinase and Ca2+ responses, whereas the monoclonal antibody 3F6 directed at gp82 induced parasite p175 phosphorylation and Ca2+ mobilization; iv treatment of metacyclic forms with phospholipase C inhibitor U73122 blocked Ca2+ signaling and impaired the ability of the parasites to enter HeLa cells, and v drugs such as heparin, a competitive IP3-receptor blocker, caffeine, which affects Ca2+ release from IP3-sensitive stores, in addition to thapsigargin, which depletes intracellular Ca2+ compartments and lithium ion, reduced the parasite infectivity. Taken together, these data suggest that protein tyrosine kinase, phospholipase C and IP3 are involved in the signaling cascade that is initiated on the parasite cell surface by gp82 and leads to Ca2+ mobilization required for target cell invasion.

  1. Temporizin and Temporizin-1 Peptides as Novel Candidates for Eliminating Trypanosoma cruzi.

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    André L A Souza

    Full Text Available Tropical diseases caused by parasitic infections continue to cause socioeconomic distress worldwide. Among these, Chagas disease has become a great concern because of globalization. Caused by Trypanosoma cruzi, there is an increasing need to discover new, more effective methods to manage infections that minimize disease onset. Antimicrobial peptides represent a possible solution to this challenge. As effector molecules of the innate immune response against pathogens, they are the first line of defense found in all multi-cellular organisms. In amphibians, temporins are a large family of antimicrobial peptides found in skin secretions. Their functional roles and modes of action present unique properties that indicate possible candidates for therapeutic applications. Here, we investigated the trypanocide activity of temporizin and temporizin-1. Temporizin is an artificial, hybrid peptide containing the N-terminal region of temporin A, the pore-forming region of gramicidin and a C-terminus consisting of alternating leucine and lysine. Temporizin-1 is a modification of temporizin with a reduction in the region responsible for insertion into membranes. Their activities were evaluated in a cell permeabilization assay by flow cytometry, an LDH release assay, electron microscopy, an MTT assay and patch clamp experiments. Both temporizin and temporizin-1 demonstrated toxicity against T. cruzi with temporizin displaying slightly more potency. At concentrations up to 100 μg/ ml, both peptides exhibited low toxicity in J774 cells, a macrophage lineage cell line, and no toxicity was observed in mouse primary peritoneal macrophages. In contrast, the peptides showed some toxicity in rat adenoma GH3 cells and Jurkat human lymphoma cells with temporizin-1 displaying lower toxicity. In summary, a shortened form of the hybrid temporizin peptide, temporizin-1, was efficient at killing T. cruzi and it has low toxicity in wild-type mammalian cells. These data suggest

  2. Temporizin and Temporizin-1 Peptides as Novel Candidates for Eliminating Trypanosoma cruzi

    Science.gov (United States)

    Calabrese, Kátia S.; Hardoim, Daiane J.; Taniwaki, Noemi; Alves, Luiz A.; De Simone, Salvatore G.

    2016-01-01

    Tropical diseases caused by parasitic infections continue to cause socioeconomic distress worldwide. Among these, Chagas disease has become a great concern because of globalization. Caused by Trypanosoma cruzi, there is an increasing need to discover new, more effective methods to manage infections that minimize disease onset. Antimicrobial peptides represent a possible solution to this challenge. As effector molecules of the innate immune response against pathogens, they are the first line of defense found in all multi-cellular organisms. In amphibians, temporins are a large family of antimicrobial peptides found in skin secretions. Their functional roles and modes of action present unique properties that indicate possible candidates for therapeutic applications. Here, we investigated the trypanocide activity of temporizin and temporizin-1. Temporizin is an artificial, hybrid peptide containing the N-terminal region of temporin A, the pore-forming region of gramicidin and a C-terminus consisting of alternating leucine and lysine. Temporizin-1 is a modification of temporizin with a reduction in the region responsible for insertion into membranes. Their activities were evaluated in a cell permeabilization assay by flow cytometry, an LDH release assay, electron microscopy, an MTT assay and patch clamp experiments. Both temporizin and temporizin-1 demonstrated toxicity against T. cruzi with temporizin displaying slightly more potency. At concentrations up to 100 μg/ ml, both peptides exhibited low toxicity in J774 cells, a macrophage lineage cell line, and no toxicity was observed in mouse primary peritoneal macrophages. In contrast, the peptides showed some toxicity in rat adenoma GH3 cells and Jurkat human lymphoma cells with temporizin-1 displaying lower toxicity. In summary, a shortened form of the hybrid temporizin peptide, temporizin-1, was efficient at killing T. cruzi and it has low toxicity in wild-type mammalian cells. These data suggest that temporizin-1

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

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    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.

  4. Synthesis of N1-Substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyra- zolethiocarboxamide as Novel Small Molecule Inhibitors of Cysteine Protease of T. cruzi

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A series of N1-substituted-3-aryl-4-alkyl-4, 5-dihydro-1H-1-pyrazolethiocarboxamide were prepared from the Mannich bases of aryl ketones in good yields. Some derivatives were found to be active against the cysteine protease of T.cruzi..

  5. Aspirin treatment exacerbates oral infections by Trypanosoma cruzi.

    Science.gov (United States)

    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

  6. A quinoxaline derivative as a potent chemotherapeutic agent, alone or in combination with benznidazole, against Trypanosoma cruzi.

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    Jean Henrique da Silva Rodrigues

    Full Text Available BACKGROUND: Chagas' disease is a condition caused by the protozoan Trypanosoma cruzi that affects millions of people, mainly in Latin America where it is considered endemic. The chemotherapy for Chagas disease remains a problem; the standard treatment currently relies on a single drug, benznidazole, which unfortunately induces several side effects and it is not successful in the cure of most of the chronic patients. In order to improve the drug armamentarium against Chagas' disease, in the present study we describe the synthesis of the compound 3-chloro-7-methoxy-2-(methylsulfonyl quinoxaline (quinoxaline 4 and its activity, alone or in combination with benznidazole, against Trypanosoma cruzi in vitro. METHODOLOGY/PRINCIPAL FINDINGS: Quinoxaline 4 was found to be strongly active against Trypanosoma cruzi Y strain and more effective against the proliferative forms. The cytotoxicity against LLCMK2 cells provided selective indices above one for all of the parasite forms. The drug induced very low hemolysis, but its anti-protozoan activity was partially inhibited when mouse blood was added in the experiment against trypomastigotes, an effect that was specifically related to blood cells. A synergistic effect between quinoxaline 4 and benznidazole was observed against epimastigotes and trypomastigotes, accompanied by an antagonistic interaction against LLCMK2 cells. Quinoxaline 4 induced several ultrastructural alterations, including formations of vesicular bodies, profiles of reticulum endoplasmic surrounding organelles and disorganization of Golgi complex. These alterations were also companied by cell volume reduction and maintenance of cell membrane integrity of treated-parasites. CONCLUSION/SIGNIFICANCE: Our results demonstrated that quinoxaline 4, alone or in combination with benznidazole, has promising effects against all the main forms of T. cruzi. The compound at low concentrations induced several ultrastructural alterations and led the

  7. During acute experimental infection with the reticulotropic Trypanosoma cruzi strain Tulahuen IL-22 is induced IL-23-dependently but is dispensable for protection.

    Science.gov (United States)

    Erdmann, Hanna; Behrends, Jochen; Hölscher, Christoph

    2016-01-01

    Protective immunity against Trypanosoma cruzi, the causative agent of Chagas disease, depends on the activation of macrophages by IFN-γ and IL-17A. In contrast, IL-10 prevents immunopathology. IL-22 belongs to the IL-10 cytokine family and has pleiotropic effects during host defense and immunopathology, however its role in protection and pathology during T. cruzi infection has not been analyzed yet. Therefore, we examined the role of IL-22 in experimental Chagas disease using the reticulotropic Tulahuen strain of T. cruzi. During infection, IL-22 is secreted by CD4-positive cells in an IL-23-dependent fashion. Infected IL-22(-/-) mice exhibited an increased production of IFN-γ and TNF and displayed enhanced numbers of activated IFN-γ-producing T cells in their spleens. Additionally, the production of IL-10 was increased in IL-22(-/-) mice upon infection. Macrophage activation and by association the parasitemia was not affected in the absence of IL-22. Apart from a transient increase in the body weight loss, infected IL-22(-/-) mice did not show any signs for an altered immunopathology during the first fourteen days of infection. Taken together, although IL-22 is expressed, it seems to play a minor role in protection and pathology during the acute systemic infection with the reticulotropic Tulahuen strain of T. cruzi. PMID:27650379

  8. Sequence variation in CYP51A from the Y strain of Trypanosoma cruzi alters its sensitivity to inhibition.

    Science.gov (United States)

    Cherkesova, Tatiana S; Hargrove, Tatiana Y; Vanrell, M Cristina; Ges, Igor; Usanov, Sergey A; Romano, Patricia S; Lepesheva, Galina I

    2014-11-01

    CYP51 (sterol 14α-demethylase) is an efficient target for clinical and agricultural antifungals and an emerging target for treatment of Chagas disease, the infection that is caused by multiple strains of a protozoan pathogen Trypanosoma cruzi. Here, we analyze CYP51A from the Y strain T. cruzi. In this protein, proline 355, a residue highly conserved across the CYP51 family, is replaced with serine. The purified enzyme retains its catalytic activity, yet has been found less susceptible to inhibition. These biochemical data are consistent with cellular experiments, both in insect and human stages of the pathogen. Comparative structural analysis of CYP51 complexes with VNI and two derivatives suggests that broad-spectrum CYP51 inhibitors are likely to be preferable as antichagasic drug candidates. PMID:25217832

  9. Evaluation of a chemiluminescent enzyme-linked immunosorbent assay for the diagnosis of Trypanosoma cruzi infection in a nonendemic setting

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    Luis Izquierdo

    2013-11-01

    Full Text Available The disappearance of lytic, protective antibodies (Abs from the serum of patients with Chagas disease is accepted as a reliable indicator of parasitological cure. The efficiency of a chemiluminescent enzyme-linked immunosorbent assay based on a purified, trypomastigote-derived glycosylphosphatidylinositol-anchored mucin antigen for the serologic detection of lytic Abs against Trypanosoma cruzi was evaluated in a nonendemic setting using a panel of 92 positive and 58 negative human sera. The technique proved to be highly sensitive {100%; 95% confidence interval (CI = 96-100} and specific (98.3%; 95% CI = 90.7-99.7, with a kappa score of 0.99. Therefore, this assay can be used to detect active T. cruzi infection and to monitor trypanosomicidal treatment.

  10. Altered distribution of peripheral blood memory B cells in humans chronically infected with Trypanosoma cruzi.

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    Esteban R Fernández

    Full Text Available Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

  11. Altered distribution of peripheral blood memory B cells in humans chronically infected with Trypanosoma cruzi.

    Science.gov (United States)

    Fernández, Esteban R; Olivera, Gabriela C; Quebrada Palacio, Luz P; González, Mariela N; Hernandez-Vasquez, Yolanda; Sirena, Natalia María; Morán, María L; Ledesma Patiño, Oscar S; Postan, Miriam

    2014-01-01

    Numerous abnormalities of the peripheral blood T cell compartment have been reported in human chronic Trypanosoma cruzi infection and related to prolonged antigenic stimulation by persisting parasites. Herein, we measured circulating lymphocytes of various phenotypes based on the differential expression of CD19, CD4, CD27, CD10, IgD, IgM, IgG and CD138 in a total of 48 T. cruzi-infected individuals and 24 healthy controls. Infected individuals had decreased frequencies of CD19+CD27+ cells, which positively correlated with the frequencies of CD4+CD27+ cells. The contraction of CD19+CD27+ cells was comprised of IgG+IgD-, IgM+IgD- and isotype switched IgM-IgD- memory B cells, CD19+CD10+CD27+ B cell precursors and terminally differentiated CD19+CD27+CD138+ plasma cells. Conversely, infected individuals had increased proportions of CD19+IgG+CD27-IgD- memory and CD19+IgM+CD27-IgD+ transitional/naïve B cells. These observations prompted us to assess soluble CD27, a molecule generated by the cleavage of membrane-bound CD27 and used to monitor systemic immune activation. Elevated levels of serum soluble CD27 were observed in infected individuals with Chagas cardiomyopathy, indicating its potentiality as an immunological marker for disease progression in endemic areas. In conclusion, our results demonstrate that chronic T. cruzi infection alters the distribution of various peripheral blood B cell subsets, probably related to the CD4+ T cell deregulation process provoked by the parasite in humans.

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

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    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.

  13. Perturbation of the dimer interface of triosephosphate isomerase and its effect on Trypanosoma cruzi.

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    Vanesa Olivares-Illana

    Full Text Available BACKGROUND: Chagas disease affects around 18 million people in the American continent. Unfortunately, there is no satisfactory treatment for the disease. The drugs currently used are not specific and exert serious toxic effects. Thus, there is an urgent need for drugs that are effective. Looking for molecules to eliminate the parasite, we have targeted a central enzyme of the glycolytic pathway: triosephosphate isomerase (TIM. The homodimeric enzyme is catalytically active only as a dimer. Because there are significant differences in the interface of the enzymes from the parasite and humans, we searched for small molecules that specifically disrupt contact between the two subunits of the enzyme from Trypanosoma cruzi but not those of TIM from Homo sapiens (HTIM, and tested if they kill the parasite. METHODOLOGY/PRINCIPAL FINDINGS: Dithiodianiline (DTDA at nanomolar concentrations completely inactivates recombinant TIM of T. cruzi (TcTIM. It also inactivated HTIM, but at concentrations around 400 times higher. DTDA was also tested on four TcTIM mutants with each of its four cysteines replaced with either valine or alanine. The sensitivity of the mutants to DTDA was markedly similar to that of the wild type. The crystal structure of the TcTIM soaked in DTDA at 2.15 A resolution, and the data on the mutants showed that inactivation resulted from alterations of the dimer interface. DTDA also prevented the growth of Escherichia coli cells transformed with TcTIM, had no effect on normal E. coli, and also killed T. cruzi epimastigotes in culture. CONCLUSIONS/SIGNIFICANCE: By targeting on the dimer interface of oligomeric enzymes from parasites, it is possible to discover small molecules that selectively thwart the life of the parasite. Also, the conformational changes that DTDA induces in the dimer interface of the trypanosomal enzyme are unique and identify a region of the interface that could be targeted for drug discovery.

  14. Vesicles from different Trypanosoma cruzi strains trigger differential innate and chronic immune responses

    Science.gov (United States)

    Nogueira, Paula M.; Ribeiro, Kleber; Silveira, Amanda C. O.; Campos, João H.; Martins-Filho, Olindo A.; Bela, Samantha R.; Campos, Marco A.; Pessoa, Natalia L.; Colli, Walter; Alves, Maria J. M.; Soares, Rodrigo P.; Torrecilhas, Ana Claudia

    2015-01-01

    Trypomastigote forms of Trypanosoma cruzi, the causative agent of Chagas Disease, shed extracellular vesicles (EVs) enriched with glycoproteins of the gp85/trans-sialidase (TS) superfamily and other α-galactosyl (α-Gal)-containing glycoconjugates, such as mucins. Here, purified vesicles from T. cruzi strains (Y, Colombiana, CL-14 and YuYu) were quantified according to size, intensity and concentration. Qualitative analysis revealed differences in their protein and α-galactosyl contents. Later, those polymorphisms were evaluated in the modulation of immune responses (innate and in the chronic phase) in C57BL/6 mice. EVs isolated from YuYu and CL-14 strains induced in macrophages higher levels of proinflammatory cytokines (TNF-α and IL-6) and nitric oxide via TLR2. In general, no differences were observed in MAPKs activation (p38, JNK and ERK 1/2) after EVs stimulation. In splenic cells derived from chronically infected mice, a different modulation pattern was observed, where Colombiana (followed by Y strain) EVs were more proinflammatory. This modulation was independent of the T. cruzi strain used in the mice infection. To test the functional importance of this modulation, the expression of intracellular cytokines after in vitro exposure was evaluated using EVs from YuYu and Colombiana strains. Both EVs induced cytokine production with the appearance of IL-10 in the chronically infected mice. A high frequency of IL-10 in CD4+ and CD8+ T lymphocytes was observed. A mixed profile of cytokine induction was observed in B cells with the production of TNF-α and IL-10. Finally, dendritic cells produced TNF-α after stimulation with EVs. Polymorphisms in the vesicles surface may be determinant in the immunopathologic events not only in the early steps of infection but also in the chronic phase. PMID:26613751

  15. Mir-190b negatively contributes to the Trypanosoma cruzi- infected cell survival by repressing PTEN protein expression

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    Cíntia Júnia Monteiro

    2015-12-01

    Full Text Available Chagas disease, which is caused by the intracellular protozoanTrypanosoma cruzi, is a serious health problem in Latin America. The heart is one of the major organs affected by this parasitic infection. The pathogenesis of tissue remodelling, particularly regarding cardiomyocyte behaviour after parasite infection, and the molecular mechanisms that occur immediately following parasite entry into host cells are not yet completely understood. Previous studies have reported that the establishment of parasitism is connected to the activation of the phosphatidylinositol-3 kinase (PI3K, which controls important steps in cellular metabolism by regulating the production of the second messenger phosphatidylinositol-3,4,5-trisphosphate. Particularly, the tumour suppressor PTEN is a negative regulator of PI3K signalling. However, mechanistic details of the modulatory activity of PTEN on Chagas disease have not been elucidated. To address this question, H9c2 cells were infected with T. cruzi Berenice 62 strain and the expression of a specific set of microRNAs (miRNAs were investigated. Our cellular model demonstrated that miRNA-190b is correlated to the decrease of cellular viability rates by negatively modulating PTEN protein expression in T. cruzi-infected cells.

  16. Production of cytokine and chemokines by human mononuclear cells and whole blood cells after infection with Trypanosoma cruzi

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    Karine Rezende-Oliveira

    2012-02-01

    Full Text Available INTRODUCTION: The innate immune response is the first mechanism of protection against Trypanosoma cruzi, and the interaction of inflammatory cells with parasite molecules may activate this response and modulate the adaptive immune system. This study aimed to analyze the levels of cytokines and chemokines synthesized by the whole blood cells (WBC and peripheral blood mononuclear cells (PBMC of individuals seronegative for Chagas disease after interaction with live T. cruzi trypomastigotes. METHODS: IL-12, IL-10, TNF-α, TGF-β, CCL-5, CCL-2, CCL-3, and CXCL-9 were measured by ELISA. Nitrite was determined by the Griess method. RESULTS: IL-10 was produced at high levels by WBC compared with PBMC, even after incubation with live trypomastigotes. Production of TNF-α by both PBMC and WBC was significantly higher after stimulation with trypomastigotes. Only PBMC produced significantly higher levels of IL-12 after parasite stimulation. Stimulation of cultures with trypomastigotes induced an increase of CXCL-9 levels produced by WBC. Nitrite levels produced by PBMC increased after the addition of parasites to the culture. CONCLUSIONS: Surface molecules of T. cruzi may induce the production of cytokines and chemokines by cells of the innate immune system through the activation of specific receptors not evaluated in this experiment. The ability to induce IL-12 and TNF-α contributes to shift the adaptive response towards a Th1 profile.

  17. Critical importance of the de novo pyrimidine biosynthesis pathway for Trypanosoma cruzi growth in the mammalian host cell cytoplasm

    International Nuclear Information System (INIS)

    Highlights: ► We established Trypanosoma cruzi lacking the gene for carbamoyl phosphate synthetase II. ► Disruption of the cpsII gene significantly reduced the growth of epimastigotes. ► In particular, the CPSII-null mutant severely retarded intracellular growth. ► The de novo pyrimidine pathway is critical for the parasite growth in the host cell. -- Abstract: The intracellular parasitic protist Trypanosoma cruzi is the causative agent of Chagas disease in Latin America. In general, pyrimidine nucleotides are supplied by both de novo biosynthesis and salvage pathways. While epimastigotes—an insect form—possess both activities, amastigotes—an intracellular replicating form of T. cruzi—are unable to mediate the uptake of pyrimidine. However, the requirement of de novo pyrimidine biosynthesis for parasite growth and survival has not yet been elucidated. Carbamoyl-phosphate synthetase II (CPSII) is the first and rate-limiting enzyme of the de novo biosynthetic pathway, and increased CPSII activity is associated with the rapid proliferation of tumor cells. In the present study, we showed that disruption of the T. cruzicpsII gene significantly reduced parasite growth. In particular, the growth of amastigotes lacking the cpsII gene was severely suppressed. Thus, the de novo pyrimidine pathway is important for proliferation of T. cruzi in the host cell cytoplasm and represents a promising target for chemotherapy against Chagas disease.

  18. Chemical Validation of Phosphodiesterase C as a Chemotherapeutic Target in Trypanosoma cruzi, the Etiological Agent of Chagas' Disease▿ †

    Science.gov (United States)

    King-Keller, Sharon; Li, Minyong; Smith, Alyssa; Zheng, Shilong; Kaur, Gurpreet; Yang, Xiaochuan; Wang, Binghe; Docampo, Roberto

    2010-01-01

    Trypanosoma cruzi phosphodiesterase (PDE) C (TcrPDEC), a novel and rather unusual PDE in which, unlike all other class I PDEs, the catalytic domain is localized in the middle of the polypeptide chain, is able to hydrolyze cyclic GMP (cGMP), although it prefers cyclic AMP (cAMP), and has a FYVE-type domain in its N-terminal region (S. Kunz et al., FEBS J. 272:6412-6422, 2005). TcrPDEC shows homology to the mammalian PDE4 family members. PDE4 inhibitors are currently under development for the treatment of inflammatory diseases, such as asthma, chronic pulmonary diseases, and psoriasis, and for treating depression and serving as cognitive enhancers. We therefore tested a number of compounds originally synthesized as potential PDE4 inhibitors on T. cruzi amastigote growth, and we obtained several useful hits. We then conducted homology modeling of T. cruzi PDEC and identified other compounds as potential inhibitors through virtual screening. Testing of these compounds against amastigote growth and recombinant TcrPDEC activity resulted in several potent inhibitors. The most-potent inhibitors were found to increase the cellular concentration of cAMP. Preincubation of cells in the presence of one of these compounds stimulated volume recovery after hyposmotic stress, in agreement with their TcrPDEC inhibitory activity in vitro, providing chemical validation of this target. The compounds found could be useful tools in the study of osmoregulation in T. cruzi. In addition, their further optimization could result in the development of new drugs against Chagas' disease and other trypanosomiases. PMID:20625148

  19. The Trypanosoma cruzi vitamin C dependent peroxidase confers protection against oxidative stress but is not a determinant of virulence.

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    Martin C Taylor

    2015-04-01

    Full Text Available The neglected parasitic infection Chagas disease is rapidly becoming a globalised public health issue due to migration. There are only two anti-parasitic drugs available to treat this disease, benznidazole and nifurtimox. Thus it is important to identify and validate new drug targets in Trypanosoma cruzi, the causative agent. T. cruzi expresses an ER-localised ascorbate-dependent peroxidase (TcAPx. This parasite-specific enzyme has attracted interest from the perspective of targeted chemotherapy.To assess the importance of TcAPx in protecting T. cruzi from oxidative stress and to determine if it is essential for virulence, we generated null mutants by targeted gene disruption. Loss of activity was associated with increased sensitivity to exogenous hydrogen peroxide, but had no effect on susceptibility to the front-line Chagas disease drug benznidazole. This suggests that increased oxidative stress in the ER does not play a significant role in its mechanism of action. Homozygous knockouts could proceed through the entire life-cycle in vitro, although they exhibited a significant decrease in their ability to infect mammalian cells. To investigate virulence, we exploited a highly sensitive bioluminescence imaging system which allows parasites to be monitored in real-time in the chronic stage of murine infections. This showed that depletion of enzyme activity had no effect on T. cruzi replication, dissemination or tissue tropism in vivo.TcAPx is not essential for parasite viability within the mammalian host, does not have a significant role in establishment or maintenance of chronic infections, and should therefore not be considered a priority for drug design.

  20. In vitro and in vivo investigation of the efficacy of arylimidamide DB1831 and its mesylated salt form--DB1965--against Trypanosoma cruzi infection.

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    Cristiane França da Silva

    Full Text Available Chagas disease is caused by infection with the intracellular protozoan parasite Trypanosoma cruzi. At present, nifurtimox and benznidazole, both compounds developed empirically over four decades ago, represent the chemotherapeutic arsenal for treating this highly neglected disease. However, both drugs present variable efficacy depending on the geographical area and the occurrence of natural resistance, and are poorly effective against the later chronic stage. As a part of a search for new therapeutic opportunities to treat chagasic patients, pre-clinical studies were performed to characterize the activity of a novel arylimidamide (AIA--DB1831 (hydrochloride salt and DB1965 (mesylate salt against T. cruzi. These AIAs displayed a high trypanocidal effect in vitro against both relevant forms in mammalian hosts, exhibiting a high selectivity index and a very high efficacy (IC(50 value/48 h of 5-40 nM against intracellular parasites. DB1965 shows high activity in vivo in acute experimental models (mouse of T. cruzi, showing a similar effect to benznidazole (Bz when compared under a scheme of 10 daily consecutive doses with 12.5 mg/kg. Although no parasitological cure was observed after treating with 20 daily consecutive doses, a combined dosage of DB1965 (5 mg/kg with Bz (50 mg/kg resulted in parasitaemia clearance and 100% animal survival. In summary, our present data confirmed that aryimidamides represent promising new chemical entities against T. cruzi in therapeutic schemes using the AIA alone or in combination with other drugs, like benznidazole.

  1. Effects of medicinal plant extracts on growth of Leishmania (L. amazonensis and Trypanosoma cruzi Efeito de extratos de plantas medicinais no crescimento de Leishmania (L. amazonensis e Trypanosoma cruzi

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    Patrícia Shima Luize

    2005-03-01

    Full Text Available This study describes the screening of extracts obtained from 19 species of plants used in Brazilian traditional medicine for treatment of a variety of diseases. The extracts were tested against axenic amastigote and promastigote forms of Leishmania (L. amazonensis, and epimastigote forms of Trypanosoma cruzi in vitro at a concentration of 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, and Tanacetum vulgare showed significant effects against one or both parasites, with a percentage of growth inhibition between 49.5 and 99%. The extracts showed no cytotoxic effect on sheep erythrocytes. These medicinal plants may be sources of new compounds that are clinically active against L. amazonensis and T. cruzi.Este estudo descreve a triagem de extratos obtidos de 19 espécies de plantas usadas na medicina tradicional brasileira para o tratamento de várias doenças. Os extratos foram testados contra formas amastigota axênica e promastigota de Leishmania (L. amazonensis, e formas epimastigota de Trypanosoma cruzi in vitro na concentração de 100 mg/ml. Baccharis trimera, Cymbopogon citratus, Matricaria chamomilla, Mikania glomerata, Ocimum gratissimum, Piper regnellii, Prunus domestica, Psidium guajava, Sambucus canadensis, Stryphnodendron adstringens, Tanacetum parthenium, e Tanacetum vulgare apresentaram efeito significante contra um ou ambos parasitas, com a porcentagem de inibição de crescimento entre 49,5 e 99%. Os extratos não mostraram efeito citotóxico em hemácias de carneiro. Essas plantas medicinais podem ser fontes alternativas de novos compostos clinicamente ativos contra L. amazonensis e T. cruzi.

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

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    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.

  3. Production of amastigotes from metacyclic trypomastigotes of Trypanosoma cruzi

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    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  7. DL-alpha-difluoromethylarginine inhibits intracellular Trypanosoma cruzi multiplication by affecting cell division but not trypomastigote-amastigote transformation.

    Science.gov (United States)

    Yakubu, M A; Basso, B; Kierszenbaum, F

    1992-06-01

    DL-alpha-difluoromethylarginine (DFMA), a specific, irreversible inhibitor of arginine decarboxylase (ADC), decreases the capacity of Trypanosoma cruzi to invade and multiply within different types of mammalian host cells in vitro. In this work we found that inhibition of intracellular growth results from selective impairment of amastigote division without appreciable alteration of the capacity of the invading trypomastigotes to transform into the replicative amastigote form. Addition of agmatine, the product of arginine decarboxylation, reversed the inhibitory effect of DFMA. Inhibition of ornithine decarboxylase activity by DL-alpha-difluoromethylornithine present in the medium prior to and during infection did not affect trypomastigote transformation or amastigote replication and did not change the magnitude of the inhibitory effect of DFMA on parasite multiplication. Hence, neither polyamine synthesis via the ornithine decarboxylase pathway nor salvage of host cell polyamines by T. cruzi appeared to be a likely explanation for the normal rate of parasite transformation that was seen in the presence of DFMA. Two clones of T. cruzi, TMSU-1 and TMSU-2, were tested for their degrees of sensitivity to the inhibitory effects of DFMA. Both trypomastigote association with (i.e., binding to and penetration of) myoblasts, and intracellular amastigote multiplication by either clone were found to be significantly (P less than 0.05) but not completely inhibited by DFMA. Therefore, the partial inhibition of T. cruzi infectivity and replication caused by DFMA is unlikely to represent a composite of effects of the drug on DFMA-sensitive and insensitive clones.(ABSTRACT TRUNCATED AT 250 WORDS)

  8. Modulation of Cell Sialoglycophenotype: A Stylish Mechanism Adopted by Trypanosoma cruzi to Ensure Its Persistence in the Infected Host

    Science.gov (United States)

    Freire-de-Lima, Leonardo; da Fonseca, Leonardo M.; da Silva, Vanessa A.; da Costa, Kelli M.; Morrot, Alexandre; Freire-de-Lima, Célio G.; Previato, Jose O.; Mendonça-Previato, Lucia

    2016-01-01

    Trypanosoma cruzi, the etiological agent of Chagas disease exhibits multiple mechanisms to guarantee its establishment and persistence in the infected host. It has been well demonstrated that T. cruzi is not able to synthesize sialic acids (Sia). To acquire the monosaccharide, the parasite makes use of a multifunctional enzyme called trans-sialidase (Tc-TS). Since this enzyme has no analogous in the vertebrate host, it has been used as a target in drug therapy development. Tc-TS preferentially catalyzes the transfer of Sia from the host glycoconjugates to the terminal β-galactopyranosyl residues of mucin-like molecules present on the parasite’s cell surface. Alternatively, the enzyme can sialylate/re-sialylate glycoconjugates expressed on the surface of host cells. Since its discovery, several studies have shown that T. cruzi employs the Tc-TS activity to modulate the host cell sialoglycophenotype, thus favoring its perpetuation in the infected vertebrate. In this review, we summarize the dynamic of host/parasite sialoglycophenotype modulation, highlighting its role in the subversion of host immune response in order to promote the establishment of persistent chronic infection. PMID:27242722

  9. Binding mode and potency of N-indolyloxopyridinyl-4-aminopropanyl-based inhibitors targeting Trypanosoma cruzi CYP51.

    Science.gov (United States)

    Vieira, Debora F; Choi, Jun Yong; Calvet, Claudia M; Siqueira-Neto, Jair Lage; Johnston, Jonathan B; Kellar, Danielle; Gut, Jiri; Cameron, Michael D; McKerrow, James H; Roush, William R; Podust, Larissa M

    2014-12-11

    Chagas disease is a chronic infection in humans caused by Trypanosoma cruzi and manifested in progressive cardiomyopathy and/or gastrointestinal dysfunction. Limited therapeutic options to prevent and treat Chagas disease put 8 million people infected with T. cruzi worldwide at risk. CYP51, involved in the biosynthesis of the membrane sterol component in eukaryotes, is a promising drug target in T. cruzi. We report the structure-activity relationships (SAR) of an N-arylpiperazine series of N-indolyloxopyridinyl-4-aminopropanyl-based inhibitors designed to probe the impact of substituents in the terminal N-phenyl ring on binding mode, selectivity and potency. Depending on the substituents at C-4, two distinct ring binding modes, buried and solvent-exposed, have been observed by X-ray structure analysis (resolution of 1.95-2.48 Å). The 5-chloro-substituted analogs 9 and 10 with no substituent at C-4 demonstrated improved selectivity and potency, suppressing ≥ 99.8% parasitemia in mice when administered orally at 25 mg/kg, b.i.d., for 4 days. PMID:25393646

  10. 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

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    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.

  11. Screening of Trypanosoma cruzi glycosomal glyceraldehyde-3-phosphate dehydrogenase enzyme inhibitors

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    Ana C. Leite

    2009-03-01

    Full Text Available The inhibitory activity of crude extracts of Meliaceae and Rutaceae plants on glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH enzyme from Trypanosoma cruzi was evaluated at 100 μg/mL. Forty-six extracts were tested and fifteen of them showed significant inhibitory activity (IA % > 50. The majority of the assayed extracts of Meliaceae plants (Cedrela fissilis, Cipadessa fruticosa and Trichilia ramalhoi showed high ability to inhibit the enzymatic activity. The fractionation of the hexane extract from branches of C. fruticosa led to the isolation of three flavonoids: flavone, 7-methoxyflavone and 3',4',5',5,7-pentamethoxyflavone. The two last compounds showed high ability to inhibit the gGAPDH activity. Therefore, the assayed Meliaceae species could be considered as a promising source of lead compounds against Chagas' disease.

  12. Treatment of chronically Trypanosoma cruzi-infected mice with a CCR1/CCR5 antagonist (Met-RANTES) results in amelioration of cardiac tissue damage.

    Science.gov (United States)

    Medeiros, Gabriela A; Silvério, Jaline C; Marino, Ana Paula M P; Roffê, Ester; Vieira, Valeska; Kroll-Palhares, Karina; Carvalho, Cristiano E; Silva, Andréa Alice; Teixeira, Mauro M; Lannes-Vieira, Joseli

    2009-02-01

    The comprehension of the molecular mechanisms leading to Trypanosoma cruzi-elicited heart dysfunction might contribute to design novel therapeutic strategies aiming to ameliorate chronic Chagas disease cardiomyopathy. In C3H/He mice infected with the low virulence T. cruzi Colombian strain, the persistent cardiac inflammation composed mainly of CCR5(+) T lymphocytes parallels the expression of CC-chemokines in a pro-inflammatory IFN-gamma and TNF-alpha milieu. The chronic myocarditis is accompanied by increased frequency of peripheral CCR5(+)LFA-1(+) T lymphocytes. The treatment of chronically T. cruzi-infected mice with Met-RANTES, a selective CCR1/CCR5 antagonist, led to a 20-30% decrease in CD4(+) cell numbers as well as IL-10, IL-13 and TNF-alpha expression. Further, Met-RANTES administration impaired the re-compartmentalization of the activated CD4(+)CCR5(+) lymphocytes. Importantly, Met-RANTES treatment resulted in significant reduction in parasite load and fibronectin deposition in the heart tissue. Moreover, Met-RANTES treatment significantly protected T. cruzi-infected mice against connexin 43 loss in heart tissue and CK-MB level enhancement, markers of heart dysfunction. Thus, our results corroborate that therapeutic strategies based on the modulation of CCR1/CCR5-mediated cell migration and/or effector function may contribute to cardiac tissue damage limitation during chronic Chagas disease.

  13. Trypanosoma cruzi: Transporte de metabolitos esenciales obtenidos del hospedador Trypanosoma cruzi: Transport of essential metabolites acquired from the host

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    Claudio A. Pereira

    2008-10-01

    Full Text Available El Trypanosoma cruzi es el agente causal de la enfermedad de Chagas, endémica en Argentina y en toda América Latina. Presenta numerosas características metabólicas diferenciales respecto a sus hospedadores insectos y mamíferos. Algunas de estas diferencias fueron consecuencia de millones de años de adaptación al parasitismo en los cuales estos organismos protozoarios reemplazaron, a lo largo de su evolución, muchas rutas metabólicas de biosíntesis por sistemas de transporte de metabolitos desde el hospedador. En esta revisión se describen los avances en el conocimiento de los sistemas de transporte tanto bioquímicos como también de las moléculas involucradas en dichos procesos. Se aborda con especial énfasis los transportadores de aminoácidos y poliaminas de T. cruzi de la familia AAAP (Amino Acid/Auxin Permeases ya que parece ser exclusiva de los tripanosomátidos. Teniendo en cuenta que estas moléculas se encuentran completamente ausentes en mamíferos podrían ser consideradas como potenciales blancos contra el Trypanosoma cruzi.Trypanosoma cruzi is the etiological agent of Chagas disease, a disease endemic not only in Argentina but also in all of Latinamerica. T. cruzi presents several metabolic characteristics which are completely absent in its insect vectors and in mammalian hosts. Some of these differences were acquired after millions of years of adaptation to parasitism, during which this protozoan replaced many biosynthetic routes for transport systems. In the present review, we describe the advances in the knowledge of T. cruzi transport processes and the molecules involved. In particular, we focus on aminoacid and polyamine transporters from the AAAP family (Amino Acid/Auxin Permeases, because they seem to be exclusive transporters from trypanosomatids. Taking into account that these permeases are completely absent in mammals, they could be considered as a potential target against Trypanosoma cruzi.

  14. Role of membrane-bound IgM in Trypanosoma cruzi evasion from immune clearance.

    Science.gov (United States)

    Garcia, I E; Lima, M R; Marinho, C R; Kipnis, T L; Furtado, G C; Alvarez, J M

    1997-04-01

    We have recently described that Trypanosoma cruzi parasites of the reticulotropic Y strain increase their resistance to antibody-induced clearance during their interaction with the vertebrate host immune system. In the present study, we observed that trypomastigotes of the myotropic CL strain isolated from normal host also display an increased resistance to immune clearance when compared to parasites obtained from immunosuppressed donors. Through fluorescence-activated cell sorting analysis, we have observed that the high expression of membrane-bound IgM antibodies on Y and CL trypomastigotes correlates with their enhanced resistance to Ig-induced clearance. Trypomastigotes from normal mice were essentially refractory to the in vitro binding of immunoglobulins, showing that their membrane structures were completely covered by IgM antibodies. These findings suggest that this isotype does not efficiently mediate immune clearance. Moreover, membrane-bound IgM antibodies limited the amount of IgG attached to the parasite and, as a consequence, impaired efficient immune clearance. Through this mechanism, trypomastigotes of T. cruzi could increase their persistence in the bloodstream thus favoring parasite transmission to its hematophagous host vector in the early acute phase of the disease.

  15. In vitro activity of 2-pyridinecarboxylic acid against trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus = Atividade in vitro do ácido 2-piridinocarboxílico em tripanossoma do subgênero Schizotrypanum isolado do morcego Phyllostomus hastatus

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    Paulo Roberto Ceridóreo Corrêa

    2011-09-01

    Full Text Available The effect of 2-pyridinecarboxylic acid (picolinic acid on trypanosomes of the subgenus Schizotrypanum isolated from the bat Phyllostomus hastatus was determined in this study. Picolinic acid, at 50 ƒÊg mL-1, inhibited epimastigote growth by 99% after 12 days incubation. In addition, trypomastigote motility decreased by 50% after 6h and completely after 24h in the presence of 50 ƒÊg mL-1 picolinic acid. The 50% cytotoxic concentration on HEp-2 cell line was275 ƒÊg mL-1 after 4 days incubation. Altogether, these results indicate higher toxicity against trypanosomes. The inhibitory effect of picolinic acid on epimastigote growth can be partially reversed by nicotinic acid and L-tryptophan, suggesting a competitive inhibition. Furthermore, two anti-Trypanosoma (Schizotrypanum cruzi drugs were also evaluated with regard to bat trypanosome growth. Benznidazole, at 50 ƒÊg mL-1, inhibited epimastigote growth by 90% after 12 days incubation. Nifurtimox, at the same concentration, caused 96% growth inhibition after four days incubation. Corroborating a previous study, bat trypanosomes are a good model for screening new trypanocidal compounds. Moreover, they can be used to study many biological processes common to human pathogenic trypanosomatids.O efeito do acido 2- piridinocarboxilico (acido picolinico sobre um tripanossoma do subgenero Schizotrypanum isolado do morcego Phyllostomus hastatus foi determinado neste estudo. O acido picolinico, na concentracao de 50 ƒÊg mL-1, inibiu 99% do crescimento de epimastigotas apos 12 dias de incubacao. Alem disso, houve um decrescimo de 50 e 100% na mobilidade dos tripomastigotas apos 6 e 24h, respectivamente, em presenca de acido picolinico na concentracao de 50 ƒÊg mL-1. A concentracao citotoxica 50% para celulas HEp-2 foi de 275 ƒÊg mL-1 apos quatro dias de incubacao. Esses resultados indicam maior toxicidade contra os tripanossomas. O efeito inibitoriodo acido picolinico sobre o crescimento de

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

    OpenAIRE

    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 ...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

  19. Investigação de anticorpos contra Sarcocystis neurona e Sarcocystis cruzi em equinos

    OpenAIRE

    A. M. Antonello; F. L. Pivoto; G Camillo; Braunig, P; L.A. Sangioni; E. Pompermayer; Venturini, M. C.; F.S.F. Vogel

    2015-01-01

    ABSTRACTSarcocystis neurona is the primary agent for Equine Protozoal Myeloencephalitis (EPM), important neurological disease characterized by behavior or muscular changes, that impairs animal performance and husbandry. Sarcocystis cruzi is a pathogen related to myositis in cattle. Although related the life cycles of the parasites are distinct. S. neurona has opossums (Didelphis spp.) and S. cruzi, dogs as definitive hosts. However, S. neurona and S. cruzi may undergo cross-reactivity in sero...

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

    OpenAIRE

    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...

  1. Development of a Novel Multiplex Immunoassay Multi-cruzi for the Serological Confirmation of Chagas Disease

    OpenAIRE

    Granjon, Elodie; Dichtel-Danjoy, Marie-Laure; Saba, Esber; Sabino, Ester; Campos de Oliveira, Lea; Zrein, Maan

    2016-01-01

    Background Chagas disease is due to the parasite Trypanosoma cruzi, a protist disseminated by a Triatome vector. This disease is endemic to Latin America and considered by WHO as one of the 17 world’s neglected diseases. In Europe and in North America, imported cases are also detected, due to migration of population outside of the endemic region. Diagnosis of T. cruzi infection is usually made indirectly by the detection of specific antibodies to T. cruzi antigens. Following initial diagnosti...

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

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    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.

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

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    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

  4. Trypanosoma cruzi infection induces up-regulation of cardiac muscarinic acetylcholine receptors in vivo and in vitro

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    K. Peraza-Cruces

    2008-09-01

    Full Text Available The pathogenesis of chagasic cardiomyopathy is not completely understood, but it has been correlated with parasympathetic denervation (neurogenic theory and inflammatory activity (immunogenic theory that could affect heart muscarinic acetylcholine receptor (mAChR expression. In order to further understand whether neurogenic and/or immunogenic alterations are related to changes in mAChR expression, we studied two models of Trypanosoma cruzi infection: 1 in 3-week-old male Sprague Dawley rats chronically infected with T. cruzi and 2 isolated primary cardiomyocytes co-cultured with T. cruzi and peripheral blood mononuclear cells (PBMC. Using [³H]-quinuclidinylbenzilate ([³H]-QNB binding assays, we evaluated mAChR expression in homogenates from selected cardiac regions, PBMC, and cultured cardiomyocytes. We also determined in vitro protein expression and pro-inflammatory cytokine expression in serum and cell culture medium by ELISA. Our results showed that: 1 mAChR were significantly (P < 0.05 up-regulated in right ventricular myocardium (means ± SEM; control: 58.69 ± 5.54, N = 29; Chagas: 72.29 ± 5.79 fmol/mg, N = 34 and PBMC (control: 12.88 ± 2.45, N = 18; Chagas: 20.22 ± 1.82 fmol/mg, N = 19, as well as in cardiomyocyte transmembranes cultured with either PBMC/T. cruzi co-cultures (control: 24.33 ± 3.83; Chagas: 43.62 ± 5.08 fmol/mg, N = 7 for both or their conditioned medium (control: 37.84 ± 3.84, N = 4; Chagas: 54.38 ± 6.28 fmol/mg, N = 20; 2 [³H]-leucine uptake was increased in cardiomyocytes co-cultured with PBMC/T. cruzi-conditioned medium (Chagas: 21,030 ± 2321; control 10,940 ± 2385 dpm, N = 7 for both; P < 0.05; 3 plasma IL-6 was increased in chagasic rats, IL-1β, was increased in both plasma of chagasic rats and in the culture medium, and TNF-α level was decreased in the culture medium. In conclusion, our results suggest that cytokines are involved in the up-regulation of mAChR in chronic Chagas disease.

  5. Proteomic Analysis of Trypanosoma cruzi Epimastigotes Subjected to Heat Shock

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    Deyanira Pérez-Morales

    2012-01-01

    Full Text Available Trypanosoma cruzi is exposed to sudden temperature changes during its life cycle. Adaptation to these variations is crucial for parasite survival, reproduction, and transmission. Some of these conditions may change the pattern of genetic expression of proteins involved in homeostasis in the course of stress treatment. In the present study, the proteome of T. cruzi epimastigotes subjected to heat shock and epimastigotes grow normally was compared by two-dimensional gel electrophoresis followed by mass spectrometry for protein identification. Twenty-four spots differing in abundance were identified. Of the twenty-four changed spots, nineteen showed a greater intensity and five a lower intensity relative to the control. Several functional categories of the identified proteins were determined: metabolism, cell defense, hypothetical proteins, protein fate, protein synthesis, cellular transport, and cell cycle. Proteins involved in the interaction with the cellular environment were also identified, and the implications of these changes are discussed.

  6. Electron Microscopy Analysis of the Nucleolus of Trypanosoma cruzi

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    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.

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

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    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. Action of the medicine Canova® on peritoneal resident macrophages infected with Trypanosoma cruzi = Ação do medicamento Canova® em macrófagos peritoniais residentes infectados por Trypanosoma cruzi

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    Vanessa Tagawa Cardoso de Oliveira

    2008-01-01

    Full Text Available Approximately 20 million of people are chronically infected withTrypanosoma cruzi in Latin America. The present work investigated the action of the homeopathic medicine Canova® on in vitro experimental infections with T. cruzi Y strain, using Swiss mice resident peritoneal macrophages. Our results demonstrated that Canova®induced a decrease in the production of H2O2 and TNF-a at 20 and 40% concentrations when compared to the control RPMI. However, when compared with this medicine excipient, a significant decrease in these mediators was observed with Canova® at 40% concentration only. The production of NO and phagocytic activity were not affected. TNF-a inhibits T. cruzi replication in peritoneal macrophages in vitro, becoming an important agent of infection control by this parasite. Within this context, Canova®, unlike what has been reported with other infections, would function as a stimulator of the infection, since it inhibited the production of TNF-α by peritoneal resident macrophages in vitro. Further studies should be carried out with elicited macrophages, in order to confirm the inhibitoryactivity of Canova® on the production of TNF-α and other mediators in macrophages infected by T. cruzi.Aproximadamente 20 milhões de pessoas são cronicamente infectadas pelo Trypanosoma cruzi na América Latina. O presente trabalhoinvestigou a ação do medicamento homeopático Canova® em infecções experimentais “in vitro” com Trypanosoma cruzi, cepa Y, usando macrófagos residentes peritoniais de camundongos Swiss. Os resultados indicaram que Canova® induz a diminuição significativa da produção de H2O2 e TNF-α em concentrações de 20 e 40%, quando comparado com ocontrole RPMI. Quando comparado com o excipiente do medicamento, observou-se diminuição na concentração destes mediadores apenas na concentração de 40%. A produção de NO e a atividade fagocítica não foram afetadas. TNF-α inibe a replicação do protozoário em

  9. The effect of Bulgarian propolis against Trypanosoma cruzi and during its interaction with host cells

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    Andréia Pires Dantas

    2006-03-01

    Full Text Available Propolis has shown activity against pathogenic microorganisms that cause diseases in humans and animals. The ethanol (Et-Blg and acetone (Ket-Blg extracts from a Bulgarian propolis, with known chemical compositions, presented similar activity against tissue culture-derived amastigotes. The treatment of Trypanosoma cruzi-infected skeletal muscle cells with Et-Blg led to a decrease of infection and of the intracellular proliferation of amastigotes, while damage to the host cell was observed only at concentration 12.5 times higher than those affecting the parasite. Ultrastructural analysis of the effect of both extracts in epimastigotes revealed that the main targets were the mitochondrion and reservosomes. Et-Blg also affected the mitochondrion-kinetoplast complex in trypomastigotes, offering a potential target for chemotherapeutic agents.

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

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    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

  11. Optimized multilocus sequence typing (MLST scheme for Trypanosoma cruzi.

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    Patricio Diosque

    2014-08-01

    Full Text Available Trypanosoma cruzi, the aetiological agent of Chagas disease possess extensive genetic diversity. This has led to the development of a plethora of molecular typing methods for the identification of both the known major genetic lineages and for more fine scale characterization of different multilocus genotypes within these major lineages. Whole genome sequencing applied to large sample sizes is not currently viable and multilocus enzyme electrophoresis, the previous gold standard for T. cruzi typing, is laborious and time consuming. In the present work, we present an optimized Multilocus Sequence Typing (MLST scheme, based on the combined analysis of two recently proposed MLST approaches. Here, thirteen concatenated gene fragments were applied to a panel of T. cruzi reference strains encompassing all known genetic lineages. Concatenation of 13 fragments allowed assignment of all strains to the predicted Discrete Typing Units (DTUs, or near-clades, with the exception of one strain that was an outlier for TcV, due to apparent loss of heterozygosity in one fragment. Monophyly for all DTUs, along with robust bootstrap support, was restored when this fragment was subsequently excluded from the analysis. All possible combinations of loci were assessed against predefined criteria with the objective of selecting the most appropriate combination of between two and twelve fragments, for an optimized MLST scheme. The optimum combination consisted of 7 loci and discriminated between all reference strains in the panel, with the majority supported by robust bootstrap values. Additionally, a reduced panel of just 4 gene fragments displayed high bootstrap values for DTU assignment and discriminated 21 out of 25 genotypes. We propose that the seven-fragment MLST scheme could be used as a gold standard for T. cruzi typing, against which other typing approaches, particularly single locus approaches or systematic PCR assays based on amplicon size, could be compared.

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

    OpenAIRE

    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...

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

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    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.

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

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    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.

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

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    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

  16. Regulation and use of the extracellular matrix by Trypanosoma cruzi during early infection

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    Pius N. Nde

    2012-11-01

    Full Text Available Chagas disease, which was once thought to be confined to endemic regions of Latin America, has now gone global becoming a new worldwide challenge. For more than a century since its discovery, it has remained neglected with no effective drugs or vaccines. The mechanisms by which Trypanosoma cruzi regulates and uses the extracellular matrix to invade cells and cause disease are just beginning to be understood. Here we critically review and discuss the regulation of the extracellular matrix (ECM interactome by T. cruzi, the use of the ECM by T. cruzi and analyze the molecular ECM/T. cruzi interphase during the early process of infection. It has been shown that invasive trypomastigote forms of T. cruzi use and modulate components of the ECM during the initial process of infection. Infective trypomastigotes up-regulate the expression of laminin γ-1 (LAMC1 and thrombospondin (THBS1 to facilitate the recruitment of trypomastigotes to enhance cellular infection. Silencing the expression of LAMC1 and THBS1 by stable RNAi dramatically reduces trypanosome infection. T. cruzi gp83, a ligand that mediates the attachment of trypanosomes to cells to initiate infection, up-regulates LAMC1 expression to enhance cellular infection. Infective trypomastigotes use Tc85 to interact with laminin, p45 mucin to interact with LAMC1 through galectin-3 (LGALS3, a human lectin, and calreticulin (TcCRT to interact with TSB1 to enhance cellular infection. Silencing the expression of LGALS3 also reduces cellular infection. Despite the role of the ECM in T. cruzi infection, almost nothing is known about the ECM interactome networks operating in the process of T. cruzi infection and its ligands. Here, we present the first elucidation of the human ECM interactome network regulated by T. cruzi and its gp83 ligand that facilitates cellular infection. The elucidation of the human ECM interactome regulated by T. cruzi and the dissection of the molecular ECM/T. cruzi interphase using

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

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

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    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

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

    Science.gov (United States)

    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

  20. The Trypanosoma cruzi Sylvio X10 strain maxicircle sequence: the third musketeer

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    Sturm Nancy R

    2011-01-01

    Full Text Available Abstract Background Chagas disease has a diverse pathology caused by the parasite Trypanosoma cruzi, and is indigenous to Central and South America. A pronounced feature of the trypanosomes is the kinetoplast, which is comprised of catenated maxicircles and minicircles that provide the transcripts involved in uridine insertion/deletion RNA editing. T. cruzi exchange genetic material through a hybridization event. Extant strains are grouped into six discrete typing units by nuclear markers, and three clades, A, B, and C, based on maxicircle gene analysis. Clades A and B are the more closely related. Representative clade B and C maxicircles are known in their entirety, and portions of A, B, and C clades from multiple strains show intra-strain heterogeneity with the potential for maxicircle taxonomic markers that may correlate with clinical presentation. Results To perform a genome-wide analysis of the three maxicircle clades, the coding region of clade A representative strain Sylvio X10 (a.k.a. Silvio X10 was sequenced by PCR amplification of specific fragments followed by assembly and comparison with the known CL Brener and Esmeraldo maxicircle sequences. The clade A rRNA and protein coding region maintained synteny with clades B and C. Amino acid analysis of non-edited and 5'-edited genes for Sylvio X10 showed the anticipated gene sequences, with notable frameshifts in the non-edited regions of Cyb and ND4. Comparisons of genes that undergo extensive uridine insertion and deletion display a high number of insertion/deletion mutations that are likely permissible due to the post-transcriptional activity of RNA editing. Conclusion Phylogenetic analysis of the entire maxicircle coding region supports the closer evolutionary relationship of clade B to A, consistent with uniparental mitochondrial inheritance from a discrete typing unit TcI parental strain and studies on smaller fragments of the mitochondrial genome. Gene variance that can be corrected

  1. Trypanocidal activity of flavonoids and limonoids isolated from Myrsinaceae and Meliaceae active plant extracts

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    Ana C. Leite

    2010-03-01

    Full Text Available The activity of crude extracts of three Rapanea species (Myrsinaceae and Cipadessa fruticosa (Meliaceae was evaluated in vitro against the trypomastigote forms of Trypanosoma cruzi. Thirty-three extracts from different organs of these species were assayed and eleven of them showed significant activity (lysis % >50. The fractionation of an active extract from branches of R. lancifolia (99.5% led to the isolation of two flavonoids: quercetin and taxifolin, which have weak trypanocidal activity. Additionally, one active extract from fruits of C. fruticosa (97.7% afforded mexicanolide limonoids: cipadesin, mexicanolide, febrifugin and cipadesin A, that were slightly active on T. cruzi. Moreover, other two flavonoids (flavone and 7-methoxyflavone, previously assayed against T. cruzi, were isolated from the hexane extract from branches of C. fruticosa (100%. The results presented here suggest that the plants evaluated could be a source of new active compounds against T. cruzi.

  2. Trypanosoma cruzi III from armadillos (Dasypus novemcinctus novemcinctus) from Northeastern Venezuela and its biological behavior in murine model. Risk of emergency of Chagas' disease.

    Science.gov (United States)

    Morocoima, Antonio; Carrasco, Hernán J; Boadas, Johanna; Chique, José David; Herrera, Leidi; Urdaneta-Morales, Servio

    2012-11-01

    Trypanosoma cruzi, etiological agent of Chagas' disease, was isolated from armadillos (Dasypus novemcinctus novemcinctus) captured in rural communities Northeastern Venezuela from Nueva Esparta State (no endemic for Chagas' disease), Monagas and Anzoátegui States (endemics). The isolates, genetically typed by PCR-RFLP as belonging to the TcIII DTU, have demonstrated in murine model heterogenic parasitemia, mortality and histotropism with marked parasitism in cardiac, skeletal, and smooth myocytes that showed correlation with lymphobasophilic inflammatory infiltrates. Our finding of T. cruzi infected armadillos in Isla Margarita (Nueva Esparta State), together with reports of triatomine vectors in this region, the accentuated synanthropy of armadillos, intense economic activity, migration due to tourism and the lack of environmental education programs all of them represent risks that could cause the emergence of Chagas' disease in this area. This is the first report of the TcIII DTU in Northeastern Venezuela, thus widening the geographic distribution of this DTU. PMID:22902748

  3. Trypanosoma cruzi as an effective cancer antigen delivery vector.

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    Junqueira, Caroline; Santos, Luara I; Galvão-Filho, Bruno; Teixeira, Santuza M; Rodrigues, Flávia G; DaRocha, Wanderson D; Chiari, Egler; Jungbluth, Achim A; Ritter, Gerd; Gnjatic, Sacha; Old, Lloyd J; Gazzinelli, Ricardo T

    2011-12-01

    One of the main challenges in cancer research is the development of vaccines that induce effective and long-lived protective immunity against tumors. Significant progress has been made in identifying members of the cancer testis antigen family as potential vaccine candidates. However, an ideal form for antigen delivery that induces robust and sustainable antigen-specific T-cell responses, and in particular of CD8(+) T lymphocytes, remains to be developed. Here we report the use of a recombinant nonpathogenic clone of Trypanosoma cruzi as a vaccine vector to induce vigorous and long-term T cell-mediated immunity. The rationale for using the highly attenuated T. cruzi clone was (i) the ability of the parasite to persist in host tissues and therefore to induce a long-term antigen-specific immune response; (ii) the existence of intrinsic parasite agonists for Toll-like receptors and consequent induction of highly polarized T helper cell type 1 responses; and (iii) the parasite replication in the host cell cytoplasm, leading to direct antigen presentation through the endogenous pathway and consequent induction of antigen-specific CD8(+) T cells. Importantly, we found that parasites expressing a cancer testis antigen (NY-ESO-1) were able to elicit human antigen-specific T-cell responses in vitro and solid protection against melanoma in a mouse model. Furthermore, in a therapeutic protocol, the parasites expressing NY-ESO-1 delayed the rate of tumor development in mice. We conclude that the T. cruzi vector is highly efficient in inducing T cell-mediated immunity and protection against cancer cells. More broadly, this strategy could be used to elicit a long-term T cell-mediated immunity and used for prophylaxis or therapy of chronic infectious diseases.

  4. Life cycle of Trypanosoma cruzi (y strain in mice

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    Pinto Pedro Luiz Silva

    1999-01-01

    Full Text Available Since 1958, we have studied experimental Chagas' disease (CD by subcutaneous inoculation of 1,000 blood forms of Trypanosoma cruzi (Y strain in Balb/C. mice. Evolution of parasitemia remained constant, beginning on the 5th and 6th day of the disease, increasing progressively, achieving a maximum on about the 30th day. After another month, only a few forms were present, and they disappeared from the circulation after the third month, as determined from direct examination of slides and the use of a Neubauer Counting Chamber. These events coincided with the appearance of amastigote nests in the tissues (especially the cardiac ones, starting the first week, and following the Gauss parasitemia curve, but they were not in parallel until the chronic stage. In 1997, we began to note the following changes: Parasites appeared in the circulation during the first week and disappeared starting on the 7th day, and there was a coincident absence of the amastigote nests in the tissues. A careful study verified that young forms in the evolutionary cycle of T. cruzi (epi + amastigotes began to appear alongside the trypomastigotes in the circulation on the 5th and 7th post-inoculation day. At the same time, rounded, oval, and spindle shapes were seen circulating through the capillaries and sinusoids of the tissues, principally of the hematopoietic organs. Stasis occurs because the diameter of the circulating parasites is greater than the vessels, and this makes them more visible. Examination of the sternal bone marrow revealed young cells with elongated forms and others truncated in the shape of a "C" occupying the internal surface of the blood cells that had empty central portions (erythrocytes?. We hypothesize that there could be a loss of virulence or mutation of the Y strain of Trypanosoma cruzi.

  5. In vivo studies of 5-arylethenylbenzofuroxans in acute murine models of Chagas' disease.

    Science.gov (United States)

    Boiani, Lucía; Davies, Carolina; Arredondo, Carolina; Porcal, Williams; Merlino, Alicia; Gerpe, Alejandra; Boiani, Mariana; Pacheco, José Pedro; Basombrío, Miguel Angel; Cerecetto, Hugo; González, Mercedes

    2008-10-01

    5-arylethenylbenzofuroxan derivatives with high in vitro anti-Trypanosoma cruzi activity were studied in vivo using acute murine models of Chagas' disease. The selected compounds, as pure isomeric forms, 1, 2, 3 and 4, or as equimolecular mixture of geometric isomers, 1:2, 3:4, 5:6 were studied against different T. cruzi strains. Consequently, Tulahuen 2 strain, Colombiana strain (resistant to Nifurtimox and Benznidazole), and two different wild strains, one isolated from the wild reservoir Didelphis marsupialis and another one from Uruguayan patients, were selected. No relevant signs of in vivo toxicity were observed with the benzofuroxans orally administered. Compound 1 and the mixture of isomers 1:2 were the best for treating infection against the four studied strains. PMID:18255195

  6. Structure-based approach to the identification of a novel group of selective glucosamine analogue inhibitors of Trypanosoma cruzi glucokinase.

    Science.gov (United States)

    D'Antonio, Edward L; Deinema, Mason S; Kearns, Sean P; Frey, Tyler A; Tanghe, Scott; Perry, Kay; Roy, Timothy A; Gracz, Hanna S; Rodriguez, Ana; D'Antonio, Jennifer

    2015-12-01

    Glucokinase and hexokinase from pathogenic protozoa Trypanosoma cruzi are potential drug targets for antiparasitic chemotherapy of Chagas' disease. These glucose kinases phosphorylate d-glucose with co-substrate ATP and yield glucose 6-phosphate and are involved in essential metabolic pathways, such as glycolysis and the pentose phosphate pathway. An inhibitor class was conceived that is selective for T. cruzi glucokinase (TcGlcK) using structure-based drug design involving glucosamine having a linker from the C2 amino that terminates with a hydrophobic group either being phenyl, p-hydroxyphenyl, or dioxobenzo[b]thiophenyl groups. The synthesis and characterization for two of the four compounds are presented while the other two compounds were commercially available. Four high-resolution X-ray crystal structures of TcGlcK inhibitor complexes are reported along with enzyme inhibition constants (Ki) for TcGlcK and Homo sapiens hexokinase IV (HsHxKIV). These glucosamine analogue inhibitors include three strongly selective TcGlcK inhibitors and a fourth inhibitor, benzoyl glucosamine (BENZ-GlcN), which is a similar variant exhibiting a shorter linker. Carboxybenzyl glucosamine (CBZ-GlcN) was found to be the strongest glucokinase inhibitor known to date, having a Ki of 0.71±0.05μM. Also reported are two biologically active inhibitors against in vitro T. cruzi culture that were BENZ-GlcN and CBZ-GlcN, with intracellular amastigote growth inhibition IC50 values of 16.08±0.16μM and 48.73±0.69μM, respectively. These compounds revealed little to no toxicity against mammalian NIH-3T3 fibroblasts and provide a key starting point for further drug development with this class of compound. PMID:26778112

  7. Trypanosoma cruzi adjuvants potentiate T cell-mediated immunity induced by a NY-ESO-1 based antitumor vaccine.

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    Caroline Junqueira

    Full Text Available Immunological adjuvants that induce T cell-mediate immunity (TCMI with the least side effects are needed for the development of human vaccines. Glycoinositolphospholipids (GIPL and CpGs oligodeoxynucleotides (CpG ODNs derived from the protozoa parasite Trypanosoma cruzi induce potent pro-inflammatory reaction through activation of Toll-Like Receptor (TLR4 and TLR9, respectively. Here, using mouse models, we tested the T. cruzi derived TLR agonists as immunological adjuvants in an antitumor vaccine. For comparison, we used well-established TLR agonists, such as the bacterial derived monophosphoryl lipid A (MPL, lipopeptide (Pam3Cys, and CpG ODN. All tested TLR agonists were comparable to induce antibody responses, whereas significant differences were noticed in their ability to elicit CD4(+ T and CD8(+ T cell responses. In particular, both GIPLs (GTH, and GY and CpG ODNs (B344, B297 and B128 derived from T. cruzi elicited interferon-gamma (IFN-γ production by CD4(+ T cells. On the other hand, the parasite derived CpG ODNs, but not GIPLs, elicited a potent IFN-γ response by CD8(+ T lymphocytes. The side effects were also evaluated by local pain (hypernociception. The intensity of hypernociception induced by vaccination was alleviated by administration of an analgesic drug without affecting protective immunity. Finally, the level of protective immunity against the NY-ESO-1 expressing melanoma was associated with the magnitude of both CD4(+ T and CD8(+ T cell responses elicited by a specific immunological adjuvant.

  8. Trypanosoma cruzi adjuvants potentiate T cell-mediated immunity induced by a NY-ESO-1 based antitumor vaccine.

    Science.gov (United States)

    Junqueira, Caroline; Guerrero, Ana Tereza; Galvão-Filho, Bruno; Andrade, Warrison A; Salgado, Ana Paula C; Cunha, Thiago M; Ropert, Catherine; Campos, Marco Antônio; Penido, Marcus L O; Mendonça-Previato, Lúcia; Previato, José Oswaldo; Ritter, Gerd; Cunha, Fernando Q; Gazzinelli, Ricardo T

    2012-01-01

    Immunological adjuvants that induce T cell-mediate immunity (TCMI) with the least side effects are needed for the development of human vaccines. Glycoinositolphospholipids (GIPL) and CpGs oligodeoxynucleotides (CpG ODNs) derived from the protozoa parasite Trypanosoma cruzi induce potent pro-inflammatory reaction through activation of Toll-Like Receptor (TLR)4 and TLR9, respectively. Here, using mouse models, we tested the T. cruzi derived TLR agonists as immunological adjuvants in an antitumor vaccine. For comparison, we used well-established TLR agonists, such as the bacterial derived monophosphoryl lipid A (MPL), lipopeptide (Pam3Cys), and CpG ODN. All tested TLR agonists were comparable to induce antibody responses, whereas significant differences were noticed in their ability to elicit CD4(+) T and CD8(+) T cell responses. In particular, both GIPLs (GTH, and GY) and CpG ODNs (B344, B297 and B128) derived from T. cruzi elicited interferon-gamma (IFN-γ) production by CD4(+) T cells. On the other hand, the parasite derived CpG ODNs, but not GIPLs, elicited a potent IFN-γ response by CD8(+) T lymphocytes. The side effects were also evaluated by local pain (hypernociception). The intensity of hypernociception induced by vaccination was alleviated by administration of an analgesic drug without affecting protective immunity. Finally, the level of protective immunity against the NY-ESO-1 expressing melanoma was associated with the magnitude of both CD4(+) T and CD8(+) T cell responses elicited by a specific immunological adjuvant.

  9. Immunocytochemical identification of leishmania and Trypanosoma cruzi amastigotes in situ with homologous and heterologous polyclonal antibodies

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    A.J.A. Barbosa

    1991-03-01

    Full Text Available The unlabelled antibody peroxidase-antiperoxidase method was used to study the immunocytochemical properties of Leishmania and Trypanosoma cruzi amastigotes in situ after tissues had been submitted to different fixation procedures. Antisera were obtained from rabbits chronically infected with different strains of T. cruzi or immunized with L. mexicana amazonensis and L. braziliensis guyanensis, and were applied on 5 µm thick sections. T. cruzi antigens were well stained by the three anti-T. cruzi sera and the two anti-heis.hmama.sera at optimum dilution between 1:1,000 and 1:2,000, regardless the parasite strain. Differently, the leishmanial antigens were revealed by Leishmania sera only at low dilutions (between 1:60 -1:160, whereas the anti-T. cruzi sera, at these low dilutions, gave rather weak stainings. Although there is no clear explanation for this immunocytochemical "reverse-monodirectional" cross-reactivity between Leishmania and T. cruzi, the present results show that polyclonal antibodies agains Leishmania species, when used for immunocytochemical detection of these parasites in situ, react more strongly with T. cruzi amastigotes than with the homologous amastigotes.

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

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    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

  11. Specific Endocytosis Blockade of Trypanosoma cruzi Exposed to a Poly-LAcNAc Binding Lectin Suggests that Lectin-Sugar Interactions Participate to Receptor-Mediated Endocytosis

    Science.gov (United States)

    Brosson, Sébastien; Fontaine, Frédéric; Vermeersch, Marjorie; Perez-Morga, David; Pays, Etienne; Bousbata, Sabrina; Salmon, Didier

    2016-01-01

    Trypanosoma cruzi is a protozoan parasite transmitted by a triatomine insect, and causing human Chagas disease in South America. This parasite undergoes a complex life cycle alternating between non-proliferative and dividing forms. Owing to their high energy requirement, replicative epimastigotes of the insect midgut display high endocytic activity. This activity is mainly restricted to the cytostome, by which the cargo is taken up and sorted through the endosomal vesicular network to be delivered to reservosomes, the final lysosomal-like compartments. In African trypanosomes tomato lectin (TL) and ricin, respectively specific to poly-N-acetyllactosamine (poly-LacNAc) and β-D-galactose, allowed the identification of giant chains of poly-LacNAc in N-glycoproteins of the endocytic pathway. We show that in T. cruzi epimastigote forms also, glycoproteins of the endocytic pathway are characterized by the presence of N-linked glycans binding to both ricin and TL. Affinity chromatography using both TL and Griffonia simplicifolia lectin II (GSLII), specific to non-reducing terminal residue of N-acetylglucosamine (GlcNAc), led to an enrichment of glycoproteins of the trypanosomal endocytic pathway. Incubation of live parasites with TL, which selectively bound to the cytostome/cytopharynx, specifically inhibited endocytosis of transferrin (Tf) but not dextran, a marker of fluid endocytosis. Taken together, our data suggest that N-glycan modification of endocytic components plays a crucial role in receptor-mediated endocytosis of T. cruzi. PMID:27685262

  12. Trypanosoma cruzi trans-sialidase in complex with a neutralizing antibody: structure/function studies towards the rational design of inhibitors.

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    Alejandro Buschiazzo

    2012-01-01

    Full Text Available Trans-sialidase (TS, a virulence factor from Trypanosoma cruzi, is an enzyme playing key roles in the biology of this protozoan parasite. Absent from the mammalian host, it constitutes a potential target for the development of novel chemotherapeutic drugs, an urgent need to combat Chagas' disease. TS is involved in host cell invasion and parasite survival in the bloodstream. However, TS is also actively shed by the parasite to the bloodstream, inducing systemic effects readily detected during the acute phase of the disease, in particular, hematological alterations and triggering of immune cells apoptosis, until specific neutralizing antibodies are elicited. These antibodies constitute the only known submicromolar inhibitor of TS's catalytic activity. We now report the identification and detailed characterization of a neutralizing mouse monoclonal antibody (mAb 13G9, recognizing T. cruzi TS with high specificity and subnanomolar affinity. This mAb displays undetectable association with the T. cruzi superfamily of TS-like proteins or yet with the TS-related enzymes from Trypanosoma brucei or Trypanosoma rangeli. In immunofluorescence assays, mAb 13G9 labeled 100% of the parasites from the infective trypomastigote stage. This mAb also reduces parasite invasion of cultured cells and strongly inhibits parasite surface sialylation. The crystal structure of the mAb 13G9 antigen-binding fragment in complex with the globular region of T. cruzi TS was determined, revealing detailed molecular insights of the inhibition mechanism. Not occluding the enzyme's catalytic site, the antibody performs a subtle action by inhibiting the movement of an assisting tyrosine (Y₁₁₉, whose mobility is known to play a key role in the trans-glycosidase mechanism. As an example of enzymatic inhibition involving non-catalytic residues that occupy sites distal from the substrate-binding pocket, this first near atomic characterization of a high affinity inhibitory molecule

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

    Science.gov (United States)

    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

  14. Novo processo para triagem de medicamentos na infecção experimental pelo Trypanosoma cruzi Proposal of a new process for screening of drugs in experimental infection with Trypanosoma cruzi

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    Rubens Campos

    1991-08-01

    Full Text Available É proposto processo para a triagem da capacidade terapêutica de medicamentos na infecção experimental pelo Trypanosoma cruzi. O método tem base no emprego de triatomíneos parasitados que se alimentam, decorridos períodos diferentes para haver compatibilização com níveis sangüíneos, em camundongos aos quais foi administrado o fármaco sob apreciação; assim, o tubo digestivo do hemíptero participará como estrutura propícia à avaliação. Em observação inicial, ocorreu utilização do benzonidazol, que se mostrou apenas parcialmente ativo, pelo menos de acordo com a maneira de execução do novo procedimento.We propose a screening process for detection of therapeutic activity of drugs against experimental infection with Trypanosoma cruzi. It is based on the use of infected tryatominae that are fed on mice which have received the study drug. Blood meals are made at different time schedule in order to adapt with serum drug levels. The digestive tube of the hemyptera will, thus, work as a suitable structure for examination. In a initial observation, benzonidazole was used, and was shown to be only partially active at least in the conditions of this new procedure.

  15. In vitro cytocidal effect of novel lytic peptides on Plasmodium falciparum and Trypanosoma cruzi.

    Science.gov (United States)

    Jaynes, J M; Burton, C A; Barr, S B; Jeffers, G W; Julian, G R; White, K L; Enright, F M; Klei, T R; Laine, R A

    1988-10-01

    Plasmodium falciparum and Trypanosoma cruzi were killed by two novel lytic peptides (SB-37 and Shiva-1) in vitro. Human erythrocytes infected with P. falciparum, and Vero cells infected with T. cruzi, were exposed to these peptides. The result, in both cases, was a significant decrease in the level of parasite infection. Furthermore, the peptides had a marked cytocidal effect on trypomastigote stages of T. cruzi in media, whereas host eukaryotic cells were unaffected by the treatments. In view of the worldwide prevalence of these protozoan diseases and the lack of completely suitable treatments, lytic peptides may provide new and unique chemotherapeutic agents for the treatment of these infections.

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

    Science.gov (United States)

    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.

  17. In vitro effects of citral on Trypanosoma cruzi metacyclogenesis

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    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.

  18. Experimental infections in Venezuelan lizards by Trypanosoma cruzi.

    Science.gov (United States)

    Urdaneta-Morales, S; McLure, I

    1981-06-01

    Virulent trypomastigotes of the Y strain of Trypanosoma cruzi were administered to Tropidurus hispidus, Ameiva ameiva, Cnemidophorus lemniscatus, Polychrus marmoratus, and Phyllodactylus ventralis (Sauria). Intraperitoneal and subcutaneous inoculations of lizards with mouse blood or with feces of infected Rhodnius prolixus (Reduviidae, Triatominae), as well as forced ingestion of triturated Rhodnius, produced no parasitaemias detectable either directly or by xenodiagnosis, while control mice became parasitized. Pretreatment with the immunosuppressive drug Fluocinolone acetonide led to establishing patent infections in inoculated lizards. Cryptic infections were established by inoculation of 1 X 10(6) parasites from Davis' medium, or by 95 X 10(3) parasites from lizard tissue culture. Parasites were not seen in tissues. Mice inoculated with blood or tissue homogenates from these lizards became parasitized. Parasites from Davis' medium inoculated into the peritoneal cavity of lizards were capable, to a very low degree, of penetrating the free peritoneal macrophages and changing into amastigotes. The factors possibly responsible for the natural resistance of poikilothermic vertebrates to T. cruzi are discussed. PMID:6115559

  19. Monocytes play an IL-12-dependent crucial role in driving cord blood NK cells to produce IFN-g in response to Trypanosoma cruzi.

    Science.gov (United States)

    Guilmot, Aline; Bosse, Julie; Carlier, Yves; Truyens, Carine

    2013-01-01

    We previously reported that foetuses congenitally infected with Trypanosoma cruzi, the agent of Chagas disease, mount an adult-like parasite-specific CD8(+) T-cell response, producing IFN-g, and present an altered NK cell phenotype, possibly reflecting a post-activation state supported by the ability of the parasite to trigger IFN-g synthesis by NK cells in vitro. We here extended our knowledge on NK cell activation by the parasite. We compared the ability of T. cruzi to activate cord blood and adult NK cells from healthy individuals. Twenty-four hours co-culture of cord blood mononuclear cells with T. cruzi trypomastigotes and IL-15 induced high accumulation of IFN-g transcripts and IFN-g release. TNF-a, but not IL-10, was also produced. This was associated with up-regulation of CD69 and CD54, and down-regulation of CD62L on NK cells. The CD56(bright) NK cell subset was the major IFN-g responding subset (up to 70% IFN-g-positive cells), while CD56(dim) NK cells produced IFN-g to a lesser extent. The response points to a synergy between parasites and IL-15. The neonatal response, observed in all newborns, remained however slightly inferior to that of adults. Activation of IL-15-sensitized cord blood NK cells by the parasite required contacts with live/intact parasites. In addition, it depended on the engagement of TLR-2 and 4 and involved IL-12 and cross-talk with monocytes but not with myeloid dendritic cells, as shown by the use of neutralizing antibodies and cell depletion. This work highlights the ability of T. cruzi to trigger a robust IFN-g response by IL-15-sensitized human neonatal NK cells and the important role of monocytes in it, which might perhaps partially compensate for the neonatal defects of DCs. It suggests that monocyte- and IL-12- dependent IFN-g release by NK cells is a potentially important innate immune response pathway allowing T. cruzi to favour a type 1 immune response in neonates.

  20. Monocytes play an IL-12-dependent crucial role in driving cord blood NK cells to produce IFN-g in response to Trypanosoma cruzi.

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    Aline Guilmot

    Full Text Available We previously reported that foetuses congenitally infected with Trypanosoma cruzi, the agent of Chagas disease, mount an adult-like parasite-specific CD8(+ T-cell response, producing IFN-g, and present an altered NK cell phenotype, possibly reflecting a post-activation state supported by the ability of the parasite to trigger IFN-g synthesis by NK cells in vitro. We here extended our knowledge on NK cell activation by the parasite. We compared the ability of T. cruzi to activate cord blood and adult NK cells from healthy individuals. Twenty-four hours co-culture of cord blood mononuclear cells with T. cruzi trypomastigotes and IL-15 induced high accumulation of IFN-g transcripts and IFN-g release. TNF-a, but not IL-10, was also produced. This was associated with up-regulation of CD69 and CD54, and down-regulation of CD62L on NK cells. The CD56(bright NK cell subset was the major IFN-g responding subset (up to 70% IFN-g-positive cells, while CD56(dim NK cells produced IFN-g to a lesser extent. The response points to a synergy between parasites and IL-15. The neonatal response, observed in all newborns, remained however slightly inferior to that of adults. Activation of IL-15-sensitized cord blood NK cells by the parasite required contacts with live/intact parasites. In addition, it depended on the engagement of TLR-2 and 4 and involved IL-12 and cross-talk with monocytes but not with myeloid dendritic cells, as shown by the use of neutralizing antibodies and cell depletion. This work highlights the ability of T. cruzi to trigger a robust IFN-g response by IL-15-sensitized human neonatal NK cells and the important role of monocytes in it, which might perhaps partially compensate for the neonatal defects of DCs. It suggests that monocyte- and IL-12- dependent IFN-g release by NK cells is a potentially important innate immune response pathway allowing T. cruzi to favour a type 1 immune response in neonates.

  1. Structural basis for rational design of inhibitors targeting Trypanosoma cruzi sterol 14α-demethylase: two regions of the enzyme molecule potentiate its inhibition.

    Science.gov (United States)

    Friggeri, Laura; Hargrove, Tatiana Y; Rachakonda, Girish; Williams, Amanda D; Wawrzak, Zdzislaw; Di Santo, Roberto; De Vita, Daniela; Waterman, Michael R; Tortorella, Silvano; Villalta, Fernando; Lepesheva, Galina I

    2014-08-14

    Chagas disease, which was once thought to be confined to endemic regions of Latin America, has now gone global, becoming a new worldwide challenge with no cure available. The disease is caused by the protozoan parasite Trypanosoma cruzi, which depends on the production of endogenous sterols, and therefore can be blocked by sterol 14α-demethylase (CYP51) inhibitors. Here we explore the spectral binding parameters, inhibitory effects on T. cruzi CYP51 activity, and antiparasitic potencies of a new set of β-phenyl imidazoles. Comparative structural characterization of the T. cruzi CYP51 complexes with the three most potent inhibitors reveals two opposite binding modes of the compounds ((R)-6, EC50=1.2 nM, vs (S)-2/(S)-3, EC50=1.0/5.5 nM) and suggests the entrance into the CYP51 substrate access channel and the heme propionate-supporting ceiling of the binding cavity as two distinct areas of the protein that enhance molecular recognition and therefore could be used for the development of more effective antiparasitic drugs. PMID:25033013

  2. Morphological aspects of the myocarditis and myositis in Calomys callosus experimentally infected with Trypanosoma cruzi: fibrogenesis and spontaneous regression of fibrosis

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    Sonia G. Andrade

    1994-09-01

    Full Text Available Calomys callosus a wild rodent, is a natural host of Trypanosoma cruzi. Twelve C. callosus were infected with 10(5 trypomastigotes of the F strain (a myotropic strain of T. cruzi. Parasitemia decreased on the 21 st day becoming negative around the 40th day of infection. All animals survived but had positive parasitological tests, until the end of the experiment. The infected animals developed severe inflammation in the myocardium and skeletal muscle. This process was pronounced from the 26 th to the 30th day and gradually subsided from the 50 th day becoming absent or residual on the 64 th day after infection. Collagen was identified by the picro Sirius red method. Fibrogenesis developed early, but regression of fibrosis occurred between the 50th and 64th day. Ultrastructural study disclosed a predominance of macrophages and fibroblasts in the inflammatory infiltrates, with small numbers of lymphocytes. Macrophages had active phagocytosis and showed points of contact with altered muscle cells. Different degrees of matrix expansion were present, with granular and fibrilar deposits and collagen bundles. These alterations subsided by the 64th days. Macrophages seem to be the main immune effector cell in the C. callosus model of infection with T. cruzi. The mechanisms involved in the rapid fibrogenesis and its regression deserve further investigation.

  3. Criopreservação de formas de cultura do Trypanosoma cruzi Cryopreservation of Trypanosoma cruzi culture form

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    Lúcia Maria C. Galvão

    1981-09-01

    Full Text Available Formas de cultura de diferentes cepas do T.cruzi foram submetidas a vários processos de criopreservação. As percentagens de recuperação, avaliadas pela motilidade dos parasitas, foram consideradas como adequadas com algumas das técnicas empregadas, variando entre 60 a 80%. A estabilidade das características biológicas do material criopreservado foi investigada através do estudo das curvas de crescimento e diferenciação em meio acelular, infectividade para celulas de cultura de tecido ("Vero", diferenciação intracelular em cultura de tecido assim como infectividade e curso da infecção em animais de laboratório. De um modo geral essas características nao foram significativamente alteradas no material congelado e estocado por diferentes períodos de tempo.A systematic study of the cryopreservation of T. cruzi culture forms was per formed using different parasite strains and freezing methods. The recovery rates with some of the methods as evaluated by motility of the thawed parasites were fairly high (60-80%. The following aspects have been used to investigate the stability of the parasites' biological characteristics atter cryopreservation: growth and differentiation in acelular medium, infectivity to tissue culture "Vero" cells, intracellular differentiation and infectivity to animals. Those characteristics had not been significantly changed by the cryopreservation procedures.

  4. An Investigation on the Ecology of Triatoma vitticeps (Stal, 1859 and its Possible Role in the Transmission of Trypanosoma cruzi, in the Locality of Triunfo, Santa Maria Madalena Municipal District, State of Rio de Janeiro, Brazil

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    Gonçalves Teresa Cristina M

    1998-01-01

    Full Text Available From January 1989 to April 1995, 465 specimens of Triatoma vitticeps were collected in the locality of Triunfo, 2nd District of Santa Maria Madalena municipal district, State of Rio de Janeiro. The bugs were found indoors by local residents with predominance of adults. The flight activity was high in hot months when the incidence in the domicile also increased. Two hundred and two bugs (111 alive and 91 dead were examined for Trypanosoma cruzi infection. This was detected in 31 of the dead bugs (34% and 88 (79% of the live bugs examined. With a view to investigate the possible vertebrate hosts of the T. cruzi isolates, the blood of 122 mammals was examined through Giemsa-stained smears, hemocultures and xenodiagnosis. T. cruzi was detected in three specimens of Didelphis marsupialis and T. (M. theileri was detected in one specimen of Bos taurus. The parasites were isolated from triatomine feces, xenoculture and hemoculture. No evidence of human infection was detected in 58 inhabitants examined, as evaluated by indirect imunofluorescence technique using T. cruzi epimastigotes as antigens. These results show that T. vitticeps is still a sylvatic species although nymphs have been found inside the domicile. Thus, an epidemiological vigilance is necessary to know the behaviour of this species following the continuous modifications promoted by the presence of man.

  5. An investigation on the ecology of Triatoma vitticeps (Stal, 1859) and its possible role in the transmission of Trypanosoma cruzi, in the locality of Triunfo, Santa Maria Madalena municipal district, state of Rio de Janeiro, Brazil.

    Science.gov (United States)

    Gonçalves, T C; de Oliveira, E; Dias, L S; Almeida, M D; Nogueira, W O; Pires, F D

    1998-01-01

    From January 1989 to April 1995, 465 specimens of Triatoma vitticeps were collected in the locality of Triunfo, 2nd District of Santa Maria Madalena municipal district, State of Rio de Janeiro. The bugs were found indoors by local residents with predominance of adults. The flight activity was high in hot months when the incidence in the domicile also increased. Two hundred and two bugs (111 alive and 91 dead) were examined for Trypanosoma cruzi infection. This was detected in 31 of the dead bugs (34%) and 88 (79%) of the live bugs examined. With a view to investigate the possible vertebrate hosts of the T. cruzi isolates, the blood of 122 mammals was examined through Giemsa-stained smears, hemocultures and xenodiagnosis. T. cruzi was detected in three specimens of Didelphis marsupialis and T. (M.) theileri was detected in one specimen of Bos taurus. The parasites were isolated from triatomine feces, xenoculture and hemoculture. No evidence of human infection was detected in 58 inhabitants examined, as evaluated by indirect imunofluorescence technique using T. cruzi epimastigotes as antigens. These results show that T. vitticeps is still a sylvatic species although nymphs have been found inside the domicile. Thus, an epidemiological vigilance is necessary to know the behaviour of this species following the continuous modifications promoted by the presence of man. PMID:9921289

  6. Experimental Chemotherapy for Chagas Disease: A Morphological, Biochemical, and Proteomic Overview of Potential Trypanosoma cruzi Targets of Amidines Derivatives and Naphthoquinones.

    Science.gov (United States)

    de Castro, Solange L; Batista, Denise G J; Batista, Marcos M; Batista, Wanderson; Daliry, Anissa; de Souza, Elen M; Menna-Barreto, Rubem F S; Oliveira, Gabriel M; Salomão, Kelly; Silva, Cristiane F; Silva, Patricia B; Soeiro, Maria de Nazaré C

    2011-01-01

    Chagas disease (CD), caused by Trypanosoma cruzi, affects approximately eight million individuals in Latin America and is emerging in nonendemic areas due to the globalisation of immigration and nonvectorial transmission routes. Although CD represents an important public health problem, resulting in high morbidity and considerable mortality rates, few investments have been allocated towards developing novel anti-T. cruzi agents. The available therapy for CD is based on two nitro derivatives (benznidazole (Bz) and nifurtimox (Nf)) developed more than four decades ago. Both are far from ideal due to substantial secondary side effects, limited efficacy against different parasite isolates, long-term therapy, and their well-known poor activity in the late chronic phase. These drawbacks justify the urgent need to identify better drugs to treat chagasic patients. Although several classes of natural and synthetic compounds have been reported to act in vitro and in vivo on T. cruzi, since the introduction of Bz and Nf, only a few drugs, such as allopurinol and a few sterol inhibitors, have moved to clinical trials. This reflects, at least in part, the absence of well-established universal protocols to screen and compare drug activity. In addition, a large number of in vitro studies have been conducted using only epimastigotes and trypomastigotes instead of evaluating compounds' activities against intracellular amastigotes, which are the reproductive forms in the vertebrate host and are thus an important determinant in the selection and identification of effective compounds for further in vivo analysis. In addition, due to pharmacokinetics and absorption, distribution, metabolism, and excretion characteristics, several compounds that were promising in vitro have not been as effective as Nf or Bz in animal models of T. cruzi infection. In the last two decades, our team has collaborated with different medicinal chemistry groups to develop preclinical studies for CD and

  7. Experimental Chemotherapy for Chagas Disease: A Morphological, Biochemical, and Proteomic Overview of Potential Trypanosoma cruzi Targets of Amidines Derivatives and Naphthoquinones

    Directory of Open Access Journals (Sweden)

    Solange L. de Castro

    2011-01-01

    Full Text Available Chagas disease (CD, caused by Trypanosoma cruzi, affects approximately eight million individuals in Latin America and is emerging in nonendemic areas due to the globalisation of immigration and nonvectorial transmission routes. Although CD represents an important public health problem, resulting in high morbidity and considerable mortality rates, few investments have been allocated towards developing novel anti-T. cruzi agents. The available therapy for CD is based on two nitro derivatives (benznidazole (Bz and nifurtimox (Nf developed more than four decades ago. Both are far from ideal due to substantial secondary side effects, limited efficacy against different parasite isolates, long-term therapy, and their well-known poor activity in the late chronic phase. These drawbacks justify the urgent need to identify better drugs to treat chagasic patients. Although several classes of natural and synthetic compounds have been reported to act in vitro and in vivo on T. cruzi, since the introduction of Bz and Nf, only a few drugs, such as allopurinol and a few sterol inhibitors, have moved to clinical trials. This reflects, at least in part, the absence of well-established universal protocols to screen and compare drug activity. In addition, a large number of in vitro studies have been conducted using only epimastigotes and trypomastigotes instead of evaluating compounds' activities against intracellular amastigotes, which are the reproductive forms in the vertebrate host and are thus an important determinant in the selection and identification of effective compounds for further in vivo analysis. In addition, due to pharmacokinetics and absorption, distribution, metabolism, and excretion characteristics, several compounds that were promising in vitro have not been as effective as Nf or Bz in animal models of T. cruzi infection. In the last two decades, our team has collaborated with different medicinal chemistry groups to develop preclinical studies

  8. Genetic diversity of Colombian sylvatic Trypanosoma cruzi isolates revealed by the ribosomal DNA

    Directory of Open Access Journals (Sweden)

    Cuervo Patricia

    2002-01-01

    Full Text Available American trypanosomiasis is a common zoonosis in Colombia and Trypanosoma cruzi presents a wide distribution throughout the country. Although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using Colombian strains. In this study, we amplified the non-transcribed spacer of the mini-gene by PCR, typing the isolates as T. cruzi I, T. cruzi zymodeme 3 or T. rangeli. In addition, the internal transcribed spacers of the ribosomal gene concomitant with the 5.8S rDNA were amplified and submitted to restriction fragment polymorphism analysis. The profiles were analyzed by a numerical methodology generating a phenetic dendrogram that shows heterogeneity among the T. cruzi isolates. This finding suggests a relationship between the complexity of the sylvatic transmission cycle in Colombia and the diversity of the sylvan parasites.

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

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    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.

  10. The Role of Heme and Reactive Oxygen Species in Proliferation and Survival of Trypanosoma cruzi

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    Marcia Cristina Paes

    2011-01-01

    Full Text Available Trypanosoma cruzi, the protozoan responsible for Chagas disease, has a complex life cycle comprehending two distinct hosts and a series of morphological and functional transformations. Hemoglobin degradation inside the insect vector releases high amounts of heme, and this molecule is known to exert a number of physiological functions. Moreover, the absence of its complete biosynthetic pathway in T. cruzi indicates heme as an essential molecule for this trypanosomatid survival. Within the hosts, T. cruzi has to cope with sudden environmental changes especially in the redox status and heme is able to increase the basal production of reactive oxygen species (ROS which can be also produced as byproducts of the parasite aerobic metabolism. In this regard, ROS sensing is likely to be an important mechanism for the adaptation and interaction of these organisms with their hosts. In this paper we discuss the main features of heme and ROS susceptibility in T. cruzi biology.

  11. CC-chemokine receptors: a potential therapeutic target for Trypanosoma cruzi-elicited myocarditis.

    Science.gov (United States)

    Marino, A P M P; Silva, A A; Santos, P V A; Pinto, L M O; Gazinelli, R T; Teixeira, M M; Lannes-Vieira, J

    2005-03-01

    The comprehension of the pathogenesis of Trypanosoma cruzi-elicited myocarditis is crucial to delineate new therapeutic strategies aiming to ameliorate the inflammation that leads to heart dysfunction, without hampering parasite control. The augmented expression of CCL5/RANTES and CCL3/MIP-1alpha, and their receptor CCR5, in the heart of T. cruzi-infected mice suggests a role for CC-chemokines and their receptors in the pathogenesis of T. cruzi-elicited myocarditis. Herein, we discuss our recent results using a CC-chemokine receptor inhibitor (Met-RANTES), showing the participation of CC-chemokines in T. cruzi infection and unraveling CC-chemokine receptors as an attractive therapeutic target for further evaluation in Chagas disease.

  12. CC-chemokine receptors: a potential therapeutic target for Trypanosoma cruzi-elicited myocarditis

    Directory of Open Access Journals (Sweden)

    APMP Marino

    2005-03-01

    Full Text Available The comprehension of the pathogenesis of Trypanosoma cruzi-elicited myocarditis is crucial to delineate new therapeutic strategies aiming to ameliorate the inflammation that leads to heart dysfunction, without hampering parasite control. The augmented expression of CCL5/RANTES and CCL3/MIP-1alpha, and their receptor CCR5, in the heart of T. cruzi-infected mice suggests a role for CC-chemokines and their receptors in the pathogenesis of T. cruzi-elicited myocarditis. Herein, we discuss our recent results using a CC-chemokine receptor inhibitor (Met-RANTES, showing the participation of CC-chemokines in T. cruzi infection and unraveling CC-chemokine receptors as an attractive therapeutic target for further evaluation in Chagas disease.

  13. ESTUDIO SEROLOGICO POR INMUNOFLUORESCENCIA DE LA ENFERMEDAD DE CHAGAS EN COSTA RICA

    OpenAIRE

    LILIANA REYES; Bonilla, A.; T. MOYA; MISAEL CHINCHILLA

    1998-01-01

    RESUMEN Se estudiaron 1.043 sueros de pacientes provenientes de todo el territorio nacional por anticuerpos anti-Trypanosoma cruzi utilizando la técnica de inmunofluorescencia. Se demostró un porcentaje de positividad general de 2,14%. La mayor positividad se encontró en la provincia de San José (2,4%) y la menor en Heredia (0,8%).SEROLOGICAL STUDY OF CHAGAS DISEASE IN COSTA RICA BY IMMUNOFLUORESCENCE One thousand and fourty three patients were studied for anti-Trypanosoma cruzi antibodies by...

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

    OpenAIRE

    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 (...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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.

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

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    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

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

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    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.

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    OpenAIRE

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

    OpenAIRE

    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...

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

    OpenAIRE

    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. Isolation and Identification of 9-methylgermacrene-B as the Putative Sex Pheromone of Lutzomyia cruzi (Mangabeira, 1938 (Diptera: Psychodidae

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    Brazil Reginaldo P

    2002-01-01

    Full Text Available Lutzomyia (Lutzomyia cruzi has been named as a probable vector of Leishmania chagasi in Corumbá, Mato Grosso do Sul, Brazil. Taxonomically L. cruzi is closely related to the L. longipalpis species complex. Females of L. cruzi and L. longipalpis are morphologically indistinguishable and associated males must be examined carefully to confirm identifications. Chemical analysis hexane extracts of male L. cruzi has revealed the presence of a 9-methylgermacrene-B (C16, a homosesquiterpene (mw 218 previously shown to be the sex pheromone of one of the members of the L. longipalpis species complex.

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

    Science.gov (United States)

    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

  12. Immunocytochemical identification of leishmania and Trypanosoma cruzi amastigotes in situ with homologous and heterologous polyclonal antibodies

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    A.J.A. Barbosa

    1991-03-01

    Full Text Available The unlabelled antibody peroxidase-antiperoxidase method was used to study the immunocytochemical properties of Leishmania and Trypanosoma cruzi amastigotes in situ after tissues had been submitted to different fixation procedures. Antisera were obtained from rabbits chronically infected with different strains of T. cruzi or immunized with L. mexicana amazonensis and L. braziliensis guyanensis, and were applied on 5 µm thick sections. T. cruzi antigens were well stained by the three anti-T. cruzi sera and the two anti-heis.hmama.sera at optimum dilution between 1:1,000 and 1:2,000, regardless the parasite strain. Differently, the leishmanial antigens were revealed by Leishmania sera only at low dilutions (between 1:60 -1:160, whereas the anti-T. cruzi sera, at these low dilutions, gave rather weak stainings. Although there is no clear explanation for this immunocytochemical "reverse-monodirectional" cross-reactivity between Leishmania and T. cruzi, the present results show that polyclonal antibodies agains Leishmania species, when used for immunocytochemical detection of these parasites in situ, react more strongly with T. cruzi amastigotes than with the homologous amastigotes.O método daperoxidase-antiperoxidase foi utilizado para estudar as propriedades imunocitoquimicas de Leishmanias e de amastigotas do Trypanosoma cruzi, in situ, após os tecidos terem sido submetidos a diferentes tipos de fixação. Anti-soros foram obtidos de coelhos cronicamente infectados com três cepas de T. cruzi ou imunizados com L. mexicana ámazonensis e L. braziliensis guyanensis e aplicados nos cortes histológicos de 5 µm de espessura. Os antígenos de T. cruzi foram corados muito bem pelos três soros anti-T. cruzi e pelos dois soros anti-Leishmania com diluições entre 1:1.000 e 1:2.000. Diferentemente, os antígenos dç Leishmania foram revelados pelos soros anti- Leishmania somente em baixas diluições, ou seja, entre 1:60 e 1:160 enquanto que os soros

  13. Neuronal changes caused by Trypanosoma cruzi: an experimental model

    Directory of Open Access Journals (Sweden)

    Neide M Moreira

    2011-06-01

    Full Text Available Define an experimental model by evaluating quantitative and morphometric changes in myenteric neurons of the colon of mice infected with Trypanosoma cruzi. Twenty-eight Swiss male mice were distributed into groups: control (CG, n=9 and inoculated with 100 (IG100, n=9 and 1000 (IG1000, n=10 blood trypomastigotes, Y strain-T. cruzi II. Parasitemia was evaluated from 3-25 days post inoculation (dpi with parasites peak of 7.7 × 10(6 and 8.4 × 10(6 trypomastigotes/mL at 8th dpi (p>0.05 in IG100 and IG1000, respectively. Chronic phase of the infection was obtained with two doses of 100mg/Kg/weight and one dose of 250mg/Kg/weight of Benznidazole on 11, 16 and 18 dpi. Three animals from each group were euthanized at 18, 30 and 75 dpi. The colon was stained with Giemsa. The quantitative and morphometric analysis of neurons revealed that the infection caused a decrease of neuronal density on 30th dpi (pDefinir um modelo experimental de avaliação de alterações quantitativas e morfométricas nos neurônios mientéricos do cólon de camundongos infectados pelo Trypanosoma cruzi. Vinte e oito camundongos Swiss machos foram distribuídos nos grupos: controle (GC, n=9 e infectados com 100 (IG100, n=9 e 1000 (IG1000, n=10 tripomastigotas sanguíneos, cepa Y-T. cruzi II. A parasitemia foi avaliada 3-25 dias pós inoculação (dpi, com pico de parasitos de 7,7 × 10(6 e 8,4 × 10(6 tripomastigotas/mL no 8º dpi (p>0,05 em IG100 e IG1000, respectivamente. A fase crônica da infecção foi obtida com duas doses de 100mg/Kg/weight e uma dose de 250mg/Kg/ weight do benznidazol, em 11, 16 e 18 dpi. Três animais de cada grupo foram sacrificados aos 18, 30 e 75 dpi. O cólon foi corado com Giemsa. A análise quantitativa e morfométrica de neurônios revelou que a infecção causou uma diminuição da densidade neuronal no 30º dpi (p<0,05 e 75 dpi (p<0,05 em IG100 e IG1000. A infecção causou morte e hipertrofia neuronal no 75º dpi em IG100 e IG1000 (p<0,05, p

  14. Parasite Genome Projects and the Trypanosoma cruzi Genome Initiative

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    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

  15. Proteomic analysis of two Trypanosoma cruzi zymodeme 3 strains.

    Science.gov (United States)

    Kikuchi, Simone A; Sodré, Cátia L; Kalume, Dário E; Elias, Camila G R; Santos, André L S; de Nazaré Soeiro, Maria; Meuser, Marcus; Chapeaurouge, Alex; Perales, Jonas; Fernandes, Octavio

    2010-12-01

    Two Trypanosoma cruzi Z3 strains, designated as 3663 and 4167, were previously isolated from insect vectors captured in the Brazilian Amazon region. These strains exhibited different infection patterns in Vero, C6/36, RAW 264.7 and HEp-2 cell lineages, in which 3663 trypomastigote form was much less infective than 4167 ones. A proteomic approach was applied to investigate the differences in the global patterns of protein expression in these two Z3 strains. Two-dimensional (2D) protein maps were generated and certain spots were identified by mass spectrometry (MS). Our analyses revealed a significant difference in the expression profile of different proteins between strains 3663 and 4167. Among them, cruzipain, an important regulator of infectivity. This data was corroborated by flow cytometry analysis using anti-cruzipain antibody. This difference could contribute to the infectivity profiles observed for each strain by in vitro assay using different cell lines.

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

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    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

  17. Influence of age and ways of treatment in the parasitemia in mice infected with Trypanosoma cruzi treated with high potency biotherapy

    OpenAIRE

    Silvana Marques Araujo; Fabiana Nabarro Ferraz; Camila Fernanda Brustolin; Neide Martins Moreira; Caroline Felicio Braga; Paula Fernanda Massini; Denise Lessa Aleixo

    2011-01-01

    Introduction: The infection of mice by Trypanosoma cruzi is well known, making this a good model for understanding the effect of highly diluted medications. Mice of different ages show different responses to biotherapic T. cruzi [1]. Other data from our laboratory using biotherapic treatment at low potencies show that long lasting treatment has a better effect in mice infected with T. cruzi. However, the use of high potency biotherapics in mice of different ages infected with T. cruzi has not...

  18. Immunocytochemical and biochemical detection of alpha-L-fucosidase in Trypanosoma cruzi

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    Miletti L.C.

    2003-01-01

    Full Text Available The aim of the present study was to demonstrate the presence of alpha-L-fucosidase in Trypanosoma cruzi. Immunocytochemical and biochemical techniques were used to localize and characterize a membrane-associated, neutral-pH-optimum, alpha-L-fucosidase from the parasite. Light and electron microscopy localized the alpha-L-fucosidase specifically on the surface of the parasite and on membranes in the posterior region of the epimastigote stage. Although much less intense, labeling was also detected on the surface of trypomastigotes. At least 50% of the alpha-L-fucosidase activity was associated with epimastigote membrane solubilized with 1 M NaCl or 1% Triton X-100, suggesting that alpha-L-fucosidase is peripherally associated with membranes. The enzyme from epimastigotes had a neutral pH optimum (near 7 but displayed low specific activity when p-nitrophenyl-alpha-L-fucoside was employed as substrate (0.028 U/mg protein for epimastigotes and 0.015 U/mg protein for tissue culture-derived trypomastigotes. Polyacrylamide gel electrophoresis and Western blotting analysis both showed an expected 50-kDa polypeptide which was immunoreactive with anti-alpha-L-fucosidase antibodies.

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

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    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.

  20. Discovery of potent nitrotriazole-based antitrypanosomal agents: In vitro and in vivo evaluation.

    Science.gov (United States)

    Papadopoulou, Maria V; Bloomer, William D; Rosenzweig, Howard S; O'Shea, Ivan P; Wilkinson, Shane R; Kaiser, Marcel; Chatelain, Eric; Ioset, Jean-Robert

    2015-10-01

    3-Nitro-1H-1,2,4-triazole- and 2-nitro-1H-imidazole-based amides with an aryloxy-phenyl core were synthesized and evaluated as antitrypanosomal agents. All 3-nitrotriazole-based derivatives were extremely potent anti-Trypanosoma cruzi agents at sub nM concentrations and exhibited a high degree of selectivity for the parasite. The 2-nitroimidazole analogs were only moderately active against T. cruzi amastigotes and exhibited low selectivity. Both types of compound were active against Leishmania donovani axenic amastigotes with excellent selectivity for the parasite, whereas three 2-nitroimidazole-based analogs were also moderately active against infected macrophages. However, no compound demonstrated selective activity against Trypanosoma brucei rhodesiense. The most potent in vitro anti-T. cruzi compounds were tested in an acute murine model and reduced the parasites to an undetectable level after five days of treatment at 13 mg/kg/day. Such compounds are potential inhibitors of T. cruzi CYP51 and, being excellent substrates for the type I nitroreductase (NTR) which is specific to trypanosomatids, work as prodrugs and constitute a new generation of effective and more affordable antitrypanosomal agents. PMID:26344593

  1. Higher frequency of administration of biotherapic T. cruzi 17DH decreases parasitemia and increases survival in mice infected with Trypanosoma cruzi

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    Áurea Regina Telles Pupulin

    2011-09-01

    Full Text Available Introduction: The study of the effect of different ways of treatment using highly diluted substances is rare in the literature. Some authors consider the dose irrelevant, justifying that the action of the medication highly diluted is qualitative [1-3]. Others emphasize the importance of quantity and frequency of administration of the highly diluted substance for a successful treatment [4,5]. The model of murine infection by T. cruzi is widely studied and it is an excellent tool to study the effect of highly diluted substances. Aim: To evaluate, in vivo, the effect of different amounts and frequency of administration of the biotherapic 17 dH T. cruzi in the evolution of the parasitemia curve and survival of mice infected with Trypanosoma cruzi. Materials and methods: A blind randomised controlled trial was performed, using 30 swiss male mice, aged 28 days, divided into groups according to treatment: CONTROL - mice treated with 7% water-alcohol solution diluted in water given ad libitum in an amber bottle; GAVAGE – mice treated with medication highly diluted 17 DH T. cruzi from 4 th to 9 th day of infection by gavage; WATER - mice treated with highly diluted medication 17 DH T. cruzi in water ad libitum offered in an amber bottle until the end of the study period. The groups were infected with the Y strain of T. cruzi, intraperitoneal, 1400 blood trypomastigotes. The medicines was handled according to the Brazilian Homeopathic Pharmacopoeia [6] with microbiological test according to RDC n°. 67 and in vivo biological risk. Parasitemic curve was determined by daily counting of the parasites [7], the total parasitemia, peak parasites and survival. Data were compared using the BioEstat 5.0, ANOVA, with significance of 5%. The experiment was approved under the protocol n° 030/2008 - Ethics in Animal Experimentation of the Universidade Estadual de Maringá. Results: Animals treated with the medication

  2. Genetic Variability and Phylogenetic Relationships within Trypanosoma cruzi I Isolated in Colombia Based on Miniexon Gene Sequences

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    Claudia Herrera

    2009-01-01

    Full Text Available Phylogenetic studies of Trypanosoma cruzi have identified the existence of two groups: T. cruzi I and T. cruzi II. There are aspects that still remain unknown about the genetic variability within the T. cruzi I group. Given its epidemiological importance, it is necessary to have a better understanding of T. cruzi transmission cycles. Our purpose was to corroborate the existence of haplotypes within the T. cruzi I group and to describe the genetic variability and phylogenetic relationships, based on single nucleotide polymorphisms (SNPs found in the miniexon gene intergenic region, for the isolates from different hosts and epidemiological transmission cycles in Colombian regions. 31 T. cruzi isolates were molecularly characterized. Phylogenetic relationships within T. cruzi I isolates showed four haplotype groups (Ia–Id, associated with their transmission cycle. In previous studies, we reported that haplotype Ia is mainly associated with the domestic cycle and domiciliated Rhodnius prolixus. Haplotype Ib is associated with the domestic cycle and peridomestic cycle, haplotype Ic is closely related with the peridomestic cycle, and haplotype Id is strongly associated with the sylvatic cycle. The phylogenetic methodologies applied in this study are tools that bolster the associations among isolates and thus shed light on Chagas disease epidemiology.

  3. Trypanosoma cruzi strains from triatomine collected in Bahia and Rio Grande do Sul, Brazil

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    Aline Rimoldi Ribeiro

    2014-04-01

    Full Text Available OBJECTIVE Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01, Triatoma melanocephala (11, T. lenti (94, T. pseudomaculata (02, T. sherlocki (26 and T. sordida (460, and two in cities in Rio Grande do Sul, namely T. circummaculata (11 and T. rubrovaria (115. Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one, T. lenti (one, T. rubrovaria (16 and T. sordida (10. Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.

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

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    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.

  5. Epidemiology of American Tegumentary Leishmaniasis and Trypanosoma cruzi Infection in the Northwestern Argentina

    Science.gov (United States)

    Hoyos, Carlos L.; Cajal, Silvana P.; Juarez, Marisa; Marco, Jorge D.; Alberti D'Amato, Anahí M.; Cayo, Melina; Torrejón, Irma; Cimino, Rubén O.; Diosque, Patricio; Nasser, Julio R.

    2016-01-01

    Background. Endemic areas of tegumentary leishmaniasis (TL) in Salta, Argentina, present some overlap zones with the geographical distribution of Chagas disease, with mixed infection cases being often detected. Objectives. The purpose of this study was to determine the magnitude of Leishmania sp. infection and potential associated risk factors, the serologic prevalence of T. cruzi, and the presence of T. cruzi-Leishmania sp. mixed infection in a region of the northwest of Argentina. Methods. Cross-sectional studies were conducted to detect TL prevalence and T. cruzi seroprevalence. A case-control study was conducted to examine leishmaniasis risk factors. Results. Prevalence of TL was 0.17%, seroprevalence of T. cruzi infection was 9.73%, and mixed infection proportion—within the leishmaniasic patients group—was 16.67%. The risk factors associated with TL transmission were sex, age, exposure to bites at work, staying outdoors more than 10 hours/day, bathing in the river, and living with people who had lesions or were infected during the study. Discussion. The endemic pattern of TL seems to involve exposure of patients to vectors in wild as well as peridomestic environment. Cases of T. cruzi infection are apparently due to migration. Therefore, a careful epidemiological surveillance is necessary due to the contraindication of antimonial administration to chagasic patients. PMID:27777950

  6. Trypanosoma cruzi in the sylvatic environment: distinct transmission cycles involving two sympatric marsupials.

    Science.gov (United States)

    Pinho, A P; Cupolillo, E; Mangia, R H; Fernandes, O; Jansen, A M

    2000-01-01

    Thirty-five specimens of Philander frenata and 36 Didelphis marsupialis were captured in the same Atlantic forest area of Brazil between 1992 and 1994. Haemocultures showed that 50% of P. frenata and 60% of D. marsupialis were infected with Trypansoma cruzi. Biological, biochemical and molecular characterization of the isolates suggested 2 distinct transmission cycles of T. cruzi occurred between these 2 sympatric didelphids. The T. cruzi isolates could be distinguished according to their association with each marsupial species. Biochemical characterization (multilocus enzyme electrophoresis) revealed 15 zymodemes; more variability was observed among the P. frenata isolates than among the isolates from D. marsupialis. The course of natural and experimental infection in D. marsupialis and P. frenata was different and suggested that D. marsupialis was more resistant to infection than P. frenata. In the studied area, P. frenata seems to be a more important reservoir of T. cruzi than D. marsupialis, since 40% of the characterized isolates from P. frenata belonged to the T. cruzi II group, which is associated with human infections. PMID:11132378

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

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    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

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

    2015-11-01

    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 Rhodnius 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.

  10. Investigação de anticorpos contra Sarcocystis neurona e Sarcocystis cruzi em equinos

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    A. M. Antonello

    2015-10-01

    Full Text Available ABSTRACTSarcocystis neurona is the primary agent for Equine Protozoal Myeloencephalitis (EPM, important neurological disease characterized by behavior or muscular changes, that impairs animal performance and husbandry. Sarcocystis cruzi is a pathogen related to myositis in cattle. Although related the life cycles of the parasites are distinct. S. neurona has opossums (Didelphis spp. and S. cruzi, dogs as definitive hosts. However, S. neurona and S. cruzi may undergo cross-reactivity in serological tests, interfering on results of EPM ante-mortem diagnostic tests. In the present study, serology of 189 mares was performed by indirect immunofluorescence antibody test, using antigens of S. neurona and S. cruzi in order to assess the exposure degree of animals to antigens. Analyzing the results, it was observed that most of the animals (84.13% reacted with at least one protozoal species and the number of animals which showed antibodies against S. cruzi was greater than S. neurona (80.42% and 33.86%, respectively and a third of seropositive animals reacted to antigens of both species.

  11. The multiple and complex and changeable scenarios of the Trypanosoma cruzi transmission cycle in the sylvatic environment.

    Science.gov (United States)

    Jansen, Ana Maria; Xavier, Samanta C C; Roque, André Luiz R

    2015-11-01

    In this study, we report and discuss the results generated from over 20 years of studies of the Trypanosoma cruzi sylvatic transmission cycle. Our results have uncovered new aspects and reviewed old concepts on issues including reservoirs, true generalist species, association of mammalian species with distinct discrete typing units - DTUs, distribution of T. cruzi genotypes in the wild, mixed infections, and T. cruzi transmission ecology. Using parasitological and serological tests, we examined T. cruzi infection in 7,285 mammalian specimens from nine mammalian orders dispersed all over the Brazilian biomes. The obtained T. cruzi isolates were characterized by mini-exon gene sequence polymorphism and PCR RFLP to identify DTUs. Infection by T. cruzi was detected by serological methods in 20% of the examined animals and isolated from 41% of those infected, corresponding to 8% of all the examined mammals. Each mammal taxon responded uniquely to T. cruzi infection. Didelphis spp. are able to maintain high and long-lasting parasitemias (positive hemocultures) caused by TcI but maintain and rapidly control parasitemias caused by TcII to almost undetectable levels. In contrast, the tamarin species Leontopithecus rosalia and L. chrysomelas maintain long-lasting and high parasitemias caused by TcII similarly to Philander sp. The coati Nasua nasua maintains high parasitemias by both parental T. cruzi DTUs TcI or TcII and by TcII/TcIV (formerly Z3) at detectable levels. Wild and domestic canidae seem to display only a short period of reservoir competence. T. cruzi infection was demonstrated in the wild canid species Cerdocyon thous and Chrysocyon brachyurus, and positive hemoculture was obtained in one hyper carnivore species (Leopardus pardalis), demonstrating that T. cruzi transmission is deeply immersed in the trophic net. T. cruzi DTU distribution in nature did not exhibit any association with a particular biome or habitat. TcI predominates throughout (58% of the T. cruzi

  12. Emerging Chagas disease: trophic network and cycle of transmission of Trypanosoma cruzi from palm trees in the Amazon.

    Science.gov (United States)

    Teixeira, A R; Monteiro, P S; Rebelo, J M; Argañaraz, E R; Vieira, D; Lauria-Pires, L; Nascimento, R; Vexenat, C A; Silva, A R; Ault, S K; Costa, J M

    2001-01-01

    A trophic network involving molds, invertebrates, and vertebrates, ancestrally adapted to the palm tree (Attalaea phalerata) microhabitat, maintains enzootic Trypanosoma cruzi infections in the Amazonian county Paço do Lumiar, state of Maranhão, Brazil. We assessed seropositivity for T. cruzi infections in the human population of the county, searched in palm trees for the triatomines that harbor these infections, and gathered demographic, environmental, and socioeconomic data. Rhodnius pictipes and R. neglectus in palm-tree frond clefts or in houses were infected with T. cruzi (57% and 41%, respectively). Human blood was found in 6.8% of R. pictipes in houses, and 9 of 10 wild Didelphis marsupialis had virulent T. cruzi infections. Increasing human population density, rain forest deforestation, and human predation of local fauna are risk factors for human T. cruzi infections. PMID:11266300

  13. Aspects of resistance to experimental infection with Trypanosoma cruzi

    International Nuclear Information System (INIS)

    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

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

    Directory of Open Access Journals (Sweden)

    Sergio Sosa-Estani

    2009-10-01

    Full Text Available 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 nacidos de mujeres infectadas durante el período de estudio. La tasa de infestación en 172 viviendas evaluadas en 2006 alcanzó el 32%. La prevalencia de infección en 445 personas fue de 17.5% y en menores de 5 años de edad fue 8.6%. La tasa de infección en donantes de sangre alcanzó a 18.6% y en mujeres embarazadas fue 29.1%. La tasa de infección considerada congénita en 47 niños nacidos de mujeres infectadas residentes en viviendas bajo vigilancia fue de 17.0%. El estudio mostró, al momento de su inicio, índices compatibles con transmisión vectorial activa. Después del control vectorial con insecticidas, la tasa de infestación se redujo a 3.3%. El sistema de salud local incorporó procedimientos de prevención primaria y secundaria para evitar nuevos casos e instaurar el tratamiento de la población infectada.Chagas disease, caused by Trypanosoma cruzi, is a major cause of morbidity and mortality in Latin America. The objective of this study was to describe the rate of infestation in four aboriginal communities in Las Lomitas (Great Chaco Region, Formosa, Argentina; the rate of infection in children residing in these communities, in blood donors and in pregnant women who received care at the Hospital Las Lomitas, as well as the rate of congenital infection in children born to women infected during the study period. The rate of infestation of 172 households evaluated in 2006 reached 32%. Prevalence of infection among 445 people was 17

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

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    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. The population genetics of Trypanosoma cruzi revisited in the light of the predominant clonal evolution model.

    Science.gov (United States)

    Tibayrenc, Michel; Ayala, Francisco J

    2015-11-01

    Comparing the population structure of Trypanosoma cruzi with that of other pathogens, including parasitic protozoa, fungi, bacteria and viruses, shows that the agent of Chagas disease shares typical traits with many other species, related to a predominant clonal evolution (PCE) pattern: statistically significant linkage disequilibrium, overrepresented multilocus genotypes, near-clades (genetic subdivisions somewhat blurred by occasional genetic exchange/hybridization) and "Russian doll" patterns (PCE is observed, not only at the level of the whole species, but also, within the near-clades). Moreover, T. cruzi population structure exhibits linkage with the diversity of several strongly selected genes, with gene expression profiles, and with some major phenotypic traits. We discuss the evolutionary significance of these results, and their implications in terms of applied research (molecular epidemiology/strain typing, analysis of genes of interest, vaccine and drug design, immunological diagnosis) and of experimental evolution. Lastly, we revisit the long-term debate of describing new species within the T. cruzi taxon.

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  2. Estudo dos caracteres de uma amostra boliviana de Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Gentilda K. Funayama

    1974-04-01

    Full Text Available Amostra de T. cruzi, mediante a inoculação em camundongos brancos jovens, foi isolada de fezes de exemplares de T. infestans capturados em Vitichi, Bolívia e denominada amostra Bolívia. Essa amostra, que se comporta de um modo peculiar em reações de aglutinação, segundo Siqueira, Ribeiro e Fernandes, em 1973, mostrou-se patogênica para camundongos, infectando 100% dos animais inoculados, quer com formas metacíclicas de triatomíneos, quer com formas sanguícolas de doadores com infecção aguda. As formas sanguícolas, em camundongos, medem 23,37 μ de comprimento total médio e tem índice nuclear de 0,94. Nos camundongos mortos durante a fase aguda os ninhos de leishmânias são abundantes, sobretudo no coração. A infecção dos camundongos é grave com curto período prepatente, parasitemia elevada e alta taxa de letalidade. A amostra Bolívia confere, aos animais que sobrevivem, alto grau de resistência contra reinfecção pela amostra Y. Cultiva-se bem em meios líquidos (Warren e difásicos (NNN e evolui regularmente em várias espécies de triatomíneos testadas.

  3. [Maternal-fetal transmission of Trypanosoma cruzi in Argentina].

    Science.gov (United States)

    de Rissio, Ana María; Scollo, Karenina; Cardoni, Rita L

    2009-01-01

    In the neonates born to T. cruzi infected mothers, the diagnosis of the congenital transmission relays on the detection of the parasites and/or the specific antibodies non-transferred by their mothers, in the absence of blood transfusion and vectorial transmission. In the early stage, approximately until the 7th month of life, when maternal immunoglobulins could be present, the diagnosis depends on the detection of the parasite. Then, in the late stage, from the 8th month, the detection of specific antibodies by at least 2 of 3 serological tests confirms the infection in the neonates. The diagnostic follow up of the children born to a group of sero-reactive pregnant women was carried out in the INP. The 11% of the mothers (29 out of 267) transmitted the infection to their children. The neonates of 20 of these mothers were diagnosed in the early stage, 14 and 6 in one or two controls, respectively. In the 9 remaining mothers the children were diagnosed in the late stage of the infection, mainly serologicaly. Our analisis of previously published reports stressed that the maternal-fetal transmission rate depends on the time of diagnostic follow up of the child. In this reports, mean values of mother to child transmission reported was 2% and 9% when the diagnosis of the neonates born to sero-reactive mothers was carried out only in the early stage or in the early and also the late stage, respectively. PMID:19897438

  4. Development of an aptamer-based concentration method for the detection of Trypanosoma cruzi in blood.

    Directory of Open Access Journals (Sweden)

    Rana Nagarkatti

    Full Text Available Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8-25 nM range. The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood.

  5. Development of an Aptamer-Based Concentration Method for the Detection of Trypanosoma cruzi in Blood

    Science.gov (United States)

    Nagarkatti, Rana; Bist, Vaibhav; Sun, Sirena; Fortes de Araujo, Fernanda; Nakhasi, Hira L.; Debrabant, Alain

    2012-01-01

    Trypanosoma cruzi, a blood-borne parasite, is the etiological agent of Chagas disease. T. cruzi trypomastigotes, the infectious life cycle stage, can be detected in blood of infected individuals using PCR-based methods. However, soon after a natural infection, or during the chronic phase of Chagas disease, the number of parasites in blood may be very low and thus difficult to detect by PCR. To facilitate PCR-based detection methods, a parasite concentration approach was explored. A whole cell SELEX strategy was utilized to develop serum stable RNA aptamers that bind to live T. cruzi trypomastigotes. These aptamers bound to the parasite with high affinities (8–25 nM range). The highest affinity aptamer, Apt68, also demonstrated high specificity as it did not interact with the insect stage epimastigotes of T. cruzi nor with other related trypanosomatid parasites, L. donovani and T. brucei, suggesting that the target of Apt68 was expressed only on T. cruzi trypomastigotes. Biotinylated Apt68, immobilized on a solid phase, was able to capture live parasites. These captured parasites were visible microscopically, as large motile aggregates, formed when the aptamer coated paramagnetic beads bound to the surface of the trypomastigotes. Additionally, Apt68 was also able to capture and aggregate trypomastigotes from several isolates of the two major genotypes of the parasite. Using a magnet, these parasite-bead aggregates could be purified from parasite-spiked whole blood samples, even at concentrations as low as 5 parasites in 15 ml of whole blood, as detected by a real-time PCR assay. Our results show that aptamers can be used as pathogen specific ligands to capture and facilitate PCR-based detection of T. cruzi in blood. PMID:22927983

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

    Science.gov (United States)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Trypanosoma cruzi Experimental Infection Impacts on the Thymic Regulatory T Cell Compartment

    Science.gov (United States)

    González, Florencia Belén; Calmon-Hamaty, Flavia; Nô Seara Cordeiro, Synara; Fernández Bussy, Rodrigo; Spinelli, Silvana Virginia; D'Attilio, Luciano; Bottasso, Oscar; Savino, Wilson; Cotta-de-Almeida, Vinícius; Villar, Silvina Raquel; Pérez, Ana Rosa

    2016-01-01

    The dynamics of regulatory T cells in the course of Trypanosoma cruzi infection is still debated. We previously demonstrated that acute murine T. cruzi infection results in an impaired peripheral CD4+Foxp3+ T cell differentiation due to the acquisition of an abnormal Th1-like phenotype and altered functional features, negatively impacting on the course of infection. Moreover, T. cruzi infection induces an intense thymic atrophy. As known, the thymus is the primary lymphoid organ in which thymic-derived regulatory T cells, known as tTregs, differentiate. Considering the lack of available data about the effect of T. cruzi infection upon tTregs, we examined tTreg dynamics during the course of disease. We confirmed that T. cruzi infection induces a marked loss of tTreg cell number associated to cell precursor exhaustion, partially avoided by glucocorticoid ablation- and IL-2 survival factor depletion. At the same time, tTregs accumulate within the CD4 single-positive compartment, exhibiting an increased Ki-67/Annexin V ratio compared to controls. Moreover, tTregs enhance after the infection the expression of signature markers (CD25, CD62L and GITR) and they also display alterations in the expression of migration-associated molecules (α chains of VLAs and chemokine receptors) such as functional fibronectin-driven migratory disturbance. Taken together, we provide data demonstrating profound alterations in tTreg compartment during acute murine T. cruzi infection, denoting that their homeostasis is significantly affected. The evident loss of tTreg cell number may compromise the composition of tTreg peripheral pool, and such sustained alteration over time may be partially related to the immune dysregulation observed in the chronic phase of the disease. PMID:26745276

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Inositol metabolism in Trypanosoma cruzi: potential target for chemotherapy against Chagas' disease

    Directory of Open Access Journals (Sweden)

    MECIA M. OLIVEIRA

    2000-09-01

    Full Text Available Chagas' disease is a debilitating and often fatal disease caused by the protozoan parasite Trypanosoma cruzi. The great majority of surface molecules in trypanosomes are either inositol-containing phospholipids or glycoproteins that are anchored into the plasma membrane by glycosylphosphatidylinositol anchors. The polyalcohol myo-inositol is the precursor for the biosynthesis of these molecules. In this brief review, recent findings on some aspects of the molecular and cellular fate of inositol in T. cruzi life cycle are discussed and identified some points that could be targets for the development of parasite-specific therapeutic agents.

  11. Efeito inibitório de óleos essenciais sobre Trypanosoma cruzi

    OpenAIRE

    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...

  12. Trypanosoma cruzi alkaline 2-DE: Optimization and application to comparative proteome analysis of flagellate life stages

    Directory of Open Access Journals (Sweden)

    Santana Jaime M

    2008-09-01

    Full Text Available Abstract Background Trypanosoma cruzi, a flagellate protozoan, is the etiological agent of Chagas disease, a chronic illness that causes irreversible damage to heart and digestive tract in humans. Previous 2-DE analyses of T. cruzi proteome have not focused on basic proteins, possibly because of inherent difficulties for optimizing 2-DE in the alkaline pH range. However, T. cruzi wide pH range 2-DE gels have shown few visible spots in the alkaline region, indicating that the parasite either did not have an appreciable amount of alkaline proteins or that these proteins were underrepresented in the 2-DE gels. Results Different IEF conditions using 6–11 pH gradient strips were tested for separation of T. cruzi alkaline proteins. The optimized methodology described here was performed using anodic "paper bridge" sample loading supplemented by increased concentration of DTT and Triton X-100 on Multiphor II (GE Healthcare equipment and an electrode pad embedded in DTT- containing solution near the cathode in order to avoid depletion of reducing agent during IEF. Landmark proteins were identified by peptide mass fingerprinting allowing the production of an epimastigote 2-DE map. Most identified proteins corresponded to metabolic enzymes, especially those related to amino acid metabolism. The optimized 2-DE protocol was applied in combination with the "two-in-one gel" method to verify the relative expression of the identified proteins between samples from epimastigote and trypomastigote life stages. Conclusion High resolution 2-DE gels of T. cruzi life forms were achieved using the optimized methodology and a partial epimastigote alkaline 2-DE map was built. Among 700 protein spots detected, 422 were alkaline with a pI above 7.0. The "two-in-one gel" method simplified the comparative analysis between T. cruzi life stages since it minimized variations in spot migration and silver-stained spot volumes. The comparative data were in agreement with

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    DEFF Research Database (Denmark)

    Queiroz, Rayner M L; Charneau, Sébastien; Motta, Flávia N;

    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...... plasma membrane protein, two distinct methodologies were optimized and evaluated. The first methodology was based on cell surface trypsinization (Shave) of intact living cells while the second approach used biotinylation of cell surface proteins followed by streptavidin affinity chromatography isolation...

  16. Trypanosoma cruzi Intracellular Amastigotes Isolated by Nitrogen Decompression Are Capable of Endocytosis and Cargo Storage in Reservosomes.

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    Cassiano Martin Batista

    Full Text Available Epimastigote forms of Trypanosoma cruzi (the etiologic agent of Chagas disease internalize and store extracellular macromolecules in lysosome-related organelles (LROs called reservosomes, which are positive for the cysteine protease cruzipain. Despite the importance of endocytosis for cell proliferation, macromolecule internalization remains poorly understood in the most clinically relevant proliferative form, the intracellular amastigotes found in mammalian hosts. The main obstacle was the lack of a simple method to isolate viable intracellular amastigotes from host cells. In this work we describe the fast and efficient isolation of viable intracellular amastigotes by nitrogen decompression (cavitation, which allowed the analysis of amastigote endocytosis, with direct visualization of internalized cargo inside the cells. The method routinely yielded 5x10(7 amastigotes--with typical shape and positive for the amastigote marker Ssp4--from 5x10(6 infected Vero cells (48 h post-infection. We could visualize the endocytosis of fluorescently-labeled transferrin and albumin by isolated intracellular amastigotes using immunofluorescence microscopy; however, only transferrin endocytosis was detected by flow cytometry (and was also analyzed by western blotting, suggesting that amastigotes internalized relatively low levels of albumin. Transferrin binding to the surface of amastigotes (at 4°C and its uptake (at 37°C were confirmed by binding dissociation assays using acetic acid. Importantly, both transferrin and albumin co-localized with cruzipain in amastigote LROs. Our data show that isolated T. cruzi intracellular amastigotes actively ingest macromolecules from the environment and store them in cruzipain-positive LROs functionally related to epimastigote reservosomes.

  17. TNF-α is involved in the abnormal thymocyte migration during experimental Trypanosoma cruzi infection and favors the export of immature cells.

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    Ana Rosa Pérez

    Full Text Available Previous studies revealed a significant production of inflammatory cytokines together with severe thymic atrophy and thymocyte migratory disturbances during experimental Chagas disease. Migratory activity of thymocytes and mature T cells seem to be finely tuned by cytokines, chemokines and extracellular matrix (ECM components. Systemic TNF-α is enhanced during infection and appears to be crucial in the response against the parasite. However, it also seems to be involved in disease pathology, since it is implicated in the arrival of T cells to effector sites, including the myocardium. Herein, we analyzed the role of TNF-α in the migratory activity of thymocytes in Trypanosoma cruzi (T. cruzi acutely-infected mice. We found increased expression and deposition of TNF-α in the thymus of infected animals compared to controls, accompanied by increased co-localization of fibronectin, a cell migration-related ECM molecule, whose contents in the thymus of infected mice is also augmented. In-vivo studies showed an enhanced export of thymocytes in T. cruzi-infected mice, as ascertained by intrathymic injection of FITC alone or in combination with TNF-α. The increase of immature CD4(+CD8(+ T cells in secondary lymphoid organs was even more clear-cut when TNF-α was co-injected with FITC. Ex-vivo transmigration assays also revealed higher number of migrating cells when TNF-α was added onto fibronectin lattices, with higher input of all thymocyte subsets, including immature CD4(+CD8(+. Infected animals also exhibit enhanced levels of expression of both mRNA TNF-α receptors in the CD4(+CD8(+ subpopulation. Our findings suggest that in T. cruzi acute infection, when TNF-α is complexed with fibronectin, it favours the altered migration of thymocytes, promoting the release of mature and immature T cells to different compartments of the immune system. Conceptually, this work reinforces the notion that thymocyte migration is a multivectorial biological event

  18. Bradykinin B2 Receptors of dendritic cells, acting as sensors of kinins proteolytically released by Trypanosoma cruzi, are critical for the development of protective type-1 responses.

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    Ana Carolina Monteiro

    2007-11-01

    Full Text Available Although the concept that dendritic cells (DCs recognize pathogens through the engagement of Toll-like receptors is widely accepted, we recently suggested that immature DCs might sense kinin-releasing strains of Trypanosoma cruzi through the triggering of G-protein-coupled bradykinin B2 receptors (B2R. Here we report that C57BL/6.B2R-/- mice infected intraperitoneally with T. cruzi display higher parasitemia and mortality rates as compared to B2R+/+ mice. qRT-PCR revealed a 5-fold increase in T. cruzi DNA (14 d post-infection [p.i.] in B2R-/- heart, while spleen parasitism was negligible in both mice strains. Analysis of recall responses (14 d p.i. showed high and comparable frequencies of IFN-gamma-producing CD4+ and CD8+ T cells in the spleen of B2R-/- and wild-type mice. However, production of IFN-gamma by effector T cells isolated from B2R-/- heart was significantly reduced as compared with wild-type mice. As the infection continued, wild-type mice presented IFN-gamma-producing (CD4+CD44+ and CD8+CD44+ T cells both in the spleen and heart while B2R-/- mice showed negligible frequencies of such activated T cells. Furthermore, the collapse of type-1 immune responses in B2R-/- mice was linked to upregulated secretion of IL-17 and TNF-alpha by antigen-responsive CD4+ T cells. In vitro analysis of tissue culture trypomastigote interaction with splenic CD11c+ DCs indicated that DC maturation (IL-12, CD40, and CD86 is controlled by the kinin/B2R pathway. Further, systemic injection of trypomastigotes induced IL-12 production by CD11c+ DCs isolated from B2R+/+ spleen, but not by DCs from B2R-/- mice. Notably, adoptive transfer of B2R+/+ CD11c+ DCs (intravenously into B2R-/- mice rendered them resistant to acute challenge, rescued development of type-1 immunity, and repressed TH17 responses. Collectively, our results demonstrate that activation of B2R, a DC sensor of endogenous maturation signals, is critically required for development of acquired

  19. Early double-negative thymocyte export in Trypanosoma cruzi infection is restricted by sphingosine receptors and associated with human chagas disease.

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    Ailin Lepletier

    2014-10-01

    Full Text Available The protozoan parasite Trypanosoma cruzi is able to target the thymus and induce alterations of the thymic microenvironmental and lymphoid compartments. Acute infection results in severe atrophy of the organ and early release of immature thymocytes into the periphery. To date, the pathophysiological effects of thymic changes promoted by parasite-inducing premature release of thymocytes to the periphery has remained elusive. Herein, we show that sphingosine-1-phosphate (S1P, a potent mediator of T cell chemotaxis, plays a role in the exit of immature double-negative thymocytes in experimental Chagas disease. In thymuses from T. cruzi-infected mice we detected reduced transcription of the S1P kinase 1 and 2 genes related to S1P biosynthesis, together with increased transcription of the SGPL1 sphingosine-1-lyase gene, whose product inactivates S1P. These changes were associated with reduced intrathymic levels of S1P kinase activity. Interestingly, double-negative thymocytes from infected animals expressed high levels of the S1P receptor during infection, and migrated to lower levels of S1P. Moreover, during T. cruzi infection, this thymocyte subset expresses high levels of IL-17 and TNF-α cytokines upon polyclonal stimulation. In vivo treatment with the S1P receptor antagonist FTY720 resulted in recovery the numbers of double-negative thymocytes in infected thymuses to physiological levels. Finally, we showed increased numbers of double-negative T cells in the peripheral blood in severe cardiac forms of human Chagas disease.

  20. Phenotypic Features of Circulating Leukocytes from Non-human Primates Naturally Infected with Trypanosoma cruzi Resemble the Major Immunological Findings Observed in Human Chagas Disease.

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    Renato Sathler-Avelar

    2016-01-01

    Full Text Available Cynomolgus macaques (Macaca fascicularis represent a feasible model for research on Chagas disease since natural T. cruzi infection in these primates leads to clinical outcomes similar to those observed in humans. However, it is still unknown whether these clinical similarities are accompanied by equivalent immunological characteristics in the two species. We have performed a detailed immunophenotypic analysis of circulating leukocytes together with systems biology approaches from 15 cynomolgus macaques naturally infected with T. cruzi (CH presenting the chronic phase of Chagas disease to identify biomarkers that might be useful for clinical investigations.Our data established that CH displayed increased expression of CD32+ and CD56+ in monocytes and enhanced frequency of NK Granzyme A+ cells as compared to non-infected controls (NI. Moreover, higher expression of CD54 and HLA-DR by T-cells, especially within the CD8+ subset, was the hallmark of CH. A high level of expression of Granzyme A and Perforin underscored the enhanced cytotoxicity-linked pattern of CD8+ T-lymphocytes from CH. Increased frequency of B-cells with up-regulated expression of Fc-γRII was also observed in CH. Complex and imbricate biomarker networks demonstrated that CH showed a shift towards cross-talk among cells of the adaptive immune system. Systems biology analysis further established monocytes and NK-cell phenotypes and the T-cell activation status, along with the Granzyme A expression by CD8+ T-cells, as the most reliable biomarkers of potential use for clinical applications.Altogether, these findings demonstrated that the similarities in phenotypic features of circulating leukocytes observed in cynomolgus macaques and humans infected with T. cruzi further supports the use of these monkeys in preclinical toxicology and pharmacology studies applied to development and testing of new drugs for Chagas disease.

  1. The ecology of the Trypanosoma cruzi transmission cycle: Dispersion of zymodeme 3 (Z3) in wild hosts from Brazilian biomes.

    Science.gov (United States)

    Lisboa, Cristiane Varella; Xavier, Samanta Cristina das Chagas; Herrera, Heitor Miraglia; Jansen, Ana Maria

    2009-10-28

    Two main genotypes in Trypanosoma cruzi subpopulations can be distinguished by PCR amplification of sequences from the mini-exon gene non-transcribed spacer, respectively, T. cruzi I (TCI) and T. cruzi II (TCII). This technique is also capable of distinguishing a third assemblage of subpopulations that do not fit in these genotypes and that remain known as zymodeme Z3 (Z3). The distribution pattern as well as the mammalian host range of this latter T. cruzi sublineage still remains unclear. Thus, the intention of our study was to increase the information regarding these aspects. The mini-exon analysis of T. cruzi isolates obtained from sylvatic animals in the Amazon Forest, Atlantic Rainforest, Caatinga and Pantanal showed that prevalence of the Z3 subpopulation in nature was low (15 out of 225 isolates, corresponding to 7%). A higher prevalence of Z3 was observed in the Caatinga (15%) and the Pantanal (12%). Infection by Z3 was observed in mammalian hosts included in Carnivora, Chiroptera, Didelphimorphia, Rodentia and Xernathra. The T. cruzi Z3 subpopulation was observed also in mixed infections (33%) with TCI (n=2) and TCII (n=3). These results demonstrate that T. cruzi Z3 displays a wider distribution and host range than formerly understood as it has been demonstrated to be able infect species included in five orders of mammalian host species dispersed through all forest strata of the four Brazilian biomes evaluated.

  2. Immunofluorescent Antibody Test (IFAT for Trypanosoma cruzi in dogs from urban and rural areas of Pelotas, RS

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    Charlene Nascimento dos Santos

    2015-07-01

    Full Text Available Chagas disease (CD is a zoonosis with the protozoan Trypanosoma cruzi as the causative agent. Dogs are considered the main domestic reservoir for T. cruzi in most Latin American countries and in some areas of the United States. In southern Brazil, despite being an endemic area of the disease, the prevalence in dogs is still unknown. This study aimed to evaluate the frequency of T. cruzi antibodies in dogs from urban and rural areas of Pelotas, RS, Brazil. A total of 227 canine sera were used for serological tests, of which 99 were from urban areas and 128 were from rural areas of Pelotas. Information regarding the environment and the possible risk factors (origin, rural contact, age, breed, confinement and gender to which the dogs were exposed were recorded. Indirect immunofluorescence was used to assess the presence of specific immunoglobulins (IgG anti-T. cruzi in the serum of dogs. Of the 227 sera analyzed, 81 (35.7% exhibited anti-T. cruzi, which represented 34.3% of the dogs from the urban area and 36.7% of the dogs from the rural area. Among the variables analyzed, rural contact and male gender showed an association with seropositivity for T. cruzi. The detection of T. cruzi antibodies in the serum of these dogs emphasizes the need to study trypanosomiasis in this important domestic reservoir of Chagas disease.

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

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    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.

  4. Genome-wide screening and identification of new Trypanosoma cruzi antigens with potential application for chronic Chagas disease diagnosis.

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    João Luís Reis-Cunha

    Full Text Available The protozoan Trypanosoma cruzi is the etiologic agent of Chagas disease, an infection that afflicts approximately 8 million people in Latin America. Diagnosis of chronic Chagas disease is currently based on serological tests because this condition is usually characterized by high anti-T. cruzi IgG titers and low parasitemia. The antigens used in these assays may have low specificity due to cross reactivity with antigens from related parasite infections, such as leishmaniasis, and low sensitivity caused by the high polymorphism among T. cruzi strains. Therefore, the identification of new T. cruzi-specific antigens that are conserved among the various parasite discrete typing units (DTUs is still required. In the present study, we have explored the hybrid nature of the T. cruzi CL Brener strain using a broad genome screening approach to select new T. cruzi antigens that are conserved among the different parasite DTUs and that are absent in other trypanosomatid species. Peptide arrays containing the conserved antigens with the highest epitope prediction scores were synthesized, and the reactivity of the peptides were tested by immunoblot using sera from C57BL/6 mice chronically infected with T. cruzi strains from the TcI, TcII or TcVI DTU. The two T. cruzi proteins that contained the most promising peptides were expressed as recombinant proteins and tested in ELISA experiments with sera from chagasic patients with distinct clinical manifestations: those infected with T. cruzi from different DTUs and those with cutaneous or visceral leishmaniasis. These proteins, named rTc_11623.20 and rTc_N_10421.310, exhibited 94.83 and 89.66% sensitivity, 98.2 and 94.6% specificity, respectively, and a pool of these 2 proteins exhibited 96.55% sensitivity and 98.18% specificity. This work led to the identification of two new antigens with great potential application in the diagnosis of chronic Chagas disease.

  5. Higher frequency of administration of biotherapic T. cruzi 17DH decreases parasitemia and increases survival in mice infected with Trypanosoma cruzi

    OpenAIRE

    ÃÂurea Regina Telles Pupulin; Silvana Marques Araujo; Mônica Lúcia Gomes; Camila Fernanda Brustolin; Caroline Felicio Braga; Erika Cristina Ferreira; Denise Lessa Aleixo

    2011-01-01

    Introduction: The study of the effect of different ways of treatment using highly diluted substances is rare in the literature. Some authors consider the dose irrelevant, justifying that the action of the medication highly diluted is qualitative [1-3]. Others emphasize the importance of quantity and frequency of administration of the highly diluted substance for a successful treatment [4,5]. The model of murine infection by T. cruzi is widely studied and it is an excellent tool to study the e...

  6. Inter-relation of sylvatic and domestic transmission of Trypanosoma cruzi in areas with and without domestic vectorial transmission in Minas Gerais, Brazil

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    L. Diotaiuti

    1995-08-01

    Full Text Available During the period 1980-1986, we captured triatomine bugs and mammalian reservoir hosts from sylvatic and domestic situations in different municipalities of the State of Minas Gerais. Trypanosoma cruzi was isolated from captured bugs, mammals and patients. After cultivation in LIT medium, the electrophoretic enzyme profiles were determined. We obtained atotal of 32 parasite isolates from regions with active domestic transmission, and 24 isolates form areas under control. For the first areas the results suggest introduction of T. cruzi from sylvatic habitats, through incursion of infected opossums and/or sylvatic T. sordida, which appears to have given rise to at least one acute human infection. Of particular interest is the finding of sylvatic opossums and a T. sordida nymph infected with ZB, that could indicate return of parasites from chronic human infections to sylvatic transmission cycles. For the areas under control we also interpret the results as interaction between sylvatic and domestic cycles of transmission, here through the invasion of houses by bugs carrying the Z1 zymodeme from the sylvatic environment. The Multivariate Correspondence Analysis gives a spatial description between the different parasite isolates and confirms the existence of a bridge in the opposite direction in the region with active vectorial transmission including the exporting of Z2 through the peridomestic environment into the sylvatic cycle. For the others areas this bridge corresponds especially to Panstrongylus megistus, importing Z1 into the domestic environment.

  7. Electrocardiographic alteration among first degree relatives with serologic evidence of Trypanosoma cruzi infection: a sibship study

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    Julio C. Morini

    1994-09-01

    Full Text Available To analyze whether electrocardiographic alterations (ECGA in patients with antibodies to Trypanosoma cruzi showed a patttern of familial aggregation, a sample of 379 young adults (166 men and 213 women distributed in sibships, were assessed for the presence of anti-T.cruzi antibodies, and subjected to a complete clinical examination and a standard resting electrocardiogram (ECG. Positive T. cruzi serology was detected in 165 individuals, 48 of them showing an abnormal ECG (overall prevalence 29 por cento. One hundred and eleven seropositive individuals were distributed in 45 sibships, each of them constituted by more than one seropositive sib, with ECGA being present in 34 out of these patients. Seropositive subjects with ECGA were detected in 27 sibships. Since the index case within each sibship is counted exactly once, affected individuals selected at random as propositi were extracted to calculate the prevalence of ECGA among first degree relatives of probands. Abnormal ECGs were recorded in 7 out of 45 sibs yielding a prevalence that did not differ from estimations registered in the general population or seropositive sibs. Data from the present sample show no familial aggregation for the occurrence of ECGA in patients with T.cruzi infection.

  8. Maxi-circles and mini-circles in kinetoplast DNA from Trypanosoma cruzi.

    NARCIS (Netherlands)

    W. Leon; A.C.C. Frasch; J.H.J. Hoeijmakers (Jan); F. Fase-Fowler; P. Borst (Piet); F. Brunel; J. Davison

    1980-01-01

    textabstractMaxi-circles are a minor component of kinetoplast DNAs from all trypanosomatids studied, but they have not previously been found in Trypanosoma cruzi; We have spread intact kinetoplast DNA from the epimastigotes of strain Y in protein monolayers and analysed the mini-circle networks by e

  9. Differential expression profiles in the midgut of Triatoma infestans infected with Trypanosoma cruzi.

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    Diego S Buarque

    Full Text Available Chagas disease, or American trypanosomiasis, is a parasitic disease caused by the protozoan Trypanosoma cruzi and is transmitted by insects from the Triatominae subfamily. To identify components involved in the protozoan-vector relationship, we constructed and analyzed cDNA libraries from RNA isolated from the midguts of uninfected and T. cruzi-infected Triatoma infestans, which are major vectors of Chagas disease. We generated approximately 440 high-quality Expressed Sequence Tags (ESTs from each T. infestans midgut cDNA library. The sequences were grouped in 380 clusters, representing an average length of 664.78 base pairs (bp. Many clusters were not classified functionally, representing unknown transcripts. Several transcripts involved in different processes (e.g., detoxification showed differential expression in response to T. cruzi infection. Lysozyme, cathepsin D, a nitrophorin-like protein and a putative 14 kDa protein were significantly upregulated upon infection, whereas thioredoxin reductase was downregulated. In addition, we identified several transcripts related to metabolic processes or immunity with unchanged expressions, including infestin, lipocalins and defensins. We also detected ESTs encoding juvenile hormone binding protein (JHBP, which seems to be involved in insect development and could be a target in control strategies for the vector. This work demonstrates differential gene expression upon T. cruzi infection in the midgut of T. infestans. These data expand the current knowledge regarding vector-parasite interactions for Chagas disease.

  10. Biochemical behavior of Trypanosoma cruzi strains isolated from mice submitted to specific chemotherapy

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    Jesila Pinto M. Marretto

    1994-12-01

    Full Text Available To investigate the influence of chemotherapy on the biochemical beha vior of Trypanosoma cruzi strains, three groups of mice were infected with one of three strains of T. cruzi of different biological and isoenzymic patterns (Peruvian, 21 SF and Colombian strains. Each group was subdivided into subgroups: 1 - treated with nifurtimox; 2 - treated with benznidazole and 3 - untreated infected controls. At the end of treatment, that lasted for 90 days, xenodiagnosis, sub inoculation of blood into new born mice and haemoculture were performed as tests of cure. From the positive tests, 22 samples of T. cruzi were isolated from all subgroups. Electrophoretic analysis of the isoenzymes PGM, GP1, ALAT and AS AT failed to show any difference between parasite strains isolated from treated and untreated mice, which indicates that no detectable clonal selection or parasite genetic markers alterations concerning the isoenzymes analysed have been determined by treatment with drugs of recognized antiparasitic effect, suggesting stability of the phenotypic characteristics of the three biological types of T. cruzi strains.

  11. Trypanosoma cruzi infection in Elche (Spain): comparison of the seroprevalence in immigrants from Paraguay and Bolivia.

    Science.gov (United States)

    Ramos, José M; Ponce, Yamileth; Gallegos, Ingrid; Flóres-Chávez, María; Cañavate, Carmen; Gutiérrez, Félix

    2012-05-01

    Chagas disease is a global public health problem due to the recent emigration of people from Latin America to other regions, including Europe. The aim of this study is to determine the prevalence of Trypanosoma cruzi infection among Paraguayans and Bolivians living in Elche (Spain), a city located in the Mediterranean Coast of Spain. A cross-sectional study was conducted. Capillary blood samples were obtained through a finger prick, and collected on filter paper. An enzyme-linked immunosorbent assay and indirect immunofluorescence tests were performed to search for anti-T. cruzi IgG antibodies in the filter papers. Thirteen out of 201 participants were infected with T. cruzi in this study, seven out of 73 Bolivians and six out of 128 Paraguayans, corresponding to seroprevalences of 9·59% (95%CI, 4·72-18·5%) and 4·69% (95%CI, 2·17-9·85%), respectively. Palpitation, chest pain, and migration from rural endemic areas were the most common clinical and epidemiological risk factors associated with T. cruzi infection detected in the Paraguayan group. This study highlights that Chagas disease is no longer limited to the Bolivian population living in Spain. It is important to note this wider prevalence and, therefore, not discount Paraguayans in the screening for Chagas disease in Spain. Indeed, this should be considered for all immigrants from Latin America.

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    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 t...

  14. Natural populations of Trypanosoma cruzi, the agent of Chagas disease, have a complex multiclonal structure

    Energy Technology Data Exchange (ETDEWEB)

    Tibayrenc, M.; Ward, P.; Moya, A.; Ayala, F.J.

    1986-01-01

    The authors have studied 15 gene loci coding for enzymes in 121 Trypanosoma cruzi stocks from a wide geographic range - from the US and Mexico to Chile and southern Brazil. T.cruzi is diploid but reproduction is basically clonal, with very little if any sexuality remaining at present. They have identified 43 different clones by their genetic composition; the same genetic clone is often found in very distant places and in diverse hosts. There is much genetic heterogeneity among the different clones, and they cannot be readily classified into a few discrete groups that might represent natural taxa. These findings imply that the biological and medical characteristics need to be ascertained separately for each natural clone. The evidence indicates that clonal evolution is very ancient in T.cruzi. The authors propose two alternative hypotheses concerning the relationship between the biochemical diversity and the heterogeneity in other biological and medical characteristics of T. cruzi. One hypothesis is that the degree of diversity between strains simply reflects the time elapsed since their last common ancestor. The second hypothesis is that biological and medical heterogeneity is recent and reflects adaptation to different transmission cycles. A decision between the two hypotheses can be reached with appropriate studies, with important medical consequences.

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

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    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.

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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

  18. The effect of the diterpene 5-epi-icetexone on the cell cycle of Trypanosoma cruzi.

    NARCIS (Netherlands)

    Lozano, E.; Barrera, P.; Tonn, C.; Nieto, M.; Sartor, T.; Sosa, M.A.

    2012-01-01

    Numerous natural compounds have been used against Trypanosoma cruzi, the causative agent of Chagas' disease. Here, we studied the effect of the diterpene 5-epi-icetexone on growth and morphology of parasites synchronized with hydroxyurea, at different periods of time after removal of the nucleotide.

  19. Visual genome-wide RNAi screening to identify human host factors required for Trypanosoma cruzi infection.

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    Auguste Genovesio

    Full Text Available The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy.

  20. Biochemical behavior of Trypanosoma cruzi strains isolated from mice submitted to specific chemotherapy

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    Jesila Pinto M. Marretto

    1994-12-01

    Full Text Available To investigate the influence of chemotherapy on the biochemical beha vior of Trypanosoma cruzi strains, three groups of mice were infected with one of three strains of T. cruzi of different biological and isoenzymic patterns (Peruvian, 21 SF and Colombian strains. Each group was subdivided into subgroups: 1 - treated with nifurtimox; 2 - treated with benznidazole and 3 - untreated infected controls. At the end of treatment, that lasted for 90 days, xenodiagnosis, sub inoculation of blood into new born mice and haemoculture were performed as tests of cure. From the positive tests, 22 samples of T. cruzi were isolated from all subgroups. Electrophoretic analysis of the isoenzymes PGM, GP1, ALAT and AS AT failed to show any difference between parasite strains isolated from treated and untreated mice, which indicates that no detectable clonal selection or parasite genetic markers alterations concerning the isoenzymes analysed have been determined by treatment with drugs of recognized antiparasitic effect, suggesting stability of the phenotypic characteristics of the three biological types of T. cruzi strains.Com o objetivo de investigar a influência da quimioterapia no padrão bioquímico de diferentes cepas do Trypanosoma cruzi, três grupos de camundongos foram infectados respectivamente com as cepas Peruana, 21 SF e Colombiana, que correspondem a diferentes padrões biológicos e isoenzimáticos. Cada grupo foi subdividido em subgrupos: 1 - tratados com nifurtimox; 2 - tratados com benzonidazol; 3- controles infectados não tratados. Ao final do tratamento que durou 90 dias, os animais foram submetidos a testes parasitológicos de cura: xenodiagnóstico, subinoculação do sangue em camundongos recém-nascidos e hemocultura em meio Warren. A partir da positivação destes testes, foram isoladas 22 amostras do T. cruzi dos três subgrupos. A análise eletroforética dos extratos enzimáticos obtidos após cultura para as enzimas PGM, GPI, ALAT e

  1. Effect of biotherapy T. cruzi 7x in several therapeutic schemes on experimental infection by Trypanosoma cruzi

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    Angélica Sayuri Mizutani

    2011-09-01

    Full Text Available Background: Biotherapy is used against infectious diseases treatment and prophylaxis and has been investigated by many researchers [1,2]. Aim: Assess the effect of biotherapy 7x T. cruzi on several treatment schemes, upon experimental infection by T. cruzi. Methodology: A blind, controlled and randomized by drawing experiment was performed. Male Swiss mice, four weeks old were utilized. Groups evaluated: IC – Infection Control (treated with water – 9 animals; TBBA7x3days – Treated with biotherapy 7x 3 days before and 3 days after infection (5 animals; TBB7x3days – Treated with 7x biotherapy 3 days before infection (5 animals; TBBAI7x3days – Treated with 7x biotherapy 3 days before infection and after infection indefinitely (6 animals. Animals were inoculated intraperitoneally with 1400 blood trypomastigotes Y strain. Biotherapy: prepared according to Farmacopéia Homeopática Brasileira [3]. Treatment plan: offered ad libitum, in the water (10µL/mL. Parasitological parameters: parasitemia was assessed according Brener’s technique. [4]. Clinical parameters: body hair aspect, edema, movement, diarrhea, body weight, temperature, food and water intake. Ethics: Registration 030/2008 UEM Ethics Committee for Experiments in Animals. Statistical analysis: was performed using the tests Kruskal Wallis and Mann-Whitney testes, significance 5%. Results: The best effect obtained was with the TBBA7x3days, both for clinical and parasitological parameters. It was expressed by lower parasitemia curve (p=0.04 and decrease of patent period tendency, of total parasitemia, of mortality and survival of the animals increase (Table 1. Evolution of parasitemia was distinct for the several treatment schemes. Survival of at least one mouse by treated groups is an extremely important data, since Y strain causes 100% mortality in Swiss mice

  2. Mammalian cell invasion and intracellular trafficking by Trypanosoma cruzi infective forms

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    Renato A. Mortara

    2005-03-01

    Full Text Available Trypanosoma cruzi, the etiological agent of Chagas’ disease, occurs as different strains or isolates that may be grouped in two major phylogenetic lineages: T. cruzi I, associated with the sylvatic cycle and T. cruzi II, linked to the human disease. In the mammalian host the parasite has to invade cells and many studies implicated the flagellated trypomastigotes in this process. Several parasite surface components and some of host cell receptors with which they interact have been identified. Our work focused on how amastigotes, usually found growing in the cytoplasm, can invade mammalian cells with infectivities comparable to that of trypomastigotes. We found differences in cellular responses induced by amastigotes and trypomastigotes regarding cytoskeletal components and actin-rich projections. Extracellularly generated amastigotes of T. cruzi I strains may display greater infectivity than metacyclic trypomastigotes towards cultured cell lines as well as target cells that have modified expression of different classes of cellular components. Cultured host cells harboring the bacterium Coxiella burnetii allowed us to gain new insights into the trafficking properties of the different infective forms of T. cruzi, disclosing unexpected requirements for the parasite to transit between the parasitophorous vacuole to its final destination in the host cell cytoplasm.O agente etiológico da doença de Chagas, Trypanosoma cruzi, ocorre como cepas ou isolados que podem ser agrupados em duas grandes linhagens filogenéticas: T. cruzi I associada ao ciclo silvestre e T. cruzi II ligada à doençahumana. No hospedeiro mamífero o parasita tem que invadir células, e vários estudos relacionam as formas flageladas tripomastigotas neste processo. Diferentes componentes de superfície dos parasitas e alguns dos respectivos receptores foram identificados. Em nosso trabalho temos procurado compreender como amastigotas, que normalmente são encontrados crescendo

  3. TNF/TNFR1 signaling up-regulates CCR5 expression by CD8+ T lymphocytes and promotes heart tissue damage during Trypanosoma cruzi infection: beneficial effects of TNF-α blockade

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    Karina Kroll-Palhares

    2008-06-01

    Full Text Available In Chagas disease, understanding how the immune response controls parasite growth but also leads to heart damage may provide insight into the design of new therapeutic strategies. Tumor necrosis factor-alpha (TNF-α is important for resistance to acute Trypanosoma cruzi infection; however, in patients suffering from chronic T. cruzi infection, plasma TNF-α levels correlate with cardiomyopathy. Recent data suggest that CD8-enriched chagasic myocarditis formation involves CCR1/CCR5-mediated cell migration. Herein, the contribution of TNF-α, especially signaling through the receptor TNFR1/p55, to the pathophysiology of T. cruzi infection was evaluated with a focus on the development of myocarditis and heart dysfunction. Colombian strain-infected C57BL/6 mice had increased frequencies of TNFR1/p55+ and TNF-α+ splenocytes. Although TNFR1-/- mice exhibited reduced myocarditis in the absence of parasite burden, they succumbed to acute infection. Similar to C57BL/6 mice, Benznidazole-treated TNFR1-/- mice survived acute infection. In TNFR1-/- mice, reduced CD8-enriched myocarditis was associated with defective activation of CD44+CD62Llow/- and CCR5+ CD8+ lymphocytes. Also, anti-TNF-α treatment reduced the frequency of CD8+CCR5+ circulating cells and myocarditis, though parasite load was unaltered in infected C3H/HeJ mice. TNFR1-/- and anti-TNF-α-treated infected mice showed regular expression of connexin-43 and reduced fibronectin deposition, respectively. Furthermore, anti-TNF-α treatment resulted in lower levels of CK-MB, a cardiomyocyte lesion marker. Our results suggest that TNF/TNFR1 signaling promotes CD8-enriched myocarditis formation and heart tissue damage, implicating the TNF/TNFR1 signaling pathway as a potential therapeutic target for control of T. cruzi-elicited cardiomyopathy.

  4. TNF/TNFR1 signaling up-regulates CCR5 expression by CD8+ T lymphocytes and promotes heart tissue damage during Trypanosoma cruzi infection: beneficial effects of TNF-alpha blockade.

    Science.gov (United States)

    Kroll-Palhares, Karina; Silvério, Jaline Coutinho; Silva, Andrea Alice da; Michailowsky, Vladimir; Marino, Ana Paula; Silva, Neide Maria; Carvalho, Cristiano Marcelo Espinola; Pinto, Luzia Maria de Oliveira; Gazzinelli, Ricardo Tostes; Lannes-Vieira, Joseli

    2008-06-01

    In Chagas disease, understanding how the immune response controls parasite growth but also leads to heart damage may provide insight into the design of new therapeutic strategies. Tumor necrosis factor-alpha (TNF-alpha) is important for resistance to acute Trypanosoma cruzi infection; however, in patients suffering from chronic T. cruzi infection, plasma TNF-alpha levels correlate with cardiomyopathy. Recent data suggest that CD8-enriched chagasic myocarditis formation involves CCR1/CCR5-mediated cell migration. Herein, the contribution of TNF-alpha, especially signaling through the receptor TNFR1/p55, to the pathophysiology of T. cruzi infection was evaluated with a focus on the development of myocarditis and heart dysfunction. Colombian strain-infected C57BL/6 mice had increased frequencies of TNFR1/p55+ and TNF-alpha+ splenocytes. Although TNFR1-/- mice exhibited reduced myocarditis in the absence of parasite burden, they succumbed to acute infection. Similar to C57BL/6 mice, Benznidazole-treated TNFR1-/- mice survived acute infection. In TNFR1-/- mice, reduced CD8-enriched myocarditis was associated with defective activation of CD44+CD62Llow/- and CCR5+ CD8+ lymphocytes. Also, anti-TNF-alpha treatment reduced the frequency of CD8+CCR5+ circulating cells and myocarditis, though parasite load was unaltered in infected C3H/HeJ mice. TNFR1-/- and anti-TNF-alpha-treated infected mice showed regular expression of connexin-43 and reduced fibronectin deposition, respectively. Furthermore, anti-TNF-alpha treatment resulted in lower levels of CK-MB, a cardiomyocyte lesion marker. Our results suggest that TNF/TNFR1 signaling promotes CD8-enriched myocarditis formation and heart tissue damage, implicating the TNF/TNFR1 signaling pathway as a potential therapeutic target for control of T. cruzi-elicited cardiomyopathy.

  5. Sarcocystis cruzi (Apicomplexa: Sarcocystidae no cachorro-do-mato (Cerdocyon thous Sarcocystis cruzi (Apicomplexa: Sarcocystidae in the crab-eating fox (Cerdocyon thous

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    Janaina S. Rodrigues

    2008-11-01

    Full Text Available Esporocistos de Sarcocystis foram identificados nas amostras fecais de um cachorro-do-mato. Eles foram dados por via oral para um bezerro em aleitamento, sendo observados cistos com morfologia compatível com os de Sarcocystis cruzi na musculatura cardíaca e esquelética, três meses após a infecção. Musculatura cardíaca deste bezerro foi dada para um segundo cão doméstico livre de coccídios, que eliminou esporocistos compatíveis com os de Sarcocystis em suas fezes, tendo com períodos pré-patente e patente 11 e 12 dias após a infecção respectivamente. Para comparar a morfologia dos esporocistos e cistos, um segundo cão, também livre de coccídios, foi alimentado com musculatura cardíaca de um bovino infectando naturalmente e positivo para cistos de S. cruzi. Esporocistos compatíveis com os eliminados pelo primeiro cão foram encontrados nas fezes. Apesar dos esporocistos eliminados pelo cachorro-do-mato serem significativamente diferentes dos eliminados pelos cães infectados experimentalmente, pode se considerar com base na morfologia dos esporocistos, cistos e na transmissão biológica que a espécie encontrada nas fezes do cachorro-do-mato é Sarcocystis cruzi.Sporocysts of Sarcocystis were identified in feces samples of a crab-eating fox, and were orally given to a suckling calf; after 3 months of infection, sarcocysts morphologically similar to Sarcocystis cruzi were observed in cardiac and skeletal striated muscles. The cardiac muscles of this calf were orally given to a puppy free of coccidia, that shed sporocysts in its feces.with a prepatent and patent period of 11 and 12 days after infection, respectively. To compare the morphology of the sporocysts and cysts, a second puppy was fed on bovine cardiac muscles infected naturally, and sporocysts identical to those shed by the first dog were recovered from its feces. In spite of the significant difference between sporocysts found in the mucosa of the crab-eating fox and

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

    Science.gov (United States)

    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

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

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    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.

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

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    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

  9. Trypanosoma cruzi contains a single detectable uracil-DNA glycosylase and repairs uracil exclusively via short patch base excision repair

    DEFF Research Database (Denmark)

    Pena Diaz, Javier; Akbari, Mansour; Sundheim, Ottar;

    2004-01-01

    Enzymes involved in genomic maintenance of human parasites are attractive targets for parasite-specific drugs. The parasitic protozoan Trypanosoma cruzi contains at least two enzymes involved in the protection against potentially mutagenic uracil, a deoxyuridine triphosphate nucleotidohydrolase (...

  10. The importance of the opossum (Didelphis albiventris as a reservoir for Trypanosoma cruzi in Bambuí, Minas Gerais state

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    Alexandre José Fernandes

    1991-03-01

    Full Text Available In a survey realized on the sylvatic and peridomestic environment at Bambuí county, Minas Gerais State, 44 (37.9% out of 116 opossums (Didelphis albiventris captured were found to be naturally infected with Trypanosoma cruzi. One handred and forty three parasite samples were obtanied from 43 infected opossums using simultaneously hemoculture, xenodiagnosis (Triatoma infestans, Panstrongylus megistus and Rhodnius neglectus and examination of anal glands contents. The parasite samples were characterized according to six isoenzyme patterns. All samples, independently of the method of isolation, presented an isoenzyme pattern similar to the standard T. cruzi Z1, showing that either xenodiagnosis or hemoculture can used without selecting parasite subpopulation from naturally infected opossums. Preveous isoenzyme patterns reported for human T.cruzi isolates from same region were completely different. This isoenzyme dissimilarity between sylvatic and domiciliar environments suggests the existence of two independent T. cruzi transmission cycles in Bambuí. The epidemiological implicatinos of these results are discussed.

  11. Short communication: Genetic variants of Sarcocystis cruzi in infected Malaysian cattle based on 18S rDNA.

    Science.gov (United States)

    Ng, Yit Han; Fong, Mun Yik; Subramaniam, Vellayan; Shahari, Shahhaziq; Lau, Yee Ling

    2015-12-01

    Sarcocystis species are pathogenic parasites that infect a wide range of animals, including cattle. A high prevalence of cattle sarcocystosis has been reported worldwide, but its status is unknown in Malaysia. This study focused on utilizing 18S rDNA to identify Sarcocystis species in Malaysian cattle and to determine their genetic variants. In this study, only Sarcocystis cruzi was detected in Malaysian cattle. The intra-species S. cruzi phylogenetic tree analysis and principal coordinate analysis (PCoA), respectively displayed two minor groups among the parasite isolates. This finding was supported by high Wright FST value (FST=0.647). The definitive hosts (dogs) may play a fundamental role in the development of S. cruzi genetic variants. Additionally, the existence of microheterogeneity within the S. cruzi merozoites and/or distinct genetic variants arisen from independent merozoites in mature sarcocysts, possibly contributed to the existence of intra-species variations within the population.

  12. The pentose phosphate pathway in Trypanosoma cruzi: a potential target for the chemotherapy of Chagas disease

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    Mariana Igoillo-Esteve

    2007-12-01

    Full Text Available Trypanosoma cruzi is highly sensitive to oxidative stress caused by reactive oxygen species. Trypanothione, the parasite's major protection against oxidative stress, is kept reduced by trypanothione reductase, using NADPH; the major source of the reduced coenzyme seems to be the pentose phosphate pathway. Its seven enzymes are present in the four major stages in the parasite's biological cycle; we have cloned and expressed them in Escherichia coli as active proteins. Glucose 6-phosphate dehydrogenase, which controls glucose flux through the pathway by its response to the NADP/NADPH ratio, is encoded by a number of genes per haploid genome, and is induced up to 46-fold by hydrogen peroxide in metacyclic trypomastigotes. The genes encoding 6-phosphogluconolactonase, 6-phosphogluconate dehydrogenase, transaldolase and transketolase are present in the CL Brener clone as a single copy per haploid genome. 6-phosphogluconate dehydrogenase is very unstable, but was stabilized introducing two salt bridges by site-directed mutagenesis. Ribose-5-phosphate isomerase belongs to Type B; genes encoding Type A enzymes, present in mammals, are absent. Ribulose-5-phosphate epimerase is encoded by two genes. The enzymes of the pathway have a major cytosolic component, although several of them have a secondary glycosomal localization, and also minor localizations in other organelles.Trypanosoma cruzi é altamente sensível ao estresse oxidativo causado por espécies reativas do oxigênio. Tripanotiona, o principal protetor do parasita contra o estresse oxidativo, é mantido reduzido pela tripanotiona redutase, pela presença deNADPH; a principal fonte da coenzima reduzida parece ser a via da pentose fosfato. As sete enzimas dessa via estão presentes nos quatro principais estágios do ciclo biológico do parasita; nós clonamos e expressamos as enzimas em Escherichia coli como proteínas ativas. Glucose 6-fosfato desidrogenase, que controla o fluxo da glucose da

  13. Prevalence and Transmission of Trypanosoma cruzi in People of Rural Communities of the High Jungle of Northern Peru.

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    Karen A Alroy

    2015-05-01

    Full Text Available Vector-borne transmission of Trypanosoma cruzi is seen exclusively in the Americas where an estimated 8 million people are infected with the parasite. Significant research in southern Peru has been conducted to understand T. cruzi infection and vector control, however, much less is known about the burden of infection and epidemiology in northern Peru.A cross-sectional study was conducted to estimate the seroprevalence of T. cruzi infection in humans (n=611 and domestic animals [dogs (n=106 and guinea pigs (n=206] in communities of Cutervo Province, Peru. Sampling and diagnostic strategies differed according to species. An entomological household study (n=208 was conducted to identify the triatomine burden and species composition, as well as the prevalence of T. cruzi in vectors. Electrocardiograms (EKG were performed on a subset of participants (n=90 T. cruzi infected participants and 170 age and sex-matched controls. The seroprevalence of T. cruzi among humans, dogs, and guinea pigs was 14.9% (95% CI: 12.2-18.0%, 19.8% (95% CI: 12.7-28.7% and 3.3% (95% CI: 1.4-6.9% respectively. In one community, the prevalence of T. cruzi infection was 17.2% (95% CI: 9.6-24.7% among participants < 15 years, suggesting recent transmission. Increasing age, positive triatomines in a participant's house, and ownership of a T. cruzi positive guinea pig were independent correlates of T. cruzi infection. Only one species of triatomine was found, Panstrongylus lignarius, formerly P. herreri. Approximately forty percent (39.9%, 95% CI: 33.2-46.9% of surveyed households were infested with this vector and 14.9% (95% CI: 10.4-20.5% had at least one triatomine positive for T. cruzi. The cardiac abnormality of right bundle branch block was rare, but only identified in seropositive individuals.Our research documents a substantial prevalence of T. cruzi infection in Cutervo and highlights a need for greater attention and vector control efforts in northern Peru.

  14. 4-Nitrobenzaldehyde thiosemicarbazone: a new compound derived from S-(-)-limonene that induces mitochondrial alterations in epimastigotes and trypomastigotes of Trypanosoma cruzi.

    Science.gov (United States)

    Britta, Elizandra Aparecida; Scariot, Débora Botura; Falzirolli, Hugo; da Silva, Cleuza Conceição; Ueda-Nakamura, Tânia; Dias Filho, Benedito Prado; Borsali, Redouane; Nakamura, Celso Vataru

    2015-06-01

    Trypanosoma cruzi is the causative agent of Chagas' disease, a parasitic disease that remains a serious health concern with unsatisfactory treatment. Drugs that are currently used to treat Chagas' disease are partially effective in the acute phase but ineffective in the chronic phase of the disease. The aim of the present study was to evaluate the antitrypanosomal activity and morphological, ultrastructural and biochemical alterations induced by a new molecule, 4-nitrobenzaldehyde thiosemicarbazone (BZTS), derived from S-(-)-limonene against epimastigote, trypomastigote and intracellular amastigote forms of T. cruzi. BZTS inhibited the growth of epimastigotes (IC50 = 9·2 μ m), intracellular amastigotes (IC50 = 3·23 μ m) and inhibited the viability of trypomastigotes (EC50 = 1·43 μ m). BZTS had a CC50 of 37·45 μ m in LLCMK2 cells. BZTS induced rounding and distortion of the cell body and severely damaged parasite mitochondria, reflected by extensive swelling and disorganization in the inner mitochondrial membrane and the presence of concentric membrane structures inside the organelle. Cytoplasmic vacuolization, endoplasmic reticulum that surrounded organelles, the loss of mitochondrial membrane potential, and increased mitochondrial O2 •- production were also observed. Our results suggest that BZTS alters the ultrastructure and physiology of mitochondria, which could be closely related to parasite death. PMID:25711881

  15. Combination of the essential oil constituents citral, eugenol and thymol enhance their inhibitory effect on Crithidia fasciculata and Trypanosoma cruzi growth

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    Camila M. O. Azeredo

    2013-10-01

    Full Text Available We analyzed the effect of the combination of citral, eugenol and thymol, respectively the main constituents of essential oils of Cympobogon citratus (DC Stapf, Poaceae (lemon grass, Syzygium aromaticum(L. Merr. & L.M. Perry, Myrtaceae (clove and Thymus vulgarisL., Lamiaceae (thyme, on the proliferation of the trypanosomatids Crithidia fasciculataand Trypanosoma cruzi.The constituents were initially added individually at different concentrations to C. fasciculatacultures to estimate the IC50/24h. Concentrations in a triple combination were about 2 times and 16.5 times lower against C. fasciculata and T. cruzi, respectively, as compared to isolated compounds. Incubation of C. fasciculatawith the trypanocydal agent benznidazole did not affect parasite growth at concentrations up to 500 µg/ml, but the IC50 of this drug against T. cruziwas 15.8 µg/ml, a value about 2-5 times higher than that of constituents in the triple combination. Analysis of treated C. fasciculata by scanning electron microscopy showed rounding of the cell body. Our data show that combination of essential oil constituents resulted in increased inhibitory activity on growth of both non-pathogenic and pathogenic trypanosomatid species and indicate that the non-patogenic C. fasciculata may represent a resistant model for drug screening in trypanosomatids.

  16. Structure of the Trypanosoma cruzi protein tyrosine phosphatase TcPTP1, a potential therapeutic target for Chagas' disease

    Energy Technology Data Exchange (ETDEWEB)

    Lountos, George T.; Tropea, Joseph E.; Waugh, David S. [FNL

    2013-06-05

    Chagas’ disease, a neglected tropical affliction transmitted by the flagellated protozoan Trypanosoma cruzi, is prevalent in Latin America and affects nearly 18 million people worldwide, yet few approved drugs are available to treat the disease. Moreover, the currently available drugs exhibit severe toxicity or are poorly effective in the chronic phase of the disease. This limitation, along with the large population at risk, underscores the urgent need to discover new molecular targets and novel therapeutic agents. Recently, the T. cruzi protein tyrosine phosphatase TcPTP1 has been implicated in the cellular differentiation and infectivity of the parasite and is therefore a promising target for the design of novel anti-parasitic drugs. Here, we report the X-ray crystal structure of TcPTP1 refined to a resolution of 2.18 Å, which provides structural insights into the active site environment that can be used to initiate structure-based drug design efforts to develop specific TcPTP1 inhibitors. Potential strategies to develop such inhibitors are also discussed.

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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. Seroprevalence of Trypanosoma cruzi among eleven potential reservoir species from six states across the southern United States.

    Science.gov (United States)

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

    2010-10-01

    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 (Arizona, California, Florida, Georgia, Missouri, and Virginia) were tested for antibodies to T. cruzi using indirect immunofluorescent antibody testing. In addition, culture isolation attempts were conducted on a limited number of animals from Georgia and Florida. Evidence of T. cruzi was found in every state except California; however, low numbers of known reservoirs were tested in California. In general, the highest seroprevalence rates were found in raccoons (0-68%) and opossums (17-52%), but antibodies to T. cruzi were also detected in small numbers of striped skunks (Mephitis mephitis) from Arizona and Georgia, bobcats (Lynx rufus) from Georgia, two coyotes (Canis latrans) from Georgia and Virginia, and a ringtail (Bassariscus astutus) from Arizona. Culture-based prevalence rates for raccoons were significantly greater than those for opossums; however, seroprevalences of raccoons and opossums from several geographic locations in Georgia and Florida were not different, indicating that exposure rates of these two species are similar within these areas. For both raccoons and opossums, seroprevalence was significantly higher in females than in males. No difference was detected in seroprevalence between adults and juveniles and between animals caught in urban and rural locations. Our results indicate that T. cruzi prevalence varies by host species, host characteristics, and geographic region and provides data to guide future studies on the natural history of T. cruzi in the

  1. Trypanosoma livingstonei: a new species from African bats supports the bat seeding hypothesis for the Trypanosoma cruzi clade

    OpenAIRE

    Lima, Luciana; Espinosa-Álvarez, Oneida; Hamilton, Patrick B; Neves, Luis; Takata, Carmen SA; Campaner, Marta; Attias, Márcia; De Souza, Wanderley; Camargo, Erney P.; Teixeira, Marta MG

    2013-01-01

    Background Bat trypanosomes have been implicated in the evolutionary history of the T. cruzi clade, which comprises species from a wide geographic and host range in South America, Africa and Europe, including bat-restricted species and the generalist agents of human American trypanosomosis T. cruzi and T. rangeli. Methods Trypanosomes from bats (Rhinolophus landeri and Hipposideros caffer) captured in Mozambique, southeast Africa, were isolated by hemoculture. Barcoding was carried out throug...

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

    OpenAIRE

    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...

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

    OpenAIRE

    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...

  4. Effect of tripanossomicide benznidazole (Rochagan) on the biodistribution of sodium pertechnetate (Na{sup 99m}TcO4) in Wistar rats

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, Vanessa Santos de Arruda; Holanda, Cecilia Maria de Carvalho Xavier; Silva, Roseane Pereira da; Medeiros, Aldo Cunha [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Ciencias da Saude]. E-mail: vambio@oi.com.br; Oliveira, Daniel Pereira de; Silva Junior, Mauricio Ferreira da; Oliveira, Elias Herculano de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Centro de Biociencias. Dept. de Microbiologia e Parasitologia; Spyrides, Maria Helena Constantino [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Dept. de Estatistica

    2008-12-15

    Benznidazole, a drug with specific anti-Trypanosoma cruzi activity, is used in the treatment of Chagas' disease. The radiopharmaceutical sodium pertechnetate (Na{sup 99m}TcO{sub 4}) is used to obtain diagnostic images of the stomach, thyroid, parathyroids, salivary glands, brain and in the study of esophageal reflux and blood flow. This study aimed at evaluating in vivo the influence of benznidazole treatment on the sodium pertechnetate biodistribution in Wistar rats. The percentage of radioactivity per gram (%ATI/g) of various organs (brain, heart, esophagus, stomach, small intestine, large intestine, spleen, liver, muscle and blood) was determined. Comparing the treated rats with the controls, we observed that sodium pertechnetate biodistribution did not change when administered to rats treated for thirty days with benznidazole. (author)

  5. Development of a Fluorescence-based Trypanosoma cruzi CYP51 Inhibition Assay for Effective Compound Triaging in Drug Discovery Programmes for Chagas Disease.

    OpenAIRE

    Jennifer Riley; Stephen Brand; Michael Voice; Ivan Caballero; David Calvo; Kevin D Read

    2015-01-01

    Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), is a life threatening global health problem with only two drugs available for treatment (benznidazole and nifurtimox), both having variable efficacy in the chronic stage of the disease and high rates of adverse drug reactions. Inhibitors of sterol 14α-demethylase (CYP51) have proven effective against T. cruzi in vitro and in vivo in animal models of Chagas disease. Consequently two azole inhibitors of CYP51 (posaco...

  6. Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil

    Directory of Open Access Journals (Sweden)

    Veruska Nogueira de Brito

    2014-11-01

    Full Text Available Visceral leishmaniasis (VL in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani. Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%, dog (3.30% and skunk (1.60%. We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.

  7. Phlebotomine fauna, natural infection rate and feeding habits of Lutzomyia cruzi in Jaciara, state of Mato Grosso, Brazil.

    Science.gov (United States)

    Brito, Veruska Nogueira de; Almeida, Arleana do Bom Parto Ferreira de; Nakazato, Luciano; Duarte, Rosemere; Souza, Cladson de Oliveira; Sousa, Valéria Régia Franco

    2014-11-01

    Visceral leishmaniasis (VL) in Brazil is transmitted by the phlebotomine Lutzomyia longipalpis and in some midwestern regions by Lutzomyia cruzi. Studies of the phlebotomine fauna, feeding habits and natural infection rate by Leishmania contribute to increased understanding of the epidemiological chain of leishmaniases and their vectorial capacity. Collections were performed in Jaciara, state of Mato Grosso from 2010-2013, during which time 2,011 phlebotomines (23 species) were captured (68.70% Lu. cruzi and 20.52% Lutzomyia whitmani). Lu. cruzi females were identified by observing the shapes of the cibarium (a portion of the mouthpart) and spermatheca, from which samples were obtained for polymerase chain reaction to determine the rates of natural infection. Engorged phlebotomines were assessed to identify the blood-meal host by ELISA. A moderate correlation was discovered between the number of Lu. cruzi and the temperature and the minimum rate of infection was 6.10%. Twenty-two females were reactive to the antisera of bird (28%), dog (3.30%) and skunk (1.60%). We conclude that Lu. cruzi and Lu. whitmani have adapted to the urban environment in this region and that Lu. cruzi is the most likely vector of VL in Jaciara. Moreover, maintenance of Leishmania in the environment is likely aided by the presence of birds and domestic and synanthropic animals.

  8. Ecological diversity of Trypanosoma cruzi transmission in the Amazon basin. The main scenaries in the Brazilian Amazon.

    Science.gov (United States)

    Coura, J R; Junqueira, A C V

    2015-11-01

    The ecological diversity of Trypanosoma cruzi transmission in the Brazilian Amazon region is directly interlinked with the parasite's extensive reservoir, composed of 33 species of wild mammals within the following orders: Marsupialia, Chiroptera, Rodentia, Xenarthra, Carnivora and Primates; and of 16 species of wild triatomines, of which ten may be infected with T. cruzi. Four scenarios for the diversity of T. cruzi transmission in the Brazilian Amazon region are evident: (i) T. cruzi transmission between vectors and wild mammals, which is characterized as a wild enzooty encompassing the entire Amazon basin; (ii) accidental T. cruzi transmission from vectors and wild mammals to humans, when they invade the wild ecotope or when these vectors and wild mammals invade human homes; (iii) occupational Chagas disease among piassava (Leopoldinia piassaba) palm fiber gatherers, transmitted by the vector Rhodnius brethesi, for which these palm trees are the specific ecotope; (IV) oral T. cruzi transmission to humans through food contamination, particularly in juices from plants such as assai, which today is considered to be endemic in the Brazilian Amazon region, with more than 1500 cases notified.

  9. Survey of Feral Swine ( Sus scrofa ) Infection with the Agent of Chagas Disease ( Trypanosoma cruzi ) in Texas, 2013-14.

    Science.gov (United States)

    Comeaux, Juliette M; Curtis-Robles, Rachel; Lewis, Barbara C; Cummings, Kevin J; Mesenbrink, Brian T; Leland, Bruce R; Bodenchuk, Michael J; Hamer, Sarah A

    2016-07-01

    : Feral swine ( Sus scrofa ) are an invasive species and reservoir of numerous zoonotic pathogens in the US, and Texas leads the nation in the estimated population size of feral hogs. Texas also harbors enzootic transmission cycles of the protozoan parasite Trypanosoma cruzi , agent of Chagas disease. Given previous evidence that swine can serve as reservoirs of T. cruzi in Latin America and new evidence of triatomines (kissing bugs) feeding on swine in Texas, we measured the prevalence of T. cruzi infection in feral swine in Texas. From 2013 to 2014, we sampled blood and/or cardiac tissue from 78 feral swine across 14 Texas counties (seven with and seven without prior documentation of kissing bug occurrence) and used PCR and histopathology to detect T. cruzi infection. We determined an overall infection prevalence of 6% (3 of 54) based on PCR evaluation of cardiac tissue, and no blood samples were positive (n=72). All three positive pigs were from counties where kissing bugs are documented. No T. cruzi amastigotes were noted on histopathology (n=54). Sarcocysts were observed in 10 (18%) of the samples, five of which also had mild focal areas of degeneration and inflammatory cell infiltration. Eco-epidemiologic investigations can provide an assessment of contributions of feral hogs to maintenance of T. cruzi across a landscape to help protect human and animal health.

  10. A new series of heteroleptic oxidovanadium(IV) compounds with phenanthroline-derived co-ligands: selective Trypanosoma cruzi growth inhibitors.

    Science.gov (United States)

    Fernández, Mariana; Varela, Javier; Correia, Isabel; Birriel, Estefanía; Castiglioni, Jorge; Moreno, Virtudes; Costa Pessoa, Joao; Cerecetto, Hugo; González, Mercedes; Gambino, Dinorah

    2013-09-01

    Searching for prospective metal-based drugs for the treatment of Chagas disease, a new series of ten mixed-ligand oxidovanadium(IV) complexes, [V(IV)O(L-2H)(NN)], where L is a tridentate salicylaldehyde semicarbazone derivative (L1-L5) and NN is either 5-amine-1,10-phenanthroline (aminophen) or 5,6-epoxy-5,6-dihydro-1,10-phenanthroline (epoxyphen), were synthesized. The compounds were characterized in the solid state and in solution. EPR spectroscopy suggests that the NN ligands act as bidentate through both nitrogen donor atoms in an axial-equatorial mode. The stability of the complexes in solution was investigated by EPR and (51)V-nuclear magnetic resonance spectroscopies. The complexes were evaluated in vitro for their activities against Trypanosoma cruzi (T. cruzi), the parasite responsible for the disease, and their selectivity was analyzed using J-774 murine macrophages, as a mammalian model. All the complexes are more active than both the reference drug Nifurtimox and the previously reported [V(IV)O(L-2H)(NN)] complexes. In general they are more active than the corresponding free NN ligands. Complexation led to highly increased selectivities towards the parasite. In addition, the lipophilicity of the compounds was determined and correlated with the observed activity in order to perform a QSAR (quantitative structure-activity relationship) study. A clear quadratic correlation is found. This study also confirms the influence of the structure of the co-ligand on the anti-T. cruzi effect. To get insight into the mechanism of action of the compounds, the changes in biochemical pathways promoted by two of the most active and most selective complexes are studied by analyzing a few of the parasite excreted metabolites by (1)H NMR spectroscopy. The combined information suggests that the mitochondrion could be a target for these complexes. Furthermore, DNA was preliminarily evaluated as a potential target by using atomic force microscopy (AFM), which showed that the

  11. In vitro screening of 2-(1H-imidazol-1-yl)-1-phenylethanol derivatives as antiprotozoal agents and docking studies on Trypanosoma cruzi CYP51.

    Science.gov (United States)

    De Vita, Daniela; Moraca, Francesca; Zamperini, Claudio; Pandolfi, Fabiana; Di Santo, Roberto; Matheeussen, An; Maes, Louis; Tortorella, Silvano; Scipione, Luigi

    2016-05-01

    Sterol 14α-demethylase (CYP51) is a key enzyme involved in the survival and virulence of many parasite protozoa, such as Trypanosoma and Leishmania species, thus representing a valuable drug target for the treatment of Kinetoplastid diseases. A set of azole-based compounds selected from an in-house compound library was in vitro screened against different human protozoan parasites. Several compounds showed selective activity against Trypanosoma cruzi, with compound 7 being the most active (IC50 = 40 nM). Given the structural similarity between the compounds here reported and known CYP51 inhibitors, a molecular docking study was performed to assess their binding with protozoal target and to rationalize the biological activity data. PMID:26922226

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

    Directory of Open Access Journals (Sweden)

    Gilberto Sánchez-González

    2016-03-01

    Full Text Available 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 in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico's national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years

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

    Science.gov (United States)

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

    2016-03-01

    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 in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico's national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years of Mexico's mandated

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

    Science.gov (United States)

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

    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 in official Norms in 2012. Most recent regulatory changes and segmented blood services in Mexico may affect compliance of mandatory screening guidelines. The objective of this study was to calculate the incremental cost-effectiveness ratio for total compliance of current guidelines from both Mexican primary healthcare and regular salaried worker health service institutions: the Secretary of Health and the Mexican Institute for Social Security. We developed a bi-modular model to analyze compliance using a decision tree for the most common screening algorithms for each health institution, and a Markov transition model for the natural history of illness and care. The incremental cost effectiveness ratio based on life-years gained is US$ 383 for the Secretary of Health, while the cost for an additional life-year gained is US$ 463 for the Social Security Institute. The results of the present study suggest that due to incomplete compliance of Mexico’s national legislation during 2013 and 2014, the MoH has failed to confirm 15,162 T. cruzi infections, has not prevented 2,347 avoidable infections, and has lost 333,483 life-years. Although there is a vast difference in T. cruzi prevalence between Bolivia and Mexico, Bolivia established mandatory blood screening for T.cruzi in 1996 and until 2002 detected and discarded 11,489 T. cruzi -infected blood units and prevented 2,879 potential infections with their transfusion blood screening program. In the first two years of Mexico

  15. Antiprotozoal and cytotoxic activities in vitro of Colombian Annonaceae.

    Science.gov (United States)

    Osorio, Edison; Arango, Gabriel Jaime; Jiménez, Nora; Alzate, Fernando; Ruiz, Grace; Gutiérrez, David; Paco, Marco Antonio; Giménez, Alberto; Robledo, Sara

    2007-05-22

    Ethnobotanical and chemotaxonomical studies for antiparasitic activity of Colombian Annonaceae were carried out. In vitro antiprotozoal activity of 36 extracts obtained from six different species was determined against promastigotes of three Leishmania species, epimastigotes of Trypanosoma cruzi and both chloroquine sensitive (F32) and resistant (W2) Plasmodium falciparum. Cytotoxic activity was evaluated in U-937 cells. Active extracts were selected according their selectivity index (SI). Extracts from Annona muricata, Rollinia exsucca, Rollinia pittieri and Xylopia aromatica were active against Leishmania spp. and Trypanosoma cruzi showing IC50 values lower than 25 microg/ml. Hexane extract from Rollinia pittieri leaves was the most selective against Trypanosoma cruzi and Leishmania spp. (IS=10 and 16, respectively). The extracts from Desmopsis panamensis, Pseudomalmea boyacana, Rollinia exsucca and Rollinia pittieri showed good antiplasmodial activity (IC50 Annonaceae extracts. Results presented here also demonstrate which plants and/or plant parts could be useful in the treatment of leishmaniasis, Chagas' disease and malaria.

  16. Experimental and Mathematical-Modeling Characterization of Trypanosoma cruzi Epimastigote Motility

    Science.gov (United States)

    Arias-del-Angel, Jorge A.; Dévora-Canales, Diego; Manning-Cela, Rebeca G.; Santana-Solano, Jesús; Santillán, Moisés

    2015-01-01

    The present work is aimed at characterizing the motility of parasite T. cruzi in its epimastigote form. To that end, we recorded the trajectories of two strains of this parasite (a wild-type strain and a stable transfected strain, which contains an ectopic copy of LYT1 gene and whose motility is known to be affected). We further extracted parasite trajectories from the recorded videos, and statistically analysed the following trajectory-step features: step length, angular change of direction, longitudinal and transverse displacements with respect to the previous step, and mean square displacement. Based on the resulting observations, we developed a mathematical model to simulate parasite trajectories. The fact that the model predictions closely match most of the experimentally observed parasite-trajectory characteristics, allows us to conclude that the model is an accurate description of T. cruzi motility. PMID:26544863

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Proteomic analysis of Trypanosoma cruzi developmental stages using isotope-coded affinity tag reagents.

    Science.gov (United States)

    Paba, Jaime; Ricart, Carlos A O; Fontes, Wagner; Santana, Jaime M; Teixeira, Antonio R L; Marchese, Jason; Williamson, Brian; Hunt, Tony; Karger, Barry L; Sousa, Marcelo V

    2004-01-01

    Comparative proteome analysis of developmental stages of the human pathogen Trypanosoma cruzi was carried out by isotope-coded affinity tag technology (ICAT) associated with liquid cromatography-mass spectrometry peptide sequencing (LC-MS/MS). Protein extracts of the protozoan trypomastigote and amastigote stages were labeled with heavy (D8) and light (D0) ICAT reagents and subjected to cation exchange and avidin affinity chromatographies followed by LC-MS/MS analysis. High confidence sequence information and expression levels for 41 T. cruzi polypeptides, including metabolic enzymes, paraflagellar rod components, tubulins, and heat-shock proteins were reported. Twenty-nine proteins displayed similar levels of expression in both forms of the parasite, nine proteins presented higher levels in trypomastigotes, whereas three were more expressed in amastigotes. PMID:15253433

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

    DEFF Research Database (Denmark)

    Queiroz, Rayner M L; Charneau, Sébastien; Bastos, Izabela M D;

    2014-01-01

    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...... in the PM subproteomes, including enzymes that might be suitable candidates for drug intervention. The comparison of the cell surface proteome among the life forms revealed some potentially stage-specific enzymes, although the majority was shared by both stages. Bioinformatic analysis showed that the vast......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...

  20. Response to chemotherapy with benznidazole of clones isolated from the 21SF strain of Trypanosoma cruzi (biodeme Type II, Trypanosoma cruzi II Resposta à quimioterapia com benzonidazol de clones isolados da cepa 21SF do Trypanosoma cruzi (biodema Tipo II, Trypanosoma cruzi II

    Directory of Open Access Journals (Sweden)

    Rozália Figueira Campos

    2005-04-01

    Full Text Available Susceptibility to chemotherapy with benznidazole was investigated of 5 clones isolated from the 21 SF strain (biodeme Type II, Trypanosoma cruzi II. Swiss mice were infected with the parental strain for each clone and submitted to chemotherapy with benznidazole (100mg/kg/day during 90 days. Treatment determined negativity of the parasitemia. Cure rates were evaluated by parasitological cure tests. Serology was evaluated for treated animals (titers from negative to 1:640 and untreated controls (1:160 to 1:640. Cure rates varied from 30 to 100% for the 5 clones, and were 25% for the parental strain. Results suggested that the variability of response to treatment of the clonal populations of Trypanosoma cruzi II strains is responsible for the high variation in the response to chemotherapy with benznidazole and nifurtimox by strains of this biodeme.A suscetibilidade à quimioterapia com o benzonidazol, de 5 clones isolados da cepa 21SF (biodema Tipo II, T. cruzi II, foi investigada. Camundongos suíços foram infectados com a cepa parental e com cada clone e submetidos à quimioterapia com benzonidazol (100mg/k/dia durante 90 dias. Os índices de cura foram avaliados pelos testes de cura parasitológicos. A sorologia foi avaliada para os animais tratados e (de negativo a 1: 640 e para os controles não tratados( 1:160 a 1:640. Os índices de cura variaram de 30% a 100% para os 5 clones sendo de 25% para a cepa parental. Os resultados sugerem que a variabilidade de resposta ao tratamento das populações clonais das cepas Trypanosoma cruzi II é responsável pela grande variação na resposta à quimioterapia com benzonidazol e nifurtimox das cepas deste biodema.

  1. La enfermedad del adyuvante en ratas infectadas experimentalmente con Trypanosoma cruzi

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    Silvia Revelli

    1986-06-01

    Full Text Available Se estudió la evolución de la artritis por adyuvante en ratas que habían sido infectadas previamente con Trypanosoma cruzi, con el objeto de evaluar su competencia inmunológica a través de la respuesta artrítica. La artritis por adyuvante se indujo en ratas adultas, endocriadas de ambos sexos, con 0.1 mi de adyuvante completo de Freund en la almohadilla plantar, en 2 lotes: a inyectadas 90 días antes con 1 x 10(6 T. cruzi y b testigos normales simultáneos. Se midieron, la lesión artrítica macroscópicamente con una escala semicuantitativa, y con microscopía óptica la histopatología de la lesión local y la del corazón, a los 180 días post-infecoión. La magnitud de las lesiones artríticas en las ratas con T. cruzi fue significativamente menor (p < 0.001 que la de los testigos, en todo el período. El infiltrado inflamatorio local, formado por linfocitos, plasmocitos y macrófagos fue significativamente menor (p < 0.001 en las ratas chagásicas, con respecto al de los testigos. Se postula que en las ratas que recibieron T. cruzi la respuesta artrítica menor podría deberse a una competición antigénica con los determinantes del parásito o a mecanismos inmunosupresores que interfieren en la producción de la entidad experimental.

  2. Frequent house invasion of Trypanosoma cruzi-infected triatomines in a suburban area of Brazil.

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    Gilmar Ribeiro

    2015-04-01

    Full Text Available The demographic transition of populations from rural areas to large urban centers often results in a disordered occupation of forest remnants and increased economic pressure to develop high-income buildings in these areas. Ecological and socioeconomic factors associated with these urban transitions create conditions for the potential transmission of infectious diseases, which was demonstrated for Chagas disease.We analyzed 930 triatomines, mainly Triatoma tibiamaculata, collected in artificial and sylvatic environments (forests near houses of a suburban area of the city of Salvador, Bahia State, Brazil between 2007 and 2011. Most triatomines were captured at peridomiciles. Adult bugs predominated in all studied environments, and nymphs were scarce inside houses. Molecular analyses of a randomly selected sub-sample (n=212 of triatomines showed Trypanosoma cruzi infection rates of 65%, 50% and 56% in intradomestic, peridomestic and sylvatic environments, respectively. We detected the T. cruzi lineages I and II and mixed infections. We also showed that T. tibiamaculata fed on blood from birds (50%, marsupials (38%, ruminants (7% and rodents (5%. The probability of T. cruzi infection was higher in triatomines that fed on marsupial blood (odds ratio (OR = 1.95, 95% confidence interval (CI = 1.22-3.11. Moreover, we observed a protective effect against infection in bugs that fed on bird blood (OR = 0.43, 95% CI = 0.30-0.73.The frequent invasion of houses by infected triatomines indicates a potential risk of T. cruzi transmission to inhabitants in this area. Our results reinforce that continuous epidemiological surveillance should be performed in areas where domestic transmission is controlled but enzootic transmission persists.

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

    OpenAIRE

    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...

  4. Ecological connectivity of Trypanosoma cruzi reservoirs and Triatoma pallidipennis hosts in an anthropogenic landscape with endemic Chagas disease.

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    Janine M Ramsey

    Full Text Available Traditional methods for Chagas disease prevention are targeted at domestic vector reduction, as well as control of transfusion and maternal-fetal transmission. Population connectivity of Trypanosoma cruzi-infected vectors and hosts, among sylvatic, ecotone and domestic habitats could jeopardize targeted efforts to reduce human exposure. This connectivity was evaluated in a Mexican community with reports of high vector infestation, human infection, and Chagas disease, surrounded by agricultural and natural areas. We surveyed bats, rodents, and triatomines in dry and rainy seasons in three adjacent habitats (domestic, ecotone, sylvatic, and measured T. cruzi prevalence, and host feeding sources of triatomines. Of 12 bat and 7 rodent species, no bat tested positive for T. cruzi, but all rodent species tested positive in at least one season or habitat. Highest T. cruzi infection prevalence was found in the rodents, Baiomys musculus and Neotoma mexicana. In general, parasite prevalence was not related to habitat or season, although the sylvatic habitat had higher infection prevalence than by chance, during the dry season. Wild and domestic mammals were identified as bloodmeals of T. pallidipennis, with 9% of individuals having mixed human (4.8% single human and other mammal species in bloodmeals, especially in the dry season; these vectors tested >50% positive for T. cruzi. Overall, ecological connectivity is broad across this matrix, based on high rodent community similarity, vector and T. cruzi presence. Cost-effective T. cruzi, vector control strategies and Chagas disease transmission prevention will need to consider continuous potential for parasite movement over the entire landscape. This study provides clear evidence that these strategies will need to include reservoir/host species in at least ecotones, in addition to domestic habitats.

  5. Automated high-content assay for compounds selectively toxic to Trypanosoma cruzi in a myoblastic cell line.

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    Julio Alonso-Padilla

    2015-01-01

    Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, represents a very important public health problem in Latin America where it is endemic. Although mostly asymptomatic at its initial stage, after the disease becomes chronic, about a third of the infected patients progress to a potentially fatal outcome due to severe damage of heart and gut tissues. There is an urgent need for new drugs against Chagas disease since there are only two drugs available, benznidazole and nifurtimox, and both show toxic side effects and variable efficacy against the chronic stage of the disease.Genetically engineered parasitic strains are used for high throughput screening (HTS of large chemical collections in the search for new anti-parasitic compounds. These assays, although successful, are limited to reporter transgenic parasites and do not cover the wide T. cruzi genetic background. With the aim to contribute to the early drug discovery process against Chagas disease we have developed an automated image-based 384-well plate HTS assay for T. cruzi amastigote replication in a rat myoblast host cell line. An image analysis script was designed to inform on three outputs: total number of host cells, ratio of T. cruzi amastigotes per cell and percentage of infected cells, which respectively provides one host cell toxicity and two T. cruzi toxicity readouts. The assay was statistically robust (Z´ values >0.6 and was validated against a series of known anti-trypanosomatid drugs.We have established a highly reproducible, high content HTS assay for screening of chemical compounds against T. cruzi infection of myoblasts that is amenable for use with any T. cruzi strain capable of in vitro infection. Our visual assay informs on both anti-parasitic and host cell toxicity readouts in a single experiment, allowing the direct identification of compounds selectively targeted to the parasite.

  6. Automated High-Content Assay for Compounds Selectively Toxic to Trypanosoma cruzi in a Myoblastic Cell Line

    Science.gov (United States)

    Alonso-Padilla, Julio; Cotillo, Ignacio; Presa, Jesús L.; Cantizani, Juan; Peña, Imanol; Bardera, Ana I.; Martín, Jose J.; Rodriguez, Ana

    2015-01-01

    Background Chagas disease, caused by the protozoan parasite Trypanosoma cruzi, represents a very important public health problem in Latin America where it is endemic. Although mostly asymptomatic at its initial stage, after the disease becomes chronic, about a third of the infected patients progress to a potentially fatal outcome due to severe damage of heart and gut tissues. There is an urgent need for new drugs against Chagas disease since there are only two drugs available, benznidazole and nifurtimox, and both show toxic side effects and variable efficacy against the chronic stage of the disease. Methodology/Principal Findings Genetically engineered parasitic strains are used for high throughput screening (HTS) of large chemical collections in the search for new anti-parasitic compounds. These assays, although successful, are limited to reporter transgenic parasites and do not cover the wide T. cruzi genetic background. With the aim to contribute to the early drug discovery process against Chagas disease we have developed an automated image-based 384-well plate HTS assay for T. cruzi amastigote replication in a rat myoblast host cell line. An image analysis script was designed to inform on three outputs: total number of host cells, ratio of T. cruzi amastigotes per cell and percentage of infected cells, which respectively provides one host cell toxicity and two T. cruzi toxicity readouts. The assay was statistically robust (Z´ values >0.6) and was validated against a series of known anti-trypanosomatid drugs. Conclusions/Significance We have established a highly reproducible, high content HTS assay for screening of chemical compounds against T. cruzi infection of myoblasts that is amenable for use with any T. cruzi strain capable of in vitro infection. Our visual assay informs on both anti-parasitic and host cell toxicity readouts in a single experiment, allowing the direct identification of compounds selectively targeted to the parasite. PMID:25615687

  7. Trypanosoma cruzi: an in vitro cycle of cell differentiation in axenic culture.

    Science.gov (United States)

    Rondinelli, E; Silva, R; Carvalho, J F; de Almeida Soares, C M; de Carvalho, E F; de Castro, F T

    1988-08-01

    The operation of an in vitro cycle of cell differentiation of Trypanosoma cruzi in axenic culture was obtained. When epimastigote forms, grown in LIT medium, were transferred to a modified LIT medium (E. Chiari, 1981, "Diferenciação do Trypanosoma cruzi em cultura." Ph.D. dissertation, Universidade Federal de Minas Gerais, Brazil), metacyclic trypomastigotes were generated. The latter, upon treatment with fresh human serum, and subsequent incubation in LIT medium gave origin to clusters of spheromastigote cells. The spheromastigotes were resistent to lysis mediated by the complement system and possess a morphology shown by optical and electron microscopy to be very similar to spheromastigotes derived from tissues of infected vertebrates. Blood-like trypomastigotes, or epimastigotes, could be obtained from spheromastigotes depending on the incubation conditions: at high serum concentration (55%) at 37 C, blood-like trypomastigotes were generated; by aging or heating (37 C), at low serum concentration (10%), epimastigotes were formed, closing the whole sequence of cell differentiation of T. cruzi. The molecular characterization of the different cell forms by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of metabolic pulse labeled proteins showed that the in vitro differentiated cells were distinct, not only by morphological criteria, but by differential gene expression as well. All the forms described could be obtained in large amounts (6 x 10(7) to 1 x 10(8)/ml), making it possible to perform preparative biochemical, molecular biological, and immunological experiments.

  8. The Dialogue of the Host-Parasite Relationship: Leishmania spp. and Trypanosoma cruzi Infection

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    Carlos Gustavo Vieira de Morais

    2015-01-01

    Full Text Available The intracellular protozoa Leishmania spp. and Trypanosoma cruzi and the causative agents of Leishmaniasis and Chagas disease, respectively, belong to the Trypanosomatidae family. Together, these two neglected tropical diseases affect approximately 25 million people worldwide. Whether the host can control the infection or develops disease depends on the complex interaction between parasite and host. Parasite surface and secreted molecules are involved in triggering specific signaling pathways essential for parasite entry and intracellular survival. The recognition of the parasite antigens by host immune cells generates a specific immune response. Leishmania spp. and T. cruzi have a multifaceted repertoire of strategies to evade or subvert the immune system by interfering with a range of signal transduction pathways in host cells, which causes the inhibition of the protective response and contributes to their persistence in the host. The current therapeutic strategies in leishmaniasis and trypanosomiasis are very limited. Efficacy is variable, toxicity is high, and the emergence of resistance is increasingly common. In this review, we discuss the molecular basis of the host-parasite interaction of Leishmania and Trypanosoma cruzi infection and their mechanisms of subverting the immune response and how this knowledge can be used as a tool for the development of new drugs.

  9. Experimental transmission of Trypanosoma cruzi through the genitalia of albino mice

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    Herrera Leidi

    2001-01-01

    Full Text Available Trypanosoma cruzi is usually transmitted by contact with the excreta of infected Triatominae; among non-vectorial infections, direct transmission through coitus has been proposed. We investigated this possibility by instilling, through the external meatus of the vagina and the penis of previously anesthetized NMRI albino mice, blood of mice infected with strains isolated from Didelphis marsupialis (opossum, strain CO57, Rattus rattus (rat, strain CO22 and human (strain EP. Some animals were allowed to copulate the same day of the instillation. In other experiments, the strains were inoculated in the scrotum. To determine the effect of immunosuppression, some mice were treated with cyclophosphamide 30 days post-instillation. Controls were instilled orally and ocularly. Vaginal instillation with strain CO22 produced systemic infection with tropism to the heart, skeletal muscle, skin, duodenum, pancreas, ovary and sternum. Scrotal inoculation with strain EP likewise invaded liver, spleen, lung, lymph nodes and urogenital organs; while strain CO57 invaded skeletal and cardiac muscle, pancreas, testis, and vas deferens. Penile infection with strain CO22 was detected by xenodiagnosis. Immunosuppression did not increase parasitemia of vaginally infected mice or controls. Mating did not produce infection. Our results show that contact of blood trypomastigotes of T. cruzi with genital mucosa can produce blood and tissue infections. These results are discussed in relation to reports of frequent experimental tropism of T. cruzi toward urogenital organs.

  10. Experimental transmission of Trypanosoma cruzi through the genitalia of albino mice.

    Science.gov (United States)

    Herrera, L; Urdaneta-Morales, S

    2001-07-01

    Trypanosoma cruzi is usually transmitted by contact with the excreta of infected Triatominae; among non-vectorial infections, direct transmission through coitus has been proposed. We investigated this possibility by instilling, through the external meatus of the vagina and the penis of previously anesthetized NMRI albino mice, blood of mice infected with strains isolated from Didelphis marsupialis (opossum, strain CO57), Rattus rattus (rat, strain CO22) and human (strain EP). Some animals were allowed to copulate the same day of the instillation. In other experiments, the strains were inoculated in the scrotum. To determine the effect of immunosuppression, some mice were treated with cyclophosphamide 30 days post-instillation. Controls were instilled orally and ocularly. Vaginal instillation with strain CO22 produced systemic infection with tropism to the heart, skeletal muscle, skin, duodenum, pancreas, ovary and sternum. Scrotal inoculation with strain EP likewise invaded liver, spleen, lung, lymph nodes and urogenital organs; while strain CO57 invaded skeletal and cardiac muscle, pancreas, testis, and vas deferens. Penile infection with strain CO22 was detected by xenodiagnosis. Immunosuppression did not increase parasitemia of vaginally infected mice or controls. Mating did not produce infection. Our results show that contact of blood trypomastigotes of T. cruzi with genital mucosa can produce blood and tissue infections. These results are discussed in relation to reports of frequent experimental tropism of T. cruzi toward urogenital organs. PMID:11500777

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

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    Cecilia Stahl Vieira

    2011-03-01

    Full Text Available Semiconductor nanoparticles, such as quantum dots (QDs, were used to carry out experiments in vivo and ex vivo with Trypanosoma cruzi. However, questions have been raised regarding the nanotoxicity of QDs in living cells, microorganisms, tissues and whole animals. The objective of this paper was to conduct a QD nanotoxicity study on living T. cruzi protozoa using analytical methods. This was accomplished using in vitro experiments to test the interference of the QDs on parasite development, morphology and viability. Our results show that after 72 h, a 200 μM cadmium telluride (CdTe QD solution induced important morphological alterations in T. cruzi, such as DNA damage, plasma membrane blebbing and mitochondrial swelling. Flow cytometry assays showed no damage to the plasma membrane when incubated with 200 μM CdTe QDs for up to 72 h (propidium iodide cells, giving no evidence of classical necrosis. Parasites incubated with 2 μM CdTe QDs still proliferated after seven days. In summary, a low concentration of CdTe QDs (2 μM is optimal for bioimaging, whereas a high concentration (200 μM CdTe could be toxic to cells. Taken together, our data indicate that 2 μM QD can be used for the successful long-term study of the parasite-vector interaction in real time.

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

    Science.gov (United States)

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

    2015-05-01

    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 epidemiological scenario in an endemic area in the province of Casanare. Insect vectors on Attalea butyracea palms were captured using both manual searches and bait traps. The capture of mammals was performed using Sherman and Tomahawk traps. We report an infestation index of 88.5% in 148 palms and an index of T. cruzi natural infection of 60.2% in 269 dissected insects and 11.9% in 160 captured mammals. High population densities of triatomines were observed in the sylvatic environment and there was a high relative abundance of reservoirs in the area, suggesting a stable enzootic cycle. We found no evidence of insect domiciliation. Taken together, these observations suggest that eco-epidemiological factors shape the transmission dynamics of T. cruzi, creating diverse scenarios of disease transmission.

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

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    Lina María Rendón

    2015-05-01

    Full Text Available 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 epidemiological scenario in an endemic area in the province of Casanare. Insect vectors on Attalea butyracea palms were captured using both manual searches and bait traps. The capture of mammals was performed using Sherman and Tomahawk traps. We report an infestation index of 88.5% in 148 palms and an index of T. cruzi natural infection of 60.2% in 269 dissected insects and 11.9% in 160 captured mammals. High population densities of triatomines were observed in the sylvatic environment and there was a high relative abundance of reservoirs in the area, suggesting a stable enzootic cycle. We found no evidence of insect domiciliation. Taken together, these observations suggest that eco-epidemiological factors shape the transmission dynamics of T. cruzi, creating diverse scenarios of disease transmission.

  14. The endless race between Trypanosoma cruzi and host immunity: lessons for and beyond Chagas disease.

    Science.gov (United States)

    Junqueira, Caroline; Caetano, Braulia; Bartholomeu, Daniella C; Melo, Mariane B; Ropert, Catherine; Rodrigues, Maurício M; Gazzinelli, Ricardo T

    2010-09-15

    Infection with the protozoan parasite Trypanosoma cruzi, the agent of Chagas disease, is characterised by a variable clinical course - from symptomless cases to severe chronic disease with cardiac and/or gastrointestinal involvement. The variability in disease outcome has been attributed to host responses as well as parasite heterogeneity. In this article, we review studies indicating the importance of immune responses as key determinants of host resistance to T. cruzi infection and the pathogenesis of Chagas disease. Particular attention is given to recent studies defining the role of cognate innate immune receptors and immunodominant CD8+ T cells that recognise parasite components - both crucial for host-parasite interaction and disease outcome. In light of these studies we speculate about parasite strategies that induce a strong and long-lasting T-cell-mediated immunity but at the same time allow persistence of the parasite in the vertebrate host. We also discuss what we have learned from these studies for increasing our understanding of Chagas pathogenesis and for the design of new strategies to prevent the development of Chagas disease. Finally, we highlight recent studies employing a genetically engineered attenuated T. cruzi strain as a vaccine shuttle that elicits potent T cell responses specific to a tumour antigen and protective immunity against a syngeneic melanoma cell line.

  15. The Dialogue of the Host-Parasite Relationship: Leishmania spp. and Trypanosoma cruzi Infection

    Science.gov (United States)

    de Morais, Carlos Gustavo Vieira; Castro Lima, Ana Karina; dos Santos, Rosiane Freire; Da-Silva, Silvia Amaral Gonçalves; Dutra, Patrícia Maria Lourenço

    2015-01-01

    The intracellular protozoa Leishmania spp. and Trypanosoma cruzi and the causative agents of Leishmaniasis and Chagas disease, respectively, belong to the Trypanosomatidae family. Together, these two neglected tropical diseases affect approximately 25 million people worldwide. Whether the host can control the infection or develops disease depends on the complex interaction between parasite and host. Parasite surface and secreted molecules are involved in triggering specific signaling pathways essential for parasite entry and intracellular survival. The recognition of the parasite antigens by host immune cells generates a specific immune response. Leishmania spp. and T. cruzi have a multifaceted repertoire of strategies to evade or subvert the immune system by interfering with a range of signal transduction pathways in host cells, which causes the inhibition of the protective response and contributes to their persistence in the host. The current therapeutic strategies in leishmaniasis and trypanosomiasis are very limited. Efficacy is variable, toxicity is high, and the emergence of resistance is increasingly common. In this review, we discuss the molecular basis of the host-parasite interaction of Leishmania and Trypanosoma cruzi infection and their mechanisms of subverting the immune response and how this knowledge can be used as a tool for the development of new drugs. PMID:26090399

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

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    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.

  17. Multi-epitope proteins for improved serological detection of Trypanosoma cruzi infection and Chagas Disease.

    Science.gov (United States)

    Duthie, Malcolm S; Guderian, Jeffery A; Vallur, Aarthy C; Misquith, Ayesha; Liang, Hong; Mohamath, Raodoh; Luquetti, Alejandro O; Carter, Darrick; Tavares, Suelene N B; Reed, Steven G

    2016-03-01

    We previously reported that tandem repeat (TR) proteins from Trypanosoma cruzi could serve as targets of the antibody response and be useful as diagnostic indicators. To optimize reagents for detecting T. cruzi infection we evaluated individual TR proteins and identified several that were recognized by the majority of Chagas patient's sera collected from individuals form Brazil. We then produced novel, recombinant fusion proteins to combine the reactive TR proteins into a single diagnostic product. Direct comparison of the antibody response of serum samples that were readily detected by the established fusion antigen used in commercial detection of Chagas disease, TcF, revealed strong responses to TcF43 and TcF26 proteins. While the TcF43 and TcF26 antigens enhanced detection and strength of signal, they did not compromise the specificity of detection compared to that obtained with TcF. Finally, it was apparent by testing against a panel of 84 serum samples assembled on the basis of moderate or weak reactivity against TcF (mostly signal:noise detected by many of the sera that had low TcF antibody levels. Taken together, these data indicate that TcF43 and TcF26 could be used to enhance the detection of T. cruzi infection as well as supporting a diagnosis of Chagas disease.

  18. The C-terminal region of Trypanosoma cruzi MASPs is antigenic and secreted via exovesicles

    Science.gov (United States)

    De Pablos, Luis Miguel; Díaz Lozano, Isabel María; Jercic, Maria Isabel; Quinzada, Markela; Giménez, Maria José; Calabuig, Eva; Espino, Ana Margarita; Schijman, Alejandro Gabriel; Zulantay, Inés; Apt, Werner; Osuna, Antonio

    2016-01-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, a neglected and emerging tropical disease, endemic to South America and present in non-endemic regions due to human migration. The MASP multigene family is specific to T. cruzi, accounting for 6% of the parasite’s genome and plays a key role in immune evasion. A common feature of MASPs is the presence of two conserved regions: an N-terminal region codifying for signal peptide and a C-terminal (C-term) region, which potentially acts as GPI-addition signal peptide. Our aim was the analysis of the presence of an immune response against the MASP C-term region. We found that this region is highly conserved, released via exovesicles (EVs) and has an associated immune response as revealed by epitope affinity mapping, IFA and inhibition of the complement lysis assays. We also demonstrate the presence of a fast IgM response in Balb/c mice infected with T. cruzi. Our results reveal the presence of non-canonical secreted peptides in EVs, which can subsequently be exposed to the immune system with a potential role in evading immune system targets in the parasite. PMID:27270330

  19. Trypanosoma cruzi strains isolated from human, vector, and animal reservoir in the same endemic region in Mexico and typed as T. cruzi I, discrete typing unit 1 exhibit considerable biological diversity

    Directory of Open Access Journals (Sweden)

    María del Carmen Sánchez-Guillén

    2006-09-01

    Full Text Available In this study, three strains of Trypanosoma cruzi were isolated at the same time and in the same endemic region in Mexico from a human patient with chronic chagasic cardiomyopathy (RyC-H; vector (Triatoma barberi (RyC-V; and rodent reservoir (Peromyscus peromyscus (RyC-R. The three strains were characterized by multilocus enzyme electrophoresis, random amplified polymorphic DNA, and by pathological profiles in experimental animals (biodemes. Based on the analysis of genetic markers the three parasite strains were typed as belonging to T. cruzi I major group, discrete typing unit 1. The pathological profile of RyC-H and RyC-V strains indicated medium virulence and low mortality and, accordingly, the strains should be considered as belonging to biodeme Type III. On the other hand, the parasites from RyC-R strain induced more severe inflammatory processes and high mortality (> 40% and were considered as belonging to biodeme Type II. The relationship between genotypes and biological characteristics in T. cruzi strains is still debated and not clearly understood. An expert committee recommended in 1999 that Biodeme Type III would correspond to T. cruzi I group, whereas Biodeme Type II, to T. cruzi II group. Our findings suggest that, at least for Mexican isolates, this correlation does not stand and that biological characteristics such as pathogenicity and virulence could be determined by factors different from those identified in the genotypic characterization

  20. Reaching for the Holy Grail: insights from infection/cure models on the prospects for vaccines for Trypanosoma cruzi infection

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    Juan Bustamante

    2015-05-01

    Full Text Available Prevention of Trypanosoma cruzi infection in mammals likely depends on either prevention of the invading trypomastigotes from infecting host cells or the rapid recognition and killing of the newly infected cells by T. cruzi-specific T cells. We show here that multiple rounds of infection and cure (by drug therapy fails to protect mice from reinfection, despite the generation of potent T cell responses. This disappointing result is similar to that obtained with many other vaccine protocols used in attempts to protect animals from T. cruzi infection. We have previously shown that immune recognition of T. cruzi infection is significantly delayed both at the systemic level and at the level of the infected host cell. The systemic delay appears to be the result of a stealth infection process that fails to trigger substantial innate recognition mechanisms while the delay at the cellular level is related to the immunodominance of highly variable gene family proteins, in particular those of the trans-sialidase family. Here we discuss how these previous studies and the new findings herein impact our thoughts on the potential of prophylactic vaccination to serve a productive role in the prevention of T. cruzi infection and Chagas disease.

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

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    C Miguel Pinto

    Full Text Available 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 parasites at species and genotype levels through phylogenetic approaches based on 18S ribosomal RNA (18S rRNA and cytochrome b (cytb genes and conducted a comparison of nucleotide diversity of the cytb gene. We document for the first time T. cruzi Tcbat and T. c. marinkellei in Ecuador, expanding their distribution in South America to the western side of the Andes. In addition, we found the triatomines Cavernicola pilosa and Triatoma dispar sharing shelters with bats. The comparisons of nucleotide diversity revealed a higher diversity for T. c. marinkellei than any of the T. c. cruzi genotypes associated with Chagas disease. Findings from this study increased both the number of host species and known geographical ranges of both parasites and suggest potential vectors for these two trypanosomes associated with bats in rural areas of southern Ecuador. The higher nucleotide diversity of T. c. marinkellei supports a long evolutionary relationship between T. cruzi and bats, implying that bats are the original hosts of this important parasite.

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

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    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.

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

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    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

  4. Bottlenecks in domestic animal populations can facilitate the emergence of Trypanosoma cruzi, the aetiological agent of Chagas disease

    Science.gov (United States)

    Levy, Michael Z.; Tustin, Aaron; Castillo-Neyra, Ricardo; Mabud, Tarub S.; Levy, Katelyn; Barbu, Corentin M.; Quispe-Machaca, Victor R.; Ancca-Juarez, Jenny; Borrini-Mayori, Katty; Naquira-Velarde, Cesar; Ostfeld, Richard S.

    2015-01-01

    Faeces-mediated transmission of Trypanosoma cruzi (the aetiological agent of Chagas disease) by triatomine insects is extremely inefficient. Still, the parasite emerges frequently, and has infected millions of people and domestic animals. We synthesize here the results of field and laboratory studies of T. cruzi transmission conducted in and around Arequipa, Peru. We document the repeated occurrence of large colonies of triatomine bugs (more than 1000) with very high infection prevalence (more than 85%). By inoculating guinea pigs, an important reservoir of T. cruzi in Peru, and feeding triatomine bugs on them weekly, we demonstrate that, while most animals quickly control parasitaemia, a subset of animals remains highly infectious to vectors for many months. However, we argue that the presence of these persistently infectious hosts is insufficient to explain the observed prevalence of T. cruzi in vector colonies. We posit that seasonal rains, leading to a fluctuation in the price of guinea pig food (alfalfa), leading to annual guinea pig roasts, leading to a concentration of vectors on a small subpopulation of animals maintained for reproduction, can propel T. cruzi through vector colonies and create a considerable force of infection for a pathogen whose transmission might otherwise fizzle out. PMID:26085582

  5. CCR5 plays a critical role in the development of myocarditis and host protection in mice infected with Trypanosoma cruzi.

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    Machado, Fabiana S; Koyama, Natalia S; Carregaro, Vanessa; Ferreira, Beatriz R; Milanezi, Cristiane M; Teixeira, Mauro M; Rossi, Marcos A; Silva, João S

    2005-02-15

    The pathogenesis of myocarditis during Trypanosoma cruzi infection is poorly understood. We investigated the role played by chemokine receptor 5 (CCR5) in the influx of T cells to the cardiac tissue of T. cruzi-infected mice. mRNA and protein for the CCR5 ligands CCL3, CCL4, and CCL5 were detected in the hearts of infected mice in association with CD4+ and CD8+ T cells. There was a high level of CCR5 expression on CD8+ T cells in the hearts of infected mice. Moreover, CCR5 expression on CD8+ T cells was positively modulated by T. cruzi infection. CCR5-deficient mice infected with T. cruzi experienced a dramatically inhibited migration of T cells to the heart and were also more susceptible to infection. These results suggest that CCR5 and its ligands play a central role in the control of T cell influx in T. cruzi-infected mice. Knowledge of the mechanisms that trigger and control the migration of cells to the heart in patients with Chagas disease may help in the design of drugs that prevent myocarditis and protect against the development of severe disease.

  6. Congenital transmission of Trypanosoma cruzi in central Brazil. A study of 1,211 individuals born to infected mothers.

    Science.gov (United States)

    Luquetti, Alejandro O; Tavares, Suelene Brito do Nascimento; Siriano, Liliane da Rocha; Oliveira, Rozângela Amaral de; Campos, Dayse Elizabeth; de Morais, Cicilio Alves; de Oliveira, Enio Chaves

    2015-05-01

    Transmission of Trypanosoma cruzi during pregnancy is estimated to occur in less than 20% of infected mothers; however, the etiopathogenesis is not completely understood. The Centre for Studies on Chagas Disease provides confirmation of T. cruzi infection for individuals living in central Brazil. In this retrospective hospital-based study, all requests for diagnosis of T. cruzi infection in individuals less than 21 years old from 1994-2014 were searched. We end with 1,211 individuals and their respective infected mothers. Congenital transmission of infection was confirmed in 24 individuals (2%) in central Brazil, an area where the main T. cruzi lineage circulating in humans is TcII. This low prevalence of congenital Chagas disease is discussed in relation to recent findings in the south region of Brazil, where TcV is the main lineage and congenital transmission has a higher prevalence (approximately 5%), similar to frequencies reported in Argentina, Paraguay and Bolivia. This is the first report to show geographical differences in the rates of congenital transmission of T. cruzi and the relationship between the prevalence of congenital transmission and the type of Tc prevalent in each region.

  7. Mitochondrial dysfunction in Trypanosoma cruzi: the role of Serratia marcescens prodigiosin in the alternative treatment of Chagas disease

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    Triana Omar

    2011-05-01

    Full Text Available Abstract Background Chagas disease is a health threat for many people, mostly those living in Latin America. One of the most important problems in treatment is the limitation of existing drugs. Prodigiosin, produced by Serratia marcescens (Rhodnius prolixus endosymbiont, belongs to the red-pigmented bacterial prodiginine family, which displays numerous biological activities, including antibacterial, antifungal, antiprotozoal, antimalarial, immunosuppressive, and anticancer properties. Here we describe its effects on Trypanosoma cruzi mitochondria belonging to Tc I and Tc II. Results Parasites exposed to prodigiosin altered the mitochondrial function and oxidative phosphorylation could not have a normal course, probably by inhibition of complex III. Prodigiosin did not produce cytotoxic effects in lymphocytes and Vero cells and has better effects than benznidazole. Our data suggest that the action of prodigiosin on the parasites is mediated by mitochondrial structural and functional disruptions that could lead the parasites to an apoptotic-like cell death process. Conclusions Here, we propose a potentially useful trypanocidal agent derived from knowledge of an important aspect of the natural life cycle of the parasite: the vector-parasite interaction. Our results indicate that prodigiosin could be a good candidate for the treatment of Chagas disease.

  8. Synthesis and trypanocidal activity of novel benzimidazole derivatives.

    Science.gov (United States)

    Velázquez-López, José Miguel; Hernández-Campos, Alicia; Yépez-Mulia, Lilián; Téllez-Valencia, Alfredo; Flores-Carrillo, Paulina; Nieto-Meneses, Rocío; Castillo, Rafael

    2016-09-01

    The present work reports the synthesis and biological activity of a series of 14 benzimidazole derivatives designed to act on the enzyme triosephosphate isomerase of Trypanosoma cruzi (TcTIM). This enzyme is involved in the metabolism of glucose, the only source of energy for the parasite. In this study, we found four compounds that inhibit TcTIM moderately and lack inhibitory activity against human TIM (HsTIM). In vitro studies against T. cruzi epimastigotes showed two compounds that were more active than the reference drug nifurtimox, and these presented a low cytotoxic effect in mouse macrophages (J744 cell line). PMID:27503677

  9. Cytokine-dependent and–independent gene expression changes and cell cycle block revealed in Trypanosoma cruzi-infected host cells by comparative mRNA profiling

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    Burleigh Barbara A

    2009-05-01

    Full Text Available Abstract Background The requirements for growth and survival of the intracellular pathogen Trypanosoma cruzi within mammalian host cells are poorly understood. Transcriptional profiling of the host cell response to infection serves as a rapid read-out for perturbation of host physiology that, in part, reflects adaptation to the infective process. Using Affymetrix oligonucleotide array analysis we identified common and disparate host cell responses triggered by T. cruzi infection of phenotypically diverse human cell types. Results We report significant changes in transcript abundance in T. cruzi-infected fibroblasts, endothelial cells and smooth muscle cells (2852, 2155 and 531 genes respectively; fold-change ≥ 2, p-value T. cruzi-infected fibroblasts and endothelial cells transwell plates were used to distinguish cytokine-dependent and -independent gene expression profiles. This approach revealed the induction of metabolic and signaling pathways involved in cell proliferation, amino acid catabolism and response to wounding as common themes in T. cruzi-infected cells. In addition, the downregulation of genes involved in mitotic cell cycle and cell division predicted that T. cruzi infection may impede host cell cycle progression. The observation of impaired cytokinesis in T. cruzi-infected cells, following nuclear replication, confirmed this prediction. Conclusion Metabolic pathways and cellular processes were identified as significantly altered at the transcriptional level in response to T. cruzi infection in a cytokine-independent manner. Several of these alterations are supported by previous studies of T. cruzi metabolic requirements or effects on the host. However, our methods also revealed a T. cruzi-dependent block in the host cell cycle, at the level of cytokinesis, previously unrecognized for this pathogen-host cell interaction.

  10. Saponins-rich fraction of Calotropis procera leaves elicit no antitrypanosomal activity in a rat model

    Institute of Scientific and Technical Information of China (English)

    Mohammed Auwal Ibrahim; Abubakar Babando Aliyu; Kayode Meduteni; Isa Yunusa

    2013-01-01

    Objective:To examine the in vitro and in vivo anti-Trypanosoma evansi (T. evansi ) activity of saponins-rich fraction of Calotropis procera (cpsf) leaves as well as the effect of the fraction on the parasite-induced anemia. Methods:A 60-minutes time course experiment was conducted with various concentrations of the fraction using a 96-well microtiter plate technique, and subsequently used to treat experimentally T. evansi infected rats at 100 and 200 mg/kg body weight. Index of anemia was analyzed in all animals during the experiment. Results:The cpsf did not demonstrate an in vitro antitrypanosomal activity. Further, the cpsf treatments did not significantly (P>0.05) keep the parasites lower than the infected untreated groups. At the end of the experiment, all T. evansi infected rats developed anemia whose severity was not significantly (P>0.05) ameliorated by the cpsf treatment. Conclusions:It was concluded that saponins derived from Calotropis procera leaves could not elicit in vitro and in vivo activities against T. evansi.

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

    Science.gov (United States)

    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

  12. Trypanosoma cruzi infection in the opossum Didelphis marsupialis: absence of neonatal transmission and protection by maternal antibodies in experimental infections

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    Ana M. Jansen

    1994-03-01

    Full Text Available The high rate of natural Trypanosoma cruzi infection found in opossums does not always correlate with appreciable densities of local triatomid populations. One alternative method which might bypass the invertebrate vector is direct transmission from mother to offspring. This possibility was investigated in five T. cruzi infected females and their litters (24 young. The influence of maternal antibodies transferred via lactation, on the course of experimental infection, was also examined. Our results show that neonatal transmission is probably not responsible for the high rate of natural T. cruzi infection among opossums. In addition antibodies of maternal origin confer a partial protection to the young. This was demonstrated by the finding of a double prepatency period and 4,5 fold lower levels of circulating parasites, in experimentally infected pouch young from infected as compared to control uninfected mothes. On the other hand, the duration of patent parasitemia was twice as long as that observed in the control group.

  13. Prevalencia de anticuerpos contra Trypanosoma cruzi en donadores de sangre del IMSS, Orizaba, Veracruz, México Prevalence of antibodies against Trypanossoma cruzi in blood bank donors from the IMSS General Hospital in Onizaba, Veracruz, Mexico

    OpenAIRE

    Angel Ramos-Ligonio; Michaía Elián Ramírez-Sánchez; Juan Carlos González-Hernández; José Luis Rosales-Encina; Aracely López-Monteon

    2006-01-01

    OBJETIVO: Determinar la prevalencia de anticuerpos contra Trypanosoma cruzi en donadores del Hospital General Regional del Instituto Mexicano del Seguro Social (IMSS) en la ciudad de Orizaba, Veracruz. MATERIAL Y MÉTODOS: Se examinaron muestras de donadores del banco de sangre del Hospital General Regional (HGRO) del IMSS para la búsqueda de antiT. cruzi por ELISA, Western blot e IFI, utilizando una proteína recombinante (MBP::Hsp70) y un extracto crudo de epimastigotes. Las muestras fueron o...

  14. Immunization with Hexon modified adenoviral vectors integrated with gp83 epitope provides protection against Trypanosoma cruzi infection.

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    Anitra L Farrow

    2014-08-01

    Full Text Available Trypanosoma cruzi is the causative agent of Chagas disease. Chagas disease is an endemic infection that affects over 8 million people throughout Latin America and now has become a global challenge. The current pharmacological treatment of patients is unsuccessful in most cases, highly toxic, and no vaccines are available. The results of inadequate treatment could lead to heart failure resulting in death. Therefore, a vaccine that elicits neutralizing antibodies mediated by cell-mediated immune responses and protection against Chagas disease is necessary.The "antigen capsid-incorporation" strategy is based upon the display of the T. cruzi epitope as an integral component of the adenovirus' capsid rather than an encoded transgene. This strategy is predicted to induce a robust humoral immune response to the presented antigen, similar to the response provoked by native Ad capsid proteins. The antigen chosen was T. cruzi gp83, a ligand that is used by T. cruzi to attach to host cells to initiate infection. The gp83 epitope, recognized by the neutralizing MAb 4A4, along with His6 were incorporated into the Ad serotype 5 (Ad5 vector to generate the vector Ad5-HVR1-gp83-18 (Ad5-gp83. This vector was evaluated by molecular and immunological analyses. Vectors were injected to elicit immune responses against gp83 in mouse models. Our findings indicate that mice immunized with the vector Ad5-gp83 and challenged with a lethal dose of T. cruzi trypomastigotes confer strong immunoprotection with significant reduction in parasitemia levels, increased survival rate and induction of neutralizing antibodies.This data demonstrates that immunization with adenovirus containing capsid-incorporated T. cruzi antigen elicits a significant anti-gp83-specific response in two different mouse models, and protection against T. cruzi infection by eliciting neutralizing antibodies mediated by cell-mediated immune responses, as evidenced by the production of several Ig isotypes

  15. Prevalencia de anticuerpos contra Trypanosoma cruzi en donadores de sangre del IMSS, Orizaba, Veracruz, México

    OpenAIRE

    Ramos-Ligonio Angel; Ramírez-Sánchez Michaía Elián; González-Hernández Juan Carlos; Rosales-Encina José Luis; López-Monteon Aracely

    2006-01-01

    OBJETIVO: Determinar la prevalencia de anticuerpos contra Trypanosoma cruzi en donadores del Hospital General Regional del Instituto Mexicano del Seguro Social (IMSS) en la ciudad de Orizaba, Veracruz. MATERIAL Y MÉTODOS: Se examinaron muestras de donadores del banco de sangre del Hospital General Regional (HGRO) del IMSS para la búsqueda de antiT. cruzi por ELISA, Western blot e IFI, utilizando una proteína recombinante (MBP::Hsp70) y un extracto crudo de epimastigotes. Las muestras fueron o...

  16. Fauna triatomenae do estado da Bahia, Brasil: VI - prevalência geográfica da infecção dos tratomíneos por T. cruzi

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    Ítalo A. Sherlock

    1974-06-01

    . conorhini but were not considered important as carriers of T. cruzi. The Authors consider that the presence of infected domiciliated bugs in the areas investigated implies active transmission of T. cruzi, and that vector control measures should be undertaken. The active spread of T. infestans in the State of Bahia is emphasized as a matter for particular concern, in view of this species susceptibility to infection, its anthropophilic habits and its capacity to colonize rapidly and stablish high rates of infestation.

  17. Prevalencia de infeccion humana por Trypanosoma cruzi en bancos de sangre en Venezuela Prevalence of human infections by Trypanosoma cruzi in Venezuelan blood banks

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    Alberto Aché

    1993-10-01

    Full Text Available Las primeras investigaciones realizadas a nivel de bancos de sangre, durante la década 50, indican que la seroprevalencia por infecciones a T. cruzi entre hemodadores fue de 12%. Un estudio posterior, entre 1963-64, efectuado en varios bancos de sangre, así como otros centros, registró una seroprevalencia global de 6.0% (1.1-10.1%. La donación de sangre en Venezuela es gratuita. El control de los bancos de sangre recae en el Departamento de Transfusiones y Bancos de Sangre del Ministerio de Sanidad y Asistencia Social. A partir de 1988, se emplea uniformemente la técnica de ELISA para el diagnóstico de infecciones a T. cruzi en los Bancos de Sangre. La seropositividad promedio interanual, entre 1984-1992, fue de 1.20% (1.09-1.94%. Existen variaciones geográficas entre las localidades de varias entidades federales. Los estados con mayor prevalencia se ubican en las regiones del occidente y centro del país, a saber: Portuguesa, Barinas, Lara, Trujillo, Cojedes y Carabobo. Por las dificultades en obtener tasas de incidencia para el Mal de Chagas, resulta adecuado emplear tasas de prevalencia para uso en salud pública, en función de su mayor estabilidad; y en el caso de Venezuela, dada la severidad menor y una sobrevivencia mayor por esta patologia hoy día. La especificidad, como parámetro de las pruebas serológicas, debería considerarse en función de la baja seroprevalencia detectada a nivel nacional. Convendría emplear varias pruebas diagnósticas en paralelo para buscar un equilibrio entre sensibilidad y especificidad.Primary investigations carried out in blood banks in Venezuela during the 1950s, indicated that overall seroprevalence for Trypanosoma cruzi infection was 12% amongst blood donors. In Venezuela, blood donation is free. All public and private blood banks are controlled by the Ministry of Health. As from 1988 the ELISA technique was uniformly used in blood banks for the detection of T. cruzi infections. Annual median

  18. Experimental Evidence of Biological Interactions among Different Isolates of Trypanosoma cruzi from the Chaco Region

    Science.gov (United States)

    Ragone, Paula G.; Pérez Brandán, Cecilia; Monje Rumi, Mercedes; Tomasini, Nicolás; Lauthier, Juan J.; Cimino, Rubén O.; Uncos, Alejandro; Ramos, Federico; Alberti D´Amato, Anahí M.; Basombrío, Miguel A.; Diosque, Patricio

    2015-01-01

    Many infectious diseases arise from co-infections or re-infections with more than one genotype of the same pathogen. These mixed infections could alter host fitness, the severity of symptoms, success in pathogen transmission and the epidemiology of the disease. Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits a high biological variability often correlated with its genetic diversity. Here, we developed an experimental approach in order to evaluate biological interaction between three T. cruzi isolates belonging to different Discrete Typing Units (DTUs TcIII, TcV and TcVI). These isolates were obtained from a restricted geographical area in the Chaco Region. Different mixed infections involving combinations of two isolates (TcIII + TcV, TcIII + TcVI and TcV + TcVI) were studied in a mouse model. The parameters evaluated were number of parasites circulating in peripheral blood, histopathology and genetic characterization of each DTU in different tissues by DNA hybridization probes. We found a predominance of TcVI isolate in blood and tissues respect to TcIII and TcV; and a decrease of the inflammatory response in heart when the damage of mice infected with TcVI and TcIII + TcVI mixture were compared. In addition, simultaneous presence of two isolates in the same tissue was not detected. Our results show that biological interactions between isolates with different biological behaviors lead to changes in their biological properties. The occurrence of interactions among different genotypes of T. cruzi observed in our mouse model suggests that these phenomena could also occur in natural cycles in the Chaco Region. PMID:25789617

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

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    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.

  20. Proliferation and differentiation of Trypanosoma cruzi inside its vector have a new trigger: redox status.

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    Natália P Nogueira

    Full Text Available Trypanosoma cruzi proliferate and differentiate inside different compartments of triatomines gut that is the first environment encountered by T. cruzi. Due to its complex life cycle, the parasite is constantly exposed to reactive oxygen species (ROS. We tested the influence of the pro-oxidant molecules H2O2 and the superoxide generator, Paraquat, as well as, metabolism products of the vector, with distinct redox status, in the proliferation and metacyclogenesis. These molecules are heme, hemozoin and urate. We also tested the antioxidants NAC and GSH. Heme induced the proliferation of epimastigotes and impaired the metacyclogenesis. β-hematin, did not affect epimastigote proliferation but decreased parasite differentiation. Conversely, we show that urate, GSH and NAC dramatically impaired epimastigote proliferation and during metacyclogenesis, NAC and urate induced a significant increment of trypomastigotes and decreased the percentage of epimastigotes. We also quantified the parasite loads in the anterior and posterior midguts and in the rectum of the vector by qPCR. The treatment with the antioxidants increased the parasite loads in all midgut sections analyzed. In vivo, the group of vectors fed with reduced molecules showed an increment of trypomastigotes and decreased epimastigotes when analyzed by differential counting. Heme stimulated proliferation by increasing the cell number in the S and G2/M phases, whereas NAC arrested epimastigotes in G1 phase. NAC greatly increased the percentage of trypomastigotes. Taken together, these data show a shift in the triatomine gut microenvironment caused by the redox status may also influence T. cruzi biology inside the vector. In this scenario, oxidants act to turn on epimastigote proliferation while antioxidants seem to switch the cycle towards metacyclogenesis. This is a new insight that defines a key role for redox metabolism in governing the parasitic life cycle.

  1. Experimental evidence of biological interactions among different isolates of Trypanosoma cruzi from the Chaco Region.

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    Paula G Ragone

    Full Text Available Many infectious diseases arise from co-infections or re-infections with more than one genotype of the same pathogen. These mixed infections could alter host fitness, the severity of symptoms, success in pathogen transmission and the epidemiology of the disease. Trypanosoma cruzi, the etiological agent of Chagas disease, exhibits a high biological variability often correlated with its genetic diversity. Here, we developed an experimental approach in order to evaluate biological interaction between three T. cruzi isolates belonging to different Discrete Typing Units (DTUs TcIII, TcV and TcVI. These isolates were obtained from a restricted geographical area in the Chaco Region. Different mixed infections involving combinations of two isolates (TcIII + TcV, TcIII + TcVI and TcV + TcVI were studied in a mouse model. The parameters evaluated were number of parasites circulating in peripheral blood, histopathology and genetic characterization of each DTU in different tissues by DNA hybridization probes. We found a predominance of TcVI isolate in blood and tissues respect to TcIII and TcV; and a decrease of the inflammatory response in heart when the damage of mice infected with TcVI and TcIII + TcVI mixture were compared. In addition, simultaneous presence of two isolates in the same tissue was not detected. Our results show that biological interactions between isolates with different biological behaviors lead to changes in their biological properties. The occurrence of interactions among different genotypes of T. cruzi observed in our mouse model suggests that these phenomena could also occur in natural cycles in the Chaco Region.

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

    Science.gov (United States)

    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

  3. 'Click chemistry' synthesis of a library of 1,2,3-triazole-substituted galactose derivatives and their evaluation against Trypanosoma cruzi and its cell surface trans-sialidase.

    Science.gov (United States)

    Carvalho, Ivone; Andrade, Peterson; Campo, Vanessa L; Guedes, Paulo M M; Sesti-Costa, Renata; Silva, João S; Schenkman, Sergio; Dedola, Simone; Hill, Lionel; Rejzek, Martin; Nepogodiev, Sergey A; Field, Robert A

    2010-04-01

    Trypanosoma cruzi trans-sialidase (TcTS) plays a key role in the recognition and invasion of host cells and in enabling the parasite to escape the human immune response. To explore this potential drug target, we have synthesized a small library of substrate analogues based on 1,4-disubstituted 1,2,3-triazole derivatives of galactose modified at either the C-1 or C-6 positions. This was achieved by coupling the appropriate azido-sugars with a panel of 23 structurally diverse terminal alkynes by using the copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction, giving a library of 46 derivatives in good to excellent yield and with complete regioselectivity. The sugar triazoles showed weak inhibition towards TcTS-catalyzed hydrolysis of 2'-(4-methylumbelliferyl)-alpha-d-N-acetylneuraminic acid in vitro (<40% inhibition at 1mM concentration); many of the compounds assessed proved to be acceptor substrates for the enzyme. Despite this modest inhibitory activity, in vitro trypanocidal activity assays against the trypomastigote form of T. cruzi Y strain revealed several compounds active in the low 100s of muM range. Further assessment of these compounds against cultured mouse spleen cells suggests a specific mode of anti-parasite action rather than a generic cytotoxic effect. PMID:20335038

  4. Metabolic labeling with (14C)-glucose of bloodstream and cell culture trypanosoma cruzi trypomastigotes:

    International Nuclear Information System (INIS)

    Trypomastigote forms of Trypanosoma cruzi from infected mouse blood and from cell culture were metabolically labeled by incubation with D-(14C)-glucose. Analysis by polyacrylamide gel electrophoresis of lysates from parasites of two strains (RA and CA1) showed a significantly different pattern. The difference was mainly quantitative when the blood and cell culture trypomastigotes of the RA strain were compared. Analysis of the culture medium by paper electrophoresis showed an anionic exometabolite only in the blood forms of both strains. (Author)

  5. Lipids shed into the culture medium by trypomastigotes of Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Agusti Rosalia

    2000-01-01

    Full Text Available Trypomastigote forms of Trypanosoma cruzi were metabolically labeled with [14C]-ethanolamine and [3H]-palmitic acid. Lipids shed to the culture medium were analyzed and compared with the parasite components. Phosphatidylcholine and lysophosphatidylcholine accounted for 53% of the total incorporated precursor. Interestingly, phosphatidylethanolamine and its lyso derivative lysophosphatidylethanolamine, although present in significant amounts in the parasites, could not be detected in the shed material. Shed lipids were highly enriched in the desaturated fatty acids C16:1 and C18:1 when compared to the total fatty acid pool isolated from the parasites.

  6. Sialoglycoconjugates in Trypanosoma cruzi-host cell interaction: possible biological model - a review

    Directory of Open Access Journals (Sweden)

    Alane Beatriz Vermelho

    1994-03-01

    Full Text Available A number of glycoconjugates, including glycolipids and glycoproteins, participate in the process of host-cell invasion by Trypanosoma cruzi and one of the most important carbohydrates involved on this interaction is sialic acid. It is known that parasite trans-sialidase participates with sialic acid in a coordinated fashion in the initial stages of invasion. Given the importance of these sialogycoconjugates, this review sets out various possible biological models for the interaction between the parasite and mammalian cells that possess a sialylated receptor/ligand system.

  7. Studies on the virulence and attenuation of Trypanosoma cruzi using immunodeficient animals

    Directory of Open Access Journals (Sweden)

    Basombrío Miguel Ángel

    2000-01-01

    Full Text Available Tissue invasion and pathology by Trypanosoma cruzi result from an interaction between parasite virulence and host immunity. Successive in vivo generations of the parasite select populations with increasing ability to invade the host. Conversely, prolonged in vitro selection of the parasite produces attenuated sublines with low infectivity for mammals. One such subline (TCC clone has been extensively used in our laboratory as experimental vaccine and tested in comparative experiments with its virulent ancestor (TUL. The experiments here reviewed aimed at the use of immunodeficient mice for testing the infectivity of TCC parasites. It has not been possible to obtain virulent, revertant sublines by prolonged passaged in such mice.

  8. Response pattern's of immunoglobulins evaluation in different lineages of mice infected with T. cruzi

    International Nuclear Information System (INIS)

    The present work has employed different mice lineages (A/J, C57BL/6, B6AF1, BXA1 and BXA2) that were challenged with different doses of T. cruzi. The objective was to evaluate the pattern of immunoglobulins response presented by resistant and susceptible mice to T. cruzi as well as the lineages developed from the matting between them. So that evaluation was done by using lineages serums' sample, analyzed by ELISA's method. In agreement with the results observed all the lineages presented higher response to IgG2a and IgG2b, if compared with the titles to IgG1. IgG1 immunoglobulins involve a type Th2 pattern response which expressed allergic immunological responses, while IgG2 involves a pattern response Th1 that expresses cellular immunological response. The different lineages used in this research also presented different immunological response pattern by the infection with T. cruzi. Mice of the lineage C57BL/6 are resistant to the infection, while the animals of the lineage A/J are susceptible. The animals of the lineage B6AF1 are more resistant to the infection than their original parental C57BL/6. The immunological response developed by hybrid mice present traces of both susceptible and resistant parental A/J and C57BL/6, respectively. The animals of the lineage BXA1 can be considered resistant to the infection, but they don't present the same control as that presented by those of the lineages B6AF1 and C57BL/6. The animals of the lineage BXA2 can be considered susceptible to the infection, but they can control it for a long period, surviving like this, longer than the animals of the lineage A/J. In addition it was observed that the IgG2b immunoglobulins are very important to the resistance of mice to T. cruzi infection. (author)

  9. Recombinant yellow fever viruses elicit CD8+ T cell responses and protective immunity against Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Raquel Tayar Nogueira

    Full Text Available Chagas' disease is a major public health problem affecting nearly 10 million in Latin America. Despite several experimental vaccines have shown to be immunogenic and protective in mouse models, there is not a current vaccine being licensed for humans or in clinical trial against T. cruzi infection. Towards this goal, we used the backbone of Yellow Fever (YF 17D virus, one of the most effective and well-established human vaccines, to express an immunogenic fragment derived from T. cruzi Amastigote Surface Protein 2 (ASP-2. The cDNA sequence of an ASP-2 fragment was inserted between E and NS1 genes of YF 17D virus through the construction of a recombinant heterologous cassette. The replication ability and genetic stability of recombinant YF virus (YF17D/ENS1/Tc was confirmed for at least six passages in Vero cells. Immunogenicity studies showed that YF17D/ENS1/Tc virus elicited neutralizing antibodies and gamma interferon (IFN-γ producing-cells against the YF virus. Also, it was able to prime a CD8(+ T cell directed against the transgenic T. cruzi epitope (TEWETGQI which expanded significantly as measured by T cell-specific production of IFN-γ before and after T. cruzi challenge. However, most important for the purposes of vaccine development was the fact that a more efficient protective response could be seen in mice challenged after vaccination with the YF viral formulation consisting of YF17D/ENS1/Tc and a YF17D recombinant virus expressing the TEWETGQI epitope at the NS2B-3 junction. The superior protective immunity observed might be due to an earlier priming of epitope-specific IFN-γ-producing T CD8(+ cells induced by vaccination with this viral formulation. Our results suggest that the use of viral formulations consisting of a mixture of recombinant YF 17D viruses may be a promising strategy to elicit protective immune responses against pathogens, in general.

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

    OpenAIRE

    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...

  11. Immune Protection against Trypanosoma cruzi Induced by TcVac4 in a Canine Model

    OpenAIRE

    José E Aparicio-Burgos; José A Zepeda-Escobar; Roberto Montes de Oca-Jimenez; Estrada-Franco, José G.; Alberto Barbabosa-Pliego; Laucel Ochoa-García; Ricardo Alejandre-Aguilar; Nancy Rivas; Giovanna Peñuelas-Rivas; Margarita Val-Arreola; Shivali Gupta; Felix Salazar-García; Garg, Nisha J.; Vázquez-Chagoyán, Juan C.

    2015-01-01

    Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GM-CSF-encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T...

  12. Trypanosoma cruzi TcI and TcII transmission among wild carnivores, small mammals and dogs in a conservation unit and surrounding areas, Brazil.

    Science.gov (United States)

    Rocha, Fabiana Lopes; Roque, André Luiz Rodrigues; Arrais, Ricardo Corassa; Santos, Jean Pierre; Lima, Valdirene dos Santos; Xavier, Samanta Cristina das Chagas; Cordeir-Estrela, Pedro; D'Andrea, Paulo Sérgio; Jansen, Ana Maria

    2013-02-01

    Aiming to better understand the ecological aspects of Trypanosoma cruzi transmission cycles, wild carnivores, small mammals and dogs were examined for T. cruzi infection in the Serra da Canastra National Park region, Brazil. Isolates were genotyped using mini-exon gene and PCR-RFLP (1f8 and H3) genomic targets. Trypanosoma cruzi transmission was well established in the area and occurred in both wild and peridomestic environments. Dog seroprevalence was 29·4% (63/214) and TcI and TcII genotypes, besides mixed infections were observed. Only TcI was detected in wild mammals. Marsupials displayed lower relative abundance, but a high prevalence of positive haemocultures (4/22), whereas rodents displayed positive haemocultures (9/113) mainly in the abundant Akodon montensis and Cerradomys subflavus species. The felid Leopardus pardalis was the only carnivore to display positive haemoculture and was captured in the same region where the small mammal prevalence of T. cruzi infection was high. Two canid species, Chrysocyon brachyurus and Cerdocyon thous, were serologically positive for T. cruzi infection (4/8 and 8/39, respectively), probably related to their capacity to exploit different ecological niches. Herein, dog infection not only signals T. cruzi transmission but also the genotypes present. Distinct transmission strategies of the T. cruzi genotypes are discussed. PMID:23062278

  13. First finding of Trypanosoma cruzi II in vampire bats from a district free of domestic vector-borne transmission in Northeastern Argentina.

    Science.gov (United States)

    Argibay, Hernán D; Orozco, M Marcela; Cardinal, M Victoria; Rinas, Miguel A; Arnaiz, María; Mena Segura, Carlos; Gürtler, Ricardo E

    2016-09-01

    Establishing the putative links between sylvatic and domestic transmission cycles of Trypanosoma cruzi, the etiological agent of Chagas disease, is of public health relevance. We conducted three surveys to assess T. cruzi infection in wild mammals from a rural and a preserved area in Misiones Province, Northeastern Argentina, which had recently been declared free of vector- and blood-borne transmission of human T. cruzi infection. A total of 200 wild mammals were examined by xenodiagnosis (XD) and/or polymerase chain reaction (PCR) amplification of the hyper-variable region of kinetoplast DNA minicircles of T. cruzi (kDNA-PCR). The overall prevalence of T. cruzi infection was 8%. Nine (16%) of 57 Didelphis albiventris opossums and two (7%) of 29 Desmodus rotundus vampire bats were positive by both XD and kDNA-PCR. Additionally, one D. rotundus positive for T. cruzi by kDNA-PCR tested positive by satellite-DNA-PCR (SAT-DNA-PCR). The T. cruzi-infected bats were captured indoors and in the yard of a vacant dwelling. All D. albiventris were infected with TcI and both XD-positive D. rotundus by TcII. Fifty-five opossum cubs within the marsupium were negative by XD. The mean infectiousness to the vector was 62% in D. albiventris and 50% in D. rotundus. Mice experimentally infected with a parasite isolate from a vampire bat displayed lesions typically caused by T. cruzi. Our study documents the presence of the genotype TcII in a sylvatic host for the first time in Argentina, and the occurrence of two transmission cycles of T. cruzi in a district free of domestic vector-borne transmission. PMID:27220254

  14. Infecção tripla por Trypanosoma cruzi, Plasmodium vivax e P. falciparum: relato de caso Triple infection by Trypanosoma cruzi, Plasmodium vivax and P. falciparum: case report

    Directory of Open Access Journals (Sweden)

    Andrea Silvestre Lobão Costa

    2012-12-01

    Full Text Available O presente registro acerca da identificação de infecção aguda de dois plasmódios e um Trypanosoma constitui evento raro. Pré-escolar, sexo feminino, 5 anos de idade, apresentou síndrome febril; foi submetida a exame de gota espessa no qual foram identificadas formas assexuadas e sexuadas de Plasmodium vivax e P. falciparum, respectivamente, além de tripomastigotas sanguíneos de Trypanosoma cruzi. No peridomicílio, foram encontrados insetos da espécie Rhodnius sp. Os autores reforçam a importância dos estudos dos ciclos peridomiciliares de T. cruzi em ambientes silvestres na Amazônia e discutem a importância da estratégia de vigilância continuada de Trypanosomas spp. nos exames de gota espessa.This report describes a rare case of acute infection caused by two Plasmodia and one Trypanosoma. 5 year-old female patient attending kindergarten presented persistent fever syndrome. She was submitted to thick smear exam, in which asexual and sexual forms of Plasmodium vivax and P. falciparum were detected, respectively, as well as trypomastigotes of Trypanosoma cruzi. Rhodnius sp. triatomines were found in the vicinity. The authors reinforce the importance of investigating the domiciliary cycles of T. cruzi in the Amazon region. Moreover, we discuss the importance of continuous monitoring of Trypanosomas spp. in thick smear exams.

  15. Differential Gel Electrophoresis (DIGE) Evaluation of Naphthoimidazoles Mode of Action: A Study in Trypanosoma cruzi Bloodstream Trypomastigotes

    Science.gov (United States)

    Brunoro, Giselle Villa Flor; Faça, Vitor Marcel; Caminha, Marcelle Almeida; Ferreira, André Teixeira da Silva; Trugilho, Monique; de Moura, Kelly Cristina Gallan; Perales, Jonas; Valente, Richard Hemmi; Menna-Barreto, Rubem Figueiredo Sadok

    2016-01-01

    Background The obligate intracellular protozoan Trypanosoma cruzi is the causative agent of Chagas disease, a neglected illness affecting millions of people in Latin America that recently entered non-endemic countries through immigration, as a consequence of globalization. The chemotherapy for this disease is based mainly on benznidazole and nifurtimox, which are very efficient nitroderivatives against the acute stage but present limited efficacy during the chronic phase. Our group has been studying the trypanocidal effects of naturally occurring quinones and their derivatives, and naphthoimidazoles derived from β-lapachone N1, N2 and N3 were the most active. To assess the molecular mechanisms of action of these compounds, we applied proteomic techniques to analyze treated bloodstream trypomastigotes, which are the clinically relevant stage of the parasite. Methodology/Principal Findings The approach consisted of quantification by 2D-DIGE followed by MALDI-TOF/TOF protein identification. A total of 61 differentially abundant protein spots were detected when comparing the control with each N1, N2 or N3 treatment, for 34 identified spots. Among the differentially abundant proteins were activated protein kinase C receptor, tubulin isoforms, asparagine synthetase, arginine kinase, elongation factor 2, enolase, guanine deaminase, heat shock proteins, hypothetical proteins, paraflagellar rod components, RAB GDP dissociation inhibitor, succinyl-CoA ligase, ATP synthase subunit B and methionine sulfoxide reductase. Conclusion/Significance Our results point to different modes of action for N1, N2 and N3, which indicate a great variety of metabolic pathways involved and allow for novel perspectives on the development of trypanocidal agents. PMID:27551855

  16. Application of core-shell PEGylated CdS/Cd(OH){sub 2} quantum dots as biolabels of Trypanosoma cruzi parasites

    Energy Technology Data Exchange (ETDEWEB)

    Chaves, C.R. [PPG Ciencias de Materiais, CCEN, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil); Fontes, A. [Departamento de Biofisica e Radiobiologia, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil)], E-mail: adriana.fontes@pesquisador.cnpq.br; Farias, P.M.A. [PPG Ciencias de Materiais, CCEN, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil); Departamento de Biofisica e Radiobiologia, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil); Santos, B.S. [Departamento de Ciencias Farmaceuticas, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil); Menezes, F.D. de; Ferreira, R.C. [Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil); Cesar, C.L. [Departamento de Eletronica Quantica, Universidade Estadual de Campinas, Cidade Universitaria, Campinas-SP 13083-970 (Brazil); Galembeck, A. [Departamento de Quimica Fundamental, Universidade Federal de Pernambuco, Cidade Universitaria, Recife-PE 50670-901 (Brazil); Figueiredo, R.C.B.Q. [Departamento de Microbiologia, Centro de Pesquisas Aggeu Magalhaes, Cidade Universitaria, Recife-PE 50670-420 (Brazil)

    2008-11-30

    Semiconductor quantum dots are a promising class of materials in the labeling of biological systems. In the present study we show the marking pattern of Trypanosoma cruzi (T. cruzi) live parasites using PEGylated CdS/Cd(OH){sub 2} fluorescent nanocrystals. The analysis obtained by confocal fluorescence microscopy and transmission electron microscopy indicates that only the endocytic paths of parasites were labeled. The parasites were alive after the incubation with the CdS/Cd(OH){sub 2}-PEG suspension. Labeling the T. cruzi with quantum dots can help to better understand the endocytosis process and also the cellular differentiation.

  17. A Two-Component DNA-Prime/Protein-Boost Vaccination Strategy for Eliciting Long-Term, Protective T Cell Immunity against Trypanosoma cruzi

    OpenAIRE

    Shivali Gupta; Garg, Nisha J.

    2015-01-01

    In this study, we evaluated the long-term efficacy of a two-component subunit vaccine against Trypanosoma cruzi infection. C57BL/6 mice were immunized with TcG2/TcG4 vaccine delivered by a DNA-prime/Protein-boost (D/P) approach and challenged with T. cruzi at 120 or 180 days post-vaccination (dpv). We examined whether vaccine-primed T cell immunity was capable of rapid expansion and intercepting the infecting T. cruzi. Our data showed that D/P vaccine elicited CD4+ (30-38%) and CD8+ (22-42%) ...

  18. CHICKEN COOPS, Triatoma dimidiata INFESTATION AND ITS INFECTION WITH Trypanosoma cruzi IN A RURAL VILLAGE OF YUCATAN, MEXICO

    Directory of Open Access Journals (Sweden)

    Edgar KOYOC-CARDEÑA

    2015-06-01

    Full Text Available This study longitudinally investigated the association between Triatoma dimidiata infestation, triatomine infection with Trypanosoma cruzi and household/backyard environmental characteristics in 101 homesteads in Molas and Yucatan, Mexico, between November 2009 (rainy season and May 2010 (dry season. Logistic regression models tested the associations between insect infestation/infection and potential household-level risk factors. A total of 200 T. dimidiata were collected from 35.6% of the homesteads, mostly (73% from the peridomicile. Of all the insects collected, 48% were infected with T. cruzi. Infected insects were collected in 31.6% of the homesteads (54.1% and 45.9% intra- and peridomiciliary, respectively. Approximately 30% of all triatomines collected were found in chicken coops. The presence of a chicken coop in the backyard of a homestead was significantly associated with both the odds of finding T. dimidiata (OR = 4.10, CI 95% = 1.61-10.43, p = 0.003 and the presence of triatomines infected with T. cruzi (OR = 3.37, CI 95% = 1.36-8.33, p = 0.006. The results of this study emphasize the relevance of chicken coops as a putative source of T. dimidiata populations and a potential risk for T. cruzi transmission.

  19. New sylvatic hosts of Trypanosoma cruzi and their reservoir competence in the humid Chaco of Argentina: a longitudinal study.

    Science.gov (United States)

    Orozco, M Marcela; Enriquez, Gustavo F; Alvarado-Otegui, Julián A; Cardinal, M Victoria; Schijman, Alejandro G; Kitron, Uriel; Gürtler, Ricardo E

    2013-05-01

    A four-year longitudinal study of the structure of sylvatic transmission cycles of Trypanosoma cruzi, reservoir host competence and parasite discrete typing units was conducted in a disturbed rural area of the humid Chaco in Argentina. Among 190 mammals examined by xenodiagnosis and polymerase chain reaction amplification, the composite prevalence of infection was substantially higher in Dasypus novemcinctus armadillos (57.7%) and Didelphis albiventris opossums (38.1%) than in Euphractus sexcinctus (20.0%), Tolypeutes matacus (12.5%), and Chaetophractus vellerosus (6.3%) armadillos. Trypanosoma cruzi was detected for the first time in Thylamys pusilla small opossums and in two unidentified small rodents. Infection was spatially aggregated only in armadillos. All Didelphis were infected with T. cruzi I and all armadillo species were infected with T. cruzi III, implying two distinct sylvatic cycles with no inputs from the domestic cycle. Dasypus armadillos and Didelphis opossums were much more infectious to vectors than other armadillos, small opossums, or rodents. PMID:23530075

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

  2. Role of CCL3/MIP-1alpha and CCL5/RANTES during acute Trypanosoma cruzi infection in rats.

    Science.gov (United States)

    Roffê, Ester; Oliveira, Fabiano; Souza, Adriano L S; Pinho, Vanessa; Souza, Danielle G; Souza, Patrícia R S; Russo, Remo C; Santiago, Helton C; Romanha, Alvaro J; Tanowitz, Herbert B; Valenzuela, Jesus G; Teixeira, Mauro M

    2010-08-01

    Chagas' disease is caused by Trypanosoma cruzi infection and is characterized by chronic fibrogenic inflammation and heart dysfunction. Chemokines are produced during infection and drive tissue inflammation. In rats, acute infection is characterized by intense myocarditis and regression of inflammation after control of parasitism. We investigated the role of CCL3 and CCL5 during infection by using DNA vaccination encoding for each chemokine separately or simultaneously. MetRANTES treatment was used to evaluate the role of CCR1 and CCR5, the receptors for CCL3 and CCL5. Vaccination with CCL3 or CCL5 increased heart parasitism and decreased local IFN-gamma production, but did not influence intensity of inflammation. Simultaneous treatment with both plasmids or treatment with MetRANTES enhanced cardiac inflammation, fibrosis and parasitism. In conclusion, chemokines CCL3 and CCL5 are relevant, but not essential, for control of T. cruzi infection in rats. On the other hand, combined blockade of these chemokines or their receptors enhanced tissue inflammation and fibrosis, clearly contrasting with available data in murine models of T. cruzi infection. These data reinforce the important role of chemokines during T. cruzi infection but suggest that caution must be taken when expanding the therapeutic modulation of the chemokine system in mice to the human infection.

  3. Sesquiterpene lactones and the diterpene 5-epi-icetexone affect the intracellular and extracellular stages of Trypanosoma cruzi

    NARCIS (Netherlands)

    Lozano, E.; Barrera, P.; Salinas, R.; Vega, I.; Nieto, M.; Tonn, C.; Kemmerling, U.; Mortara, R.A.; Sosa, M.A.

    2012-01-01

    Chagas disease is a major health problem in Latin America and is caused by the parasitic protozoan Trypanosoma cruzi. Although many drugs have been used to alleviate the disease, these have been ineffective in the chronic phase and have also presented numerous side effects on patients. In this study

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

    Science.gov (United States)

    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

  5. Comparison of seven diagnostic tests to detect Trypanosoma cruzi infection in patients in chronic phase of Chagas disease

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    Luisa Fernanda Duarte

    2014-07-01

    Full Text Available Objective: To compare the diagnostic performance of seven methods to determine Trypanosoma cruzi infection in patients with chronic Chagas disease.Methods: Analytical study, using the case-control design, which included 205 people (patients with Chagasic cardiomyopathy, n= 100; control group, n= 105. Three enzyme linked immunosorbent assays, one indirect hemagglutination assay and one immunochromatographic test were assessed. Additionally, DNA amplification was performed via the PCR method using kinetoplast and nuclear DNA as target sequences. For the comparative analysis of diagnostic tests, the parameters used were sensitivity, specificity, positive and negative predictive values, Receiver Operator Characteristic (ROC, positive and negative likelihood ratio, as well as κ quality analysis.Results: The commercial Bioelisa Chagas test showed the highest sensitivity (98%, specificity (100%, and positive and negative predictive values; additionally it had the highest discriminatory power. Otherwise, the amplification of T. cruzi DNA in blood samples showed low values of sensitivity (kinetoplast DNA= 51%, nuclear DNA= 22%, but high values of specificity (100%, and moderate to low discriminatory ability.Conclusion: The comparative analysis among the different methods suggests that the diagnostic strategy of T. cruzi infection in patients with chronic Chagas disease can be performed using ELISA assays based on recombinant proteins and/or synthetic peptides, which show higher diagnosis performance and can confirm and exclude the diagnosis of T. cruzi infection. The molecular methods show poor performance when used in the diagnosis of patients with chronic Chagas disease.

  6. Early molecular diagnosis of acute Chagas disease after transplantation with organs from Trypanosoma cruzi-infected donors.

    Science.gov (United States)

    Cura, C I; Lattes, R; Nagel, C; Gimenez, M J; Blanes, M; Calabuig, E; Iranzo, A; Barcan, L A; Anders, M; Schijman, A G

    2013-12-01

    Organ transplantation (TX) is a novel transmission modality of Chagas disease. The results of molecular diagnosis and characterization of Trypanosoma cruzi acute infection in naïve TX recipients transplanted with organs from infected deceased donors are reported. Peripheral blood and cerebrospinal fluid samples from the TX recipients of organs from infected donors were prospectively and sequentially studied for detection of T. cruzi by means of kinetoplastid DNA polymerase chain reaction (kDNA-PCR). In positive blood samples, a PCR algorithm for identification of T. cruzi Discrete Typing Units (DTUs) and quantitative real-time PCR (qPCR) to quantify parasitic loads were performed. Minicircle signatures of T. cruzi infecting populations were also analyzed using restriction fragment length polymorphism (RFLP)-PCR. Eight seronegative TX recipients from four infected donors were studied. In five, the infection was detected at 68.4 days post-TX (36-98 days). In one case, it was transmitted to two of three TX recipients. The comparison of the minicircle signatures revealed nearly identical RFLP-PCR profiles, confirming a common source of infection. The five cases were infected by DTU TcV. This report reveals the relevance of systematic monitoring of TX recipients using PCR strategies in order to provide an early diagnosis allowing timely anti-trypanosomal treatment.

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

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    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.

  8. Chagas' Disease and HIV Co-infection: Genotypic Characterization of the Trypanosoma cruzi Strain

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    Pacheco Raquel S

    1998-01-01

    Full Text Available In the past few years, new aspects of the immunopathology of Chagas' disease have been described in immunosuppressed patients, such as fatal central nervous system lesions related to the reactivation of the parasite. This article is the first description of the genotypic characterization, at the strain level, of Trypanosoma cruzi isolated from a patient with Chagas` disease/AIDS co-infection. The presence of four hypodense lesions was observed in the cranial compute tomographic scan. The diagnosis of AIDS was assessed by the detection of anti-HIV antibodies using enzyme-linked immunosorbent assay (ELISA and Western blot techniques. The CD4+ lymphocyte counts were maintained under 200 cells/mm3 during one year demonstrating the severity of the state of immunosuppression. Chagas' disease was confirmed by serological and parasitological methods. Trypomastigote forms were visualized in a thick blood smear. The parasite isolated is genotypically similar to the CL strain. The paper reinforces that cerebral Chagas' disease can be considered as another potential opportunistic infection in AIDS resulting from the reactivation of a dormant T. cruzi infection acquired years earlier.

  9. Interaction between Didelphis albiventris and Triatoma infestans in relation to Trypanosoma cruzi transmission

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    Nicolás J. Schweigmann

    1995-12-01

    Full Text Available This paper attempts to prove if a high Trypanosoma cruzi prevalence of opossums might be reached with few potential infective contacts. One non-infected Didelphis albiventris to T. cruzi and 10 infected nymphs of Triatoma infestans were left together during 23 hr in a device that simulated a natural opossum burrow. Twenty-six replicates were perfomed using marsupials and triatomines only once. Potentially infective contacts occurred in all the trials. From the 26 opossums used in trials, 54% did not eat any bug. Of the 260 bugs used, 21% were predated. In the 25 trials involving 205 surving bugs, 36 % of them did not feed. In 15/25 cases, maior ou igual a 60% of the triatomines were able to feed. The parasitological follow-up of 24 opossums showed that among 10 that had eaten bugs, 4 turned out infected and among the 14 that had not predate, 3 (21% became positive. In sum, 7/24 (29% of the marsupials acquired the infection after the experiment. This infection rate was similar to the prevalences found for the opossum population of Santiago del Estero, Argentina, suggesting that the prevalences observed in the field might be reached if each marsupial would encounter infected bugs just once in its lifetime.

  10. Identification of Protein Complex Associated with LYT1 of Trypanosoma cruzi

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    C. Lugo-Caballero

    2013-01-01

    Full Text Available To carry out the intracellular phase of its life cycle, Trypanosoma cruzi must infect a host cell. Although a few molecules have been reported to participate in this process, one known protein is LYT1, which promotes lysis under acidic conditions and is involved in parasite infection and development. Alternative transcripts from a single LYT1 gene generate two proteins with differential functions and compartmentalization. Single-gene products targeted to more than one location can interact with disparate proteins that might affect their function and targeting properties. The aim of this work was to study the LYT1 interaction map using coimmunoprecipitation assays with transgenic parasites expressing LYT1 products fused to GFP. We detected several proteins of sizes from 8 to 150 kDa that bind to LYT1 with different binding strengths. By MS-MS analysis, we identified proteins involved in parasite infectivity (trans-sialidase, development (kDSPs and histones H2A and H2B, and motility and protein traffic (dynein and α- and β-tubulin, as well as protein-protein interactions (TPR-protein and kDSPs and several hypothetical proteins. Our approach led us to identify the LYT1 interaction profile, thereby providing insights into the molecular mechanisms that contribute to parasite stage development and pathogenesis of T. cruzi infection.

  11. An ecological overview on the factors that drives to Trypanosoma cruzi oral transmission.

    Science.gov (United States)

    de Noya, Belkisyolé Alarcón; González, Oscar Noya

    2015-11-01

    American trypanosomiasis is one of the few native parasites of this continent. As a zoonosis, Trypanosoma cruzi infects about 180 species out of 25 families of mammals. Its regular transmission is through triatomines, which can easily transmit parasites either by the skin route (contamination of mammals skin with their feces) or by oral route (ingestion of food contaminated with complete triatomines or their feces) and additionally through haematogenous via (congenital and transfusional) and by tissues (transplants). The oral route, which seems to be the ancestral form of transmission to wild and domestic mammals, has recently become more important after the success achieved in the control of domicile vectors using residual pesticides. From its initial diagnosis in 1967, tens of oral outbreaks have been diagnosed mostly in the Brazilian Amazon and subsequently in other four countries in South America. Environmental imbalance caused by man through the invasion and deforestation of woodlands, results in reduction of biodiversity of mammals as food source for triatomines, affecting the "dilution effect" of T. cruzi in the nature increasing the risk of human infection. On the other hand, triatomines invade houses looking for new blood sources. One of the consequences of domiciliated triatomines is the food contamination spread, especially in home-made juices, which has been the source of infection of most oral outbreaks. Other biotic and abiotic factors help to explain the recent increase of oral transmission outbreaks of Chagas disease, distributed in nine eco-regions of America. PMID:26066984

  12. Trypanosoma cruzi Proline Transport Presents a Cell Density-dependent Regulation.

    Science.gov (United States)

    Sayé, Melisa; Miranda, Mariana R; Reigada, Chantal; Pereira, Claudio A

    2016-07-01

    Trypanosoma cruzi, the etiological agent of Chagas disease, uses proline as its main carbon source, essential for parasite growth and stage differentiation in epimastigotes and amastigotes. Since proline is mainly obtained from extracellular medium by transport proteins, in this work we studied the regulation of the T. cruzi proline transporter TcAAAP069. Proline uptake and intracellular concentration presented oscillations during epimastigote growth phases, increasing during the early exponential phase (322 pmol/min) and decreasing to undetectable levels during the late exponential phase. Transporter expression rate correlated with proline uptake, and its subcellular localization alternated from both, the plasma membrane and close to the flagellar pocket, when the transport is higher, to only the flagellar pocket region, when the transport decreased until proline uptake and TcAAAP069 protein became undetectable at the end of the growth curve. Interestingly, when parasites were treated with conditioned medium or were concentrated to artificially increase the culture density, the proline transport was completely abolished resembling the effects observed in late exponential phase. These data highlight for the first time the existence of a density-associated regulation of relevant physiological processes such as proline metabolism. PMID:26750517

  13. Proteomic of the nucleoside diphosphate kinase from T. cruzi: preliminary structural studies, expression and purification

    International Nuclear Information System (INIS)

    Full text: The enzyme nucleoside diphosphate kinase (NDPK) is a major component of the pathway for the synthesis of nucleosides triphosphates other than ATP. The mechanism of reaction involves the formation of a phospho-histidine intermediate. All known NDPK are oligomers made of small polypeptides of about 150 residues (17kDa) with a high degree of sequence similarity. T. cruzi NDPK (TcNDPK) has been characterized and could be involved in flagellar movement and therefore in the pathology of the parasite. T. cruzi NDPK (TcNDPK) has been cloned in E. coli DH5α strain. The gene has been cloned into a pRSET A plasmid and expressed in E. coli BL21-DE3 strain as a fusion protein containing TcNDPK preceded by an hexa-His-tag. The fusion protein has been purified with a HiTrap chelating column loaded with 0,1M NiSO4 in different buffer conditions and its purification level visualized in SDS-PAGE. The conformational state of the purified TcNDPK has been observed by different methods such as native PAGE. We have obtained large quantities of TcNDPK to be used for crystallization and interaction assays. The objective of this work is the resolution of the three-dimensional structure of TcNDPK by X-ray crystallography as a first step for rational drug design based on the structure. (author)

  14. The Acute Phase of Trypanosoma cruzi Infection Is Attenuated in 5-Lipoxygenase-Deficient Mice

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    Adriana M. C. Canavaci

    2014-01-01

    Full Text Available In the present work we examine the contribution of 5-lipoxygenase- (5-LO- derived lipid mediators to immune responses during the acute phase of Trypanosoma cruzi infection in 5-LO gene knockout (5-LO−/− mice and wild-type (WT mice. Compared with WT mice, the 5-LO−/− mice developed less parasitemia/tissue parasitism, less inflammatory cell infiltrates, and a lower mortality. This resistance of 5-LO−/− mice correlated with several differences in the immune response to infection, including reduced PGE2 synthesis; sustained capacity of splenocytes to produce high levels of interleukin (IL-12 early in the infection; enhanced splenocyte production of IL-1β, IL-6, and IFN-γ; rapid T-cell polarization to secrete high quantities of IFN-γ and low quantities of IL-10; and greater numbers of CD8+CD44highCD62Llow memory effector T cells at the end of the acute phase of infection. The high mortality in WT mice was associated with increased production of LTB4/LTC4, T cell bias to produce IFN-γ, high levels of serum nitrite, and marked protein extravasation into the peritoneal cavity, although survival was improved by treatment with a cys-LT receptor 1 antagonist. These data also provide evidence that 5-LO-derived mediators negatively affect host survival during the acute phase of T. cruzi infection.

  15. Internalization of components of the host cell plasma membrane during infection by Trypanosoma cruzi

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    Carvalho TMU

    1999-01-01

    Full Text Available Epimastigote and trypomastigote forms of Trypanosoma cruzi attach to the macrophage surface and are internalized with the formation of a membrane bounded vacuole, known as the parasitophorous vacuole (PV. In order to determine if components of the host cell membrane are internalized during formation of the PV we labeled the macrophage surface with fluorescent probes for proteins, lipids and sialic acid residues and then allowed the labeled cells to interact with the parasites. The interaction process was interrupted after 1 hr at 37ºC and the distribution of the probes analyzed by confocal laser scanning microscopy. During attachment of the parasites to the macrophage surface an intense labeling of the attachment regions was observed. Subsequently labeling of the membrane lining the parasitophorous vacuole containing epimastigote and trypomastigote forms was seen. Labeling was not uniform, with regions of intense and light or no labeling. The results obtained show that host cell membrane lipids, proteins and sialoglycoconjugates contribute to the formation of the membrane lining the PV containing epimastigote and trypomastigote T. cruzi forms. Lysosomes of the host cell may participate in the process of PV membrane formation.

  16. Trypanosoma cruzi: Correlations of Biological Aspects of the Life Cycle in Mice and Triatomines

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    Lima Valdirene S

    1999-01-01

    Full Text Available The infection pattern in Swiss mice and Triatomine bugs (Rhodnius neglectus of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically characterized. The clones and the original isolate were in the same zymodeme (Z1 except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice infected with the original stock and one of the clones (F8. All clones and the original isolate infected bugs well while only the original isolate and clones E2 and F3 yielded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade off i.e. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered.

  17. Expression, purification and crystallization of Trypanosoma cruzi dihydroorotate dehydrogenase complexed with orotate

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    Inaoka, Daniel Ken; Takashima, Eizo; Osanai, Arihiro; Shimizu, Hironari [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Nara, Takeshi; Aoki, Takashi [Department of Parasitology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Harada, Shigeharu [Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Kita, Kiyoshi, E-mail: kitak@m.u-tokyo.ac.jp [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2005-10-01

    The Trypanosoma cruzi dihydroorotate dehydrogenase, a key enzyme in pyrimidine de novo biosynthesis and redox homeostasis, was crystallized in complex with its first reaction product, orotate. Dihydroorotate dehydrogenase (DHOD) catalyzes the oxidation of dihydroorotate to orotate, the fourth step and the only redox reaction in the de novo biosynthesis of pyrimidine. DHOD from Trypanosoma cruzi (TcDHOD) has been expressed as a recombinant protein in Escherichia coli and purified to homogeneity. Crystals of the TcDHOD–orotate complex were grown at 277 K by the sitting-drop vapour-diffusion technique using polyethylene glycol 3350 as a precipitant. The crystals diffract to better than 1.8 Å resolution using synchrotron radiation (λ = 0.900 Å). X-ray diffraction data were collected at 100 K and processed to 1.9 Å resolution with 98.2% completeness and an overall R{sub merge} of 7.8%. The TcDHOD crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 67.87, b = 71.89, c = 123.27 Å. The presence of two molecules in the asymmetric unit (2 × 34 kDa) gives a crystal volume per protein weight (V{sub M}) of 2.2 Å{sup 3} Da{sup −1} and a solvent content of 44%.

  18. Genetic and Functional Role of TNF-alpha in the Development Trypanosoma cruzi Infection

    Science.gov (United States)

    Pissetti, Cristina Wide; Correia, Dalmo; de Oliveira, Rafael Faria; Llaguno, Maurício Manoel; Balarin, Marly Aparecida Spadotto; Silva-Grecco, Roseane Lopes; Rodrigues, Virmondes

    2011-01-01

    TNF-alpha plays an important role in trypanocidal mechanisms and is related to tissue injury. This cytokine has been detected in the heart of human chagasic patients where it is associated with tissue damage. This study investigated whether TNF-alpha levels and the presence of genetic polymorphisms are associated with the presence of T. cruzi infection and/or with the development of the cardiac form in chronic chagasic patients. Genomic DNA of 300 subjects from an endemic area was extracted and analyzed by PCR using specific primers. TNF-alpha was assayed in culture supernatants by ELISA. An association was observed between the absence of the TNF-238A allele and negative serology. Furthermore, seropositive individuals carrying the TNF-238A allele produced significantly higher TNF-alpha levels without stimulation (p = 0.04) and after stimulation with LPS (p = 0.007) and T. cruzi antigens (p = 0.004). The present results suggest that the polymorphism at position -238 influences susceptibility to infection and that this allele is associated with higher TNF-alpha production in seropositive individuals. PMID:21408088

  19. Genetic and functional role of TNF-alpha in the development Trypanosoma cruzi infection.

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    Cristina Wide Pissetti

    Full Text Available TNF-alpha plays an important role in trypanocidal mechanisms and is related to tissue injury. This cytokine has been detected in the heart of human chagasic patients where it is associated with tissue damage. This study investigated whether TNF-alpha levels and the presence of genetic polymorphisms are associated with the presence of T. cruzi infection and/or with the development of the cardiac form in chronic chagasic patients. Genomic DNA of 300 subjects from an endemic area was extracted and analyzed by PCR using specific primers. TNF-alpha was assayed in culture supernatants by ELISA. An association was observed between the absence of the TNF-238A allele and negative serology. Furthermore, seropositive individuals carrying the TNF-238A allele produced significantly higher TNF-alpha levels without stimulation (p=0.04 and after stimulation with LPS (p=0.007 and T. cruzi antigens (p=0.004. The present results suggest that the polymorphism at position -238 influences susceptibility to infection and that this allele is associated with higher TNF-alpha production in seropositive individuals.

  20. Histopathological study of experimental and natural infections by Trypanosoma cruzi in Didelphis marsupialis

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    João Carlos Araujo Carreira

    1996-10-01

    Full Text Available Didelphis marsupialis, the most important sylvatic reservoir of Trypanosoma cruzi, can also maintain in their anal scent glands the multiplicative forms only described in the intestinal tract of triatomine bugs. A study of 21 experimentally and 10 naturally infected opossums with T. cruzi was undertaken in order to establish the histopathological pattern under different conditions. Our results showed that the inflammation was predominantly lymphomacrophagic and more severe in the naturally infected animals but never as intense as those described in Chagas' disease or in other animal models. The parasitism in both groups was always mild with very scarce amastigote nests in the tissues. In the experimentally infected animals, the inflammation was directly related to the presence of amastigotes nests. Four 24 days-old animals, still in embryonic stage, showed multiple amastigotes nests and moderate inflammatory reactions, but even so they survived longer and presented less severe lesions than experimentally infected adult mice. Parasites were found in smooth, cardiac and/or predominantly striated muscles, as well as in nerve cells. Differing from the experimentally infected opossums parasitism in the naturally infected animals predominated in the heart, esophagus and stomach. Parasitism of the scent glands did not affect the histopathological pattern observed in extraglandular tissues.

  1. Trypanosoma cruzi: correlations of biological aspects of the life cycle in mice and triatomines.

    Science.gov (United States)

    Lima, V S; Mangia, R H; Carreira, J C; Marchevsky, R S; Marchewski, R S; Jansen, A M

    1999-01-01

    The infection pattern in Swiss mice and Triatomine bugs (Rhodnius neglectus) of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically characterized. The clones and the original isolate were in the same zymodeme (Z1) except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice infected with the original stock and one of the clones (F8). All clones and the original isolate infected bugs well while only the original isolate and clones E2 and F3 yielded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade off i.e. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered. PMID:10348990

  2. Trypanosoma cruzi in the scent glands of Didelphis marsupialis: the kinetics of colonization.

    Science.gov (United States)

    Carreira, J C; Jansen, A M; de Nazareth Meirelles, M; Costa e Silva, F; Lenzi, H L

    2001-03-01

    This study examined the dynamics of colonization of Trypanosoma cruzi in the scent glands of the opossum Didelphis marsupialis following direct inoculation with 10(5) epimastigotes of isolate G-49 (an opossum-derived strain). One, three, and five days, 1 month, and 1 year after inoculation, scent glands were fixed for analysis using brightfield and electron microscopies. One day after inoculation the parasites, mainly as epimastigotes, were randomly distributed into the lumen. From the third day on, the parasites still in the form of epimastigotes tended to concentrate closer to the epithelium. The flagellates reached the definitive distribution pattern on the fifth day, when they formed huge clusters deep into the foveae. In samples collected 1 month and 1 year after inoculation, the ratio of epimastigotes:trypomastigotes was 1:1, with epimastigotes predominating near the epithelium and trypomastigotes far from it. Our observations suggest that T. cruzi grows continuously in the scent glands and does not depend on adhesion to promote metacyclogenesis. Metacyclogenesis far from the epithelium seems to be an important selective advantage to both host and parasite, since it assures the elimination of the infective forms of the parasite when the host expels the glands' contents, which occurs in frightening situations or at times of stress. The morphological characteristics of infected and noninfected scent glands using transmission and scanning electron microscopies were also described. PMID:11312575

  3. Influence of Triatoma dimidiata in Modulating the Virulence of Trypanosoma cruzi Mexican Strains

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    E. Guzman-Marin

    2012-01-01

    Full Text Available The epidemiology of Chagas disease is complex. There are different vectors and reservoirs and different clinical manifestations. In order to assess whether the biological behavior of three strains isolated in southeastern Mexico (H4 isolated from human, Z17 isolated from Didelphis sp., and V isolated from T. dimidiata could be modified during passage through the vector T. dimidiata, the parasitemia curve, the amount of amastigote nests, and mortality of BALB/c infected with blood trypomastigotes of T. cruzi were evaluated. Strains were maintained in continuous passage from mouse to mouse and in animals infected with metacyclic trypomastigotes. The parasitemia curves were significantly different ( between mice to mice and triatoma to mice groups in strains H4 and Z17, and was also observed fewer amastigote nests in cardiac tissue ( strain H4 with higher number versus all groups and Z17 between mice to mice and triatoma to mice 45 days after inoculation. It is concluded that T. dimidiata influences in modulating the virulence of strains of T. cruzi in the region. Further studies of the intestinal tract of the insect in search for some protein molecules involved in regulating may clarify the virulence of the parasite.

  4. Crystallization and preliminary X ray analysis of nucleoside diphosphate kinase 1 from T. cruzi

    International Nuclear Information System (INIS)

    Introduction: Trypanosoma cruzi is the etiologic agent of Chagas disease. The Nucleoside diphosphate kinases (NDPKs) are enzymes involved in energy management and nucleoside balance in the cell. T. cruzi TcNDPK1, a canonical isoform. The objective of this work is obtaining protein's crystals, diffract and process the data for tridimensional structure resolution. Materials and Methods: TcNDPK1 was expressed in E. coli as a fusion protein with Nterminal His-tag. TcNDPK1 was overexpressed and purified by FPLC. Crystallization was assayed by sitting drop and hanging drop vapor diffusion method. Crystals was frozen and diffracted on synchrotron x-ray radiation in Campinas (Brasil). The data set collected was reduced and merged using MOSFLM and SCALA programs. Results and Discussion: His-TcNDPK was overexpressed, purified and crystallized. The crystals are diffracted and collected the data to 3.5A. The crystals belong to the trigonal space group P3, with unit cell parameters a=127.94, b=127.84, c=275.49. Structure determination is under way. These results will provide relevant information that could be the first step in rational drug design for treating Chagas disease.(authors)

  5. Evaluation of VDR gene polymorphisms in Trypanosoma cruzi infection and chronic Chagasic cardiomyopathy.

    Science.gov (United States)

    Leon Rodriguez, Daniel A; Carmona, F David; González, Clara Isabel; Martin, Javier

    2016-01-01

    Vitamin D is an important modulator of the immune response. It acts over several immune cell types where the Vitamin D receptor (VDR) is expressed. Due to the high relevance of this signaling pathway, several studies have investigated the possible influence of genes involved in the metabolism of Vitamin D and its receptor in different human diseases. Here, we analyzed whether four single-nucleotide polymorphisms of the VDR gene (rs731236, rs7975232, rs1544410 and rs2228570) are involved in the susceptibility to infection by Trypanosoma cruzi and/or to chronic Chagas cardiomyopathy (CCC) in a Colombian endemic population for this parasite. Our results showed that the rs2228570*A allele is associated with CCC development (P = 4.46E-03, OR = 1.51). In summary, the data presented in this report suggest that variation within the VDR gene may affect the immune response against T. cruzi, increasing the probability of cardiac complications in infected individuals. PMID:27502545

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

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    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.

  7. Analysis of the transmission of Trypanosoma cruzi infection through hosts and vectors.

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    Fabrizio, María C; Schweigmann, Nicolás J; Bartoloni, Norberto J

    2016-08-01

    Calculating epidemiological measures of infection by Trypanosoma cruzi, the causative agent of Chagas disease, is complex, because it involves several species, different stages of infection in humans and multiple transmission routes. Using the next-generation matrix method, we analysed a model which considers the three stages of human infection, triatomines and dogs (the main domestic reservoirs of T. cruzi when triatomines are present) and the main transmission routes. We derived R 0 and type-reproduction numbers T. We deduced formulas for the number of new infections generated through each transmission route by each infected individual. We applied our findings in Argentine Gran Chaco. The expressions achieved allowed quantifying the high infectivity of dogs and emphasizing the epidemiological importance of the long and asymptomatic chronic indeterminate stage in humans in the spread of the infection. According to the model, it is expected that one infected human infects 21 triatomines, that 100 infected triatomines are necessary to infect one human and 34 to infect a dog, and that each dog infects on average one triatomine per day. Our results may allow quantifying the effect of control measures on infected humans, triatomines and dogs (or other highly infected vertebrate) or on a specific route of transmission, in other scenarios. PMID:27039662

  8. Comparison of conventional serology and PCR methods for the routine diagnosis of Trypanosoma cruzi infection

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    Soraia Reda Gilber

    2013-06-01

    Full Text Available Introduction Trypanosoma cruzi, a flagellated protozoan, is the etiologic agent of Chagas disease, and it is estimated that approximately 5 million people in Brazil are infected with this parasite. This work aimed to compare the current diagnostic methods for Chagas disease, including conventional serological (IFAT and ELISA and molecular techniques (PCR, to introduce PCR as an auxiliary technique. Methods A total of 106 chagasic patients were evaluated: 88 from endemic areas of Parana, 6 from São Paulo, 3 from Minas Gerais, 3 from Rio Grande do Sul, 1 from Bahia and 5 from the Santa Catarina T. cruzi outbreak. The samples were analyzed by conventional serological methods (IFAT, ELISA, hemoculture and PCR to confirm Chagas disease. Results When IFAT was used to determine antibody levels, the sensitivity was 81.7% for patients with the cardiac form of the disease and 100% for the other clinical forms. In contrast, ELISA showed 84% sensitivity and 100% specificity. The use of serological and molecular techniques and their implications for the diagnosis of Chagas disease in non-endemics area are discussed. Conclusions PCR constitutes an excellent support methodology for the laboratory diagnosis of Chagas disease due to its high sensitivity and specificity.

  9. Membrane cholesterol regulates lysosome-plasma membrane fusion events and modulates Trypanosoma cruzi invasion of host cells.

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    Bárbara Hissa

    Full Text Available BACKGROUND: Trypomastigotes of Trypanosoma cruzi are able to invade several types of non-phagocytic cells through a lysosomal dependent mechanism. It has been shown that, during invasion, parasites trigger host cell lysosome exocytosis, which initially occurs at the parasite-host contact site. Acid sphingomyelinase released from lysosomes then induces endocytosis and parasite internalization. Lysosomes continue to fuse with the newly formed parasitophorous vacuole until the parasite is completely enclosed by lysosomal membrane, a process indispensable for a stable infection. Previous work has shown that host membrane cholesterol is also important for the T. cruzi invasion process in both professional (macrophages and non-professional (epithelial phagocytic cells. However, the mechanism by which cholesterol-enriched microdomains participate in this process has remained unclear. METHODOLOGY/PRINCIPAL FINDING: In the present work we show that cardiomyocytes treated with MβCD, a drug able to sequester cholesterol from cell membranes, leads to a 50% reduction in invasion by T. cruzi trypomastigotes, as well as a decrease in the number of recently internalized parasites co-localizing with lysosomal markers. Cholesterol depletion from host membranes was accompanied by a decrease in the labeling of host membrane lipid rafts, as well as excessive lysosome exocytic events during the earlier stages of treatment. Precocious lysosomal exocytosis in MβCD treated cells led to a change in lysosomal distribution, with a reduction in the number of these organelles at the cell periphery, and probably compromises the intracellular pool of lysosomes necessary for T. cruzi invasion. CONCLUSION/SIGNIFICANCE: Based on these results, we propose that cholesterol depletion leads to unregulated exocytic events, reducing lysosome availability at the cell cortex and consequently compromise T. cruzi entry into host cells. The results also suggest that two different pools of

  10. Importance of species of Triatominae (Heteroptera: Reduviidae) in risk of transmission of Trypanosoma cruzi in western Mexico.

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    Martínez-Ibarra, J A; Grant-Guillén, Y; Morales-Corona, Z Y; Haro-Rodríguez, S; Ventura-Rodríguez, L V; Nogueda-Torres, B; Bustos-Saldaña, R

    2008-05-01

    The epidemiological risk of infection by Trypanosoma cruzi Chagas in human populations of western Mexico is still under study. Although most vectors in this region and their vector capability are already known, new studies estimating the risk and the importance of individual Triatominae species (Hemiptera: Reduviidae) for T. cruzi transmission are necessary. For 1 yr, every month, > 400 human dwellings and their surroundings in eight communities of two western Mexico states were searched for triatomines. More than 1,000 specimens representing four species were collected and checked for T. cruzi infection. Based on the usual entomological indices, only the inhabitants of Gavilán El Progreso-La Villita are at serious risk of vectorial infection by T. cruzi. A population of Meccus longipennis (Usinger) was found living in peridomestic rock pile boundary walls after an insecticide spraying. It was confirmed the major role of peridomestic habitats as shelter areas for triatomines, particularly in rock pile boundary walls and chicken roosts. Triatominae presence also was verified in certain sylvatic habitats, including primarily heaps of stones. The important role of M. longipennis in the potential transmission of T. cruzi in the region and the secondary role of M. picturatus (Usinger) and Triatoma barberi Usinger also were confirmed. Null colonization of houses by T. barberi, which was collected primarily in peridomestic habitats, differs from its common intradomiciliary collection in other studies. Meccus pallidipennis (Stål) most probably does not exist in Nayarit. Meccus mazzottii (Usinger) and Meccus phyllosomus (Burmeister) are no longer found in Nayarit and Jalisco. Additional studies are necessary to determine the current epidemiological situation in other areas of western Mexico.

  11. Prevalence of antibodies to Trypanosoma cruzi, Toxoplasma gondii, Encephalitozonn cuniculi, Sarcocystis neurona, Besnoitia darlingi, and Neospora caninum in North American opossum, Didelphis virginiana, from Southern Louisian

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    We examined the prevalence of antibodies to zoonotic protozoan parasites (Trypanosoma cruzi, Toxoplasma gondii, and Encephalitozoon cuniculi) and protozoan’s of veterinary importance (Neospora caninum, Sarcocystis neurona and Besnoitia darlingi) in a population of North American opossums (Didelphis...

  12. On the tissular parasitism of Trypanosoma cruzi y strain in swiss mice Sobre o parasitismo tecidual da cepa Y do Trypanosoma cruzi em camundongos albinos (Swiss-Webster

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    Maria Auxiliadora de Sousa

    1984-12-01

    Full Text Available A review of the tissular parasitism of Trypanosoma cruzi Y strain in Swiss mice was carried out. This strain parasitized preferentially smooth, skeletal and cardiac muscle fibers, with low transitory spleen and liver parasitism, as previously found by some Authors, although differing from other reports. These results can be related to the host genetical constitution and/or the degree of the strain virulence at the time of this study. Furthermore, we discuss that the high macrophagotropism reported for this strain in some instances could be an artificially induced condition resulting from its serial maintenance in mice, either for a longer time and/or by using young animals. The heavy parasitism and inflammation observed in the bladder, pancreas and spermatic duct of some inoculated mice, as well as the testis parasitization, were also noteworthy findings.Através deste trabalho fizemos uma revisão do parasitismo tecidual da cepa Y do Trypanosoma cruzi em camundongos albinos (Swiss-Webster. Esta cepa parasitou preferencialmente as fibras musculares lisas, esqueléticas e cardíacas, sendo baixo e transitório seu parasitismo do baço e fígado, conforme já observado por alguns Autores, embora diferindo de outros achados. Estes resultados podem estar relacionados com o padrão genético do hospedeiro e/ou com o grau de virulência da cepa por ocasião deste estudo. Além do mais, discutimos a possibilidade de que o intenso macrofagotropismo descrito para esta cepa em algumas ocasiões possa ser uma condição artificialmente induzida através de sua manutenção seriada em camundongos por tempo prolongado e/ou pelo uso de animais jovens. Também são dignos de nota, o intenso parasitismo e inflamação da bexiga, pâncreas e canal espermático de alguns animais inoculados, assim como, o encontro de ninhos de amastigotas no testículo.

  13. Modulation of parasitemia and antibody responce to Trypanosoma cruzy by cyclophosphamide in Calomys callosus (Rodentia, Cricetidae Modulação da parasitemia e da resposta de anticorpos ao Trypanosoma cruzi pela ciclofosfamida em Calomys callosus (Rodentia, Cricetidae

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    Monamaris Marques Borges

    1992-02-01

    Full Text Available Calomys callosus a wild rodent, previously described as harboring Trypanosoma cruzi, has a low susceptibility to infection by this protozoan. Experiments were designed to evaluate the contribution of the immune response to the resistance to T. cruzi infection exhibited by C. calossus. Animals were submitted to injections of high (200 mg/kg body weight and low (20 mg/kg body weight doses of cyclophosphamide on days -1 or -1 and +5, and inoculated with 4 x 10³ T. cruzi on day O. Parasitemia, mortality and antibody response as measured by direct agglutination of trypomastigotes were observed. Two hundred mg doses of cyclophosphamide resulted in higher parasitemia and mortality as well as in suppression of the antibody response. A single dose of 20 mg enhanced antibody levels on the 20th day after infection, while an additional dose did not further increase antibody production. Parasitemia levels were not depressed, but rather increased in both these groups as compared to untreated controls. Passive transfer of hyperimmune C. callosus anti-T. cruzi serum to cyclophosphamide immunosuppressed animals resulted in lower parasitemia and mortality rates. T