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Sample records for cruzi bloodstream trypomastigotes

  1. Metabolic labeling with (14C)-glucose of bloodstream and cell culture trypanosoma cruzi trypomastigotes:

    International Nuclear Information System (INIS)

    Lederkremer, R.M. de; Groisman, J.F.; Lima, C.; Katzin, A.

    1990-01-01

    Trypomastigote forms of Trypanosoma cruzi from infected mouse blood and from cell culture were metabolically labeled by incubation with D-( 14 C)-glucose. Analysis by polyacrylamide gel electrophoresis of lysates from parasites of two strains (RA and CA 1 ) 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) [es

  2. Differential Gel Electrophoresis (DIGE Evaluation of Naphthoimidazoles Mode of Action: A Study in Trypanosoma cruzi Bloodstream Trypomastigotes.

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    Giselle Villa Flor Brunoro

    2016-08-01

    Full Text Available 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.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.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.

  3. Anti-proliferative effect of the essential oil of Cymbopogon citratus (DC) Stapf (lemongrass) on intracellular amastigotes, bloodstream trypomastigotes and culture epimastigotes of Trypanosoma cruzi (Protozoa: Kinetoplastida).

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    Santoro, G F; Cardoso, M G; Guimarães, L G L; Freire, J M; Soares, M J

    2007-10-01

    This study analyses the anti-proliferative effect of lemongrass essential oil and its main constituent (citral) on all 3 evolutive forms of Trypanosoma cruzi. Steam distillation was used to obtain lemongrass essential oil, with chemical composition determined by gas chromatography (GC) and GC coupled to mass spectrometry (GC-MS). The IC50/24 h (concentration that reduced the parasite population by 50%) of the oil and of citral upon T. cruzi was determined by cell counting in a Neubauer chamber, while morphological alterations were visualized by scanning and transmission electron microscopy. Treatment with the essential oil resulted in epimastigote growth inhibition with IC50=126.5 microg/ml, while the IC50 for trypomastigote lysis was 15.5 microg/ml. The IC50/48 h for the Association Index (% macrophage infection x number of amastigotes per cell) was 5.1 microg/ml, with a strong inhibition of intracellular amastigote proliferation. Ultrastructural analysis demonstrated cytoplasmic and nuclear extraction, while the plasma membrane remained morphologically preserved. Our data show that lemongrass essential oil is effective against T. cruzi trypomastigotes and amastigotes, and that its main component, citral, is responsible for the trypanocidal activity. These results indicate that essential oils can be promising anti-parasitic agents, opening perspectives to the discovery of more effective drugs of vegetal origin for treatment of parasitic diseases. However, additional cytotoxicity experiments on different cell lines and tests in a T. cruzi-mouse model are needed to support these data.

  4. 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.

  5. 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

  6. Quantitative Proteomic and Phosphoproteomic Analysis of Trypanosoma cruzi Amastigogenesis

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

    2014-01-01

    Chagas disease is a tropical neglected disease endemic in Latin America and it is caused by the protozoan Trypanosoma cruzi. The parasite has four major life stages: epimastigote, metacyclic trypomastigote, bloodstream trypomastigote and amastigote. The differentiation from infective trypomastigo......Chagas disease is a tropical neglected disease endemic in Latin America and it is caused by the protozoan Trypanosoma cruzi. The parasite has four major life stages: epimastigote, metacyclic trypomastigote, bloodstream trypomastigote and amastigote. The differentiation from infective...

  7. Insight into the exoproteome of the tissue-derived trypomastigote form of trypanosoma cruzi

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    Queiroz, Rayner M L; Ricart, Carlos A O; Machado, Mara O

    2016-01-01

    The protozoan parasite Trypanosoma cruzi causes Chagas disease, one of the major neglected infectious diseases. It has the potential to infect any nucleated mammalian cell. The secreted/excreted protein repertoire released by T. cruzi trypomastigotes is crucial in host-pathogen interactions...

  8. Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C.

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    Villamizar, Luz Helena; Cardoso, Maria das Graças; Andrade, Juliana de; Teixeira, Maria Luisa; Soares, Maurilio José

    2017-02-01

    Recent studies showed that essential oils from different pepper species (Piper spp.) have promising leishmanicidal and trypanocidal activities. In search for natural compounds against Trypanosoma cruzi, different forms of the parasite were incubated for 24 h at 28ºC or 4ºC with Piper aduncum essential oil (PaEO) or its main constituents linalool and nerolidol. PaEO chemical composition was obtained by GC-MS. Drug activity assays were based on cell counting, MTT data or infection index values. The effect of PaEO on the T. cruzi cell cycle and mitochondrial membrane potential was evaluated by flow cytometry. PaEO was effective against cell-derived (IC50/24 h: 2.8 μg/mL) and metacyclic (IC50/24 h: 12.1 μg/mL) trypomastigotes, as well as intracellular amastigotes (IC50/24 h: 9 μg/mL). At 4ºC - the temperature of red blood cells (RBCs) storage in blood banks - cell-derived trypomastigotes were more sensitive to PaEO (IC50/24 h = 3.8 μg/mL) than to gentian violet (IC50/24 h = 24.7 mg/mL). Cytotoxicity assays using Vero cells (37ºC) and RBCs (4ºC) showed that PaEO has increased selectivity for cell-derived trypomastigotes. Flow cytometry analysis showed that PaEO does not affect the cell cycle of T. cruzi epimastigotes, but decreases their mitochondrial membrane potential. GC-MS data identified nerolidol and linalool as major components of PaEO, and linalool had trypanocidal effect (IC50/24 h: 306 ng/mL) at 4ºC. The trypanocidal effect of PaEO is likely due to the presence of linalool, which may represent an interesting candidate for use in the treatment of potentially contaminated RBCs bags at low temperature.

  9. Linalool, a Piper aduncum essential oil component, has selective activity against Trypanosoma cruzi trypomastigote forms at 4°C

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    Luz Helena Villamizar

    Full Text Available BACKGROUND Recent studies showed that essential oils from different pepper species (Piper spp. have promising leishmanicidal and trypanocidal activities. OBJECTIVES In search for natural compounds against Trypanosoma cruzi, different forms of the parasite were incubated for 24 h at 28ºC or 4ºC with Piper aduncum essential oil (PaEO or its main constituents linalool and nerolidol. METHODS PaEO chemical composition was obtained by GC-MS. Drug activity assays were based on cell counting, MTT data or infection index values. The effect of PaEO on the T. cruzi cell cycle and mitochondrial membrane potential was evaluated by flow cytometry. FINDINGS PaEO was effective against cell-derived (IC50/24 h: 2.8 μg/mL and metacyclic (IC50/24 h: 12.1 μg/mL trypomastigotes, as well as intracellular amastigotes (IC50/24 h: 9 μg/mL. At 4ºC - the temperature of red blood cells (RBCs storage in blood banks - cell-derived trypomastigotes were more sensitive to PaEO (IC50/24 h = 3.8 μg/mL than to gentian violet (IC50/24 h = 24.7 mg/mL. Cytotoxicity assays using Vero cells (37ºC and RBCs (4ºC showed that PaEO has increased selectivity for cell-derived trypomastigotes. Flow cytometry analysis showed that PaEO does not affect the cell cycle of T. cruzi epimastigotes, but decreases their mitochondrial membrane potential. GC-MS data identified nerolidol and linalool as major components of PaEO, and linalool had trypanocidal effect (IC50/24 h: 306 ng/mL at 4ºC. MAIN CONCLUSION The trypanocidal effect of PaEO is likely due to the presence of linalool, which may represent an interesting candidate for use in the treatment of potentially contaminated RBCs bags at low temperature.

  10. Comprehensive glycoprofiling of the epimastigote and trypomastigote stages of Trypanosoma cruzi

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    Alves, Maria Julia Manso; Kawahara, Rebeca; Viner, Rosa

    2017-01-01

    Trypanosoma cruzi, the protozoan that causes Chagas disease, has a complex life cycle involving insect and mammalian hosts and distinct developmental stages. During T. cruzi developmental stages, glycoproteins play important role in the host-parasite interaction, such as cellular recognition, host...... the significant T. cruzi stage-specific expression of glycoproteins that can help to better understand the T. cruzi phenotype and response caused by the interaction with different hosts during its complex life cycle. BIOLOGICAL SIGNIFICANCE: Chagas disease caused by the protozoan Trypanosoma cruzi is a neglected...... disease which affects millions of people especially in Latin America. The absence of efficient drugs and vaccines against Chagas disease stimulates the search for novel targets. Glycoproteins are very attractive therapeutic candidate targets since they mediate key processes in the host...

  11. Adhesion of Trypanosoma cruzi trypomastigotes to fibronectin or laminin modifies tubulin and paraflagellar rod protein phosphorylation.

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    Eliciane C Mattos

    Full Text Available BACKGROUND: The unicellular parasite Trypanosoma cruzi is the causative agent of Chagaś disease in humans. Adherence of the infective stage to elements of the extracellular matrix (ECM, as laminin and fibronectin, is an essential step in host cell invasion. Although members of the gp85/TS, as Tc85, were identified as laminin and fibronectin ligands, the signaling events triggered on the parasite upon binding to these molecules are largely unexplored. METHODOLOGY/PRINCIPAL FINDINGS: Viable infective parasites were incubated with laminin, fibronectin or bovine serum albumin for different periods of time and the proteins were separated by bidimensional gels. The phosphoproteins were envisaged by specific staining and the spots showing phosphorylation levels significantly different from the control were excised and identified by MS/MS. The results of interest were confirmed by immunoblotting or immunoprecipitation and the localization of proteins in the parasite was determined by immunofluorescence. Using a host cell-free system, our data indicate that the phosphorylation contents of T. cruzi proteins encompassing different cellular functions are modified upon incubation of the parasite with fibronectin or laminin. CONCLUSIONS/SIGNIFICANCE: Herein it is shown, for the first time, that paraflagellar rod proteins and α-tubulin, major structural elements of the parasite cytoskeleton, are predominantly dephosphorylated during the process, probably involving the ERK1/2 pathway. It is well established that T. cruzi binds to ECM elements during the cell infection process. The fact that laminin and fibronectin induce predominantly dephosphorylation of the main cytoskeletal proteins of the parasite suggests a possible correlation between cytoskeletal modifications and the ability of the parasite to internalize into host cells.

  12. Polyclonal cell activity of a repeat peptide derived from the sequence of an 85-kilodalton surface protein of Trypanosoma cruzi trypomastigotes.

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    Pestel, J; Defoort, J P; Gras-Masse, H; Afchain, D; Capron, A; Tartar, A; Ouaissi, A

    1992-01-01

    Some in vitro and in vivo biological activities of an octadecapeptide derived from an 85-kDa surface protein of Trypanosoma cruzi trypomastigote were studied. The peptide coupled to a carrier protein induced the proliferative response of lymph node cells from mice immunized with various antigens. Moreover, sera from mice immunized with the coupled peptide were found to contain antibodies against a number of self and nonself antigens: fibronectin, bovine serum albumin, myosin, tetanus toxoid, ovalbumin, keyhole limpet hemocyanin, and DNA. These results are discussed in the context of Chagas' disease immunopathology. PMID:1730508

  13. Early and late molecular and morphologic changes that occur during the in vitro transformation of Trypanosoma cruzi metacyclic trypomastigotes to amastigotes

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    VÍCTOR T CONTRERAS

    2002-01-01

    Full Text Available The amastigogenesis primary of T. cruzi occurs naturally when metacyclic trypomastigotes transform into amastigotes within the cells of the mammalian host. The in vitro study of the macromolecular changes that occur over several days during the transformation process should provide significant indications of how the parasite adapts to the mammalian host environment. We show here that metacyclic trypomastigotes pre-incubated at 37° C in a protein-rich medium reach a high degree of transformation to amastigotes when re-incubated in the fresh medium. Giemsa-stained smears show that during the pre-incubation phase, the metacyclic trypomastigotes undergo lengthening at the posterior end and a thinning out of the entire body. SDS-PAGE analysis of polypeptides and glycopeptides or Western blot with stage-specific antisera analyses indicate that the in vitro primary amastigogenesis is associated with abrupt changes in protein, glycoprotein, and stage-specific antigens that occur simultaneously during the first 24 hours of pre-incubation. Since the differentiating system consists of a rich media at 37° C, temperature and medium constitution must trigger a macromolecular differentiation to amastigotes that precedes the morphological transformation by several days. This transformation is associated with the rearrangement of stage-specific antigens and takes place when the culture medium is changed.

  14. Evaluation of some organic compounds on bloodstream forms of Trypanosoma cruzi

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    João S. Silva

    1992-09-01

    Full Text Available Accidental transmission of Chagas' disease to man by blood transfusion is a serious problem in Latin-America. This paper describes the testing of several synthetic, semi-synthetic, and natural compounds for their activity against blood trypomastigotes in vitro at 4-C. The compounds embody several types of chemical structures: benzoquinone, naphthoquinone, anthracenequinone, phenanthrenequinone, imidazole, piperazine, quinoline, xanthene, and simple benzenic and naphthalenic derivates. Some of them are for the first time tested against Trypanosoma cruzi. The toxic effect these compounds on this parasite was done by two quite distinct sets of experiments. In one set, the compounds were added to infected blood as ethanolic solution. In this situation the most active one was a furan-1, 2-naphthoquinone, in the same range as gentian violet, a new fact to be considered in the assessment of structure-activity relationships in this class of compounds. In other set, we tentatively evaluated the biological activity of water insoluble compounds by adding them in a pure form without solvent into infected blood. In this way some appear to be very active and it was postulated that the effectiveness of such compounds must result from interactions between them and specific blood components.

  15. Trypanosoma cruzi: Serum levels of nitric oxide and expression of inducible nitric oxide synthase in myocardium and spleen of dogs in the acute stage of infection with metacyclic or blood trypomastigotes.

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    Vieira, Paula Melo de Abreu; Francisco, Amanda Fortes; de Souza, Sheler Martins; Malaquias, Luiz Cosme Cotta; Reis, Alexandre Barbosa; Giunchetti, Rodolfo Cordeiro; Veloso, Vanja Maria; de Lana, Marta; Tafuri, Washington Luiz; Carneiro, Cláudia Martins

    2009-01-01

    The participation of nitric oxide (NO) in the control of blood parasitemia and parasitism during the acute phase of infection in dogs inoculated with blood trypomastigotes (BT) or metacyclic trypomastigotes (MT group) of Berenice-78 Trypanosoma cruzi strain has been evaluated. Animals of the MT group (n=4) presented increased levels of serum NO throughout the infection when compared with the BT (n=4) or control (n=4) groups, and a delay in parasitemia peak compared with the BT group. In spleen fragments, tissue parasitism was not observed but the MT group presented larger areas associated with inducible NO synthase (iNOS) in relation to BT and control groups. Heart fragments of MT-infected animals exhibited comparatively low tissue parasitism and high iNOS expression, while animals of the BT group presented high inflammatory infiltrate, high tissue parasitism and low iNOS expression. These results indicate that the source of inoculum can interfere with the development of the acute phase of Chagas disease, and may also trigger a distinct parasite-host interaction during this phase.

  16. Evasion of the Immune Response by Trypanosoma cruzi during Acute Infection

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    Cardoso, Mariana S.; Reis-Cunha, João Luís; Bartholomeu, Daniella C.

    2016-01-01

    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 glycosylphosphatidylinositol-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 coexpression 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

  17. Trypanosoma cruzi Evades the Complement System as an Efficient Strategy to Survive in the Mammalian Host: The Specific Roles of Host/Parasite Molecules and Trypanosoma cruzi Calreticulin

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    Galia Ramírez-Toloza

    2017-09-01

    Full Text Available American Trypanosomiasis is an important neglected reemerging tropical parasitism, infecting about 8 million people worldwide. Its agent, Trypanosoma cruzi, exhibits multiple mechanisms to evade the host immune response and infect host cells. An important immune evasion strategy of T. cruzi infective stages is its capacity to inhibit the complement system activation on the parasite surface, avoiding opsonizing, immune stimulating and lytic effects. Epimastigotes, the non-infective form of the parasite, present in triatomine arthropod vectors, are highly susceptible to complement-mediated lysis while trypomastigotes, the infective form, present in host bloodstream, are resistant. Thus T. cruzi susceptibility to complement varies depending on the parasite stage (amastigote, trypomastigotes or epimastigote and on the T. cruzi strain. To avoid complement-mediated lysis, T. cruzi trypomastigotes express on the parasite surface a variety of complement regulatory proteins, such as glycoprotein 58/68 (gp58/68, T. cruzi complement regulatory protein (TcCRP, trypomastigote decay-accelerating factor (T-DAF, C2 receptor inhibitor trispanning (CRIT and T. cruzi calreticulin (TcCRT. Alternatively, or concomitantly, the parasite captures components with complement regulatory activity from the host bloodstream, such as factor H (FH and plasma membrane-derived vesicles (PMVs. All these proteins inhibit different steps of the classical (CP, alternative (AP or lectin pathways (LP. Thus, TcCRP inhibits the CP C3 convertase assembling, gp58/68 inhibits the AP C3 convertase, T-DAF interferes with the CP and AP convertases assembling, TcCRT inhibits the CP and LP, CRIT confers ability to resist the CP and LP, FH is used by trypomastigotes to inhibit the AP convertases and PMVs inhibit the CP and LP C3 convertases. Many of these proteins have similar molecular inhibitory mechanisms. Our laboratory has contributed to elucidate the role of TcCRT in the host

  18. Cell signaling during Trypanosoma cruzi invasion

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    Fernando Yukio Maeda

    2012-11-01

    Full Text Available Cell signaling is an essential requirement for mammalian cell invasion by Trypanosoma cruzi. Depending on the parasite strain and the parasite developmental form, distinct signaling pathways may be induced. In this short review, we focus on the data coming from studies with metacyclic trypomastigotes (MT generated in vitro and tissue culture-derived trypomastigotes (TCT, used as counterparts of insect-borne and bloodstream parasites respectively. During invasion of host cells by MT or TCT, intracellular Ca2+ mobilization and host cell lysosomal exocytosis are triggered. Invasion mediated by MT surface molecule gp82 requires the activation of mammalian target of rapamycin (mTOR, phosphatidylinositol 3-kinase (PI3K and protein kinase C (PKC in the host cell, associated with Ca2+-dependent disruption of the actin cytoskeleton. In MT, protein tyrosine kinase (PTK, PI3K, phospholipase C (PLC and PKC appear to be activated. TCT invasion, on the other hand, does not rely on mTOR activation, rather on target cell PI3K, and may involve the host cell autophagy for parasite internalization. Enzymes, such oligopeptidase B and the major T. cruzi cysteine proteinase cruzipain, have been shown to generate molecules that induce target cell Ca2+ signal. In addition, TCT may trigger host cell responses mediated by TGF-β receptor or integrin family member. Further investigations are needed for a more complete and detailed picture of T. cruzi invasion.

  19. 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

  20. MDL28170, a calpain inhibitor, affects Trypanosoma cruzi metacyclogenesis, ultrastructure and attachment to Rhodnius prolixus midgut.

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    Vítor Ennes-Vidal

    Full Text Available BACKGROUND: Trypanosoma cruzi is the etiological agent of Chagas' disease. During the parasite life cycle, many molecules are involved in the differentiation process and infectivity. Peptidases are relevant for crucial steps of T. cruzi life cycle; as such, it is conceivable that they may participate in the metacyclogenesis and interaction with the invertebrate host. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we have investigated the effect of the calpain inhibitor MDL28170 on the attachment of T. cruzi epimastigotes to the luminal midgut surface of Rhodnius prolixus, as well as on the metacyclogenesis process and ultrastructure. MDL28170 treatment was capable of significantly reducing the number of bound epimastigotes to the luminal surface midgut of the insect. Once the cross-reactivity of the anti-Dm-calpain was assessed, it was possible to block calpain molecules by the antibody, leading to a significant reduction in the capacity of adhesion to the insect guts by T. cruzi. However, the antibodies were unable to interfere in metacyclogenesis, which was impaired by the calpain inhibitor presenting a significant reduction in the number of metacyclic trypomastigotes. The calpain inhibitor also promoted a direct effect against bloodstream trypomastigotes. Ultrastructural analysis of epimastigotes treated with the calpain inhibitor revealed disorganization in the reservosomes, Golgi and plasma membrane disruption. CONCLUSIONS/SIGNIFICANCE: The presence of calpain and calpain-like molecules in a wide range of organisms suggests that these proteins could be necessary for basic cellular functions. Herein, we demonstrated the effects of MDL28170 in crucial steps of the T. cruzi life cycle, such as attachment to the insect midgut and metacyclogenesis, as well as in parasite viability and morphology. Together with our previous findings, these results help to shed some light on the functions of T. cruzi calpains. Considering the potential roles of

  1. The MASP family of Trypanosoma cruzi: changes in gene expression and antigenic profile during the acute phase of experimental infection.

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    Sara Lopes dos Santos

    Full Text Available Trypanosoma cruzi is the etiological agent of Chagas disease, a debilitating illness that affects millions of people in the Americas. A major finding of the T. cruzi genome project was the discovery of a novel multigene family composed of approximately 1,300 genes that encode mucin-associated surface proteins (MASPs. The high level of polymorphism of the MASP family associated with its localization at the surface of infective forms of the parasite suggests that MASP participates in host-parasite interactions. We speculate that the large repertoire of MASP sequences may contribute to the ability of T. cruzi to infect several host cell types and/or participate in host immune evasion mechanisms.By sequencing seven cDNA libraries, we analyzed the MASP expression profile in trypomastigotes derived from distinct host cells and after sequential passages in acutely infected mice. Additionally, to investigate the MASP antigenic profile, we performed B-cell epitope prediction on MASP proteins and designed a MASP-specific peptide array with 110 putative epitopes, which was screened with sera from acutely infected mice.We observed differential expression of a few MASP genes between trypomastigotes derived from epithelial and myoblast cell lines. The more pronounced MASP expression changes were observed between bloodstream and tissue-culture trypomastigotes and between bloodstream forms from sequential passages in acutely infected mice. Moreover, we demonstrated that different MASP members were expressed during the acute T. cruzi infection and constitute parasite antigens that are recognized by IgG and IgM antibodies. We also found that distinct MASP peptides could trigger different antibody responses and that the antibody level against a given peptide may vary after sequential passages in mice. We speculate that changes in the large repertoire of MASP antigenic peptides during an infection may contribute to the evasion of host immune responses during the

  2. The Complement System: A Prey of Trypanosoma cruzi

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    Kárita C. F. Lidani

    2017-04-01

    Full Text Available Trypanosoma cruzi is a protozoan parasite known to cause Chagas disease (CD, a neglected sickness that affects around 6–8 million people worldwide. Originally, CD was mainly found in Latin America but more recently, it has been spread to countries in North America, Asia, and Europe due the international migration from endemic areas. Thus, at present CD represents an important concern of global public health. Most of individuals that are infected by T. cruzi may remain in asymptomatic form all lifelong, but up to 40% of them will develop cardiomyopathy, digestive mega syndromes, or both. The interaction between the T. cruzi infective forms and host-related immune factors represents a key point for a better understanding of the physiopathology of CD. In this context, the complement, as one of the first line of host defense against infection was shown to play an important role in recognizing T. cruzi metacyclic trypomastigotes and in controlling parasite invasion. The complement consists of at least 35 or more plasma proteins and cell surface receptors/regulators, which can be activated by three pathways: classical (CP, lectin (LP, and alternative (AP. The CP and LP are mainly initiated by immune complexes or pathogen-associated molecular patterns (PAMPs, respectively, whereas AP is spontaneously activated by hydrolysis of C3. Once activated, several relevant complement functions are generated which include opsonization and phagocytosis of particles or microorganisms and cell lysis. An important step during T. cruzi infection is when intracellular trypomastigotes are release to bloodstream where they may be target by complement. Nevertheless, the parasite uses a sequence of events in order to escape from complement-mediated lysis. In fact, several T. cruzi molecules are known to interfere in the initiation of all three pathways and in the assembly of C3 convertase, a key step in the activation of complement. Moreover, T. cruzi promotes secretion

  3. Efficacy of 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinone derivatives against different Trypanosoma cruzi discrete type units: Identification of a promising hit compound.

    Science.gov (United States)

    Lara, L S; Moreira, C S; Calvet, C M; Lechuga, G C; Souza, R S; Bourguignon, S C; Ferreira, V F; Rocha, D; Pereira, M C S

    2018-01-20

    The limited efficacy of benznidazole (Bz) indicated by failures of current Phase II clinical trials emphasizes the urgent need to identify new drugs with improved safety and efficacy for treatment of Chagas disease (CD). Herein, we analyzed the efficacy of a series of 2-hydroxy-3-phenylsulfanylmethyl-[1,4]-naphthoquinones against different Trypanosoma cruzi discrete type units (DTUs) of relevant clinical forms of CD. Cytotoxic and trypanocidal effect of naphthoquinone derivatives were assessed in mammalian cells, trypomastigotes and intracellular amastigotes using, luminescent assays (CellTiter-Glo and T. cruzi Dm28c-luciferase) and/or counting with a light microscope. Reactive oxygen species (ROS) production and intracellular targets of promising compounds were assessed with 2',7'-dichlorodihydrofluorescein diacetate (H 2 DCFDA) probe and ultrastructural analysis, respectively. ADMET properties were analyzed by in silico modeling. Most of the compounds showed low cytotoxic effect. Only two compounds (Compounds 2 and 11) had IC 50 values lower than Bz, showing higher susceptibility of bloodstream trypomastigotes. Compound 2 exhibited greater efficacy against trypomastigotes from different T. cruzi DTUs, even better than Bz against Brazil and CL strains. Ultrastructural analysis revealed changes in intracellular compartments, suggesting autophagy as one possible mechanism of action. Oxidative stress, induced by Compound 2, resulted in elevated level of ROS, leading to parasite death. Compound 2 was also effective against intracellular amastigotes, showing high selectivity index. ADMET analysis predicted good oral bioavailability, reduced drug metabolism and no carcinogenic potential for Compound 2. The data highlight Compound 2 as a hit compound and stimulate further structural and pharmacological optimization to potentiate its trypanocidal activity and selectivity. Copyright © 2017. Published by Elsevier Masson SAS.

  4. Transcriptomic analysis reveals metabolic switches and surface remodeling as key processes for stage transition in Trypanosoma cruzi

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    Luisa Berná

    2017-03-01

    Full Text Available American trypanosomiasis is a chronic and endemic disease which affects millions of people. Trypanosoma cruzi, its causative agent, has a life cycle that involves complex morphological and functional transitions, as well as a variety of environmental conditions. This requires a tight regulation of gene expression, which is achieved mainly by post-transcriptional regulation. In this work we conducted an RNAseq analysis of the three major life cycle stages of T. cruzi: amastigotes, epimastigotes and trypomastigotes. This analysis allowed us to delineate specific transcriptomic profiling for each stage, and also to identify those biological processes of major relevance in each state. Stage specific expression profiling evidenced the plasticity of T. cruzi to adapt quickly to different conditions, with particular focus on membrane remodeling and metabolic shifts along the life cycle. Epimastigotes, which replicate in the gut of insect vectors, showed higher expression of genes related to energy metabolism, mainly Krebs cycle, respiratory chain and oxidative phosphorylation related genes, and anabolism related genes associated to nucleotide and steroid biosynthesis; also, a general down-regulation of surface glycoprotein coding genes was seen at this stage. Trypomastigotes, living extracellularly in the bloodstream of mammals, express a plethora of surface proteins and signaling genes involved in invasion and evasion of immune response. Amastigotes mostly express membrane transporters and genes involved in regulation of cell cycle, and also express a specific subset of surface glycoprotein coding genes. In addition, these results allowed us to improve the annotation of the Dm28c genome, identifying new ORFs and set the stage for construction of networks of co-expression, which can give clues about coded proteins of unknown functions.

  5. Ebi3 Prevents Trypanosoma cruzi-Induced Myocarditis by Dampening IFN-γ-Driven Inflammation

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    Tiago Silva Medina

    2017-09-01

    Full Text Available The identification of anti-inflammatory mediators can reveal important targetable molecules capable of counterbalancing Trypanosoma cruzi-induced myocarditis. Composed of Ebi3 and IL-27p28 subunits, IL-27 is produced by myeloid cells and is able to suppress inflammation by inducing IL-10-producing Tr1 cells, thus emerging as a potential candidate to ameliorate cardiac inflammation induced by T. cruzi. Although IL-27 has been extensively characterized as a suppressive cytokine that prevents liver immunopathogenesis after T. cruzi infection, the mechanisms underlying its effects on T. cruzi-induced myocarditis remain largely unknown. Here, wild-type (WT and Ebi3-deficient animals were intraperitoneally infected with trypomastigotes of T. cruzi Y strain and used to evaluate the potential anti-inflammatory properties of Ebi3 during T. cruzi infection. The survival rates of mice were daily recorded, the frequency of inflammatory cells was analyzed by flow cytometry and inflammatory mediators were measured by ELISA, real-time PCR and PCR array. We reported that T. cruzi-induced myocarditis was prevented by Ebi3. Stressors mainly recognized by TLR2 and TLR4 receptors on myeloid cells were essential to trigger IL-27p28 production. In addition, Ebi3 regulated IFN-γ-mediated myocarditis by promoting an anti-inflammatory environment through IL-10, which was most likely produced by Tr1 cells rather than classical regulatory T cells (Tregs, in the heart tissue of T. cruzi-infected animals. Furthermore, in vivo IFN-γ blockade ameliorated the host survival without compromising the parasite control in the bloodstream. In humans, IL-27p28 was correlated with cardiac protection during Chagas disease. Patients with mild clinical forms of the disease produced high levels of IL-27p28, whereas lower levels were found in those with severe forms. In addition, polymorphic sites at Ebi3 gene were associated with severe cardiomyopathy in patients with Chagas disease

  6. Ebi3 Prevents Trypanosoma cruzi-Induced Myocarditis by Dampening IFN-γ-Driven Inflammation

    Science.gov (United States)

    Medina, Tiago Silva; Oliveira, Gabriela Gonçalves; Silva, Maria Cláudia; David, Bruna Araújo; Silva, Grace Kelly; Fonseca, Denise Morais; Sesti-Costa, Renata; Frade, Amanda Farage; Baron, Monique Andrade; Ianni, Barbara; Pereira, Alexandre Costa; Chevillard, Christophe; Cunha-Neto, Edécio; Marin-Neto, José Antonio; Silva, João Santana

    2017-01-01

    The identification of anti-inflammatory mediators can reveal important targetable molecules capable of counterbalancing Trypanosoma cruzi-induced myocarditis. Composed of Ebi3 and IL-27p28 subunits, IL-27 is produced by myeloid cells and is able to suppress inflammation by inducing IL-10-producing Tr1 cells, thus emerging as a potential candidate to ameliorate cardiac inflammation induced by T. cruzi. Although IL-27 has been extensively characterized as a suppressive cytokine that prevents liver immunopathogenesis after T. cruzi infection, the mechanisms underlying its effects on T. cruzi-induced myocarditis remain largely unknown. Here, wild-type (WT) and Ebi3-deficient animals were intraperitoneally infected with trypomastigotes of T. cruzi Y strain and used to evaluate the potential anti-inflammatory properties of Ebi3 during T. cruzi infection. The survival rates of mice were daily recorded, the frequency of inflammatory cells was analyzed by flow cytometry and inflammatory mediators were measured by ELISA, real-time PCR and PCR array. We reported that T. cruzi-induced myocarditis was prevented by Ebi3. Stressors mainly recognized by TLR2 and TLR4 receptors on myeloid cells were essential to trigger IL-27p28 production. In addition, Ebi3 regulated IFN-γ-mediated myocarditis by promoting an anti-inflammatory environment through IL-10, which was most likely produced by Tr1 cells rather than classical regulatory T cells (Tregs), in the heart tissue of T. cruzi-infected animals. Furthermore, in vivo IFN-γ blockade ameliorated the host survival without compromising the parasite control in the bloodstream. In humans, IL-27p28 was correlated with cardiac protection during Chagas disease. Patients with mild clinical forms of the disease produced high levels of IL-27p28, whereas lower levels were found in those with severe forms. In addition, polymorphic sites at Ebi3 gene were associated with severe cardiomyopathy in patients with Chagas disease. Collectively, we

  7. Rhodium-catalyzed C-H bond activation for the synthesis of quinonoid compounds: Significant Anti-Trypanosoma cruzi activities and electrochemical studies of functionalized quinones.

    Science.gov (United States)

    Jardim, Guilherme A M; Silva, Thaissa L; Goulart, Marilia O F; de Simone, Carlos A; Barbosa, Juliana M C; Salomão, Kelly; de Castro, Solange L; Bower, John F; da Silva Júnior, Eufrânio N

    2017-08-18

    Thirty four halogen and selenium-containing quinones, synthesized by rhodium-catalyzed C-H bond activation and palladium-catalyzed cross-coupling reactions, were evaluated against bloodstream trypomastigotes of T. cruzi. We have identified fifteen compounds with IC 50 /24 h values of less than 2 μM. Electrochemical studies on A-ring functionalized naphthoquinones were also performed aiming to correlate redox properties with trypanocidal activity. For instance, (E)-5-styryl-1,4-naphthoquinone 59 and 5,8-diiodo-1,4-naphthoquinone 3, which are around fifty fold more active than the standard drug benznidazole, are potential derivatives for further investigation. These compounds represent powerful new agents useful in Chagas disease therapy. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  8. Differential gene expression during Trypanosoma cruzi metacyclogenesis

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    Marco Aurelio Krieger

    1999-09-01

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

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

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    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.

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

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    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. Structural Basis of the Interaction of a Trypanosoma cruzi Surface Molecule Implicated in Oral Infection with Host Cells and Gastric Mucin

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    Cortez, Cristian; Yoshida, Nobuko; Bahia, Diana; Sobreira, Tiago J.P.

    2012-01-01

    Host cell invasion and dissemination within the host are hallmarks of virulence for many pathogenic microorganisms. As concerns Trypanosoma cruzi, which causes Chagas disease, the insect vector-derived metacyclic trypomastigotes (MT) initiate infection by invading host cells, and later blood trypomastigotes disseminate to diverse organs and tissues. Studies with MT generated in vitro and tissue culture-derived trypomastigotes (TCT), as counterparts of insect-borne and bloodstream parasites, have implicated members of the gp85/trans-sialidase superfamily, MT gp82 and TCT Tc85-11, in cell invasion and interaction with host factors. Here we analyzed the gp82 structure/function characteristics and compared them with those previously reported for Tc85-11. One of the gp82 sequences identified as a cell binding site consisted of an α-helix, which connects the N-terminal β-propeller domain to the C-terminal β-sandwich domain where the second binding site is nested. In the gp82 structure model, both sites were exposed at the surface. Unlike gp82, the Tc85-11 cell adhesion sites are located in the N-terminal β-propeller region. The gp82 sequence corresponding to the epitope for a monoclonal antibody that inhibits MT entry into target cells was exposed on the surface, upstream and contiguous to the α-helix. Located downstream and close to the α-helix was the gp82 gastric mucin binding site, which plays a central role in oral T. cruzi infection. The sequences equivalent to Tc85-11 laminin-binding sites, which have been associated with the parasite ability to overcome extracellular matrices and basal laminae, was poorly conserved in gp82, compatible with its reduced capacity to bind laminin. Our study indicates that gp82 is structurally suited for MT to initiate infection by the oral route, whereas Tc85-11, with its affinity for laminin, would facilitate the parasite dissemination through diverse organs and tissues. PMID:22860068

  12. Histopathologic identification of Trypanosoma cruzi (Chagas' encephalitis in an AIDS patient

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    Dimath Alyemni

    2017-03-01

    Full Text Available Trypanosoma cruzi (Chagas' encephalitis is an uncommon manifestation of T. cruzi infection, typically seen in immunocompromised patients. Encephalitis results from the reactivation of chronic infection predominately in individuals from endemic areas. Increased awareness of this complication is essential especially with increased migration of patients from endemic areas with concomitant HIV infection. Here we report a case of Chagas' encephalitis in an AIDS patient from Mexico in which there was no evidence of acute serologic, CSF, or blood infection by T. cruzi trypomastigotes.

  13. 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.

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

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    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.

  15. 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.

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

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    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.

  17. 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.

  18. 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.

  19. Trypanosoma cruzi: effects of azadirachtin and ecdysone on the dynamic development in Rhodnius prolixus larvae.

    Science.gov (United States)

    Cortez, M R; Provençano, A; Silva, C E; Mello, C B; Zimmermann, L T; Schaub, G A; Garcia, E S; Azambuja, P; Gonzalez, M S

    2012-07-01

    The effects of azadirachtin and ecdysone on the Trypanosoma cruzi population in the Rhodnius prolixus gut were investigated. T. cruzi were rarely found in the gut compartments of azadirachtin-treated larvae. High parasite numbers were observed in the stomach of the control and ecdysone groups until 10 days after treatment and in the small intestine and rectum until 25 days after treatment. High percentages of round forms developed in the stomachs of all groups, whereas azadirachtin blocked the development of protozoan intermediate forms. This effect was counteracted by ecdysone therapy. In the small intestine and rectum, epimastigotes predominated for all groups, but more of their intermediates developed in the control and ecdysone groups. Azadirachtin supported the development of round forms and their intermediates into trypomastigotes. In the rectum, trypomastigotes did not develop in the azadirachtin group and developed much later after ecdysone therapy. The parallel between the effects of azadirachtin and ecdysone on the host and parasite development is discussed on the basis of the present results because ecdysone appears to act directly or indirectly in determining the synchronic development of T. cruzi forms from round to epimastigotes, but not metacyclic trypomastigotes, in the invertebrate vector. Copyright © 2012 Elsevier Inc. All rights reserved.

  20. Induction of IL-12 Production in Human Peripheral Monocytes by Trypanosoma cruzi Is Mediated by Glycosylphosphatidylinositol-Anchored Mucin-Like Glycoproteins and Potentiated by IFN-γ and CD40-CD40L Interactions

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    Lúcia Cristina Jamli Abel

    2014-01-01

    Full Text Available Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi, is characterized by immunopathology driven by IFN-γ secreting Th1-like T cells. T. cruzi has a thick coat of mucin-like glycoproteins covering its surface, which plays an important role in parasite invasion and host immunomodulation. It has been extensively described that T. cruzi or its products—like GPI anchors isolated from GPI-anchored mucins from the trypomastigote life cycle stage (tGPI-mucins—are potent inducers of proinflammatory responses (i.e., cytokines and NO production by IFN-γ primed murine macrophages. However, little is known about whether T. cruzi or GPI-mucins exert a similar action in human cells. We therefore decided to further investigate the in vitro cytokine production profile from human mononuclear cells from uninfected donors exposed to T. cruzi as well as tGPI-mucins. We observed that both living T. cruzi trypomastigotes and tGPI-mucins are potent inducers of IL-12 by human peripheral blood monocytes and this effect depends on CD40-CD40L interaction and IFN-γ. Our findings suggest that the polarized T1-type cytokine profile seen in T. cruzi infected patients might be a long-term effect of IL-12 production induced by lifelong exposure to T. cruzi tGPI-mucins.

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

    International Nuclear Information System (INIS)

    Nogueira, N.; Chaplan, S.; Tydings, J.D.; Unkeless, J.; Cohn, Z.

    1981-01-01

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

  2. Polyclonal antibodies for the detection of Trypanosoma cruzi circulating antigens.

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    Edith S Málaga-Machaca

    2017-11-01

    Full Text Available Detection of Trypanosoma cruzi antigens in clinical samples is considered an important diagnostic tool for Chagas disease. The production and use of polyclonal antibodies may contribute to an increase in the sensitivity of immunodiagnosis of Chagas disease.Polyclonal antibodies were raised in alpacas, rabbits, and hens immunized with trypomastigote excreted-secreted antigen, membrane proteins, trypomastigote lysate antigen and recombinant 1F8 to produce polyclonal antibodies. Western blot analysis was performed to determine specificity of the developed antibodies. An antigen capture ELISA of circulating antigens in serum, plasma and urine samples was developed using IgY polyclonal antibodies against T. cruzi membrane antigens (capture antibody and IgG from alpaca raised against TESA. A total of 33 serum, 23 plasma and 9 urine samples were analyzed using the developed test. Among serum samples, compared to serology, the antigen capture ELISA tested positive in 55% of samples. All plasma samples from serology positive subjects were positive in the antigen capture ELISA. All urine positive samples had corresponding plasma samples that were also positive when tested by the antigen capture ELISA.Polyclonal antibodies are useful for detection of circulating antigens in both the plasma and urine of infected individuals. Detection of antigens is direct evidence of the presence of the parasite, and could be a better surrogate of current infection status.

  3. Biological Parameters and Molecular Markers of Clone CL Brener - The Reference Organism of the Trypanosoma cruzi Genome Project

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    Bianca Zingales

    1997-11-01

    Full Text Available Clone CL Brener is the reference organism used in the Trypanosoma cruzi Genome Project. Some biological parameters of CL Brener were determined: (a the doubling time of epimastigote forms cultured in liver infusion-tryptose (LIT medium at 28oC is 58±13 hr; (b differentiation of epimastigotes to metacyclic trypomastigotes is obtained by incubation in LIT-20% Grace´s medium; (c trypomastigotes infect mammalian cultured cells and perform the complete intracellular cycle at 33 and 37oC; (d blood forms are highly infective to mice; (e blood forms are susceptible to nifurtimox and benznidazole. The molecular typing of CL Brener has been determined: (a isoenzymatic profiles are characteristic of zymodeme ZB; (b PCR amplification of a 24Sa ribosomal RNA sequence indicates it belongs to T. cruzi lineage 1; (c schizodeme, randomly amplified polymorphic DNA (RAPD and DNA fingerprinting analyses were performed

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

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    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.

  5. 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.

  6. Trypanosoma cruzi: partial prevention of the natural infection of guinea pigs with a killed parasite vaccine.

    Science.gov (United States)

    Basombrio, M A

    1990-07-01

    Guinea pigs are natural reservoirs of Chagas' disease. Domestic breeding and local trade of these animals are common practices among andean communities in South America. Infection by Trypanosoma cruzi occurs when the animals live in triatomine-infested houses or yards. The preventive effect of a vaccine consisting of cultured T. cruzi killed by freezing and thawing plus saponin was tested both in mice and in the guinea pig ecosystem. Resistance against T. cruzi challenge in mice was improved by increasing the trypomastigote/epimastigote ratio in live attenuated vaccines but not in killed parasite vaccines. Although the killing of attenuated parasites sharply reduced their immunogenicity for mice, a protective effect against natural T. cruzi infection was detected in guinea pigs. A total of 88 guinea pigs were vaccinated in four intradermal sites on three occasions. Eighty controls received similar inoculations of culture medium plus saponin. All animals were kept in a triatomine-infested yard. Parasitemia was studied with the capillary microhematocrit method. After an exposure time averaging 4 months, natural T. cruzi infection occurred in 55% (44/80) of the controls and in 33% (29/88) of the vaccinated group (P less than 0.01). The number of highly parasitemic guinea pigs was also significantly decreased (6/80 vs 0/88, P less than 0.01). Thus, immunizing protocols which are only partially protective against artificial callenge with T. cruzi may nevertheless constrain the exchange of parasites between natural hosts and vectors.

  7. The regulation of autophagy differentially affects Trypanosoma cruzi metacyclogenesis.

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    María Cristina Vanrell

    2017-11-01

    Full Text Available Autophagy is a cellular process required for the removal of aged organelles and cytosolic components through lysosomal degradation. All types of eukaryotic cells from yeasts to mammalian cells have the machinery to activate autophagy as a result of many physiological and pathological situations. The most frequent stimulus of autophagy is starvation and the result, in this case, is the fast generation of utilizable food (e.g. amino acids and basic nutrients to maintain the vital biological processes. In some organisms, starvation also triggers other associated processes such as differentiation. The protozoan parasite Trypanosoma cruzi undergoes a series of differentiation processes throughout its complex life cycle. Although not all autophagic genes have been identified in the T. cruzi genome, previous works have demonstrated the presence of essential autophagic-related proteins. Under starvation conditions, TcAtg8, which is the parasite homolog of Atg8/LC3 in other organisms, is located in autophagosome-like vesicles. In this work, we have characterized the autophagic pathway during T. cruzi differentiation from the epimastigote to metacyclic trypomastigote form, a process called metacyclogenesis. We demonstrated that autophagy is stimulated during metacyclogenesis and that the induction of autophagy promotes this process. Moreover, with exception of bafilomycin, other classical autophagy modulators have similar effects on T. cruzi autophagy. We also showed that spermidine and related polyamines can positively regulate parasite autophagy and differentiation. We concluded that both polyamine metabolism and autophagy are key processes during T. cruzi metacyclogenesis that could be exploited as drug targets to avoid the parasite cycle progression.

  8. 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

  9. Interactions between 4-aminoquinoline and heme: Promising mechanism against Trypanosoma cruzi

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    Guilherme Curty Lechuga

    2016-12-01

    Full Text Available Chagas disease is a neglected tropical disease caused by the flagellated protozoan Trypanosoma cruzi. The current drugs used to treat this disease have limited efficacy and produce severe side effects. Quinolines, nitrogen heterocycle compounds that form complexes with heme, have a broad spectrum of antiprotozoal activity and are a promising class of new compounds for Chagas disease chemotherapy. In this study, we evaluated the activity of a series of 4-arylaminoquinoline-3-carbonitrile derivatives against all forms of Trypanosoma cruzi in vitro. Compound 1g showed promising activity against epimastigote forms when combined with hemin (IC50<1 μM, with better performance than benznidazole, the reference drug. This compound also inhibited the viability of trypomastigotes and intracellular amastigotes. The potency of 1g in combination with heme was enhanced against epimastigotes and trypomastigotes, suggesting a similar mechanism of action that occurs in Plasmodium spp. The addition of hemin to the culture medium increased trypanocidal activity of analog 1g without changing the cytotoxicity of the host cell, reaching an IC50 of 11.7 μM for trypomastigotes. The mechanism of action was demonstrated by the interaction of compound 1g with hemin in solution and prevention of heme peroxidation. Compound 1g and heme treatment induced alterations of the mitochondrion-kinetoplast complex in epimastigotes and trypomastigotes and also, accumulation of electron-dense deposits in amastigotes as visualized by transmission electron microscopy. The trypanocidal activity of 4-aminoquinolines and the elucidation of the mechanism involving interaction with heme is a neglected field of research, given the parasite's lack of heme biosynthetic pathway and the importance of this cofactor for parasite survival and growth. The results of this study can improve and guide rational drug development and combination treatment strategies.

  10. Interactions between 4-aminoquinoline and heme: Promising mechanism against Trypanosoma cruzi.

    Science.gov (United States)

    Lechuga, Guilherme Curty; Borges, Júlio Cesar; Calvet, Claudia Magalhães; de Araújo, Humberto Pinheiro; Zuma, Aline Araujo; do Nascimento, Samara Braga; Motta, Maria Cristina Machado; Bernardino, Alice Maria Rolim; Pereira, Mirian Claudia de Souza; Bourguignon, Saulo Cabral

    2016-12-01

    Chagas disease is a neglected tropical disease caused by the flagellated protozoan Trypanosoma cruzi. The current drugs used to treat this disease have limited efficacy and produce severe side effects. Quinolines, nitrogen heterocycle compounds that form complexes with heme, have a broad spectrum of antiprotozoal activity and are a promising class of new compounds for Chagas disease chemotherapy. In this study, we evaluated the activity of a series of 4-arylaminoquinoline-3-carbonitrile derivatives against all forms of Trypanosoma cruzi in vitro. Compound 1g showed promising activity against epimastigote forms when combined with hemin (IC50<1 μM), with better performance than benznidazole, the reference drug. This compound also inhibited the viability of trypomastigotes and intracellular amastigotes. The potency of 1g in combination with heme was enhanced against epimastigotes and trypomastigotes, suggesting a similar mechanism of action that occurs in Plasmodium spp. The addition of hemin to the culture medium increased trypanocidal activity of analog 1g without changing the cytotoxicity of the host cell, reaching an IC50 of 11.7 μM for trypomastigotes. The mechanism of action was demonstrated by the interaction of compound 1g with hemin in solution and prevention of heme peroxidation. Compound 1g and heme treatment induced alterations of the mitochondrion-kinetoplast complex in epimastigotes and trypomastigotes and also, accumulation of electron-dense deposits in amastigotes as visualized by transmission electron microscopy. The trypanocidal activity of 4-aminoquinolines and the elucidation of the mechanism involving interaction with heme is a neglected field of research, given the parasite's lack of heme biosynthetic pathway and the importance of this cofactor for parasite survival and growth. The results of this study can improve and guide rational drug development and combination treatment strategies. Copyright © 2016 The Authors. Published by Elsevier

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

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

    2014-08-22

    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. The following EOs were evaluated on T. cruzi epimastigote forms: Cinnamomum verum, Citrus limon, Cymbopogon nardus, Corymbia citriodora, Eucalyptus globulus, Eugenia uniflora, Myrocarpus frondosus, and Rosmarinus officinalis. Inhibitory activity against T. cruzi (IC50/24 h) and cytotoxicity against Vero cells (CC50/24 h) were evaluated by the MTT assay. The EO of C. verum was selected for further evaluation against trypomastigotes and intracellular amastigotes, as well as on parasite metacyclogenesis. Constituents of C. verum EO were identified by GC-MS. One-way ANOVA statistical analysis was performed with GraphPad version 5.01. Cinnamomum verum EO was the most effective against T. cruzi epimastigotes (IC50/24 h = 24.13 μg/ml), followed by Myrocarpus frondosus (IC50/24 h = 60.87 μg/ml) and Eugenia uniflora (IC50/24 h = 70 μg/ml). The EOs of C. citriodora, E. globulus, and R. officinalis showed no activity at concentrations up to 300 μg/ml. Incubation of T. cruzi metacyclic trypomastigotes and intracellular amastigotes with C. verum EO resulted in IC50/24 h values of 5.05 μg/ml and 20 μg/ml, respectively. Therefore, trypomastigotes are more susceptible than epimastigotes, with selectivity index (SI) about 4.7-fold higher (9.78 and 2.05, respectively). Analysis of C. verum EO by GC-MS showed mainly (E)-cinnamaldehyde (81.52%) and eugenol (16.68%). C. verum essential oil is effective against T. cruzi (epimastigotes, trypomastigotes and amastigotes) and interferes with the parasite differentiation process in vitro. Thus, it represents a strong candidate for further studies to improve its activity on pathogenic trypanosomatids.

  12. The anticancer drug tamoxifen is active against Trypanosoma cruzi in vitro but ineffective in the treatment of the acute phase of Chagas disease in mice

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    Danilo Ciccone Miguel

    2010-11-01

    Full Text Available The activity of the antineoplastic drug tamoxifen was evaluated against Trypanosoma cruzi. In vitro activity was determined against epimastigote, trypomastigote and amastigote forms of CL14, Y and Y benznidazole resistant T. cruzi strains. Regardless of the strain used, the drug was active against all life-cycle stages of the parasite with a half maximal effective concentration ranging from 0.7-17.9 µM. Two experimental models of acute Chagas disease were used to evaluate the in vivo efficacy of treatment with tamoxifen. No differences in parasitemia and mortality were observed between control mock-treated and tamoxifen-treated mice.

  13. 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.

  14. Structural and functional analysis of a platelet-activating lysophosphatidylcholine of Trypanosoma cruzi.

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    Felipe Gazos-Lopes

    2014-08-01

    Full Text Available Trypanosoma cruzi is the causative agent of the life-threatening Chagas disease, in which increased platelet aggregation related to myocarditis is observed. Platelet-activating factor (PAF is a potent intercellular lipid mediator and second messenger that exerts its activity through a PAF-specific receptor (PAFR. Previous data from our group suggested that T. cruzi synthesizes a phospholipid with PAF-like activity. The structure of T. cruzi PAF-like molecule, however, remains elusive.Here, we have purified and structurally characterized the putative T. cruzi PAF-like molecule by electrospray ionization-tandem mass spectrometry (ESI-MS/MS. Our ESI-MS/MS data demonstrated that the T. cruzi PAF-like molecule is actually a lysophosphatidylcholine (LPC, namely sn-1 C18:1(delta 9-LPC. Similar to PAF, the platelet-aggregating activity of C18:1-LPC was abrogated by the PAFR antagonist, WEB 2086. Other major LPC species, i.e., C16:0-, C18:0-, and C18:2-LPC, were also characterized in all T. cruzi stages. These LPC species, however, failed to induce platelet aggregation. Quantification of T. cruzi LPC species by ESI-MS revealed that intracellular amastigote and trypomastigote forms have much higher levels of C18:1-LPC than epimastigote and metacyclic trypomastigote forms. C18:1-LPC was also found to be secreted by the parasite in extracellular vesicles (EV and an EV-free fraction. A three-dimensional model of PAFR was constructed and a molecular docking study was performed to predict the interactions between the PAFR model and PAF, and each LPC species. Molecular docking data suggested that, contrary to other LPC species analyzed, C18:1-LPC is predicted to interact with the PAFR model in a fashion similar to PAF.Taken together, our data indicate that T. cruzi synthesizes a bioactive C18:1-LPC, which aggregates platelets via PAFR. We propose that C18:1-LPC might be an important lipid mediator in the progression of Chagas disease and its biosynthesis could

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

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    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

  16. Developmentally regulated expression by Trypanosoma cruzi of molecules that accelerate the decay of complement C3 convertases

    International Nuclear Information System (INIS)

    Rimoldi, M.T.; Sher, A.; Heiny, A.; Lituchy, A.; Hammer, C.H.; Joiner, K.

    1988-01-01

    The authors recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 99 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results suggested that CMT and tissue-culture-derived trypomastigotes (TCT), which also activate the alternative pathway poorly, might produce a molecule capable of interfering with factor B binding to C3b. They now demonstrate that CMT and TCT lysates, as well as molecules spontaneously shed from CMT and TCT but not Epi, accelerate decay of 125 I-labeled factor Bb from the alternative-pathway C3 convertase (C3bBb) assembled on zymosan or Epi and also accelerate decay of the classical-pathway C3 convertase (C4b2a) on sheep erythrocytes. Parasites metabolically labeled with [ 35 S]methionine spontaneously shed a limited number of radioactive components, ranging in molecular mass from 86 to 155 kDa for trypomastigotes and 25 to 80 kDa for Epi. Decay-accelerating activity within supernatants is inactivated by papain and is coeluted with 35 S-containing polypeptides on FPLC anion-exchange chromatography, suggesting that the active constituents are protein molecules. Molecules with decay-accelerating activity may explain the developmentally regulated resistance to complement-mediated lysis in infective and vertebrate stages for T. cruzi life cycle

  17. Molecular basis of mammalian cell invasion by Trypanosoma cruzi

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    Nobuko Yoshida

    2006-03-01

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

  18. Genetically different isolates of Trypanosoma cruzi elicit different infection dynamics in raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana).

    Science.gov (United States)

    Roellig, Dawn M; Ellis, Angela E; Yabsley, Michael J

    2009-12-01

    Trypanosoma cruzi is a genetically and biologically diverse species. In the current study we determined T. cruzi infection dynamics in two common North American reservoirs, Virginia opossums (Didelphis virginiana) and raccoons (Procyon lotor). Based on previous molecular and culture data from naturally-exposed animals, we hypothesised that raccoons would have a longer patent period than opossums, and raccoons would be competent reservoirs for both genotypes T. cruzi I (TcI) and TcIIa, while opossums would only serve as hosts for TcI. Individuals (n=2 or 3) of each species were inoculated with 1x10(6) culture-derived T. cruzi trypomastigotes of TcIIa (North American (NA) - raccoon), TcI (NA - opossum), TcIIb (South American - human), or both TcI and TcIIa. Parasitemias in opossums gradually increased and declined rapidly, whereas parasitemias peaked sooner in raccoons and they maintained relatively high parasitemia for 5weeks. Raccoons became infected with all three T. cruzi strains, while opossums only became infected with TcI and TcIIb. Although opossums were susceptible to TcIIb, infection dynamics were dramatically different compared with TcI. Opossums inoculated with TcIIb seroconverted, but parasitemia duration was short and only detectable by PCR. In addition, raccoons seroconverted sooner (3-7days post inoculation) than opossums (10days post inoculation). These data suggest that infection dynamics of various T. cruzi strains can differ considerably in different wildlife hosts.

  19. 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

  20. Enhancing effects of gamma interferon on phagocytic cell association with and killing of Trypanosoma cruzi

    Science.gov (United States)

    Wirth, J. J.; Kierszenbaum, F.; Sonnenfeld, G.; Zlotnik, A.

    1985-01-01

    Results are reported from a study of the influence gamma interferon (GIFN) and interleukin 2 (IL2) have on the capability of P388D1 cells and mouse resident peritoneal macrophages (MPM) to attach to the blood-resident parasites Trypanosoma cruzi and kill them. Cultures of trypomastigote forms of the Tulahuen strain of T. cruzi grown in bovine serum were introduced into peritoneal cells of mice, along with P388D1 cells incubated with GIFN, IL2 and both. Control cells were also maintained. Statistical analysis were then performed on data on counts of the number of dead T. Cruzi cells. The GIFN enhanced the interaction of MPM and P388D1 cells with the surface of T. Cruzi, provided the interaction was given over 12 hr to take place. A depression of the cytotoxicity of P388D1 cells was attributed to mediation by H2O2, an effect partially offset by incubation with the lymphokine GIFN.

  1. Moderate physical exercise protects myenteric metabolically more active neurons in mice infected with Trypanosoma cruzi.

    Science.gov (United States)

    Moreira, Neide Martins; de Moraes, Solange Marta Franzói; Dalálio, M M O; Gomes, Mônica Lúcia; Sant'ana, D M G; de Araújo, Silvana Marques

    2014-02-01

    Trypanosoma cruzi causes neuronal myenteric depopulation compromising intestinal function. The purpose of this study was to evaluate the influence of moderate physical exercise on NADH diaphorase (NADH-d)-positive neurons in the myenteric plexus and intestinal wall of the colon in mice infected with T. cruzi. Forty 30-day-old male Swiss mice were divided into the following groups: trained infected (TI), sedentary infected (SI), trained control (TC), and sedentary control. The TC and TI groups were subjected to a moderate physical exercise program on a treadmill for 8 weeks. Three days after finishing physical exercise, the TI and SI groups were intraperitoneally inoculated with 1,300 blood trypomastigotes of the Y strain of Trypanosoma cruzi. Parasitemia was evaluated from days 4 to 61 after inoculation. On day 75 of infection, myenteric neurons in the colon were quantified (NADH-d), and inflammatory foci were counted. Tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) levels were evaluated in plasma. The results were compared using analysis of variance and the Kruskal-Wallis test at a 5 % significance level. Moderate physical exercise reduced the parasite peak on day 8 of infection (p = 0.0132) and total parasitemia (p = 0.0307). It also prevented neuronal depopulation (p  0.05). These results reinforce the therapeutic benefits of moderate physical exercise for T. cruzi infection.

  2. Limited antigenic variation in the Trypanosoma cruzi candidate vaccine antigen TSA-1.

    Science.gov (United States)

    Knight, J M; Zingales, B; Bottazzi, M E; Hotez, P; Zhan, B

    2014-12-01

    Chagas disease (American trypanosomiasis caused by Trypanosoma cruzi) is one of the most important neglected tropical diseases in the Western Hemisphere. The toxicities and limited efficacies of current antitrypanosomal drugs have prompted a search for alternative technologies such as a therapeutic vaccine comprised of T. cruzi antigens, including a recombinant antigen encoding the N-terminal 65 kDa portion of Trypomastigote surface antigen-1 (TSA-1). With at least six known genetically distinct T. cruzi lineages, variability between the different lineages poses a unique challenge for the development of broadly effective therapeutic vaccine. The variability across the major lineages in the current vaccine candidate antigen TSA-1 has not previously been addressed. To assess the variation in TSA-1, we cloned and sequenced TSA-1 from several different T. cruzi strains representing three of the most clinically relevant lineages. Analysis of the different alleles showed limited variation in TSA-1 across the different strains and fit with the current theory for the evolution of the different lineages. Additionally, minimal variation in known antigenic epitopes for the HLA-A 02 allele suggests that interlineage variation in TSA-1 would not impair the range and efficacy of a vaccine containing TSA-1. © 2014 John Wiley & Sons Ltd.

  3. Expression and subcellular localization of kinetoplast-associated proteins in the different developmental stages of Trypanosoma cruzi

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    Cavalcanti Danielle

    2009-06-01

    Full Text Available Abstract Background The kinetoplast DNA (kDNA of trypanosomatids consists of an unusual arrangement of circular molecules catenated into a single network. The diameter of the isolated kDNA network is similar to that of the entire cell. However, within the kinetoplast matrix, the kDNA is highly condensed. Studies in Crithidia fasciculata showed that kinetoplast-associated proteins (KAPs are capable of condensing the kDNA network. However, little is known about the KAPs of Trypanosoma cruzi, a parasitic protozoon that shows distinct patterns of kDNA condensation during their complex morphogenetic development. In epimastigotes and amastigotes (replicating forms the kDNA fibers are tightly packed into a disk-shaped kinetoplast, whereas trypomastigotes (non-replicating present a more relaxed kDNA organization contained within a rounded structure. It is still unclear how the compact kinetoplast disk of epimastigotes is converted into a globular structure in the infective trypomastigotes. Results In this work, we have analyzed KAP coding genes in trypanosomatid genomes and cloned and expressed two kinetoplast-associated proteins in T. cruzi: TcKAP4 and TcKAP6. Such small basic proteins are expressed in all developmental stages of the parasite, although present a differential distribution within the kinetoplasts of epimastigote, amastigote and trypomastigote forms. Conclusion Several features of TcKAPs, such as their small size, basic nature and similarity with KAPs of C. fasciculata, are consistent with a role in DNA charge neutralization and condensation. Additionally, the differential distribution of KAPs in the kinetoplasts of distinct developmental stages of the parasite, indicate that the kDNA rearrangement that takes place during the T. cruzi differentiation process is accompanied by TcKAPs redistribution.

  4. Identification of three classes of heteroaromatic compounds with activity against intracellular Trypanosoma cruzi by chemical library screening.

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    Esther Bettiol

    Full Text Available The development of new drugs against Chagas disease is a priority since the currently available medicines have toxic effects, partial efficacy and are targeted against the acute phase of disease. At present, there is no drug to treat the chronic stage. In this study, we have optimized a whole cell-based assay for high throughput screening of compounds that inhibit infection of mammalian cells by Trypanosoma cruzi trypomastigotes. A 2000-compound chemical library was screened using a recombinant T. cruzi (Tulahuen strain expressing beta-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC(50: 54, 190 and 23 nM, respectively. Each of these three compounds presents a different mechanism of action on intracellular proliferation of T. cruzi amastigotes. CX1 shows strong trypanocidal activity, an essential characteristic for the development of drugs against the chronic stage of Chagas disease where parasites are found intracellular in a quiescent stage. NT1 has a trypanostatic effect, while PCH1 affects parasite division. The three compounds also show high activity against intracellular T. cruzi from the Y strain and against the related kinetoplastid species Leishmania major and L. amazonensis. Characterization of the anti-T. cruzi activity of molecules chemically related to the three library hits allowed the selection of two compounds with IC(50 values of 2 nM (PCH6 and CX2. These values are approximately 100 times lower than those of the medicines used in patients against T. cruzi. These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis.

  5. Identification of three classes of heteroaromatic compounds with activity against intracellular Trypanosoma cruzi by chemical library screening.

    Science.gov (United States)

    Bettiol, Esther; Samanovic, Marie; Murkin, Andrew S; Raper, Jayne; Buckner, Frederick; Rodriguez, Ana

    2009-01-01

    The development of new drugs against Chagas disease is a priority since the currently available medicines have toxic effects, partial efficacy and are targeted against the acute phase of disease. At present, there is no drug to treat the chronic stage. In this study, we have optimized a whole cell-based assay for high throughput screening of compounds that inhibit infection of mammalian cells by Trypanosoma cruzi trypomastigotes. A 2000-compound chemical library was screened using a recombinant T. cruzi (Tulahuen strain) expressing beta-galactosidase. Three hits were selected for their high activity against T. cruzi and low toxicity to host cells in vitro: PCH1, NT1 and CX1 (IC(50): 54, 190 and 23 nM, respectively). Each of these three compounds presents a different mechanism of action on intracellular proliferation of T. cruzi amastigotes. CX1 shows strong trypanocidal activity, an essential characteristic for the development of drugs against the chronic stage of Chagas disease where parasites are found intracellular in a quiescent stage. NT1 has a trypanostatic effect, while PCH1 affects parasite division. The three compounds also show high activity against intracellular T. cruzi from the Y strain and against the related kinetoplastid species Leishmania major and L. amazonensis. Characterization of the anti-T. cruzi activity of molecules chemically related to the three library hits allowed the selection of two compounds with IC(50) values of 2 nM (PCH6 and CX2). These values are approximately 100 times lower than those of the medicines used in patients against T. cruzi. These results provide new candidate molecules for the development of treatments against Chagas disease and leishmaniasis.

  6. Captopril increases the intensity of monocyte infection by Trypanosoma cruzi and induces human T helper type 17 cells.

    Science.gov (United States)

    Coelho dos Santos, J S; Menezes, C A S; Villani, F N A; Magalhães, L M D; Scharfstein, J; Gollob, K J; Dutra, W O

    2010-12-01

    The anti-hypertensive drug captopril is used commonly to reduce blood pressure of patients with severe forms of Chagas disease, a cardiomyopathy caused by chronic infection with the intracellular protozoan Trypanosoma cruzi. Captopril acts by inhibiting angiotensin-converting enzyme (ACE), the vasopressor metallopeptidase that generates angiotensin II and promotes the degradation of bradykinin (BK). Recent studies in mice models of Chagas disease indicated that captopril can potentiate the T helper type 1 (Th1)-directing natural adjuvant property of BK. Equipped with kinin-releasing cysteine proteases, T. cruzi trypomastigotes were shown previously to invade non-professional phagocytic cells, such as human endothelial cells and murine cardiomyocytes, through the signalling of G protein-coupled bradykinin receptors (B(2) KR). Monocytes are also parasitized by T. cruzi and these cells are known to be important for the host immune response during infection. Here we showed that captopril increases the intensity of T. cruzi infection of human monocytes in vitro. The increased parasitism was accompanied by up-regulated expression of ACE in human monocytes. While T. cruzi infection increased the expression of interleukin (IL)-10 by monocytes significantly, compared to uninfected cells, T. cruzi infection in association with captopril down-modulated IL-10 expression by the monocytes. Surprisingly, studies with peripheral blood mononuclear cells revealed that addition of the ACE inhibitor in association with T. cruzi increased expression of IL-17 by CD4(+) T cells in a B(2) KR-dependent manner. Collectively, our results suggest that captopril might interfere with host-parasite equilibrium by enhancing infection of monocytes, decreasing the expression of the modulatory cytokine IL-10, while guiding development of the proinflammatory Th17 subset. © 2010 The Authors. Clinical and Experimental Immunology © 2010 British Society for Immunology.

  7. Decoding the anti-Trypanosoma cruzi action of HIV peptidase inhibitors using epimastigotes as a model.

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    Leandro S Sangenito

    Full Text Available BACKGROUND: Aspartic peptidase inhibitors have shown antimicrobial action against distinct microorganisms. Due to an increase in the occurrence of Chagas' disease/AIDS co-infection, we decided to explore the effects of HIV aspartic peptidase inhibitors (HIV-PIs on Trypanosoma cruzi, the etiologic agent of Chagas' disease. METHODOLOGY AND PRINCIPAL FINDINGS: HIV-PIs presented an anti-proliferative action on epimastigotes of T. cruzi clone Dm28c, with IC50 values ranging from 0.6 to 14 µM. The most effective inhibitors, ritonavir, lopinavir and nelfinavir, also had an anti-proliferative effect against different phylogenetic T. cruzi strains. The HIV-PIs induced some morphological alterations in clone Dm28c epimastigotes, as reduced cell size and swollen of the cellular body. Transmission electron microscopy revealed that the flagellar membrane, mitochondrion and reservosomes are the main targets of HIV-PIs in T. cruzi epimastigotes. Curiously, an increase in the epimastigote-into-trypomastigote differentiation process of clone Dm28c was observed, with many of these parasites presenting morphological alterations including the detachment of flagellum from the cell body. The pre-treatment with the most effective HIV-PIs drastically reduced the interaction process between epimastigotes and the invertebrate vector Rhodnius prolixus. It was also noted that HIV-PIs induced an increase in the expression of gp63-like and calpain-related molecules, and decreased the cruzipain expression in epimastigotes as judged by flow cytometry and immunoblotting assays. The hydrolysis of a cathepsin D fluorogenic substrate was inhibited by all HIV-PIs in a dose-dependent manner, showing that the aspartic peptidase could be a possible target to these drugs. Additionally, we verified that ritonavir, lopinavir and nelfinavir reduced drastically the viability of clone Dm28c trypomastigotes, causing many morphological damages. CONCLUSIONS AND SIGNIFICANCE: The results

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

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    Leidi Herrera

    2001-07-01

    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.

  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. Catheter-related bloodstream infection.

    Science.gov (United States)

    Goede, Matthew R; Coopersmith, Craig M

    2009-04-01

    Catheter-related bloodstream infections (CR-BSIs) are a common, frequently preventable complication of central venous catheterization. CR-BSIs can be prevented by strict attention to insertion and maintenance of central venous catheters and removing unneeded catheters as soon as possible. Antiseptic- or antibiotic-impregnated catheters are also an effective tool to prevent infections. The diagnosis of CR-BSI is made largely based on culture results. CR-BSIs should always be treated with antibiotics, and except in rare circumstances the infected catheter needs to be removed.

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

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    Zanforlin, Tamiris; Bayer-Santos, Ethel; Cortez, Cristian; Almeida, Igor C; Yoshida, Nobuko; da Silveira, José Franco

    2013-01-01

    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. 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%. This study provides novel information about the genomic organization, expression and cellular localization of SAP proteins and proposes a triggering role for extracellular SAP

  12. Distinct Trypanosoma cruzi isolates induce activation and apoptosis of human neutrophils.

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    Luísa M D Magalhães

    Full Text Available Neutrophils are critical players in the first line of defense against pathogens and in the activation of subsequent cellular responses. We aimed to determine the effects of the interaction of Trypanosoma cruzi with human neutrophils, using isolates of the two major discrete type units (DTUs associated with Chagas' disease in Latin America (clone Col1.7G2 and Y strain, DTU I and II, respectively. Thus, we used CFSE-stained trypomastigotes to measure neutrophil-T. cruzi interaction, neutrophil activation, cytokine expression and death, after infection with Col1.7G2 and Y strain. Our results show that the frequency of CFSE+ neutrophils, indicative of interaction, and CFSE intensity on a cell-per-cell basis were similar when comparing Col1.7G2 and Y strains. Interaction with T. cruzi increased neutrophil activation, as measured by CD282, CD284, TNF and IL-12 expression, although at different levels between the two strains. No change in IL-10 expression was observed after interaction of neutrophils with either strain. We observed that exposure to Y and Col1.7G2 caused marked neutrophil death. This was specific to neutrophils, since interaction of either strain with monocytes did not cause death. Our further analysis showed that neutrophil death was a result of apoptosis, which was associated with an upregulation of TNF-receptor, TNF and FasLigand, but not of Fas. Induction of TNF-associated neutrophil apoptosis by the different T. cruzi isolates may act as an effective common mechanism to decrease the host's immune response and favor parasite survival.

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

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    Vitor Sueth-Santiago

    Full Text Available 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.

  14. 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.

  15. 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

  16. Chronic Chagas disease: PCR-xenodiagnosis without previous microscopic observation is a useful tool to detect viable Trypanosoma cruzi

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    Miguel Saavedra

    2013-01-01

    Full Text Available We evaluate the elimination of the microscopic stage of conventional xenodiagnosis (XD to optimize the parasitological diagnosis of Trypanosoma cruzi in chronic Chagas disease. To this purpose we applied under informed consent two XD cages to 150 Chilean chronic chagasic patients. The fecal samples (FS of the triatomines at 30, 60 and 90 days post feeding were divided into two parts: in one a microscopic search for mobile trypomastigote and/or epimastigote forms was performed. In the other part, DNA extraction-purification for PCR directed to the conserved region of kDNA minicircles of trypanosomes (PCR-XD, without previous microscopic observation was done. An XD was considered positive when at least one mobile T. cruzi parasite in any one of three periods of incubation was observed, whereas PCR-XD was considered positive when the 330 bp band specific for T. cruzi was detected. 25 of 26 cases with positive conventional XD were PCR-XD positive (concordance 96.2%, whereas 85 of 124 cases with negative conventional XD were positive by PCR-XD (68.5%. Human chromosome 12 detected by Real-time PCR used as exogenous internal control of PCR-XD reaction allowed to discounting of PCR inhibition and false negative in 40 cases with negative PCR-XD. Conclusion: PCR-XD performed without previous microscopic observation is a useful tool for detection of viable parasites with higher efficiency then conventional XD.

  17. Chronic Chagas disease: PCR-xenodiagnosis without previous microscopic observation is a useful tool to detect viable Trypanosoma cruzi.

    Science.gov (United States)

    Saavedra, Miguel; Zulantay, Inés; Apt, Werner; Martínez, Gabriela; Rojas, Antonio; Rodríguez, Jorge

    2013-01-01

    We evaluate the elimination of the microscopic stage of conventional xenodiagnosis (XD) to optimize the parasitological diagnosis of Trypanosoma cruzi in chronic Chagas disease. To this purpose we applied under informed consent two XD cages to 150 Chilean chronic chagasic patients. The fecal samples (FS) of the triatomines at 30, 60 and 90 days post feeding were divided into two parts: in one a microscopic search for mobile trypomastigote and/or epimastigote forms was performed. In the other part, DNA extraction-purification for PCR directed to the conserved region of kDNA minicircles of trypanosomes (PCR-XD), without previous microscopic observation was done. An XD was considered positive when at least one mobile T. cruzi parasite in any one of three periods of incubation was observed, whereas PCR-XD was considered positive when the 330 bp band specific for T. cruzi was detected. 25 of 26 cases with positive conventional XD were PCR-XD positive (concordance 96.2%), whereas 85 of 124 cases with negative conventional XD were positive by PCR-XD (68.5%). Human chromosome 12 detected by Real-time PCR used as exogenous internal control of PCR-XD reaction allowed to discounting of PCR inhibition and false negative in 40 cases with negative PCR-XD. PCR-XD performed without previous microscopic observation is a useful tool for detection of viable parasites with higher efficiency then conventional XD.

  18. Candida Infection of the Bloodstream - Candidemia

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    Candida Infection of the Bloodstream– Candidemia Fungal Disease Series #4 Candida is the single most important cause of fungal infections worldwide. In the U.S., Candida is the 4th most common cause of bloodstream ...

  19. Trypanosoma cruzi Necrotizing Meningoencephalitis in a Venezuelan HIV+-AIDS Patient: Pathological Diagnosis Confirmed by PCR Using Formalin-Fixed- and Paraffin-Embedded-Tissues

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    Marcello Salvatore Rossi Spadafora

    2014-01-01

    Full Text Available Coinfections with human immunodeficiency virus (HIV and infectious agents have been recognized since the early 90s. In the central nervous system (CNS of HIV+ patients, parasitic protozoans like Toxoplasma gondii have been described as responsible for the space occupying lesions (SOL developed. However, the involvement of Trypanosoma cruzi is also described but appears to be less frequent in acquired immunodeficiency syndrome (AIDS and transplant recipients, associated with necrotizing myocarditis and neurological symptoms related to the occurrence of necrotizing pseudotumoral encephalitis (NPE and meningoencephalitis (NME. The present work aims to present a Venezuelan case of NME associated with the coinfection of HIV and a T. cruzi-like trypanosomatid as well as its evolution and diagnosis by histopathological techniques, electron microscopy, and PCR methods using formalin-fixed- (FF- and paraffin-embedded- (PE- tissues. Postmortem cytological studies of leptomeninges imprints reveal the presence of trypomastigotes of Trypanosoma sp. Histopathological and electron microscopy studies allowed us to identify an amastigote stage and to reject the involvement of other opportunistic microorganisms as the etiological agent of the SOL. The definitive confirmation of T. cruzi as the etiological agent was achieved by PCR suggesting that the NME by T. cruzi was due to a reactivation of Chagas’ disease.

  20. Trypanosoma cruzi Necrotizing Meningoencephalitis in a Venezuelan HIV+-AIDS Patient: Pathological Diagnosis Confirmed by PCR Using Formalin-Fixed- and Paraffin-Embedded-Tissues

    Science.gov (United States)

    Rossi Spadafora, Marcello Salvatore; Céspedes, Ghislaine; Romero, Sandra; Fuentes, Isabel; Boada-Sucre, Alpidio A.; Cañavate, Carmen; Flores-Chávez, María

    2014-01-01

    Coinfections with human immunodeficiency virus (HIV) and infectious agents have been recognized since the early 90s. In the central nervous system (CNS) of HIV+ patients, parasitic protozoans like Toxoplasma gondii have been described as responsible for the space occupying lesions (SOL) developed. However, the involvement of Trypanosoma cruzi is also described but appears to be less frequent in acquired immunodeficiency syndrome (AIDS) and transplant recipients, associated with necrotizing myocarditis and neurological symptoms related to the occurrence of necrotizing pseudotumoral encephalitis (NPE) and meningoencephalitis (NME). The present work aims to present a Venezuelan case of NME associated with the coinfection of HIV and a T. cruzi-like trypanosomatid as well as its evolution and diagnosis by histopathological techniques, electron microscopy, and PCR methods using formalin-fixed- (FF-) and paraffin-embedded- (PE-) tissues. Postmortem cytological studies of leptomeninges imprints reveal the presence of trypomastigotes of Trypanosoma sp. Histopathological and electron microscopy studies allowed us to identify an amastigote stage and to reject the involvement of other opportunistic microorganisms as the etiological agent of the SOL. The definitive confirmation of T. cruzi as the etiological agent was achieved by PCR suggesting that the NME by T. cruzi was due to a reactivation of Chagas' disease. PMID:25763312

  1. 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.

  2. TcI Isolates of Trypanosoma cruzi Exploit the Antioxidant Network for Enhanced Intracellular Survival in Macrophages and Virulence in Mice.

    Science.gov (United States)

    Zago, María Paola; Hosakote, Yashoda M; Koo, Sue-Jie; Dhiman, Monisha; Piñeyro, María Dolores; Parodi-Talice, Adriana; Basombrio, Miguel A; Robello, Carlos; Garg, Nisha J

    2016-06-01

    Trypanosoma cruzi species is categorized into six discrete typing units (TcI to TcVI) of which TcI is most abundantly noted in the sylvatic transmission cycle and considered the major cause of human disease. In our study, the TcI strains Colombiana (COL), SylvioX10/4 (SYL), and a cultured clone (TCC) exhibited different biological behavior in a murine model, ranging from high parasitemia and symptomatic cardiomyopathy (SYL), mild parasitemia and high tissue tropism (COL), to no pathogenicity (TCC). Proteomic profiling of the insect (epimastigote) and infective (trypomastigote) forms by two-dimensional gel electrophoresis/matrix-assisted laser desorption ionization-time of flight mass spectrometry, followed by functional annotation of the differential proteome data sets (≥2-fold change, P < 0.05), showed that several proteins involved in (i) cytoskeletal assembly and remodeling, essential for flagellar wave frequency and amplitude and forward motility of the parasite, and (ii) the parasite-specific antioxidant network were enhanced in COL and SYL (versus TCC) trypomastigotes. Western blotting confirmed the enhanced protein levels of cytosolic and mitochondrial tryparedoxin peroxidases and their substrate (tryparedoxin) and iron superoxide dismutase in COL and SYL (versus TCC) trypomastigotes. Further, COL and SYL (but not TCC) were resistant to exogenous treatment with stable oxidants (H2O2 and peroxynitrite [ONOO(-)]) and dampened the intracellular superoxide and nitric oxide response in macrophages, and thus these isolates escaped from macrophages. Our findings suggest that protein expression conducive to increase in motility and control of macrophage-derived free radicals provides survival and persistence benefits to TcI isolates of T. cruzi. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  3. Highly diluted medication reduces tissue parasitism and inflammation in mice infected by Trypanosoma cruzi.

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    Lopes, Carina Ribeiro; Falkowski, Gislaine Janaina Sanchez; Brustolin, Camila Fernanda; Massini, Paula Fernanda; Ferreira, Érika Cristina; Moreira, Neide Martins; Aleixo, Denise Lessa; Kaneshima, Edilson Nobuyoshi; de Araújo, Silvana Marques

    2016-05-01

    To evaluate the effects of Kalium causticum, Conium maculatum, and Lycopodium clavatum 13cH in mice infected by Trypanosoma cruzi. In a blind, controlled, randomized study, 102 male Swiss mice, 8 weeks old, were inoculated with 1400 trypomastigotes of the Y strain of T. cruzi and distributed into the following groups: CI (treated with 7% hydroalcoholic solution), Ca (treated with Kalium causticum 13cH), Co (treated with Conium maculatum 13cH), and Ly (treated with Lycopodium clavatum 13cH). The treatments were performed 48 h before and 48, 96, and 144 h after infection. The medication was repertorized and prepared in 13cH, according to Brazilian Homeopathic Pharmacopoeia. The following parameters were evaluated: infectivity, prepatent period, parasitemia peak, total parasitemia, tissue tropism, inflammatory infiltrate, and survival. Statistical analysis was conduced considering 5% of significance. The prepatent period was greater in the Ly group than in the CI group (p = 0.02). The number of trypomastigotes on the 8th day after infection was lower in the Ca group than in the CI group (p < 0.05). Total parasitemia was significantly lower in the Ca, Co, and Ly groups than in the CI group. On the 12th day after infection, the Ca, Co, and Ly groups had fewer nests and amastigotes/nest in the heart than the CI group (p < 0.05). Decreases in the number of nests and amastigotes in the intestine were observed in the Ly group compared with the CI group (p < 0.05). In the liver (day 12), Ly significantly prevented the formation of inflammatory foci compared with the other groups. In skeletal muscle, Co and Ly decreased the formation of inflammatory foci compared with CI (p < 0.05). Ly afforded greater animal survival compared with CI, Ca, and Co (p < 0.05). The animals in the Co group died prematurely compared with the CI group (p = 0.03). Ly with 13cH potency had significantly more benefits in the treatment of mice infected with T. cruzi, reducing the number

  4. Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon.

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    Valdirene Dos Santos Lima

    Full Text Available Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil.

  5. Probing the metabolic network in bloodstream-form Trypanosoma brucei using untargeted metabolomics with stable isotope labelled glucose.

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    Darren J Creek

    2015-03-01

    Full Text Available Metabolomics coupled with heavy-atom isotope-labelled glucose has been used to probe the metabolic pathways active in cultured bloodstream form trypomastigotes of Trypanosoma brucei, a parasite responsible for human African trypanosomiasis. Glucose enters many branches of metabolism beyond glycolysis, which has been widely held to be the sole route of glucose metabolism. Whilst pyruvate is the major end-product of glucose catabolism, its transamination product, alanine, is also produced in significant quantities. The oxidative branch of the pentose phosphate pathway is operative, although the non-oxidative branch is not. Ribose 5-phosphate generated through this pathway distributes widely into nucleotide synthesis and other branches of metabolism. Acetate, derived from glucose, is found associated with a range of acetylated amino acids and, to a lesser extent, fatty acids; while labelled glycerol is found in many glycerophospholipids. Glucose also enters inositol and several sugar nucleotides that serve as precursors to macromolecule biosynthesis. Although a Krebs cycle is not operative, malate, fumarate and succinate, primarily labelled in three carbons, were present, indicating an origin from phosphoenolpyruvate via oxaloacetate. Interestingly, the enzyme responsible for conversion of phosphoenolpyruvate to oxaloacetate, phosphoenolpyruvate carboxykinase, was shown to be essential to the bloodstream form trypanosomes, as demonstrated by the lethal phenotype induced by RNAi-mediated downregulation of its expression. In addition, glucose derivatives enter pyrimidine biosynthesis via oxaloacetate as a precursor to aspartate and orotate.

  6. Monoclonal antibodies (MAb) made against insect-derived metacyclic trypomastigotes (IMT) of Trypanosoma cruzi (TC) cross-react with other parasite forms

    International Nuclear Information System (INIS)

    Kirchhoff, L.V.; Gilliam, F.C.

    1986-01-01

    Considerable information has been generated in recent years about stage-specific surface membrane antigens of a number of protozoa, and this phenomenon has been observed among several stages of TC as well. However, little is known about the surface antigens of IMT, the true infective stage of TC, because of the difficulty of obtaining sufficient numbers of these organisms for analysis. The Tulahuen strain of TC was maintained in the reduviid vector Dipetalogaster maximus by repeated feeding on mice with high parasitemias. IMT collected with insect urine were irradiated (150 krad) and used to immunize a BALB/c mouse for hybridoma production. Supernatants were screened by immunofluorescence assay for the presence of IgG MAb that react with methanol-fixed IMT, epimastogotes (EPI) and culture-derived metacyclic trypomastigoes (CMT). Of 41 MAb obtained, 40 reacted with IMT, 37 with EPI and 38 with CMT. Four MAb immunoprecipitated radioiodinated proteins or protein conjugates of M/sub r/ 80, 72, 45 and 45 from lysates of 125 I surface-labeled EPI. These results indicate that, at least at the epitopic level, there is considerable overlap among IMT, EPI and CMT surface antigens. This finding suggests that analysis of surface proteins of the latter 2 parasite forms may lead to identification of molecules useful for vaccine development

  7. Molecular Characterization of a Novel Family of Trypanosoma cruzi Surface Membrane Proteins (TcSMP) Involved in Mammalian Host Cell Invasion.

    Science.gov (United States)

    Martins, Nadini Oliveira; Souza, Renata Torres de; Cordero, Esteban Mauricio; Maldonado, Danielle Cortez; Cortez, Cristian; Marini, Marjorie Mendes; Ferreira, Eden Ramalho; Bayer-Santos, Ethel; Almeida, Igor Correia de; Yoshida, Nobuko; Silveira, José Franco da

    2015-11-01

    The surface coat of Trypanosoma cruzi is predominantly composed of glycosylphosphatidylinositol-anchored proteins, which have been extensively characterized. However, very little is known about less abundant surface proteins and their role in host-parasite interactions. Here, we described a novel family of T. cruzi surface membrane proteins (TcSMP), which are conserved among different T. cruzi lineages and have orthologs in other Trypanosoma species. TcSMP genes are densely clustered within the genome, suggesting that they could have originated by tandem gene duplication. Several lines of evidence indicate that TcSMP is a membrane-spanning protein located at the cellular surface and is released into the extracellular milieu. TcSMP exhibited the key elements typical of surface proteins (N-terminal signal peptide or signal anchor) and a C-terminal hydrophobic sequence predicted to be a trans-membrane domain. Immunofluorescence of live parasites showed that anti-TcSMP antibodies clearly labeled the surface of all T. cruzi developmental forms. TcSMP peptides previously found in a membrane-enriched fraction were identified by proteomic analysis in membrane vesicles as well as in soluble forms in the T. cruzi secretome. TcSMP proteins were also located intracellularly likely associated with membrane-bound structures. We demonstrated that TcSMP proteins were capable of inhibiting metacyclic trypomastigote entry into host cells. TcSMP bound to mammalian cells and triggered Ca2+ signaling and lysosome exocytosis, events that are required for parasitophorous vacuole biogenesis. The effects of TcSMP were of lower magnitude compared to gp82, the major adhesion protein of metacyclic trypomastigotes, suggesting that TcSMP may play an auxiliary role in host cell invasion. We hypothesized that the productive interaction of T. cruzi with host cells that effectively results in internalization may depend on diverse adhesion molecules. In the metacyclic forms, the signaling induced by

  8. Experimental infection of two South American reservoirs with four distinct strains of Trypanosoma cruzi

    Science.gov (United States)

    Roellig, Dawn M.; McMillan, Katherine; Ellis, Angela E.; Vandeberg, John L.; Champagne, Donald E.; Yabsley, Michael J.

    2010-01-01

    SUMMARY Trypanosoma cruzi (Tc), the causative agent of Chagas disease, is a diverse species with 2 primary genotypes, TcI and TcII, with TcII further subdivided into 5 subtypes (IIa–e). This study evaluated infection dynamics of 4 genetically and geographically diverse T. cruzi strains in 2 South American reservoirs, degus (Octodon degus) and grey short-tailed opossums (Monodelphis domestica). Based on prior suggestions of a genotype-host association, we hypothesized that degus (placental) would more readily become infected with TcII strains while short-tailed opossums (marsupial) would be a more competent reservoir for a TcI strain. Individuals (n = 3) of each species were intraperitoneally inoculated with T. cruzi trypomastigotes of TcIIa [North America (NA)-raccoon (Procyon lotor) origin], TcI [NA-Virginia opossum (Didelphis virginiana)], TcIIb [South America (SA)-human], TcIIe (SA-Triatoma infestans), or both TcI and TcIIa. Parasitaemias in experimentally infected degus peaked earlier (7–14 days post-inoculation (p.i.)) compared with short-tailed opossums (21–84 days p.i.). Additionally, peak parasitaemias were higher in degus; however, the duration of detectable parasitaemias for all strains, except TcIIa, was greater in short-tailed opossums. Infections established in both host species with all genotypes, except for TcIIa, which did not establish a detectable infection in short-tailed opossums. These results indicate that both South American reservoirs support infections with these isolates from North and South America; however, infection dynamics differed with host and parasite strain. PMID:20128943

  9. In vitro and in vivo trypanocidal evaluation of nickel complexes with an azapurine derivative against Trypanosoma cruzi.

    Science.gov (United States)

    Maldonado, Carmen R; Marín, Clotilde; Olmo, Francisco; Huertas, Oscar; Quirós, Miguel; Sánchez-Moreno, Manuel; Rosales, María J; Salas, Juan M

    2010-10-14

    Seven ternary nickel(II) complexes (three previously described and four firstly described here) with an azapurine derivative (the anionic form of 4,6-dimethyl-1,2,3-triazolo[4,5-d]pyrimidin-5,7-dione) have been synthesized and spectroscopically characterized, and the crystal structures of three of them have been solved by X-ray diffraction. Studies in vitro and in vivo on the antiproliferative activity of these complexes against Trypanosoma cruzi (epimastigote, amastigote, and trypomastigote forms) have been carried out, displaying in some cases significantly higher antitrypanosomatid activity and lower toxicity than the reference drug for Chagas' disease, benznidazole (N-benzyl-2-(2-nitro-1H-imidazol-1-yl)acetamide). Ultrastructural analysis and metabolism excretion studies were also executed in order to propose a possible mechanism of action for the assayed drugs.

  10. Simultaneous identification of Trypanosoma cruzi surface and internal antigens reactive to different immunoglobulin classes (radio-immunoblotting)

    International Nuclear Information System (INIS)

    Stolf, A.M.S.; Umezawa, E.S.; Zingales, B.

    1990-01-01

    A radioactive Western blotting technique was developed by which the reactivity of Immunoglobulins (IGs) from different classes to both membrane radiolabelled and internal parasite antigens is simultaneously identified. The method includes radioiodination of parasites, polypeptide fractionation by SDS-PAGE, Western-blot transfer and autoradiography of the immunoblots developed with anti-Igs conjugates labelled with enzymes. The analysis is then performed by the comparison of common bands on the autoradiograms and the respective substrate stained nitrocellulose blots. This technique was used to analyse. T.cruzi trypomastigote surface labelled antigens reactive to IgM, IgA and IgC specific antibodies. A different pattern of reactivity with acute Chagas disease patients sera was thus obtained. (author)

  11. Synthesis and biological evaluation of some novel 1-indanone thiazolylhydrazone derivatives as anti-Trypanosoma cruzi agents.

    Science.gov (United States)

    Caputto, María E; Ciccarelli, Alejandra; Frank, Fernanda; Moglioni, Albertina G; Moltrasio, Graciela Y; Vega, Daniel; Lombardo, Elisa; Finkielsztein, Liliana M

    2012-09-01

    A series of novel 4-arylthiazolylhydrazones (TZHs) derived from 1-indanones were synthesized in good yields (66-92%) in a simple procedure using microwave irradiation and then characterized by spectroscopy studies. The compounds were evaluated for their in vitro anti-Trypanosoma cruzi activity against the epimastigote, trypomastigote and amastigote forms of the parasite. Most TZHs displayed excellent activity, and were more potent and selective than the reference drug Benznidazole, used in the current chemotherapy. Analysis of the free sterols from parasite incubated with the compounds showed that inhibition of ergosterol biosynthesis is a possible target for the action of these new TZHs. In particular, TZH 9 emerged as a promising antichagasic compound to be evaluated in animal models. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  12. Nitric oxide synthase and oxidative-nitrosative stress play a key role in placental infection by Trypanosoma cruzi.

    Science.gov (United States)

    Triquell, María Fernanda; Díaz-Luján, Cintia; Romanini, María Cristina; Ramirez, Juan Carlos; Paglini-Oliva, Patricia; Schijman, Alejandro Gabriel; Fretes, Ricardo Emilio

    2018-03-25

    The innate immune response of the placenta may participate in the congenital transmission of Chagas disease through releasing reactive oxygen and nitrogen intermediates. Placental explants were cultured with 1 × 10 6 and 1 × 10 5 trypomastigotes of Tulahuen and Lucky strains and controls without parasites, and with the addition of nitric oxide synthase inhibitor Nω-Nitro-l-arginine methyl ester (l-NAME) and N-acetyl cysteine (NAC) as the reactive oxygen species (ROS) scavenger. Detachment of the syncytiotrophoblast (STB) was examined by histological analysis, and the nitric oxide synthase, endothelial (eNOS), and nitrotyrosine expressions were analyzed by immunohistochemistry, as well as the human chorionic gonadotrophin (hCG) levels in the culture supernatant through ELISA assays. Parasite load with qPCR using Taqman primers was quantified. The higher number of T. cruzi (10 6 ) increased placental infection, eNOS expression, nitrosative stress, and STB detachment, with the placental barrier being injured by oxidative stress. The higher number of parasites caused deleterious consequences to the placental barrier, and the inhibitors (l-NAME and NAC) prevented the damage caused by trypomastigotes in placental villi but not that of the infection. Moreover, trophoblast eNOS played a key role in placental infection with the highest inoculum of Lucky, demonstrating the importance of the enzyme and nitrosative-oxidative stress in Chagas congenital transmission. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

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    Frederico G.C. Abath

    1986-09-01

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

  14. 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

  15. Morphological evidence by scanning electron microscopy of excretion of metacyclic forms of Trypanosoma cruzi in vector's urine

    Directory of Open Access Journals (Sweden)

    Rodrigo Zeledon

    1988-09-01

    Full Text Available Comparision by scanning electron microscopy (SEM of Trypanosoma cruzi flagellates attached to the cuticle of the rectal gland of infected Dipetalogaster maxima nymphs, showed marked differences before amd after feeding. Before feeding numerous metacyclic trypomastigotes were observed among the abundant epimastigotes that formed the carpet of flagellates. On the other hand, in insects that were allowed to urinate for 24 hours after a meal, the metacyclics were scarce,indicating that they had been detached by the urine flow. An asymetric type of cell division, probably originating both an epi-and a trypomastigote, was occasionally observed. The occurrence of swellings at different levels of the flagella of epimastigotes suggests that secondary sites of attachment may be common.Observando-se, em microscopia eletrônica de varedura, formas flageladas do Trypanosoma cruzi presas a cutícula da glândula retal de ninfas infectadas de Dipetalogaster maxima verificaram-se nítidas diferenças antes e depois da alimentação. Antes, viam-se numerosos tripomastigotas metacíclicos entre os abundantes epimastigotas que formavam o tapete de flagelados, ao passo que nos insetos que urinavam dentro das 24 horas após o repasto os metacíclicos eram raros, indicando que haviam sido desprendidos pelo fluxo urinário. Foi notado, as vezes, um tipo assimétrico de divisão celular, originando um epi e um tripomastigota. Nos flagelados dos epimastigotas a presença de dilatações a diferentes níveis sugere que lugares secundários de aderência podem ser comuns.

  16. Aspects of resistance to experimental infection with Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Dias, Viviane Liotti

    2010-01-01

    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 1 , 10 2 , 10 3 and 10 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 chromosomes are an

  17. 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

  18. Bloodstream Infections with Mycobacterium tuberculosis among HIV patients

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    This podcast looks at bloodstream infections with Mycobacterium tuberculosis and other pathogens among outpatients infected with HIV in Southeast Asia. CDC health scientist Kimberly McCarthy discusses the study and why bloodstream infections occur in HIV-infected populations.

  19. Biological aspects of the DM28C clone of Trypanosoma cruzi after metacylogenesis in chemically defined media Aspectos biológicos do clone Dm 28c de Trypanosoma cruzi após metaciclogênese em meio quimicamente definido

    Directory of Open Access Journals (Sweden)

    Victor T. Contreras

    1988-03-01

    Full Text Available The biological characterization of the Trypanosoma cruzi clone Dm 28c in terms of its growth in LIT medium, cell-cycle, infectivity to mice and interaction with professional and non-professional phagocytic cells shows that it behaves as a bona fide T. cruzi representant. The biological properties of this myotropic clone do not change according to the origin of the trypomastigote forms (i. e., from triatomines, infected mice, cell-culture or from the chemically defined TAUP and TAU3AAG media. In addition Dm 28c metacyclic trypomastigotes from TAU3AAG medium display a high infectivity level to fibroblasts and muscle cells. Experiments on binding of cationized ferritin to trypomastigotes surface show the existence of cap-like structures of ferritin in regions near the kinetoplast. However the nature and role of these anionic sites remain to be determined. The results indicate that metacyclic trypomastigotes from Dm 28c clone obtained under chemically defined conditions reproduce the biological behaviour of T. cruzi, rendering this system very suitable for the study of cell-parasite interactions and for the isolation of trypanosome relevant macromolecules.A caracterização biológica do clone Dm 28c de Trypanosoma cruzi em termos do seu crescimento em meio LIT, ciclo celular, infectividade para camundongos e interação com células fagocíticas profissionais e não-profissionais, mostra que o mesmo comporta-se como um fiel representante da espécie T. cruzi. As propriedades biológicas deste clone miotrópico não mudam de acordo com a proveniência das formas tripomastigotas (i. e., de triatomíneos, de camundongos infectados, de cultura celular ou dos meios quimicamente definidos TAUP e TAU3AAG. Ainda mais, formas tripomastigotas metacíclicas do clone Dm 28c derivado do meio TAU3AAG apresentam um alto grau de infectividade para fibroblastos e células de músculo. Experimentos de ligação de ferritina cationizada à superfície de

  20. 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.

  1. Prevalence of Trypanosoma cruzi infection among Bolivian immigrants in the city of São Paulo, Brazil

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    Expedito JA Luna

    Full Text Available With the urbanisation of the population in developing countries and the process of globalisation, Chagas has become an emerging disease in the urban areas of endemic and non-endemic countries. In 2006, it was estimated that the prevalence of Chagas disease among the general Bolivian population was 6.8%. The aim of the present study was to determine the prevalence of Trypanosoma cruzi infection among Bolivian immigrants living in São Paulo, Brazil. This study had a sample of 633 volunteers who were randomly selected from the clientele of primary care units located in the central districts of São Paulo, Brazil. Infection was detected by two different ELISA assays with epimastigote antigens, followed by an immunoblot with trypomastigote antigens as a confirmatory test. The prevalence of the infection was 4.4%. Risk factors independently associated with the infection were: a history of rural jobs in Bolivia, knowledge of the vector involved in transmission, and having relatives with Chagas disease. Brazil has successfully eliminated household vector transmission of T. cruzi, as well as its transmission by blood transfusion. The arrival of infected immigrants represents an additional challenge to primary care clinics to manage chronic Chagas disease, its vertical transmission, and the blood derivatives and organ transplant programs.

  2. Trypanocidal Effect of Isotretinoin through the Inhibition of Polyamine and Amino Acid Transporters in Trypanosoma cruzi.

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    Chantal Reigada

    2017-03-01

    Full Text Available Polyamines are essential compounds to all living organisms and in the specific case of Trypanosoma cruzi, the causative agent of Chagas disease, they are exclusively obtained through transport processes since this parasite is auxotrophic for polyamines. Previous works reported that retinol acetate inhibits Leishmania growth and decreases its intracellular polyamine concentration. The present work describes a combined strategy of drug repositioning by virtual screening followed by in vitro assays to find drugs able to inhibit TcPAT12, the only polyamine transporter described in T. cruzi. After a screening of 3000 FDA-approved drugs, 7 retinoids with medical use were retrieved and used for molecular docking assays with TcPAT12. From the docked molecules, isotretinoin, a well-known drug used for acne treatment, showed the best interaction score with TcPAT12 and was selected for further in vitro studies. Isotretinoin inhibited the polyamine transport, as well as other amino acid transporters from the same protein family (TcAAAP, with calculated IC50 values in the range of 4.6-10.3 μM. It also showed a strong inhibition of trypomastigote burst from infected cells, with calculated IC50 of 130 nM (SI = 920 being significantly less effective on the epimastigote stage (IC50 = 30.6 μM. The effect of isotretinoin on the parasites plasma membrane permeability and on mammalian cell viability was tested, and no change was observed. Autophagosomes and apoptotic bodies were detected as part of the mechanisms of isotretinoin-induced death indicating that the inhibition of transporters by isotretinoin causes nutrient starvation that triggers autophagic and apoptotic processes. In conclusion, isotretinoin is a promising trypanocidal drug since it is a multi-target inhibitor of essential metabolites transporters, in addition to being an FDA-approved drug largely used in humans, which could reduce significantly the requirements for its possible application in the

  3. New alkenyl derivative from Piper malacophyllum and analogues: Antiparasitic activity against Trypanosoma cruzi and Leishmania infantum.

    Science.gov (United States)

    Varela, Marina T; Lima, Marta L; Galuppo, Mariana K; Tempone, Andre G; de Oliveira, Alberto; Lago, João Henrique G; Fernandes, João Paulo S

    2017-11-01

    Alkylphenols isolated from Piper malacophyllum (Piperaceae), gibbilimbols A and B, showed interesting activity against the parasites Trypanosoma cruzi and Leishmania infantum. In continuation to our previous work, a new natural product from the essential oil of the leaves of P. malacophyllum was isolated, the 5-[(3E)-oct-3-en-1-il]-1,3-benzodioxole, and also a new set of five compounds was prepared. The antiparasitic activity of the natural product was evaluated in vitro against these parasites, indicating potential against the promastigote/trypomastigote/amastigote forms (IC 50 32-83 μm) of the parasites and low toxicity (CC 50  > 200 μm) to mammalian cells. The results obtained to the synthetic compounds indicated that the new derivatives maintained the promising antiparasitic activity, but the cytotoxicity was considerably lowered. The amine derivative LINS03011 displayed the most potent IC 50 values (13.3 and 16.7 μm) against amastigotes of T. cruzi and L. infantum, respectively, indicating comparable activity to the phenolic prototype LINS03003, with threefold decreased (CC 50 73.5 μm) cytotoxicity, leading the selectivity index (SI) towards the parasites up to 24.5. In counterpart, LINS03011 has not shown membrane disruptor activity in SYTOX Green model. In summary, this new set showed the hydroxyl is not essential for the antiparasitic activity, and its substitution could decrease the toxicity to mammalian cells. © 2017 John Wiley & Sons A/S.

  4. Trypanosoma teixeirae: A new species belonging to the T. cruzi clade causing trypanosomosis in an Australian little red flying fox (Pteropus scapulatus).

    Science.gov (United States)

    Barbosa, Amanda D; Mackie, John T; Stenner, Robyn; Gillett, Amber; Irwin, Peter; Ryan, Una

    2016-06-15

    Little is known about the genetic diversity and pathogenicity of trypanosomes in Australian bats. Recently a novel trypanosome species was identified in an adult female little red flying fox (Pteropus scapulatus) with clinical and pathological evidence of trypanosomosis. The present study used morphology and molecular methods to demonstrate that this trypanosome is a distinct species and we propose the name Trypanosoma teixeirae sp. n. Morphological comparison showed that its circulating trypomastigotes were significantly different from those of Trypanosoma pteropi and Trypanosoma hipposideri, two species previously described from Australian bats. Genetic information was not available for T. pteropi and T. hipposideri but phylogenetic analyses at the 18S ribosomal RNA (rRNA) and glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH) loci indicated that T. teixeirae sp. n. was genetically distinct and clustered with other bat-derived trypanosome species within the Trypanosoma cruzi clade. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Decay-accelerating factor 1 deficiency exacerbates Trypanosoma cruzi-induced murine chronic myositis.

    Science.gov (United States)

    Solana, María E; Ferrer, María F; Novoa, María Mercedes; Song, Wen-Chao; Gómez, Ricardo M

    2012-10-01

    Murine infection with Trypanosoma cruzi (Tc) has been used to study the role of T-cells in the pathogenesis of human inflammatory idiopathic myositis. Absence of decay-accelerating factor 1 (Daf1) has been shown to enhance murine T-cell responses and autoimmunity. To determine whether Daf1 deficiency can exacerbate Tc-induced myositis, C57BL/6 DAF(+/+) and DAF(-/-) mice were inoculated with 5 × 10(4) trypomastigotes, and their morbidity, parasitemia, parasite burden, histopathology, and T-cell expansion were studied in the acute and chronic stages. DAF(-/-) mice had lower parasitemia and parasite burden but higher morbidity, muscle histopathology, and increased number of CD44(+) (activated/memory phenotype) splenic CD4(+) and CD8(+) T-cells. An enhanced CD8(+) T-cell immune-specific response may explain the lower parasitemia and parasite burden levels and the increase in histopathological lesions. We propose that Tc-inoculated DAF(-/-) mice are a useful model to study T-cell mediated immunity in skeletal muscle tissues. Copyright © 2012 Wiley Periodicals, Inc.

  6. Trypanosoma cruzi 80 kDa prolyl oligopeptidase (Tc80 as a novel immunogen for Chagas disease vaccine.

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    Augusto E Bivona

    2018-03-01

    Full Text Available Chagas disease, also known as American Trypanosomiasis, is a chronic parasitic disease caused by the flagellated protozoan Trypanosoma cruzi that affects about 8 million people around the world where more than 25 million are at risk of contracting the infection. Despite of being endemic on 21 Latin-American countries, Chagas disease has become a global concern due to migratory movements. Unfortunately, available drugs for the treatment have several limitations and they are generally administered during the chronic phase of the infection, when its efficacy is considered controversial. Thus, prophylactic and/or therapeutic vaccines are emerging as interesting control alternatives. In this work, we proposed Trypanosoma cruzi 80 kDa prolyl oligopeptidase (Tc80 as a new antigen for vaccine development against Chagas disease.In a murine model, we analyzed the immune response triggered by different immunization protocols based on Tc80 and evaluated their ability to confer protection against a challenge with the parasite. Immunized mice developed Tc80-specific antibodies which were able to carry out different functions such as: enzymatic inhibition, neutralization of parasite infection and complement-mediated lysis of trypomastigotes. Furthermore, vaccinated mice elicited strong cell-mediated immunity. Spleen cells from immunized mice proliferated and secreted Th1 cytokines (IL-2, IFN-γ and TNF-α upon re-stimulation with rTc80. Moreover, we found Tc80-specific polyfunctional CD4 T cells, and cytotoxic T lymphocyte activity against one Tc80 MHC-I peptide. Immunization protocols conferred protection against a T. cruzi lethal challenge. Immunized groups showed a decreased parasitemia and higher survival rate compared with non-immunized control mice. Moreover, during the chronic phase of the infection, immunized mice presented: lower levels of myopathy-linked enzymes, parasite burden, electrocardiographic disorders and inflammatory cells.Considering that

  7. Predominance of Th1 response, increase of megakaryocytes and Kupffer cells are related to survival in Trypanosoma cruzi infected mice treated with Lycopodium clavatum.

    Science.gov (United States)

    Falkowski-Temporini, Gislaine Janaina; Lopes, Carina Ribeiro; Massini, Paula Fernanda; Brustolin, Camila Fernanda; Sandri, Patricia Flora; Ferreira, Érika Cristina; Aleixo, Denise Lessa; Pala, Nelson Roberto; de Araújo, Silvana Marques

    2016-12-01

    We investigated the number of megakaryocytes, Kupffer cells and ratios of Th1/Th2 and Th1/Th17 cytokines in survival of mice infected with Y strain of Trypanosoma cruzi and treated with Lycopodium clavatum. In a blind, randomized and controlled assay, Swiss male mice, 8weeks-old, infected with 1400 trypomastigotes (Y strain) were divided into groups and treated with: GLy - Lycopodium clavatum dynamization13c and GCI - alcohol solution 7° GL (vehicle medicine). The treatment was offered two days before infection and on the 2nd, 4th and 6th days after infection, overnight (1mL/100mL) and ad libitum. Parameters assessed were: survival rate, number of megakaryocytes and Kupffer cells, cytokines dosage (TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10, IL-17), Th1/Th2 and Th1/Th17 ratios. The increase in megakaryocytes, Kupffer cells, predominance of Th1 response, with increased TNF-α, IL-10, TNF-α/IL-4, TNF-α/IL-17 and decreased IL-6 IL-6/IL-4, are related to increased survival in mice infected with T. cruzi and treated with Lycopodium clavatum 13c. This result demonstrates the possibility of an alternative approach for the treatment of Chagas disease with dynamized drugs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Peridomiciliary colonies of Triatoma vitticeps (Stal, 1859 (Hemiptera, Reduviidae, Triatominae infected with Trypanosoma cruzi in rural areas of the state of Espírito Santo, Brazil

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    Claudiney Biral dos Santos

    2005-08-01

    Full Text Available In Brazil, the colonization of human dwellings by triatomines occurs in areas with native vegetation of the caatinga or cerrado types. In areas of Atlantic forest such as in the Brazilian state of Espírito Santo, there are no species adapted to live in human habitations. The few autochthonous cases of Chagas disease encountered in Espírito Santo have been attributed to adult specimens of Triatoma vitticeps that invade houses from forest remnants. In recent years, the entomology unit of the Espírito Santo State Health Secretariat has recorded nymphs infected with flagellates similar to Trypanosoma cruzi in rural localities. Entomological surveys were carried out in the residences and outbuildings in which the insects were found, and serological examinations for Chagas disease performed on the inhabitants. Four colonies were found, all associated with nests of opossums (Didelphis aurita, 111 specimens of T. vitticeps, and 159 eggs being collected. All the triatomines presented flagellates in their frass. Mice inoculated with the faeces presented trypomastigotes in the circulating blood and groups of amastigotes in the cardiac muscle fibres. Serological tests performed on the inhabitants were negative for T. cruzi. Even with the intense devastation of the forest in Espírito Santo, there are no indications of change in the sylvatic habits of T. vitticeps. Colonies of this insect associated with opossum nests would indicate an expansion of the sylvatic environment into the peridomicile.

  9. Actions of a proline analogue, L-thiazolidine-4-carboxylic acid (T4C, on Trypanosoma cruzi.

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    Anahí Magdaleno

    Full Text Available It is well established that L-proline has several roles in the biology of trypanosomatids. In Trypanosoma cruzi, the etiological agent of Chagas' disease, this amino acid is involved in energy metabolism, differentiation processes and resistance to osmotic stress. In this study, we analyzed the effects of interfering with L-proline metabolism on the viability and on other aspects of the T. cruzi life cycle using the proline analogue L- thiazolidine-4-carboxylic acid (T4C. The growth of epimastigotes was evaluated using different concentrations of T4C in standard culture conditions and at high temperature or acidic pH. We also evaluated possible interactions of this analogue with stress conditions such as those produced by nutrient starvation and oxidative stress. T4C showed a dose-response effect on epimastigote growth (IC(50 = 0.89+/-0.02 mM at 28 degrees C, and the inhibitory effect of this analogue was synergistic (p<0.05 with temperature (0.54+/-0.01 mM at 37 degrees C. T4C significantly diminished parasite survival (p<0.05 in combination with nutrient starvation and oxidative stress conditions. Pre-incubation of the parasites with L-proline resulted in a protective effect against oxidative stress, but this was not seen in the presence of the drug. Finally, the trypomastigote bursting from infected mammalian cells was evaluated and found to be inhibited by up to 56% when cells were treated with non-toxic concentrations of T4C (between 1 and 10 mM. All these data together suggest that T4C could be an interesting therapeutic drug if combined with others that affect, for example, oxidative stress. The data also support the participation of proline metabolism in the resistance to oxidative stress.

  10. A Carbohydrate Moiety of Secreted Stage-Specific Glycoprotein 4 Participates in Host Cell Invasion by Trypanosoma cruzi Extracellular Amastigotes

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    Pilar T. V. Florentino

    2018-04-01

    Full Text Available Trypanosoma cruzi is the etiologic agent of Chagas’ disease. It is known that amastigotes derived from trypomastigotes in the extracellular milieu are infective in vitro and in vivo. Extracellular amastigotes (EAs have a stage-specific surface antigen called Ssp-4, a GPI-anchored glycoprotein that is secreted by the parasites. By immunoprecipitation with the Ssp-4-specific monoclonal antibodies (mAb 2C2 and 1D9, we isolated the glycoprotein from EAs. By mass spectrometry, we identified the core protein of Ssp-4 and evaluated mRNA expression and the presence of Ssp-4 carbohydrate epitopes recognized by mAb1D9. We demonstrated that the carbohydrate epitope recognized by mAb1D9 could promote host cell invasion by EAs. Although infectious EAs express lower amounts of Ssp-4 compared with less-infectious EAs (at the mRNA and protein levels, it is the glycosylation of Ssp-4 (identified by mAb1D9 staining only in infectious strains and recognized by galectin-3 on host cells that is the determinant of EA invasion of host cells. Furthermore, Ssp-4 is secreted by EAs, either free or associated with parasite vesicles, and can participate in host-cell interactions. The results presented here describe the possible role of a carbohydrate moiety of T. cruzi surface glycoproteins in host cell invasion by EA forms, highlighting the potential of these moieties as therapeutic and vaccine targets for the treatment of Chagas’ disease.

  11. A Carbohydrate Moiety of Secreted Stage-Specific Glycoprotein 4 Participates in Host Cell Invasion by Trypanosoma cruzi Extracellular Amastigotes

    Science.gov (United States)

    Florentino, Pilar T. V.; Real, Fernando; Orikaza, Cristina M.; da Cunha, Julia P. C.; Vitorino, Francisca N. L.; Cordero, Esteban M.; Sobreira, Tiago J. P.; Mortara, Renato A.

    2018-01-01

    Trypanosoma cruzi is the etiologic agent of Chagas’ disease. It is known that amastigotes derived from trypomastigotes in the extracellular milieu are infective in vitro and in vivo. Extracellular amastigotes (EAs) have a stage-specific surface antigen called Ssp-4, a GPI-anchored glycoprotein that is secreted by the parasites. By immunoprecipitation with the Ssp-4-specific monoclonal antibodies (mAb) 2C2 and 1D9, we isolated the glycoprotein from EAs. By mass spectrometry, we identified the core protein of Ssp-4 and evaluated mRNA expression and the presence of Ssp-4 carbohydrate epitopes recognized by mAb1D9. We demonstrated that the carbohydrate epitope recognized by mAb1D9 could promote host cell invasion by EAs. Although infectious EAs express lower amounts of Ssp-4 compared with less-infectious EAs (at the mRNA and protein levels), it is the glycosylation of Ssp-4 (identified by mAb1D9 staining only in infectious strains and recognized by galectin-3 on host cells) that is the determinant of EA invasion of host cells. Furthermore, Ssp-4 is secreted by EAs, either free or associated with parasite vesicles, and can participate in host-cell interactions. The results presented here describe the possible role of a carbohydrate moiety of T. cruzi surface glycoproteins in host cell invasion by EA forms, highlighting the potential of these moieties as therapeutic and vaccine targets for the treatment of Chagas’ disease. PMID:29692765

  12. Deep sequencing of the Trypanosoma cruzi GP63 surface proteases reveals diversity and diversifying selection among chronic and congenital Chagas disease patients.

    Science.gov (United States)

    Llewellyn, Martin S; Messenger, Louisa A; Luquetti, Alejandro O; Garcia, Lineth; Torrico, Faustino; Tavares, Suelene B N; Cheaib, Bachar; Derome, Nicolas; Delepine, Marc; Baulard, Céline; Deleuze, Jean-Francois; Sauer, Sascha; Miles, Michael A

    2015-04-01

    Chagas disease results from infection with the diploid protozoan parasite Trypanosoma cruzi. T. cruzi is highly genetically diverse, and multiclonal infections in individual hosts are common, but little studied. In this study, we explore T. cruzi infection multiclonality in the context of age, sex and clinical profile among a cohort of chronic patients, as well as paired congenital cases from Cochabamba, Bolivia and Goias, Brazil using amplicon deep sequencing technology. A 450bp fragment of the trypomastigote TcGP63I surface protease gene was amplified and sequenced across 70 chronic and 22 congenital cases on the Illumina MiSeq platform. In addition, a second, mitochondrial target--ND5--was sequenced across the same cohort of cases. Several million reads were generated, and sequencing read depths were normalized within patient cohorts (Goias chronic, n = 43, Goias congenital n = 2, Bolivia chronic, n = 27; Bolivia congenital, n = 20), Among chronic cases, analyses of variance indicated no clear correlation between intra-host sequence diversity and age, sex or symptoms, while principal coordinate analyses showed no clustering by symptoms between patients. Between congenital pairs, we found evidence for the transmission of multiple sequence types from mother to infant, as well as widespread instances of novel genotypes in infants. Finally, non-synonymous to synonymous (dn:ds) nucleotide substitution ratios among sequences of TcGP63Ia and TcGP63Ib subfamilies within each cohort provided powerful evidence of strong diversifying selection at this locus. Our results shed light on the diversity of parasite DTUs within each patient, as well as the extent to which parasite strains pass between mother and foetus in congenital cases. Although we were unable to find any evidence that parasite diversity accumulates with age in our study cohorts, putative diversifying selection within members of the TcGP63I gene family suggests a link between genetic diversity within this gene

  13. Interclonal variations in the molecular karyotype of Trypanosoma cruzi: chromosome rearrangements in a single cell-derived clone of the G strain.

    Science.gov (United States)

    Lima, Fabio Mitsuo; Souza, Renata Torres; Santori, Fábio Rinaldo; Santos, Michele Fernandes; Cortez, Danielle Rodrigues; Barros, Roberto Moraes; Cano, Maria Isabel; Valadares, Helder Magno Silva; Macedo, Andréa Mara; Mortara, Renato Arruda; da Silveira, José Franco

    2013-01-01

    Trypanosoma cruzi comprises a pool of populations which are genetically diverse in terms of DNA content, growth and infectivity. Inter- and intra-strain karyotype heterogeneities have been reported, suggesting that chromosomal rearrangements occurred during the evolution of this parasite. Clone D11 is a single-cell-derived clone of the T. cruzi G strain selected by the minimal dilution method and by infecting Vero cells with metacyclic trypomastigotes. Here we report that the karyotype of clone D11 differs from that of the G strain in both number and size of chromosomal bands. Large chromosomal rearrangement was observed in the chromosomes carrying the tubulin loci. However, most of the chromosome length polymorphisms were of small amplitude, and the absence of one band in clone D11 in relation to its reference position in the G strain could be correlated to the presence of a novel band migrating above or below this position. Despite the presence of chromosomal polymorphism, large syntenic groups were conserved between the isolates. The appearance of new chromosomal bands in clone D11 could be explained by chromosome fusion followed by a chromosome break or interchromosomal exchange of large DNA segments. Our results also suggest that telomeric regions are involved in this process. The variant represented by clone D11 could have been induced by the stress of the cloning procedure or could, as has been suggested for Leishmania infantum, have emerged from a multiclonal, mosaic parasite population submitted to frequent DNA amplification/deletion events, leading to a 'mosaic' structure with different individuals having differently sized versions of the same chromosomes. If this is the case, the variant represented by clone D11 would be better adapted to survive the stress induced by cloning, which includes intracellular development in the mammalian cell. Karyotype polymorphism could be part of the T. cruzi arsenal for responding to environmental pressure.

  14. ESRD QIP - NHSN Bloodstream Infection - Payment Year 2018

    Data.gov (United States)

    U.S. Department of Health & Human Services — This dataset includes facility details, performance ratio, measure score, and the state and national average measure scores for the NHSN bloodstream infection...

  15. Bloodstream Infections with Mycobacterium tuberculosis among HIV patients

    Centers for Disease Control (CDC) Podcasts

    2010-09-23

    This podcast looks at bloodstream infections with Mycobacterium tuberculosis and other pathogens among outpatients infected with HIV in Southeast Asia. CDC health scientist Kimberly McCarthy discusses the study and why bloodstream infections occur in HIV-infected populations.  Created: 9/23/2010 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 9/23/2010.

  16. Influence of ionizing radiation on Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Szarota, Rosa Maria

    2006-01-01

    Chagas's disease is one of the major public health problems in South America, promoting high prejudice to the local population. Despite the massive efforts to control it, this disease has no cure and presents puzzling unsolved questions. Considering that many researchers have used ionizing radiation to modify protozoans or biomolecules, we investigated the immunological response aspects of susceptible and resistant mice using irradiated parasites. Low radiation doses preserved the reproductive and invasive capacities of the parasite. Both susceptible and resistant animals, after immunization with irradiated parasites produced specific antibodies. After a challenge, the animals presented low parasitaemia, excepting those immunized with the antigen irradiated with higher doses. Using low radiation doses, we were able to selectively isolate trypomastigotes, leading to an improvement in the quality of the immune response, as previously reported when performing complement system assays. These data highlight the importance of selecting trypomastigote forms for immunization against T. cruz; and point towards ionizing radiation as an alternative to achieve this selection, since when this procedure is performed using complement, the subsequent steps are impaired by the difficulties to remove this component from the system. (author)

  17. 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

    essential oil 250 mg/kg (G4, uninfected and untreated (G5, and uninfected and treated with 250 mg/kg of Aloysia triphyla (G6. The infection was conducted using 104 blood T. cruzi trypomastigotes and the treatment began on the 8th day post-infection (dpi through 28 dpi. The parasitemia was determined through optical microscopy every 2 days using 5 μL of blood sampled from the tail. In dpi 14, 21 and 28, the blood sample was obtained from the queue for testing creatine kinase-MB, alanine aminotransferase and creatinine, then animals were euthanized and the heart was removed for histopathological study. Results. The essential oil of lemon verbena produced a significant reduction of the parasitemia, 85.4% with the peak at a the dose of 250 mg/ kg. It was also observed a reduction in the number of amastigotes and inflammatory infiltrates in the heart. The creatine kinase-MB plasma levels also decreased at dpi 28 as a result of such treatment. Conclusions. Under experimental conditions, the essential oil of Aloysia triphylla (lemon verbena has in vivo anti-Trypanosoma cruzi effect in mice.

  18. When Prostate Cancer Circulates in the Bloodstream

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    Virginie Vlaeminck-Guillem

    2015-10-01

    Full Text Available Management of patients with prostate cancer is currently based on imperfect clinical, biological, radiological and pathological evaluation. Prostate cancer aggressiveness, including metastatic potential, remains difficult to accurately estimate. In an attempt to better adapt therapeutics to an individual (personalized medicine, reliable evaluation of the intrinsic molecular biology of the tumor is warranted, and particularly for all tumor sites (primary tumors and secondary sites at any time of the disease progression. As a consequence of their natural tendency to grow (passive invasion or as a consequence of an active blood vessel invasion by metastase-initiating cells, tumors shed various materials into the bloodstream. Major efforts have been recently made to develop powerful and accurate methods able to detect, quantify and/or analyze all these circulating tumor materials: circulating tumors cells, disseminating tumor cells, extracellular vesicles (including exosomes, nucleic acids, etc. The aim of this review is to summarize current knowledge about these circulating tumor materials and their applications in translational research.

  19. 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

  20. Efecto anti-Trypanosoma cruzi del aceite esencial de Cymbopogon citratus (DC Stapf (hierba luisa en ratones Balb/c

    Directory of Open Access Journals (Sweden)

    Juan Rojas

    2012-01-01

    Full Text Available Objetivo: Determinar la actividad anti-Trypanosoma cruzi in vivo del aceite esencial de Cymbopogon citratus en ratones Balb/c. Diseño: Estudio experimental, prospectivo. Institución: Instituto de Investigaciones Clínicas e Instituto de Medicina Tropical de la Facultad de Medicina de la Universidad Nacional Mayor de San Marcos, Lima, Perú. Material biológico: Aceite esencial de Cymbopogon citratus; ratones albinos Balb/c. Intervenciones: Los animales fueron asignados aleatoriamente a seis grupos de 15 ratones cada uno: infectados y no tratados (G1, infectados y tratados con benznidazol 100 mg/kg (G2, infectados y tratados con aceite esencial de Cymbopogon citratus 100 mg/kg y 250 mg/kg (G3 y G4, respectivamente, no infectados y no tratados (G5, y no infectados y tratados con 250 mg de Cymbopogon citratus (G6. La infección con T. cruzi se realizó con 10(4 trypomastigotes sanguíneos y el tratamiento empezó en el 8º día post infección (dpi hasta el 28° dpi. La parasitemia se determinó con microscopia óptica cada dos días en 5 µL de sangre de la cola. En el 14°, 21° y 28° dpi, cinco animales de cada grupo fueron sacrificados y se removió el corazón para estudio histopatológico. Principales medidas de resultados: Parasitemia, número de nidos de amastigotes e infiltrados inflamatorios. Resultados: El aceite esencial de Cymbopogon citratus 250 mg/kg/día produjo una reducción significativa en el pico de parasitemia desde 113,92 ± 25,66 hasta 74,60 ± 12,37 tripomastigotes/mL (p < 0,05. Con 100 mg/kg/día se produjo una reducción hasta 77,40 ± 14,93 tripomastigotes/ mL (p < 0,05. También redujo el número de amastigotes y de infiltrados inflamatorios en el corazón. Conclusiones: El aceite esencial de Cymbopogon citratus tuvo efecto anti-Trypanosoma cruzi en ratones Balb/c en lo referente a la disminución de la parasitemia, el número de nidos de amastigotes y los resultados inflamatorios.

  1. Influence of ionizing radiation on Trypanosoma cruzi; Influencia da radiacao ionizante sobre o Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Szarota, Rosa Maria

    2006-07-01

    Chagas's disease is one of the major public health problems in South America, promoting high prejudice to the local population. Despite the massive efforts to control it, this disease has no cure and presents puzzling unsolved questions. Considering that many researchers have used ionizing radiation to modify protozoans or biomolecules, we investigated the immunological response aspects of susceptible and resistant mice using irradiated parasites. Low radiation doses preserved the reproductive and invasive capacities of the parasite. Both susceptible and resistant animals, after immunization with irradiated parasites produced specific antibodies. After a challenge, the animals presented low parasitaemia, excepting those immunized with the antigen irradiated with higher doses. Using low radiation doses, we were able to selectively isolate trypomastigotes, leading to an improvement in the quality of the immune response, as previously reported when performing complement system assays. These data highlight the importance of selecting trypomastigote forms for immunization against T. cruz; and point towards ionizing radiation as an alternative to achieve this selection, since when this procedure is performed using complement, the subsequent steps are impaired by the difficulties to remove this component from the system. (author)

  2. Influence of ionizing radiation on Trypanosoma cruzi; Influencia da radiacao ionizante sobre o Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Szarota, Rosa Maria

    2006-07-01

    Chagas's disease is one of the major public health problems in South America, promoting high prejudice to the local population. Despite the massive efforts to control it, this disease has no cure and presents puzzling unsolved questions. Considering that many researchers have used ionizing radiation to modify protozoans or biomolecules, we investigated the immunological response aspects of susceptible and resistant mice using irradiated parasites. Low radiation doses preserved the reproductive and invasive capacities of the parasite. Both susceptible and resistant animals, after immunization with irradiated parasites produced specific antibodies. After a challenge, the animals presented low parasitaemia, excepting those immunized with the antigen irradiated with higher doses. Using low radiation doses, we were able to selectively isolate trypomastigotes, leading to an improvement in the quality of the immune response, as previously reported when performing complement system assays. These data highlight the importance of selecting trypomastigote forms for immunization against T. cruz; and point towards ionizing radiation as an alternative to achieve this selection, since when this procedure is performed using complement, the subsequent steps are impaired by the difficulties to remove this component from the system. (author)

  3. Detection of Trypanosoma cruzi antibodies in multitransfused patients in Colombia

    Directory of Open Access Journals (Sweden)

    Mauricio Beltrán

    2017-09-01

    Conclusions: The results of this study showed a low frequency of T. cruzi infection in multitransfused patients, suggesting that the risk of transfusion infection in Colombia is low. Known risk factors for transfusion-related infection were not associated with the presence of anti-T. cruzi antibodies.

  4. Neonatal bloodstream infections in a pediatric hospital in Vietnam

    DEFF Research Database (Denmark)

    Kruse, Alexandra Yasmin; Thieu Chuong, Do Huu; Phuong, Cam Ngoc

    2013-01-01

    Septicemia and bloodstream infections (BSIs) are major causes of neonatal morbidity and mortality in developing countries. We prospectively recorded all positive blood cultures (BSI) among neonates admitted consecutively to a tertiary pediatric hospital in Vietnam during a 12-month period. Among...

  5. The changing epidemiology of Staphylococcus aureus bloodstream infection

    DEFF Research Database (Denmark)

    Laupland, K.B.; Lyytikäinen, O.; Søgaard, Mette

    2013-01-01

    Clin Microbiol Infect ABSTRACT: Although the epidemiology of Staphylococcus aureus bloodstream infection (BSI) has been changing, international comparisons are lacking. We sought to determine the incidence of S. aureus BSI and assess trends over time and by region. Population-based surveillance w...

  6. What controls glycolysis in bloodstream form Trypanosoma brucei?

    NARCIS (Netherlands)

    Bakker, B.M.; Michels, P.A.M.; Opperdoes, F.R.; Westerhoff, H.V.

    1999-01-01

    On the basis of the experimentally determined kinetic properties of the trypanosomal enzymes, the question is addressed of which step limits the glycolytic flux in bloodstream form Trypanosoma brucei. There appeared to be no single answer; in the physiological range, control shifted between the

  7. Pathogenicity of bloodstream and cerebrospinal fluid forms of ...

    African Journals Online (AJOL)

    kemrilib

    brain barrier and invade the central nervous system (CNS). However, it is not clear whether bloodstream forms (BSF) of T.b.rhodesiense differ in biological characteristics from ... carried out to compare the pathogenicity of CSF and BSF of T.b. rhodesiense parasites in ..... Swiss white of the same sex, the difference in survival ...

  8. Activity in vitro and in vivo against Trypanosoma cruzi of a furofuran lignan isolated from Piper jericoense.

    Science.gov (United States)

    García-Huertas, Paola; Olmo, Francisco; Sánchez-Moreno, Manuel; Dominguez, Jorge; Chahboun, Rachid; Triana-Chávez, Omar

    2018-06-01

    Piperaceae species are abundant in the tropics and are important components of secondary vegetation. Many of these plants have received considerable attention due to their wide range of biological activities. Here, the trypanocidal activity of extracts and fractions with different polarities obtained from Colombian Piper jericoense plant was evaluated. A furofuran lignan, (1S,3aS,4S,6aS)-1-(3',4'-dimethoxyphenyl)-4-(3″,4″-methylendioxyphenyl)hexahydrofuro[3,4-c]furan, (1), was isolated from Colombian Piper jericoense leaves ethyl acetate extract. Its relative configuration at the stereogenic centers was established on the basis of various spectroscopic analyses, including 1D- (1H, 13C, and DEPT) and 2D-NMR (COSY, NOESY, HMQC and HMBC) and a 2D INADEQUATE NMR experiment as well as by comparison of their spectral data with those of related compounds such as (+)-Kobusin (2). The activity against Trypanosoma cruzi indicated that compound 1 was active against all parasite forms (epimastigote, amastigote and trypomastigote) and presented lower toxicity than the reference drug, benznidazole (Bz), evidenced by a selective index of 18.4 compared to that of Bz, which was 6.7. Moreover, this compound inhibited the infectious process, and it was active in infected mice in the acute phase. This compound significantly inhibited the T. cruzi Fe-SOD enzyme, whereas Cu/Zn-SOD from human cells was not affected. Ultrastructural analyses, together with metabolism-excretion studies in the parasite, were also performed to identify the possible mechanism of action of the tested compound. Interestingly, the lignan affected the parasite structure, but it did not alter the energetic metabolism. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. TcI, TcII and TcVI Trypanosoma cruzi samples from Chagas disease patients with distinct clinical forms and critical analysis of in vitro and in vivo behavior, response to treatment and infection evolution in murine model.

    Science.gov (United States)

    Oliveira, Maykon Tavares de; Branquinho, Renata Tupinambá; Alessio, Gláucia Diniz; Mello, Carlos Geraldo Campos; Nogueira-de-Paiva, Nívia Carolina; Carneiro, Cláudia Martins; Toledo, Max Jean de Ornelas; Reis, Alexandre Barbosa; Martins-Filho, Olindo Assis Martins; Lana, Marta de

    2017-03-01

    The clonal evolution of Trypanosoma cruzi sustains scientifically the hypothesis of association between parasite's genetic, biological behavior and possibly the clinical aspects of Chagas disease in patients from whom they were isolated. This study intended to characterize a range of biological properties of TcI, TcII and TcVI T. cruzi samples in order to verify the existence of these associations. Several biological features were evaluated, including in vitro epimastigote-growth, "Vero"cells infectivity and growth, along with in vivo studies of parasitemia, polymorphism of trypomastigotes, cardiac inflammation, fibrosis and response to treatment by nifurtimox during the acute and chronic murine infection. The global results showed that the in vitro essays (acellular and cellular cultures) TcII parasites showed higher values for all parameters (growth and infectivity) than TcVI, followed by TcI. In vivo TcII parasites were more virulent and originated from patients with severe disease. Two TcII isolates from patients with severe pathology were virulent in mice, while the isolate from a patient with the indeterminate form of the disease caused mild infection. The only TcVI sample, which displayed low values in all parameters evaluated, was also originated of an indeterminate case of Chagas disease. Response to nifurtimox was not associated to parasite genetic and biology, as well as to clinical aspects of human disease. Although few number of T. cruzi samples have been analyzed, a discreet correlation between parasite genetics, biological behavior in vitro and in vivo (murine model) and the clinical form of human disease from whom the samples were isolated was verified. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Performance of TcI/TcVI/TcII Chagas-Flow ATE-IgG2a for universal and genotype-specific serodiagnosis of Trypanosoma cruzi infection.

    Directory of Open Access Journals (Sweden)

    Glaucia Diniz Alessio

    2017-03-01

    Full Text Available Distinct Trypanosoma cruzi genotypes have been considered relevant for patient management and therapeutic response of Chagas disease. However, typing strategies for genotype-specific serodiagnosis of Chagas disease are still unavailable and requires standardization for practical application. In this study, an innovative TcI/TcVI/TcII Chagas Flow ATE-IgG2a technique was developed with applicability for universal and genotype-specific diagnosis of T. cruzi infection. For this purpose, the reactivity of serum samples (percentage of positive fluorescent parasites-PPFP obtained from mice chronically infected with TcI/Colombiana, TcVI/CL or TcII/Y strain as well as non-infected controls were determined using amastigote-AMA, trypomastigote-TRYPO and epimastigote-EPI in parallel batches of TcI, TcVI and TcII target antigens. Data demonstrated that "α-TcII-TRYPO/1:500, cut-off/PPFP = 20%" presented an excellent performance for universal diagnosis of T. cruzi infection (AUC = 1.0, Se and Sp = 100%. The combined set of attributes "α-TcI-TRYPO/1:4,000, cut-off/PPFP = 50%", "α-TcII-AMA/1:1,000, cut-off/PPFP = 40%" and "α-TcVI-EPI/1:1,000, cut-off/PPFP = 45%" showed good performance to segregate infections with TcI/Colombiana, TcVI/CL or TcII/Y strain. Overall, hosts infected with TcI/Colombiana and TcII/Y strains displayed opposite patterns of reactivity with "α-TcI TRYPO" and "α-TcII AMA". Hosts infected with TcVI/CL strain showed a typical interweaved distribution pattern. The method presented a good performance for genotype-specific diagnosis, with global accuracy of 69% when the population/prototype scenario include TcI, TcVI and TcII infections and 94% when comprise only TcI and TcII infections. This study also proposes a receiver operating reactivity panel, providing a feasible tool to classify serum samples from hosts infected with distinct T. cruzi genotypes, supporting the potential of this method for universal and genotype-specific diagnosis

  11. Nuclear distribution of the Trypanosoma cruzi RNA Pol I subunit RPA31 during growth and metacyclogenesis, and characterization of its nuclear localization signal.

    Science.gov (United States)

    Canela-Pérez, Israel; López-Villaseñor, Imelda; Cevallos, Ana María; Hernández, Roberto

    2018-03-01

    Trypanosoma cruzi is the aetiologic agent of Chagas disease. Our research group studies ribosomal RNA (rRNA) gene transcription and nucleolus dynamics in this species of trypanosomes. RPA31 is an essential subunit of RNA polymerase I (Pol I) whose presence is apparently restricted to trypanosomes. Using fluorescent-tagged versions of this protein (TcRPA31-EGFP), we describe its nuclear distribution during growth and metacyclogenesis. Our findings indicate that TcRPA31-EGFP alters its nuclear presence from concentrated nucleolar localization in exponentially growing epimastigotes to a dispersed granular distribution in the nucleoplasm of stationary epimastigotes and metacyclic trypomastigotes. These changes likely reflect a structural redistribution of the Pol I transcription machinery in quiescent cellular stages where downregulation of rRNA synthesis is known to occur. In addition, and related to the nuclear internalization of this protein, the presence of a classical bipartite-type nuclear localization signal was identified towards its C-terminal end. The functionality of this motif was demonstrated by its partial or total deletion in recombinant versions of the tagged fluorescent protein. Moreover, ivermectin inhibited the nuclear localization of the labelled chimaera, suggesting the involvement of the importin α/β transport system.

  12. 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.

  13. Repositioning FDA Drugs as Potential Cruzain Inhibitors from Trypanosoma cruzi: Virtual Screening, In Vitro and In Vivo Studies

    Directory of Open Access Journals (Sweden)

    Isidro Palos

    2017-06-01

    Full Text Available Chagas disease (CD is a neglected disease caused by the parasite Trypanosoma cruzi, which affects underdeveloped countries. The current drugs of choice are nifurtimox and benznidazole, but both have severe adverse effects and less effectivity in chronic infections; therefore, the need to discover new drugs is essential. A computer-guided drug repositioning method was applied to identify potential FDA drugs (approved and withdrawn as cruzain (Cz inhibitors and trypanocidal effects were confirmed by in vitro and in vivo studies. 3180 FDA drugs were virtually screened using a structure-based approach. From a first molecular docking analysis, a set of 33 compounds with the best binding energies were selected. Subsequent consensus affinity binding, ligand amino acid contact clustering analysis, and ranked position were used to choose four known pharmacological compounds to be tested in vitro. Mouse blood samples infected with trypomastigotes from INC-5 and NINOA strains were used to test the trypanocidal effect of four selected compounds. Among these drugs, one fibrate antilipemic (etofyllin clofibrate and three β-lactam antibiotics (piperacillin, cefoperazone, and flucloxacillin showed better trypanocidal effects (LC50 range 15.8–26.1 μg/mL in comparison with benznidazole and nifurtimox (LC50 range 33.1–46.7 μg/mL. A short-term in vivo evaluation of these compounds showed a reduction of parasitemia in infected mice (range 90–60% at 6 h, but this was low compared to benznidazole (50%. This work suggests that four known FDA drugs could be used to design and obtain new trypanocidal agents.

  14. Bloodstream Infections in a Neonatal Intensive Care Unit

    OpenAIRE

    Mehmet Sah Ipek

    2016-01-01

    Aim: To determine the pattern of bloodstream infections (BSIs) and antimicrobial susceptibility of pathogens in a neonatal intensive care unit (NICU).Material and Method: Positive hemoculture of neonates diagnosed with nosocomial sepsis from March 2011 to March 2014 in the NICU of Diyarbakir Maternity and Children%u2019s Hospital, in the southeastern region of Anatolia, Turkey, were retrospectively reviewed. Results: A total of 148 pathogens were isolated in 142 neonates. The most common micr...

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

    Directory of Open Access Journals (Sweden)

    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

  16. EPIDEMIOLOGÍA MOLECULAR DE TRYPANOSOMA CRUZI

    Directory of Open Access Journals (Sweden)

    Felipe Guhl

    2013-01-01

    Full Text Available La enfermedad de Chagas causada por el parásito Trypanosoma cruzi es una zoonosis compleja, ampliamente distribuida en el continente americano. La infección puede ser adquirida a través de las heces de insectos triatominos, transfusión de sangre, trasplante de órganos, vía oral, por transmisión congénita y por accidentes de laboratorio. El completo entendimiento de la etiología y epidemiología de la enfermedad de Chagas a través de su distribución geográfica es complejo y permanece bajo intensa investigación hasta la actualidad. Los recientes estudios sobre la variabilidad genética del parásito han dado nuevas luces de los diferentes escenarios de los ciclos de transmisión de la enfermedad y su patogénesis en humanos. El propósito principal para la caracterización molecular de T.cruzi y sus múltiples genotipos está dirigido hacia su asociación con la clínica y la patogenesis de la enfermedad, así como al esclarecimiento de los diferentes escenarios de transmisión y los aspectos coevolutivos relacionados con reservorios e insectos vectores. La caracterización molecular de los diferentes aislamientos a partir de humanos, insectos y reservorios, ha permitido identificar la amplia variabilidad genética del parásito, abriendo nuevos caminos hacia la búsqueda de nuevos blancos terapéuticos y pruebas diagnósticas más específicas que contribuyan a mitigar la enfermedad de Chagas.

  17. Seropositivity for Trypanosoma cruzi in domestic dogs from Sonora, Mexico.

    Science.gov (United States)

    Arce-Fonseca, Minerva; Carrillo-Sánchez, Silvia C; Molina-Barrios, Ramón M; Martínez-Cruz, Mariana; Cedillo-Cobián, Jesús R; Henao-Díaz, Yuly A; Rodríguez-Morales, Olivia

    2017-09-05

    Chagas disease is an important health problem in Latin America due to its incapacitating effects and associated mortality. Studies on seropositivity for Trypanosoma cruzi in Mexican dogs have demonstrated a direct correlation between seropositivity in humans and dogs, which can act as sentinels for the disease in this region. The objective of this study was to determine the seropositivity for T.cruzi infection in dogs from Sonora, a northern borderstate of Mexico. Responsible pet owners were selected at random from an urban area of Empalme municipality, Sonora, Mexico, and from there, 180 dog samples were collected. Anti-T. cruzi antibodies were determined using the enzyme-linked immunosorbent assay (ELISA) method. Reactive ELISA sera were processed by indirect immunofluorescence to confirm the presence of anti-T. cruzi antibodies. For the statistical analysis, chi-square tests were conducted. Dogs' sera showed a seropositivity rate of 4.44%. The rate of seropositivity was not associated with the dogs' age, sex, or socioeconomics pertaining to the geographical area. One sample (1/180, 0.55%) showed the acute state of the disease. The study found a presence of anti-T. cruzi antibodies in dogs in this area, which suggests vector transmission. There is a need for active surveillance programs throughout the state of Sonora and vector control strategies should also be implemented in endemic regions.

  18. Risk of vancomycin-resistant enterococci bloodstream infection among patients colonized with vancomycin-resistant enterococci

    Directory of Open Access Journals (Sweden)

    Ahu Kara

    2015-01-01

    Conclusion: In conclusion, our study found that 1.55% of vancomycin-resistant enterococci-colonized children had developed vancomycin-resistant enterococci bloodstream infection among the pediatric intensive care unit and hematology/oncology patients; according to our findings, we suggest that immunosupression is the key point for developing vancomycin-resistant enterococci bloodstream infections.

  19. A fresh look at polymicrobial bloodstream infection in cancer patients.

    Directory of Open Access Journals (Sweden)

    Cristina Royo-Cebrecos

    Full Text Available To assess the current incidence, clinical features, risk factors, aetiology, antimicrobial resistance and outcomes of polymicrobial bloodstream infection (PBSI in patients with cancer.All prospectively collected episodes of PBSI in hospitalised patients were compared with episodes of monomicrobial bloodstream infection (MBSI between 2006 and 2015.We identified 194 (10.2% episodes of PBSI and 1702 MBSI (89.8%. The presence of cholangitis, biliary stenting, neutropenia, corticosteroids, neutropenic enterocolitis and other abdominal infections were identified as risk factors for PBSI. Overall, Gram-negative organisms were the most frequent aetiology, but Enterococcus spp. were especially frequent causes of Gram-positive PBSI (30.8%. Multidrug-resistant (MDR organisms were more commonly found in PBSI than in MBSI (20.6% vs 12.9%; p = 0.003. Compared to patients with MBSI, those with PBSI presented with higher early (15% vs 1.4%; p = 0.04 and overall (32% vs 20.9%; p<0.001 case-fatality rates. Risk factors for overall case-fatality were a high-risk MASCC (Multinational Association of Supportive Care in Cancer index score, corticosteroid use, persistent bacteraemia and septic shock.PBSI is a frequent complication in patients with cancer and is responsible for high mortality rates. Physicians should identify patients at risk for PBSI and provide empiric antibiotic therapy that covers the most frequent pathogens involved in these infections, including MDR strains.

  20. von Willebrand factor, Jedi knight of the bloodstream.

    Science.gov (United States)

    Springer, Timothy A

    2014-08-28

    When blood vessels are cut, the forces in the bloodstream increase and change character. The dark side of these forces causes hemorrhage and death. However, von Willebrand factor (VWF), with help from our circulatory system and platelets, harnesses the same forces to form a hemostatic plug. Force and VWF function are so closely intertwined that, like members of the Jedi Order in the movie Star Wars who learn to use "the Force" to do good, VWF may be considered the Jedi knight of the bloodstream. The long length of VWF enables responsiveness to flow. The shape of VWF is predicted to alter from irregularly coiled to extended thread-like in the transition from shear to elongational flow at sites of hemostasis and thrombosis. Elongational force propagated through the length of VWF in its thread-like shape exposes its monomers for multimeric binding to platelets and subendothelium and likely also increases affinity of the A1 domain for platelets. Specialized domains concatenate and compact VWF during biosynthesis. A2 domain unfolding by hydrodynamic force enables postsecretion regulation of VWF length. Mutations in VWF in von Willebrand disease contribute to and are illuminated by VWF biology. I attempt to integrate classic studies on the physiology of hemostatic plug formation into modern molecular understanding, and point out what remains to be learned. © 2014 by The American Society of Hematology.

  1. Central venous catheter-related bloodstream infections in cancer patients

    International Nuclear Information System (INIS)

    Butt, T.; Afzal, R.K.; Ahmad, R.N.; Hussain, I.; Anwar, M.

    2004-01-01

    Objective: To determine the frequency of central venous catheter-related bloodstream infections (CR-BSI) in cancer patients and the antimicrobial susceptibility pattern of the isolates. Subjects and Methods: Cancer patients requiring short or long-term central venous catheterization at the time of admission or thereafter were included. Catheter tips on removal were cultured quantitatively; specimens of blood and pus were cultured qualitatively. Isolates were identified and antimicrobial susceptibility testing was performed by standard techniques. Results: Eighty-nine patients were included in the study. The frequency of CR-BSI was 17%. Out of the 19 organisms isolated, 10 (53%) were Gram-positive cocci, 8 (42%) were Gram-negative rods and 1 (5%) was a fungus. Coagulase negative staphylococci (27%) were the predominant pathogens. Among the staphylococci, 46% of the isolates were methicillin-resistant. All Gram-positive isolates were susceptive to glycopeptides. Gram-negative rods were resistant to most of the commonly used antimicrobial groups. Conclusion: Central venous catheter is an important source of bloodstream infections in cancer patients. Most of the infections are caused by Gram-positive cocci. Rigorous infection control measures and continuous surveillance is required to curb the frequency of these infections. (author)

  2. Histometría de la glándula sublingual de ratones (Mus musculus machos y hembras infectados con la cepa RAL del parásito de Chagas, Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Sérgio de Albuquerque

    2008-06-01

    with the RAL strain of T. cruzi, according to the sex. Swiss mice (Mus musculus were inoculated with 2x104 blood trypomastigotes of the RAL strain of T. cruzi. in the peak of the parasitemia (12th day the mice were sacrificed, and the sublingual glands were fixed in ALFAC. HE-stained histological sections were evaluated histometrically. The parasitemia was higher in females. Histopatologically, acini of the infected animals were smaller, with scanty production of secretion, and smaller striated ducts. The nuclei of the demilunes were smaller and showed amastigote nests in the cytoplasm. Karyometrically, nuclei of the acini, demilunes and striated ducts were smaller in the infected mice. Stereologically, it was observed that relative volumes of acini and ducts were smaller and, inversely, relative volumen were greater for the conjunctive tissue in the infected males. The surface densities of acini and ducts were bigger and the diameter and thickness of the wall were smaller in this group. On the other hand, relative volume of acini was smaller and those of the ducts and conjunctive tissue were bigger in the infected females. The diameter and thickness of the wall of acini were smaller, and those of the striated ducts were bigger in this group. The RAL strain of T. cruzi caused general atrophy in the sublingual gland, with numerous nests of parasites in the glandular parenchyma. Rev. Biol. Trop. 56 (2: 459-471. Epub 2008 June 30.

  3. Candida bloodstream infection: a clinical microbiology laboratory perspective.

    Science.gov (United States)

    Pongrácz, Júlia; Kristóf, Katalin

    2014-09-01

    The incidence of Candida bloodstream infection (BSI) has been on the rise in several countries worldwide. Species distribution is changing; an increase in the percentage of non-albicans species, mainly fluconazole non-susceptible C. glabrata was reported. Existing microbiology diagnostic methods lack sensitivity, and new methods need to be developed or further evaluation for routine application is necessary. Although reliable, standardized methods for antifungal susceptibility testing are available, the determination of clinical breakpoints remains challenging. Correct species identification is important and provides information on the intrinsic susceptibility profile of the isolate. Currently, acquired resistance in clinical Candida isolates is rare, but reports indicate that it could be an issue in the future. The role of the clinical microbiology laboratory is to isolate and correctly identify the infective agent and provide relevant and reliable susceptibility data as soon as possible to guide antifungal therapy.

  4. Relationship between neighborhood poverty rate and bloodstream infections in the critically ill.

    Science.gov (United States)

    Mendu, Mallika L; Zager, Sam; Gibbons, Fiona K; Christopher, Kenneth B

    2012-05-01

    Poverty is associated with increased risk of chronic illness, but its contribution to bloodstream infections is not well-defined. We performed a multicenter observational study of 14,657 patients, aged 18 yrs or older, who received critical care and had blood cultures drawn between 1997 and 2007 in two hospitals in Boston, Massachusetts. Data sources included 1990 U.S. Census and hospital administrative data. Census tracts were used as the geographic units of analysis. The exposure of interest was neighborhood poverty rate categorized as 40%. Neighborhood poverty rate is the percentage of residents with income below the federal poverty line. The primary end point was bloodstream infection occurring 48 hrs before critical care initiation to 48 hrs after. Associations between neighborhood poverty rate and bloodstream infection were estimated by logistic regression models. Adjusted odds ratios were estimated by multivariable logistic regression models. Two thousand four-hundred thirty-five patients had bloodstream infections. Neighborhood poverty rate was a strong predictor of risk of bloodstream infection, with a significant risk gradient across neighborhood poverty rate quintiles. After multivariable analysis, neighborhood poverty rate in the highest quintiles (20%-40% and >40%) were associated with a 26% and 49% increase in bloodstream infection risk, respectively, relative to patients with neighborhood poverty rate of poverty rate, a proxy for decreased socioeconomic status, appears to be associated with risk of bloodstream infection among patients who receive critical care.

  5. Antimicrobial resistance predicts death in Tanzanian children with bloodstream infections: a prospective cohort study

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    Msangi Viola

    2007-05-01

    Full Text Available Abstract Background Bloodstream infection is a common cause of hospitalization, morbidity and death in children. The impact of antimicrobial resistance and HIV infection on outcome is not firmly established. Methods We assessed the incidence of bloodstream infection and risk factors for fatal outcome in a prospective cohort study of 1828 consecutive admissions of children aged zero to seven years with signs of systemic infection. Blood was obtained for culture, malaria microscopy, HIV antibody test and, when necessary, HIV PCR. We recorded data on clinical features, underlying diseases, antimicrobial drug use and patients' outcome. Results The incidence of laboratory-confirmed bloodstream infection was 13.9% (255/1828 of admissions, despite two thirds of the study population having received antimicrobial therapy prior to blood culture. The most frequent isolates were klebsiella, salmonellae, Escherichia coli, enterococci and Staphylococcus aureus. Furthermore, 21.6% had malaria and 16.8% HIV infection. One third (34.9% of the children with laboratory-confirmed bloodstream infection died. The mortality rate from Gram-negative bloodstream infection (43.5% was more than double that of malaria (20.2% and Gram-positive bloodstream infection (16.7%. Significant risk factors for death by logistic regression modeling were inappropriate treatment due to antimicrobial resistance, HIV infection, other underlying infectious diseases, malnutrition and bloodstream infection caused by Enterobacteriaceae, other Gram-negatives and candida. Conclusion Bloodstream infection was less common than malaria, but caused more deaths. The frequent use of antimicrobials prior to blood culture may have hampered the detection of organisms susceptible to commonly used antimicrobials, including pneumococci, and thus the study probably underestimates the incidence of bloodstream infection. The finding that antimicrobial resistance, HIV-infection and malnutrition predict fatal

  6. Early Trypanosoma cruzi Infection Reprograms Human Epithelial Cells

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    María Laura Chiribao

    2014-01-01

    Full Text Available Trypanosoma cruzi, the causative agent of Chagas disease, has the peculiarity, when compared with other intracellular parasites, that it is able to invade almost any type of cell. This property makes Chagas a complex parasitic disease in terms of prophylaxis and therapeutics. The identification of key host cellular factors that play a role in the T. cruzi invasion is important for the understanding of disease pathogenesis. In Chagas disease, most of the focus is on the response of macrophages and cardiomyocytes, since they are responsible for host defenses and cardiac lesions, respectively. In the present work, we studied the early response to infection of T. cruzi in human epithelial cells, which constitute the first barrier for establishment of infection. These studies identified up to 1700 significantly altered genes regulated by the immediate infection. The global analysis indicates that cells are literally reprogrammed by T. cruzi, which affects cellular stress responses (neutrophil chemotaxis, DNA damage response, a great number of transcription factors (including the majority of NFκB family members, and host metabolism (cholesterol, fatty acids, and phospholipids. These results raise the possibility that early host cell reprogramming is exploited by the parasite to establish the initial infection and posterior systemic dissemination.

  7. 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.

  8. Anti-Trypanosoma cruzi antibody detection in eastern Andalusia (Spain).

    Science.gov (United States)

    Marín, Clotilde; Concha-Valdez, Fanny; Cañas, Rocío; Gutiérrez-Sánchez, Ramón; Sánchez-Moreno, Manuel

    2014-03-01

    Chagas disease caused by the protozoan haemoflagellate Trypanosoma cruzi is no longer found exclusively in Latin America; the disease is occurring in Europe, and Spain is the country with the highest prevalence. Our aim was to detect anti-T. cruzi antibodies in blood donors from southeast Spain, and we performed eight serological diagnostic assays on each of 550 blood samples collected in March-June 2010. Two in-house ELISA methods were used to test against a parasite lysate (ELISA-H) and the semi-purified superoxide dismutase excreted by T. cruzi (ELISA-SODe); we also used the Western blot technique against the same antigen (WB-SODe), indirect immunofluorescence (IFA) and four commercial tests. The serological test results showed a range of seroprevalence values, the lowest being 1.1%, determined by IFA and two commercial tests (Ab rapid and Chagascreen); other values were: 1.3% (commercial ELISA [Chagas ELISA IgG+IgM]); 2.1% (immunochromatographic test [Stick Chagas]); 2.7% (ELISA-H); 4.0% (WB-SODe); and 4.2%, the highest value (ELISA-SODe). The excellent specificity of SODe antigen for the detection of antibodies to T. cruzi in donors lead us to affirm that the serological test performed with this biomarker could provide a useful screening and confirmatory test method for cases of Chagas disease.

  9. Dasypus novemcinctus infestado con schizotrypanum cruzi en condiciones naturales

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    Augusto Corredor Arjona

    1963-04-01

    Full Text Available The present publication is the first of a series on Chagas disease in the region of Pizarreal, Municipality of Patios, department of North Santander, Colombia. The authors describe the second case in Colombia of Dasypus nouemcinctus infected in natural form by Schizotrypanum cruzi.

  10. 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.

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

    Science.gov (United States)

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

    2015-10-22

    Chagas disease (caused by Trypanosoma cruzi) is the most important neglected tropical disease (NTD) in Latin America, infecting an estimated 5.7 million people in the 21 countries where it is endemic. It is one of the NTDs targeted for control and elimination by the 2020 London Declaration goals, with the first goal being to interrupt intra-domiciliary vector-borne T. cruzi transmission. A key question in domestic T. cruzi transmission is the role that synanthropic animals play in T. cruzi transmission to humans. Here, we ask, (1) do synanthropic animals need to be targeted in Chagas disease prevention policies?, and (2) how does the presence of animals affect the efficacy of vector control? We developed a simple mathematical model to simulate domestic vector-borne T. cruzi transmission and to specifically examine the interaction between the presence of synanthropic animals and effects of vector control. We used the model to explore how the interactions between triatomine bugs, humans and animals impact the number and proportion of T. cruzi-infected bugs and humans. We then examined how T. cruzi dynamics change when control measures targeting vector abundance are introduced into the system. We found that the presence of synanthropic animals slows the speed of T. cruzi transmission to humans, and increases the sensitivity of T. cruzi transmission dynamics to vector control measures at comparable triatomine carrying capacities. However, T. cruzi transmission is amplified when triatomine carrying capacity increases with the abundance of syntathoropic hosts. Our results suggest that in domestic T. cruzi transmission scenarios where no vector control measures are in place, a reduction in synanthropic animals may slow T. cruzi transmission to humans, but it would not completely eliminate transmission. To reach the 2020 goal of interrupting intra-domiciliary T. cruzi transmission, it is critical to target vector populations. Additionally, where vector control measures

  12. Trypanosoma cruzi infection is a potent risk factor for non-alcoholic steatohepatitis enhancing local and systemic inflammation associated with strong oxidative stress and metabolic disorders.

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    Luisina I Onofrio

    2015-02-01

    Full Text Available The immune mechanisms underlying experimental non-alcoholic steatohepatitis (NASH, and more interestingly, the effect of T. cruzi chronic infection on the pathogenesis of this metabolic disorder are not completely understood.We evaluated immunological parameters in male C57BL/6 wild type and TLR4 deficient mice fed with a standard, low fat diet, LFD (3% fat as control group, or a medium fat diet, MFD (14% fat in order to induce NASH, or mice infected intraperitoneally with 100 blood-derived trypomastigotes of Tulahuen strain and also fed with LFD (I+LFD or MFD (I+MFD for 24 weeks. We demonstrated that MFD by itself was able to induce NASH in WT mice and that parasitic infection induced marked metabolic changes with reduction of body weight and steatosis revealed by histological studies. The I+MFD group also improved insulin resistance, demonstrated by homeostasis model assessment of insulin resistance (HOMA-IR analysis; although parasitic infection increased the triglycerides and cholesterol plasma levels. In addition, hepatic M1 inflammatory macrophages and cytotoxic T cells showed intracellular inflammatory cytokines which were associated with high levels of IL6, IFNγ and IL17 plasmatic cytokines and CCL2 chemokine. These findings correlated with an increase in hepatic parasite load in I+MFD group demonstrated by qPCR assays. The recruitment of hepatic B lymphocytes, NK and dendritic cells was enhanced by MFD, and it was intensified by parasitic infection. These results were TLR4 signaling dependent. Flow cytometry and confocal microscopy analysis demonstrated that the reactive oxygen species and peroxinitrites produced by liver inflammatory leukocytes of MFD group were also exacerbated by parasitic infection in our NASH model.We highlight that a medium fat diet by itself is able to induce steatohepatitis. Our results also suggest a synergic effect between damage associated with molecular patterns generated during NASH and parasitic infection

  13. Targeted screening strategies to detect Trypanosoma cruzi infection in children.

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    Michael Z Levy

    2007-12-01

    Full Text Available Millions of people are infected with Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Anti-trypanosomal drug therapy can cure infected individuals, but treatment efficacy is highest early in infection. Vector control campaigns disrupt transmission of T. cruzi, but without timely diagnosis, children infected prior to vector control often miss the window of opportunity for effective chemotherapy.We performed a serological survey in children 2-18 years old living in a peri-urban community of Arequipa, Peru, and linked the results to entomologic, spatial and census data gathered during a vector control campaign. 23 of 433 (5.3% [95% CI 3.4-7.9] children were confirmed seropositive for T. cruzi infection by two methods. Spatial analysis revealed that households with infected children were very tightly clustered within looser clusters of households with parasite-infected vectors. Bayesian hierarchical mixed models, which controlled for clustering of infection, showed that a child's risk of being seropositive increased by 20% per year of age and 4% per vector captured within the child's house. Receiver operator characteristic (ROC plots of best-fit models suggest that more than 83% of infected children could be identified while testing only 22% of eligible children.We found evidence of spatially-focal vector-borne T. cruzi transmission in peri-urban Arequipa. Ongoing vector control campaigns, in addition to preventing further parasite transmission, facilitate the collection of data essential to identifying children at high risk of T. cruzi infection. Targeted screening strategies could make integration of diagnosis and treatment of children into Chagas disease control programs feasible in lower-resource settings.

  14. 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.

  15. Patients with Central Lines - What You Need to Know to Avoid a Bloodstream Infection PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    This 60 second PSA is based on the March, 2011 CDC Vital Signs report which indicates bloodstream infections in patients with central lines are largely preventable when healthcare providers use CDC-recommended infection control steps.

  16. Catheter Removal versus Retention in the Management of Catheter-Associated Enterococcal Bloodstream Infections

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    Jonas Marschall

    2013-01-01

    Full Text Available BACKGROUND: Enterococci are an important cause of central venous catheter (CVC-associated bloodstream infections (CA-BSI. It is unclear whether CVC removal is necessary to successfully manage enterococcal CA-BSI.

  17. Comportamento das cepas Y e Peruana do Trypanosoma cruzi no camundongo, após passagem em diferentes meios Behavior of the Y and Peruvian strains of Trypanasoma cruzi in mice, ofter passage through different media

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    Juracy B. Magalhães

    1985-03-01

    Full Text Available Com o objetivo de verificar se o comportamento morfobiológico e histopalógico de cerpa do Trypanosoma cruzi é mantido após modificações no seu meio de manutenção e multiplicação, foram estudados oito grupos de infecção experimental em camundongos com as cepas Y e Peruana, após manutenção nas seguintes condições cultura acelular em meio de Warren, criopreservação em Nitrogênio líquido durante trinta dias, passagem em triatomíneos e passagem em camundongos. Os parâmetros avaliados foram: parasitemia, mortalidade, sobrevida, morfologiaq dos parasitos no sangue periférico, tropismo tíssular e lesões histopatológicoas. Tanto com a cepa Y como Peruana, cada grupo experimental foi dividido em dois subgrupos de acordo com a dose de inóculo, sendo um inoculado com 10.000 e outro com 50.000 formas tripomastigotas, menos o inoculado com formas de triatomíneos em que o inóculo foi apenas com 10.000 tripomastigotas. Observou-se na infecção pela cepa Y, retardo na evolução da parasitemia nos inoculados com formas de cultura e atenuação de virulência com o inóculo de 10.000 formas. Os caracteres básicos da cepa foram mantidos com predominância de macrofagotropismo na fase inicial da infecção e miotropismo nas fases tardias,predominância de forma delgadas e elevada patogenicidade, com 100% de mortalidade embora com variação nos periodos de sobrevida. Na infecção pela cepa Peruana observou-se também retardo da evolução da parasitemia com o inóculo de 10.000 formas provenientes de triatomíneos, de cultura e de criopreservação. Entretanto, as características morfológicas, o tropismo tissular e a patogenicidade foram mantidos.The behavior of two strains of Trypanosoma cruzi (Y and Peruvian strains in experimental mouse infection, after being passed through different conditions of maintainance and cultivation was studied. The conditions were: Warren's acellular culture medium, cryopreservation in liquid

  18. Impact of removing mucosal barrier injury laboratory-confirmed bloodstream infections from central line-associated bloodstream infection rates in the National Healthcare Safety Network, 2014.

    Science.gov (United States)

    See, Isaac; Soe, Minn M; Epstein, Lauren; Edwards, Jonathan R; Magill, Shelley S; Thompson, Nicola D

    2017-03-01

    Central line-associated bloodstream infection (CLABSI) event data reported to the National Healthcare Safety Network from 2014, the first year of required use of the mucosal barrier injury laboratory-confirmed bloodstream infection (MBI-LCBI) definition, were analyzed to assess the impact of removing MBI-LCBI events from CLABSI rates. CLABSI rates decreased significantly in some location types after removing MBI-LCBI events, and MBI-LCBI events will be removed from publicly reported CLABSI rates. Published by Elsevier Inc.

  19. Astrocyte Apoptosis and HIV Replication Are Modulated in Host Cells Coinfected with Trypanosoma cruzi

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    Javier M. Urquiza

    2017-08-01

    Full Text Available The protozoan Trypanosoma cruzi is the etiological agent of Chagas disease. In immunosuppressed individuals, as it occurs in the coinfection with human immunodeficiency virus (HIV, the central nervous system may be affected. In this regard, reactivation of Chagas disease is severe and often lethal, and it accounts for meningoencephalitis. Astrocytes play a crucial role in the environment maintenance of healthy neurons; however, they can host HIV and T. cruzi. In this report, human astrocytes were infected in vitro with both genetically modified-pathogens to express alternative fluorophore. As evidenced by fluorescence microscopy and flow cytometry, HIV and T. cruzi coexist in the same astrocyte, likely favoring reciprocal interactions. In this context, lower rates of cell death were observed in both T. cruzi monoinfected-astrocytes and HIV-T. cruzi coinfection in comparison with those infected only with HIV. The level of HIV replication is significantly diminished under T. cruzi coinfection, but without affecting the infectivity of the HIV progeny. This interference with viral replication appears to be related to the T. cruzi multiplication rate or its increased intracellular presence but does not require their intracellular cohabitation or infected cell-to-cell contact. Among several Th1/Th2/Th17 profile-related cytokines, only IL-6 was overexpressed in HIV-T. cruzi coinfection exhibiting its cytoprotective role. This study demonstrates that T. cruzi and HIV are able to coinfect astrocytes thus altering viral replication and apoptosis.

  20. Recent advances in the microbiological diagnosis of bloodstream infections.

    Science.gov (United States)

    Florio, Walter; Morici, Paola; Ghelardi, Emilia; Barnini, Simona; Lupetti, Antonella

    2018-05-01

    Rapid identification (ID) and antimicrobial susceptibility testing (AST) of the causative agent(s) of bloodstream infections (BSIs) are essential for the prompt administration of an effective antimicrobial therapy, which can result in clinical and financial benefits. Immediately after blood sampling, empirical antimicrobial therapy, chosen on clinical and epidemiological data, is administered. When ID and AST results are available, the clinician decides whether to continue or streamline the antimicrobial therapy, based on the results of the in vitro antimicrobial susceptibility profile of the pathogen. The aim of the present study is to review and discuss the experimental data, advantages, and drawbacks of recently developed technological advances of culture-based and molecular methods for the diagnosis of BSI (including mass spectrometry, magnetic resonance, PCR-based methods, direct inoculation methods, and peptide nucleic acid fluorescence in situ hybridization), the understanding of which could provide new perspectives to improve and fasten the diagnosis and treatment of septic patients. Although blood culture remains the gold standard to diagnose BSIs, newly developed methods can significantly shorten the turnaround time of reliable microbial ID and AST, thus substantially improving the diagnostic yield.

  1. Bloodstream Infections in a Neonatal Intensive Care Unit

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    Mehmet Sah Ižpek

    2016-09-01

    Full Text Available Aim: To determine the pattern of bloodstream infections (BSIs and antimicrobial susceptibility of pathogens in a neonatal intensive care unit (NICU.Material and Method: Positive hemoculture of neonates diagnosed with nosocomial sepsis from March 2011 to March 2014 in the NICU of Diyarbakir Maternity and Children%u2019s Hospital, in the southeastern region of Anatolia, Turkey, were retrospectively reviewed. Results: A total of 148 pathogens were isolated in 142 neonates. The most common microorganisms isolated were Klebsiella pneumoniae (40.5% and Acinetobacter baumannii (29.7% which was a result of a hospital outbreak. Multi-drug resistant (MDR strains accounted for 20.0% of K. pneumoniae isolates and 93.2% of A. baumannii isolates. The sepsis-attributable mortality rate was higher in cases infected with MDR strains than in cases infected without MDR strains or Candida spp (24% vs. 9.7%, p=0.032. Discussion: In our unit, BSIs were more often caused by Gram negative bacteria. BSIs caused by MDR strains were associated with a higher rate of sepsis-attributable mortality.

  2. Epidemiology, surveillance, and prevention of bloodstream infections in hemodialysis patients.

    Science.gov (United States)

    Patel, Priti R; Kallen, Alexander J; Arduino, Matthew J

    2010-09-01

    Infections cause significant morbidity and mortality in patients undergoing hemodialysis. Bloodstream infections (BSIs) are particularly problematic, accounting for a substantial number of hospitalizations in these patients. Hospitalizations for BSI and other vascular access infections appear to have increased dramatically in hemodialysis patients since 1993. These infections frequently are related to central venous catheter (CVC) use for dialysis access. Regional initiatives that have shown successful decreases in catheter-related BSIs in hospitalized patients have generated interest in replicating this success in outpatient hemodialysis populations. Several interventions have been effective in preventing BSIs in the hemodialysis setting. Avoiding the use of CVCs in favor of access types with lower associated BSI risk is among the most important. When CVCs are used, adherence to evidence-based catheter insertion and maintenance practices can positively influence BSI rates. In addition, facility-level surveillance to detect BSIs and stimulate examination of vascular access use and care practices is essential to a comprehensive approach to prevention. This article describes the current epidemiology of BSIs in hemodialysis patients and effective prevention strategies to decrease the incidence of these devastating infections.

  3. A refratariedade das aves ao "Trypanosoma (Schizotrypanum cruzi" II - refratariedade das galinhas desde o nascimento; persistência da refratariedade após Bursectomia; infecções em ovos embrionados The refractory state of birds toward the Trypanosoma (Schizotrypanum cruzi: II - the refractory state begins at hatching and persists after bursectomy, Infections of embryonnated eggs

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    F. Nery-Guimarães

    1972-01-01

    Full Text Available "A refratariedade das galinhas ao T. (S. cruzi, ocorre desde o nascimento e não é eliminada pela bursectomia hormonal. Noventa e oito pintos de 1 a 15 dias de vida (normais ou tratados com testosterona inoculados com o T. (S. cruzi foram negativos. Deste modo, dificilmente a refratariedade poderia ser interpretada como decorrência de um "anticorpo natural", uma vez que a bursectomia provoca uma queda na produção de anticorpos e das gamaglobulinas. Em cerca de 50% de ovos embrionados (normais ou tratados com o hormônio foram vistos flagelados do 4º ao 12º dia de inoculação, observando-se ninhos de amastigotos em alguns embriões. Os pintos nascidos dos mesmos grupos dos ovos examinados e positivos, foram sistematicamente negativos pelo exame do sangue. Um deles sacrificado horas depois de nascido, mostrou amastigotos no coração, mas esses parasitos pareciam degenerados. Provavelmente, se alguns chegam a evoluir para tripomastigotos, estes são destruídos á medida que as células hospedeiras se rompem, e assim jamais são encontrados no sangue circulante.It has already been shown that the refractory state of chickens toward "T. (S. cruzi" appears early at time of hatch. Fifty-four normal newly hatched and inoculated chicks were negative. it has also been verified that this refractory state persists even after hormonal bursectomy (eggs being injected with 2.5 mg of testosterone. Forty-four bursectomized and inoculated newly hatched chicks were negative. If we consider the fact that bursectomy causes a deficiency in the production of antibodies and gammaglobulins, the refractory state seems not to occur on account of a "natural antibody". Inoculations of "T. (S. cruzi" made in 153 eggs (normal or treated with testosterone produced infections of variable intensity in about 50% of them. Although chicks newly hatched from the same groups were always negative. As we have some embryos to be positive until the 21st day of incubation it seems

  4. Refratariedade das galinhas ao "Trypanosoma (Schizotrypanum Cruzi" III - dissociação dos fenômenos da refratariedade e da lise dos epimastigotas pelo soro das aves The refractory state of birds towards the "Trypanosoma (Schizotrypanum cruzi". III - The dissociation of the phenomena of the refractory state and the lysis of the epimastigotes by chicken sera

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    F. Nery-Guimarães

    1974-01-01

    Full Text Available Há muito tempo é sabido serem as aves refratárias ao "T. (S. cruzi". Em trabalhos anteriores verificou-se que nas galinhas pode-se obter infecções "in ovo" diagnosticáveis até o 21º de incubação, porém, logo após o nascimento os pintos mostram-se refratários ao parasito, que é destruído no ponto de inoculação. Neste trabalho verificou-se que tripomastigotas injetados diretamente no sangue, podem ser esporadicamente encontrados até 1h depois. Verificou-se também que galinhas bursectomizadas, com associação de testosterona "in ovo" e ciclofosfamida nos 4 primeiros dias de vida permanecem refratárias. Entretanto, o soro dessas aves perde a capacidade lítica que o soro das aves normais possui para os epimastigotas do "T. (S. cruzi", pela qual são responsáveis as gama-globulinas séricas, conforme foi verificado após o fracionamento do soro em coluna de DEAE-Sefádex A50. A dissociação dos 2 fenômenos, mostra que a capacidade lítica pode ser atribuída a um "anticorpo natural" - uma vez que é eliminada ou grandemente diminuída com a supressão do sistema imunitário bursa- dependente - porém, o mesmo não se pode concluir quanto à refratariedade. Esta, provavelmente, deve estar relacionada ao próprio metabolismo celular após o nascimento.The refractory state of birds to the "T (S cruzi" is well known since long ago. In previous papers it was possible to observe in chicks, infection "in ovo", still present at the last dat of incubation. Nevertheless after hatching the chicks become refractory to the parasite. The destruction of the parasites takes place in the skin at the inoculation point. Throughout these studies the authors verified that the trypomastigotes forms disappear within an hour, after being injected directly into the blood stream. Bursectomized chicks by treatment with testosterone "in ovo" plus cyclophosphamide in the first four days of life, show also the refractory condition, but their sera lack the

  5. Simultaneous identification of Trypanosoma cruzi surface and internal antigens reactive to different immunoglobulin classes (radio-immunoblotting Identificação simultânea de antígenos internos e de superfície de Trypanosoma cruzi reativos para diferentes classes de imunoglobulinas (radio-immunoblotting

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    Anna Maria Simonsen Stolf

    1990-10-01

    Full Text Available A radioactive Western-blotting technique was developed by which the reactivity of Immunoglobulins (Igs from different classes to both membrane radiolabelled and internal parasite antigens is simultaneously identified. The method includes radioiodination of parasites, polypeptide fractionation by SDS-PAGE, Western-blot transfer and autoradiography of the immunoblots developed with anti-Igs conjugates labelled with enzymes. The analysis is then performed by the comparison of common bands on the autoradiograms and the respective substrate stained nitrocellulose blots. This technique was used to analyse T. cruzi trypomastigote surface labelled antigens reactive to IgM, IgA and IgG specific antibodies. A different pattern of reactivity with acute Chagas' disease patients sera was thus obtained.Classes e subclasses de anticorpos apresentam diferentes funções, influenciando a resposta imune humoral de um hospedeiro, frente a um agente infeccioso. Na maioria dos sistemas, o alvo principal é representado pelos antígenos de membrana do parasita. Entretanto, a identificação de antígenos de superfície de parasitas, reativos para classe (e subclasse de imunoglobulinas que não se ligam a proteína-A implica em imunoprecipitações sucessivas, que levam a perda de antígenos e/ou reações inespecíficas. Visando esse estudo, foi desenvolvida uma técnica denominada "radio-immunoblotting", através da qual a reatividade de imunoglobulinas de diferentes classes para antígenos de membrana (e/ou internos foi analisada simultaneamente. O método constitui na marcação prévia da superfície dos parasitas por radioiodação, fracionamento dos polipeptídeos por SDS/PA-GE, transferência das frações para nitrocelulose, reação com soros e conjugados anti-Igs - peroxidase e autoradiografia dos mesmos, a análise é feita comparando-se os antígenos comuns evidenciados na autoradiografia e nas tiras de nitrocelulose coradas com o substrato da peroxidase

  6. The resting electrocardiogram of t. cruzi-infected rats

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    Reinaldo B. Bestetti

    1987-08-01

    Full Text Available A total of 125 rats were infected with the Colômbia strain of T. cruzi (2000 parasites/g shortly after weaning. Of these, 58 survived the acute phase and were used in the present experiment. Twenty eight similar but not infected rats served as controls. All rats were submitted to the resting ECG When they were 6 months old. Classic and 3 precordial leads were employed in order to record the ECG as completely as possible. Electrocardiographic changes similar to those found in human chronic Chagas' heart disease and not previously described in this model were found in 44% of the T. cruzi-infected rats: left axis deviation (22%, right axis deviation (7%, lengthened and bizarre QRS complex (14% and abnormal J point elevation (3%. On the basis of these results, we believe that the resting ECG constitutes a valuable tool for studying experimental chronic Chagas' heart disease in rats.

  7. Molecular characterization and interactome analysis of Trypanosoma cruzi tryparedoxin II.

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    Arias, Diego G; Piñeyro, María Dolores; Iglesias, Alberto A; Guerrero, Sergio A; Robello, Carlos

    2015-04-29

    Trypanosoma cruzi, the causative agent of Chagas disease, possesses two tryparedoxins (TcTXNI and TcTXNII), belonging to the thioredoxin superfamily. TXNs are oxidoreductases which mediate electron transfer between trypanothione and peroxiredoxins. This constitutes a difference with the host cells, in which these activities are mediated by thioredoxins. These differences make TXNs an attractive target for drug development. In a previous work we characterized TcTXNI, including the redox interactome. In this work we extend the study to TcTXNII. We demonstrate that TcTXNII is a transmembrane protein anchored to the surface of the mitochondria and endoplasmic reticulum, with a cytoplasmatic orientation of the redox domain. It would be expressed during the metacyclogenesis process. In order to continue with the characterization of the redox interactome of T. cruzi, we designed an active site mutant TcTXNII lacking the resolving cysteine, and through the expression of this mutant protein and incubation with T. cruzi proteins, heterodisulfide complexes were isolated by affinity chromatography and identified by mass spectrometry. This allowed us to identify sixteen TcTXNII interacting proteins, which are involved in a wide range of cellular processes, indicating the relevance of TcTXNII, and contributing to our understanding of the redox interactome of T. cruzi. T. cruzi, the causative agent of Chagas disease, constitutes a major sanitary problem in Latin America. The number of estimated infected persons is ca. 8 million, 28 million people are at risk of infection and ~20,000 deaths occur per year in endemic regions. No vaccines are available at present, and most drugs currently in use were developed decades ago and show variable efficacy with undesirable side effects. The parasite is able to live and prolipherate inside macrophage phagosomes, where it is exposed to cytotoxic reactive oxygen and nitrogen species, derived from macrophage activation. Therefore, T. cruzi

  8. 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.

  9. Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

    Science.gov (United States)

    Silva-Neto, Mário A. C.; Carneiro, Alan B.; Silva-Cardoso, Livia; Atella, Georgia C.

    2012-01-01

    Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease. PMID:22132309

  10. 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.

  11. 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.

  12. Supervivencia de Trypanosoma cruzi en bebidas experimentalmente contaminadas

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    Diana Carolina Suárez

    2012-03-01

    Conclusiones. La cepa DS de T. cruzi sobrevivió en todas las bebidas por más de 24 horas después de la contaminación y se observó un tiempo de supervivencia de 384 horas a temperatura de refrigeración en el jugo de guanábana.   DOI: http://dx.doi.org/10.7705/biomedica.v32i1.371

  13. Vector-borne transmission of Trypanosoma cruzi among captive Neotropical primates in a Brazilian zoo.

    Science.gov (United States)

    Minuzzi-Souza, Thaís Tâmara Castro; Nitz, Nadjar; Knox, Monique Britto; Reis, Filipe; Hagström, Luciana; Cuba, César A Cuba; Hecht, Mariana Machado; Gurgel-Gonçalves, Rodrigo

    2016-01-26

    Neotropical primates are important sylvatic hosts of Trypanosoma cruzi, the etiological agent of Chagas disease. Infection is often subclinical, but severe disease has been described in both free-ranging and captive primates. Panstrongylus megistus, a major T. cruzi vector, was found infesting a small-primate unit at Brasília zoo (ZooB), Brazil. ZooB lies close to a gallery-forest patch where T. cruzi circulates naturally. Here, we combine parasitological and molecular methods to investigate a focus of T. cruzi infection involving triatomine bugs and Neotropical primates at a zoo located in the Brazilian Savannah. We assessed T. cruzi infection in vectors using optical microscopy (n = 34) and nested PCR (n = 50). We used quantitative PCR (qPCR) to examine blood samples from 26 primates and necropsy samples from two primates that died during the study. We determined parasite lineages in five vectors and two primates by comparing glucose-6-phosphate isomerase (G6pi) gene sequences. Trypanosoma cruzi was found in 44 vectors and 17 primates (six genera and eight species); one Mico chrysoleucus and one Saguinus niger had high parasitaemias. Trypanosoma cruzi DNA was detected in three primates born to qPCR-negative mothers at ZooB and in the two dead specimens. One Callithrix geoffroyi became qPCR-positive over a two-year follow-up. All G6pi sequences matched T. cruzi lineage TcI. Our findings strongly suggest vector-borne T. cruzi transmission within a small-primate unit at ZooB - with vectors, and perhaps also parasites, presumably coming from nearby gallery forest. Periodic checks for vectors and parasites would help eliminate T. cruzi transmission foci in captive-animal facilities. This should be of special importance for captive-breeding programs involving endangered mammals, and would reduce the risk of accidental T. cruzi transmission to keepers and veterinarians.

  14. Trypanosoma cruzi strain TcIV infects raccoons from Illinois

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    Cailey Vandermark

    Full Text Available BACKGROUND The northern limits of Trypanosoma cruzi across the territory of the United States remain unknown. The known vectors Triatoma sanguisuga and T. lecticularia find their northernmost limits in Illinois; yet, earlier screenings of those insects did not reveal the presence of the pathogen, which has not been reported in vectors or reservoir hosts in this state. OBJECTIVES Five species of medium-sized mammals were screened for the presence of T. cruzi. METHODS Genomic DNA was isolated from heart, spleen and skeletal muscle of bobcats (Lynx rufus, n = 60, raccoons (Procyon lotor, n = 37, nine-banded armadillos (Dasypus novemcinctus, n = 5, Virginia opossums (Didelphis virginiana, n = 3, and a red fox (Vulpes vulpes. Infections were detected targeting DNA from the kinetoplast DNA minicircle (kDNA and satellite DNA (satDNA. The discrete typing unit (DTU was determined by amplifying two gene regions: the Spliced Leader Intergenic Region (SL, via a multiplex polymerase chain reaction, and the 24Sα ribosomal DNA via a heminested reaction. Resulting sequences were used to calculate their genetic distance against reference DTUs. FINDINGS 18.9% of raccoons were positive for strain TcIV; the rest of mammals tested negative. MAIN CONCLUSIONS These results confirm for the first time the presence of T. cruzi in wildlife from Illinois, suggesting that a sylvatic life cycle is likely to occur in the region. The analyses of sequences of SL suggest that amplicons resulting from a commonly used multiplex reaction may yield non-homologous fragments.

  15. Heterogeneous infectiousness in guinea pigs experimentally infected with Trypanosoma cruzi.

    Science.gov (United States)

    Castillo-Neyra, Ricardo; Borrini Mayorí, Katty; Salazar Sánchez, Renzo; Ancca Suarez, Jenny; Xie, Sherrie; Náquira Velarde, Cesar; Levy, Michael Z

    2016-02-01

    Guinea pigs are important reservoirs of Trypanosoma cruzi, the causative parasite of Chagas disease, and in the Southern Cone of South America, transmission is mediated mainly by the vector Triatoma infestans. Interestingly, colonies of Triatoma infestans captured from guinea pig corrals sporadically have infection prevalence rates above 80%. Such high values are not consistent with the relatively short 7-8 week parasitemic period that has been reported for guinea pigs in the literature. We experimentally measured the infectious periods of a group of T. cruzi-infected guinea pigs by performing xenodiagnosis and direct microscopy each week for one year. Another group of infected guinea pigs received only direct microscopy to control for the effect that inoculation by triatomine saliva may have on parasitemia in the host. We observed infectious periods longer than those previously reported in a number of guinea pigs from both the xenodiagnosis and control groups. While some guinea pigs were infectious for a short time, other "super-shedders" were parasitemic up to 22 weeks after infection, and/or positive by xenodiagnosis for a year after infection. This heterogeneity in infectiousness has strong implications for T. cruzi transmission dynamics and control, as super-shedder guinea pigs may play a disproportionate role in pathogen spread. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  16. [Esophageal motor disorders in asymptomatic subjects with Trypanosoma cruzi infection].

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    Torres-Aguilera, M; Remes-Troche, J M; Roesch-Dietlen, F; Vázquez-Jiménez, J G; De la Cruz-Patiño, E; Grube-Pagola, P; Ruiz-Juárez, I

    2011-01-01

    The indeterminate chronic or "asymptomatic" phase of Trypanosoma cruzi (Chagas' disease) infection is characterized by the absence of gastrointestinal symptoms, and has an estimated duration of 20 to 30 years. However, the intramural denervation that induces dysfunction of the gastrointestinal tract is progressive. Recently, epidemiological studies have shown that the seroprevalence for this infection in our area ranges between 2% and 3% of the population. To detect the presence of esophageal motor disorders in asymptomatic individuals chronically infected with Trypanosoma cruzi using standard esophageal manometry. A cross sectional study in 28 asymptomatic subjects (27 men, age 40.39 ± 10.79) with serological evidence of infection with Trypanosoma cruzi was performed. In all cases demographic characteristics, gastrointestinal symptoms and esophageal motility disorders using conventional manometry were analyzed. In this study 54% (n = 15) of asymptomatic subjects had an esophageal motor disorder: 5 (18%) had nutcracker esophagus, 5 (18%) nonspecific esophageal motor disorders, 3 (11%) hypertensive lower esophageal sphincter (LES), 1 (4%) an incomplete relaxation of the LES and 1 (4%) had chagasic achalasia. More than half of patients that course with Chagas' disease in the indeterminate phase and that are apparently asymptomatic have impaired esophageal motility. Presence of hypertensive LES raises the possibility that this alteration represents an early stage in the development of chagasic achalasia.

  17. Geographical Distribution of Trypanosoma cruzi Genotypes in Venezuela

    Science.gov (United States)

    Carrasco, Hernán J.; Segovia, Maikell; Llewellyn, Martin S.; Morocoima, Antonio; Urdaneta-Morales, Servio; Martínez, Cinda; Martínez, Clara E.; Garcia, Carlos; Rodríguez, Marlenes; Espinosa, Raul; de Noya, Belkisyolé A.; Díaz-Bello, Zoraida; Herrera, Leidi; Fitzpatrick, Sinead; Yeo, Matthew; Miles, Michael A.; Feliciangeli, M. Dora

    2012-01-01

    Chagas disease is an endemic zoonosis native to the Americas and is caused by the kinetoplastid protozoan parasite Trypanosoma cruzi. The parasite is also highly genetically diverse, with six discrete typing units (DTUs) reported TcI – TcVI. These DTUs broadly correlate with several epidemiogical, ecological and pathological features of Chagas disease. In this manuscript we report the most comprehensive evaluation to date of the genetic diversity of T. cruzi in Venezuela. The dataset includes 778 samples collected and genotyped over the last twelve years from multiple hosts and vectors, including nine wild and domestic mammalian host species, and seven species of triatomine bug, as well as from human sources. Most isolates (732) can be assigned to the TcI clade (94.1%); 24 to the TcIV group (3.1%) and 22 to TcIII (2.8%). Importantly, among the 95 isolates genotyped from human disease cases, 79% belonged to TcI - a DTU common in the Americas, however, 21% belonged to TcIV- a little known genotype previously thought to be rare in humans. Furthermore, were able to assign multiple oral Chagas diseases cases to TcI in the area around the capital, Caracas. We discuss our findings in the context of T. cruzi DTU distributions elsewhere in the Americas, and evaluate the impact they have on the future of Chagas disease control in Venezuela. PMID:22745843

  18. Prevalence of Trypanosoma cruzi/HIV coinfection in southern Brazil

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    Dulce Stauffert

    2017-03-01

    Full Text Available Chagas disease reactivation has been a defining condition for acquired immune deficiency syndrome in Brazil for individuals coinfected with Trypanosoma cruzi and HIV since 2004. Although the first coinfection case was reported in the 1980s, its prevalence has not been firmly established. In order to know coinfection prevalence, a cross-sectional study of 200 HIV patients was performed between January and July 2013 in the city of Pelotas, in southern Rio Grande do Sul, an endemic area for Chagas disease. Ten subjects were found positive for T. cruzi infection by chemiluminescence microparticle immunoassay and indirect immunofluorescence. The survey showed 5% coinfection prevalence among HIV patients (95% CI: 2.0–8.0, which was 3.8 times as high as that estimated by the Ministry of Health of Brazil. Six individuals had a viral load higher than 100,000 copies per μL, a statistically significant difference for T. cruzi presence. These findings highlight the importance of screening HIV patients from Chagas disease endemic areas.

  19. Rhodotorula mucilaginosa Bloodstream Infection in a Case of Duodenal Perforation

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    Rajmane

    2016-08-01

    Full Text Available Introduction Rhodotorula species are widespread in nature and can be isolated from a variety of sources, including air, soil, seawater, plants, and the household environment. They are also widely distributed in hospitals, and their presence could be considered a risk factor for hospitalized patients. These commensal yeasts have emerged as a cause of life-threatening fungemia in patients with depressed immune systems. Case Presentation We report a case of duodenal perforation with peritonitis in a 36-year-old female who was scheduled immediately for exploratory laparotomy followed by closure of perforation and omentopexy. The peritoneal fluid was sent to the microbiology laboratory for routine investigations. On the 4th postoperative day, the patient had a fever that did not subside with antipyretics; hence, blood cultures were sent the next day. The peritoneal fluid and blood culture reports both yielded Rhodotorula mucilaginosa after 3 days of incubation. The patient was started on IV amphotericin B therapy, which resulted in a favorable outcome. Conclusions In humans, Rhodotorula species have been recovered as commensal organisms from the nails, the skin, and the respiratory, gastrointestinal (GI, and urinary tracts. Due to their presence in the GI flora, broad-spectrum antibiotics could contribute to their overgrowth in the GI tract. Localized infections, such as peritonitis, due to Rhodotorula species following infected peritoneal dialysis catheters have been reported in the literature. However, in our case, it seems possible that the fungus might have entered the bloodstream through disruption of the GI mucosa, and to prove this, further study is mandatory. It should also be noted that both amphotericin B and flucytosine have good activity against Rhodotorula in vitro, whereas fluconazole is inactive.

  20. Pediatric bloodstream infections in Cambodia, 2007 to 2011.

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    Stoesser, Nicole; Moore, Catrin E; Pocock, Joanna M; An, Khun Peng; Emary, Kate; Carter, Michael; Sona, Soeng; Poda, Sar; Day, Nicholas; Kumar, Varun; Parry, Christopher M

    2013-07-01

    Pediatric bacterial bloodstream infections (BSIs) are a major cause of morbidity and mortality worldwide. Epidemiological data from resource-limited settings in southeast Asia, such as Cambodia, are sparse but have important implications for treatment and public health strategies. We retrospectively investigated BSI in children at a pediatric hospital and its satellite clinic in Siem Reap, Cambodia, from January 1, 2007, to July 31, 2011. The range of bacterial pathogens and their antimicrobial susceptibility patterns were analyzed in conjunction with demographic, clinical and outcome data. Of 7682 blood cultures with results (99.9% of cultures taken), 606 (7.9%) episodes of BSI were identified in 588 children. The incidence of BSI increased from 14 to 50/1000 admissions (P < 0.001); this was associated with an increased sampling rate. Most BSI were community acquired (89.1%). Common pathogens included Salmonella Typhi (22.8% of all isolates), Staphylococcus aureus (12.2%), Streptococcus pneumoniae (10.0%), Klebsiella pneumoniae (6.4%) and Escherichia coli (6.3%). 21.5% of BSI were caused by a diverse group of uncommon organisms, the majority of which were environmental Gram-negative species. No Listeria monocytogenes or Group B streptococcal BSI were identified. Antimicrobial resistance, particularly among the Enterobacteriaceae, was common. Overall mortality was substantial (19.0%), higher in neonates (36.9%) and independently associated with meningitis/meningoencephalitis and K. pneumoniae infection. BSI is a common problem in Cambodian children attending hospital and associated with significant mortality. Further studies are needed to clarify the epidemiology of neonatal sepsis, the contribution of atypical organisms and the epidemiology of pneumococcal disease before the introduction of vaccine.

  1. Diverse inhibitor chemotypes targeting Trypanosoma cruzi CYP51.

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    Shamila S Gunatilleke

    Full Text Available 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.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.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 CYP51 by sequence or structure. Lead compounds developed by pharmaceutical

  2. Trypanin, a component of the flagellar Dynein regulatory complex, is essential in bloodstream form African trypanosomes.

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    Katherine S Ralston

    2006-09-01

    Full Text Available The Trypanosoma brucei flagellum is a multifunctional organelle with critical roles in motility, cellular morphogenesis, and cell division. Although motility is thought to be important throughout the trypanosome lifecycle, most studies of flagellum structure and function have been restricted to the procyclic lifecycle stage, and our knowledge of the bloodstream form flagellum is limited. We have previously shown that trypanin functions as part of a flagellar dynein regulatory system that transmits regulatory signals from the central pair apparatus and radial spokes to axonemal dyneins. Here we investigate the requirement for this dynein regulatory system in bloodstream form trypanosomes. We demonstrate that trypanin is localized to the flagellum of bloodstream form trypanosomes, in a pattern identical to that seen in procyclic cells. Surprisingly, trypanin RNA interference is lethal in the bloodstream form. These knockdown mutants fail to initiate cytokinesis, but undergo multiple rounds of organelle replication, accumulating multiple flagella, nuclei, kinetoplasts, mitochondria, and flagellum attachment zone structures. These findings suggest that normal flagellar beat is essential in bloodstream form trypanosomes and underscore the emerging concept that there is a dichotomy between trypanosome lifecycle stages with respect to factors that contribute to cell division and cell morphogenesis. This is the first time that a defined dynein regulatory complex has been shown to be essential in any organism and implicates the dynein regulatory complex and other enzymatic regulators of flagellar motility as candidate drug targets for the treatment of African sleeping sickness.

  3. 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...

  4. Seroprevalence of Trypanosoma cruzi in blood donors at the National Blood Transfusion Services--Guyana.

    Science.gov (United States)

    Bwititi, P T; Browne, J

    2012-09-01

    Blood transfusion is an important transmission route of Trypanosoma cruzi (T cruzi), a major parasitic infection in Central and South America. The limited treatment options are most effective in acute Chagas' infection. At present, there is no current data on the prevalence of T cruzi in the blood donor population of Guyana. This information is necessary to protect the supply of the blood donation programme. This study sought to determine the prevalence of T cruzi in the blood supply at the National Blood Transfusion Services of Guyana with the hope of providing knowledge to the on-going surveillance for Chagas' disease worldwide and therefore address the risk of its spread by blood transfusion. Two commercialized ELISAs utilizing crude or recombinant T cruzi antigens were used to study 2000 blood samples voluntarily donated for the purpose of altruistic or family replacement donation retrospectively. The results showed that approximately 1 in 286 donations tested positive for antibodies to T cruzi. These results indicate that T cruzi continues to be a risk in Guyana and there is a need to continue screening donated blood. Trypanosoma cruzi is a life-long infection and infected persons may be asymptomatic chronic carriers of the disease. Education, housing improvement, and controlled use of insecticides should be introduced to contain Chagas' disease.

  5. Selection and optimization of hits from a high-throughput phenotypic screen against Trypanosoma cruzi.

    Science.gov (United States)

    Keenan, Martine; Alexander, Paul W; Chaplin, Jason H; Abbott, Michael J; Diao, Hugo; Wang, Zhisen; Best, Wayne M; Perez, Catherine J; Cornwall, Scott M J; Keatley, Sarah K; Thompson, R C Andrew; Charman, Susan A; White, Karen L; Ryan, Eileen; Chen, Gong; Ioset, Jean-Robert; von Geldern, Thomas W; Chatelain, Eric

    2013-10-01

    Inhibitors of Trypanosoma cruzi with novel mechanisms of action are urgently required to diversify the current clinical and preclinical pipelines. Increasing the number and diversity of hits available for assessment at the beginning of the discovery process will help to achieve this aim. We report the evaluation of multiple hits generated from a high-throughput screen to identify inhibitors of T. cruzi and from these studies the discovery of two novel series currently in lead optimization. Lead compounds from these series potently and selectively inhibit growth of T. cruzi in vitro and the most advanced compound is orally active in a subchronic mouse model of T. cruzi infection. High-throughput screening of novel compound collections has an important role to play in diversifying the trypanosomatid drug discovery portfolio. A new T. cruzi inhibitor series with good drug-like properties and promising in vivo efficacy has been identified through this process.

  6. Vector Competence of Lutzomyia cruzi Naturally Demonstrated for Leishmania infantum and Suspected for Leishmania amazonensis.

    Science.gov (United States)

    de Oliveira, Everton Falcão; Oshiro, Elisa Teruya; Fernandes, Wagner Souza; Ferreira, Alda Maria Teixeira; de Oliveira, Alessandra Gutierrez; Galati, Eunice Aparecida Bianchi

    2017-01-11

    Corumbá city is one of the oldest visceral leishmaniasis-endemic foci in the state of Mato Grosso do Sul, Brazil, where the transmission of Leishmania infantum has been attributed to Lutzomyia cruzi Aiming at investigating the parameters of the vectorial capacity of Lu. cruzi for L. infantum, a project was undertaken in this city. Among these parameters, vector competence was investigated and the results obtained are reported herein. Of the 12 hamsters exposed to feed wild-caught female sandflies, two developed infection with L. infantum and surprisingly, one with Leishmania amazonensis In addition, hamsters with L. infantum infection were bitten only by females of Lu. cruzi, whereas the hamster infected with L. amazonensis was bitten by 124 Lu. cruzi females and one of Evandromyia corumbaensis Although there is a strong suspicion regarding the competence of Lu. cruzi in transmitting L. amazonensis naturally, it was not demonstrated. © The American Society of Tropical Medicine and Hygiene.

  7. Congenital Trypanosoma cruzi Transmission in Santa Cruz, Bolivia

    Science.gov (United States)

    Bern, Caryn; Verastegui, Manuela; Gilman, Robert H.; LaFuente, Carlos; Galdos-Cardenas, Gerson; Calderon, Maritza; Pacori, Juan; Abastoflor, Maria del Carmen; Aparicio, Hugo; Brady, Mark F.; Ferrufino, Lisbeth; Angulo, Noelia; Marcus, Sarah; Sterling, Charles; Maguire, James H.

    2017-01-01

    Background We conducted a study of congenital Trypanosoma cruzi infection in Santa Cruz, Bolivia. Our objective was to apply new tools to identify weak points in current screening algorithms, and find ways to improve them. Methods Women presenting for delivery were screened by rapid and conventional serological tests. For infants of infected mothers, blood specimens obtained on days 0, 7, 21, 30, 90, 180, and 270 were concentrated and examined microscopically; serological tests were performed for the day 90, 180, and 270 specimens. Maternal and infant specimens, including umbilical tissue, were tested by polymerase chain reaction (PCR) targeting the kinetoplast minicircle and by quantitative PCR. Results Of 530 women, 154 (29%) were seropositive. Ten infants had congenital T. cruzi infection. Only 4 infants had positive results of microscopy evaluation in the first month, and none had positive cord blood microscopy results. PCR results were positive for 6 (67%) of 9 cord blood and 7 (87.5%) of 8 umbilical tissue specimens. PCR-positive women were more likely to transmit T. cruzi than were seropositive women with negative PCR results (P < .05). Parasite loads determined by quantitative PCR were higher for mothers of infected infants than for seropositive mothers of uninfected infants (P < .01). Despite intensive efforts, only 58% of at-risk infants had a month 9 specimen collected. Conclusions On the basis of the low sensitivity of microscopy in cord blood and high rate of loss to follow-up, we estimate that current screening programs miss one-half of all infected infants. Molecular techniques may improve early detection. PMID:19877966

  8. Is the anti-tumor property of Trypanosoma cruzi infection mediated by its Calreticulin?

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    Galia Andrea Ramírez-Toloza

    2016-07-01

    Full Text Available Eight to 10 million people in 21 endemic countries are infected with Trypanosoma cruzi. However, only 30% of those infected develop symptoms of Chagas’ disease, a chronic, neglected tropical disease worldwide. Similar to other pathogens, T. cruzi has evolved to resist the host immune response. Studies, performed 80 years ago in the Soviet Union, proposed that T. cruzi infects tumor cells with similar capacity to that displayed for target tissues such as cardiac, aortic or digestive. An antagonistic relationship between T. cruzi infection and cancer development was also proposed, but the molecular mechanisms involved have remained largely unknown. Probably, a variety of T. cruzi molecules is involved. This review focuses on how T. cruzi calreticulin (TcCRT, exteriorized from the endoplasmic reticulum, targets the first classical complement component C1 and negatively regulates the Classical Complement activation cascade, promoting parasite infectivity. We propose that this C1-dependent TcCRT-mediated virulence is critical to explain, at least an important part, of the parasite capacity to inhibit tumor development. We will discuss how TcCRT, by directly interacting with venous and arterial endothelial cells, inhibits angiogenesis and tumor growth. Thus, these TcCRT functions not only illustrate T. cruzi interactions with the host immune defensive strategies, but also illustrate a possible co-evolutionary adaptation to privilege a prolonged interaction with its host.

  9. Heme A synthesis and CcO activity are essential for Trypanosoma cruzi infectivity and replication.

    Science.gov (United States)

    Merli, Marcelo L; Cirulli, Brenda A; Menéndez-Bravo, Simón M; Cricco, Julia A

    2017-06-27

    Trypanosoma cruzi , the causative agent of Chagas disease, presents a complex life cycle and adapts its metabolism to nutrients' availability. Although T. cruzi is an aerobic organism, it does not produce heme. This cofactor is acquired from the host and is distributed and inserted into different heme-proteins such as respiratory complexes in the parasite's mitochondrion. It has been proposed that T. cruzi's energy metabolism relies on a branched respiratory chain with a cytochrome c oxidase-type aa 3 (C c O) as the main terminal oxidase. Heme A, the cofactor for all eukaryotic C c O, is synthesized via two sequential enzymatic reactions catalyzed by heme O synthase (HOS) and heme A synthase (HAS). Previously, TcCox10 and TcCox15 ( Trypanosoma cruzi Cox10 and Cox15 proteins) were identified in T. cruzi They presented HOS and HAS activity, respectively, when they were expressed in yeast. Here, we present the first characterization of TcCox15 in T. cruzi , confirming its role as HAS. It was differentially detected in the different T. cruzi stages, being more abundant in the replicative forms. This regulation could reflect the necessity of more heme A synthesis, and therefore more C c O activity at the replicative stages. Overexpression of a non-functional mutant caused a reduction in heme A content. Moreover, our results clearly showed that this hindrance in the heme A synthesis provoked a reduction on C c O activity and, in consequence, an impairment on T. cruzi survival, proliferation and infectivity. This evidence supports that T. cruzi depends on the respiratory chain activity along its life cycle, being C c O an essential terminal oxidase. © 2017 The Author(s); published by Portland Press Limited on behalf of the Biochemical Society.

  10. Trypanosoma cruzi, cancer and the Cold War Trypanosoma cruzi, câncer e a Guerra Fria

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    Nikolai Krementsov

    2009-07-01

    Full Text Available 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.No verão de 1946, a comunidade internacional que desenvolve pesquisas sobre o câncer, inspirou-se no anúncio de que dois cientistas soviéticos, Nina Kliueva e Grigorii Roskin, descobriram propriedades anticancerígenas em cultura extraída do protozoário existente na América Latina, o Trypanosoma cruzi e produziram um preparado que foi denominado com as iniciais KR - em sua homenagem. Grupos de pesquisadores de diversos países buscaram com entusiasmo as promessas dessa nova linha de investigação. A história da ascensão e queda do interesse nas propriedades anticâncer do T. cruzzi em diferentes países sugere que durante a segunda metade do século 20, a Guerra Fria teve um papel importante na definição das agendas de pesquisas sobre o câncer.

  11. Routine Surveillance for Bloodstream Infections in a Pediatric Hematopoietic Stem Cell Transplant Cohort: Do Patients Benefit?

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    Heather Rigby

    2007-01-01

    Full Text Available BACKGROUND: Hematopoietic stem cell transplant (HSCT recipients are at a high risk for late bloodstream infection (BSI. Controversy exists regarding the benefit of surveillance blood cultures in this immunosuppressed population. Despite the common use of this practice, the practical value is not well established in non-neutropenic children following HSCT.

  12. Patients with Central Lines - What You Need to Know to Avoid a Bloodstream Infection PSA (:60)

    Centers for Disease Control (CDC) Podcasts

    2011-03-01

    This 60 second PSA is based on the March, 2011 CDC Vital Signs report which indicates bloodstream infections in patients with central lines are largely preventable when healthcare providers use CDC-recommended infection control steps.  Created: 3/1/2011 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/1/2011.

  13. Emergence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Bloodstream Infections in Denmark

    DEFF Research Database (Denmark)

    Larsen, Jesper; Petersen, Andreas; Larsen, Anders R.

    2017-01-01

    Background: Livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) is causing an increasing number of skin and soft tissue infections (SSTIs) in Denmark and other European countries with industrial pig production. Yet, its impact on MRSA bloodstream...

  14. Blood culture procedures and diagnosis of Malassezia furfur bloodstream infections : Strength and weakness

    NARCIS (Netherlands)

    Iatta, Roberta; Battista, Michela; Miragliotta, Giuseppe; Boekhout, Teun; Otranto, Domenico; Cafarchia, Claudia

    2017-01-01

    The occurrence of Malassezia spp. bloodstream infections (BSIs) in neonatal intensive care unit was evaluated by using pediatric Isolator, BacT/Alert systems and central venous catheter (CVC) culture. The efficacy of BacT/Alert system in detecting Malassezia was assessed by conventional procedures,

  15. Risk factors for laboratory-confirmed bloodstream infection in neonates undergoing surgical procedures

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    Roberta Maia de Castro Romanelli

    2014-07-01

    Conclusions: Shortening time on parenteral nutrition whenever possible and preference for non-invasive ventilation in neonates undergoing surgery should be considered in the assistance of these patients, with the goal of reducing Healthcare Associated Infections, especially laboratory-confirmed bloodstream infection.

  16. Occurrence of yeast bloodstream infections between 1987 and 1995 in five Dutch university hospitals

    NARCIS (Netherlands)

    A. Voss (Andreas); J.A.J.W. Kluytmans (Jan); J.G. Koeleman; L. Spanjaard (Lodewijk); C.M.J.E. Vandenbroucke-Grauls (Christina); H.A. Verbrugh (Henri); M.C. Vos (Margreet); A.Y.L. Weersink (A. Y L); J.A.A. Hoogkamp-Korstanje (J. A A); J.F. Meis

    1996-01-01

    textabstractThe aim of this study was to identify retrospectively trends in fungal bloodstream infections in The Netherlands in the period from 1987 to 1995. Results of over 395,000 blood cultures from five Dutch university hospitals were evaluated. Overall, there were more than 12 million patient

  17. Epidemiological investigation of Candida species causing bloodstream infection in paediatric small bowel transplant recipients.

    Science.gov (United States)

    Suhr, Mallory J; Gomes-Neto, João Carlos; Banjara, Nabaraj; Florescu, Diana F; Mercer, David F; Iwen, Peter C; Hallen-Adams, Heather E

    2017-06-01

    Small bowel transplantation (SBT) can be a life-saving medical procedure. However, these recipients experience high risk of bloodstream infections caused by Candida. This research aims to characterise the SBT recipient gut microbiota over time following transplantation and investigate the epidemiology of candidaemia in seven paediatric patients. Candida species from the recipients' ileum and bloodstream were identified by internal transcribed spacer sequence and distinguished to strain by multilocus sequence typing and randomly amplified polymorphic DNA. Antifungal susceptibility of bloodstream isolates was determined against nine antifungals. Twenty-two ileostomy samples harboured at least one Candida species. Fungaemia were caused by Candida parapsilosis, Candida albicans, Candida glabrata, Candida orthopsilosis and Candida pelliculosa. All but three bloodstream isolates showed susceptibility to all the antifungals tested. One C. glabrata isolate showed multidrug resistance to itraconazole, amphotericin B and posaconazole and intermediate resistance to caspofungin. Results are congruent with both endogenous (C. albicans, C. glabrata) and exogenous (C. parapsilosis) infections; results also suggest two patients were infected by the same strain of C. parapsilosis. Continuing to work towards a better understanding of sources of infection-particularly the exogenous sources-would lead to targeted prevention strategies. © 2017 Blackwell Verlag GmbH.

  18. Non-cytochrome mediated mitochondrial ATP production in bloodstream form Trypanosoma brucei brucei

    NARCIS (Netherlands)

    Bienen, E. J.; Maturi, R. K.; Pollakis, G.; Clarkson, A. B.

    1993-01-01

    The life cycle of Trypanosoma brucei brucei involves a series of differentiation steps characterized by marked changes in mitochondrial development and function. The bloodstream forms of this parasite completely lack cytochromes and have not been considered to have any Krebs cycle function. It has

  19. Drug discovery for Chagas disease should consider Trypanosoma cruzi strain diversity

    Directory of Open Access Journals (Sweden)

    Bianca Zingales

    2014-09-01

    Full Text Available This opinion piece presents an approach to standardisation of an important aspect of Chagas disease drug discovery and development: selecting Trypanosoma cruzi strains for in vitro screening. We discuss the rationale for strain selection representing T. cruzi diversity and provide recommendations on the preferred parasite stage for drug discovery, T. cruzi discrete typing units to include in the panel of strains and the number of strains/clones for primary screens and lead compounds. We also consider experimental approaches for in vitro drug assays. The Figure illustrates the current Chagas disease drug-discovery and development landscape.

  20. Antibody Maturation in Trypanosoma cruzi-Infected Rats

    Science.gov (United States)

    Marcipar, Iván S.; Risso, Marikena G.; Silber, Ariel M.; Revelli, Silvia; Marcipar, Alberto J.

    2001-01-01

    The study of antibody avidity changes during infection has improved the understanding of the pathologic processes involved in several infectious diseases. In some infections, like toxoplasmosis, this information is being used for diagnostic purposes. Results of the evolution of antibody avidity for different specific antigens in Trypanosome cruzi-infected rats are presented. A Western blotting technique, combined with avidity analysis to identify antigens that elicit high-avidity antibodies, is suggested. In this system, antibodies showed high avidity values only during the chronic phase of infection and only in relation to antibodies against 21-, 33-, 41-, 42-, 56-, 58-, 66-, and 72-kDa antigens. Finally, a 97-kDa T. cruzi antigen, which was recognized by high-avidity antibodies and occurred in noninfected rats, was identified. These results allow us to evaluate the different antigens in chagasic infection. Our results show that with the correct choice of antigen it is possible to detect differences in maturation of antibodies and to discriminate, in an experimental model, between recent (acute) and chronic infections. PMID:11427430

  1. Benznidazole induces in vitro anaerobic metabolism in Trypanosoma cruzi epimastigotes

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    Marina Clare Vinaud

    2017-11-01

    Full Text Available Objective: To determine the biochemical alterations of the energetic metabolism of Trypanosoma cruzi epimastigotes in vitro exposed to different concentrations of benzinidazole. Methods: Biochemical analyses were performed at 3, 6 (log phase, 9 and 12 (stationary phase days of culture. Parasites were exposed to five concentrations of benzinidazole. Glycolysis, tricarboxilic acid cycle and fatty acids oxidation pathways were quantified through chromatography. Glucose, urea and creatinine were quantified through spectrophotometric analysis. Results: Anaerobic fermentation and fatty acids oxidation were increased in the stationary phase of the culture. Benzinidazole at high concentrations induced anaerobic metabolism in the log phase of the culture while the parasites exposed to the lower concentrations preferred the citric acid cycle as energy production pathway. Benzinidazole did not influence on the proteins catabolism. Conclusions: It is possible to conclude that there are metabolic differences between evolutive forms of Trypanosoma cruzi and the main drug used for its treatment induces the anaerobic metabolism in the parasite, possibly impairing the mitochondrial pathways.

  2. Lysophosphatidylcholine: A Novel Modulator of Trypanosoma cruzi Transmission

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    Mário A. C. Silva-Neto

    2012-01-01

    Full Text Available Lysophosphatidylcholine is a bioactive lipid that regulates a large number of cellular processes and is especially present during the deposition and infiltration of inflammatory cells and deposition of atheromatous plaque. Such molecule is also present in saliva and feces of the hematophagous organism Rhodnius prolixus, a triatominae bug vector of Chagas disease. We have recently demonstrated that LPC is a modulator of Trypanosoma cruzi transmission. It acts as a powerful chemoattractant for inflammatory cells at the site of the insect bite, which will provide a concentrated population of cells available for parasite infection. Also, LPC increases macrophage intracellular calcium concentrations that ultimately enhance parasite invasion. Finally, LPC inhibits NO production by macrophages stimulated by live T. cruzi, and thus interferes with the immune system of the vertebrate host. In the present paper, we discuss the main signaling mechanisms that are likely used by such molecule and their eventual use as targets to block parasite transmission and the pathogenesis of Chagas disease.

  3. Caracterização biológica, histopatológica e análise de ácido nucléico de uma cepa Trypanosoma cruzi da região de Marília, SP Biological and histopathological characterization together with nucleic acids analysis of a Trypanosoma cruzi strain from Marília, São Paulo State

    Directory of Open Access Journals (Sweden)

    Luciamáre Perinetti Alves Martins

    2003-01-01

    Full Text Available Estudou-se o comportamento biológico e histopatológico de uma cepa genuínamente mariliense de Trypanosoma cruzi, isolada em 1997 através de xenodiagnóstico artificial. Vinte e cinco camundongos swiss foram infectados intraperitonealmente, sendo 11 utilizados para a realização da curva parasitêmica e observação da morfologia dos tripomastigotas e 14 foram sacrificados após o 17, 23, 30, 60 e 180 dias pós-infecção e coletados coração, esôfago, fígado, cólon, e músculo esquelético (fragmento da coxa direita para análise histopatológica. Cultura em meio LIT foi realizada para análise de DNA. Os resultados mostraram predomínio de formas largas, baixa parasitemia com picos médios de 860 tripomastigotas/5mil de sangue ao redor do 20º dia de infecção. Nenhum camundongo morreu na fase aguda da infecção. Exame histopatológico mostrou poucos ninhos de amastigotas em coração, raros em músculo esquelético e cólon com discreto processo inflamatório. Comparada com a cepa Y, que foi isolada de uma paciente da mesma região, notamos diferentes características biológicas e comportamentais, porém a análise de DNA as coloca no mesmo grupo, demonstrando a proximidade dessas cepas.The aim of this report was to study the biological and histopathological behavior of a Trypanosoma cruzi strain, which is found in the region of Marília. The strain was isolated in 1997, by artificial xenodiagnosis. Twenty-five swiss mice were intraperitoneally inoculated. Eleven were used for observation of parasitemia and trypomastigotes morphology and 14 were sacrificed after 17, 23, 30, 60 and 180 days post-infection. Heart, esophagus, liver, colon, and skeletal muscle (fragment of the right thigh were collected for histopathological study. LIT culture medium was accomplished for DNA analysis. The results showed predominance of broad forms, low parasitemia with mean peaks of 860 trypomastigotes/5mul of blood of the 20th day of infection. No

  4. Prevention of bloodstream infections by photodynamic inactivation of multiresistant Pseudomonas aeruginosa in burn wounds

    Science.gov (United States)

    Hashimoto, M. C. E.; Prates, R. A.; Toffoli, D. J.; Courrol, L. C.; Ribeiro, M. S.

    2010-02-01

    Bloodstream infections are potentially life-threatening diseases. They can cause serious secondary infections, and may result in endocarditis, severe sepsis or toxic-shock syndrome. Pseudomonas aeruginosa is an opportunistic pathogen and one of the most important etiological factors responsible for nosocomial infections, mainly in immuno-compromissed hosts, characteristic of patients with severe burns. Its multiresistance to antibiotics produces many therapeutic problems, and for this reason, the development of an alternative method to antibiotic therapy is needed. Photodynamic inactivation (PDI) may be an effective and alternative therapeutic option to prevent bloodstream infections in patients with severe burns. In this study we report the use of PDI to prevent bloodstream infections in mice with third-degree burns. Burns were produced on the back of the animals and they were infected with 109 cfu/mL of multi-resistant (MR) P. aeruginosa. Fifteen animals were divided into 3 groups: control, PDT blue and PDT red. PDT was performed thirty minutes after bacterial inoculation using 10μM HB:La+3 and a light-emitting diode (LED) emitting at λ=460nm+/-20nm and a LED emitting at λ=645 nm+/-10nm for 120s. Blood of mice were colected at 7h, 10h, 15h, 18h and 22h pos-infection (p.i.) for bacterial counting. Control group presented 1×104 cfu/mL in bloodstream at 7h p.i. increasing to 1×106 at 22h, while mice PDT-treated did not present any bacteria at 7h; only at 22h p.i. they presented 1×104cfu/mL. These results suggest that HB:La+3 associated to blue LED or red LED is effective to delay and diminish MR P.aeruginosa bloodstream invasion in third-degree-burned mice.

  5. Bloodstream form pre-adaptation to the tsetse fly inTrypanosoma brucei

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    Eva eRico

    2013-11-01

    Full Text Available African trypanosomes are sustained in the bloodstream of their mammalian hosts by their extreme capacity for antigenic variation. However, for life cycle progression, trypanosomes also must generate transmission stages called stumpy forms that are pre-adapted to survive when taken up during the bloodmeal of the disease vector, tsetse flies. These stumpy forms are rather different to the proliferative slender forms that maintain the bloodstream parasitaemia. Firstly, they are non proliferative and morphologically distinct, secondly, they show particular sensitivity to environmental cues that signal entry to the tsetse fly and, thirdly, they are relatively robust such that they survive the changes in temperature, pH and proteolytic environment encountered within the tsetse midgut. These characteristics require regulated changes in gene expression to pre-adapt the parasite and the use of environmental sensing mechanisms, both of which allow the rapid initiation of differentiation to tsetse midgut procyclic forms upon transmission. Interestingly, the generation of stumpy forms is also regulated and periodic in the mammalian blood, this being governed by a density-sensing mechanism whereby a parasite-derived signal drives cell cycle arrest and cellular development both to optimise transmission and to prevent uncontrolled parasite multiplication overwhelming the host.In this review we detail recent developments in our understanding of the molecular mechanisms that underpin the production of stumpy forms in the mammalian bloodstream and their signal perception pathways both in the mammalian bloodstream and upon entry into the tsetse fly. These discoveries are discussed in the context of conserved eukaryotic signalling and differentiation mechanisms. Further, their potential to act as targets for therapeutic strategies that disrupt parasite development either in the mammalian bloodstream or upon their transmission to tsetse flies is also discussed.

  6. Antimicrobial susceptibility and molecular epidemiology of clinical Enterobacter cloacae bloodstream isolates in Shanghai, China.

    Directory of Open Access Journals (Sweden)

    Su Wang

    Full Text Available Enterobacter cloacae is a major nosocomial pathogen causing bloodstream infections. We retrospectively conducted a study to assess antimicrobial susceptibility and phylogenetic relationships of E. cloacae bloodstream isolates in two tertiary university-affiliated hospitals in Shanghai, in order to facilitate managements of E. cloacae bloodstream infections and highlight some unknowns for future prevention.Fifty-three non-duplicate E. cloacae bloodstream isolates were consecutively collected from 2013 to 2016. Antimicrobial susceptibility was determined by disk diffusion. PCR was performed to detect extended-spectrum β-lactamase (ESBL, carbapenemase and colistin resistance (MCR-1 gene. Plasmid-mediated AmpC β-lactamase (pAmpC genes were detected using a multiplex PCR assay targeting MIR/ACT gene (closely related to chromosomal EBC family gene and other plasmid-mediated genes, including DHA, MOX, CMY, ACC, and FOX. eBURST was applied to analyze multi-locus sequence typing (MLST.The rates of resistance to all tested antibiotics were 0.05. SHV (6/8, 75.0% and MIR/ACT (15/18, 83.3% predominated in ESBL and pAmpC producers respectively. Moreover, 2 isolates co-carried TEM-1, SHV-12, IMP-26 and DHA-1. MLST analysis distinguished the 53 isolates into 51 STs and only ST414 and ST520 were assigned two isolates of each (2/53.The antimicrobial resistance rates were low among 53 E. cloacae bloodstream isolates in the two hospitals. Multiclonality disclosed no evidence on spread of these isolates in Shanghai. The simultaneous presence of ESBL, carbapenemase and pAmpC detected in 2 isolates was firstly reported in Shanghai, which necessitated active ongoing surveillances and consistent prevention and control of E. cloacae.

  7. Nosocomial bloodstream infection in a neonatal intensive care unit of a medical center: a three-year review.

    Science.gov (United States)

    Tseng, Ya-Chun; Chiu, Yu-Chiao; Wang, Jen-Hsien; Lin, Hsiao-Chuan; Lin, Hung-Chih; Su, Bai-Horng; Chiu, Hsiu-Hui

    2002-09-01

    Bloodstream infections are the most frequent nosocomial infections in neonatal intensive care units. This retrospective study surveyed the epidemiologic characteristics of nosocomial bloodstream infections which occurred in the neonatal intensive care unit from January 1, 1997 to December 31, 1999. The overall infection patient rate was 5.5% in the 3-year period, and the overall infection patient-day rate was 4.4 per 1000 patient-days. Low birth weight was a risk factor for bloodstream infections. The rate of infection for neonates with birth weight below 1000 g ranged from 36.6% to 45.8% (1997: 36.6%; 1998: 45.8% and 1999: 38.9%). The most common pathogens causing nosocomial bloodstream infection were: Staphylococcus aureus (18.5%) (with 92% oxacillin-resistant), Acinectobacter baumannii (16.3%), Klebsiella pneumoniae (11.9%), Escherichia coli (9.6%), and Pseudomonas aeruginosa (8.1%). The mortality due to nosocomial bloodstream infection was highest among gram-negative bacteria, especially with P. aeruginosa (45.5%). Therefore, surveillance of nosocomial bloodstream infection and successful strategies to decrease nosocomial bloodstream infection, such as infection control and optimal antibiotic use, are warranted.

  8. [Clinical features of invasive candidiasis and risk factors for Candida bloodstream infection in children: a multicenter study in Urumqi, China].

    Science.gov (United States)

    Ai Er Ken, Ai Bi Bai; Ma, Zhi-Hua; Xiong, Dai-Qin; Xu, Pei-Ru

    2017-04-01

    To investigate the clinical features of invasive candidiasis in children and the risk factors for Candida bloodstream infection. A retrospective study was performed on 134 children with invasive candidiasis and hospitalized in 5 tertiary hospitals in Urumqi, China, between January 2010 and December 2015. The Candida species distribution was investigated. The clinical data were compared between the patients with and without Candida bloodstream infection. The risk factors for Candida bloodstream infection were investigated using multivariate logistic regression analysis. A total of 134 Candida strains were isolated from 134 children with invasive candidiasis, and non-albicans Candida (NAC) accounted for 53.0%. The incidence of invasive candidiasis in the PICU and other pediatric wards were 41.8% and 48.5% respectively. Sixty-eight patients (50.7%) had Candida bloodstream infection, and 45 patients (33.6%) had Candida urinary tract infection. There were significant differences in age, rate of use of broad-spectrum antibiotics, and incidence rates of chronic renal insufficiency, heart failure, urinary catheterization, and NAC infection between the patients with and without Candida bloodstream infection (Pcandidiasis is similar between the PICU and other pediatric wards. NAC is the most common species of invasive candidiasis. Candida bloodstream infection is the most common invasive infection. Younger age (1-24 months) and NAC infection are the risk factors for Candida bloodstream infection.

  9. Cytokine responses to Staphylococcus aureus bloodstream infection differ between patient cohorts that have different clinical courses of infection.

    Science.gov (United States)

    McNicholas, Sinead; Talento, Alida Fe; O'Gorman, Joanne; Hannan, Margaret M; Lynch, Maureen; Greene, Catherine M; Humphreys, Hilary; Fitzgerald-Hughes, Deirdre

    2014-11-15

    The clinical course of Staphylococcus aureus bloodstream infection is unpredictable and bacterial virulence, host immune response and patient characteristics are among the factors that contribute to the clinical course of infection. To investigate the relationship between cytokine response and clinical outcome, circulating cytokine levels were investigated in response to S. aureus bloodstream infection in patients with different clinical courses of infection. A prospective study was carried out in 61 patients with S. aureus bloodstream infection and circulating levels of IL-6, GRO-γ, RANTES and leptin were assessed over the course of the infection. Levels were compared in patients with complicated courses of infection (e.g. infective endocarditis) versus uncomplicated courses of S. aureus bloodstream infection and methicillin-resistant S. aureus Vs methicillin-susceptible S. aureus infection. Significantly lower leptin levels (p < 0.05) and significantly higher IL-6 levels (p < 0.05) were detected at laboratory diagnosis in patients with complicated compared to uncomplicated S. aureus bloodstream infection. Significantly higher levels of GRO-γ were associated with MRSA infection compared to MSSA infection. IL-6 may be an early inflammatory marker of complicated S. aureus bloodstream infection. Leptin may be protective against the development of a complicated S. aureus bloodstream infection.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    CSIR Research Space (South Africa)

    Genovesio, A

    2011-05-01

    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...

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Prevalence of Trypanosoma cruzi and Other Trypanosomatids in Frequently-Hunted Wild Mammals from the Peruvian Amazon.

    Science.gov (United States)

    Morales, E Angelo; Mayor, Pedro; Bowler, Mark; Aysanoa, Esar; Pérez-Velez, Erika S; Pérez, Jocelyn; Ventocilla, Julio A; Baldeviano, G Christian; Lescano, Andrés G

    2017-11-01

    To better understand the ecology of Trypanosoma cruzi in the northeastern Peruvian Amazon, we evaluated the prevalence of T. cruzi and other trypanosomatids in four orders of wild mammals hunted and consumed by inhabitants of three remote indigenous communities in the Peruvian Amazon. Of 300 wild mammals sampled, 115 (38.3%) were infected with trypanosomatids and 15 (5.0%) with T. cruzi. The prevalence of T. cruzi within each species was as follows: large rodents ( Cuniculus paca , 5.5%; Dasyprocta spp., 2.6%), edentates ( Dasypus novemcinctus , 4.2%), and carnivores with higher prevalence ( Nasua nasua , 18.8%). The high prevalence of T. cruzi and other trypanosomatids in frequently hunted wild mammals suggests a sizeable T. cruzi sylvatic reservoir in remote Amazonian locations.

  14. The Prevalence of Trypanosoma cruzi, the Causal Agent of Chagas Disease, in Texas Rodent Populations.

    Science.gov (United States)

    Aleman, Adriana; Guerra, Trina; Maikis, Troy J; Milholland, Matthew T; Castro-Arellano, Ivan; Forstner, Michael R J; Hahn, Dittmar

    2017-03-01

    Rodent species were assessed as potential hosts of Trypanosoma cruzi, the etiologic agent of Chagas disease, from five sites throughout Texas in sylvan and disturbed habitats. A total of 592 rodents were captured, resulting in a wide taxonomic representation of 11 genera and 15 species. Heart samples of 543 individuals were successfully analyzed by SybrGreen-based quantitative PCR (qPCR) targeting a 166 bp fragment of satellite DNA of T. cruzi. Eight rodents representing six species from six genera and two families were infected with T. cruzi. This is the first report of T. cruzi in the pygmy mouse (Baiomys taylori) and the white-footed mouse (Peromyscus leucopus) for the USA. All infected rodents were from the southernmost site (Las Palomas Wildlife Management Area). No differences in pathogen prevalence existed between disturbed habitats (5 of 131 tested; 3.8%) and sylvan habitats (3 of 40 tested; 7.5%). Most positives (n = 6, 16% prevalence) were detected in late winter with single positives in both spring (3% prevalence) and fall (1% prevalence). Additionally, 30 Triatoma insects were collected opportunistically from sites in central Texas. Fifty percent of these insects, i.e., 13 T. gerstaeckeri (68%), and two T. lecticularia (100%) were positive for T. cruzi. Comparative sequence analyses of 18S rRNA of samples provided identical results with respect to detection of the presence or absence of T. cruzi and assigned T. cruzi from rodents collected in late winter to lineage TcI. T. cruzi from Triatoma sp. and rodents from subsequent collections in spring and fall were different, however, and could not be assigned to other lineages with certainty.

  15. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors required during Trypanosoma cruzi parasitophorous vacuole development.

    Science.gov (United States)

    Cueto, Juan Agustín; Vanrell, María Cristina; Salassa, Betiana Nebaí; Nola, Sébastien; Galli, Thierry; Colombo, María Isabel; Romano, Patricia Silvia

    2017-06-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is an obligate intracellular parasite that exploits different host vesicular pathways to invade the target cells. Vesicular and target soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) are key proteins of the intracellular membrane fusion machinery. During the early times of T. cruzi infection, several vesicles are attracted to the parasite contact sites in the plasma membrane. Fusion of these vesicles promotes the formation of the parasitic vacuole and parasite entry. In this work, we study the requirement and the nature of SNAREs involved in the fusion events that take place during T. cruzi infection. Our results show that inhibition of N-ethylmaleimide-sensitive factor protein, a protein required for SNARE complex disassembly, impairs T. cruzi infection. Both TI-VAMP/VAMP7 and cellubrevin/VAMP3, two v-SNAREs of the endocytic and exocytic pathways, are specifically recruited to the parasitophorous vacuole membrane in a synchronized manner but, although VAMP3 is acquired earlier than VAMP7, impairment of VAMP3 by tetanus neurotoxin fails to reduce T. cruzi infection. In contrast, reduction of VAMP7 activity by expression of VAMP7's longin domain, depletion by small interfering RNA or knockout, significantly decreases T. cruzi infection susceptibility as a result of a minor acquisition of lysosomal components to the parasitic vacuole. In addition, overexpression of the VAMP7 partner Vti1b increases the infection, whereas expression of a KIF5 kinesin mutant reduces VAMP7 recruitment to vacuole and, concomitantly, T. cruzi infection. Altogether, these data support a key role of TI-VAMP/VAMP7 in the fusion events that culminate in the T. cruzi parasitophorous vacuole development. © 2016 John Wiley & Sons Ltd.

  16. DNA content analysis allows discrimination between Trypanosoma cruzi and Trypanosoma rangeli.

    Science.gov (United States)

    Naves, Lucila Langoni; da Silva, Marcos Vinícius; Fajardo, Emanuella Francisco; da Silva, Raíssa Bernardes; De Vito, Fernanda Bernadelli; Rodrigues, Virmondes; Lages-Silva, Eliane; Ramírez, Luis Eduardo; Pedrosa, André Luiz

    2017-01-01

    Trypanosoma cruzi, a human protozoan parasite, is the causative agent of Chagas disease. Currently the species is divided into six taxonomic groups. The genome of the CL Brener clone has been estimated to be 106.4-110.7 Mb, and DNA content analyses revealed that it is a diploid hybrid clone. Trypanosoma rangeli is a hemoflagellate that has the same reservoirs and vectors as T. cruzi; however, it is non-pathogenic to vertebrate hosts. The haploid genome of T. rangeli was previously estimated to be 24 Mb. The parasitic strains of T. rangeli are divided into KP1(+) and KP1(-). Thus, the objective of this study was to investigate the DNA content in different strains of T. cruzi and T. rangeli by flow cytometry. All T. cruzi and T. rangeli strains yielded cell cycle profiles with clearly identifiable G1-0 (2n) and G2-M (4n) peaks. T. cruzi and T. rangeli genome sizes were estimated using the clone CL Brener and the Leishmania major CC1 as reference cell lines because their genome sequences have been previously determined. The DNA content of T. cruzi strains ranged from 87,41 to 108,16 Mb, and the DNA content of T. rangeli strains ranged from 63,25 Mb to 68,66 Mb. No differences in DNA content were observed between KP1(+) and KP1(-) T. rangeli strains. Cultures containing mixtures of the epimastigote forms of T. cruzi and T. rangeli strains resulted in cell cycle profiles with distinct G1 peaks for strains of each species. These results demonstrate that DNA content analysis by flow cytometry is a reliable technique for discrimination between T. cruzi and T. rangeli isolated from different hosts.

  17. IgG subclass reactivity to Trypanosoma cruzi in chronic chagasic patients.

    Science.gov (United States)

    Hernández-Becerril, N; Nava, A; Reyes, P A; Monteón, V M

    2001-01-01

    The anti-Trypanosoma cruzi antibodies isotype profile in Chagas' disease has been studied in relation to different clinical manifestations. A high titer of IgG anti-T. cruzi antibodies is found in patients with cardiac involvement, while a high titer of IgA anti-T. cruzi antibodies is associated with digestive forms. The aim of this work was to analyze the IgG subclass reactivity of anti-T. cruzi antibodies in patients with chronic Chagasic cardiomyopathy. Twelve consecutive chagasic patients were analyzed for IgG subclass reactivity to a T. cruzi antigenic extract. They had a complete clinical evaluation, peripheral EKG, echocardiography, left ventriculogram, and coronariography. All patients came from rural areas of Mexico and had lived in endemic zones for over seven years. They presented left ventricular endsystolic dimension above 42 mm in 58% (7/12) and ejection fraction below 50% in 58% (7/12). We found that IgG1 and IgG2 anti-T. cruzi antibodies showed higher titer than IgG3 antibodies, with consistently low titer of IgG4 antibodies. Expression of the four IgG subclasses of anti-T. cruzi antibodies suggest a mixed Th1/Th2-like immune response under a probably continuous chronic antigenic stimulation. On the other hand, high levels of IgG2 anti-T. cruzi antibodies showed a tendency to be associated with severe cardiomegaly. Our results suggest that a mixed Th1/Th2-like immune response may take place in chronic chagasic patients under a chronic antigenic stimulation.

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

    OpenAIRE

    Ruiz-Garcia, Manuel; Montilla, Marleny; Nicholls, Sebastian; Alvarez, Diana

    2001-01-01

    Although Colombia presents an enormous biological diversity, few studies have been conducted on the population genetics of Trypanosoma cruzi. This study was carried out with 23 Colombian stocks of this protozoa analyzed for 13 isoenzymatic loci. The Hardy-Weinberg equilibrium, the genetic diversity and heterogeneity, the genetic relationships and the possible spatial structure of these 23 Colombian stocks of T. cruzi were estimated. The majority of results obtained are in agreement with a clo...

  19. New oxirane derivatives of 1,4-naphthoquinones and their evaluation against T. cruzi epimastigote forms.

    Science.gov (United States)

    Carneiro, Paula F; do Nascimento, Samara B; Pinto, Antonio V; Pinto, Maria do Carmo F R; Lechuga, Guilherme C; Santos, Dilvani O; dos Santos Júnior, Helvécio M; Resende, Jackson A L C; Bourguignon, Saulo C; Ferreira, Vitor F

    2012-08-15

    New oxirane derivatives were synthesized using six naphthoquinones as the starting materials. Our biological results showed that these oxiranes acted as trypanocidal agents against Trypanosoma cruzi with minimal cytotoxicity in the VERO cell line compared to naphthoquinones. In particular, oxirane derivative 14 showed low cytotoxicity in a mammalian cell line and exhibited better activity against epimastigote forms of T.cruzi than the current drug used to treat Chagas disease, benznidazole. Copyright © 2012 Elsevier Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

  1. The Ly49E receptor inhibits the immune control of acute Trypanosoma cruzi infection

    Directory of Open Access Journals (Sweden)

    Jessica Filtjens

    2016-11-01

    Full Text Available The protozoan parasite Trypanosoma cruzi (T. cruzi circulates in the blood upon infection and invades a variety of cells. Parasites intensively multiply during the acute phase of infection and persist lifelong at low levels in tissues and blood during the chronic phase. Natural killer (NK and NKT cells play an important role in the immune control of T. cruzi infection, mainly by releasing the cytokine IFN-γ that activates the microbicidal action of macrophages and other cells and shapes a protective type 1 immune response. The mechanisms by which immune cells are regulated to produce IFN-γ during T. cruzi infection are still incompletely understood. Here, we show that urokinase plasminogen activator (uPA is induced early upon T. cruzi infection, and remains elevated until day 20 post inoculation. We previously demonstrated that the inhibitory receptor Ly49E, which is expressed, among others, on NK and NKT cells, is triggered by uPA. Therefore, we compared wild type (WT to Ly49E knockout (KO mice for their control of experimental T. cruzi infection. Our results show that young, i.e. 4- and 6-week-old, Ly49E KO mice control the infection better than WT mice, indicated by a lower parasite load and less cachexia. The beneficial effect of Ly49E depletion is more obvious in 4-week-old male than in female mice and weakens in 8-week-old mice. In young mice, the lower T. cruzi parasitemia in Ly49E KO mice is paralleled by higher IFN-γ production compared to their WT controls. Our data indicate that Ly49E receptor expression inhibits the immune control of T. cruzi infection. This is the first demonstration that the inhibitory Ly49E receptor can interfere with the immune response to a pathogen in vivo.

  2. Bioenergetic profiling of Trypanosoma cruzi life stages using Seahorse extracellular flux technology.

    Science.gov (United States)

    Shah-Simpson, Sheena; Pereira, Camila F A; Dumoulin, Peter C; Caradonna, Kacey L; Burleigh, Barbara A

    2016-08-01

    Energy metabolism is an attractive target for the development of new therapeutics against protozoan pathogens, including Trypanosoma cruzi, the causative agent of human Chagas disease. Despite emerging evidence that mitochondrial electron transport is essential for the growth of intracellular T. cruzi amastigotes in mammalian cells, fundamental knowledge of mitochondrial energy metabolism in this parasite life stage remains incomplete. The Clark-type electrode, which measures the rate of oxygen consumption, has served as the traditional tool to study mitochondrial energetics and has contributed to our understanding of it in T. cruzi. Here, we evaluate the Seahorse XF(e)24 extracellular flux platform as an alternative method to assess mitochondrial bioenergetics in isolated T. cruzi parasites. We report optimized assay conditions used to perform mitochondrial stress tests with replicative life cycle stages of T. cruzi using the XF(e)24 instrument, and discuss the advantages and potential limitations of this methodology, as applied to T. cruzi and other trypanosomatids. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Modulation of Trypanosoma cruzi-specific T-cell responses after chemotherapy for chronic Chagas disease

    Directory of Open Access Journals (Sweden)

    María Cecilia Albareda

    2015-05-01

    Full Text Available The aim of this review is to describe the contributions of the knowledge of T-cell responses to the understanding of the physiopathology and the responsiveness to etiological treatment during the chronic phase of Chagas disease. T-helper (Th1 and interleukin (IL-10 Trypanosoma cruzi-specific T-cells have been linked to the asymptomatic phase or to severe clinical forms of the disease, respectively or vice versa, depending on the T. cruzi antigen source, the patient’s location and the performed immunological assays. Parasite-specific T-cell responses are modulated after benznidazole (BZ treatment in chronically T. cruzi-infected subjects in association with a significant decrease in T. cruzi-specific antibodies. Accumulating evidence has indicated that treatment efficacy during experimental infection with T. cruzi results from the combined action of BZ and the activation of appropriate immune responses in the host. However, strong support of this interaction in T. cruzi-infected humans remains lacking. Overall, the quality of T-cell responses might be a key factor in not only disease evolution, but also chemotherapy responsiveness. Immunological parameters are potential indicators of treatment response regardless of achievement of cure. Providing tools to monitor and provide early predictions of treatment success will allow the development of new therapeutic options.

  4. Catalase expression impairs oxidative stress-mediated signalling in Trypanosoma cruzi.

    Science.gov (United States)

    Freire, Anna Cláudia Guimarães; Alves, Ceres Luciana; Goes, Grazielle Ribeiro; Resende, Bruno Carvalho; Moretti, Nilmar Silvio; Nunes, Vinícius Santana; Aguiar, Pedro Henrique Nascimento; Tahara, Erich Birelli; Franco, Glória Regina; Macedo, Andréa Mara; Pena, Sérgio Danilo Junho; Gadelha, Fernanda Ramos; Guarneri, Alessandra Aparecida; Schenkman, Sergio; Vieira, Leda Quercia; Machado, Carlos Renato

    2017-09-01

    Trypanosoma cruzi is exposed to oxidative stresses during its life cycle, and amongst the strategies employed by this parasite to deal with these situations sits a peculiar trypanothione-dependent antioxidant system. Remarkably, T. cruzi's antioxidant repertoire does not include catalase. In an attempt to shed light on what are the reasons by which this parasite lacks this enzyme, a T. cruzi cell line stably expressing catalase showed an increased resistance to hydrogen peroxide (H2O2) when compared with wild-type cells. Interestingly, preconditioning carried out with low concentrations of H2O2 led untransfected parasites to be as much resistant to this oxidant as cells expressing catalase, but did not induce the same level of increased resistance in the latter ones. Also, presence of catalase decreased trypanothione reductase and increased superoxide dismutase levels in T. cruzi, resulting in higher levels of residual H2O2 after challenge with this oxidant. Although expression of catalase contributed to elevated proliferation rates of T. cruzi in Rhodnius prolixus, it failed to induce a significant increase of parasite virulence in mice. Altogether, these results indicate that the absence of a gene encoding catalase in T. cruzi has played an important role in allowing this parasite to develop a shrill capacity to sense and overcome oxidative stress.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Parasite Genome Projects and the Trypanosoma cruzi Genome Initiative

    Directory of Open Access Journals (Sweden)

    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

  7. Patients with Central Lines — What You Need to Know to Avoid a Bloodstream Infection

    Centers for Disease Control (CDC) Podcasts

    This podcast is based on the March, 2011 CDC Vital Signs report which indicates bloodstream infections in patients with central lines are largely preventable when healthcare providers use CDC-recommended infection control steps.

  8. Epidemiology and Antifungal Susceptibility of Bloodstream Candida Isolates in Quebec: Report on 453 Cases between 2003 and 2005

    Directory of Open Access Journals (Sweden)

    Guy St-Germain

    2008-01-01

    Full Text Available BACKGROUND: Between May 2003 and April 2005, a population-based surveillance of Candida bloodstream infections was conducted in Quebec. A total of 453 episodes of candidemia (464 yeast isolates from 54 participating hospitals were studied.

  9. Antiseptic barrier cap effective in reducing central line-associated bloodstream infections : A systematic review and meta-analysis

    NARCIS (Netherlands)

    Voor In 't Holt, Anne F; Helder, Onno K; Vos, Margreet C; Schafthuizen, Laura; Sülz, Sandra; van den Hoogen, Agnes; Ista, Erwin

    2017-01-01

    BACKGROUND: Microorganisms can intraluminally access a central venous catheter via the catheter hub. The catheter hub should be appropriately disinfected to prevent central line-associated bloodstream infections (CLABSIs). However, compliance with the time-consuming manual disinfection process is

  10. Cluster of Candida parapsilosis primary bloodstream infection in a neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    Carmem Lúcia P. da Silva

    Full Text Available Candida parapsilosis is an increasingly important bloodstream pathogen in neonatal intensive care units (NICU. We investigated a cluster of bloodstream infections in a NICU to determine whether nosocomial transmission occurred. During a 3-day period, 3 premature infants hospitalized in the same unit presented with sepsis caused by C. parapsilosis. Electrophoretic karyotype of the organisms was performed by using pulsed field gel electrophoresis in a countour-clamped homogeneous electric field system. The isolate from 1 newborn could not be typed, and the isolates from the remaining 2 infants had identical patterns. All 3 cases are described. We conclude that nosocomial transmission of C. parapsilosis occurred and that neonates under intensive care may represent a risk group for this pathogen.

  11. Cluster of Candida parapsilosis primary bloodstream infection in a neonatal intensive care unit

    Directory of Open Access Journals (Sweden)

    Silva Carmem Lúcia P. da

    2001-01-01

    Full Text Available Candida parapsilosis is an increasingly important bloodstream pathogen in neonatal intensive care units (NICU. We investigated a cluster of bloodstream infections in a NICU to determine whether nosocomial transmission occurred. During a 3-day period, 3 premature infants hospitalized in the same unit presented with sepsis caused by C. parapsilosis. Electrophoretic karyotype of the organisms was performed by using pulsed field gel electrophoresis in a countour-clamped homogeneous electric field system. The isolate from 1 newborn could not be typed, and the isolates from the remaining 2 infants had identical patterns. All 3 cases are described. We conclude that nosocomial transmission of C. parapsilosis occurred and that neonates under intensive care may represent a risk group for this pathogen.

  12. Whole-genome sequencing of bloodstream Staphylococcus aureus isolates does not distinguish bacteraemia from endocarditis

    DEFF Research Database (Denmark)

    Lilje, Berit; Rasmussen, Rasmus Vedby; Dahl, Anders

    2017-01-01

    Most Staphylococcus aureus isolates can cause invasive disease given the right circumstances, but it is unknown if some isolates are more likely to cause severe infections than others. S. aureus bloodstream isolates from 120 patients with definite infective endocarditis and 121 with S. aureus...... bacteraemia without infective endocarditis underwent whole-genome sequencing. Genome-wide association analysis was performed using a variety of bioinformatics approaches including SNP analysis, accessory genome analysis and k-mer based analysis. Core and accessory genome analyses found no association...... with either of the two clinical groups. In this study, the genome sequences of S. aureus bloodstream isolates did not discriminate between bacteraemia and infective endocarditis. Based on our study and the current literature, it is not convincing that a specific S. aureus genotype is clearly associated...

  13. Triatominae-Trypanosoma cruzi/T. rangeli: Vector-parasite interactions.

    Science.gov (United States)

    Vallejo, G A; Guhl, F; Schaub, G A

    2009-01-01

    Of the currently known 140 species in the family Reduviidae, subfamily Triatominae, those which are most important as vectors of the aetiologic agent of Chagas disease, Trypanosoma cruzi, belong to the tribes Triatomini and Rhodniini. The latter not only transmit T. cruzi but also Trypanosoma rangeli, which is considered apathogenic for the mammalian host but can be pathogenic for the vectors. Using different molecular methods, two main lineages of T. cruzi have been classified, T. cruzi I and T. cruzi II. Within T. cruzi II, five subdivisions are recognized, T. cruzi IIa-IIe, according to the variability of the ribosomal subunits 24Salpha rRNA and 18S rRNA. In T. rangeli, differences in the organization of the kinetoplast DNA separate two forms denoted T. rangeli KP1+ and KP1-, although differences in the intergenic mini-exon gene and of the small subunit rRNA (SSU rRNA) suggest four subpopulations denoted T. rangeli A, B, C and D. The interactions of these subpopulations of the trypanosomes with different species and populations of Triatominae determine the epidemiology of the human-infecting trypanosomes in Latin America. Often, specific subpopulations of the trypanosomes are transmitted by specific vectors in a particular geographic area. Studies centered on trypanosome-triatomine interaction may allow identification of co-evolutionary processes, which, in turn, could consolidate hypotheses of the evolution and the distribution of T. cruzi/T. rangeli-vectors in America, and they may help to identify the mechanisms that either facilitate or impede the transmission of the parasites in different vector species. Such mechanisms seem to involve intestinal bacteria, especially the symbionts which are needed by the triatomines to complete nymphal development and to produce eggs. Development of the symbionts is regulated by the vector. T. cruzi and T. rangeli interfere with this system and induce the production of antibacterial substances. Whereas T. cruzi is only

  14. Blood culture contamination with Enterococci and skin organisms: implications for surveillance definitions of primary bloodstream infections.

    Science.gov (United States)

    Freeman, Joshua T; Chen, Luke Francis; Sexton, Daniel J; Anderson, Deverick J

    2011-06-01

    Enterococci are a common cause of bacteremia but are also common contaminants. In our institution, approximately 17% of positive blood cultures with enterococci are mixed with skin organisms. Such isolates are probable contaminants. The specificity of the current definition of primary bloodstream infection could be increased by excluding enterococci mixed with skin organisms. Copyright © 2011 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Mosby, Inc. All rights reserved.

  15. Tsukamurella catheter-related bloodstream infection in a pediatric patient with pulmonary hypertension

    Directory of Open Access Journals (Sweden)

    Kristen A. Wendorf

    2010-03-01

    Full Text Available Catheter-related bloodstream infections (CR-BSI are important complications in patients with long-term indwelling central venous catheters. In this report, we present the case of a 14-year-old male with pulmonary hypertension treated with continuous treprostinil infusion, who presented with a CR-BSI caused by a Tsukamurella species. This case highlights the potential for this unusual organism to cause infection in immunocompetent patients.

  16. Efficacy of an infection control programme in reducing nosocomial bloodstream infections in a Senegalese neonatal unit.

    Science.gov (United States)

    Landre-Peigne, C; Ka, A S; Peigne, V; Bougere, J; Seye, M N; Imbert, P

    2011-10-01

    Neonatal nosocomial infections are public health threats in the developing world, and successful interventions are rarely reported. A before-and-after study was conducted in the neonatal unit of the Hôpital Principal de Dakar, Senegal to assess the efficacy of a multi-faceted hospital infection control programme implemented from March to May 2005. The interventions included clustering of nursing care, a simple algorithm for empirical therapy of suspected early-onset sepsis, minimal invasive care and promotion of early discharge of neonates. Data on nosocomial bloodstream infections, mortality, bacterial resistance and antibiotic use were collected before and after implementation of the infection control programme. One hundred and twenty-five infants were admitted immediately before the programme (Period 1, January-February 2005) and 148 infants were admitted immediately after the programme (Period 2, June-July 2005). The two groups of infants were comparable in terms of reason for admission and birth weight. After implementation of the infection control programme, the overall rate of nosocomial bloodstream infections decreased from 8.8% to 2.0% (P=0.01), and the rate of nosocomial bloodstream infections/patient-day decreased from 10.9 to 2.9/1000 patient-days (P=0.03). Overall mortality rates did not differ significantly. The proportion of neonates who received antimicrobial therapy for suspected early-onset sepsis decreased significantly from 100% to 51% of at-risk infants (Punit, simple, low-cost and sustainable interventions led to the control of a high incidence of bacterial nosocomial bloodstream infections, and the efficacy of these interventions was long-lasting. Such interventions could be extended to other low-income countries. Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  17. Chaos weak signal detecting algorithm and its application in the ultrasonic Doppler bloodstream speed measuring

    International Nuclear Information System (INIS)

    Chen, H Y; Lv, J T; Zhang, S Q; Zhang, L G; Li, J

    2005-01-01

    At the present time, the ultrasonic Doppler measuring means has been extensively used in the human body's bloodstream speed measuring. The ultrasonic Doppler measuring means can achieve the measuring of liquid flux by detecting Doppler frequency shift of ultrasonic in the process of liquid spread. However, the detected sound wave is a weak signal that is flooded in the strong noise signal. The traditional measuring method depends on signal-to-noise ratio. Under the very low signal-to-noise ratio or the strong noise signal background, the signal frequency is not measured. This article studied on chaotic movement of Duffing oscillator and intermittent chaotic characteristic on chaotic oscillator of Duffing equation. In the light of the range of the bloodstream speed of human body and the principle of Doppler shift, the paper determines the frequency shift range. An oscillator array including many oscillators is designed according to it. The reflected ultrasonic frequency information can be ascertained accurately by the intermittent chaos quality of the oscillator. The signal-to-noise ratio of -26.5 dB is obtained by the result of the experiment. Compared with the tradition the frequency method compare, the dependence to signal-to-noise ratio is lowered consumedly. The measuring precision of the bloodstream speed is heightened

  18. Value of Public Health Funding in Preventing Hospital Bloodstream Infections in the United States.

    Science.gov (United States)

    Whittington, Melanie D; Bradley, Cathy J; Atherly, Adam J; Campbell, Jonathan D; Lindrooth, Richard C

    2017-11-01

    To estimate the association of 1 activity of the Prevention and Public Health Fund with hospital bloodstream infections and calculate the return on investment (ROI). The activity was funded for 1 year (2013). A difference-in-differences specification evaluated hospital standardized infection ratios (SIRs) before funding allocation (years 2011 and 2012) and after funding allocation (years 2013 and 2014) in the 15 US states that received the funding compared with hospital SIRs in states that did not receive the funding. We estimated the association of the funded public health activity with SIRs for bloodstream infections. We calculated the ROI by dividing cost offsets from infections averted by the amount invested. The funding was associated with a 33% (P < .05) reduction in SIRs and an ROI of $1.10 to $11.20 per $1 invested in the year of funding allocation (2013). In 2014, after the funding stopped, significant reductions were no longer evident. This activity was associated with a reduction in bloodstream infections large enough to recoup the investment. Public health funding of carefully targeted areas may improve health and reduce health care costs.

  19. Procalcitonin levels in gram-positive, gram-negative, and fungal bloodstream infections.

    Science.gov (United States)

    Leli, Christian; Ferranti, Marta; Moretti, Amedeo; Al Dhahab, Zainab Salim; Cenci, Elio; Mencacci, Antonella

    2015-01-01

    Procalcitonin (PCT) can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR) 3.4-44.1) bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6-7.6) or fungal (0.5 ng/mL, IQR 0.4-1) infections (P Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919-0.969, P Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9-48.5 versus 3.5 ng/mL, IQR 0.8-21.5; P Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  20. Protein A Suppresses Immune Responses during Staphylococcus aureus Bloodstream Infection in Guinea Pigs

    Science.gov (United States)

    Kim, Hwan Keun; Falugi, Fabiana; Thomer, Lena; Missiakas, Dominique M.

    2015-01-01

    ABSTRACT   Staphylococcus aureus infection is not associated with the development of protective immunity, and disease relapses occur frequently. We hypothesize that protein A, a factor that binds immunoglobulin Fcγ and cross-links VH3 clan B cell receptors (IgM), is the staphylococcal determinant for host immune suppression. To test this, vertebrate IgM was examined for protein A cross-linking. High VH3 binding activity occurred with human and guinea immunoglobulin, whereas mouse and rabbit immunoglobulins displayed little and no binding, respectively. Establishing a guinea pig model of S. aureus bloodstream infection, we show that protein A functions as a virulence determinant and suppresses host B cell responses. Immunization with SpAKKAA, which cannot bind immunoglobulin, elicits neutralizing antibodies that enable guinea pigs to develop protective immunity. Importance  Staphylococcus aureus is the leading cause of soft tissue and bloodstream infections; however, a vaccine with clinical efficacy is not available. Using mice to model staphylococcal infection, earlier work identified protective antigens; however, corresponding human clinical trials did not reach their endpoints. We show that B cell receptor (IgM) cross-linking by protein A is an important immune evasion strategy of S. aureus that can be monitored in a guinea pig model of bloodstream infection. Further, immunization with nontoxigenic protein A enables infected guinea pigs to elicit antibody responses that are protective against S. aureus. Thus, the guinea pig model may support preclinical development of staphylococcal vaccines. PMID:25564466

  1. [Seroprevalence of T. cruzi infection in Canis familiaris, state of Sucre, Venezuela].

    Science.gov (United States)

    Berrizbeitia, Mariolga; Concepción, Juan Luis; Carzola, Valentina; Rodríguez, Jéssicca; Cáceres, Ana; Quiñones, Wilfredo

    2013-01-01

    Trypanosoma cruzi infection in humans has been extensively studied in Venezuela; however, in reservoirs it has been less investigated. The objective of this study was to determine the seroepidemiology of T. cruzi in the state of Sucre, Venezuela. A cross-sectional and prospective study conducted in 95 towns and 577 dwellings in the 15 municipalies of the state of Sucre, Venezuela, from August to November, 2008. The evaluation of serum samples was performed with the CruziELISA kit and the multiple antigens binding assays (MABA). Furthermore, epidemiological surveys were applied to evaluate the risk factors. A total of dogs (average age of 2, 6 + 2.2 years, 226 males and 137 females) was evaluated. The combination of the ELISA / MABA tests detected 78 positive sera, sixty-nine negative and 10 of inconclusive results. The seroprevalence of the T. cruzi infection in dogs in the state of Sucre, was 22.1% (CI 95%: 20.58-22.4%). No significant statistic association was found between the T. cruzi infection in dogs and the evaluated epidemiological variables: hunting dogs that slept oudoors roaming freely in the populated center, sex of the animal and eating habits. The T. cruzi infection was associated to the age of canines, being significantly higher in the group of 0 to 3 years, when compared with older dogs. The high T. cruzi seroprevalence dected in dogs shows that in this región of Venezuela there prevails an important risk factor of transmissibility of this parasite to human populations.

  2. Trypanosoma cruzi in dogs: electrocardiographic and echocardiographic evaluation, in Malinalco, State of Mexico

    Directory of Open Access Journals (Sweden)

    González-Vieyra SD

    2011-12-01

    Full Text Available Sandra Díaz González-Vieyra1, Ninfa Ramírez-Durán2, Ángel H Sandoval-Trujillo3, Juan C Vázquez-Chagoyán1, Humberto G Monroy-Salazar1, Alberto Barbabosa-Pliego11Research Center of Advanced Studies in Animal Health, Veterinary Husbandry School, 2Medical and Ambiental Microbiology, Research Center of Advanced Studies in Health Science, School of Medicine, Autonomous University of the State of Mexico, Toluca, Mexico; 3Department of Biological Systems, Metropolitan Autonomous University, Xochimilco, Mexico City, MexicoAbstract: Chagas disease caused by Trypanosoma cruzi is an important public health problem in Latin America. Dogs are considered a risk factor for human Chagas disease, a sentinel for T. cruzi infection in endemic regions and an animal model to study pathological aspects of the disease. The potential use of dogs as indicators of human cardiac pathogenicity of local T. cruzi strains has been studied insufficiently. We studied electrocardiographic (EKG and echocardiographic (ECG alteration frequencies observed in an open population of dogs in Malinalco, Mexico, and determined if such frequencies were statistically associated with T. cruzi infection in dogs. Animals (n = 139 were clinically examined and owners were asked to answer a questionnaire about dogs’ living conditions. Two commercial serological tests (IHA, ELISA were conducted to detect anti-T. cruzi serum antibodies. Significant differences between seropositive and seronegative animals in cardiomyopathic frequencies were detected through EKG and ECG (P < 0.05. Thirty dogs (21.58% were serologically positive to anti-T. cruzi antibodies (to ELISA and IHA assays, of which nine (30% had EKG and/or ECG alterations. From the remaining 104 (78.42% seronegative animals, five (4.5% had EKG and/or ECG abnormalities. Our data support the hypothesis that most EKG and ECG alterations found in dogs from Malinalco could be associated with T. cruzi infection. Considering the dog as a

  3. Clinical and epidemiological features of chronic Trypanosoma cruzi infection in patients with HIV/AIDS in Buenos Aires, Argentina.

    Science.gov (United States)

    Benchetrit, Andrés Guillermo; Fernández, Marisa; Bava, Amadeo Javier; Corti, Marcelo; Porteiro, Norma; Martínez Peralta, Liliana

    2018-02-01

    Trypanosoma cruzi reactivation in HIV patients is considered an opportunistic infection, usually with a fatal outcome. The aim of this study was to describe the epidemiological and clinical features of T. cruzi infection in HIV patients and to compare these findings between patients with and without Chagas disease reactivation. The medical records of T. cruzi-HIV co-infected patients treated at the Muñiz Infectious Diseases Hospital from January 2005 to December 2014 were reviewed retrospectively. Epidemiological and clinical features were assessed and compared between patients with and without Chagas disease reactivation. The medical records of 80 T. cruzi-HIV co-infected patients were reviewed. The most likely route of T. cruzi infection was vector-borne (32/80 patients), followed by intravenous drug use (12/80). Nine of 80 patients had reactivation. Patients without reactivation had a significantly higher CD4 T-cell count at diagnosis of T. cruzi infection (144 cells/μl vs. 30 cells/μl, p=0.026). Chagas disease serology was negative in two of nine patients with reactivation. Serological assays for T. cruzi infection may be negative in severely immunocompromised patients. Direct parasitological techniques should be performed in the diagnosis of patients for whom there is a suspicion of T. cruzi reactivation. HIV patients with a lower CD4 count are at higher risk of reactivation. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  4. Usefulness of microsatellite typing in population genetic studies of Trypanosoma cruzi

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    Macedo Andrea M

    2001-01-01

    Full Text Available Through microsatellite analysis of 53 monoclonal populations of Trypanosoma cruzi, we found a remarkable degree of genetic polymorphism with no single multilocus genotype being observed more than once. The microsatellite profile proved to be stable during 70 generations of the CL Brener clone in culture. The microsatellite profiling presented also high diagnostic sensitivity since DNA amplifications could be achieved with less than 100 fg DNA, corresponding to half parasite total DNA content. Based on these technical attributes the microsatellite assay turns out to be an important tool for direct typing T. cruzi in biological samples. By using this approach we were able to type T. cruzi in feces of artificially infected bugs and in single cells sorted by FACS. The microsatellites have shown to be excellent markers for T. cruzi phylogenetic reconstruction. We used maximum parsimony based on the minimum number of mutational steps to build an unrooted Wagner network, which confirms previous conclusions based on the analysis of the D7 domain of the LSU rDNA gene that T. cruzi is composed by two major groups. We also obtained evidence that strains belonging to rRNA group 2 are subdivided into two genetically distant clusters, and that one of these clusters is more related to rRNA group 1/2. These results suggest different origins for these strains.

  5. 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.

  6. 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.

  7. Effects of buthionine sulfoximine nifurtimox and benznidazole upon trypanothione and metallothionein proteins in Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    JUAN DIEGO MAYA

    2004-01-01

    Full Text Available Proteins rich in sulfhydryl groups, such as metallothionein, are present in several strains of the parasite Trypanosoma cruzi, the etiological agent of Chagas' disease. Metallothionein-like protein concentrations ranged from 5.1 to 13.2 pmol/mg protein depending on the parasite strain and growth phase. Nifurtimox and benznidazole, used in the treatment of Chagas' disease, decreased metallothionein activity by approximately 70%. T. cruzi metallothionein was induced by ZnCl2. Metallothionein from T. cruzi was partially purified and its monobromobimane derivative showed a molecular weight of approximately 10,000 Da by SDS-PAGE analysis. The concentration of trypanothione, the major glutathione conjugate in T. cruzi, ranged from 3.8 to 10.8 nmol/mg protein, depending on the culture phase. The addition of buthionine sulfoximine to the protozoal culture considerably reduced the concentration of trypanothione and had no effect upon the metallothionein concentration. The possible contribution of metallothionein-like proteins to drug resistance in T. cruzi is discussed.

  8. 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.

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

    Science.gov (United States)

    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.

  10. The Trypanosoma cruzi Protein TcHTE Is Critical for Heme Uptake.

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    Marcelo L Merli

    2016-01-01

    Full Text Available Trypanosoma cruzi, the etiological agent of Chagas' disease, presents nutritional requirements for several metabolites. It requires heme for the biosynthesis of several heme-proteins involved in essential metabolic pathways like mitochondrial cytochromes and respiratory complexes, as well as enzymes involved in the biosynthesis of sterols and unsaturated fatty acids. However, this parasite lacks a complete route for its synthesis. In view of these facts, T. cruzi has to incorporate heme from the environment during its life cycle. In other words, their hosts must supply the heme for heme-protein synthesis. Although the acquisition of heme is a fundamental issue for the parasite's replication and survival, how this cofactor is imported and distributed is poorly understood. In this work, we used different fluorescent heme analogs to explore heme uptake along the different life-cycle stages of T. cruzi, showing that this parasite imports it during its replicative stages: the epimastigote in the insect vector and the intracellular amastigote in the mammalian host. Also, we identified and characterized a T. cruzi protein (TcHTE with 55% of sequence similarity to LHR1 (protein involved in L. amazonensis heme transport, which is located in the flagellar pocket, where the transport of nutrients proceeds in trypanosomatids. We postulate TcHTE as a protein involved in improving the efficiency of the heme uptake or trafficking in T. cruzi.

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

    Directory of Open Access Journals (Sweden)

    Grisard Edmundo C

    2000-01-01

    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.

  12. Extracellular Trap Formation in Response to Trypanosoma cruzi Infection in Granulocytes Isolated From Dogs and Common Opossums, Natural Reservoir Hosts

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    Nicole de Buhr

    2018-05-01

    Full Text Available Granulocytes mediate the first line of defense against infectious diseases in humans as well as animals and they are well known as multitasking cells. They can mediate antimicrobial activity by different strategies depending on the pathogen they encounter. Besides phagocytosis, a key strategy against extracellular pathogens is the formation of extracellular traps (ETs. Those ETs mainly consist of DNA decorated with antimicrobial components and mediate entrapment of various pathogens. In the last years, various studies described ET formation as response to bacteria, viruses and parasites e.g., Trypanosma (T. cruzi. Nevertheless, it is not fully understood, if ET formation helps the immune system to eliminate intracellular parasites. The goal of this study was to analyze ET formation in response to the intracellular parasite Trypanosma (T. cruzi by granulocytes derived from animals that serve as natural reservoir. Thus, we investigated the ET formation in two T. cruzi reservoirs, namely dogs as domestic animal and common opossums (Didelphis marsupialis as wild animal. Granulocytes were harvested from fresh blood by density gradient centrifugation and afterwards incubated with T. cruzi. We conducted the analysis by determination of free DNA and immunofluorescence microscopy. Using both methods, we show that T. cruzi efficiently induces ET formation in granulocytes derived from common opossum as well as dog blood. Most ETs from both animal species as response to T. cruzi are decorated with the protease neutrophil elastase. Since T. cruzi is well known to circulate over years in both analyzed animals as reservoirs, it may be assumed that T. cruzi efficiently evades ET-mediated killing in those animals. Therefore, ETs may not play a major role in efficient elimination of the pathogen from the blood of dogs or common opossums as T. cruzi survives in niches of their body. The characterization of granulocytes in various animals and humans may be helpful

  13. 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.

  14. [Seroprevalence of Trypanosoma cruzi infection in the rural population of Sucre State, Venezuela].

    Science.gov (United States)

    García-Jordán, Noris; Berrizbeitia, Mariolga; Rodríguez, Jessicca; Concepción, Juan Luis; Cáceres, Ana; Quiñones, Wilfredo

    2017-10-26

    The current study aimed to determine the seroprevalence of Trypanosoma cruzi infection in Sucre State, Venezuela, and its association with epidemiological risk factors. The cluster sampling design allowed selecting 96 villages and 576 dwellings in the State's 15 municipalities. A total of 2,212 serum samples were analyzed by ELISA, HAI, and IFI. Seroprevalence in Sucre State was 3.12%. Risk factors associated with T. cruzi infection were: accumulated garbage, flooring and wall materials, type of dwelling, living in a house with wattle and daub walls and/or straw roofing, living in a house with risky walls and roofing, risky buildings and wattle and daub outbuildings, poultry inside the human dwelling, and presence of firewood. Infection was associated with individual age, and three seropositive cases were found in individuals less than 15 years of age. Sucre State has epidemiological factors that favor the risk of acquiring T. cruzi infection.

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

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    Manuel Ruiz-Garcia

    2001-01-01

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

  16. Vaccination with Trypanosoma rangeli induces resistance of guinea pigs to virulent Trypanosoma cruzi.

    Science.gov (United States)

    Basso, B; Moretti, E; Fretes, R

    2014-01-15

    Chagas' disease, endemic in Latin America, is spread in natural environments through animal reservoirs, including marsupials, mice and guinea pigs. Farms breeding guinea pigs for food are located in some Latin-American countries with consequent risk of digestive infection. The aim of this work was to study the effect of vaccination with Trypanosoma rangeli in guinea pigs challenged with Trypanosoma cruzi. Animals were vaccinated with fixated epimastigotes of T. rangeli, emulsified with saponin. Controls received only PBS. Before being challenged with T. cruzi, parasitemia, survival rates and histological studies were performed. The vaccinated guinea pigs revealed significantly lower parasitemia than controls (pguinea pigs and dogs. The development of vaccines for use in animals, like domestic dogs and guinea pigs in captivity, opens up new opportunities for preventive tools, and could reduce the risk of infection with T. cruzi in the community. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. The isolation and identification of Trypanosoma cruzi from raccoons in Maryland

    Science.gov (United States)

    Walton, B.C.; Bauman, P.M.; Diamond, L.S.; Herman, C.M.

    1958-01-01

    Five raccoons trapped at Patuxent Research Refuge, Laurel, Maryland, were found to have trypanosomes in the blood which were morphologically indistinguishable from Trypanosoma cruzi on stained smears. The organism grew well in culture. It developed and reproduced in Triatoma protracta, T. infestans, T. phyllosoma, and Rhodnius prolixus. Experimental infections were produced in raccoons, opossums, mice, rats, and monkeys by inoculation of blood, culture, and triatome forms. Typical leishmaniform bodies were found in tissue sections of cardiac muscle fibers from naturally and experimentally infected animals. Cross agglutinations carried out with Iiving cultural forms and rabbit antisera demonstrated a close antigenic relationship between the raccoon trypanosome and T. cruzi (Brazil strain). On the basis of (1) morphology, (2) presence of leishmaniform tissue stages, (3) development in triatomes, (4) infectivity to a variety of mammals, (5) culture characteristics, and (6) cross reactions in serological tests, this parasite is considered conspecific with Trypanosoma cruzi (Chagas, 1909), the causative agent of American human trypanosomiasis.

  18. [Trypanosoma cruzi in triatomines from Nuevo Leon, Mexico].

    Science.gov (United States)

    Molina-Garza, Zinnia Judith; Rosales-Encina, José Luis; Galaviz-Silva, Lucio; Molina-Garza, Daniel

    2007-01-01

    To determine the prevalence of Trypanosoma cruzi in triatomines from Nuevo León using the standardization of an improved enzyme-linked immunosorbent assay test. From July to September 2005, 52 triatomines were captured in General Terán, a municipality located in Nuevo León. They were analyzed using optical microscopy (OM) and a polymerase chain reaction (PCR), as standards of reference, to develop a technique for detecting the parasite using enzyme-linked immunosorbent assay (ELISA). Using OM and PCR, 31 triatomines were found to be positive and 21 negative. Using ELISA, 27 samples were identified as positive and 25 negative (specificity 100%, sensitivity 87%, negative predictive value 84%, and positive predictive value 100%). The prevalence of infected triatomines was 59.61% with OM and PCR, and 51.92% with ELISA. Our data confirm that the ELISA assay in triatomines is a fast, reliable and useful tool. Since it was possible to simultaneously analyze a large number of samples with high sensibility and specificity values, the ELISA test proves to be useful for new epidemiologic studies having a high number of vectors. It is also less expensive than PCR. It is therefore recommended for epidemiological and preventive surveillance programs as a first screening test before conducting a confirmatory test using PCR.

  19. mRNA localization mechanisms in Trypanosoma cruzi.

    Directory of Open Access Journals (Sweden)

    Lysangela R Alves

    Full Text Available Asymmetric mRNA localization is a sophisticated tool for regulating and optimizing protein synthesis and maintaining cell polarity. Molecular mechanisms involved in the regulated localization of transcripts are widespread in higher eukaryotes and fungi, but not in protozoa. Trypanosomes are ancient eukaryotes that branched off early in eukaryote evolution. We hypothesized that these organisms would have basic mechanisms of mRNA localization. FISH assays with probes against transcripts coding for proteins with restricted distributions showed a discrete localization of the mRNAs in the cytoplasm. Moreover, cruzipain mRNA was found inside reservosomes suggesting new unexpected functions for this vacuolar organelle. Individual mRNAs were also mobilized to RNA granules in response to nutritional stress. The cytoplasmic distribution of these transcripts changed with cell differentiation, suggesting that localization mechanisms might be involved in the regulation of stage-specific protein expression. Transfection assays with reporter genes showed that, as in higher eukaryotes, 3'UTRs were responsible for guiding mRNAs to their final location. Our results strongly suggest that Trypanosoma cruzi have a core, basic mechanism of mRNA localization. This kind of controlled mRNA transport is ancient, dating back to early eukaryote evolution.

  20. Using a Microfluidic-Microelectric Device to Directly Separate Serum/Blood Cells from a Continuous Whole Bloodstream Flow

    Science.gov (United States)

    Wang, Ming-Wen; Jeng, Kuo-Shyang; Yu, Ming-Che; Su, Jui-Chih

    2012-03-01

    To make the rapid separation of serum/blood cells possible in a whole bloodstream flow without centrifugation and Pasteur pipette suction, the first step is to use a microchannel to transport the whole bloodstream into a microdevice. Subsequently, the resulting serum/blood cell is separated from the whole bloodstream by applying other technologies. Creating the serum makes this subsequent separation possible. To perform the actual separation, a microchannel with multiple symmetric curvilinear microelectrodes has been designed on a glass substrate and fabricated with micro-electromechanical system technology. The blood cells can be observed clearly by black-field microscopy imaging. A local dielectrophoretic (DEP) force, obtained from nonuniform electric fields, was used for manipulating and separating the blood cells from a continuous whole bloodstream. The experimental studies show that the blood cells incur a local dielectrophoretic field when they are suspended in a continuous flow (v = 0.02-0.1 cm/s) and exposed to AC fields at a frequency of 200 kHz. Using this device, the symmetric curvilinear microelectrodes provide a local dielectrophoretic field that is sufficiently strong for separating nearby blood cells and purifying the serum in a continuous whole bloodstream flow.

  1. Temporal Trends in Enterobacter Species Bloodstream Infection: A Population-Based Study, 1998-2007

    Science.gov (United States)

    Al-Hasan, Majdi N.; Lahr, Brian D.; Eckel-Passow, Jeanette E.; Baddour, Larry M.

    2010-01-01

    Enterobacter species are the fourth most common cause of gram-negative bloodstream infection (BSI). We examined temporal changes and seasonal variation in the incidence rate of Enterobacter spp. BSI, estimated 28-day and 1-year mortality, and determined in vitro antimicrobial resistance rates of Enterobacter spp. bloodstream isolates in Olmsted County, Minnesota, from 1/1/1998 to 12/31/2007. Multivariable Poisson regression was used to examine temporal changes and seasonal variation in incidence rate and Kaplan-Meier method to estimate 28-day and 1-year mortality. The median age of patients with Enterobacter spp. BSI was 58 years and 53% were female. The overall age- and gender-adjusted incidence rate of Enterobacter spp. BSI was 3.3/100,000 person-years (95% confidence interval [CI]: 2.3-4.4). There was a linear trend of increasing incidence rate from 0.8 (95% CI: 0-1.9) to 6.2 (95% CI: 3.0-9.3) per 100,000 person-years between 1998 and 2007 (p=0.002). There was no significant difference in the incidence rate of Enterobacter spp. BSI during the warmest four months compared to the remainder of the year (incidence rate ratio 1.06 [95% CI: 0.47-2.01]). The overall 28-day and 1-year mortality rates of Enterobacter spp. BSI were 21% (95% CI: 8-34%) and 38% (95% CI: 22-53%), respectively. Up to 13% of Enterobacter spp. bloodstream isolates were resistant to third-generation cephalosporins. To our knowledge, this is the first population-based study to describe the epidemiology and outcome of Enterobacter spp. BSI. The increase in incidence rate of Enterobacter spp. BSI over the past decade, coupled with its associated antimicrobial resistance, dictate more investigation of this syndrome. PMID:20518795

  2. Nosocomial bloodstream infection in a tertiary care paediatric intensive care unit

    International Nuclear Information System (INIS)

    Hamid, M.H.; Maqbool, S.

    2007-01-01

    To determine the frequency, causative organisms and susceptibility pattern of nosocomial bloodstream infections in children. All children admitted to the unit during the study period were daily evaluated for features suggestive of nosocomial infection. In addition to other investigations, blood cultures were done in all suspected cases for the confirmation of nosocomial bloodstream infection (BSI). Nosocomial infection was defined according to the criteria set by Centre for Disease Control and Prevention. Demographic, microbiological and other variables were carefully studied to analyze frequency, incidence rate, spectrum of isolates and susceptibility pattern. Children with and without nosocomial BSI were compared with regard to age, duration of stay in hospital, need and duration of ventilation and the outcome. Of the total 406 admissions, 134 children were suspected to have nosocomial infection on at least 214 occasions (episodes). Blood cultures yielded growth of pathological organisms in 62 of these episodes, giving the frequency of nosocomial BSI as 15.2 per 100 admissions (62/406 episodes). Children with nosocomial bloodstream infection were found to have younger mean age (2.1 vs. 4.1 years), longer average duration of stay (13.1 vs. 6.6 days), more frequent need for ventilation (64% vs. 34%) and longer duration of ventilation (9.7 vs. 4.8 days). Majority of isolates (77%) were gram-negative bacteria; Klebsiella being the most common isolate (n= 23). Aztreonam, Ceftiazidime, Ceforuxime and Ciprofloxacin showed high resistance pattern (33-50%). Isolates showed good sensitivity to Vancomycin (100%), Imipenem (80%), Meropenem (100%) and Co-amoxiclav (88%). The frequency of nosocomial BSI in the observed setting was quite high, having marked impact on the duration of stay and outcome. Emergence of resistant pathogens is alarming. (author)

  3. Procalcitonin Levels in Gram-Positive, Gram-Negative, and Fungal Bloodstream Infections

    Directory of Open Access Journals (Sweden)

    Christian Leli

    2015-01-01

    Full Text Available Procalcitonin (PCT can discriminate bacterial from viral systemic infections and true bacteremia from contaminated blood cultures. The aim of this study was to evaluate PCT diagnostic accuracy in discriminating Gram-positive, Gram-negative, and fungal bloodstream infections. A total of 1,949 samples from patients with suspected bloodstream infections were included in the study. Median PCT value in Gram-negative (13.8 ng/mL, interquartile range (IQR 3.4–44.1 bacteremias was significantly higher than in Gram-positive (2.1 ng/mL, IQR 0.6–7.6 or fungal (0.5 ng/mL, IQR 0.4–1 infections (P<0.0001. Receiver operating characteristic analysis showed an area under the curve (AUC for PCT of 0.765 (95% CI 0.725–0.805, P<0.0001 in discriminating Gram-negatives from Gram-positives at the best cut-off value of 10.8 ng/mL and an AUC of 0.944 (95% CI 0.919–0.969, P<0.0001 in discriminating Gram-negatives from fungi at the best cut-off of 1.6 ng/mL. Additional results showed a significant difference in median PCT values between Enterobacteriaceae and nonfermentative Gram-negative bacteria (17.1 ng/mL, IQR 5.9–48.5 versus 3.5 ng/mL, IQR 0.8–21.5; P<0.0001. This study suggests that PCT may be of value to distinguish Gram-negative from Gram-positive and fungal bloodstream infections. Nevertheless, its utility to predict different microorganisms needs to be assessed in further studies.

  4. suPAR remains uninfluenced by surgery in septic patients with bloodstream infection

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    Rabensteiner, Jasmin

    2016-07-01

    Full Text Available Surgical trauma induces activation of the immune system and may cause an increase of inflammatory biomarkers tested postoperatively in septic patients treated for bloodstream infection. The aim of this study was to determine the impact of surgical interventions on the novel sepsis biomarker soluble urokinase plasminogen activator receptor (suPAR and to compare results with those of routine laboratory parameters CRP, PCT, and IL-6 in patients with culture-proven bloodstream infection. Forty-six adult patients with positive blood culture undergoing minor or major surgical intervention were investigated, 12 blood culture positive patients served as control group. Blood was collected 24 hours before and after surgical intervention for determination of the sepsis biomarkers suPAR, CRP, PCT, and IL-6. Within the surgical study cohort, a non-significant increase of suPAR, CRP, and PCT was observed postoperatively ( 0.642; 0.773; 0.087. In contrast, a slight decrease of IL-6 ( 0.599 was observed. A significant correlation was calculated for the pre- and postoperative difference of CRP ( 0.028 and PCT and type of surgical intervention received: after minor surgical intervention only PCT decreased significantly (<0.001, while after major surgical interventions no significant differences were observed for all biomarkers evaluated. In the control group, a significant decrease of CRP ( 0.005 and PCT ( 0.005 was observed. In patients treated adequately for bloodstream infections, postoperative suPAR levels remained uninfluenced of the surgical trauma and might therefore be a reliable parameter for postoperative infectious monitoring. After minor surgical intervention, PCT seems to be the most reliable parameter.

  5. Leukoreduction by centrifugation does not eliminate Trypanosoma cruzi from infected blood units.

    Science.gov (United States)

    Dzib, Doris; Hernández, Virginia Peña; Ake, Baldemar Canche; López, Ruth Alacantara; Monteón, Victor Manuel

    2009-06-01

    Current strategies to prevent transfusion-associated Chagas disease include the identification of Trypanosoma cruzi-infected blood donors through questionnaires and serologic tests. There are other procedures such as leukoreduction that prevent the transmission of infectious agents associated to white cells. The objective of the present work was to estimate the seroprevalence, evaluate the efficacy of leukoreduction by centrifugation to eliminate T. cruzi in infected blood units, and the correlation of immunoglobulin G (IgG) subclasses of seropositive blood donors with chronic chagasic cardiopathy. Over a period of 14 months, 33 out of 6600 blood donors (0.5%) at Centro Estatal de la Transfusión Sanguínea in Campeche State, México were seropositive for T. cruzi. Twenty seropositive blood units were submitted through leukoreduction by centrifugation, and in the fractions generated (red cell fraction, platelets, and the buffy-coat), we searched for the presence of T. cruzi using specific polymerase chain reaction. We detected parasite DNA in 50% to 60% of the fractions tested, suggesting that leukoreduction by centrifugation does not eliminate the microorganisms in the infected blood unit. We also observed that the level of IgG2 and IgG4 subclasses specific for T. cruzi in seropositive blood donors was lower than in chronic cardiopathic chagasic patients. In conclusion, leukoreduction by centrifugation has a limited role in eliminating T. cruzi in infected blood supply, and the low level of specific IgG2 and IgG4 could be a marker in the indeterminate phase of infection.

  6. Trypanosoma cruzi Detection in Colombian Patients with a Diagnosis of Esophageal Achalasia.

    Science.gov (United States)

    Panesso-Gómez, Santiago; Pavia, Paula; Rodríguez-Mantilla, Iván Enrique; Lasso, Paola; Orozco, Luis A; Cuellar, Adriana; Puerta, Concepción J; Mendoza de Molano, Belén; González, John M

    2018-03-01

    Achalasia is a motility disorder of the esophagus that might be secondary to a chronic Trypanosoma cruzi infection. Several studies have investigated esophageal achalasia in patients with Chagas disease (CD) in Latin America, but no related studies have been performed in Colombia. The goals of the present study were to determine the presence of anti- T. cruzi antibodies in patients with esophageal achalasia who visited a referral hospital in Bogotá, Colombia, and to detect the presence of the parasite and its discrete typing units (DTUs). This cross-sectional study was conducted in adult patients (18-65 years old) who were previously diagnosed with esophageal achalasia and from whom blood was drawn to assess antibodies against T. cruzi using four different serological tests. Trypanosoma cruzi DNA was detected by conventional polymerase chain reaction (cPCR) and quantitative polymerase chain reaction (qPCR). In total, 38 patients, with an average age of 46.6 years (standard deviation of ±16.2) and comprising 16 men and 22 women, were enrolled. Five (13.15%) patients were found to be positive for anti- T. cruzi antibodies by indirect immunofluorescence assay (IFA), and two patients who were negative according to IFA were reactive by both enzyme-linked immunosorbent assay and immunoblot (5.3%). Parasite DNA was detected in two of these seven patients by cPCR and in one of these by qPCR. The parasite DTU obtained was TcI. In summary, this study identified T. cruzi in Colombian patients with esophageal achalasia, indicating that digestive compromise could also be present in patients with chronic CD.

  7. Congenital transmission of Trypanosoma cruzi in Argentina, Honduras, and Mexico: study protocol

    Science.gov (United States)

    2013-01-01

    Background Trypanosoma cruzi has been divided into Discrete Typing Units I and non-I (II-VI). T. cruzi I is predominant in Mexico and Central America, while non-I is predominant in most of South America, including Argentina. Little is known about congenital transmission of T. cruzi I. The specific aim of this study is to determine the rate of congenital transmission of T. cruzi I compared to non-I. Methods/design We are conducting a prospective study to enroll at delivery, 10,000 women in Argentina, 7,500 women in Honduras, and 13,000 women in Mexico. We are measuring transmitted maternal T. cruzi antibodies by performing two rapid tests in cord blood (Stat-Pak, Chembio, Medford, New York, and Trypanosoma Detect, InBios, Seattle, Washington). If at least one of the results is positive, we are identifying infants who are congenitally infected by performing parasitological examinations on cord blood and at 4–8 weeks, and serological follow-up at 10 months. Serological confirmation by ELISA (Wiener, Rosario, Argentina) is performed in cord and maternal blood, and at 10 months. We also are performing T. cruzi standard PCR, real-time quantitative PCR and genotyping on maternal venous blood and on cord blood, and serological examinations on siblings. Data are managed by a Data Center in Montevideo, Uruguay. Data are entered online at the sites in an OpenClinica data management system, and digital pictures of data forms are sent to the Data Center for quality control. Weekly reports allow for rapid feedback to the sites. Trial registration Observational study with ClinicalTrials.gov Identifier NCT01787968 PMID:24119247

  8. Central Venous Catheters and Bloodstream Infection During Induction Therapy in Children With Acute Lymphoblastic Leukemia

    DEFF Research Database (Denmark)

    Bergmann, Kristin; Hasle, Henrik; Asdahl, Peter

    2016-01-01

    The purpose of the study was to assess the risk of firsttime bloodstream infection (BSI) according to type of central venous catheter (CVC) during induction therapy in children with acute lymphoblastic leukemia (ALL). Patients eligible for our analysis were all newly diagnosed children with ALL......-negative blood isolates occurred more frequently in patients with a TE, and that lower incidences of BSI were detected in patients older than 9 years with a TE, and in patients with T-ALL. It is concluded that the type of CVC inserted at diagnosis has no impact upon the risk of BSI in patients with ALL...

  9. Clinical and molecular epidemiology of Acinetobacter baumannii bloodstream infections in an endemic setting.

    Science.gov (United States)

    Marchaim, Dror; Levit, Dana; Zigron, Roy; Gordon, Michal; Lazarovitch, Tsillia; Carrico, Joao A; Chalifa-Caspi, Vered; Moran-Gilad, Jacob

    2017-03-01

    The transmission dynamics of Acinetobacter baumannii in endemic settings, and the relation between microbial properties and patients' clinical outcomes, are yet obscure and hampered by insufficient metadata. Of 20 consecutive patients with A. baumannii bloodstream infection that were thoroughly analyzed at a single center, at least one transmission opportunity was evident for 85% of patients. This implies that patient-to-patient transmission is the major mode of A. baumannii acquisitions in health facilities. Moreover, all patients who died immediately (baumannii ST457 lineage compared with other strains.

  10. Optimizing empiric therapy for Gram-negative bloodstream infections in children.

    Science.gov (United States)

    Chao, Y; Reuter, C; Kociolek, L K; Patel, R; Zheng, X; Patel, S J

    2018-06-01

    Antimicrobial stewardship can be challenging in children with bloodstream infections (BSIs) caused by Gram-negative bacilli (GNB). This retrospective cohort study explored how data elements in the electronic health record could potentially optimize empiric antibiotic therapy for BSIs caused by GNB, via the construction of customized antibiograms for categorical GNB infections and identification of opportunities to minimize organism-drug mismatch and decrease time to effective therapy. Our results suggest potential strategies that could be implemented at key decision points in prescribing at initiation, modification, and targeting of therapy. Copyright © 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

  11. Catheter-Related Bloodstream Infections in Adults Receiving Home Parenteral Nutrition

    DEFF Research Database (Denmark)

    Tribler, Siri; Brandt, Christopher F; Hvistendahl, Mark

    2018-01-01

    BACKGROUND: A common complication in patients receiving home parenteral nutrition (HPN) is catheter-related bloodstream infections (CRBSIs). The CRBSI incidence has been advocated as an outcome parameter assessing the quality of care. This study aimed to illustrate how the use of different CRBSI......) and European Society for Clinical Nutrition (ESPEN) CRBSI criteria. Employing a catheter-salvaging strategy, 40% of the CRBSI diagnoses were supported by the paired blood culture positivity criteria and only 6% by a positive catheter tip. In 53%, CRBSIs were categorized as a clinical or "probable CRBSI...

  12. [Catheter-associated bloodstream infections: implementation of a new consensus protocol].

    Science.gov (United States)

    Urrea Ayala, M; Rozas Quesada, L

    2009-07-01

    Catheter-associated bloodstream infection is highly prevalent and often associated with fatal complications. Some studies have shown that applying preventive interventions could help to reduce and control this type of infection. To determine whether a new consensus protocol for the manipulation and maintenance of central venous catheters would decrease catheter-associated bloodstream infections (CA-BSIs) in paediatric patients. To evaluate its compliance in intensive care units. Prospective study in the paediatric (PICU) and neonatal (NICU) intensive cares units, haematology, oncology and hospital wards in a Maternal and Paediatric reference Hospital in Barcelona. The study period is divided into two periods: before (first semester) and after the start of the new protocol (second semester) in 2007. The most important changes have been the insertion of the hermetic connection in the proximal and distal site (between the line and the syringe) of the central venous catheter (CVC), the labelling of the medication line and the CVC with the date of placement. A check-list to evaluate compliance was introduced in both intensive care units (paediatrics and neonatal) during the second study period. The rates of bloodstream infection per 1000 catheter-days were assessed. The rate of bloodstream infections per 1000 catheter-days before and after the start of the new protocol was 5.7 and 4.9 in PICU; 24.6 and 18.0 in NICU; 7.6 and 4.6 in haematology-oncology, and 11.9 and 10.3 in hospital wards. As regards compliance to the protocol, we found that proximal sealed connectors were used in more than 95% of the cases and up to 85% of the central venous catheter were labelled with the insertion date in both intensive care units. A consensus protocol for the use and maintenance of central venous catheters and healthcare worker training helped to control the rate of CA-BSIs. We reaffirm the importance of epidemiological surveillance as a measure for controlling nosocomial infections.

  13. Molecular Diversity of Trypanosoma cruzi Detected in the Vector Triatoma protracta from California, USA.

    Directory of Open Access Journals (Sweden)

    Lisa A Shender

    2016-01-01

    Full Text Available Trypanosoma cruzi, causative agent of Chagas disease in humans and dogs, is a vector-borne zoonotic protozoan parasite that can cause fatal cardiac disease. While recognized as the most economically important parasitic infection in Latin America, the incidence of Chagas disease in the United States of America (US may be underreported and even increasing. The extensive genetic diversity of T. cruzi in Latin America is well-documented and likely influences disease progression, severity and treatment efficacy; however, little is known regarding T. cruzi strains endemic to the US. It is therefore important to expand our knowledge on US T. cruzi strains, to improve upon the recognition of and response to locally acquired infections.We conducted a study of T. cruzi molecular diversity in California, augmenting sparse genetic data from southern California and for the first time investigating genetic sequences from northern California. The vector Triatoma protracta was collected from southern (Escondido and Los Angeles and northern (Vallecito California regions. Samples were initially screened via sensitive nuclear repetitive DNA and kinetoplast minicircle DNA PCR assays, yielding an overall prevalence of approximately 28% and 55% for southern and northern California regions, respectively. Positive samples were further processed to identify discrete typing units (DTUs, revealing both TcI and TcIV lineages in southern California, but only TcI in northern California. Phylogenetic analyses (targeting COII-ND1, TR and RB19 genes were performed on a subset of positive samples to compare Californian T. cruzi samples to strains from other US regions and Latin America. Results indicated that within the TcI DTU, California sequences were similar to those from the southeastern US, as well as to several isolates from Latin America responsible for causing Chagas disease in humans.Triatoma protracta populations in California are frequently infected with T. cruzi

  14. First description of Trypanosoma cruzi human infection in Esmeraldas province, Ecuador.

    Science.gov (United States)

    Guevara, Ángel; Moreira, Juan; Criollo, Hipatia; Vivero, Sandra; Racines, Marcia; Cevallos, Varsovia; Prandi, Rosanna; Caicedo, Cynthia; Robinzon, Francisco; Anselmi, Mariella

    2014-08-06

    Chagas disease was described in Ecuador in 1930 in the province of Guayas and thereafter in various provinces. Triatomine were reported in the province of Esmeraldas but no human infection has been described. Here we report the first evidence that the disease does exist in the province of Esmeraldas. In indigenous Awá communities located in the northwest jungle of the Esmeraldas province, 144 individuals were tested using ELISA and PCR for T.cruzi of which 5 (3.47%) were positive. Twenty eight triatomine were collected, 27 were Triatoma dispar and 1 Pastrongylus rufotuberculatus, T.cruzi was detected in 11 (42.3%) of 26 insects.

  15. 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.

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

    Science.gov (United States)

    Alroy, Karen A; Huang, Christine; Gilman, Robert H; Quispe-Machaca, Victor R; Marks, Morgan A; Ancca-Juarez, Jenny; Hillyard, Miranda; Verastegui, Manuela; Sanchez, Gerardo; Cabrera, Lilia; Vidal, Elisa; Billig, Erica M W; Cama, Vitaliano A; Náquira, César; Bern, Caryn; Levy, Michael Z

    2015-05-01

    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 Peru.

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

    Science.gov (United States)

    Alroy, Karen A.; Huang, Christine; Gilman, Robert H.; Quispe-Machaca, Victor R.; Marks, Morgan A.; Ancca-Juarez, Jenny; Hillyard, Miranda; Verastegui, Manuela; Sanchez, Gerardo; Cabrera, Lilia; Vidal, Elisa; Billig, Erica M. W.; Cama, Vitaliano A.; Náquira, César; Bern, Caryn; Levy, Michael Z.

    2015-01-01

    Background 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. Methodology 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 Peru. PMID:26000770

  18. Cxcl8b and Cxcr2 Regulate Neutrophil Migration through Bloodstream in Zebrafish

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    Constanza Zuñiga-Traslaviña

    2017-01-01

    Full Text Available Neutrophils play an essential role during an inflammatory response, which is dependent on their rapid recruitment from the bone marrow to the vasculature. However, there is no information about the molecular signals that regulate neutrophil entry to circulation during an inflammatory process in humans. This is mainly due to the lack of a suitable model of study that contains similar set of molecules and that allows in vivo analyses. In this study, we used the zebrafish to assess the role of Cxcl8a, Cxcl8b, and Cxcr2 in neutrophil migration to blood circulation after injury. Using Tg(BACmpx:GFPi114 transgenic embryos and two damage models (severe and mild, we developed in vivo lack of function assays. We found that the transcription levels of cxcl8a, cxcl8b, and cxcr2 were upregulated in the severe damage model. In contrast, only cxcr2 and cxcl8a mRNA levels were increased during mild damage. After knocking down Cxcl8a, neutrophil quantity decreased at the injury site, while Cxcl8b decreased neutrophils in circulation. When inhibiting Cxcr2, we observed a decrease in neutrophil entry to the bloodstream. In conclusion, we identified different functions for both Cxcl8 paralogues, being the Cxcl8b/Cxcr2 axis that regulates neutrophil entry to the bloodstream, while Cxcl8a/Cxcr2 regulates the migration to the affected area.

  19. Determination of germ tube, phospholipase, and proteinase production by bloodstream isolates of Candida albicans

    Directory of Open Access Journals (Sweden)

    Antonella Souza Mattei

    2013-06-01

    Full Text Available Introduction Candida albicans is a commensal and opportunistic agent that causes infection in immunocompromised individuals. Several attributes contribute to the virulence and pathogenicity of this yeast, including the production of germ tubes (GTs and extracellular hydrolytic enzymes, particularly phospholipase and proteinase. This study aimed to investigate GT production and phospholipase and proteinase activities in bloodstream isolates of C. albicans. Methods One hundred fifty-three C. albicans isolates were obtained from blood samples and analyzed for GT, phospholipase, and proteinase production. The assays were performed in duplicate in egg yolk medium containing bovine serum albumin and human serum. Results Detectable amounts of proteinase were produced by 97% of the isolates, and 78% of the isolates produced phospholipase. GTs were produced by 95% of the isolates. A majority of the isolates exhibited low levels of phospholipase production and high levels of proteinase production. Conclusions Bloodstream isolates of C. albicans produce virulence factors such as GT and hydrolytic enzymes that enable them to cause infection under favorable conditions.

  20. Outbreak of Serratia marcescens postsurgical bloodstream infection due to contaminated intravenous pain control fluids.

    Science.gov (United States)

    Chiang, Ping-Cherng; Wu, Tsu-Lan; Kuo, An-Jing; Huang, Yhu-Chering; Chung, Ting-Ying; Lin, Chun-Sui; Leu, Hsieh-Shong; Su, Lin-Hui

    2013-09-01

    Serratia marcescens is an important nosocomial pathogen causing significant outbreaks. Here we report an outbreak of bloodstream infection caused by S. marcescens at a 3500-bed hospital in Taiwan. The effective cooperative efforts of both laboratory personnel and infection control practitioners (ICPs) jointly contributed to the total control of the outbreak. A sudden increase in the isolation of S. marcescens from blood cultures was noted in the Clinical Microbiology Laboratory. The information was passed to the ICPs and an investigation was initiated. Pulsed-field gel electrophoresis was used to study the relationships among the isolates. Pulsotype A was identified in 43 (82.7%) of the 52 blood isolates studied. They were isolated from 52 patients distributed across 22 wards that were surveyed by seven ICPs. All patients had undergone surgery before the infection, and fentanyl-containing intravenous fluids were used for pain control in 43 of them. Isolates from 42 belonged to pulsotype A. Three S. marcescens isolates, all from fentanyl-containing fluids and demonstrating pulsotype A, were identified from 251 environmental cultures. All fentanyl-containing fluids that were in use were withdrawn and the outbreak was stopped. The outbreak of S. marcescens bloodstream infection apparently occurred through the use of fentanyl-containing fluids contaminated by a pulsotype A S. marcescens. Copyright © 2013 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  1. Procalcitonin levels in bloodstream infections caused by different sources and species of bacteria.

    Science.gov (United States)

    Yan, Sheng Tao; Sun, Li Chao; Jia, Hong Bing; Gao, Wen; Yang, Jian Ping; Zhang, Guo Qiang

    2017-04-01

    The aim of this study was to evaluate procalcitonin (PCT) diagnostic accuracy in discriminating gram-negative (GN) from gram-positive (GP) bloodstream infections and determining the relationship between PCT levels, infection sites, and pathogen types. Clinical and laboratory data were collected from patients with blood culture (BC)-positive sepsis between January 2014 and December 2015. PCT levels at different infection sites were compared, as was the presence of GN and GP bloodstream infection. A receiver operating characteristic (ROC) curve was generated to assess diagnostic accuracy. Of the 486 monomicrobial BCs, 254 (52.26%) were positive for GN bacteria (GNB), and 202 (42.18%) for GP bacteria (GPB). Median PCT levels were higher in BCs positive for GN (2.42ng/ml, IQR: 0.38-15.52) than in those positive for GPB (0.49ng/ml, IQR: 0.13-5.89) (PAcinetobacter baumanni/Burkholderia cepacia, Klebsiella pneumonia and Acinetobacter baumanni. PCT levels caused by GPB differed between Staphylococcus epidermidis/Staphylococcus aureus and Staphylococcus hominis/Staphylococcus haemolyticus, Enterococcus faecium and Enterococcus faecalis/S.hominis/S. haemolyticus. Among patients with known infection sites, there were statistical differences in PCT levels between abdominal infection and pneumonia/infective endocarditis, urinary tract infection and pneumonia/catheter-related infection/infective endocarditis. PCT can distinguish between GNB and GPB infection, as well as between different bacterial species and infection sites. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  2. KREX2 is not essential for either procyclic or bloodstream form Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Jason Carnes

    Full Text Available Most mitochondrial mRNAs in Trypanosoma brucei require RNA editing for maturation and translation. The edited RNAs primarily encode proteins of the oxidative phosphorylation system. These parasites undergo extensive changes in energy metabolism between the insect and bloodstream stages which are mirrored by alterations in RNA editing. Two U-specific exonucleases, KREX1 and KREX2, are both present in protein complexes (editosomes that catalyze RNA editing but the relative roles of each protein are not known.The requirement for KREX2 for RNA editing in vivo was assessed in both procyclic (insect and bloodstream form parasites by methods that use homologous recombination for gene elimination. These studies resulted in null mutant cells in which both alleles were eliminated. The viability of these cells demonstrates that KREX2 is not essential in either life cycle stage, despite certain defects in RNA editing in vivo. Furthermore, editosomes isolated from KREX2 null cells require KREX1 for in vitro U-specific exonuclease activity.KREX2 is a U-specific exonuclease that is dispensable for RNA editing in vivo in T. brucei BFs and PFs. This result suggests that the U deletion activity, which is required for RNA editing, is primarily mediated in vivo by KREX1 which is normally found associated with only one type of editosome. The retention of the KREX2 gene implies a non-essential role or a role that is essential in other life cycle stages or conditions.

  3. Coordinated Molecular Cross-Talk between Staphylococcus aureus, Endothelial Cells and Platelets in Bloodstream Infection

    Directory of Open Access Journals (Sweden)

    Carolina D. Garciarena

    2015-12-01

    Full Text Available Staphylococcus aureus is an opportunistic pathogen often carried asymptomatically on the human body. Upon entry to the otherwise sterile environment of the cardiovascular system, S. aureus can lead to serious complications resulting in organ failure and death. The success of S. aureus as a pathogen in the bloodstream is due to its ability to express a wide array of cell wall proteins on its surface that recognise host receptors, extracellular matrix proteins and plasma proteins. Endothelial cells and platelets are important cells in the cardiovascular system and are a major target of bloodstream infection. Endothelial cells form the inner lining of a blood vessel and provide an antithrombotic barrier between the vessel wall and blood. Platelets on the other hand travel throughout the cardiovascular system and respond by aggregating around the site of injury and initiating clot formation. Activation of either of these cells leads to functional dysregulation in the cardiovascular system. In this review, we will illustrate how S. aureus establish intimate interactions with both endothelial cells and platelets leading to cardiovascular dysregulation.

  4. Muscle Releases Alpha-Sarcoglycan Positive Extracellular Vesicles Carrying miRNAs in the Bloodstream.

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    Michele Guescini

    Full Text Available In the past few years, skeletal muscle has emerged as an important secretory organ producing soluble factors, called myokines, that exert either autocrine, paracrine or endocrine effects. Moreover, recent studies have shown that muscle releases microRNAs into the bloodstream in response to physical exercise. These microRNAs affect target cells, such as hormones and cytokines. The mechanisms underlying microRNA secretion are poorly characterized at present. Here, we investigated whether muscle tissue releases extracellular vesicles (EVs, which carry microRNAs in the bloodstream under physiological conditions such as physical exercise. Using density gradient separation of plasma from sedentary and physically fit young men we found EVs positive for TSG101 and alpha-sarcoglycan (SGCA, and enriched for miR-206. Cytometric analysis showed that the SGCA+ EVs account for 1-5% of the total and that 60-65% of these EVs were also positive for the exosomal marker CD81. Furthermore, the SGCA-immuno captured sub-population of EVs exhibited higher levels of the miR-206/miR16 ratio compared to total plasma EVs. Finally, a significant positive correlation was found between the aerobic fitness and muscle-specific miRNAs and EV miR-133b and -181a-5p were significantly up-regulated after acute exercise. Thus, our study proposes EVs as a novel means of muscle communication potentially involved in muscle remodeling and homeostasis.

  5. Utilización de Lepidium Peruvianum Maca, como medio de cultivo para el crecimiento de Trypanosoma Cruzi

    OpenAIRE

    Saldaña C, Charles; Córdova P, Ofelia; Vargas V¹, Franklin

    2006-01-01

    Por sus características nutritivas de alto valor, se ensayó la posible utilidad del Lepidium peruvianum maca, como un medio para cultivar Trypanosoma cruzi. Bajo condiciones experimentales se procedió a incubar epimastigotes de T. cruzi en cuatro medios de cultivo bifásicos diferentes, a base de Lepidium peruvianum maca, los cuales fueron comparados con el medio de cultivo BHI como control. La incorporación de maca como medio de cultivo permitió el crecimiento de Trypanosoma cruzi; se determi...

  6. 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

    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...

  7. Novel DNA coding regions and protein arginylation reveal unexplored T. cruzi proteome and PTMs

    DEFF Research Database (Denmark)

    de Oliveira, Gilberto Santos; Kawahara, Rebeca; Rosa-Fernandes, Livia

    2017-01-01

    Chagas disease, also known as American trypanosomiasis, is a neglected tropical disease caused by the Trypanosoma cruzi parasite. In order to develop diagnostic and therapeutic solutions, there has been an intense investigation on the parasite biology using omics technologies such as genomics...

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

    DEFF Research Database (Denmark)

    Hurtado-Guerrrero, Ramón; Pena Diaz, Javier; Montalvetti, Andrea

    2002-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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. 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.

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

    Czech Academy of Sciences Publication Activity Database

    Flegontova, Olga; Lukeš, Julius; Flegontov, Pavel

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Efficacy of some essential oils in mice infected with Trypanosoma cruzi

    African Journals Online (AJOL)

    Purpose: To evaluate the efficacy of orally administered Cymbopogon citratus, Zingiber officinale and Syzygium aromaticum essential oils (EOs) in mice infected with Trypanosoma cruzi. Methods: Three experiments were conducted with 48 Swiss mice each. The animals were inoculated with 2 x 106 metacyclic ...

  14. The Trypanosoma cruzi nucleolus: a morphometrical analysis of cultured epimastigotes in the exponential and stationary phases.

    Science.gov (United States)

    Nepomuceno-Mejía, Tomás; Lara-Martínez, Reyna; Cevallos, Ana María; López-Villaseñor, Imelda; Jiménez-García, Luis Felipe; Hernández, Roberto

    2010-12-01

    Our group is interested in rRNA and ribosome biogenesis in the parasitic protozoan Trypanosoma cruzi. Epimastigotes represent an extracellular replicative stage of T. cruzi and can be cultured in axenic media. The growth curve of epimastigotes allows assessment of potential differences in the nucleoli of cells undergoing growth-rate transitions. To establish cellular parameters for studying ribosome biogenesis in T. cruzi, a morphometric analysis of the nucleoli of cultured cells in the exponential and stationary phases was conducted. Electron micrograph-based measurements of nuclear sections from independent cells demonstrated that the nucleolar area is over twofold higher in exponentially growing cells, as compared with epimastigotes in the stationary phase. The granular component of the nucleoli of actively growing cells was the main structural element. Cycloheximide moderately reduced the apparent size of the nucleoli without an apparent disruption of their architecture. Our results provide a firm basis for the establishment of an experimental model to study the organization of the nucleolus during the growth and development of T. cruzi. © 2010 Federation of European Microbiological Societies Published by Blackwell Publishing Ltd. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    A.B. Araújo

    Full Text Available Trypanosoma cruzi, the causal agent of Chagas' Disease, is a widely spread protozoa in America. Blood transfusion is the secondly most important way of acquiring the infection. In blood banks, tests are performed to eliminate potentially infected blood. This study aimed to evaluate the positivity for T. cruzi in blood samples of donor's candidates in Southern Brazil. The study was based on a sampling containing all blood donors of Hemopel - a Pelotas City Blood Center, Rio Grande do Sul State, Brazil, from 2004 to 2005. Serological study was performed using ELISA Chagatest. Sampling containing values ± 20% cut off were evaluated using ELISA Chagatek, ELISA Alka/Adaltis, IHA Chagatest and IIF Imunocruzi. TESA-Blot was used as a confirmatory procedure in situations where blood samples showed conflicting results. From 4,482 samples collected in 2004 and 2005, the reactivity for anti-T. cruzi was 0.96% (43. Among those, 21 cases (0.47% were confirmed as positive - most of them were female, with low school level and averaging 47.2% years old. Interestingly, the blood donors are not aware of being contaminated and this fact makes it difficult for controlling the disease. Chagas' Disease was one of the main reasons for discarding blood bags through serological control in Southern Brazil. Sampling reactivity showed variation among the different techniques used for anti-T. cruzi research. In order to obtaining more secure and conclusive results, more than one diagnostic technique must be used.

  16. 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.

  17. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Czech Academy of Sciences Publication Activity Database

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

    2011-01-01

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

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

    Science.gov (United States)

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

    2016-07-01

    Chagas disease is a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In Ecuador, Triatoma dimidiata and Rhodnius ecuadoriensis are the main vector species, responsible for over half of the cases of T. cruzi infection in the country. T. dimidiata is believed to have been introduced in Ecuador during colonial times, and its elimination from the country is thus believed to be feasible. We investigated here the molecular ecology of T. dimidiata and T. cruzi in costal Ecuador to further guide control efforts. Analysis of the Internal Transcribed Spacer 2 (ITS-2) of 23 specimens from Progreso, Guayas, unambiguously supported the likely importation of T. dimidiata from Central America to Ecuador. The observation of a very high parasite infection rate (54%) and frequent feeding on humans (3/5) confirmed a continued risk of transmission to humans. All genotyped parasites corresponded to TcI DTU and Trypanosoma rangeli was not detected in T. dimidiata. TcI subgroups corresponded to TcIa (25%), and mixed infections with TcIa and TcId (75%). Further studies should help clarify T. cruzi genetic structure in the country, and the possible impact of the introduction of T. dimidiata on the circulating parasite strains. The elevated risk posed by this species warrants continuing efforts for its control, but its apparent mobility between peridomestic and domestic habitats may favor reinfestation following insecticide spraying. Copyright © 2016 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  3. The Prevalence of Chagas Heart Disease in a Central Bolivian Community Endemic for Trypanosoma Cruzi

    Science.gov (United States)

    Yager, Jessica E.; Lozano Beltran, Daniel F.; Torrico, Faustino; Gilman, Robert H.; Bern, Caryn

    2015-01-01

    Background Though the incidence of new Trypanosoma cruzi infections has decreased significantly in endemic regions in the Americas, medical professionals continue to encounter a high burden of resulting Chagas disease among infected adults. The current prevalence of Chagas heart disease in a community setting is not known; nor is it known how recent insecticide vector control measures may have impacted the progression of cardiac disease in an infected population. Objectives and Methods Nested within a community serosurvey in rural and periurban communities in central Bolivia, we performed a cross-sectional cardiac substudy to evaluate adults for historical, clinical, and electrocardiographic evidence of cardiac disease. All adults between the ages of 20 and 60 years old with T. cruzi infection and those with a clinical history, physical exam, or ECG consistent with cardiac abnormalities were also scheduled for echocardiography. Results and conclusions Of the 604 cardiac substudy participants with definitive serology results, 183 were seropositive for infection with T. cruzi (30.3%). Participants who were seropositive for T. cruzi infection were more likely to have conduction system defects (1.6% versus 0 for complete right bundle branch block and 10.4% versus 1.9% for any bundle branch block; p=0.008 and p<0.001, respectively). However, there was no statistically significant difference in the prevalence of bradycardia among seropositive versus seronegative participants. Echocardiogram findings were not consistent with a high burden of Chagas cardiomyopathy: valvulopathies were the most common abnormality, and few participants were found to have low ejection fraction or left ventricular dilatation. No participants had significant heart failure. Though almost one third of adults in the community were seropositive for T. cruzi infection, few had evidence of Chagas heart disease. PMID:26407509

  4. Association of Trypanosoma cruzi infection with risk factors and electrocardiographic abnormalities in northeast Mexico

    Science.gov (United States)

    2014-01-01

    Background American trypanosomiasis is a major disease and public health issue, caused by the protozoan parasite Trypanosoma cruzi. The prevalence of T. cruzi has not been fully documented, and there are few reports of this issue in Nuevo Leon. The aim of this study was to update the seroprevalence rate of T. cruzi infection, including an epidemiological analysis of the risk factors associated with this infection and an electrocardiographic (ECG) evaluation of those infected. Methods Sera from 2,688 individuals from 10 municipalities in the state of Nuevo Leon, Mexico, were evaluated using an enzyme-linked immunosorbent assay and an indirect hemagglutination assay. An ECG case–control study was performed in subjects seropositive for T. cruzi and the results were matched by sex and age to seronegative residents of the same localities. A univariate analysis with χ2 and Fisher’s exact tests was used to determine the association between seropositivity and age (years), sex, and ECG changes. A multivariate analysis was then performed to calculate the odd ratios between T. cruzi seropositivity and the risk factors. Results The seropositive rate was 1.93% (52/2,688). In the ECG study, 22.85% (8/35) of the infected individuals exhibited ECG abnormalities. Triatoma gerstaeckeri was the only vector reported. The main risk factors were ceiling construction material (P ≤ 0.0024), domestic animals (P ≤ 0.0001), and living in rural municipalities (P ≤ 0.0025). Conclusions These findings demonstrate a 10-fold higher prevalence of Chagas disease than previously reported (0.2%), which implies a serious public health threat in northeastern Mexico. The epidemiological profile established in this study differs from that found in the rest of Mexico, where human populations live in close proximity to domiciliary triatomines. PMID:24580840

  5. Macrophage Migration Inhibitory Factor Contributes to Host Defense against Acute Trypanosoma cruzi Infection

    Science.gov (United States)

    Reyes, José L.; Terrazas, Luis I.; Espinoza, Bertha; Cruz-Robles, David; Soto, Virgilia; Rivera-Montoya, Irma; Gómez-García, Lorena; Snider, Heidi; Satoskar, Abhay R.; Rodríguez-Sosa, Miriam

    2006-01-01

    Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that is involved in the host defense against several pathogens. Here we used MIF−/− mice to determine the role of endogenous MIF in the regulation of the host immune response against Trypanosoma cruzi infection. MIF−/− mice displayed high levels of blood and tissue parasitemia, developed severe heart and skeletal muscle immunopathology, and succumbed to T. cruzi infection faster than MIF+/+ mice. The enhanced susceptibility of MIF−/− mice to T. cruzi was associated with reduced levels of proinflammatory cytokines, such as tumor necrosis factor alpha, interleukin-12 (IL-12), IL-18, gamma interferon (IFN-γ), and IL-1β, in their sera and reduced production of IL-12, IFN-γ, and IL-4 by spleen cells during the early phase of infection. At all time points, antigen-stimulated splenocytes from MIF+/+ and MIF−/− mice produced comparable levels of IL-10. MIF−/− mice also produced significantly less Th1-associated antigen-specific immunoglobulin G2a (IgG2a) throughout the infection, but both groups produced comparable levels of Th2-associated IgG1. Lastly, inflamed hearts from T. cruzi-infected MIF−/− mice expressed increased transcripts for IFN-γ, but fewer for IL-12 p35, IL-12 p40, IL-23, and inducible nitric oxide synthase, compared to MIF+/+ mice. Taken together, our findings show that MIF plays a role in controlling acute T. cruzi infection. PMID:16714544

  6. Parasitic loads in tissues of mice infected with Trypanosoma cruzi and treated with AmBisome.

    Directory of Open Access Journals (Sweden)

    Sabrina Cencig

    2011-06-01

    Full Text Available BACKGROUND: Chagas disease is one of the most important public health problems and a leading cause of cardiac failure in Latin America. The currently available drugs to treat T. cruzi infection (benznidazole and nifurtimox are effective in humans when administered during months. AmBisome (liposomal amphotericin B, already shown efficient after administration for some days in human and experimental infection with Leishmania, has been scarcely studied in T. cruzi infection. AIMS: This work investigates the effect of AmBisome treatment, administered in 6 intraperitoneal injections at various times during acute and/or chronic phases of mouse T. cruzi infection, comparing survival rates and parasitic loads in several tissues. METHODOLOGY: Quantitative PCR was used to determine parasitic DNA amounts in tissues. Immunosuppressive treatment with cyclophosphamide was used to investigate residual infection in tissues. FINDINGS: Administration of AmBisome during the acute phase of infection prevented mice from fatal issue. Parasitaemias (microscopic examination were reduced in acute phase and undetectable in chronic infection. Quantitative PCR analyses showed significant parasite load reductions in heart, liver, spleen, skeletal muscle and adipose tissues in acute as well as in chronic infection. An earlier administration of AmBisome (one day after parasite inoculation had a better effect in reducing parasite loads in spleen and liver, whereas repetition of treatment in chronic phase enhanced the parasite load reduction in heart and liver. However, whatever the treatment schedule, cyclophosphamide injections boosted infection to parasite amounts comparable to those observed in acutely infected and untreated mice. CONCLUSIONS: Though AmBisome treatment fails to completely cure mice from T. cruzi infection, it impedes mortality and reduces significantly the parasitic loads in most tissues. Such a beneficial effect, obtained by administrating it over a short

  7. Assessing anti-T. cruzi candidates in vitro for sterile cidality

    Directory of Open Access Journals (Sweden)

    Monica Cal

    2016-12-01

    Full Text Available Total clearance of the T. cruzi infection – referred to herein as “sterile cure” – seems to be a critical prerequisite for new drug candidates for Chagas disease, ensuring long-term beneficial effects for patients in the chronic indeterminate stage. This requirement is notably supported by the recent findings of clinical studies involving posaconazole and fosravuconazole, where the majority of patients treated eventually relapsed after an apparent clearance of parasitaemia at the end of treatment. We have adapted an in vitro system to predict the ability of a compound to deliver sterile cure. It relies on mouse peritoneal macrophages as host cells for Trypanosoma cruzi amastigotes. The macrophages do not proliferate, allowing for long-term testing and wash-out experiments. Giemsa staining followed by microscopy provides a highly sensitive and specific tool to quantify the numbers of infected host cells. Combining macrophages as host cells and Giemsa staining as the read-out, we demonstrate that posaconazole and other CYP51 inhibitors are unable to achieve complete clearance of an established T. cruzi infection in vitro in spite of the fact that these compounds are active at significantly lower concentrations than the reference drugs benznidazole and nifurtimox. Indeed, a few macrophages remained infected after 96 h of drug incubation in the presence of CYP51 inhibitors–albeit at a very low parasite load. These residual T. cruzi amastigotes were shown to be viable and infective, as demonstrated by wash-out experiments. We advocate characterizing any new anti-T. cruzi early stage candidates for sterile cidality early in the discovery cascade, as a surrogate for delivery of sterile cure in vivo.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Patients with Central Lines — What You Need to Know to Avoid a Bloodstream Infection

    Centers for Disease Control (CDC) Podcasts

    2011-03-01

    This podcast is based on the March, 2011 CDC Vital Signs report which indicates bloodstream infections in patients with central lines are largely preventable when healthcare providers use CDC-recommended infection control steps.  Created: 3/1/2011 by Centers for Disease Control and Prevention (CDC).   Date Released: 3/1/2011.

  10. Community-Onset Bloodstream Infection during the ‘After Hours’ Is not Associated with an increased Risk for Death

    Directory of Open Access Journals (Sweden)

    Kevin B Laupland

    2012-01-01

    Full Text Available BACKGROUND/OBJECTIVE: Patients admitted to hospital during the ‘after hours’ (weekends and evenings may be at increased risk for adverse outcome. The objective of the present study was to assess whether community-onset bloodstream infections presenting in the after hours are associated with death.

  11. Taurolidine-citrate-heparin lock reduces catheter-related bloodstream infections in intestinal failure patients dependent on home parenteral support

    DEFF Research Database (Denmark)

    Tribler, Siri; Brandt, Christopher F.; Petersen, Anne H.

    2017-01-01

    Background: In patients with intestinal failure who are receiving home parenteral support (HPS), catheter-related bloodstream infections (CRBSIs) inflict health impairment and high costs.Objective: This study investigates the efficacy and safety of the antimicrobial catheter lock solution, taurol...

  12. Adaptations in the glucose metabolism of procyclic Trypanosoma brucei isolates from Tsetse flies and during differentiation of bloodstream forms.

    NARCIS (Netherlands)

    van Grinsven, K.W.A.; van den Abbeele, J.; van den Bossche, P.; van Hellemond, J.J.; Tielens, A.G.M.

    2009-01-01

    Procyclic forms of Trypanosoma brucei isolated from the midguts of infected tsetse flies, or freshly transformed from a strain that is close to field isolates, do not use a complete Krebs cycle. Furthermore, short stumpy bloodstream forms produce acetate and are apparently metabolically preadapted

  13. Clinical and Laboratory Characteristics of Patients with Nontuberculous Mycobacterium Bloodstream Infection in a Tertiary Referral Hospital in Beijing, China

    Directory of Open Access Journals (Sweden)

    Sai-Nan Bian

    2016-01-01

    Conclusions: We reported all cases in our hospital diagnosed with bloodstream NTM infection that was rarely reported. In this group of patients, patients usually had a high fever and could have multiple organ involvements. All patients with poor prognosis had underlying diseases.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Susceptibilidad in vitro a hexadecilfosfocolina (miltefosina, nifurtimox y benznidazole de cepas de Trypanosoma cruzi aisladas en Santander, Colombia

    Directory of Open Access Journals (Sweden)

    Patricia Escobar

    2009-09-01

    Conclusiones. Los resultados obtenidos de la actividad in vitro de miltefosina y de los medicamentos de referencia contra aislamientos de T. cruzi son satisfactorios y serán considerados en estudios posteriores in vivo.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. Taurolidine lock is superior to heparin lock in the prevention of catheter related bloodstream infections and occlusions.

    Directory of Open Access Journals (Sweden)

    Evelyn D Olthof

    Full Text Available Patients on home parenteral nutrition (HPN are at risk for catheter-related complications; mainly infections and occlusions. We have previously shown in HPN patients presenting with catheter sepsis that catheter locking with taurolidine dramatically reduced re-infections when compared with heparin. Our HPN population therefore switched from heparin to taurolidine in 2008. The aim of the present study was to compare long-term effects of this catheter lock strategy on the occurrence of catheter-related bloodstream infections and occlusions in HPN patients.Data of catheter-related complications were retrospectively collected from 212 patients who received HPN between January 2000 and November 2011, comprising 545 and 200 catheters during catheter lock therapy with heparin and taurolidine, respectively. We evaluated catheter-related bloodstream infection and occlusion incidence rates using Poisson-normal regression analysis. Incidence rate ratios were calculated by dividing incidence rates of heparin by those of taurolidine, adjusting for underlying disease, use of anticoagulants or immune suppressives, frequency of HPN/fluid administration, composition of infusion fluids, and duration of HPN/fluid use before catheter creation.Bloodstream infection incidence rates were 1.1/year for heparin and 0.2/year for taurolidine locked catheters. Occlusion incidence rates were 0.2/year for heparin and 0.1/year for taurolidine locked catheters. Adjusted incidence ratios of heparin compared to taurolidine were 5.9 (95% confidence interval, 3.9-8.7 for bloodstream infections and 1.9 (95% confidence interval, 1.1-3.1 for occlusions.Given that no other procedural changes than the catheter lock strategy were implemented during the observation period, these data strongly suggest that taurolidine decreases catheter-related bloodstream infections and occlusions in HPN patients compared with heparin.

  18. Positive deviance as a strategy to prevent and control bloodstream infections in intensive care

    Directory of Open Access Journals (Sweden)

    Francimar Tinoco de Oliveira

    Full Text Available Abstract OBJECTIVE To describe the application of positive deviance as a strategy to prevent and control bloodstream infections. METHOD An intervention study with nursing and medical team members working in an intensive care unit in a university hospital, between June and December 2014. The four steps of the positive defiance methodology were applied: to define, to determine, to discover and to design. RESULTS In 90 days, 188 actions were observed, of these, 36.70% (n=69 were related to catheter dressing. In 81.15% (n=56 of these dressings, the professionals most adhered to the use of flexible sterile cotton-tipped swabs to perform antisepsis at catheter entry sites and fixation dressing. CONCLUSION Positive deviance contributed to the implementation of proposals to improve work processes and team development related to problems identified in central venous catheter care.

  19. [Evaluation of practices for the prevention and control of bloodstream infections in a government hospital].

    Science.gov (United States)

    Jardim, Jaquelline Maria; Lacerda, Rúbia Aparecida; Soares, Naury de Jesus Danzi; Nunes, Bruna Kosar

    2013-02-01

    The aim of this study was to observe clinical procedures in order to evaluate the practices used for the control and prevention of bloodstream infections associated with short-term central venous catheters (BSI-ACVC). The study data came from 5877 assessments distributed among selected practices. The results revealed the following adherence rates among the practices selected: 91.6% for recording the indication and permanence time of the CVC, 51.5% for adhering to the care and maintenance of the dressing at the CVC insertion site and its devices, 10.7% for hand hygiene practices while performing procedures related to the CVC, and 0.0% for the practices related to the insertion of the central venous catheter (CVC). The results demonstrate the need for further elaboration of strategies that ensure sustainable compliance practices for prevention and control BSI-ACVC in the institution being assessed.

  20. In vitro interactions between different beta-lactam antibiotics and fosfomycin against bloodstream isolates of enterococci.

    Science.gov (United States)

    Pestel, M; Martin, E; Aucouturier, C; Lemeland, J F; Caron, F

    1995-01-01

    The effects of 16 different beta-lactam-fosfomycin combinations against 50 bloodstream enterococci were compared by a disk diffusion technique. Cefotaxime exhibited the best interaction. By checkerboard studies, the cefotaxime-fosfomycin combination provided a synergistic bacteriostatic effect against 45 of the 50 isolates (MIC of cefotaxime at which 90% of the isolates were inhibited, >2,048 micrograms/ml; MIC of fosfomycin at which 90% of the isolates were inhibited, 128 micrograms/ml; mean of fractional inhibitory concentration indexes, 0.195). By killing curves, cefotaxime (at 64 micrograms/ml) combined with fosfomycin (at > or = 64 micrograms/ml) was bactericidal against 6 of 10 strains tested. PMID:8619593

  1. APSIC guide for prevention of Central Line Associated Bloodstream Infections (CLABSI

    Directory of Open Access Journals (Sweden)

    Moi Lin Ling

    2016-05-01

    Full Text Available Abstract This document is an executive summary of the APSIC Guide for Prevention of Central Line Associated Bloodstream Infections (CLABSI. It describes key evidence-based care components of the Central Line Insertion and Maintenance Bundles and its implementation using the quality improvement methodology, namely the Plan-Do-Study-Act (PDSA methodology involving multidisciplinary process and stakeholders. Monitoring of improvement over time with timely feedback to stakeholders is a key component to ensure the success of implementing best practices. A surveillance program is recommended to monitor outcomes and adherence to evidence-based central line insertion and maintenance practices (compliance rate and identify quality improvement opportunities and strategically targeting interventions for the reduction of CLABSI.

  2. 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.

    2010-01-01

    Abstract 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

  3. Use of Full-Length Recombinant Calflagin and Its C Fragment for Improvement of Diagnosis of Trypanosoma cruzi Infection†

    Science.gov (United States)

    Marcipar, Iván S.; Roodveldt, Cintia; Corradi, Gerardo; Cabeza, María L.; Brito, Maria Edileuza F.; Winter, Lucile M. Floeter; Marcipar, Alberto J.; Silber, Ariel M.

    2005-01-01

    Serological diagnosis of Trypanosoma cruzi infection is hampered by issues related to test specificity due to the cross-reactivity of most antigens with proteins of related parasites such as Leishmania spp. The recombinant calflagins are considered relevant antigens for the diagnosis of infection by Trypanosoma cruzi. In the present work, we describe two genes coding for putative calflagins in Leishmania major with the N-terminal moieties presenting high similarity with T. cruzi genes. This fact raised questions about their role in some cross-recognition of this antigen by sera from Leishmania spp.-infected individuals. The complete T. cruzi calflagin and two fragments of the protein, consisting of 146 amino acids of the N-terminal and 65 amino acids of the C-terminal regions, were expressed and evaluated against a panel of sera, which included well-characterized samples from T. cruzi, and Leishmania-infected patients. We were able to show that sera from Leishmania (Viannia) braziliensis-infected individuals recognized the recombinant full-length calflagin. Both the N-terminal and the complete protein presented the same high sensitivity (98.5% of sera from T. cruzi-infected patients was detected) but different specificities (94% and 98%, respectively, when evaluated against sera from people not infected by T. cruzi, including 15 sera from people infected with L. braziliensis). The C-terminal fragment presented low sensitivity (70%) but 100% specificity. We propose the use of these antigens in two sequential assays to optimize the serological diagnosis of T. cruzi infection in humans in geographic areas where Leishmania spp. infection is coendemic. PMID:16272476

  4. The early implementation of Trypanosoma cruzi antibody screening of donors and donations within England: preempting a problem.

    Science.gov (United States)

    Kitchen, Alan D; Hewitt, Patricia E; Chiodini, Peter L

    2012-09-01

    Trypanosoma cruzi is a parasitic infection endemic in Central and Southern America, but is spreading into nonendemic countries with migration of infected individuals from endemic countries. The parasite is transmitted by transfusion or transplantation and donation screening is performed routinely in endemic countries to prevent transmission. In situations where migrants from endemic countries have settled in nonendemic countries and present as donors (blood or other cellular products), intervention is required to prevent transfusion or transplantation transmission. A screening program for T. cruzi was developed and has been used successfully for over 10 years that includes donor selection and donation screening. Donor selection criteria to identify specific risk of T. cruzi infection were developed together with laboratory screening of donations for T. cruzi antibodies and the subsequent confirmation of screen reactivity. Since the introduction of T. cruzi screening in England in 1998, a total of 38,585 donors and donations have been screened for T. cruzi antibodies, of which 223 were repeat reactive on screening and referred for confirmation: 206 confirmed negative, 14 inconclusive, and three positive. Since the move in 2005 from donor qualification to donation release testing, 15,536 donations were collected and screened, of which 15,499 (99.8%) were T. cruzi antibody negative and released to inventory. An effective program to minimize risk of the transmission of T. cruzi infection via donations has been developed and implemented. Not only does the program minimize risk of transmission, it also minimizes the cumulative, and needless, loss of donors and donations that would ensue if permanent donor deferral alone was adopted. © 2012 American Association of Blood Banks.

  5. Hosts and vectors of Trypanosoma cruzi discrete typing units in the Chagas disease endemic region of the Paraguayan Chaco

    OpenAIRE

    ACOSTA, NIDIA; L?PEZ, ELSA; LEWIS, MICHAEL D.; LLEWELLYN, MARTIN S.; G?MEZ, ANA; ROM?N, FABIOLA; MILES, MICHAEL A.; YEO, MATTHEW

    2017-01-01

    SUMMARY Active Trypanosoma cruzi transmission persists in the Gran Chaco region, which is considered hyperendemic for Chagas disease. Understanding domestic and sylvatic transmission cycles and therefore the relationship between vectors and mammalian hosts is crucial to designing and implementing improved effective control strategies. Here we describe the species of triatomine vectors and the sylvatic mammal reservoirs of T. cruzi, in different localities of the Paraguayan and Bolivian Chaco....

  6. Should we use closed or open infusion containers for prevention of bloodstream infections?

    Science.gov (United States)

    Rangel-Frausto, Manuel S; Higuera-Ramirez, Francisco; Martinez-Soto, Jose; Rosenthal, Victor D

    2010-02-02

    Hospitalized patients in critical care settings are at risk for bloodstream infections (BSI). Most BSIs originate from a central line (CL), and they increase length of stay, cost, and mortality. Open infusion containers may increase the risk of contamination and administration-related (CLAB) because they allow the entry of air into the system, thereby also providing an opportunity for microbial entry. Closed infusion containers were designed to overcome this flaw. However, open infusion containers are still widely used throughout the world.The objective of the study was to determine the effect of switching from open (glass, burettes, and semi-rigid) infusion containers to closed, fully collapsible, plastic infusion containers (Viaflex) on the rate and time to onset of central line-associated bloodstream infections CLABs. An open label, prospective cohort, active healthcare-associated infection surveillance, sequential study was conducted in four ICUs in Mexico. Centers for Disease Control National Nosocomial Infections Surveillance Systems definitions were used to define device-associated infections. A total of 1,096 adult patients who had a central line in place for >24 hours were enrolled. The CLAB rate was significantly higher during the open versus the closed container period (16.1 versus 3.2 CLAB/1000 central line days; RR = 0.20, 95% CI = 0.11-0.36, P container period (1.4% Days 2-4 to 0.5% Days 8-10), but increased in the open container period (4.9% Days 2-4 to 5.4% Days 8-10). The chance of acquiring a CLAB was significantly decreased (81%) in the closed container period (Cox proportional hazard ratio 0.19, P container period (23.4% versus 16.1%; RR = 0.69, 95% CI = 0.54-0.88, P containers significantly reduced CLAB rate, the probability of acquiring CLAB, and mortality.

  7. Bloodstream-To-Eye Infections Are Facilitated by Outer Blood-Retinal Barrier Dysfunction.

    Directory of Open Access Journals (Sweden)

    Phillip S Coburn

    Full Text Available The blood-retinal barrier (BRB functions to maintain the immune privilege of the eye, which is necessary for normal vision. The outer BRB is formed by tightly-associated retinal pigment epithelial (RPE cells which limit transport within the retinal environment, maintaining retinal function and viability. Retinal microvascular complications and RPE dysfunction resulting from diabetes and diabetic retinopathy cause permeability changes in the BRB that compromise barrier function. Diabetes is the major predisposing condition underlying endogenous bacterial endophthalmitis (EBE, a blinding intraocular infection resulting from bacterial invasion of the eye from the bloodstream. However, significant numbers of EBE cases occur in non-diabetics. In this work, we hypothesized that dysfunction of the outer BRB may be associated with EBE development. To disrupt the RPE component of the outer BRB in vivo, sodium iodate (NaIO3 was administered to C57BL/6J mice. NaIO3-treated and untreated mice were intravenously injected with 108 colony forming units (cfu of Staphylococcus aureus or Klebsiella pneumoniae. At 4 and 6 days postinfection, EBE was observed in NaIO3-treated mice after infection with K. pneumoniae and S. aureus, although the incidence was higher following S. aureus infection. Invasion of the eye was observed in control mice following S. aureus infection, but not in control mice following K. pneumoniae infection. Immunohistochemistry and FITC-dextran conjugate transmigration assays of human RPE barriers after infection with an exoprotein-deficient agr/sar mutant of S. aureus suggested that S. aureus exoproteins may be required for the loss of the tight junction protein, ZO-1, and for permeability of this in vitro barrier. Our results support the clinical findings that for both pathogens, complications which result in BRB permeability increase the likelihood of bacterial transmigration from the bloodstream into the eye. For S. aureus, however, BRB

  8. How Does the VSG Coat of Bloodstream Form African Trypanosomes Interact with External Proteins?

    Directory of Open Access Journals (Sweden)

    Angela Schwede

    2015-12-01

    Full Text Available Variations on the statement "the variant surface glycoprotein (VSG coat that covers the external face of the mammalian bloodstream form of Trypanosoma brucei acts a physical barrier" appear regularly in research articles and reviews. The concept of the impenetrable VSG coat is an attractive one, as it provides a clear model for understanding how a trypanosome population persists; each successive VSG protects the plasma membrane and is immunologically distinct from previous VSGs. What is the evidence that the VSG coat is an impenetrable barrier, and how do antibodies and other extracellular proteins interact with it? In this review, the nature of the extracellular surface of the bloodstream form trypanosome is described, and past experiments that investigated binding of antibodies and lectins to trypanosomes are analysed using knowledge of VSG sequence and structure that was unavailable when the experiments were performed. Epitopes for some VSG monoclonal antibodies are mapped as far as possible from previous experimental data, onto models of VSG structures. The binding of lectins to some, but not to other, VSGs is revisited with more recent knowledge of the location and nature of N-linked oligosaccharides. The conclusions are: (i Much of the variation observed in earlier experiments can be explained by the identity of the individual VSGs. (ii Much of an individual VSG is accessible to antibodies, and the barrier that prevents access to the cell surface is probably at the base of the VSG N-terminal domain, approximately 5 nm from the plasma membrane. This second conclusion highlights a gap in our understanding of how the VSG coat works, as several plasma membrane proteins with large extracellular domains are very unlikely to be hidden from host antibodies by VSG.

  9. Nosocomial Bloodstream Infections in Brazilian Pediatric Patients: Microbiology, Epidemiology, and Clinical Features

    Science.gov (United States)

    Pereira, Carlos Alberto Pires; Marra, Alexandre R.; Camargo, Luis Fernando Aranha; Pignatari, Antônio Carlos Campos; Sukiennik, Teresa; Behar, Paulo Renato Petersen; Medeiros, Eduardo Alexandrino Servolo; Ribeiro, Julival; Girão, Evelyne; Correa, Luci; Guerra, Carla; Carneiro, Irna; Brites, Carlos; Reis, Marise; de Souza, Marta Antunes; Tranchesi, Regina; Barata, Cristina U.; Edmond, Michael B.

    2013-01-01

    Background Nosocomial bloodstream infections (nBSIs) are an important cause of morbidity and mortality and are the most frequent type of nosocomial infection in pediatric patients. Methods We identified the predominant pathogens and antimicrobial susceptibilities of nosocomial bloodstream isolates in pediatric patients (≤16 years of age) in the Brazilian Prospective Surveillance for nBSIs at 16 hospitals from 12 June 2007 to 31 March 2010 (Br SCOPE project). Results In our study a total of 2,563 cases of nBSI were reported by hospitals participating in the Br SCOPE project. Among these, 342 clinically significant episodes of BSI were identified in pediatric patients (≤16 years of age). Ninety-six percent of BSIs were monomicrobial. Gram-negative organisms caused 49.0% of these BSIs, Gram-positive organisms caused 42.6%, and fungi caused 8.4%. The most common pathogens were Coagulase-negative staphylococci (CoNS) (21.3%), Klebsiella spp. (15.7%), Staphylococcus aureus (10.6%), and Acinetobacter spp. (9.2%). The crude mortality was 21.6% (74 of 342). Forty-five percent of nBSIs occurred in a pediatric or neonatal intensive-care unit (ICU). The most frequent underlying conditions were malignancy, in 95 patients (27.8%). Among the potential factors predisposing patients to BSI, central venous catheters were the most frequent (66.4%). Methicillin resistance was detected in 37 S. aureus isolates (27.1%). Of the Klebsiella spp. isolates, 43.2% were resistant to ceftriaxone. Of the Acinetobacter spp. and Pseudomonas aeruginosa isolates, 42.9% and 21.4%, respectively, were resistant to imipenem. Conclusions In our multicenter study, we found a high mortality and a large proportion of gram-negative bacilli with elevated levels of resistance in pediatric patients. PMID:23861860

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

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    Fred Luciano Neves Santos

    Full Text Available 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.

  11. The effectiveness of riboflavin and ultraviolet light pathogen reduction technology in eliminating Trypanosoma cruzi from leukoreduced whole blood.

    Science.gov (United States)

    Jimenez-Marco, Teresa; Cancino-Faure, Beatriz; Girona-Llobera, Enrique; Alcover, M Magdalena; Riera, Cristina; Fisa, Roser

    2017-06-01

    The parasitic Chagas disease is caused by the protozoan Trypanosoma cruzi, which is mainly transmitted by insect vectors. Other infection routes, both in endemic and in nonendemic areas, include organ and marrow transplantation, congenital transmission, and blood transfusion. Asymptomatic chronic chagasic individuals may have a low and transient parasitemia in peripheral blood and, consequently, they can unknowingly transmit the disease via blood transfusion. Riboflavin and ultraviolet (UV) light pathogen reduction is a method to reduce pathogen transfusion transmission risk based on damage to the pathogen nucleic acids. In this study, we tested the effectiveness of this technology for the elimination of T. cruzi parasites in artificially contaminated whole blood units (WBUs) and thus for decreasing the risk of T. cruzi transfusion transmission. The contaminated WBUs were leukoreduced by filtration and treated with riboflavin and UV light. The level of pathogen reduction was quantified by a real-time polymerase chain reaction (qPCR) and a real-time reverse transcription-polymerase chain reaction (RT-qPCR) as a viability assay. The RNA (cDNA) quantification of the parasites showed a more than 99% reduction of viable T. cruzi parasites after leukoreduction and a complete reduction (100%) after the riboflavin and UV light treatment. Riboflavin and UV light treatment and leukoreduction used in conjunction appears to eliminate significant amounts of viable T. cruzi in whole blood. Both strategies could complement other blood bank measures already implemented to prevent the transmission of T. cruzi via blood transfusion. © 2017 AABB.

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

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    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.

  13. Estudo parasitológico e anátomo-patológico da fase aguda da doença de Chagas em cães inoculados com duas diferentes cepas do Trypanosoma cruzi

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    Maria Alice Pedreira de Castro

    1985-12-01

    Full Text Available Cães jovens foram infectados com as cepas Y e CL do T. cruzi usando-se como inóculos 107 formas sangüíneas inoculadaspor via intraperitoneal e 2 x 10³ tripomastigotas metacíclicos obtidos do inseto vetor e inoculadospor via conjuntival. As cepas Ye CL induziram nos cães curvas deparasitemia totalmente distintas, confirmando dados parasitológicos obtidos em camundongos e coelhos. Com a cepa CL a parasitemia, com ambos os inóculos, foi gradualmente ascencional ao passo que com Y a parasitemia foi extremamente baixa, irregular e, com freqüência, subpatente. Com ambas as cepas o parasitismo e as lesões predominaram no miocárdio. Entretanto, com a cepa Y a miocardite foi sempre intensa desde as fases mais precoces da infecção, ao passo que com a cepa CL o processo inflamatório tomou-se acentuado somente a partir do 20.° dia. Freqüentemente a intensidade da miocardite observada em alguns animais não guardava relação com a parasitemia; em alguns cães com parasitemia subpatente, nos quais a infecção só foi diagnosticada pelo xenodiagnóstico, a intensidade da miocardite foi comparável àquela observada nos animais com parasitemia patente. Idêntica correlação também não foi assinalada em relação ao parasitismo tissular. Esses achados sugerem a participação de mecanismo imunológicos na gênese das lesões, ainda na fase aguda da infecção.Young dogs were inoculated with T. cruzi Y and CL strains either by intraperitoneal route with 107 blood forms or by ocular route with 2 x 10³ vector-derived trypomastigotes. With both inocula the patterns of parasitemia were significantly different, confirming data previously obtained in experimentally infected mice and rabbits. CL strain induced a gradual ascencional parasitemia whereas with Y the parasitemia was either subpatent or the number of parasites was very low, rapidly declining. Although myocarditis was present in most animals regardless of the strain used, the

  14. New insights into Trypanosoma cruzi evolution, genotyping and molecular diagnostics from satellite DNA sequence analysis.

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    Juan C Ramírez

    2017-12-01

    Full Text Available Trypanosoma cruzi has been subdivided into seven Discrete Typing Units (DTUs, TcI-TcVI and Tcbat. Two major evolutionary models have been proposed to explain the origin of hybrid lineages, but while it is widely accepted that TcV and TcVI are the result of genetic exchange between TcII and TcIII strains, the origin of TcIII and TcIV is still a matter of debate. T. cruzi satellite DNA (SatDNA, comprised of 195 bp units organized in tandem repeats, from both TcV and TcVI stocks were found to have SatDNA copies type TcI and TcII; whereas contradictory results were observed for TcIII stocks and no TcIV sequence has been analyzed yet. Herein, we have gone deeper into this matter analyzing 335 distinct SatDNA sequences from 19 T. cruzi stocks representative of DTUs TcI-TcVI for phylogenetic inference. Bayesian phylogenetic tree showed that all sequences were grouped in three major clusters, which corresponded to sequences from DTUs TcI/III, TcII and TcIV; whereas TcV and TcVI stocks had two sets of sequences distributed into TcI/III and TcII clusters. As expected, the lowest genetic distances were found between TcI and TcIII, and between TcV and TcVI sequences; whereas the highest ones were observed between TcII and TcI/III, and among TcIV sequences and those from the remaining DTUs. In addition, signature patterns associated to specific T. cruzi lineages were identified and new primers that improved SatDNA-based qPCR sensitivity were designed. Our findings support the theory that TcIII is not the result of a hybridization event between TcI and TcII, and that TcIV had an independent origin from the other DTUs, contributing to clarifying the evolutionary history of T. cruzi lineages. Moreover, this work opens the possibility of typing samples from Chagas disease patients with low parasitic loads and improving molecular diagnostic methods of T. cruzi infection based on SatDNA sequence amplification.

  15. New insights into Trypanosoma cruzi evolution, genotyping and molecular diagnostics from satellite DNA sequence analysis.

    Science.gov (United States)

    Ramírez, Juan C; Torres, Carolina; Curto, María de Los A; Schijman, Alejandro G

    2017-12-01

    Trypanosoma cruzi has been subdivided into seven Discrete Typing Units (DTUs), TcI-TcVI and Tcbat. Two major evolutionary models have been proposed to explain the origin of hybrid lineages, but while it is widely accepted that TcV and TcVI are the result of genetic exchange between TcII and TcIII strains, the origin of TcIII and TcIV is still a matter of debate. T. cruzi satellite DNA (SatDNA), comprised of 195 bp units organized in tandem repeats, from both TcV and TcVI stocks were found to have SatDNA copies type TcI and TcII; whereas contradictory results were observed for TcIII stocks and no TcIV sequence has been analyzed yet. Herein, we have gone deeper into this matter analyzing 335 distinct SatDNA sequences from 19 T. cruzi stocks representative of DTUs TcI-TcVI for phylogenetic inference. Bayesian phylogenetic tree showed that all sequences were grouped in three major clusters, which corresponded to sequences from DTUs TcI/III, TcII and TcIV; whereas TcV and TcVI stocks had two sets of sequences distributed into TcI/III and TcII clusters. As expected, the lowest genetic distances were found between TcI and TcIII, and between TcV and TcVI sequences; whereas the highest ones were observed between TcII and TcI/III, and among TcIV sequences and those from the remaining DTUs. In addition, signature patterns associated to specific T. cruzi lineages were identified and new primers that improved SatDNA-based qPCR sensitivity were designed. Our findings support the theory that TcIII is not the result of a hybridization event between TcI and TcII, and that TcIV had an independent origin from the other DTUs, contributing to clarifying the evolutionary history of T. cruzi lineages. Moreover, this work opens the possibility of typing samples from Chagas disease patients with low parasitic loads and improving molecular diagnostic methods of T. cruzi infection based on SatDNA sequence amplification.

  16. 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

  17. 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

  18. 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

  19. Development of a Trypanosoma cruzi strain typing assay using MS2 peptide spectral libraries (Tc-STAMS2).

    Science.gov (United States)

    de Oliveira, Gilberto Santos; Kawahara, Rebeca; Rosa-Fernandes, Livia; Mule, Simon Ngao; Avila, Carla Cristi; Teixeira, Marta M G; Larsen, Martin R; Palmisano, Giuseppe

    2018-04-01

    Chagas disease also known as American trypanosomiasis is caused by the protozoan Trypanosoma cruzi. Over the last 30 years, Chagas disease has expanded from a neglected parasitic infection of the rural population to an urbanized chronic disease, becoming a potentially emergent global health problem. T. cruzi strains were assigned to seven genetic groups (TcI-TcVI and TcBat), named discrete typing units (DTUs), which represent a set of isolates that differ in virulence, pathogenicity and immunological features. Indeed, diverse clinical manifestations (from asymptomatic to highly severe disease) have been attempted to be related to T.cruzi genetic variability. Due to that, several DTU typing methods have been introduced. Each method has its own advantages and drawbacks such as high complexity and analysis time and all of them are based on genetic signatures. Recently, a novel method discriminated bacterial strains using a peptide identification-free, genome sequence-independent shotgun proteomics workflow. Here, we aimed to develop a Trypanosoma cruzi Strain Typing Assay using MS/MS peptide spectral libraries, named Tc-STAMS2. The Tc-STAMS2 method uses shotgun proteomics combined with spectral library search to assign and discriminate T. cruzi strains independently on the genome knowledge. The method is based on the construction of a library of MS/MS peptide spectra built using genotyped T. cruzi reference strains. For identification, the MS/MS peptide spectra of unknown T. cruzi cells are identified using the spectral matching algorithm SpectraST. The Tc-STAMS2 method allowed correct identification of all DTUs with high confidence. The method was robust towards different sample preparations, length of chromatographic gradients and fragmentation techniques. Moreover, a pilot inter-laboratory study showed the applicability to different MS platforms. This is the first study that develops a MS-based platform for T. cruzi strain typing. Indeed, the Tc-STAMS2 method

  20. Genotype diversity of Trypanosoma cruzi in small rodents and Triatoma sanguisuga from a rural area in New Orleans, Louisiana.

    Science.gov (United States)

    Herrera, Claudia P; Licon, Meredith H; Nation, Catherine S; Jameson, Samuel B; Wesson, Dawn M

    2015-02-24

    Chagas disease is an anthropozoonosis caused by the protozoan parasite Trypanosoma cruzi that represents a major public health problem in Latin America. Although the United States is defined as non-endemic for Chagas disease due to the rarity of human cases, the presence of T. cruzi has now been amply demonstrated as enzootic in different regions of the south of the country from Georgia to California. In southeastern Louisiana, a high T. cruzi infection rate has been demonstrated in Triatoma sanguisuga, the local vector in this area. However, little is known about the role of small mammals in the wild and peridomestic transmission cycles. This study focused on the molecular identification and genotyping of T. cruzi in both small rodents and T. sanguisuga from a rural area of New Orleans, Louisiana. DNA extractions were prepared from rodent heart, liver, spleen and skeletal muscle tissues and from cultures established from vector feces. T. cruzi infection was determined by standard PCR using primers specific for the minicircle variable region of the kinetoplastid DNA (kDNA) and the highly repetitive genomic satellite DNA (satDNA). Genotyping of discrete typing units (DTUs) was performed by amplification of mini-exon and 18S and 24Sα rRNA genes and subsequent sequence analysis. The DTUs TcI, TcIV and, for the first time, TcII, were identified in tissues of mice and rats naturally infected with T. cruzi captured in an area of New Orleans, close to the house where the first human case of Chagas disease was reported in Louisiana. The T. cruzi infection rate in 59 captured rodents was 76%. The frequencies of the detected DTUs in such mammals were TcI 82%, TcII 22% and TcIV 9%; 13% of all infections contained more than one DTU. Our results indicate a probable presence of a considerably greater diversity in T. cruzi DTUs circulating in the southeastern United States than previously reported. Understanding T. cruzi transmission dynamics in sylvatic and peridomestic cycles

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

    International Nuclear Information System (INIS)

    Macedo, Edangelo M.S. de; Silva, Maria G.V.; Wiggers, Helton J.; Montanari, Carlos A.; Braz-Filho, Raimundo; Andricopulo, Adriano D.

    2009-01-01

    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 i ) is in the low micromolar concentration and it was determined by isothermal titration calorimetry to be 27.3 +-2.47 μmol L -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. A Highly Sensitive Rapid Diagnostic Test for Chagas Disease That Utilizes a Recombinant Trypanosoma cruzi Antigen

    Science.gov (United States)

    Barfield, C. A.; Barney, R. S.; Crudder, C. H.; Wilmoth, J. L.; Stevens, D. S.; Mora-Garcia, S.; Yanovsky, M. J.; Weigl, B. H.; Yanovsky, J.

    2011-01-01

    Improved diagnostic tests for Chagas disease are urgently needed. A new lateral flow rapid test for Chagas disease is under development at PATH, in collaboration with Laboratorio Lemos of Argentina, which utilizes a recombinant antigen for detection of antibodies to Trypanosoma cruzi. To evaluate the performance of this test, 375 earlier characterized serum specimens from a region where Chagas is endemic were tested using a reference test (the Ortho T. cruzi ELISA, Johnson & Johnson), a commercially available rapid test (Chagas STAT-PAK, Chembio), and the PATH–Lemos rapid test. Compared to the composite reference tests, the PATH–Lemos rapid test demonstrated an optimal sensitivity of 99.5% and specificity of 96.8%, while the Chagas STAT-PAK demonstrated a sensitivity of 95.3% and specificity of 99.5%. These results indicate that the PATH–Lemos rapid test shows promise as an improved and reliable tool for screening and diagnosis of Chagas disease. PMID:21342808

  3. Prevalencia de infeccion a Trypanosoma cruzi en donadores de sangre en el Estado de Jalisco, Mexico

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    Francisco Trujillo Contreras

    1993-06-01

    Full Text Available Durante el periodo de Octubre de 1991 a Marzo de 1992, se tomaron 3419 muestras de donadores de sangre de 12 localidades rurales y de 8 hospitales urbanos a los que se les realizo un estúdio serológico mediante la reacción de hemaglutinación indirecta encontrándose anticuerpos contra Trypanosoma cruzi en 44 indivíduos 39 masculinosy 5 femininos. El 90,9% de donantes fueron masculinos. De acuerdo a su procedencia, el 73,5% fué del área urbana y el 26,5% del área rural. De acuerdo a los resultados el riesgo de transmisión de T. cruzi por transfusión sanguinea está latente por la creciente urbanización de la enfermedad de Chagas.

  4. Genómica del Trypanosoma cruzi. Nuevas oportunidades para tratar el mal de Chagas

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    Jorge A. Huete-Pérez

    2006-12-01

    Full Text Available LA SECUENCIACIÓN DEL GENOMA HUMANO PUBLICADA EN FEBRERO de 2001 ha sido considerada como el hito científico más importante del siglo XX. La secuenciación, cuatro años más tarde, de tres parásitos tripanosmatidas, entre ellos el Trypanosoma cruzi, podría ser también catalogada como uno de los acontecimientos científicos más importantes para la salud publica del continente americano. Aquí se presenta un panorama general sobre los resultados más significativos del estudio geonómico del T. cruzi, se abordan los trabajos realizados por nuestro laboratorio en la Universidad Centroamericana, finalizando con una discusión sobre las perspectivas del uso de la genómica en Nicaragua.

  5. Nutritional Status Driving Infection by Trypanosoma cruzi: Lessons from Experimental Animals

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    Guilherme Malafaia

    2011-01-01

    Full Text Available This paper reviews the scientific knowledge about protein-energy and micronutrient malnutrition in the context of Chagas disease, especially in experimental models. The search of articles was conducted using the electronic databases of SciELO (Scientific Electronic Library Online, PubMed and MEDLINE published between 1960 and March 2010. It was possible to verify that nutritional deficiencies (protein-energy malnutrition and micronutrient malnutrition exert a direct effect on the infection by T. cruzi. However, little is known about the immunological mechanisms involved in the relationship “nutritional deficiencies and infection by T. cruzi”. A hundred years after the discovery of Chagas disease many aspects of this illness still require clarification, including the effects of nutritional deficiencies on immune and pathological mechanisms of T. cruzi infection.

  6. The role of adaptations in two-strain competition for sylvatic Trypanosoma cruzi transmission.

    Science.gov (United States)

    Kribs-Zaleta, Christopher M; Mubayi, Anuj

    2012-01-01

    This study presents a continuous-time model for the sylvatic transmission dynamics of two strains of Trypanosoma cruzi enzootic in North America, in order to study the role that adaptations of each strain to distinct modes of transmission (classical stercorarian transmission on the one hand, and vertical and oral transmission on the other) may play in the competition between the two strains. A deterministic model incorporating contact process saturation predicts competitive exclusion, and reproductive numbers for the infection provide a framework for evaluating the competition in terms of adaptive trade-off between distinct transmission modes. Results highlight the importance of oral transmission in mediating the competition between horizontal (stercorarian) and vertical transmission; its presence as a competing contact process advantages vertical transmission even without adaptation to oral transmission, but such adaptation appears necessary to explain the persistence of (vertically-adapted) T. cruzi IV in raccoons and woodrats in the southeastern United States.

  7. Seroprevalence of Trypanosoma cruzi in rural Ecuador and clustering of seropositivity within households.

    Science.gov (United States)

    Black, Carla L; Ocaña-Mayorga, Sofía; Riner, Diana K; Costales, Jaime A; Lascano, Mauricio S; Arcos-Terán, Laura; Preisser, John S; Seed, J Richard; Grijalva, Mario J

    2009-12-01

    We performed a cross-sectional study of Trypanosoma cruzi seroprevalence in 14 communities in three provinces of Ecuador and estimated the magnitude of the association of seropositive individuals within households. A total of 3,286 subjects from 997 households were included. Seroprevalence was 5.7%, 1.0%, and 3.6% in subjects in the Manabí, Guayas, and Loja provinces, respectively. Seroprevalence increased with increasing age in Manabí and Guayas, whereas in Loja, the highest prevalence occurred in children Loja, the odds of seropositivity were more than two times greater for an individual living in a household with another seropositive person. Our results indicate that transmission of T. cruzi is ongoing in Ecuador, although intensity of transmission and mechanisms of interaction between humans and the insect vectors of disease vary between geographic regions.

  8. Genome and transcriptome studies of the protozoan parasites Trypanosoma cruzi and Giardia intestinalis

    OpenAIRE

    Franzén, Oscar

    2012-01-01

    Trypanosoma cruzi and Giardia intestinalis are two human pathogens and protozoan parasites responsible for the diseases Chagas disease and giardiasis, respectively. Both diseases cause su ering and illness in several million individuals. The former disease occurs primarily in South America and Central America, and the latter disease occurs worldwide. Current therapeutics are toxic and lack e cacy, and potential vaccines are far from the market. Increased knowledge about the bio...

  9. Performance Assessment of a Trypanosoma cruzi Chimeric Antigen in Multiplex Liquid Microarray Assays.

    Science.gov (United States)

    Santos, Fred Luciano Neves; Celedon, Paola Alejandra Fiorani; Zanchin, Nilson Ivo Tonin; Leitolis, Amanda; Crestani, Sandra; Foti, Leonardo; de Souza, Wayner Vieira; Gomes, Yara de Miranda; Krieger, Marco Aurélio

    2017-10-01

    Diagnosing chronic Chagas disease (CD) requires antibody-antigen detection methods, which are traditionally based on enzymatic assay techniques whose performance depend on the type and quality of antigen used. Previously, 4 recombinant chimeric proteins from the Instituto de Biologia Molecular do Paraná (IBMP-8.1 to 8.4) comprising immuno-dominant regions of diverse Trypanosoma cruzi antigens showed excellent diagnostic performance in enzyme-linked immunosorbent assays. Considering that next-generation platforms offer improved CD diagnostic accuracy with different T. cruzi -specific recombinant antigens, we assessed the performance of these chimeras in liquid microarrays (LMAs). The chimeric proteins were expressed in Escherichia coli and purified by chromatography. Sera from 653 chagasic and 680 healthy individuals were used to assess the performance of these chimeras in detecting specific anti- T. cruzi antibodies. Accuracies ranged from 98.1 to 99.3%, and diagnostic odds ratio values were 3,548 for IBMP-8.3, 4,826 for IBMP-8.1, 7,882 for IBMP-8.2, and 25,000 for IBMP-8.4. A separate sera bank (851 samples) was employed to assess cross-reactivity with other tropical diseases. Leishmania , a pathogen with high similarity to T. cruzi , showed cross-reactivity rates ranging from 0 to 2.17%. Inconclusive results were negligible (0 to 0.71%). Bland-Altman and Deming regression analysis based on 200 randomly selected CD-positive and negative samples demonstrated interchangeability with respect to CD diagnostic performance in both singleplex and multiplex assays. Our results suggested that these chimeras can potentially replace antigens currently used in commercially available assay kits. Moreover, the use of multiplex platforms, such as LMA assays employing 2 or more IBMP antigens, would abrogate the need for 2 different testing techniques when diagnosing CD. Copyright © 2017 American Society for Microbiology.

  10. Effect of ionizing radiation exposure on Trypanosoma cruzi ubiquitin-proteasome system.

    Science.gov (United States)

    Cerqueira, Paula G; Passos-Silva, Danielle G; Vieira-da-Rocha, João P; Mendes, Isabela Cecilia; de Oliveira, Karla A; Oliveira, Camila F B; Vilela, Liza F F; Nagem, Ronaldo A P; Cardoso, Joseane; Nardelli, Sheila C; Krieger, Marco A; Franco, Glória R; Macedo, Andrea M; Pena, Sérgio D J; Schenkman, Sérgio; Gomes, Dawidson A; Guerra-Sá, Renata; Machado, Carlos R

    2017-03-01

    In recent years, proteasome involvement in the damage response induced by ionizing radiation (IR) became evident. However, whether proteasome plays a direct or indirect role in IR-induced damage response still unclear. Trypanosoma cruzi is a human parasite capable of remarkable high tolerance to IR, suggesting a highly efficient damage response system. Here, we investigate the role of T. cruzi proteasome in the damage response induced by IR. We exposed epimastigotes to high doses of gamma ray and we analyzed the expression and subcellular localization of several components of the ubiquitin-proteasome system. We show that proteasome inhibition increases IR-induced cell growth arrest and proteasome-mediated proteolysis is altered after parasite exposure. We observed nuclear accumulation of 19S and 20S proteasome subunits in response to IR treatments. Intriguingly, the dynamic of 19S particle nuclear accumulation was more similar to the dynamic observed for Rad51 nuclear translocation than the observed for 20S. In the other hand, 20S increase and nuclear translocation could be related with an increase of its regulator PA26 and high levels of proteasome-mediated proteolysis in vitro. The intersection between the opposed peaks of 19S and 20S protein levels was marked by nuclear accumulation of both 20S and 19S together with Ubiquitin, suggesting a role of ubiquitin-proteasome system in the nuclear protein turnover at the time. Our results revealed the importance of proteasome-mediated proteolysis in T. cruzi IR-induced damage response suggesting that proteasome is also involved in T. cruzi IR tolerance. Moreover, our data support the possible direct/signaling role of 19S in DNA damage repair. Based on these results, we speculate that spatial and temporal differences between the 19S particle and 20S proteasome controls proteasome multiple roles in IR damage response. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Valeria P Sülsen

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

  12. Trypanosoma cruzi response to sterol biosynthesis inhibitors: morphophysiological alterations leading to cell death.

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    Rafael Luis Kessler

    Full Text Available The protozoan parasite Trypanosoma cruzi displays similarities to fungi in terms of its sterol lipid biosynthesis, as ergosterol and other 24-alkylated sterols are its principal endogenous sterols. The sterol pathway is thus a potential drug target for the treatment of Chagas disease. We describe here a comparative study of the growth inhibition, ultrastructural and physiological changes leading to the death of T. cruzi cells following treatment with the sterol biosynthesis inhibitors (SBIs ketoconazole and lovastatin. We first calculated the drug concentration inhibiting epimastigote growth by 50% (EC(50/72 h or killing all cells within 24 hours (EC(100/24 h. Incubation with inhibitors at the EC(50/72 h resulted in interesting morphological changes: intense proliferation of the inner mitochondrial membrane, which was corroborated by flow cytometry and confocal microscopy of the parasites stained with rhodamine 123, and strong swelling of the reservosomes, which was confirmed by acridine orange staining. These changes to the mitochondria and reservosomes may reflect the involvement of these organelles in ergosterol biosynthesis or the progressive autophagic process culminating in cell lysis after 6 to 7 days of treatment with SBIs at the EC(50/72 h. By contrast, treatment with SBIs at the EC(100/24 h resulted in rapid cell death with a necrotic phenotype: time-dependent cytosolic calcium overload, mitochondrial depolarization and reservosome membrane permeabilization (RMP, culminating in cell lysis after a few hours of drug exposure. We provide the first demonstration that RMP constitutes the "point of no return" in the cell death cascade, and propose a model for the necrotic cell death of T. cruzi. Thus, SBIs trigger cell death by different mechanisms, depending on the dose used, in T. cruzi. These findings shed new light on ergosterol biosynthesis and the mechanisms of programmed cell death in this ancient protozoan parasite.

  13. 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.

  14. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae: Aspects of the ecology of parasite-vector interactions.

    Directory of Open Access Journals (Sweden)

    Everton Falcão de Oliveira

    2017-02-01

    Full Text Available Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial

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

    Directory of Open Access Journals (Sweden)

    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.

  16. Experimental infection and transmission of Leishmania by Lutzomyia cruzi (Diptera: Psychodidae): Aspects of the ecology of parasite-vector interactions.

    Science.gov (United States)

    Falcão de Oliveira, Everton; Oshiro, Elisa Teruya; Fernandes, Wagner de Souza; Murat, Paula Guerra; Medeiros, Márcio José de; Souza, Alda Izabel; Oliveira, Alessandra Gutierrez de; Galati, Eunice Aparecida Bianchi

    2017-02-01

    Several parameters should be addressed before incriminating a vector for Leishmania transmission. Those may include its ability to become infected by the same Leishmania species found in humans, the degree of attractiveness for reservoirs and humans and capacity to sustain parasite infection under laboratory conditions. This study evaluated the vectorial capacity of Lutzomyia cruzi for Leishmania infantum and gathered information on its ability to harbor L. amazonensis. Laboratory-reared Lu. cruzi were infected experimentally by feeding them on dogs infected naturally with L. infantum and hamsters infected with L. amazonensis. Sand fly attractiveness to dogs and humans was determined using wild caught insects. The expected daily survival of infected Lu. cruzi, the duration of the gonotrophic cycle, and the extrinsic incubation period were also investigated for both parasites. Vector competence was investigated for both Leishmania species. The mean proportion of female sand flies that fed on hosts was 0.40. For L. infantum and L. amazonensis, Lu. cruzi had experimental infection rates of 10.55% and 41.56%, respectively. The extrinsic incubation period was 3 days for both Leishmania species, regardless of the host. Survival expectancy of females infected with L. infantum and L. amazonensis after completing the gonotrophic cycle was 1.32 and 0.43, respectively. There was no association between L. infantum infection and sand fly longevity, but L. amazonensis-infected flies had significantly greater survival probabilities. Furthermore, egg-laying was significantly detrimental to survival. Lu. cruzi was found to be highly attracted to both dogs and humans. After a bloodmeal on experimentally infected hosts, both parasites were able to survive and develop late-stage infections in Lu. cruzi. However, transmission was demonstrated only for L. amazonensis-infected sand flies. In conclusion, Lu. cruzi fulfilled several of the requirements of vectorial capacity for L. infantum

  17. Protein preparation, crystallization and preliminary X-ray analysis of Trypanosoma cruzi nucleoside diphosphate kinase 1

    International Nuclear Information System (INIS)

    Gómez Barroso, J. A.; Pereira, H.; Miranda, M.; Pereira, C.; Garratt, R. C.; Aguilar, C. F.

    2010-01-01

    T. cruzi TcNDPK1 was overexpressed in Escherichia coli as an N-terminally poly-His-tagged fusion protein and crystallized. The flagellated protozoan parasite Trypanosoma cruzi is the aetiological agent of Chagas disease. Nucleoside diphosphate kinases (NDPKs) are enzymes that are involved in energy management and nucleoside balance in the cell. T. cruzi TcNDPK1, a canonical isoform, was overexpressed in Escherichia coli as an N-terminally poly-His-tagged fusion protein and crystallized. Crystals grew after 72 h in 0.2 M MgCl 2 , 20% PEG 3350. Data were collected to 3.5 Å resolution using synchrotron X-ray radiation at the National Synchrotron Light Laboratory (Campinas, Brazil). The crystals belonged to the trigonal space group P3, with unit-cell parameters a = b = 127.84, c = 275.49 Å. Structure determination is under way and will provide relevant information that may lead to the first step in rational drug design for the treatment of Chagas disease

  18. Natural Trypanosoma cruzi infection in dogs of endemic areas of the Argentine Republic

    Directory of Open Access Journals (Sweden)

    Marta A. Lauricella

    1989-04-01

    Full Text Available The population dynamics and the prevalence of chagasic infection of 352 dogs living in 108 rural houses infested by triatomines were studied. The region was divided into three sections according to increasing distances to an urban area. Each animal was identified by means of its particular characteristics and built, and its owners gave information about its habits. By means of xenodiagnosis, serology and ECG studies, prevalences of infection, parasitological-serological correlation, percentage of altered electrocardiographic outlines and percentage of houses with parasitemic dogs, were determined. The rural area showed a characteristic T. cruzi infection pattern and differences in the canine population parameters with respect to the other areas were observed: a higher proportion of puppies than adult dogs, a more sedentary population, higher prevalences of infection, as measured by xenodiagnosis, in dogs, and the highest proportion of bedroom insects infected with T. cruzi. It is assumed that the sedentary characteristics of the human population in that rural area impinge in the blood offer to the triatomine population, and the high percentage of parasitemic dogs of the area, contribute to the rise of "kissing ougs" infected with T. cruzi found in bedrooms.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2016-01-01

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

  2. Potential Role of Carvedilol in the Cardiac Immune Response Induced by Experimental Infection with Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Aline Luciano Horta

    2017-01-01

    Full Text Available Trypanosoma cruzi causes a cardiac infection characterized by an inflammatory imbalance that could become the inciting factor of the illness. To this end, we evaluated the role of carvedilol, a beta-blocker with potential immunomodulatory properties, on the immune response in C57BL/6 mice infected with VL-10 strain of T. cruzi in the acute phase. Animals (n=40 were grouped: (i not infected, (ii infected, (iii infected + carvedilol, and (iv not infected + carvedilol. We analyzed parameters related to parasitemia, plasma levels of TNF, IL-10, and CCL2, and cardiac histopathology after the administration of carvedilol for 30 days. We did not observe differences in the maximum peaks of parasitemia in the day of their detection among the groups. The plasma TNF was elevated at 60 days of infection in mice treated or not with carvedilol. However, we observed a decreased CCL2 level and increased IL-10 levels in those infected animals treated with carvedilol, which impacted the reduction of the inflammatory infiltration in cardiac tissue. For this experimental model, carvedilol therapy was not able to alter the levels of circulating parasites but modulates the pattern of CCL2 and IL-10 mediators when the VL10 strain of T. cruzi was used in C57BL6 mice.

  3. Occurrence and Probability Maps of Lutzomyia longipalpis and Lutzomyia cruzi (Diptera: Psychodidae: Phlebotominae) in Brazil.

    Science.gov (United States)

    Andrade-Filho, J D; Scholte, R G C; Amaral, A L G; Shimabukuro, P H F; Carvalho, O S; Caldeira, R L

    2017-09-01

    Leishmaniases are serious diseases caused by trypanosomatid protozoans of the genus Leishmania transmitted by the bite of phlebotomine sand flies. We analyzed records pertaining to Lutzomyia longipalpis (Lutz and Neiva, 1912) and Lutzomyia cruzi (Mangabeira, 1938) in Brazil from the following sources: the collection of phlebotomine sand flies of the Centro de Pesquisas René Rachou/Fiocruz (FIOCRUZ-COLFLEB), the "SpeciesLink" (CRIA) database, from systematic surveys of scientific articles and gray literature (dissertations, theses, and communications), and disease data obtained from the Information System for Notifiable Diseases/Ministry of Health (SINAN/MS). Environmental data and ecological niche modeling (ESMS) using the approach of MaxEnt algorithm produced maps of occurrence probability for both Lu. longipalpis and Lu. cruzi. Lutzomyia longipalpis was found in 229 Brazilian municipalities and Lu. cruzi in 27. The species were sympatric in 16 municipalities of the Central-West region of Brazil. Our results show that Lu. longipalpis is widely distributed and associated with the high number of cases of visceral leishmaniasis reported in Brazil. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  4. Trypanosoma cruzi benznidazole susceptibility in vitro does not predict the therapeutic outcome of human Chagas disease

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    Margoth Moreno

    2010-11-01

    Full Text Available Therapeutic failure of benznidazole (BZ is widely documented in Chagas disease and has been primarily associated with variations in the drug susceptibility of Trypanosoma cruzi strains. In humans, therapeutic success has been assessed by the negativation of anti-T. cruzi antibodies, a process that may take up to 10 years. A protocol for early screening of the drug resistance of infective strains would be valuable for orienting physicians towards alternative therapies, with a combination of existing drugs or new anti-T. cruzi agents. We developed a procedure that couples the isolation of parasites by haemoculture with quantification of BZ susceptibility in the resultant epimastigote forms. BZ activity was standardized with reference strains, which showed IC50 to BZ between 7.6-32 µM. The assay was then applied to isolates from seven chronic patients prior to administration of BZ therapy. The IC50 of the strains varied from 15.6 ± 3-51.4 ± 1 µM. Comparison of BZ susceptibility of the pre-treatment isolates of patients considered cured by several criteria and of non-cured patients indicates that the assay does not predict therapeutic outcome. A two-fold increase in BZ resistance in the post-treatment isolates of two patients was verified. Based on the profile of nine microsatellite loci, sub-population selection in non-cured patients was ruled out.

  5. Aldo-keto reductase and alcohol dehydrogenase contribute to benznidazole natural resistance in Trypanosoma cruzi.

    Science.gov (United States)

    González, Laura; García-Huertas, Paola; Triana-Chávez, Omar; García, Gabriela Andrea; Murta, Silvane Maria Fonseca; Mejía-Jaramillo, Ana M

    2017-12-01

    The improvement of Chagas disease treatment is focused not only on the development of new drugs but also in understanding mechanisms of action and resistance to drugs conventionally used. Thus, some strategies aim to detect specific changes in proteins between sensitive and resistant parasites and to evaluate the role played in these processes by functional genomics. In this work, we used a natural Trypanosoma cruzi population resistant to benznidazole, which has clones with different susceptibilities to this drug without alterations in the NTR I gene. Using 2DE-gel electrophoresis, the aldo-keto reductase and the alcohol dehydrogenase proteins were found up regulated in the natural resistant clone and therefore their possible role in the resistance to benznidazole and glyoxal was investigated. Both genes were overexpressed in a drug sensitive T. cruzi clone and the biological changes in response to these compounds were evaluated. The results showed that the overexpression of these proteins enhances resistance to benznidazole and glyoxal in T. cruzi. Moreover, a decrease in mitochondrial and cell membrane damage was observed, accompanied by a drop in the intracellular concentration of reactive oxygen species after treatment. Our results suggest that these proteins are involved in the mechanism of action of benznidazole. © 2017 John Wiley & Sons Ltd.

  6. The active transport of histidine and its role in ATP production in Trypanosoma cruzi.

    Science.gov (United States)

    Barisón, M J; Damasceno, F S; Mantilla, B S; Silber, A M

    2016-08-01

    Trypanosoma cruzi, the aetiological agent of Chagas's disease, metabolizes glucose, and after its exhaustion, degrades amino acids as energy source. Here, we investigate histidine uptake and its participation in energy metabolism. No putative genes for the histidine biosynthetic pathway have been identified in genome databases of T. cruzi, suggesting that its uptake from extracellular medium is a requirement for the viability of the parasite. From this assumption, we characterized the uptake of histidine in T. cruzi, showing that this amino acid is incorporated through a single and saturable active system. We also show that histidine can be completely oxidised to CO2. This finding, together with the fact that genes encoding the putative enzymes for the histidine - glutamate degradation pathway were annotated, led us to infer its participation in the energy metabolism of the parasite. Here, we show that His is capable of restoring cell viability after long-term starvation. We confirm that as an energy source, His provides electrons to the electron transport chain, maintaining mitochondrial inner membrane potential and O2 consumption in a very efficient manner. Additionally, ATP biosynthesis from oxidative phosphorylation was found when His was the only oxidisable metabolite present, showing that this amino acid is involved in bioenergetics and parasite persistence within its invertebrate host.

  7. Immunoglobulin M antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi in chronic chagasic patients.

    Science.gov (United States)

    Vasconcelos, Romero H T; Azevedo, Elisa A N; Cavalcanti, Maria G A M; Silva, Edimilson D; Ferreira, Antonio G P; Morais, Clarice N L; Gomes, Yara M

    2011-05-01

    Previous works of our research group have demonstrated aspects of the humoral immune response of chronic Chagas disease using the cytoplasmatic repetitive antigen (CRA) and the flagellar repetitive antigen (FRA) of Trypanosoma cruzi. The aim of this work was to analyze the presence of specific immunoglobulin M (IgM) antibodies in chronic chagasic patients using these recombinant antigens of T. cruzi. The positivity of IgM in chronic chagasic patients against CRA and FRA antigens was determined by indirect enzyme-linked immunosorbent assay. We reported no statistical significant differences between the levels of IgM for both recombinant antigens and the different chronic clinical forms of Chagas disease. However, a small proportion of chronic chagasic patients analyzed in this study was positive for this antibody isotype. The findings of this study indicate that the IgM antibodies cannot be used to elucidate the differences in the profile of humoral immune response among chronic chagasic patients with different clinical forms using the CRA and FRA recombinant antigens of T. cruzi. Copyright © 2011 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

  8. Large-scale conformational changes of Trypanosoma cruzi proline racemase predicted by accelerated molecular dynamics simulation.

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    César Augusto F de Oliveira

    2011-10-01

    Full Text Available Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi, is a life-threatening illness affecting 11-18 million people. Currently available treatments are limited, with unacceptable efficacy and safety profiles. Recent studies have revealed an essential T. cruzi proline racemase enzyme (TcPR as an attractive candidate for improved chemotherapeutic intervention. Conformational changes associated with substrate binding to TcPR are believed to expose critical residues that elicit a host mitogenic B-cell response, a process contributing to parasite persistence and immune system evasion. Characterization of the conformational states of TcPR requires access to long-time-scale motions that are currently inaccessible by standard molecular dynamics simulations. Here we describe advanced accelerated molecular dynamics that extend the effective simulation time and capture large-scale motions of functional relevance. Conservation and fragment mapping analyses identified potential conformational epitopes located in the vicinity of newly identified transient binding pockets. The newly identified open TcPR conformations revealed by this study along with knowledge of the closed to open interconversion mechanism advances our understanding of TcPR function. The results and the strategy adopted in this work constitute an important step toward the rationalization of the molecular basis behind the mitogenic B-cell response of TcPR and provide new insights for future structure-based drug discovery.

  9. Crystallization and preliminary X-ray analysis of aspartate transcarbamoylase from the parasitic protist Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Matoba, Kazuaki; Nara, Takeshi; Aoki, Takashi; Honma, Teruki; Tanaka, Akiko; Inoue, Masayuki; Matsuoka, Shigeru; Inaoka, Daniel Ken; Kita, Kiyoshi; Harada, Shigeharu

    2009-01-01

    Aspartate transcarbamoylase, the second enzyme of the de novo pyrimidine-biosynthetic pathway, from T. cruzi has been purified and crystallized for X-ray structure analysis. Aspartate transcarbamoylase (ATCase), the second enzyme of the de novo pyrimidine-biosynthetic pathway, catalyzes the production of carbamoyl aspartate from carbamoyl phosphate and l-aspartate. In contrast to Escherichia coli ATCase and eukaryotic CAD multifunctional fusion enzymes, Trypanosoma cruzi ATCase lacks regulatory subunits and is not part of the multifunctional fusion enzyme. Recombinant T. cruzi ATCase expressed in E. coli was purified and crystallized in a ligand-free form and in a complex with carbamoyl phosphate at 277 K by the sitting-drop vapour-diffusion technique using polyethylene glycol 3350 as a precipitant. Ligand-free crystals (space group P1, unit-cell parameters a = 78.42, b = 79.28, c = 92.02 Å, α = 69.56, β = 82.90, γ = 63.25°) diffracted X-rays to 2.8 Å resolution, while those cocrystallized with carbamoyl phosphate (space group P2 1 , unit-cell parameters a = 88.41, b = 158.38, c = 89.00 Å, β = 119.66°) diffracted to 1.6 Å resolution. The presence of two homotrimers in the asymmetric unit (38 kDa × 6) gives V M values of 2.3 and 2.5 Å 3 Da −1 for the P1 and P2 1 crystal forms, respectively

  10. Maternal-fetal transmission of Trypanosoma cruzi, a health problem slightly studied in Mexico: case Chiapas

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    Guillermina Campos-Valdez

    2016-05-01

    Full Text Available Objective. To determine the Trypanosoma cruzi infection prevalence in 1125 pregnant women and the transmission frequency to their children from Tapachula and Palenque, Chiapas. Materials and methods. We determined the prevalence by serology tests and the transmission frequency by polymerase chain reaction (PCR and T. cruzi reactivity capacity after 12 months. Results. Total maternal infection prevalence were 23/1 125 (2.04%, 9/600 (1.5% were from Tapachula and 14/525 (2.6% from Palenque. The seropositive women were between 20 and 35 years old, 31.8% have Premature Rapture of Membrane and 9.1% have history of perinatal death. The total percentage of positive newborns by PCR was 9/23 (39.13%, out of those 2/9 (22.2% are from Tapachula and 7/14 (50% from Palenque. The Maternal Fetal transmission frequency was. 2/9 (22.2% in Tapachula and 1/14 (7.14% in Palenque, all positive infants were asynthomatic. Conclusion. The maternal-fetal transmission rate in Chiapas State is variable; the reason could be the maternal immunological status and T. cruzi strain.

  11. A functionalized surface modification with vanadium nanoparticles of various valences against implant-associated bloodstream infection

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    Wang J

    2017-04-01

    Full Text Available Jiaxing Wang,1,* Huaijuan Zhou,2,* Geyong Guo,1 Tao Cheng,1 Xiaochun Peng,1 Xin Mao,1 Jinhua Li,2–4 Xianlong Zhang1 1Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People’s Hospital, Shanghai Jiao Tong University, 2State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 3Department of Orthopaedics and Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, 4University of Chinese Academy of Sciences, Beijing, China *These authors contributed equally to this work Abstract: Bloodstream infection, especially with implants involved, is an often life-threatening condition with high mortality rates, imposing a heavy burden on patients and medical systems. Herein, we firstly deposited homogeneous vanadium metal, V2O3, VO2, and V2O5 nanofilms on quartz glass by magnetron sputtering. Using these platforms, we further investigated the potential antimicrobial efficiency of these nano-VOx films and the interactions of human erythrocytes and bacteria (methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa with our samples in a novel cell–bacteria coculture model. It was demonstrated that these nano-VOx precipitated favorable antibacterial activity on both bacteria, especially on S. aureus, and this effect increased with higher vanadium valence. A possible mechanism accountable for these results might be elevated levels of vanadium-induced intracellular reactive oxygen species. More importantly, based on hemolysis assays, our nano-VOx films were found to be able to kill prokaryotic cells but were not toxic to mammalian cells, holding the potential for the prevention of implant-related hematogenous infections. As far as we know, this is the first report wherein such nano-VOx films have assisted human erythrocytes to combat bacteria in a valence-dependent manner. Additionally, vanadium

  12. Bloodstream Amyloid-beta (1-40) Peptide, Cognition, and Outcomes in Heart Failure.

    Science.gov (United States)

    Bayes-Genis, Antoni; Barallat, Jaume; de Antonio, Marta; Domingo, Mar; Zamora, Elisabet; Vila, Joan; Subirana, Isaac; Gastelurrutia, Paloma; Pastor, M Cruz; Januzzi, James L; Lupón, Josep

    2017-11-01

    In the brain, amyloid-beta generation participates in the pathophysiology of cognitive disorders; in the bloodstream, the role of amyloid-beta is uncertain but may be linked to sterile inflammation and senescence. We explored the relationship between blood levels of amyloid-beta 1-40 peptide (Aβ40), cognition, and mortality (all-cause, cardiovascular, and heart failure [HF]-related) in ambulatory patients with HF. Bloodstream Aβ40 was measured in 939 consecutive patients with HF. Cognition was evaluated with the Pfeiffer questionnaire (adjusted for educational level) at baseline and during follow-up. Multivariate Cox regression analyses and measurements of performance (discrimination, calibration, and reclassification) were used, with competing risk for specific causes of death. Over 5.1 ± 2.9 years, 471 patients died (all-cause): 250 from cardiovascular causes and 131 HF-related. The median Aβ40 concentration was 519.1 pg/mL [Q1-Q3: 361.8-749.9 pg/mL]. The Aβ40 concentration correlated with age, body mass index, renal dysfunction, and New York Heart Association functional class (all P < .001). There were no differences in Aβ40 in patients with and without cognitive impairment at baseline (P = .97) or during follow-up (P = .20). In multivariable analysis, including relevant clinical predictors and N-terminal pro-B-type natriuretic peptide, Aβ40 remained significantly associated with all-cause death (HR, 1.22; 95%CI, 1.10-1.35; P < .001) and cardiovascular death (HR, 1.18; 95%CI, 1.03-1.36; P = .02), but not with HF-related death (HR, 1.13; 95%CI, 0.93-1.37; P = .22). Circulating Aβ40 improved calibration and patient reclassification. Blood levels of Aβ40 are not associated with cognitive decline in HF. Circulating Aβ40 was predictive of mortality and may indicate systemic aging. Copyright © 2017 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  13. Channel-forming activities in the glycosomal fraction from the bloodstream form of Trypanosoma brucei.

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    Melisa Gualdron-López

    Full Text Available BACKGROUND: Glycosomes are a specialized form of peroxisomes (microbodies present in unicellular eukaryotes that belong to the Kinetoplastea order, such as Trypanosoma and Leishmania species, parasitic protists causing severe diseases of livestock and humans in subtropical and tropical countries. The organelles harbour most enzymes of the glycolytic pathway that is responsible for substrate-level ATP production in the cell. Glycolysis is essential for bloodstream-form Trypanosoma brucei and enzymes comprising this pathway have been validated as drug targets. Glycosomes are surrounded by a single membrane. How glycolytic metabolites are transported across the glycosomal membrane is unclear. METHODS/PRINCIPAL FINDINGS: We hypothesized that glycosomal membrane, similarly to membranes of yeast and mammalian peroxisomes, contains channel-forming proteins involved in the selective transfer of metabolites. To verify this prediction, we isolated a glycosomal fraction from bloodstream-form T. brucei and reconstituted solubilized membrane proteins into planar lipid bilayers. The electrophysiological characteristics of the channels were studied using multiple channel recording and single channel analysis. Three main channel-forming activities were detected with current amplitudes 70-80 pA, 20-25 pA, and 8-11 pA, respectively (holding potential +10 mV and 3.0 M KCl as an electrolyte. All channels were in fully open state in a range of voltages ±150 mV and showed no sub-conductance transitions. The channel with current amplitude 20-25 pA is anion-selective (P(K+/P(Cl-∼0.31, while the other two types of channels are slightly selective for cations (P(K+/P(Cl- ratios ∼1.15 and ∼1.27 for the high- and low-conductance channels, respectively. The anion-selective channel showed an intrinsic current rectification that may suggest a functional asymmetry of the channel's pore. CONCLUSIONS/SIGNIFICANCE: These results indicate that the membrane of glycosomes

  14. Identification and Whole Genome Sequencing of the First Case of Kosakonia radicincitans Causing a Human Bloodstream Infection

    OpenAIRE

    Bhatti, Micah D.; Kalia, Awdhesh; Sahasrabhojane, Pranoti; Kim, Jiwoong; Greenberg, David E.; Shelburne, Samuel A.

    2017-01-01

    The taxonomy of Enterobacter species is rapidly changing. Herein we report a bloodstream infection isolate originally identified as Enterobacter cloacae by Vitek2 methodology that we found to be Kosakonia radicincitans using genetic means. Comparative whole genome sequencing of our isolate and other published Kosakonia genomes revealed these organisms lack the AmpC β-lactamase present on the chromosome of Enterobacter sp. A fimbriae operon primarily found in Escherichia coli O157:H7 isolates ...

  15. 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

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    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

  16. Trypanocide Treatment of Women Infected with Trypanosoma cruzi and Its Effect on Preventing Congenital Chagas

    Science.gov (United States)

    Fabbro, Diana L.; Danesi, Emmaria; Olivera, Veronica; Codebó, Maria Olenka; Denner, Susana; Heredia, Cecilia; Streiger, Mirtha; Sosa-Estani, Sergio

    2014-01-01

    With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment before pregnancy. Their children were studied to detect congenital infection. Among 354 “chronically infected mother-biological child” pairs, 132 were treated women and 222 were untreated women. Among the children born to untreated women, we detected 34 infected with T. cruzi (15.3%), whose only antecedent was maternal infection. Among the 132 children of previously treated women, no infection with T. cruzi was found (0.0%) (p<0.05). Among 117 mothers with clinical and serological follow up, 71 had been treated and 46 were untreated. The women were grouped into three groups. Group A: 25 treated before 15 years of age; Group B: 46 treated at 15 or more years of age; Group C: untreated, average age of 29.2±6.2 years at study entry. Follow-up for Groups A, B and C was 16.3±5.8, 17.5±9.2 and 18.6±8.6 years respectively. Negative seroconversion: Group A, 64.0% (16/25); Group B, 32.6% (15/46); Group C, no seronegativity was observed. Clinical electrocardiographic alterations compatible with chagasic cardiomyopathy: Group A 0.0% (0/25); B 2.2% (1/46) and C 15.2% (7/46). The trypanocidal treatment of women with chronic Chagas infection was effective in preventing the congenital transmission of Trypanosoma cruzi to their children; it had also a protective effect on the women's clinical evolution and deparasitation could be demonstrated in many treated women after over 10 years of follow up. PMID:25411847

  17. Trypanocide treatment of women infected with Trypanosoma cruzi and its effect on preventing congenital Chagas.

    Science.gov (United States)

    Fabbro, Diana L; Danesi, Emmaria; Olivera, Veronica; Codebó, Maria Olenka; Denner, Susana; Heredia, Cecilia; Streiger, Mirtha; Sosa-Estani, Sergio

    2014-11-01

    With the control of the vectorial and transfusional routes of infection with Trypanosoma cruzi, congenital transmission has become an important source of new cases. This study evaluated the efficacy of trypanocidal therapy to prevent congenital Chagas disease and compared the clinical and serological evolution between treated and untreated infected mothers. We conducted a multicenter, observational study on a cohort of mothers infected with T. cruzi, with and without trypanocidal treatment before pregnancy. Their children were studied to detect congenital infection. Among 354 "chronically infected mother-biological child" pairs, 132 were treated women and 222 were untreated women. Among the children born to untreated women, we detected 34 infected with T. cruzi (15.3%), whose only antecedent was maternal infection. Among the 132 children of previously treated women, no infection with T. cruzi was found (0.0%) (p<0.05). Among 117 mothers with clinical and serological follow up, 71 had been treated and 46 were untreated. The women were grouped into three groups. Group A: 25 treated before 15 years of age; Group B: 46 treated at 15 or more years of age; Group C: untreated, average age of 29.2 ± 6.2 years at study entry. Follow-up for Groups A, B and C was 16.3 ± 5.8, 17.5 ± 9.2 and 18.6 ± 8.6 years respectively. Negative seroconversion: Group A, 64.0% (16/25); Group B, 32.6% (15/46); Group C, no seronegativity was observed. Clinical electrocardiographic alterations compatible with chagasic cardiomyopathy: Group A 0.0% (0/25); B 2.2% (1/46) and C 15.2% (7/46). The trypanocidal treatment of women with chronic Chagas infection was effective in preventing the congenital transmission of Trypanosoma cruzi to their children; it had also a protective effect on the women's clinical evolution and deparasitation could be demonstrated in many treated women after over 10 years of follow up.

  18. Trypanocidal drugs for chronic asymptomatic Trypanosoma cruzi infection.

    Science.gov (United States)

    Villar, Juan Carlos; Perez, Juan Guillermo; Cortes, Olga Lucia; Riarte, Adelina; Pepper, Micah; Marin-Neto, Jose Antonio; Guyatt, Gordon H

    2014-05-27

    Prevention of chronic chagasic cardiomyopathy (CCC) by treating infected populations with trypanocidal therapy (TT) remains a challenge. Despite a renewed enthusiasm for TT, uncertainty regarding its efficacy, concerns about its safety and limited availability remain barriers for a wider use of conventional drugs. We have updated a previous version of this review. To systematically search, appraise, identify and extract data from eligible studies comparing the outcome of cohorts of seropositive individuals to Trypanosoma cruzi exposed to TT versus placebo or no treatment. We sought eligible studies in electronic databases (Cochrane Central Register of Controlled Trials (CENTRAL), Issue 1, 2014); MEDLINE (Ovid, 1946 to January week 5 2014); EMBASE (Ovid, 1980 to 2014 week 6) and LILACS (up to 6 May 2010)) by combining terms related with the disease and the treatment. The search also included a Google search, handsearch for references in review or selected articles, and search of expert files. We applied no language restrictions. Review authors screened the retrieved references for eligibility (those dealing with human participants treated with TT) and then assessed the pre-selected studies in full for inclusion. We included randomised controlled trials (RCTs) and observational studies that provided data on either mortality or clinical progression of CCC after at least four years of follow-up. Teams of two review authors independently carried out the study selection, data extraction and risk of bias assessment, with a referee resolving disagreement within the pairs. Data collection included study design, characteristics of the population and interventions or exposures and outcome measures. We defined categories of outcome data as parasite-related (positive serology, xenodiagnosis or polymerase chain reaction (PCR) after TT) and participant-related (including efficacy outcomes such as progression towards CCC, all-cause mortality and side effects of TT). We reported

  19. Identification of carbapenemase-mediated resistance among Enterobacteriaceae bloodstream isolates: A molecular study from India

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    Srujana Mohanty

    2017-01-01

    Full Text Available Acquired resistance in carbapenem-resistant Enterobacteriaceae (CRE conferred by carbapenemases is a major concern worldwide. Consecutive, non-duplicate isolates of Escherichia coli (EC and Klebsiella pneumoniae from clinically diagnosed bloodstream infections were screened for the presence of carbapenem resistance by standard disk-diffusion method and minimum inhibitory concentration breakpoints using the Clinical and Laboratory Standards Institute guidelines. Carbapenemase-encoding genes were amplified by polymerase chain reaction. Of 387 isolates (214 K. pneumoniae, 173 EC tested, 93 (24.03% were found to be CRE. Of these, 71 (76.3% were positive for at least one tested carbapenemase gene. The frequency of carbapenemase genes was New Delhi metallo-β-lactamse-1 (65.6%, oxacillinase (OXA-48 (24.7%, OXA-181 (23.6%, Verona integron-encoded metallo-β-lactamase (6.4% and K. pneumoniae carbapenemase (2.1%. Our study identified presence of carbapenemases in a large proportion of CRE isolates. Delineation of resistance mechanisms is important in view of future therapeutics concerned with the treatment of CRE and for aiding control efforts by surveillance and infection control interventions.

  20. Molecular diagnosis of bloodstream infections in onco-haematology patients with PCR/ESI-MS technology.

    Science.gov (United States)

    Jordana-Lluch, Elena; Rivaya, Belén; Marcó, Clara; Giménez, Montserrat; Quesada, Mª Dolores; Escobedo, Agustín; Batlle, Montserrat; Martró, Elisa; Ausina, Vicente

    2017-02-01

    Onco-haematological patients are prone to develop infections, and antibiotic prophylaxis may lead to negative blood cultures. Thus, the microbiological diagnosis and subsequent administration of a targeted antimicrobial therapy is often difficult. The goal of this study was to evaluate the usefulness of IRIDICA (PCR/ESI-MS technology) for the molecular diagnosis of bloodstream infections in this patient group. A total of 463 whole blood specimens from different sepsis episodes in 429 patients were analysed using the PCR/ESI-MS platform, comparing the results with those of blood culture and other clinically relevant information. The sensitivity of PCR/ESI-MS by specimen (excluding polymicrobial infections, n = 25) in comparison with blood culture was 64.3% overall, 69.0% in oncological patients, and 59.3% in haematological patients. When comparing with a clinical infection criterion, overall sensitivity rose to 74.7%, being higher in oncological patients (80.0%) than in haematological patients (67.7%). Thirty-one microorganisms isolated by culture were not detected by IRIDICA, whereas 42 clinically relevant pathogens not isolated by culture were detected moleculary. PCR/ESI-MS offers a reliable identification of pathogens directly from whole blood. While additional studies are needed to confirm our findings, the system showed a lower sensitivity in onco-haematological patients in comparison with previously reported results in patients from the Intensive Care Unit. Copyright © 2016 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  1. Bacillus Cereus catheter related bloodstream infection in a patient in a patient with acute lymphblastic leukemia

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    Lütfiye Öksüz

    2012-01-01

    Full Text Available Bacillus cereus infection is rarely associated with actual infection and for this reason single positive blood culture is usually regarded as contamination . However it may cause a number of infections, such catheter-related blood stream infections. Significant catheter-related bloodstream infections (CRBSI caused by Bacillus spp. are mainly due to B.cereus and have been predominantly reported in immunocompromised hosts1 . Catheter removal is generally advised for management of infection. In this report, catheter-related bacteremia caused by B.cereus in a patient with acute lymphoblastıc leukemia (ALL in Istanbul Medical Faculty was presented.A 44-year old man presented with fatigue, weight loss, epistaxis and high fever. A double-lumen Hickman–catheter (Bard 12.0 Fr, Round Dual Lumen was inserted by surgical cut-down to access the right subclavian vein which would be necessary for allogeneic stem cell transplantation. Three weeks later the patient presented with high fever and headache. Bacillus spp. was isolated from the cathether while blood culture obtained from the peripheral vein remained negative. The bacterial identification was confirmed as B.cereus using VITEK identification system It has been reported Bacillus cereus septicemia may be fatal in immunocompromised hosts despite broad-spectrum appropriate treatment10. Catheter removal is essential for prevention of recurrent bacteremia. Long-term cathater salvage should be reserved for appropriate patient group.

  2. Impact of universal disinfectant cap implementation on central line-associated bloodstream infections.

    Science.gov (United States)

    Merrill, Katreena Collette; Sumner, Sharon; Linford, Lorraine; Taylor, Carrie; Macintosh, Christopher

    2014-12-01

    Central line-associated bloodstream infections (CLABSIs) result in increased length of stay, cost, and patient morbidity and mortality. One CLABSI prevention method is disinfection of intravenous access points. The literature suggests that placing disinfectant caps over needleless connectors decreases CLABSI risk. A quasi-experimental intervention study was conducted in a >430-bed trauma I center. In addition to an existing standard central line bundle, a new intervention consisting of a luer-lock disinfectant cap with 70% alcohol was implemented in all intravenous (IV) needleless connectors on patients with peripheral and central lines. Compliance to the disinfectant cap was monitored weekly. A generalized linear model using a Poisson distribution was fit to determine if there were significant relationships between CLABSIs and disinfectant cap use. Impacts on costs were also examined. The rate of CLABSI decreased following implementation of the disinfectant cap. The incidence rate ratios (.577, P = .004) for implementing the disinfectant caps was statistically significant, indicating that the rate of patient infections decreased by >40%. Increased compliance rates were associated with lower infection rates. Disinfectant cap use was associated with an estimated savings of almost $300,000 per year in the hospital studied. Use of a disinfectant cap on IV needleless connectors in addition to an existing standard central line bundle was associated with decreased CLABSI and costs. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  3. Validity of calendar day-based definitions for community-onset bloodstream infections.

    Science.gov (United States)

    Laupland, Kevin B; Gregson, Daniel B; Church, Deirdre L

    2015-04-02

    Community-onset (CO) bloodstream infections (BSI) are those BSI where the blood culture is drawn culture draw or hospital admission are not always available. We evaluated the validity of using 2- or 3- calendar day based definitions for CO-BSI by comparing to a "gold standard" 48-hour definition. Among the population-based cohort of 14,106 episodes of BSI studied, 10,543 were classified as CO based on "gold standard" 48-hour criteria. When 2-day and 3-day definitions were applied, 10,396 and 10,707 CO-BSI episodes were ascertained, respectively. All but 147 (1.4%) true CO-BSI cases were included by using the 2-day definition. When the 3-day definition was applied, all cases of CO-BSI were identified but and additional 164 (1.5%) cases of hospital-onset HO-BSI were also included. Thus the sensitivity and specificity of the 2-day definition was 98.6% and 100% and for the 3-day definition was 100% and 98.5%, respectively. Overall, only 311 (2.2%) cases were potentially miss-classifiable using either the 2- or 3-calendar day based definitions. Use of either a 2- or 3-day definition is highly accurate for classifying CO-BSI.

  4. Infectious tenosynovitis with bloodstream infection caused by Erysipelothrix rhusiopathiae, a case report on an occupational pathogen.

    Science.gov (United States)

    Hofseth, Kristine; Dalen, Håvard; Kibsgaard, Leif; Nebb, Solrun; Kümmel, Angela; Mehl, Arne

    2017-01-05

    Erysipelothrix rhusiopathiae is an established animal pathogen, which may cause infections in humans. It is a gram-positive rod and found in the tonsils or the digestive tracts of animals. The bacterium is occupationally related, as usually only people with frequent animal contacts are infected. We report a case of a patient who was admitted with an infectious tenosynovitis with bloodstream infection due to E. rhusiopathiae, and to our knowledge, this is the first report of a tenosynovitis with systemic manifestation associated with this bacterium. A 52-year old Norwegian man, who worked with transportation of swine cadavers, was admitted to the local hospital with sepsis and unknown focus of infection. A few days earlier he had an injury to the skin of one of his fingers that later proved to be infected with E. rhusiopathiae. There were no other causes for his symptoms than the infectious tenosynovitis with systemic manifestation. The infection resolved on treatment with antibiotics and surgery. A transoesophageal echocardiogram was performed to exclude endocarditis, which may be associated with this pathogen. This case report highlights the importance of clinicians being aware of this bacterium, and we describe risk factors for infection, differences in the clinical manifestations of the disease, challenges with diagnosing the bacterium and adverse effects of immunosuppressive drugs. Recommended treatment is appropriate antibiotic therapy and adequate debridement and surgical drainage of the tendon sheath.

  5. Chronic copper poisoning. III. Effects of copper acetate injected into the bloodstream of sheep

    Energy Technology Data Exchange (ETDEWEB)

    Todd, J R; Thompson, R H

    1964-01-01

    A study was made of the clinical and biochemical effects of injections of copper (as acetate) into the bloodstream of sheep of 100 to 130 lb. liveweight. Copper in a dose of 160 mg. caused death in 3 sheep in a few hours, and 80 mg. caused death in 3 out of 4 sheep, 2 after 2 days and 1 after 11 days. Symptoms, biochemical lesions and post-mortem appearances did not resemble those of chronic copper poisoning, but rather those of gastro-enteritis. Blood glutathione concentrations were not markedly reduced, but haemoconcentration was a prominent feature. Post-mortem examination showed gross congestion of blood vessels and marked inflammatory reactions in the abomasum and small intestine. Single injections of smaller amounts (25 to 40 mg. copper) were tolerated without effect, but repeated injections, twice daily for 2 to 3 days, caused haemolytic episodes in 3 sheep similar to the crisis of chronic copper poisoning in that a marked reduction in blood glutathione concentration and accumulation of methaemoglobin occurred. No other clinical effects were produced, however, and all three animals recovered uneventfully.

  6. Novel sterol metabolic network of Trypanosoma brucei procyclic and bloodstream forms

    Science.gov (United States)

    Nes, Craigen R.; Singha, Ujjal K.; Liu, Jialin; Ganapathy, Kulothungan; Villalta, Fernando; Waterman, Michael R.; Lepesheva, Galina I.; Chaudhuri, Minu; Nes, W. David

    2012-01-01

    Trypanosoma brucei is the protozoan parasite that causes African trypanosomiasis, a neglected disease of people and animals. Co-metabolite analysis, labelling studies using [methyl-2H3]-methionine and substrate/product specificities of the cloned 24-SMT (sterol C24-methyltransferase) and 14-SDM (sterol C14-demethylase) from T. brucei afforded an uncommon sterol metabolic network that proceeds from lanosterol and 31-norlanosterol to ETO [ergosta-5,7,25(27)-trien-3β-ol], 24-DTO [dimethyl ergosta-5,7,25(27)-trienol] and ergosterol [ergosta-5,7,22(23)-trienol]. To assess the possible carbon sources of ergosterol biosynthesis, specifically 13C-labelled specimens of lanosterol, acetate, leucine and glucose were administered to T. brucei and the 13C distributions found were in accord with the operation of the acetate–mevalonate pathway, with leucine as an alternative precursor, to ergostenols in either the insect or bloodstream form. In searching for metabolic signatures of procyclic cells, we observed that the 13C-labelling treatments induce fluctuations between the acetyl-CoA (mitochondrial) and sterol (cytosolic) synthetic pathways detected by the progressive increase in 13C-ergosterol production (control sterol synthesis that is further fluctuated in the cytosol, yielding distinct sterol profiles in relation to cell demands on growth. PMID:22176028

  7. Risk Factors for Bloodstream Infection After Living-donor Liver Transplantation in Children.

    Science.gov (United States)

    Shoji, Kensuke; Funaki, Takanori; Kasahara, Mureo; Sakamoto, Seisuke; Fukuda, Akinari; Vaida, Florin; Ito, Kenta; Miyairi, Isao; Saitoh, Akihiko

    2015-10-01

    Postoperative bloodstream infection (BSI) is the most important determinant of recipient morbidity and mortality after liver transplantation (LT). Children who underwent LT are at the highest risk of developing BSI because of the significant surgical intervention, use of multiple devices, and administration of immunosuppressive agents. However, information regarding the risk factors for BSI in children after LT is limited. We retrospectively reviewed 210 children who underwent living-donor LT at the largest pediatric LT center in Japan. Patients' characteristics, blood culture results and clinical outcomes were extracted from electronic medical records. Univariate and multivariate analyses were performed to identify the risk factors for BSI. Among the 210 LT recipients, 53 (25%) recipients experienced 86 episodes of BSI during the observational period. The source of the BSI was identified only in 38%: catheter-related BSI (27%) peritonitis (7%), urinary tract infection (2%), pneumonia (1%) and infectious endocarditis (1%). A multivariate analysis demonstrated that body weight (P = 0.03), volume of blood loss during LT (P 24 months), blood loss and pediatric end-stage liver disease/model for end-stage liver disease versus positive CMV antigenemia. The volume of blood loss, postoperative CMV antigenemia positivity and body weight were associated with the development of BSI after LT in pediatric living-donor recipients. To identify the age-specific predictors of BSI in children who underwent LT, age-specific analyses are crucial.

  8. [Candida parapsilosis: a major cause of bloodstream infection in a tertiary care hospital in Costa Rica].

    Science.gov (United States)

    Villalobos, Juan M; Castro, José A; Avilés, Alvaro; Peláez, M Claudia; Somogyi, Teresita; Sandoval, Lilliana

    2016-04-01

    Invasive Candida bloodstream infections are frequent and display high mortality in clinical practice. There is scarce published on this topic in Central America. To characterize the epidemiology of candidemia in a hospital setting in Costa Rica. 210 cases of nosocomial candidemia were analyzed in patients over 17 years of age, admitted to Hospital Mexico, between 2007 and 2011. Descriptive and temporary analyses were performed and the risk factors associated with C. parapsilosis and survival were evaluated. The incidence rate of candidemia was 1.47 cases per 1,000 admissions. The non-albicans Candida represented 62% of the isolated yeasts. Except for 2009, C. parapsilosis was the most commonly isolated species in four out of the five years reviewed, followed by C. albicans. There was a strong association between C. parapsilosis, the presence of a central venous catheter (OR: 4.8, CI 95%: 1.8-14.6, p < 0.001) and the use of parenteral nutrition (p: 0.008). The 30-day mortality was 50%. Candida albicans displayed the highest mortality and C. parapsilosis the lowest. Patients who did not receive anti-fungal treatment showed a significantly higher probability of death. The high incidence of candidemia from C. parapsilosis is directly related to the use of central venous catheters and parenteral nutrition. There is a need for creating local guidelines addressing the use of central venous catheters and parenteral nutrition, as well as implementing hand hygiene protocols.

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

    Science.gov (United States)

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

    2016-04-01

    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. 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. 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. 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.

  10. 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.

  11. 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.

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

    Science.gov (United States)

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

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

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    C. Magarinos Torres

    1958-07-01

    Full Text Available Transmission of Chagas disease is realized through contamination of ocular conjunctiva, mucosa or skin with infected dejections eliminated by the insect vectors of Schizotrypanum cruzi (Triatoma infestans, Panstrongylus megistus and Rhodnius prolixus. The triatomid bugs live in holes and craks in the walls, in beds, behind trunks, etc. Found in primitive mud huts covered with thatched roofs, and so the human dwellers have many chances to contract the disease, reinfections being reasonably more to expect than a single inoculation. Experimental work reproducing those natural conditions is welcomed as some important features in the pathologic picture of the disease such as the extensive myocardial fibrosis seen in chronic cases are still incompletely known. Microscopic changes were studied in the heart muscle of seven Cebus monkeys infected by S. cruzi. This animal survives the acute stage of the disease and so is particularly suited to experiments of long duration in which several inoculations of S. cruzi are performed. Three different strains of S. cruzi isolated from acute cases of Chagas' disease were employed. One monkey was injected in the skin with infected blood and necropsied after 252 days. Two monkeys were three times, and one, eight times infected in skin, one of them with contaminated blood, and two with contaminated blood and dejections from infected bugs. The necropsies were performed after 35, 95 and 149 days. One monkey was three times inoculated through the intact ocular conjunctiva (one time with infected blood, two times with dejections from infected bugs, and one time through the wounded buccal mucosa, and necropsied after 134 days. Another monkey was six times inoculated, four times through the intact ocular conjunctiva (one time with contaminated blood, three times with dejections from infected bugs and two times injected in the skin with infected blood, and necropsied after 157 days. Finally, another monkey was nine times

  14. Caracterización biológica y genética de dos clones pertenecientes a los grupos I y II de Trypanosoma cruzi de Colombia

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    Luz Adriana Botero

    2007-01-01

    Resultados. El clon T. cruzi I fue más infectivo, observándose un tropismo preferencial por corazón, recto y músculo esquelético, mientras que el clon T. cruzi II presentó un tropismo preferencial por bazo e hígado. Durante la infección con la mezcla de los clones, se observó que el clon T. cruzi I predominó sobre el T. cruzi II tanto en sangre como en órganos. Conclusiones. Los resultados confirman que las diferencias genéticas entre los grupos de T. cruzi podrían estar determinando el tropismo tisular y de esta manera jugar un papel fundamental en el entendimiento de las manifestaciones clínicas de la enfermedad de Chagas en Colombia.

  15. Immunomodulatory effect of cimetidine on the proliferative responses of splenocytes from T. cruzi-infected rats Efeito imunomodulatório da cimetidina sobre a resposta blastogênica de esplenócitos de ratos infectados por T. cruzi

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    M.N. Sato

    1991-06-01

    Full Text Available The immunomodulatory effect of cimetidine (CIM, a histamine type-2 receptor antagonist, was evaluated in respect to the blastogenic response to Con A of Wistar Furth (WF rats infected by the Y strain of Trypanosoma cruzi (T. cruzi. Enhancement of blastogenesis of normal splenocytes was observed at a concentration of 10-3M. However, the splenocytes from infected animals responded to concentrations of CIM ranging from 10-8 to 10-3M. The mitogenic response to Con A of cells from infected animals was restored in the presence of CIM. The results show that CIM modulates the "in vitro" proliferative response of cells from T. cruzi-infected rats and suggest an immunoregulatory role of histamine and/or of cells that express H2 receptors in this infection.O efeito imunomodulatório da Cimetidine (CIM, um antagonista do receptor de histamina-tipo 2, foi avaliado na resposta blastogênica a Con A em células de ratos Wistar Furth (WF infectados pela cepa Y de Trypanosoma cruzi (T. cruzi. Foi observado que apenas na concentração de 10-3M de Cimetidine houve amplificação da resposta blastogênica de esplenócitos normais a Con A. Entretanto, a capacidade mitogênica de esplenócitos de animais infectados foi restaurada na presença de molaridades da droga que variaram entre 10-8 a 10-3. Os resultados demonstraram que a CIM tem o potencial de modular a resposta mitogênica de células de animais infectados pelo T. cruzi, sugerindo um papel imunoregulatório da histamina e/ou células que expressam receptores H2 nesta infecção.

  16. [Specificity of the intradermal Montenegro test in patients infected by Trypanosoma cruzi from different regions of Peru].

    Science.gov (United States)

    Minaya-Gómez, Gloria; Vargas-Apaza, Silver; Monteza-Zuloeta, Yolanda; Purisaca-Morante, Enrique; Delgado-Diaz, Freddy

    2014-04-01

    In order to assess the specificity of the leishmanin skin test in Chagas disease patients without clinical history of leishmaniasis, present or former. A sample of 102 persons infected with Trypanosoma cruzi (14 acute cases with parasitological diagnosis and 88 chronic cases) through the demonstration of IgG antibodies by ELISA and indirect immunofluorescence (IIF) were evaluated with leishmanin soluble antigen which contained Leishmania (Viannia) peruviana concentration of 25-30 ug/mL. Only five people showed cutaneous hypersensitivity reaction to the application of the antigen between hours 48 and 72. The Leishmanin skin test evaluated was negative in 97 people infected with T. cruzi, thus specificity of 95.1% was achieved. In conclusion, the intradermal Montenegro test is a simple and effective diagnostic tool that also could be used to discriminate infections by Leishmania or T. cruzi, in Peruvian geographic areas where both parasites are present.

  17. 3-H-[1,2]Dithiole as a New Anti-Trypanosoma cruzi Chemotype: Biological and Mechanism of Action Studies

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    Marcos Couto

    2015-08-01

    Full Text Available The current pharmacological Chagas disease treatments, using Nifurtimox or Benznidazole, show limited therapeutic results and are associated with potential side effects, like mutagenicity. Using random screening we have identified new chemotypes that were able to inhibit relevant targets of the Trypanosoma cruzi. We found 3H-[1,2]dithioles with the ability to inhibit Trypanosoma cruzi triosephosphate isomerase (TcTIM. Herein, we studied the structural modifications of this chemotype to analyze the influence of volume, lipophilicity and electronic properties in the anti-T. cruzi activity. Their selectivity to parasites vs. mammalian cells was also examined. To get insights into a possible mechanism of action, the inhibition of the enzymatic activity of TcTIM and cruzipain, using the isolated enzymes, and the inhibition of membrane sterol biosynthesis and excreted metabolites, using the whole parasite, were achieved. We found that this structural framework is interesting for the generation of innovative drugs for the treatment of Chagas disease.

  18. 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

  19. Semisolid liver infusion tryptose supplemented with human urine allows growth and isolation of Trypanosoma cruzi and Trypanosoma rangeli clonal lineages

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    Emanuella Francisco Fajardo

    2016-06-01

    Full Text Available Abstract: INTRODUCTION This work shows that 3% (v/v human urine (HU in semisolid Liver Infusion Tryptose (SSL medium favors the growth of Trypanosoma cruzi and T. rangeli. METHODS Parasites were plated as individual or mixed strains on SSL medium and on SSL medium with 3% human urine (SSL-HU. Isolate DNA was analyzed using polymerase chain reaction (PCR and pulsed-field gel electrophoresis (PFGE. RESULTS SSL-HU medium improved clone isolation. PCR revealed that T. cruzi strains predominate on mixed-strain plates. PFGE confirmed that isolated parasites share the same molecular karyotype as parental cell lines. CONCLUSIONS SSL-HU medium constitutes a novel tool for obtaining T. cruzi and T. rangeli clonal lineages.

  20. 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.

  1. Evaluating the Trends of Bloodstream Infections among Pediatric and Adult Patients at a Teaching Hospital of Kathmandu, Nepal: Role of Drug Resistant Pathogens

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    Narayan Prasad Parajuli

    2017-01-01

    Full Text Available Bloodstream infections (BSIs are among the significant causes of morbidity and mortality for patients of all age groups. However, very little is known about the trends of bacterial bloodstream infections and antimicrobial susceptibilities among pediatric and adult population from Nepal. In this study, we have investigated the different etiological agents responsible for bloodstream infections among pediatric and adult patients and the role of drug resistant organisms in these infections at a tertiary care teaching hospital of Kathmandu, Nepal. A total of 3,088 blood culture specimens obtained from pediatric and adult patients suspected to have bloodstream infections were processed by standard microbiological methods. Significant bacterial pathogens were identified by morphological, biochemical, and serological methods as suggested by American Society for Microbiology. In vitro antimicrobial susceptibility testing was performed by Kirby-Bauer disk diffusion method and interpreted according to the guidelines of Clinical and Laboratory Standards Institute. Overall, incidence of bloodstream infections among the suspected patients was 7.48%. Pediatric patients (n=90, 9.37% were the significant subgroup of patients affected with bloodstream infections compared to adults (p<0.05, CI-95%. Gram positive (n=49, 54.4% bacteria in pediatric and gram negative bacteria (n=141, 78.7% in adult patients were the most common isolates for BSI. Staphylococcus aureus (n=41, 45.6% in pediatric patients and Salmonella enterica (n=40, 28.3% in adult patients were the leading pathogens. Trends of antimicrobial resistance among isolated bacterial strains were significantly high in adults compared to pediatric patients. Methicillin resistant Staphylococcus aureus (MRSA (31.4%, extended spectrum beta-lactamase (ESBL (12.5%, and metallo-beta-lactamase (MBL (3.9% producing gram negatives were major resistant strains. Our study shows higher rates of bloodstream infections in

  2. Trypanosoma cruzi has not lost its S-adenosylmethionine decarboxylase: characterization of the gene and the encoded enzyme.

    Science.gov (United States)

    Persson, K; Aslund, L; Grahn, B; Hanke, J; Heby, O

    1998-01-01

    All attempts to identify ornithine decarboxylase in the human pathogen Trypanosoma cruzi have failed. The parasites have instead been assumed to depend on putrescine uptake and S-adenosylmethionine decarboxylase (AdoMetDC) for their synthesis of the polyamines spermidine and spermine. We have now identified the gene encoding AdoMetDC in T. cruzi by PCR cloning, with degenerate primers corresponding to conserved amino acid sequences in AdoMetDC proteins of other trypanosomatids. The amplified DNA fragment was used as a probe to isolate the complete AdoMetDC gene from a T. cruzi genomic library. The AdoMetDC gene was located on chromosomes with a size of approx. 1.4 Mbp, and contained a coding region of 1110 bp, specifying a sequence of 370 amino acid residues. The protein showed a sequence identity of only 25% with human AdoMetDC, the major differences being additional amino acids present in the terminal regions of the T. cruzi enzyme. As expected, a higher sequence identity (68-72%) was found in comparison with trypanosomatid AdoMetDCs. When the coding region was expressed in Escherichia coli, the recombinant protein underwent autocatalytic cleavage, generating a 33-34 kDa alpha subunit and a 9 kDa beta subunit. The encoded protein catalysed the decarboxylation of AdoMet (Km 0.21 mM) and was stimulated by putrescine but inhibited by the polyamines, weakly by spermidine and strongly by spermine. Methylglyoxal-bis(guanylhydrazone) (MGBG), a potent inhibitor of human AdoMetDC, was a poor inhibitor of the T. cruzi enzyme. This differential sensitivity to MGBG suggests that the two enzymes are sufficiently different to warrant the search for compounds that might interfere with the progression of Chagas' disease by selectively inhibiting T. cruzi AdoMetDC. PMID:9677309

  3. 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)

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

    International Nuclear Information System (INIS)

    Alvim Junior, Joel; Dias, Ricardo L.A.; Correa, Arlene G.; Castilho, Marcelo S.; Oliva, Glaucius

    2005-01-01

    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 μM. (author)

  5. 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...

  6. Staphylococcus species and their Methicillin-Resistance in 7424 Blood Cultures for Suspected Bloodstream Infections

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    Ariana ALMAŞ

    2011-06-01

    Full Text Available Objectives: The aim of this study was to evaluate the distribution of Staphylococcus species in bloodstream infections and to assess their susceptibility to methicillin. Material and Methods: Between January 1st 2008 - December 31st 2010, 7424 blood culture sets were submitted to the Laboratory Department of the Hospital for Clinical Infectious Diseases in Cluj-Napoca, Romania. The blood cultures were performed using BacT/Alert until January 2010 and BacT/Alert 3D automated system (bioMérieux after that date. The blood culture bottles were incubated at 37°C in a continuously monitoring system for up to 7 days. The strain identifications were performed by conventional methods, ApiStaph galleries and Vitek 2 Compact system. Susceptibility to methicillin was determined by disk diffusion method with cefoxitin disk and by using Vitek 2 Compact system. Results: From the total number of performed blood cultures, 568 were positive with Staphylococcus species. From 168 bacteriemic episodes 103 were with Staphylococcus aureus. Among 65 coagulase-negative staphylococci isolates, Staphylococcus epidermidis was the most frequently isolated species (34, followed by Staphylococcus hominis (15, Staphylococcus haemolyticus (8, Staphylococcus saprophyticus (3, Staphylococcus cohnii (1, Staphylococcus auricularis (1, and 3 strains that were not identified at species level. Methicillin resistance was encountered in 53.40% of Staphylococcus aureus strains and in 80% of coagulase-negative staphylococci. Conclusions: An important percentage of blood cultures were contaminated with Staphylococcus species. The main species identified in true bacteriemia cases were Staphylococcus aureus and Staphylococcus epidermidis. The percentage of methicillin-resistance, proved to be high not only for coagulase-negative staphylococci but also for Staphylococcus aureus.

  7. Multifaceted antibiotic treatment analysis of methicillin-sensitive Staphylococcus aureus bloodstream infections.

    Science.gov (United States)

    Weber, Zhanni; Ariano, Robert; Lagacé-Wiens, Philippe; Zelenitsky, Sheryl

    2016-12-01

    Given the overall prevalence and poor prognosis of Staphylococcus aureus bloodstream infections (BSIs), the study of treatment strategies to improve patient outcomes is important. The aim of this study was to conduct a multifaceted antibiotic treatment analysis of methicillin-sensitive S. aureus (MSSA) BSI and to characterise optimal early antibiotic therapy (within the first 7 days of drawing the index blood culture) for this serious infection. Antibiotic selection was categorised as optimal targeted (intravenous cloxacillin or cefazolin), optimal broad (piperacillin/tazobactam or meropenem), adequate (vancomycin) or inadequate (other antibiotics or oral therapy). A TSE (timing, selection, exposure) score was developed to comprehensively characterise early antibiotic therapy, where higher points corresponded to prompt initiation, optimal antibiotic selection and longer exposure (duration). Amongst 71 cases of complicated MSSA-BSI, end-of-treatment (EOT) response (i.e. clinical cure) was improved when at least adequate antibiotic therapy was initiated within 24 h [71.7% (33/46) vs. 48.0% (12/25); P = 0.047]. Clinical cure was also more likely when therapy included ≥4 days of optimal targeted antibiotics within the first 7 days [74.4% (29/39) vs. 50.0% (16/32); P = 0.03]. The TSE score was an informative index of early antibiotic therapy, with EOT cure documented in 72.0% (36/50) compared with 42.9% (9/21) of cases with scores above and below 15.2, respectively (P = 0.02). In multivariable analysis, lower Charlson comorbidity index, presence of BSI on admission, and optimising early antibiotic therapy, as described above, were associated with clinical cure in patients with MSSA-BSI. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  8. Trends in Nosocomial Bloodstream Infections in a Burn Intensive Care Unit: an Eight-Year Survey

    Science.gov (United States)

    Zorgani, A.; Franka, R.A.; Zaidi, M.M.; Alshweref, U.M.; Elgmati, M.

    2010-01-01

    Summary This study was designed to evaluate the frequency and profile of bloodstream infection (BSI) in a burn intensive care unit (BICU) in Tripoli, Libya, from 1st January 2000 to 31st December 2007 and to determine the prevalence of different bacteria involved in such infections and their antimicrobial susceptibilities. During the eight-year study period, 995 patients were admitted to the BICU. Blood cultures were collected from each septicaemic case and reviewed for age, sex, total body surface area burned, isolated micro-organisms, and antibiotic sensitivity. There were 430 episodes of BSI among 830 cases; the annual true positive rate varied between 40.0 and 59.4%, the majority (87.9%) being caused by one species only. However, 22% had two or more episodes with different pathogens during hospitalization. The leading isolate was Staphylococcus aureus (40.4%) (methicillinresistant, 55.7%). Pseudomonas spp ranked second (23.9%). Klebsiella spp were third, responsible for 7.4%; the rate of extended spectrum beta lactamase among Klebsiella isolates was 47%. Candida spp were the fourth most common pathogen (6.7%), the majority (55%) being C. albicans. Staphylococci were generally resistant to trimethoprim (91%) and fusidic acid (80%). Pseudomonas spp proved moderately resistant (38-43%) to tobramicin, ciprofloxacin, amikacin, and impenem but remained relatively susceptible to cefepime (72%). Klebsiella isolates demonstrated moderate resistance (46-58%) to most agents tested, and relatively low resistance (19-27%) to meropenem, impenem, and cefepime. We suggest that extra infection control measures should be implemented and antibiotic policy and guidelines introduced to reduce the high resistance rate among isolates such as Pseudomonas, Acinetobacter, and MRSA. PMID:21991204

  9. Case-crossover study of Burkholderia cepacia complex bloodstream infection associated with contaminated intravenous bromopride.

    Science.gov (United States)

    Martins, Ianick Souto; Pellegrino, Flávia Lúcia Piffano Costa; Freitas, Andrea d'Avila; Santos, Marisa da Silva; Ferraiuoli, Giovanna Ianini d'Alemeida; Vasques, Márcia Regina Guimarães; Amorim, Efigenia Lourdes Teixeira; Oliveira, Sandra; Nouér, Simone Aranha; Cardoso, Fernando Luiz Lopes; Mascarenhas, Luiz Affonso; Magalhães, Ana Cristina Gouveia; Cleinman, Isabella Barbosa; Figueiredo, Agnes Marie Sá; Moreira, Beatriz Meurer

    2010-05-01

    To investigate an outbreak of healthcare-associated Burkholderia cepacia complex (BCC) primary bloodstream infections (BCC-BSI). Case-crossover study in a public hospital, a university hospital and a private hospital in Rio de Janeiro, Brazil, from March 2006 to May 2006. Twenty-five patients with BCC-BSI. After determining the date BCC-BSI symptoms started for each patient, 3 time intervals of data collection were defined, each one with a duration of 3 days: the case period, starting just before BCC-BSI symptoms onset; the control period, starting 6 days before BCC-BSI symptoms onset; and the washout period, comprising the 3 days between the case period and the control period. Exposures evaluated were intravascular solutions and invasive devices and procedures. Potential risk factors were identified by using the McNemar chi(2) adjusted test. Cultures of samples of potentially contaminated solutions were performed. BCC strain typing was performed by pulsed-field gel electrophoresis using SpeI. The statistical analysis revealed that the use of bromopride and dipyrone was associated with BCC-BSI. A total of 21 clinical isolates from 17 (68%) of the 25 patients and an isolate obtained from the bromopride vial were available for strain typing. Six pulsotypes were detected. A predominant pulsotype (A) accounted for 11 isolates obtained from 11 patients (65%) in the 3 study hospitals. Our investigation, using a case-crossover design, of an outbreak of BCC-BSI infections concluded it was polyclonal but likely caused by infusion of contaminated bromopride. The epidemiological finding was validated by microbiological analysis. After recall of contaminated bromopride vials by the manufacturer, the outbreak was controlled.

  10. Diversity of β-lactamases produced by imipenem resistant, Pseudomonas aeruginosa isolates from the bloodstream.

    Science.gov (United States)

    Najar Peerayeh, Shahin; Pirhajati Mahabadi, Rahim; Pakbaten Toupkanlou, Sanaz; Siadat, Seyed Davar

    2014-11-01

    The emergence of imipenem non-susceptible Pseudomonas aeruginosa isolates is a matter of great concern because these isolates can become resistant to all available antibiotics. This study conducted to characterize β-lactamase genes in imipenem resistant P. aeruginosa isolates from bloodstream. 56 non-duplicate clinical isolates of P. aeruginosa were collected in Tehran hospitals. Antibacterial susceptibility was determined by disk diffusion and MIC methods. ESBL and MBL production was confirmed by combined disk. β-Lactamase classes A, B and D genes were identified by PCR. Seventeen (30.3%) isolates were imipenem resistant for which 16 isolates simultaneously were resistant to all tested antibiotics. While among 39 imipenem susceptible isolates, only two isolates were resistant to all tested antibiotics. In imipenem resistant isolates, blaTEM, blaSHV and blaOXA-10 were found in 41.1% of isolates and blaVIM, blaIMP and blaPER were identified in 47%, 11.7% and 5.8% of isolates respectively, while in imipenem susceptible isolates, blaTEM, blaSHV and blaOXA-10 were determined in 2.5%, 7.6% and 33.3% of isolates, respectively. The imipenem resistant isolates had been recovered mostly (67.7%) from patients in the Burn hospital. The result of this study indicated the emergence of multidrug resistant MBL and non-MBL producing P. aeruginosa, particularly in the Burn hospital and blaVIM was dominant β-lactamase genes in imipenem resistant isolates. The isolation of carrier patients may lead to prevent a further dissemination. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  11. Bacillus Cereus catheter related bloodstream infection in a patient in a patient with acute lymphblastic leukemia

    Directory of Open Access Journals (Sweden)

    Lütfiye Öksüz

    2012-01-01

    Full Text Available

    Bacillus cereus infection is rarely associated with actual infection and for this reason single positive blood culture is usually regarded as contamination . However it may cause a number of infections, such catheter-related blood stream infections. Significant catheter-related bloodstream infections (CRBSI caused by Bacillus spp. are mainly due to B.cereus and have been predominantly reported in immunocompromised hosts1 . Catheter removal is generally advised for management of infection. In this report, catheter-related bacteremia caused by B.cereus in a patient with acute lymphoblastıc leukemia (ALL in Istanbul Medical Faculty was presented.A 44-year old man presented with fatigue, weight loss, epistaxis and high fever. A double-lumen Hickman–catheter (Bard 12.0 Fr, Round Dual Lumen was inserted by surgical cut-down to access the right subclavian vein which would be necessary for allogeneic stem cell transplantation. Three weeks later the patient presented with high fever and headache. Bacillus spp. was isolated from the cathether while blood culture obtained from the peripheral vein remained negative. The bacterial identification was confirmed as B.cereus using VITEK identification system

    It has been reported Bacillus cereus septicemia may be fatal in immunocompromised hosts despite broad-spectrum appropriate treatment10. Catheter removal is essential for prevention of recurrent bacteremia. Long-term cathater salvage should be reserved for appropriate patient group.

  12. Klebsiella pneumoniae bloodstream infections in neonates in a hospital in the Kingdom of Saudi Arabia.

    Science.gov (United States)

    Al-Rabea, A A; Burwen, D R; Eldeen, M A; Fontaine, R E; Tenover, F; Jarvis, W R

    1998-09-01

    To identify risk factors for Klebsiella pneumoniae bloodstream infections (BSI) in neonates in a hospital in the Kingdom of Saudi Arabia (KSA). Two case-control studies among hospitalized neonates during February 15-May 14, 1991, and a procedural and microbiological investigation. Hospital A, a maternity and children's hospital in KSA. Case patients had a blood culture positive for K pneumoniae after >2 days of hospitalization and had no evidence of a nonblood primary site of infection. When the 20 case patients were compared with controls, hospitalization in a critical-care unit (odds ratio [OR], 5.5; 95% confidence interval [CI95], 1.20-51.1; P=.03) was identified as a risk factor. When the case patients were compared with a second set of controls matched by critical-care status, receipt of a particular intravenous fluid (D10%/0.2NS; OR, 11.0; CI95, 1.42-85.2; P=.009) or a blood product (OR undefined; P=.04) were identified as risk factors. Infusates were administered via umbilical catheters for most case and control patients (19/20 vs 15/20, P>.05); catheters were manipulated more frequently in patients in critical-care units. Umbilical catheter tip, skin, or mucus membrane K pneumoniae colonization occurred in 47% and 53% of evaluated case and control patients, respectively. Available K pneumoniae isolates from blood cultures and colonization sites had identical antimicrobial susceptibility patterns. Emphasis on handwashing, careful preparation and administration of infusates, and aseptic technique for catheter insertion, maintenance, and manipulation was temporally associated with resolution of the epidemic. This outbreak was probably due to infusion therapy practices that led to BSI in nursery patients colonized with K pneumoniae. Both catheter-related infections and extrinsic contamination of infusates may have occurred. Hospital personnel should be aware of their potential to spread nosocomial pathogens from person to person and should implement Centers for

  13. Outbreak of Serratia marcescens bloodstream infections in patients receiving parenteral nutrition prepared by a compounding pharmacy.

    Science.gov (United States)

    Gupta, Neil; Hocevar, Susan N; Moulton-Meissner, Heather A; Stevens, Kelly M; McIntyre, Mary G; Jensen, Bette; Kuhar, David T; Noble-Wang, Judith A; Schnatz, Rick G; Becker, Shawn C; Kastango, Eric S; Shehab, Nadine; Kallen, Alexander J

    2014-07-01

    Compounding pharmacies often prepare parenteral nutrition (PN) and must adhere to rigorous standards to avoid contamination of the sterile preparation. In March 2011, Serratia marcescens bloodstream infections (BSIs) were identified in 5 patients receiving PN from a single compounding pharmacy. An investigation was conducted to identify potential sources of contamination and prevent further infections. Cases were defined as S. marcescens BSIs in patients receiving PN from the pharmacy between January and March 2011. We reviewed case patients' clinical records, evaluated pharmacy compounding practices, and obtained epidemiologically directed environmental cultures. Molecular relatedness of available Serratia isolates was determined by pulsed-field gel electrophoresis (PFGE). Nineteen case patients were identified; 9 died. The attack rate for patients receiving PN in March was 35%. No case patients were younger than 18 years. In October 2010, the pharmacy began compounding and filter-sterilizing amino acid solution for adult PN using nonsterile amino acids due to a national manufacturer shortage. Review of this process identified breaches in mixing, filtration, and sterility testing practices. S. marcescens was identified from a pharmacy water faucet, mixing container, and opened amino acid powder. These isolates were indistinguishable from the outbreak strain by PFGE. Compounding of nonsterile amino acid components of PN was initiated due to a manufacturer shortage. Failure to follow recommended compounding standards contributed to an outbreak of S. marcescens BSIs. Improved adherence to sterile compounding standards, critical examination of standards for sterile compounding from nonsterile ingredients, and more rigorous oversight of compounding pharmacies is needed to prevent future outbreaks. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public

  14. The Changing Epidemiology of Bloodstream Infections and Resistance in Hematopoietic Stem Cell Transplantation Recipients

    Directory of Open Access Journals (Sweden)

    Mücahit Yemişen

    2016-08-01

    Full Text Available Objective: Patients receiving hematopoietic stem cell transplantation (HSCT are exposed to highly immunosuppressive conditions and bloodstream infections (BSIs are one of the most common major complications within this period. Our aim, in this study, was to evaluate the epidemiology of BSIs in these patients retrospectively. Materials and Methods: The epidemiological properties of 312 patients with HSCT were retrospectively evaluated. Results: A total of 312 patients, followed between 2000 and 2011, who underwent autologous (62% and allogeneic (38% HSCT were included in the study. The most common underlying malignancies were multiple myeloma (28% and Hodgkin lymphoma (21.5%. A total of 142 (45% patients developed at least 1 episode of BSI and 193 separate pathogens were isolated from the blood cultures. There was a trend of increase in the numbers of BSIs in 2005-2008 and a relative increase in the proportion of gram-positive infections in recent years (2009-2011, and central venous catheter-related BSI was found to be most common source. Coagulase-negative staphylococci (49.2% and Acinetobacter baumannii (8.8% were the most common pathogens. Extended-spectrum beta-lactamase-producing strains were 23% and 22% among Escherichia coli and Klebsiella spp. isolates, respectively. Quinolone resistance was detected in 10% of Enterobacteriaceae. Resistance to carbapenems was not detected in Enterobacteriaceae, while it was seen at 11.1% and 23.5% in Pseudomonas and Acinetobacter strains, respectively. Conclusion: A shift was detected from gram-negative bacteria to gram-positive in the etiology over the years and central lines were the most common sources of BSIs.

  15. Risk factors and mortality for nosocomial bloodstream infections in elderly patients.

    Science.gov (United States)

    Reunes, S; Rombaut, V; Vogelaers, D; Brusselaers, N; Lizy, C; Cankurtaran, M; Labeau, S; Petrovic, M; Blot, S

    2011-10-01

    To determine risk factors for nosocomial bloodstream infection (BSI) and associated mortality in geriatric patients in geriatric and internal medicine wards at a university hospital. Single-center retrospective (1992-2007), pairwise-matched (1:1-ratio) cohort study. Geriatric patients with nosocomial BSI were matched with controls without BSI on year of admission and length of hospitalization before onset of BSI. Demographic, microbiological, and clinical data are collected. One-hundred forty-two BSI occurred in 129 patients. Predominant microorganisms were Escherichia coli (23.2%), coagulase-negative Staphylococci (19.4%), Pseudomonas aeruginosa (8.4%), Staphylococcus aureus (7.1%), Klebsiella pneumoniae (5.8%) and Candida spp. (5.8%). Matching was successful for 109 cases. Compared to matched control subjects, cases were more frequently female, suffered more frequently from arthrosis, angina pectoris and pressure ulcers, had worse Activities of Daily Living-scores, had more often an intravenous or bladder catheter, and were more often bedridden. Logistic regression demonstrated presence of an intravenous catheter (odds ratio [OR] 7.5, 95% confidence interval [CI] 2.5-22.9) and being bedridden (OR 2.9, 95% CI 1.6-5.3) as independent risk factors for BSI. In univariate analysis nosocomial BSI was associated with increased mortality (22.0% vs. 11.0%; P=0.029). After adjustment for confounding co-variates, however, nosocomial BSI was not associated with mortality (hazard ratio 1.3, 95% CI 0.6-2.6). Being bedridden and increasing age were independent risk factors for death. Intravenous catheters and being bedridden are the main risk factors for nosocomial BSI. Although associated with higher mortality, this infectious complication seems not to be an independent risk factor for death in geriatric patients. Copyright © 2011 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  16. Validation of a Sampling Method to Collect Exposure Data for Central-Line-Associated Bloodstream Infections.

    Science.gov (United States)

    Hammami, Naïma; Mertens, Karl; Overholser, Rosanna; Goetghebeur, Els; Catry, Boudewijn; Lambert, Marie-Laurence

    2016-05-01

    Surveillance of central-line-associated bloodstream infections requires the labor-intensive counting of central-line days (CLDs). This workload could be reduced by sampling. Our objective was to evaluate the accuracy of various sampling strategies in the estimation of CLDs in intensive care units (ICUs) and to establish a set of rules to identify optimal sampling strategies depending on ICU characteristics. Analyses of existing data collected according to the European protocol for patient-based surveillance of ICU-acquired infections in Belgium between 2004 and 2012. CLD data were reported by 56 ICUs in 39 hospitals during 364 trimesters. We compared estimated CLD data obtained from weekly and monthly sampling schemes with the observed exhaustive CLD data over the trimester by assessing the CLD percentage error (ie, observed CLDs - estimated CLDs/observed CLDs). We identified predictors of improved accuracy using linear mixed models. When sampling once per week or 3 times per month, 80% of ICU trimesters had a CLD percentage error within 10%. When sampling twice per week, this was >90% of ICU trimesters. Sampling on Tuesdays provided the best estimations. In the linear mixed model, the observed CLD count was the best predictor for a smaller percentage error. The following sampling strategies provided an estimate within 10% of the actual CLD for 97% of the ICU trimesters with 90% confidence: 3 times per month in an ICU with >650 CLDs per trimester or each Tuesday in an ICU with >480 CLDs per trimester. Sampling of CLDs provides an acceptable alternative to daily collection of CLD data.

  17. Sustained Reduction in Bloodstream Infections in Infants at a Large Tertiary Care Neonatal Intensive Care Unit

    Science.gov (United States)

    Neill, Sara; Haithcock, Sarah; Smith, P. Brian; Goldberg, Ronald; Bidegain, Margarita; Tanaka, David; Carriker, Charlene; Ericson, Jessica E.

    2015-01-01

    Purpose Reduction of bloodstream infections (BSI) has emerged as an important patient safety goal. Implementation of central line insertion bundles, standardized line care protocols, and health care provider education programs have reduced BSI in neonatal intensive care units (NICUs) around the country. The ability of large tertiary care centers to decrease nosocomial infections, including BSI, has been demonstrated. However, long-term BSI reductions in infants are not well documented. We sought to demonstrate that a low incidence of BSI can be maintained over time in a tertiary care NICU. Subjects 6,790 infants admitted to a large, tertiary care NICU between 2005 and 2013. Design Retrospective intervention study. Methods A staged, multifaceted infection prevention plan was implemented beginning in October 2007 under nursing leadership. The incidence of BSI was determined annually for 2005-2013. Results Baseline BSI incidence for infants admitted to the NICU was 5.15 and 6.08 episodes per 1,000 infant-days in 2005 and 2006, respectively. After protocol implementation, the incidence of BSI decreased to 2.14/1,000 infant-days and 2.44/1,000 infant-days in 2008 and 2009, respectively. Yearly incidence remained low over the next 4 years and decreased even further to 0.20-0.45 infections/1,000 infant days. This represents a 92% decrease in BSI over a period of >5 years. Conclusions Implementation of a nursing-led comprehensive infection control initiative can effectively produce and maintain a reduction in the incidence of BSI in infants at a large tertiary care NICU. What this study adds Long term reductions in neonatal BSI are possible with implementation of a multidisciplinary team approach and strong nursing leadership. PMID:25915573

  18. Support for higher ciprofloxacin AUC 24/MIC targets in treating Enterobacteriaceae bloodstream infection.

    Science.gov (United States)

    Zelenitsky, Sheryl A; Ariano, Robert E

    2010-08-01

    Given concerns regarding optimal therapy for serious Gram-negative infections, the goal was to characterize the pharmacodynamics of ciprofloxacin in the context of treating bloodstream infection. Data were collected from the medical records of 178 clinical cases. Blood isolates were retrieved and ciprofloxacin MICs were measured. Forty-two cases in which ciprofloxacin was initiated within 24 h of the positive blood culture were used in the pharmacodynamic analysis. Significant factors with regard to treatment failure were low ciprofloxacin AUC(24)/MIC (P AUC(24) (P = 0.01). AUC(24)/MIC (P = 0.012) and MIC (P = 0.019) were significant variables in multivariate analyses; however, only the former remained significant (P = 0.038) after excluding two cases with ciprofloxacin-resistant isolates. An AUC(24)/MIC breakpoint of 250 was most significant, with cure rates of 91.4% (32/35) and 28.6% (2/7) in patients with values above and below this threshold, respectively (P = 0.001). The risk of ciprofloxacin treatment failure was 27.8 times (95% confidence interval, 2.1-333) greater in those not achieving an AUC(24)/MIC >or=250 (P = 0.011). Monte Carlo simulation of 5000 study subjects predicted that 0.88 of the population would achieve an AUC(24)/MIC >or=250 with standard-dose ciprofloxacin (400 mg intravenously every 12 h). This study confirms the pharmacodynamic parameters of ciprofloxacin that are important for optimizing the treatment of serious infections, particularly the benefits of achieving an AUC(24)/MIC >or=250, rather than the conventional target of >or=125. It also shows the relevance of dose selection in optimizing target attainment, with important differences among pathogens, even those with MICs within the susceptible range.

  19. Effectiveness of oral antibiotics for definitive therapy of Gram-negative bloodstream infections.

    Science.gov (United States)

    Kutob, Leila F; Justo, Julie Ann; Bookstaver, P Brandon; Kohn, Joseph; Albrecht, Helmut; Al-Hasan, Majdi N

    2016-11-01

    There is paucity of data evaluating intravenous-to-oral antibiotic switch options for Gram-negative bloodstream infections (BSIs). This retrospective cohort study examined the effectiveness of oral antibiotics for definitive treatment of Gram-negative BSI. Patients with Gram-negative BSI hospitalised for antibiotics were included in this study. The cohort was stratified into three groups based on bioavailability of oral antibiotics prescribed (high, ≥95%; moderate, 75-94%; and low, antibiotics were prescribed to 106, 179 and 77 patients, respectively, for definitive therapy of Gram-negative BSI. Mean patient age was 63 years, 217 (59.9%) were women and 254 (70.2%) had a urinary source of infection. Treatment failure rates were 2%, 12% and 14% in patients receiving oral antibiotics with high, moderate and low bioavailability, respectively (P = 0.02). Risk of treatment failure in the multivariate Cox model was higher in patients receiving antibiotics with moderate [adjusted hazard ratio (aHR) = 5.9, 95% CI 1.6-38.5; P = 0.005] and low bioavailability (aHR = 7.7, 95% CI 1.9-51.5; P = 0.003) compared with those receiving oral antimicrobial agents with high bioavailability. These data demonstrate the effectiveness of oral antibiotics with high bioavailability for definitive therapy of Gram-negative BSI. Risk of treatment failure increases as bioavailability of the oral regimen declines. Copyright © 2016 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  20. Is Clostridium difficile infection a risk factor for subsequent bloodstream infection?

    Science.gov (United States)

    Ulrich, Robert J; Santhosh, Kavitha; Mogle, Jill A; Young, Vincent B; Rao, Krishna

    2017-12-01

    Clostridium difficile infection (CDI) is a common nosocomial diarrheal illness increasingly associated with mortality in United States. The underlying factors and mechanisms behind the recent increases in morbidity from CDI have not been fully elucidated. Murine models suggest a mucosal barrier breakdown leads to bacterial translocation and subsequent bloodstream infection (BSI). This study tests the hypothesis that CDI is associated with subsequent BSI in humans. We conducted a retrospective cohort study on 1132 inpatients hospitalized >72 h with available stool test results for toxigenic C. difficile. The primary outcome was BSI following CDI. Secondary outcomes included 30-day mortality, colectomy, readmission, and ICU admission. Unadjusted and adjusted logistic regression models were developed. CDI occurred in 570 of 1132 patients (50.4%). BSI occurred in 86 (7.6%) patients. Enterococcus (14%) and Klebsiella (14%) species were the most common organisms. Patients with BSI had higher comorbidity scores and were more likely to be male, on immunosuppression, critically ill, and have a central venous catheter in place. Of the patients with BSI, 36 (42%) had CDI. CDI was not associated with subsequent BSI (OR 0.69; 95% CI 0.44-1.08; P = 0.103) in unadjusted analysis. In multivariable modeling, CDI appeared protective against subsequent BSI (OR 0.57; 95% CI 0.34-0.96; P = 0.036). Interaction modeling suggests a complicated relationship among CDI, BSI, antibiotic exposure, and central venous catheter use. In this cohort of inpatients that underwent testing for CDI, CDI was not a risk factor for developing subsequent BSI. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Neonatal Escherichia coli Bloodstream Infections: Clinical Outcomes and Impact of Initial Antibiotic Therapy.

    Science.gov (United States)

    Bergin, Stephen P; Thaden, Joshua T; Ericson, Jessica E; Cross, Heather; Messina, Julia; Clark, Reese H; Fowler, Vance G; Benjamin, Daniel K; Hornik, Christoph P; Smith, P Brian

    2015-09-01

    Escherichia coli is a common cause of bloodstream infections (BSIs) in infants and is associated with high mortality and morbidity among survivors. The clinical significance of antibiotic resistance and timing of appropriate antimicrobial therapy in this population is poorly understood. We identified all infants with E. coli BSIs discharged from 77 neonatal intensive care units managed by the Pediatrix Medical Group in 2012. We used multivariable logistic regression to evaluate the association between 30-day mortality and ampicillin-resistant E. coli BSI, as well as the number of active empiric antimicrobial agents administered, controlling for gestational age, small-for-gestational age status, early-onset versus late-onset BSI, oxygen requirement, ventilator support and inotropic support on the day of the first positive blood culture. We identified 258 episodes of E. coli BSI, including 123 (48%) ampicillin-resistant isolates. Unadjusted 30-day mortality did not significantly differ between infants with ampicillin-resistant versus ampicillin-susceptible E. coli BSI [11 of 123 (9%) vs. 7 of 135 (5%); P = 0.33; adjusted odds ratio = 1.37 (95% confidence interval: 0.39, 4.77)]. Among ampicillin-resistant E. coli BSIs, 30-day mortality was not significantly lower for infants treated with at least one empiric antimicrobial active against ampicillin-resistant E. coli versus infants receiving no active empiric agent [adjusted odds ratio = 1.50 (0.07, 33.6)]. In this population of infants with E. coli BSI, ampicillin resistance was not associated with significantly increased mortality. Among the subset of infants with ampicillin-resistant E. coli, appropriate empirical antibiotic therapy was not associated with lower mortality.

  2. Characterising health care-associated bloodstream infections in public hospitals in Queensland, 2008-2012.

    Science.gov (United States)

    Si, Damin; Runnegar, Naomi; Marquess, John; Rajmokan, Mohana; Playford, Elliott G

    2016-04-18

    To describe the epidemiology and rates of all health care-associated bloodstream infections (HA-BSIs) and of specific HA-BSI subsets in public hospitals in Queensland. Standardised HA-BSI surveillance data were collected in 23 Queensland public hospitals, 2008-2012. HA-BSIs were prospectively classified in terms of place of acquisition (inpatient, non-inpatient); focus of infection (intravascular catheter-associated, organ site focus, neutropenic sepsis, or unknown focus); and causative organisms. Inpatient HA-BSI rates (per 10,000 patient-days) were calculated. There were 8092 HA-BSIs and 9418 causative organisms reported. Inpatient HA-BSIs accounted for 79% of all cases. The focus of infection in 2792 cases (35%) was an organ site, intravascular catheters in 2755 (34%; including 2240 central line catheters), neutropenic sepsis in 1063 (13%), and unknown in 1482 (18%). Five per cent (117 of 2240) of central line-associated BSIs (CLABSIs) were attributable to intensive care units (ICUs). Eight groups of organisms provided 79% of causative agents: coagulase-negative staphylococci (18%), Staphylococcus aureus (15%), Escherichia coli (11%), Pseudomonas species (9%), Klebsiella pneumoniae/oxytoca (8%), Enterococcus species (7%), Enterobacter species (6%), and Candida species (5%). The overall inpatient HA-BSI rate was 6.0 per 10,000 patient-days. The rates for important BSI subsets included: intravascular catheter-associated BSIs, 1.9 per 10,000 patient-days; S. aureus BSIs, 1.0 per 10,000 patient-days; and methicillin-resistant S. aureus BSIs, 0.3 per 10,000 patient-days. The rate of HA-BSIs in Queensland public hospitals is lower than reported by similar studies elsewhere. About one-third of HA-BSIs are attributable to intravascular catheters, predominantly central venous lines, but the vast majority of CLABSIs are contracted outside ICUs. Different sources of HA-BSIs require different prevention strategies.

  3. Tigecycline activity tested against 26,474 bloodstream infection isolates: a collection from 6 continents.

    Science.gov (United States)

    Sader, Helio S; Jones, Ronald N; Stilwell, Matthew G; Dowzicky, Michael J; Fritsche, Thomas R

    2005-07-01

    The activity of tigecycline (formerly GAR936), a novel glycylcycline, was tested against recent bloodstream infection (BSI) pathogen isolates from 6 continents. Frequency of clinical occurrence of these pathogens was determined and their antibiograms assessed using reference broth microdilution methods. A total of 26474 strains were tested for tigecycline susceptibility according to the Clinical and Laboratory Standards Institute (formerly the National Committee for Clinical Laboratory Standards) by the M7-A6 guidelines with interpretations from M100-S15 and the package insert. The rank order of pathogens was Staphylococcus aureus (33.1%), Escherichia coli (14.0%), coagulase-negative staphylococci (13.5%), Enterococcus spp. (12.3%), Klebsiella spp. (5.7%), Pseudomonas aeruginosa (4.2%), Enterobacter spp. (3.0%), beta-hemolytic streptococci (2.9%), Streptococcus pneumoniae (2.3%), and viridans group streptococci (1.4%). Tigecycline exhibited a broader spectrum of activity against BSI isolates when compared to ciprofloxacin, tetracycline, aminoglycosides, and many beta-lactams (imipenem). Tigecycline was highly active against most pathogens tested, including staphylococci (MIC(90), 0.5 microg/mL), enterococci (MIC90, 0.25 microg/mL), streptococci (MIC(90), < or =0.12 microg/mL), Escherichia coli (MIC90, 0.25 microg/mL), Klebsiella spp. (MIC90, 1 mmicrog/mL), and Enterobacter spp. (MIC(90), 2 mmicrog/mL), but showed limited inhibition of Pseudomonas aeruginosa (MIC90, 16 microg/mL) and indole-positive or indole-negative Proteae (MIC90, 4-8 microg/mL). In summary, tigecycline exhibited a wide spectrum of antimicrobial potency versus BSI isolates collected worldwide. Serious infections in nosocomial environments should benefit from tigecycline use among the investigational phase 3 agents focused toward resistant strains.

  4. Bloodstream infection following 217 consecutive systemic-enteric drained pancreas transplants

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    Mark Walter

    2006-08-01

    Full Text Available Abstract Background Combined kidney pancreas transplantation (PTx evolved as excellent treatment for diabetic nephropathy. Infections remain common and serious complications. Methods 217 consecutive enteric drained PTxs performed from 1997 to 2004 were retrospectively analyzed with regard to bloodstream infection. Immunosuppression consisted of antithymocyteglobuline induction, tacrolimus, mycophenolic acid and steroids for the majority of cases. Standard perioperative antimicrobial prophylaxis consisted of pipercillin/tazobactam in combination with ciprofloxacin and fluconazole. Results One year patient, pancreas and kidney graft survival were 96.4%, 88.5% and 94.8%, surgical complication rate was 35%, rejection rate 30% and rate of infection 59%. In total 46 sepsis episodes were diagnosed in 35 patients (16% with a median onset on day 12 (range 1–45 post transplant. Sepsis source was intraabdominal infection (IAI (n = 21, a contaminated central venous line (n = 10, wound infection (n = 5, urinary tract infection (n = 2 and graft transmitted (n = 2. Nine patients (4% experienced multiple episodes of sepsis. Overall 65 pathogens (IAI sepsis 39, line sepsis 15, others 11 were isolated from blood. Gram positive cocci accounted for 50 isolates (77%: Coagulase negative staphylococci (n = 28, i.e. 43% (nine multi-resistant, Staphylococcus aureus (n = 11, i.e. 17% (four multi-resistant, enterococci (n = 9, i.e. 14% (one E. faecium. Gram negative rods were cultured in twelve cases (18%. Patients with blood borne infection had a two year pancreas graft survival of 76.5% versus 89.4% for those without sepsis (p = 0.036, patient survival was not affected. Conclusion Sepsis remains a serious complication after PTx with significantly reduced pancreas graft, but not patient survival. The most common source is IAI.

  5. Molecular epidemiology and antimicrobial resistance of methicillin-resistant Staphylococcus aureus bloodstream isolates in Taiwan, 2010.

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    Chih-Jung Chen

    Full Text Available The information of molecular characteristics and antimicrobial susceptibility pattern of methicillin-resistant Staphylococcus aureus (MRSA is essential for control and treatment of diseases caused by this medically important pathogen. A total of 577 clinical MRSA bloodstream isolates from six major hospitals in Taiwan were determined for molecular types, carriage of Panton-Valentine leukocidin (PVL and sasX genes and susceptibilities to 9 non-beta-lactam antimicrobial agents. A total of 17 genotypes were identified in 577 strains by pulsotyping. Five major pulsotypes, which included type A (26.2%, belonging to sequence type (ST 239, carrying type III staphylococcal chromosomal cassette mec (SCCmec, type F (18.9%, ST5-SCCmecII, type C (18.5%, ST59-SCCmecIV, type B (12.0%, ST239-SCCmecIII and type D (10.9%, ST59-SCCmecVT/IV, prevailed in each of the six sampled hospitals. PVL and sasX genes were respectively carried by ST59-type D strains and ST239 strains with high frequencies (93.7% and 99.1%, respectively but rarely detected in strains of other genotypes. Isolates of different genotypes and from different hospitals exhibited distinct antibiograms. Multi-resistance to ≥3 non-beta-lactams was more common in ST239 isolates (100% than in ST5 isolates (97.2%, P = 0.0347 and ST59 isolates (8.2%, P<0.0001. Multivariate analysis further indicated that the genotype, but not the hospital, was an independent factor associated with muti-resistance of the MRSA strains. In conclusion, five common MRSA clones with distinct antibiograms prevailed in the major hospitals in Taiwan in 2010. The antimicrobial susceptibility pattern of invasive MRSA was mainly determined by the clonal distribution.

  6. 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

  7. Second-Generation central venous catheter in the prevention of bloodstream infection: a systematic review.

    Science.gov (United States)

    Stocco, Janislei Gislei Dorociaki; Hoers, Hellen; Pott, Franciele Soares; Crozeta, Karla; Barbosa, Dulce Aparecida; Meier, Marineli Joaquim

    2016-08-08

    to evaluate the effectiveness and safety in the use of second-generation central venous catheters impregnated in clorhexidine and silver sulfadiazine when compared with other catheters, being them impregnated or not, in order to prevent the bloodstream infection prevention. systematic review with meta-analysis. Databases searched: MEDLINE, EMBASE, CINAHL, LILACS/SciELO, Cochrane CENTRAL; search in Congress Proceedings and records from Clinical Trials. 1.235 studies were identified, 97 were pre-selected and 4 were included. In catheter-related bloodstream infection, there was no statistical significance between second-generation impregnated catheter compared with the non-impregnated ones, absolute relative risk 1,5% confidence interval 95% (3%-1%), relative risk 0,68 (confidence interval 95%, 0,40-1,15) and number needed to treat 66. In the sensitivity analysis, there was less bloodstream infection in impregnated catheters (relative risk 0,50, confidence interval 95%, 0,26-0,96). Lower colonization, absolute relative risk 9,6% (confidence interval 95%, 10% to 4%), relative risk 0,51 (confidence interval 95% from 0,38-0,85) and number needed to treat 5. the use of second-generation catheters was effective in reducing the catheter colonization and infection when a sensitivity analysis is performed. Future clinical trials are suggested to evaluate sepsis rates, mortality and adverse effects. evaluar la efectividad y seguridad del uso de catéteres venosos centrales de segunda generación, impregnados en clorhexidina y sulfadiazina de plata, comparados con otros catéteres impregnados o no impregnados, para prevención de infección de la corriente sanguínea. revisión sistemática con metaanálisis. La búsqueda fue realizada en las bases: MEDLINE, EMBASE, CINAHL, LILACS/SciELO, Cochrane CENTRAL; fueron consultados anales de congresos y registros de ensayos clínicos. fueron identificados 1.235 estudios, 97 preseleccionados y cuatro incluidos. En la infección de la

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

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    Vanesa Olivares-Illana

    2007-10-01

    Full Text Available 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.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.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.

  9. Prevalencia de infeccion a Trypanosoma cruzi en donadores de sangre en el Estado de Jalisco, Mexico

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    Francisco Trujillo Contreras

    1993-06-01

    Full Text Available Durante el periodo de Octubre de 1991 a Marzo de 1992, se tomaron 3419 muestras de donadores de sangre de 12 localidades rurales y de 8 hospitales urbanos a los que se les realizo un estúdio serológico mediante la reacción de hemaglutinación indirecta encontrándose anticuerpos contra Trypanosoma cruzi en 44 indivíduos 39 masculinosy 5 femininos. El 90,9% de donantes fueron masculinos. De acuerdo a su procedencia, el 73,5% fué del área urbana y el 26,5% del área rural. De acuerdo a los resultados el riesgo de transmisión de T. cruzi por transfusión sanguinea está latente por la creciente urbanización de la enfermedad de Chagas.A Chagas Disease serological study was done frorn October 1991 to March 1992 and 3419 samples were takenfrom people who donated blood at 12 county areas of Jalisco, México and 8 urban hospitais, by means of indirect hemagglutination reaction. The results indicate that: 73.5% of the donors were from urban area, 26.5% were from rural areas; 1.28% of the donors (N=44 were considered infected. Thirty nine of them (1.14 were males and 5 females. According to the above mentioned data, we can confirm that the risk of transmission of Trypanosoma cruzi can occur by blood transfusion and this is potentially latent because of the growing urbanization of Chagas disease.

  10. 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.

  11. MECHANISMS OF RESISTANCE TO ANTIPARASITIC DRUGS IN TRYPANOSOMA CRUZI. CORRELATIONS BETWEEN GENOTYPE AND RESISTANCE

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    John M Kelly

    2013-01-01

    Full Text Available El benznidazol y el nifurtimux conpuestos nitroheterocilicos son los medicamentos aprobados para el tratamiento de las infecciones por Trypanosoma cruzi. Ambos son profármacos y no tienen importantes propiedades tripanocidas hasta su activación intraparasitaria. La enzima responsable es una nitroreductasa (TcNTR , que inicia una cascada reductora que conduce a la generación de los metabolitos tóxicos que matan al parásito. Los procesos que actúan para regular a esta enzima conducen a la resis- tencia cruzada contra ambos fármacos. Estos incluyen la pérdida de uno de los cromosomas que contienen el gen TcNTR o mutaciones puntuales que inactivan la enzima. Los parásitos TcNTR heterocigotos son infecciosos, no muestran un fenotipo nocivo obvio y son hasta 5 veces más resistente a benznidazol y el nifurtimox. Sin embargo, la pérdida completa de la actividad TcNTR hace que T. cruzi no sea infeccioso, lo que sugiere que puede haber un límite para el nivel de resistencia por este mecanismo. En las poblaciones naturales de T. cruzi no se encontraron pruebas de que las amplias variaciones en la sensibilidad al benznidazol estén vinculadas a las mutaciones en TcNTR lo que, junto con la evidencia de que la resistencia a benznidazol y nifurtimox no siempre es conjunta, indica que existen otros mecanismos independientes de TcNTR. Los nuevos avances en tecnología ofrecen la oportunidad de explorar más a fondo esta cuestión.

  12. Melatonin: Antioxidant and modulatory properties in age-related changes during Trypanosoma cruzi infection.

    Science.gov (United States)

    Brazão, Vânia; Santello, Fabricia H; Colato, Rafaela P; Mazotti, Tamires T; Tazinafo, Lucas F; Toldo, Míriam Paula A; do Vale, Gabriel T; Tirapelli, Carlos R; do Prado, José C

    2017-08-01

    The purpose of this study was to investigate the effects of melatonin on selected biomarkers of innate and humoral immune response as well as the antioxidant/oxidant status (superoxide dismutase-SOD and reduced glutathione levels (GSH) to understand whether age-related changes would influence the development of acute Trypanosoma cruzi (T. cruzi) infection. Young- (5 weeks) and middle-aged (18 months) Wistar rats were orally treated with melatonin (gavage) (05 mg/kg/day), 9 days after infection. A significant increase in both SOD activity and GSH levels was found in plasma from all middle-aged melatonin-treated animals. Melatonin triggered enhanced expression of major histocompatibility class II (MHC-II) antigens on antigen-presenting cell (APC) and peritoneal macrophages in all treated animals. High levels of CD4 + CD28-negative T cells (*PMelatonin induced a significant reduction (***PMelatonin also triggered an upregulation of CD80 and CD86 expression in all young-treated groups. Significant percentages of B and spleen dendritic cells in middle-aged infected and treated animals were observed. Our data reveal new features of melatonin action in inhibiting membrane lipid peroxidation, through the reduction in 8-isoprostane, upregulating the antioxidant defenses and triggering an effective balance in the antioxidant/oxidant status during acute infection. The ability of melatonin to counteract the immune alterations induced by aging added further support to its use as a potential therapeutic target not only for T. cruzi infection but also for other immunocompromised states. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Cellular immune response from Chagasic patients to CRA or FRA recombinant antigens of Trypanosoma cruzi.

    Science.gov (United States)

    Lorena, Virginia M B; Verçosa, Alinne F A; Machado, Raquel C A; Moitinho-Silva, Lucas; Cavalcanti, Maria G A; Silva, Edimilson D; Ferreira, Antonio G P; Correa-Oliveira, Rodrigo; Pereira, Valéria R A; Gomes, Yara M

    2008-01-01

    We propose to analyze the relation between the cellular immune response of Chagas' disease patients after in vitro stimulation of peripheral blood mononuclear cells (PBMC) with recombinant antigens cytoplasmatic repetitive antigen (CRA) or flagellar repetitive antigen (FRA) of T. cruzi and the chronic clinical forms of disease. Cells were stimulated using phytohemagglutinin, CRA, FRA, or a soluble antigen of Epimastigota (Ag-Epi) for 24 hr, 72 hr, or 6 days. The proliferation of cells was evaluated after 6 days of culture by quantification of incorporated 3H-thymidine. Cytokines were measured in the supernatants obtained after 24 hr (tumor necrosis factor [TNF]-alpha and interleukin [IL]-4), 72 hr (IL-10), and 6 days (interferon [IFN]-gamma) using enzyme-linked immunosorbent assay (ELISA). Cells of the Chagas patients stimulated with the recombinant antigens exhibited higher proliferation responses compared with that of non-Chagas (NC) individuals. However, when proliferation was compared between patients with the cardiac form (CF) or indeterminate form (IF), it was not possible to establish a difference in the response. So far as the cytokines secreted in the culture supernatants after stimulation in vitro with T. cruzi antigens were concerned, the results showed that CRA, as well as Epi-Ag, were able to stimulate the production of TNF-alpha and IFN-gamma in Chagas patients as compared with NC individuals. However, the cytokine levels after stimulation with the T. cruzi antigens were not different between the patients with CF and IF. CRA was capable of inducing a T helper type 1 (Th1) immune response, with elevated production of TNF-alpha and IFN-gamma in Chagas patients that are carriers of CF and IF clinical forms. (Copyright ) 2008 Wiley-Liss, Inc.

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

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    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.

  15. 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.

  16. 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

  17. Alternative Method for the Mass Rearing of Lutzomyia (Lutzomyia) cruzi (Diptera: Psychodidae) in a Laboratory Setting.

    Science.gov (United States)

    Oliveira, E F; Fernandes, W S; Oshiro, E T; Oliveira, A G; Galati, E A B

    2015-09-01

    The understanding of the transmission dynamics of Leishmania spp. Ross as well as the epidemiology and spread of leishmaniasis is related to parasite-vector-host interactions. These interactions can be studied using specimens of a sand fly population reared in the laboratory, exposing individuals to experimental infection for the investigation of vector competence and parameters of the vectorial capacity of the species. The present study sought to describe an alternative method for the implantation of a Lutzomyia (Lutzomyia) cruzi colony with wild specimens captured in the municipality of Corumbá, Brazil. With Method 1, engorged females were individualized for oviposition. The eggs were transferred to an acrylic petri dish with a layer of plaster on the bottom, on which food was placed after hatching of the first larvae. With Method 2, females were kept in groups for oviposition in containers, in which soil and food were placed on their bottom for the larvae. In addition, the exposure time of the larvae to light was reduced in comparison with Method 1. With Method 2, a significantly greater number of specimens of Lu. cruzi was obtained. The ratio between the number of emerged adults and the females followed for oviposition was 0.42 with Method 1 and 2.75 with Method 2. The optimization of the rearing conditions for Lu. cruzi will enable the establishment of a colony providing a sufficient number of specimens to develop experimental infection by Leishmania as well as vectorial competence and some parameters of the vectorial capacity of this sand fly. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Heterogeneities in the Ecoepidemiology of Trypanosoma cruzi Infection in Rural Communities of the Argentinean Chaco

    OpenAIRE

    Cardinal, M. Victoria; Orozco, M. Marcela; Enriquez, Gustavo F.; Ceballos, Leonardo A.; Gaspe, María Sol; Alvarado-Otegui, Julián A.; Gurevitz, Juan M.; Kitron, Uriel; Gürtler, Ricardo E.

    2014-01-01

    We conducted a cross-sectional survey of Trypanosoma cruzi infection of Triatoma infestans as well as dogs and cats in 327 households from a well-defined rural area in northeastern Argentina to test whether the household distribution of infection differed between local ethnic groups (Tobas and Creoles) and identify risk factors for host infection. Overall prevalence of infection of bugs (27.2%; 95% confidence interval = 25.3–29.3%), dogs (26.0%; 95% confidence interval = 23.3–30.1%), and cats...

  19. Sialoglycoconjugates in Trypanosoma cruzi-host cell interaction: possible biological model - a review

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    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.

  20. Influence of Trypanosoma cruzi strain on the pathogenesis of chronic myocardiopathy in mice

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    Sonia G. Andrade

    1990-03-01

    Full Text Available The murine model of chronic Chaga's myocardiopathy was developed in 201 inbred and outbred mice. The experimental groups consisted of 1st: 73 inbred AKR and A/J mice inoculated with one of the following. Trypanosoma cruzi strains: Peruvian (Type I, 12 SF (Type II or Colombian (Type III; 2nd: 128 outbred Swiss mice, chronically infected either with Type II or Type III strains isolated from human patients from different geographical areas. All T. cruzi strains were previoulsly characterized by their morphobiological behaviour in mice and by isoenzymatic patterns. For the 1st group the inoculum was 5 x 10**4 for the Peruvian strain and 1 x 10**5 for the 12 SF and Colombian strains. In the 2nd group-Swiss mice the inoculum size varied from 2 x 10**4 to 2 x 10**5. The inbred animals were killed at a 3 time-point scale (90, 180 and 240 days post-infection. The Swiss mice were killed from 180 to 660 days after infection. The evaluation of parasitemia and serology (xeodiagnosis and indirect immunofluorescent test was performed. The incidence of macroscopic alterations of the heart and cardiac index were evaluated. Histopathological lesions of the myocardium were graded. The influence of T. cruzi strain on the intensity of cardiac lesions was evaluated by the Chi-square test; the incidence of inflammatory lesions and its relationship to the parasite strain was evaluated by the Fisher test. The influence of the duration of infection was evaluated by using the Gamma Coefficient of Kruskal and Goodman and its measure of significance. Slight to severe microscopic alterations occurred in 85% of the chronically infected nice. There were a clear predominance on the incidence and intensity of inflammatory and fibrotic alterations for the mice infected with Type III strains. Statistical analysis has shown significant differences among the infected groups, in the inflammatory and fibrotic lesions. Macroscopic alterations (right cavities dilatation and apex

  1. Response pattern's of immunoglobulins evaluation in different lineages of mice infected with T. cruzi

    International Nuclear Information System (INIS)

    Silva, Andreia dos Santos

    2006-01-01

    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)

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

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    Samanta Cristina das Chagas Xavier

    2014-05-01

    Full Text Available BACKGROUND: The new epidemiological scenario of orally transmitted Chagas disease that has emerged in Brazil, and mainly in the Amazon region, needs to be addressed with a new and systematic focus. Belém, the capital of Pará state, reports the highest number of acute Chagas disease (ACD cases associated with the consumption of açaí juice. METHODOLOGY/PRINCIPAL FINDINGS: The wild and domestic enzootic transmission cycles of Trypanosoma cruzi were evaluated in the two locations (Jurunas and Val-de Cães that report the majority of the autochthonous cases of ACD in Belém city. Moreover, we evaluated the enzootic cycle on the three islands that provide most of the açaí fruit that is consumed in these localities. We employed parasitological and serological tests throughout to evaluate infectivity competence and exposure to T. cruzi. In Val-de-Cães, no wild mammal presented positive parasitological tests, and 56% seroprevalence was observed, with low serological titers. Three of 14 triatomines were found to be infected (TcI. This unexpected epidemiological picture does not explain the high number of autochthonous ACD cases. In Jurunas, the cases of ACD could not be autochthonous because of the absence of any enzootic cycle of T. cruzi. In contrast, in the 3 island areas from which the açaí fruit originates, 66.7% of wild mammals and two dogs displayed positive hemocultures, and 15.6% of triatomines were found to be infected by T. cruzi. Genotyping by mini-exon gene and PCR-RFLP (1f8/Akw21I targeting revealed that the mammals and triatomines from the islands harbored TcI and Trypanosoma rangeli in single and mixed infections. CONCLUSION/SIGNIFICANCE: These findings show that cases of Chagas disease in the urban area of Belém may be derived from infected triatomines coming together with the açaí fruits from distant islands. We term this new epidemiological feature of Chagas disease as "Distantiae transmission".

  3. Studies on the virulence and attenuation of Trypanosoma cruzi using immunodeficient animals

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    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.

  4. Presence of Trypanosoma cruzi in tissues of experimentally infected Wistar rats and their fetuses

    OpenAIRE

    Alarcón, Maritza; Lugo de Yarbuh, Ana; Moreno, Elio A; Payares, Gilberto; Araujo, Sonia; Colmenares, Melisa

    2006-01-01

    Este estudio fue realizado con un grupo de ratas juveniles hembras (Rattus norvegicus) cepa Wistar con 20 días de nacidas y 250 grs. de peso. Cada rata fue inoculada inyectándole por vía intraperitoneal 0.1 mL de la suspensión sanguínea con 1x105 tripomastigotes sanguícolas de Trypanosoma cruzi (cepa I/PAS/VE/00/PLANALTO). Los parásitos fueron aislados de Panstrongylus geniculatus, naturalmente infectado y capturado en un área urbana del valle de Caracas, Venezuela y mantenidos en ratones NMR...

  5. Avances en el estudio de la Adenilato Quinasa Nuclear de Trypanosoma cruzi

    OpenAIRE

    Cámara, María de los Milagros

    2012-01-01

    Trypanosoma cruzi, el agente etiológico del Mal de Chagas es un eucariota inferior en donde el control de la expresión génica recae mayormente en mecanismos postraduccionales. Durante todo su ciclo de vida se observan fluctuaciones en la expresión génica. En la presente tesis se realizó el estudio de una adenilato quinasa nuclear (TcADKn) que se encuentra involucrada en la biogénesis ribosomal. Las adenilato quinasas nucleares han sido descriptas en muy pocos organismos, se las ha asociado al...

  6. Immunity to alpha-Gal: Toward a Single-Antigen Pan-Vaccine To Control Major Infectious Diseases

    Czech Academy of Sciences Publication Activity Database

    Cabezas Cruz, Alejandro; de la Fuente, J.

    2017-01-01

    Roč. 3, č. 11 (2017), s. 1140-1142 ISSN 2374-7943 Institutional support: RVO:60077344 Keywords : Trypanosoma cruzi * trypomastigotes * carbohydrate Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 7.481, year: 2016

  7. Implementing a multifaceted intervention to decrease central line-associated bloodstream infections in SEHA (Abu Dhabi Health Services Company) intensive care units: the Abu Dhabi experience.

    Science.gov (United States)

    Latif, Asad; Kelly, Bernadette; Edrees, Hanan; Kent, Paula S; Weaver, Sallie J; Jovanovic, Branislava; Attallah, Hadeel; de Grouchy, Kristin K; Al-Obaidli, Ali; Goeschel, Christine A; Berenholtz, Sean M

    2015-07-01

    OBJECTIVE To determine whether implementation of a multifaceted intervention would significantly reduce the incidence of central line-associated bloodstream infections. DESIGN Prospective cohort collaborative. SETTING AND PARTICIPANTS Intensive care units of the Abu Dhabi Health Services Company hospitals in the Emirate of Abu Dhabi. INTERVENTIONS A bundled intervention consisting of 3 components was implemented as part of the program. It consisted of a multifaceted approach that targeted clinician use of evidence-based infection prevention recommendations, tools that supported the identification of local barriers to these practices, and implementation ideas to help ensure patients received the practices. Comprehensive unit-based safety teams were created to improve safety culture and teamwork. Finally, the measurement and feedback of monthly infection rate data to safety teams, senior leaders, and staff in participating intensive care units was encouraged. The main outcome measure was the quarterly rate of central line-associated bloodstream infections. RESULTS Eighteen intensive care units from 7 hospitals in Abu Dhabi implemented the program and achieved an overall 38% reduction in their central line-associated bloodstream infection rate, adjusted at the hospital and unit level. The number of units with a quarterly central line-associated bloodstream infection rate of less than 1 infection per 1,000 catheter-days increased by almost 40% between the baseline and postintervention periods. CONCLUSION A significant reduction in the global morbidity and mortality associated with central line-associated bloodstream infections is possible across intensive care units in disparate settings using a multifaceted intervention.

  8. Incidence of bloodstream infections in small bowel transplant recipients receiving selective decontamination of the digestive tract: A single-center experience.

    Science.gov (United States)

    Galloway, David; Danziger-Isakov, Lara; Goldschmidt, Monique; Hemmelgarn, Trina; Courter, Joshua; Nathan, Jaimie D; Alonso, Maria; Tiao, Greg; Fei, Lin; Kocoshis, Samuel

    2015-11-01

    Pediatric patients undergoing small bowel transplantation are susceptible to postoperative CLABSI. SDD directed against enteric microbes is a strategy for reducing CLABSI. We hypothesized that SDD reduces the frequency of CLABSI, infections outside the bloodstream, and allograft rejection during the first 30 days following transplant. A retrospective chart review of 38 pediatric small bowel transplant recipients at CCHMC from 2003 to 2011 was conducted. SDD antimicrobials were oral colistin, tobramycin, and amphotericin B. The incidence of CLABSI, infections outside the bloodstream, and rejection episodes were compared between study periods. The incidence of CLABSI did not differ between study periods (6.9 CLABSI vs. 4.6 CLABSI per 1000 catheter days; p = 0.727), but gram positives and Candida predominated in the first 30 days. Incidence of bacterial infections outside the bloodstream did not differ (p = 0.227). Rejection occurred more frequently during the first month following transplant (p = 0.302). SDD does not alter the incidence of CLABSI, bacterial infections outside the bloodstream, or allograft rejection in the immediate 30 days post-transplantation. However, SDD does influence CLABSI organism types (favoring gram positives and Candida) and Candidal infections outside the bloodstream. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. In vivo observation of the hypo-echoic "black hole" phenomenon in rat arterial bloodstream: a preliminary Study.

    Science.gov (United States)

    Nam, Kweon-Ho; Paeng, Dong-Guk

    2014-07-01

    The "black hole," a hypo-echoic hole at the center of the bloodstream surrounded by a hyper-echoic zone in cross-sectional views, has been observed in ultrasound backscattering measurements of blood with red blood cell aggregation in in vitro studies. We investigated whether the phenomenon occurs in the in vivo arterial bloodstream of rats using a high-frequency ultrasound imaging system. Longitudinal and cross-sectional ultrasound images of the rat common carotid artery (CCA) and abdominal aorta were obtained using a 40-MHz ultrasound system. A high-frame-rate retrospective imaging mode was employed to precisely examine the dynamic changes in blood echogenicity in the arteries. When the imaging was performed with non-invasive scanning, blood echogenicity was very low in the CCA as compared with the surrounding tissues, exhibiting no hypo-echoic zone at the center of the vessel. Invasive imaging of the CCA by incising the skin and subcutaneous tissues at the imaging area provided clearer and brighter blood echo images, showing the "black hole" phenomenon near the center of the vessel in longitudinal view. The "black hole" was also observed in the abdominal aorta under direct imaging after laparotomy. The aortic "black hole" was clearly observed in both longitudinal and cross-sectional views. Although the "black hole" was always observed near the center of the arteries during the diastolic phase, it dissipated or was off-center along with the asymmetric arterial wall dilation at systole. In conclusion, we report the first in vivo observation of the hypo-echoic "black hole" caused by the radial variation of red blood cell aggregation in arterial bloodstream. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  10. Emergence in Taiwan of novel imipenem-resistant Acinetobacter baumannii ST455 causing bloodstream infection in critical patients.

    Science.gov (United States)

    Lee, Hao-Yuan; Huang, Chih-Wei; Chen, Chyi-Liang; Wang, Yi-Hsin; Chang, Chee-Jen; Chiu, Cheng-Hsun

    2015-12-01

    Acinetobacter baumannii is one of the most important nosocomial pathogens worldwide. This study aimed to use multilocus sequence typing (MLST) for the epidemiological surveillance of A. baumannii isolates in Taiwan and analyze the clinical presentations and patients' outcome. MLST according to both Bartual's PubMLST and Pasteur's MLST schemes was applied to characterize bloodstream imipenem-resistant A. baumannii (IRAB) infection in intensive care units in a medical center. A total of 39 clinical IRAB bloodstream isolates in 2010 were enrolled. We also collected 13 imipenem-susceptible A. baumannii (ISAB) bloodstream isolates and 30 clinical sputum isolates (24 IRAB and 6 ISAB) for comparison. Clinical presentations and outcome of the patients were analyzed. We found that infection by ST455(B)/ST2(P) and inappropriate initial therapy were statistically significant risk factors for mortality. More than one-third of the IRAB isolates belonged to ST455(B)/ST2(P). Most ST455(B)/ST2(P) (80%) carried ISAba1-blaOXA-23, including 10 (66.7%) with Tn2006 (ISAba1-blaOXA-23-ISAba1) in an AbaR4-type resistance island. ST455(B)/ST2(P) appears to evolve from ST208(B)/ST2(P) of clonal complex (CC) 92(B)/CC2(P). In this hospital-based study, A. baumannii ST455 accounted for 38.5% of IRAB bacteremia, with a high mortality of 86.7%. Approximately 85% of ST455(B)/ST2(P)bacteremia had a primary source of ventilation-associated pneumonia. We report the emergence in Taiwan of IRAB ST455(B)/ST2(P), which is the current predominant clone of IRAB in our hospital and has been causing bacteremia with high mortality in critical patients. Copyright © 2015. Published by Elsevier B.V.

  11. Central line-associated bloodstream infections and catheter dwell-time: A theoretical foundation for a rule of thumb.

    Science.gov (United States)

    Voets, Philip J G M

    2018-05-14

    Many clinicians know from experience and medical epidemiological literature that the risk of central line-associated bloodstream infections (CLABSI) increases rapidly with a prolonged catheter dwell-time, but how this infection risk increases over time remains obscure. In this manuscript, a clinically useful rule of thumb is derived, stating that the risk of CLABSI increases in a quadratic fashion with the increase in catheter dwell-time. The proposed rule of thumb could be considered a quick and effortless clinical tool to rationally predict the pattern of CLABSI risk with an increasing catheter dwell-time. Copyright © 2018. Published by Elsevier Ltd.

  12. Effect of treatment with cyclophosphamide in low doses upon the onset of delayed type hypersensitivity in mice chronically infected with Trypanosoma cruzi: involvement of heart interstitial dendritic cells

    Directory of Open Access Journals (Sweden)

    Torriceli Souza The

    2013-09-01

    Full Text Available Acute infection with Trypanosoma cruzi results in intense myocarditis, which progresses to a chronic, asymptomatic indeterminate form. The evolution toward this chronic cardiac form occurs in approximately 30% of all cases of T. cruzi infection. Suppression of delayed type hypersensitivity (DTH has been proposed as a potential explanation of the indeterminate form. We investigated the effect of cyclophosphamide (CYCL treatment on the regulatory mechanism of DTH and the participation of heart interstitial dendritic cells (IDCs in this process using BALB/c mice chronically infected with T. cruzi. One group was treated with CYCL (20 mg/kg body weight for one month. A DTH skin test was performed by intradermal injection of T. cruzi antigen (3 mg/mL in the hind-footpad and measured the skin thickness after 24 h, 48 h and 72 h. The skin test revealed increased thickness in antigen-injected footpads, which was more evident in the mice treated with CYCL than in those mice that did not receive treatment. The thickened regions were characterised by perivascular infiltrates and areas of necrosis. Intense lesions of the myocardium were present in three/16 cases and included large areas of necrosis. Morphometric evaluation of lymphocytes showed a predominance of TCD8 cells. Heart IDCs were immunolabelled with specific antibodies (CD11b and CD11c and T. cruzi antigens were detected using a specific anti-T. cruzi antibody. Identification of T. cruzi antigens, sequestered in these cells using specific anti-T. cruzi antibodies was done, showing a significant increase in the number of these cells in treated mice. These results indicate that IDCs participate in the regulatory mechanisms of DTH response to T. cruzi infection.

  13. 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

  14. Role of blood culture systems in the evaluation of epidemiological features of coagulase-negative staphylococcal bloodstream infection in critically ill patients.

    Science.gov (United States)

    Oud, L; Krimerman, S; Salam, N; Srugo, I

    1999-12-01

    The impact of blood culture systems on the detection of coagulase-negative staphylococcal bloodstream infections in critically ill patients prior to and following the introduction of the Bactec 9240 blood culture system (Becton Dickinson Diagnostic Instrument Systems, USA), which replaced the Bactec NR 730 (Becton Dickinson Diagnostic Instrument Systems), was investigated over a 3-year period. Following the introduction of the new culture system, the incidence of bloodstream infections doubled (P<0.001). Patient demographics, severity of illness, and mortality remained unchanged, while the annual standardized mortality ratio decreased significantly. These data suggest that blood culture systems may have a major impact on the perceived incidence of coagulase-negative staphylococcal bloodstream infections in this population.

  15. Comparison of the systemic inflammatory response syndrome between monomicrobial and polymicrobial Pseudomonas aeruginosa nosocomial bloodstream infections

    Directory of Open Access Journals (Sweden)

    Wenzel Richard P

    2005-10-01

    Full Text Available Abstract Background Some studies of nosocomial bloodstream infection (nBSI have demonstrated a higher mortality for polymicrobial bacteremia when compared to monomicrobial nBSI. The purpose of this study was to compare differences in systemic inflammatory response and mortality between monomicrobial and polymicrobial nBSI with Pseudomonas aeruginosa. Methods We performed a historical cohort study on 98 adults with P. aeruginosa (Pa nBSI. SIRS scores were determined 2 days prior to the first positive blood culture through 14 days afterwards. Monomicrobial (n = 77 and polymicrobial BSIs (n = 21 were compared. Results 78.6% of BSIs were caused by monomicrobial P. aeruginosa infection (MPa and 21.4% by polymicrobial P. aeruginosa infection (PPa. Median APACHE II score on the day of BSI was 22 for MPa and 23 for PPa BSIs. Septic shock occurred in 33.3% of PPa and in 39.0% of MPa (p = 0.64. Progression to septic shock was associated with death more frequently in PPa (OR 38.5, CI95 2.9–508.5 than MPa (OR 4.5, CI95 1.7–12.1. Maximal SIR (severe sepsis, septic shock or death was seen on day 0 for PPa BSI vs. day 1 for MPa. No significant difference was noted in the incidence of organ failure, 7-day or overall mortality between the two groups. Univariate analysis revealed that APACHE II score ≥20 at BSI onset, Charlson weighted comorbidity index ≥3, burn injury and respiratory, cardiovascular, renal and hematologic failure were associated with death, while age, malignant disease, diabetes mellitus, hepatic failure, gastrointestinal complications, inappropriate antimicrobial therapy, infection with imipenem resistant P. aeruginosa and polymicrobial nBSI were not. Multivariate analysis revealed that hematologic failure (p Conclusion In this historical cohort study of nBSI with P. aeruginosa, the incidence of septic shock and organ failure was high in both groups. Additionally, patients with PPa BSI were not more acutely ill, as judged by APACHE II

  16. Molecular Identification and Echinocandin Susceptibility of Candida parapsilosis Complex Bloodstream Isolates in Italy, 2007-2014.

    Directory of Open Access Journals (Sweden)

    Grazia Lovero

    Full Text Available The Candida parapsilosis group encompasses three species: C. parapsilosis, C. orthopsilosis, and C. metapsilosis. Here, we describe the incidence and echinocandin susceptibility profile of bloodstream isolates of these three species collected from patients admitted to an Italian university hospital from 2007 to 2014. Molecular identification of cryptic species of the C. parapsilosis complex was performed using polymerase chain reaction amplification of the gene encoding secondary alcohol dehydrogenase, followed by digestion with the restriction enzyme BanI. Minimum inhibitory concentrations were determined using the broth microdilution method according to European Committee for Antimicrobial Susceptibility Testing (EUCAST EDef 7.2 and Clinical Laboratory Standards Institute (CLSI M27-A3 guidelines, and the results were compared with those obtained using the E-test and Sensititre methods. Of the 163 C. parapsilosis complex isolates, 136 (83.4% were identified as C. parapsilosis, and 27 (16.6% as C. orthopsilosis. The species-specific incidences were 2.9/10,000 admissions for C. parapsilosis and 0.6/10,000 admissions for C. orthopsilosis. No resistance to echinocandins was detected with any of the methods. The percent essential agreement (EA between the EUCAST and E-test/Sensititre methods for anidulafungin, caspofungin, and micafungin susceptibility was, respectively, as follows: C. parapsilosis, 95.6/97.8, 98.5/88.2, and 93.4/96.3; C. orthopsilosis, 92.6/92.6, 96.3/77.8, and 63.0/66.7. The EA between the CLSI and E-test/Sensititre methods was, respectively, as follows: C. parapsilosis, 99.3/100, 98.5/89.0, and 96.3/98.5; C. orthopsilosis, 96.3/92.6, 100/81.5, and 92.6/88.9. Only minor discrepancies, ranging from 16.9% (C. parapsilosis to 11.1% (C. orthopsilosis, were observed between the CLSI and E-test/Sensititre methods. In conclusion, this epidemiologic study shows a typical C. parapsilosis complex species distribution, no echinocandin

  17. Positive deviance as a strategy to prevent and control bloodstream infections in intensive care.

    Science.gov (United States)

    Oliveira, Francimar Tinoco de; Ferreira, Maria Manuela Frederico; Araújo, Silvia Teresa Carvalho de; Bessa, Amanda Trindade Teixeira de; Moraes, Advi Catarina Barbachan; Stipp, Marluci Andrade Conceição

    2017-04-03

    To describe the application of positive deviance as a strategy to prevent and control bloodstream infections. An intervention study with nursing and medical team members working in an intensive care unit in a university hospital, between June and December 2014. The four steps of the positive defiance methodology were applied: to define, to determine, to discover and to design. In 90 days, 188 actions were observed, of these, 36.70% (n=69) were related to catheter dressing. In 81.15% (n=56) of these dressings, the professionals most adhered to the use of flexible sterile cotton-tipped swabs to perform antisepsis at catheter entry sites and fixation dressing. Positive deviance contributed to the implementation of proposals to improve work processes and team development related to problems identified in central venous catheter care. Descrever a aplicação do Positive Deviance como estratégia na prevenção e no controle da infecção de corrente sanguínea. Estudo de intervenção realizado na Unidade de Terapia Intensiva de um hospital universitário, com os membros das equipes de enfermagem e médica, de junho a dezembro de 2014. Foram aplicados os quatro passos da metodologia Positive Deviance: Definir, Determinar, Descobrir e Desenhar. Em 90 dias 188 ações foram observadas, destas, 36,70% (n=69) estavam relacionadas aos curativos dos cateteres. Em 81,15% (n=56) desses curativos, o uso da haste flexível estéril para realização da antissepsia do local de inserção do cateter e de sua placa de fixação foi a ação de maior adesão. O Positive Deviance auxiliou na implementação de propostas de melhorias de processo de trabalho e no desenvolvimento da equipe para os problemas identificados no cuidado com o cateter venoso central.

  18. Structural model of a putrescine-cadaverine permease from Trypanosoma cruzi predicts residues vital for transport and ligand binding

    NARCIS (Netherlands)

    Soysa, R.; Venselaar, H.; Poston, J.; Ullman, B.; Hasne, M.P.

    2013-01-01

    The TcPOT1.1 gene from Trypanosoma cruzi encodes a high affinity putrescine-cadaverine transporter belonging to the APC (amino acid/polyamine/organocation) transporter superfamily. No experimental three-dimensional structure exists for any eukaryotic member of the APC family, and thus the structural

  19. 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

  20. [A confirmatory diagnosis of antibodies anti-Trypanosoma cruzi in donors referred by blood banks in Venezuela].

    Science.gov (United States)

    Díaz-Bello, Zoraida; Zavala-Jaspe, Reinaldo; Díaz-Villalobos, María; Mauriello, Luciano; Maekelt, Alberto; de Noya, Belkisyolé Alarcón

    2008-06-01

    To establish the confirmatory diagnosis of Trypanosoma cruzi infection, at least two immunoserological tests (ELISA, Indirect hamaglutination, IH, Complement Fixation Test, CFT) were carried out in 254 donors, from public and private blood banks of Venezuela, during