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Sample records for bloodstream form trypanosoma

  1. 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

  2. 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

  3. 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

  4. 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

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

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    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.

  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. 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.

  8. Cell-cycle synchronisation of bloodstream forms of Trypanosoma brucei using Vybrant DyeCycle Violet-based sorting.

    Science.gov (United States)

    Kabani, Sarah; Waterfall, Martin; Matthews, Keith R

    2010-01-01

    Studies on the cell-cycle of Trypanosoma brucei have revealed several unusual characteristics that differ from the model eukaryotic organisms. However, the inability to isolate homogenous populations of parasites in distinct cell-cycle stages has limited the analysis of trypanosome cell division and complicated the understanding of mutant phenotypes with possible impact on cell-cycle related events. Although hydroxyurea-induced cell-cycle arrest in procyclic and bloodstream forms has been applied recently with success, such block-release protocols can complicate the analysis of cell-cycle regulated events and have the potential to disrupt important cell-cycle checkpoints. An alternative approach based on flow cytometry of parasites stained with Vybrant DyeCycle Orange circumvents this problem, but is restricted to procyclic form parasites. Here, we apply Vybrant Dyecycle Violet staining coupled with flow cytometry to effectively select different cell-cycle stages of bloodstream form trypanosomes. Moreover, the sorted parasites remain viable, although synchrony is rapidly lost. This method enables cell-cycle enrichment of populations of trypanosomes in their mammal infective stage, particularly at the G1 phase.

  9. 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.

  10. 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.

  11. Trypanocidal action of bisphosphonium salts through a mitochondrial target in bloodstream form Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Alkhaldi, A.A.M.; Martínek, Jan; Panicucci, Brian; Dardonville, C.; Zíková, Alena; de Koning, H.P.

    2016-01-01

    Roč. 6, č. 1 (2016), s. 23-34 ISSN 2211-3207 R&D Projects: GA MŠk LL1205 Institutional support: RVO:60077344 Keywords : Trypanosoma brucei * mitochondrion * FoF1 ATPase * succinate dehydrogenase * phosphonium salt * SDH complex Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.809, year: 2016

  12. Trypanosoma brucei gambiense: HMI-9 medium containing methylcellulose and human serum supports the continuous axenic in vitro propagation of the bloodstream form.

    Science.gov (United States)

    Van Reet, N; Pyana, P P; Deborggraeve, S; Büscher, P; Claes, F

    2011-07-01

    Trypanosoma brucei (T.b.) gambiense causes the chronic form of human African trypanosomiasis or sleeping sickness. One of the major problems with studying T.b. gambiense is the difficulty to isolate it from its original host and the difficult adaptation to in vivo and in vitro mass propagation. The objective of this study was to evaluate if an established method for axenic culture of pleomorphic bloodstream form T.b. brucei strains, based on methylcellulose containing HMI-9 medium, also facilitated the continuous in vitro propagation of other bloodstream form Trypanozoon strains, in particular of T.b. gambiense. Bloodstream form trypanosomes from one T.b. brucei, two T.b. rhodesiense, one T. evansi and seven T.b. gambiense strains were isolated from mouse blood and each was concurrently cultivated in liquid and methylcellulose-containing HMI-9 based medium, either with or without additional human serum supplementation, for over 10 consecutive sub passages. Although HMI-9 based medium supplemented with 1.1% (w/v) methylcellulose supported the continuous cultivation of all non-gambiense strains better than liquid media could, the in vitro cultivation of all gambiense strains was only achieved in HMI-9 based medium containing 1.1% (w/v) methylcellulose, 15% (v/v) fetal calf serum and 5% (v/v) heat-inactivated human serum. Copyright © 2011 Elsevier Inc. All rights reserved.

  13. 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.

  14. 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 ...

  15. 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

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

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    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.

  17. 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.

  18. In or out? On the tightness of glycosomal compartmentalization of metabolites and enzymes in Trypanosoma brucei

    NARCIS (Netherlands)

    Haanstra, Jurgen R.; Bakker, Barbara M.; Michels, Paul A. M.

    Trypanosomatids sequester large parts of glucose metabolism inside specialised peroxisomes, called glycosomes. Many studies have shown that correct glycosomal compartmentalization of glycolytic enzymes is essential for bloodstream-form Trypanosoma brucel. The recent finding of pore-forming

  19. Trypanosoma brucei mitochondrial respiratome: Composition and organization in procyclic form

    KAUST Repository

    Acestor, Nathalie

    2011-05-24

    The mitochondrial respiratory chain is comprised of four different protein complexes (I-IV), which are responsible for electron transport and generation of proton gradient in the mitochondrial intermembrane space. This proton gradient is then used by F oF 1-ATP synthase (complex V) to produce ATP by oxidative phosphorylation. In this study, the respiratory complexes I, II, and III were affinity purified from Trypanosoma brucei procyclic form cells and their composition was determined by mass spectrometry. The results along with those that we previously reported for complexes IV and V showed that the respiratome of Trypanosoma is divergent because many of its proteins are unique to this group of organisms. The studies also identified two mitochondrial subunit proteins of respiratory complex IV that are encoded by edited RNAs. Proteomics data from analyses of complexes purified using numerous tagged component proteins in each of the five complexes were used to generate the first predicted protein-protein interaction network of the Trypanosoma brucei respiratory chain. These results provide the first comprehensive insight into the unique composition of the respiratory complexes in Trypanosoma brucei, an early diverged eukaryotic pathogen. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.

  20. A paradigm shift: The mitoproteomes of procyclic and bloodstream Trypanosoma brucei are comparably complex

    Czech Academy of Sciences Publication Activity Database

    Zíková, Alena; Verner, Zdeněk; Nenarokova, Anna; Michele, P. A. M.; Lukeš, Julius

    2017-01-01

    Roč. 13, č. 12 (2017), č. článku e1006679. ISSN 1553-7366 R&D Projects: GA MŠk LL1205; GA MŠk LL1601; GA ČR GA17-22248S; GA ČR GA15-21974S; GA MŠk(CZ) LQ1604 Institutional support: RVO:60077344 Keywords : life-cycle stages * african trypanosomes * adp/atp carrier * krebs cycle * forms * mitochondrion * reveals * protein * metabolism * glucose Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 6.608, year: 2016

  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. Proteome remodelling during development from blood to insect-form Trypanosoma brucei quantified by SILAC and mass spectrometry

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    Gunasekera Kapila

    2012-10-01

    Full Text Available Abstract Background Trypanosoma brucei is the causative agent of human African sleeping sickness and Nagana in cattle. In addition to being an important pathogen T. brucei has developed into a model system in cell biology. Results Using Stable Isotope Labelling of Amino acids in Cell culture (SILAC in combination with mass spectrometry we determined the abundance of >1600 proteins in the long slender (LS, short stumpy (SS mammalian bloodstream form stages relative to the procyclic (PC insect-form stage. In total we identified 2645 proteins, corresponding to ~30% of the total proteome and for the first time present a comprehensive overview of relative protein levels in three life stages of the parasite. Conclusions We can show the extent of pre-adaptation in the SS cells, especially at the level of the mitochondrial proteome. The comparison to a previously published report on monomorphic in vitro grown bloodstream and procyclic T. brucei indicates a loss of stringent regulation particularly of mitochondrial proteins in these cells when compared to the pleomorphic in vivo situation. In order to better understand the different levels of gene expression regulation in this organism we compared mRNA steady state abundance with the relative protein abundance-changes and detected moderate but significant correlation indicating that trypanosomes possess a significant repertoire of translational and posttranslational mechanisms to regulate protein abundance.

  3. Major surface glycoproteins of insect forms of Trypanosoma brucei are not essential for cyclical transmission by tsetse.

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    Erik Vassella

    Full Text Available Procyclic forms of Trypanosoma brucei reside in the midgut of tsetse flies where they are covered by several million copies of glycosylphosphatidylinositol-anchored proteins known as procyclins. It has been proposed that procyclins protect parasites against proteases and/or participate in tropism, directing them from the midgut to the salivary glands. There are four different procyclin genes, each subject to elaborate levels of regulation. To determine if procyclins are essential for survival and transmission of T. brucei, all four genes were deleted and parasite fitness was compared in vitro and in vivo. When co-cultured in vitro, the null mutant and wild type trypanosomes (tagged with cyan fluorescent protein maintained a near-constant equilibrium. In contrast, when flies were infected with the same mixture, the null mutant was rapidly overgrown in the midgut, reflecting a reduction in fitness in vivo. Although the null mutant is patently defective in competition with procyclin-positive parasites, on its own it can complete the life cycle and generate infectious metacyclic forms. The procyclic form of T. brucei thus differs strikingly from the bloodstream form, which does not tolerate any perturbation of its variant surface glycoprotein coat, and from other parasites such as Plasmodium berghei, which requires the circumsporozoite protein for successful transmission to a new host.

  4. Trypanosoma brucei Mitochondrial Respiratome: Composition and Organization in Procyclic Form

    Czech Academy of Sciences Publication Activity Database

    Acestor, N.; Zíková, Alena; Dalley, R. A.; Anupama, A.; Panigrahi, A. K.; Stuart, K. D.

    2011-01-01

    Roč. 10, č. 9 (2011), s. 1-14 ISSN 1535-9476 R&D Projects: GA ČR GP204/09/P563 Institutional research plan: CEZ:AV0Z60220518 Keywords : SUCCINATE DEHYDROGENASE * EDITED MESSENGER-RNA * COMPLEX-I * TRYPANOSOMA-BRUCEI * UBIQUINONE OXIDOREDUCTASE * TAP-TAG * PROTEIN INTERACTION * ALTERNATIVE OXIDASE * STATISTICAL-MODEL * MASS-SPECTROMETRY Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.398, year: 2011

  5. 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).

    Science.gov (United States)

    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.

  6. Trypanosoma brucei TbIF1 inhibits the essential F1-ATPase in the infectious form of the parasite.

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    Brian Panicucci

    2017-04-01

    Full Text Available The mitochondrial (mt FoF1-ATP synthase of the digenetic parasite, Trypanosoma brucei, generates ATP during the insect procyclic form (PF, but becomes a perpetual consumer of ATP in the mammalian bloodstream form (BF, which lacks a canonical respiratory chain. This unconventional dependence on FoF1-ATPase is required to maintain the essential mt membrane potential (Δψm. Normally, ATP hydrolysis by this rotary molecular motor is restricted to when eukaryotic cells experience sporadic hypoxic conditions, during which this compulsory function quickly depletes the cellular ATP pool. To protect against this cellular treason, the highly conserved inhibitory factor 1 (IF1 binds the enzyme in a manner that solely inhibits the hydrolytic activity. Intriguingly, we were able to identify the IF1 homolog in T. brucei (TbIF1, but determined that its expression in the mitochondrion is tightly regulated throughout the life cycle as it is only detected in PF cells. TbIF1 appears to primarily function as an emergency brake in PF cells, where it prevented the restoration of the Δψm by FoF1-ATPase when respiration was chemically inhibited. In vitro, TbIF1 overexpression specifically inhibits the hydrolytic activity but not the synthetic capability of the FoF1-ATP synthase in PF mitochondria. Furthermore, low μM amounts of recombinant TbIF1 achieve the same inhibition of total mt ATPase activity as the FoF1-ATPase specific inhibitors, azide and oligomycin. Therefore, even minimal ectopic expression of TbIF1 in BF cells proved lethal as the indispensable Δψm collapsed due to inhibited FoF1-ATPase. In summary, we provide evidence that T. brucei harbors a natural and potent unidirectional inhibitor of the vital FoF1-ATPase activity that can be exploited for future structure-based drug design.

  7. Trypanocidal activity of Brazilian plants against epimastigote forms from Y and Bolivia strains of Trypanosoma cruzi

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    Renata Tomé Alves

    2012-01-01

    Full Text Available Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 µg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93 and Aegiphila lhotzkiana (Am160. Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.

  8. Quantitative Proteomic and Phosphoproteomic Analysis of Trypanosoma cruzi Amastigogenesis

    DEFF Research Database (Denmark)

    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...

  9. Essential Assembly Factor Rpf2 Forms Novel Interactions within the 5S RNP in Trypanosoma brucei.

    Science.gov (United States)

    Kamina, Anyango D; Jaremko, Daniel; Christen, Linda; Williams, Noreen

    2017-01-01

    Ribosome biogenesis is a highly complex and conserved cellular process that is responsible for making ribosomes. During this process, there are several assembly steps that function as regulators to ensure proper ribosome formation. One of these steps is the assembly of the 5S ribonucleoprotein particle (5S RNP) in the central protuberance of the 60S ribosomal subunit. In eukaryotes, the 5S RNP is composed of 5S rRNA, ribosomal proteins L5 and L11, and assembly factors Rpf2 and Rrs1. Our laboratory previously showed that in Trypanosoma brucei , the 5S RNP is composed of 5S rRNA, L5, and trypanosome-specific RNA binding proteins P34 and P37. In this study, we characterize an additional component of the 5S RNP, the T. brucei homolog of Rpf2. This is the first study to functionally characterize interactions mediated by Rpf2 in an organism other than fungi. T . brucei Rpf2 (TbRpf2) was identified from tandem affinity purification using extracts prepared from protein A-tobacco etch virus (TEV)-protein C (PTP)-tagged L5, P34, and P37 cell lines, followed by mass spectrometry analysis. We characterized the binding interactions between TbRpf2 and the previously characterized members of the T. brucei 5S RNP. Our studies show that TbRpf2 mediates conserved binding interactions with 5S rRNA and L5 and that TbRpf2 also interacts with trypanosome-specific proteins P34 and P37. We performed RNA interference (RNAi) knockdown of TbRpf2 and showed that this protein is essential for the survival of the parasites and is critical for proper ribosome formation. These studies provide new insights into a critical checkpoint in the ribosome biogenesis pathway in T. brucei . IMPORTANCE Trypanosoma brucei is the parasitic protozoan that causes African sleeping sickness. Ribosome assembly is essential for the survival of this parasite through the different host environments it encounters during its life cycle. The assembly of the 5S ribonucleoprotein particle (5S RNP) functions as one of

  10. 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

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

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    Lúcia Maria C. Galvão

    1981-09-01

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

  12. Studies on the glycosome of Trypanosoma brucei

    International Nuclear Information System (INIS)

    Aman, R.A.

    1985-01-01

    Glycosomes (microbodies) have been purified from bloodstream form Trypanosoma brucei by an improved procedure involving freezing and thawing live organisms in 15% glycerol prior to cell disruption. Highly purified organelles of bloodstream form T. brucei contain 11 major proteins of which 8 tentatively identified glycolytic enzymes make up about 90% of the total glycosomal protein. Treatment of these intact isolated organelles with the bisimidoester dimethylsuberimidate (DMSI) resulted in crosslinking of all glycosomal proteins into a large complex suggestive of juxtapositioning of the glycosomal proteins. The crosslinked complex was capable of catalyzing the multienzyme conversion of glucose to glycerol-3-phosphate but did not possess any special kinetic features different from those of the unaggregated enzymes represented by solubilized glycosomes. The multienzyme reaction had a lab phase associated with it and [ 14 C]-glucose label incorporation into sugar phosphate intermediates was effectively competed by unlabeled intermediates. Glycosomes were also purified from culture form T. brucei by several different procedures. Comparison of highly purified organelles from the two different life stages of the organism showed reduced specific activities and contents of the early glycolytic enzymes in organelles from the culture form with a decrease from 87% to 35% of the contribution of glycolytic enzymes to the total glycosomal protein

  13. Improved Method for In Vitro Secondary Amastigogenesis of Trypanosoma cruzi: Morphometrical and Molecular Analysis of Intermediate Developmental Forms

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    L. A. Hernández-Osorio

    2010-01-01

    Full Text Available Trypanosoma cruzi undergoes a biphasic life cycle that consists of four alternate developmental stages. In vitro conditions to obtain a synchronic transformation and efficient rates of pure intermediate forms (IFs, which are indispensable for further biochemical, biological, and molecular studies, have not been reported. In the present study, we established an improved method to obtain IFs from secondary amastigogenesis. During the transformation kinetics, we observed progressive decreases in the size of the parasite body, undulating membrane and flagellum that were concomitant with nucleus remodeling and kinetoplast displacement. In addition, a gradual reduction in parasite movement and acquisition of the amastigote-specific Ssp4 antigen were observed. Therefore, our results showed that the in vitro conditions used obtained large quantities of highly synchronous and pure IFs that were clearly distinguished by morphometrical and molecular analyses. Obtaining these IFs represents the first step towards an understanding of the molecular mechanisms involved in amastigogenesis.

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

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    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.

  15. Trypanosoma cruzi prevalence and clinical forms in blood donor candidates in Brazil Prevalência e formas clínicas de Trypanosoma cruzi em candidatos a doadores de sangue no Brasil

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    H J Silveira

    2003-12-01

    Full Text Available The prevalence and clinical forms of Trypanosoma cruzi were evaluated among blood donor candidates attended at a general hospital in Rio de Janeiro, Brazil, from January 1997 to April 1999. The investigation was done by means of the indirect hemagglutination test and was confirmed via ELISA. Data were collected from clinical examinations, conventional electrocardiogram, chest radiography and echocar-diography. The results showed that despite Trypanosoma cruzi prevalence of 1.17% (128 patients, mainly in males aged 40 years or over, 70.8% of these patients, mainly males aged 19 to 39 years, demonstrated abnormalities that allowed the diagnosis of cardiopathy and/or esophagopathy. This once again corroborates the importance of Trypanosoma cruzi infection in urban centers.A prevalência e a manifestação das formas clinicas de Trypanosoma cruzi foram avaliadas em candidatos a doadores de sangue atendidos em um hospital geral de Nova Iguaçu, Rio de Janeiro, Brasil, no período de janeiro de 1997 a abril de 1999. A pesquisa sorológica foi realizada por meio do teste de hemaglutinação indireta e confirmada pelo ELISA. Os dados foram coletados considerando os exames clínicos, eletrocardiograma convencional, radiografia de tórax e ecocardiografia. Os resultados demonstraram que, apesar da prevalência ser de 1,17% (128 pacientes, principalmente entre homens com idade igual ou superior a 40 anos, 70,8%, principalmente de homens entre 19 e 39 anos, demonstraram alterações que permitiram o diagnóstico de cardiopatias e/ou esofagopatias, ratificando mais uma vez sua importância nos centros urbanos.

  16. Endogenous sterol biosynthesis is important for mitochondrial function and cell morphology in procyclic forms of Trypanosoma brucei.

    Science.gov (United States)

    Pérez-Moreno, Guiomar; Sealey-Cardona, Marco; Rodrigues-Poveda, Carlos; Gelb, Michael H; Ruiz-Pérez, Luis Miguel; Castillo-Acosta, Víctor; Urbina, Julio A; González-Pacanowska, Dolores

    2012-10-01

    Sterol biosynthesis inhibitors are promising entities for the treatment of trypanosomal diseases. Insect forms of Trypanosoma brucei, the causative agent of sleeping sickness, synthesize ergosterol and other 24-alkylated sterols, yet also incorporate cholesterol from the medium. While sterol function has been investigated by pharmacological manipulation of sterol biosynthesis, molecular mechanisms by which endogenous sterols influence cellular processes remain largely unknown in trypanosomes. Here we analyse by RNA interference, the effects of a perturbation of three specific steps of endogenous sterol biosynthesis in order to dissect the role of specific intermediates in proliferation, mitochondrial function and cellular morphology in procyclic cells. A decrease in the levels of squalene synthase and squalene epoxidase resulted in a depletion of cellular sterol intermediates and end products, impaired cell growth and led to aberrant morphologies, DNA fragmentation and a profound modification of mitochondrial structure and function. In contrast, cells deficient in sterol methyl transferase, the enzyme involved in 24-alkylation, exhibited a normal growth phenotype in spite of a complete abolition of the synthesis and content of 24-alkyl sterols. Thus, the data provided indicates that while the depletion of squalene and post-squalene endogenous sterol metabolites results in profound cellular defects, bulk 24-alkyl sterols are not strictly required to support growth in insect forms of T. brucei in vitro. Copyright © 2012 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  17. Kinetoplast adaptations in American strains from Trypanosoma vivax

    Energy Technology Data Exchange (ETDEWEB)

    Greif, Gonzalo [Unidad de Biología Molecular, Institut Pasteur de Montevideo (Uruguay); Rodriguez, Matías [Sección Biomatemática, Facultad de Ciencias, Universidad de la Republica (Uruguay); Reyna-Bello, Armando [Departamento de Ciencias de la Vida, Carrera en Ingeniería en Biotecnología, Universidad de las Fuerzas Armadas (Ecuador); Centro de Estudios Biomédicos y Veterinarios, Universidad Nacional Experimental Simón Rodríguez-IDECYT, Caracas (Venezuela, Bolivarian Republic of); Robello, Carlos [Unidad de Biología Molecular, Institut Pasteur de Montevideo (Uruguay); Departamento de Bioquímica, Facultad de Medicina, Universidad de la República Uruguay (Uruguay); Alvarez-Valin, Fernando, E-mail: falvarez@fcien.edu.uy [Sección Biomatemática, Facultad de Ciencias, Universidad de la Republica (Uruguay)

    2015-03-15

    Highlights: • American T. vivax strains exhibit a drastic process of mitochondrial genome degradation. • T. vivax mitochondrial genes have among the fastest evolutionary rates in eukaryotes. • High rates of kDNA evolution are associated with relaxation of selective constrains. • Relaxed selective pressures are the result of mechanical transmission. • The evolutionary strategy of T. vivax differs from that of T. brucei-species complex. - Abstract: The mitochondrion role changes during the digenetic life cycle of African trypanosomes. Owing to the low abundance of glucose in the insect vector (tsetse flies) the parasites are dependent upon a fully functional mitochondrion, capable of performing oxidative phosphorylation. Nevertheless, inside the mammalian host (bloodstream forms), which is rich in nutrients, parasite proliferation relies on glycolysis, and the mitochondrion is partially redundant. In this work we perform a comparative study of the mitochondrial genome (kinetoplast) in different strains of Trypanosoma vivax. The comparison was conducted between a West African strain that goes through a complete life cycle and two American strains that are mechanically transmitted (by different vectors) and remain as bloodstream forms only. It was found that while the African strain has a complete and apparently fully functional kinetoplast, the American T. vivax strains have undergone a drastic process of mitochondrial genome degradation, in spite of the recent introduction of these parasites in America. Many of their genes exhibit different types of mutations that are disruptive of function such as major deletions, frameshift causing indels and missense mutations. Moreover, all but three genes (A6-ATPase, RPS12 and MURF2) are not edited in the American strains, whereas editing takes place normally in all (editable) genes from the African strain. Two of these genes, A6-ATPase and RPS12, are known to play an essential function during bloodstream stage

  18. Kinetoplast adaptations in American strains from Trypanosoma vivax

    International Nuclear Information System (INIS)

    Greif, Gonzalo; Rodriguez, Matías; Reyna-Bello, Armando; Robello, Carlos; Alvarez-Valin, Fernando

    2015-01-01

    Highlights: • American T. vivax strains exhibit a drastic process of mitochondrial genome degradation. • T. vivax mitochondrial genes have among the fastest evolutionary rates in eukaryotes. • High rates of kDNA evolution are associated with relaxation of selective constrains. • Relaxed selective pressures are the result of mechanical transmission. • The evolutionary strategy of T. vivax differs from that of T. brucei-species complex. - Abstract: The mitochondrion role changes during the digenetic life cycle of African trypanosomes. Owing to the low abundance of glucose in the insect vector (tsetse flies) the parasites are dependent upon a fully functional mitochondrion, capable of performing oxidative phosphorylation. Nevertheless, inside the mammalian host (bloodstream forms), which is rich in nutrients, parasite proliferation relies on glycolysis, and the mitochondrion is partially redundant. In this work we perform a comparative study of the mitochondrial genome (kinetoplast) in different strains of Trypanosoma vivax. The comparison was conducted between a West African strain that goes through a complete life cycle and two American strains that are mechanically transmitted (by different vectors) and remain as bloodstream forms only. It was found that while the African strain has a complete and apparently fully functional kinetoplast, the American T. vivax strains have undergone a drastic process of mitochondrial genome degradation, in spite of the recent introduction of these parasites in America. Many of their genes exhibit different types of mutations that are disruptive of function such as major deletions, frameshift causing indels and missense mutations. Moreover, all but three genes (A6-ATPase, RPS12 and MURF2) are not edited in the American strains, whereas editing takes place normally in all (editable) genes from the African strain. Two of these genes, A6-ATPase and RPS12, are known to play an essential function during bloodstream stage

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

    DEFF Research Database (Denmark)

    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...

  20. antigen from irradiated Trypanosoma evansi and its correlation with antibody forming

    International Nuclear Information System (INIS)

    Sadi, Suharni; Arifin, Muchson

    1998-01-01

    In this research parasites of T. evansi was weakened by gamma irradiation dose of 300 Gy. This antigen being before being used was coupled/bounded with a carrier (Freund's adjuvant). West star rats of 3 months old were as used as treated animal. These animal were divided into 4 groups contained 5 rats. Group I (Control) was untreated animals, Group II (radiation) the animals were irradiated with a low dose 0.5 Gy. Group III Immunization) the animals were immunized with irradiated antigen, and Group IV (Immunization and radiation) the animal were immunized and then irradiated with a low dose of 0.5 Gy. Immunization were done by intraperitoneal route with irradiated antigen (0.5-1ml). These results were as follows : the polyclonal antibody forming of Group I (control), Group II (Radiation), Group III (Immunization), and Group IV (Immunization and radiation) were 6.34; 5.96; and 5.88 mg/ml, respectively. Group III (Immunization) Yielded polyclonal antibody a little higher than the other treated animals. Even though the antigen was coupled with a carrier, it seemed that it did not influence the parasites variant antigenic types (VTA). (author)

  1. Increased levels of IgA antibodies against CRA and FRA recombinant antigens of Trypanosoma cruzi differentiate digestive forms of Chagas disease.

    Science.gov (United States)

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

    2010-10-01

    In the chronic phase of Chagas disease, individuals infected by Trypanosoma cruzi may be asymptomatic or may present cardiac and/or digestive complications. Our aim here was to analyze the relationship between the presence of specific immunoglobulin A antibodies and the different chronic clinical forms of Chagas disease using two recombinant antigens of Trypanosoma cruzi, cytoplasmatic repetitive antigen and flagellar repetitive antigen. The association of this immunoglobulin isotype with the digestive and cardio-digestive forms of the disease determined by indirect enzyme-linked immunosorbent assay, strongly suggests that IgA antibodies against these recombinant antigens of T. cruzi can be used as an immunological marker of the digestive alterations caused by Chagas disease. The tests performed in this study show that it is possible to differentiate digestive forms of Chagas disease. The knowledge provided by these results may help physicians to manage early alterations in the digestive tract of patients with the indeterminate or cardiac forms of Chagas disease. Prospective studies, however, with follow-up of the patients that presenting with high levels of immunoglobulin A against cytoplasmatic repetitive antigen and flagellar repetitive antigen recombinant antigens, need to be conducted to confirm this hypothesis. 2010 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. An Atypical Mitochondrial Carrier That Mediates Drug Action in Trypanosoma brucei.

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    Juan P de Macêdo

    2015-05-01

    Full Text Available Elucidating the mechanism of action of trypanocidal compounds is an important step in the development of more efficient drugs against Trypanosoma brucei. In a screening approach using an RNAi library in T. brucei bloodstream forms, we identified a member of the mitochondrial carrier family, TbMCP14, as a prime candidate mediating the action of a group of anti-parasitic choline analogs. Depletion of TbMCP14 by inducible RNAi in both bloodstream and procyclic forms increased resistance of parasites towards the compounds by 7-fold and 3-fold, respectively, compared to uninduced cells. In addition, down-regulation of TbMCP14 protected bloodstream form mitochondria from a drug-induced decrease in mitochondrial membrane potential. Conversely, over-expression of the carrier in procyclic forms increased parasite susceptibility more than 13-fold. Metabolomic analyses of parasites over-expressing TbMCP14 showed increased levels of the proline metabolite, pyrroline-5-carboxylate, suggesting a possible involvement of TbMCP14 in energy production. The generation of TbMCP14 knock-out parasites showed that the carrier is not essential for survival of T. brucei bloodstream forms, but reduced parasite proliferation under standard culture conditions. In contrast, depletion of TbMCP14 in procyclic forms resulted in growth arrest, followed by parasite death. The time point at which parasite proliferation stopped was dependent on the major energy source, i.e. glucose versus proline, in the culture medium. Together with our findings that proline-dependent ATP production in crude mitochondria from TbMCP14-depleted trypanosomes was reduced compared to control mitochondria, the study demonstrates that TbMCP14 is involved in energy production in T. brucei. Since TbMCP14 belongs to a trypanosomatid-specific clade of mitochondrial carrier family proteins showing very poor similarity to mitochondrial carriers of mammals, it may represent an interesting target for drug

  5. Troglitazone induces differentiation in Trypanosoma brucei

    International Nuclear Information System (INIS)

    Denninger, Viola; Figarella, Katherine; Schoenfeld, Caroline; Brems, Stefanie; Busold, Christian; Lang, Florian; Hoheisel, Joerg; Duszenko, Michael

    2007-01-01

    Trypanosoma brucei, a protozoan parasite causing sleeping sickness, is transmitted by the tsetse fly and undergoes a complex lifecycle including several defined stages within the insect vector and its mammalian host. In the latter, differentiation from the long slender to the short stumpy form is induced by a yet unknown factor of trypanosomal origin. Here we describe that some thiazolidinediones are also able to induce differentiation. In higher eukaryotes, thiazolidinediones are involved in metabolism and differentiation processes mainly by binding to the intracellular receptor peroxisome proliferator activated receptor γ. Our studies focus on the effects of troglitazone on bloodstream form trypanosomes. Differentiation was monitored using mitochondrial markers (membrane potential, succinate dehydrogenase activity, inhibition of oxygen uptake by KCN, amount of cytochrome transcripts), morphological changes (Transmission EM and light microscopy), and transformation experiments (loss of the Variant Surface Glycoprotein coat and increase of dihydroliponamide dehydrogenase activity). To further investigate the mechanisms responsible for these changes, microarray analyses were performed, showing an upregulation of expression site associated gene 8 (ESAG8), a potential differentiation regulator

  6. Cell signaling during Trypanosoma cruzi invasion

    Directory of Open Access Journals (Sweden)

    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.

  7. Serodiagnosis of bovine trypanosomosis caused by non-tsetse transmitted Trypanosoma (Duttonella) vivax parasites using the soluble form of a Trypanozoon variant surface glycoprotein antigen.

    Science.gov (United States)

    Uzcanga, Graciela L; Pérez-Rojas, Yenis; Camargo, Rocío; Izquier, Adriana; Noda, José A; Chacín, Ronny; Parra, Nereida; Ron, Lenin; Rodríguez-Hidalgo, Richar; Bubis, José

    2016-03-15

    Previous studies have shown that a 64-kDa antigen (p64) that was purified from the Venezuelan TeAp-N/D1 isolate of Trypanosoma (Trypanozoon) equiperdum corresponds to the soluble form of its predominant variant surface glycoprotein (VSG), and exhibited cross-reactivity with Trypanosoma (Duttonella) vivax. The course of experimental acute infections of bovines with T. vivax were followed by measuring whole anti-p64 antibodies and specific anti-p64 IgG and IgM antibodies in animal sera by indirect enzyme-linked immunosorbent assay (ELISA). The value of p64 to diagnose bovine trypanosomosis was also examined using 350 sera from healthy and T. vivax-infected cows living in a trypanosomosis-endemic and enzootic stable area, and 48 sera obtained during a trypanosomosis outbreak. Serological assays showed that ∼ 70-80% of the infected sera contained anti-p64 antibodies, based on the comparative immunodetection of the T. equiperdum clarified antigenic fraction used as a reference test. In the absence of a gold standard, Bayesian analysis for multiple testing estimated a sensitivity and specificity of 71.6% and 98.8%, respectively, for the indirect ELISA using p64 as antigen. An apparent prevalence of 37.7% for bovine trypanosomosis infection was also estimated with a Bayesian approach when the p64 ELISA test was used. Employing blood from acute infected cows, the indirect ELISA response against p64 was contrasted with the microhematocrit centrifuge method and analyses by polymerase chain reaction (PCR) using specific primers targeting the inter-specific length variation of the internal transcribed spacer 1 region of the 18S ribosomal gene. The efficiency of p64 for the detection of anti-trypanosome antibodies in acute infected bovines was also corroborated serologically by comparing its response to that of the Indonesian Trypanosoma evansi Rode Trypanozoon antigen type (RoTat) 1.2 VSG, which possesses high specificity and sensitivity. As expected, PCR was the best

  8. Flux Analysis of the Trypanosoma brucei Glycolysis Based on a Multiobjective-Criteria Bioinformatic Approach

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    Amine Ghozlane

    2012-01-01

    Full Text Available Trypanosoma brucei is a protozoan parasite of major of interest in discovering new genes for drug targets. This parasite alternates its life cycle between the mammal host(s (bloodstream form and the insect vector (procyclic form, with two divergent glucose metabolism amenable to in vitro culture. While the metabolic network of the bloodstream forms has been well characterized, the flux distribution between the different branches of the glucose metabolic network in the procyclic form has not been addressed so far. We present a computational analysis (called Metaboflux that exploits the metabolic topology of the procyclic form, and allows the incorporation of multipurpose experimental data to increase the biological relevance of the model. The alternatives resulting from the structural complexity of networks are formulated as an optimization problem solved by a metaheuristic where experimental data are modeled in a multiobjective function. Our results show that the current metabolic model is in agreement with experimental data and confirms the observed high metabolic flexibility of glucose metabolism. In addition, Metaboflux offers a rational explanation for the high flexibility in the ratio between final products from glucose metabolism, thsat is, flux redistribution through the malic enzyme steps.

  9. Formas de cultura de Trypanosoma rotatorium Mayer, 1843: isolado da rã Leptodactylus ocellatus do Brasil Culture forms of T. rotatorum Mayer, 1843

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    Neize M. Pereira

    1973-01-01

    Full Text Available Os autores estudaram o comportamento "in vitro" do Trypanosoma encontrado nas rãs brasileiras, visando critérios adicionais na caracterização específica deste grupo. Utilizaram diferentes meios de cultura (NNN, Novy e Mac Neal, SNB 9 de Diamond 1954, Boné & Steinert, 1956 Boné & Parent 1963 e Halevy & Gisry 1964 no isolamento do Trypanosoma rotatorium encontrado com certa freqüência na rã Leptodactylus com larga distribuição na região Neotropical. Observamso que o comportamento do T. rotatorium das rãs desta região em meios de cultura mostra características bem diferentes daquelas observadas com tripanosomas de outras regiões, quer seja pela dificuldade de manutenção em subcultura, quer pelas formas de divisão desenvolvidas. Empregamos os mesmos meios de cultura utilizados nos isolamentos dos tripanosomas de rã da Europa e como pode ser visto no Quadro I os resultados obtidos com material da região Neotropical são concordantes, surgerindo, pelo menos uma variação dentro da espécie.Different culture media were employed to isolate T. rotatorium, a common parasite in the blood of brazilian frog Leptodactylus ocellatus. Although we have isolated the parasite in three different media (SNB-9, Boné Parent and Boné Steinert media, subcultures were not obtained. Theses facts confirm the results also pointed out by Machado 1911 with T. rotatorium from hosts collected in the same region. In accordance with the factes observed in the litterature (see table I in this work our results suggest an important difference between the T. rotatorium of neotropical region and that of the other regions, which are easily cultivated in subcultures. The culture forms present some differential aspects in T. rotatorium mainly by production of "Somatelas".

  10. Lineage Analysis of Circulating Trypanosoma cruzi Parasites and Their Association with Clinical Forms of Chagas Disease in Bolivia

    Science.gov (United States)

    del Puerto, Ramona; Nishizawa, Juan Eiki; Kikuchi, Mihoko; Iihoshi, Naomi; Roca, Yelin; Avilas, Cinthia; Gianella, Alberto; Lora, Javier; Gutierrez Velarde, Freddy Udalrico; Renjel, Luis Alberto; Miura, Sachio; Higo, Hiroo; Komiya, Norihiro; Maemura, Koji; Hirayama, Kenji

    2010-01-01

    Background The causative agent of Chagas disease, Trypanosoma cruzi, is divided into 6 Discrete Typing Units (DTU): Tc I, IIa, IIb, IIc, IId and IIe. In order to assess the relative pathogenicities of different DTUs, blood samples from three different clinical groups of chronic Chagas disease patients (indeterminate, cardiac, megacolon) from Bolivia were analyzed for their circulating parasites lineages using minicircle kinetoplast DNA polymorphism. Methods and Findings Between 2000 and 2007, patients sent to the Centro Nacional de Enfermedades Tropicales for diagnosis of Chagas from clinics and hospitals in Santa Cruz, Bolivia, were assessed by serology, cardiology and gastro-intestinal examinations. Additionally, patients who underwent colonectomies due to Chagasic magacolon at the Hospital Universitario Japonés were also included. A total of 306 chronic Chagas patients were defined by their clinical types (81 with cardiopathy, 150 without cardiopathy, 100 with megacolon, 144 without megacolon, 164 with cardiopathy or megacolon, 73 indeterminate and 17 cases with both cardiopathy and megacolon). DNA was extracted from 10 ml of peripheral venous blood for PCR analysis. The kinetoplast minicircle DNA (kDNA) was amplified from 196 out of 306 samples (64.1%), of which 104 (53.3%) were Tc IId, 4 (2.0%) Tc I, 7 (3.6%) Tc IIb, 1 (0.5%) Tc IIe, 26 (13.3%) Tc I/IId, 1 (0.5%) Tc I/IIb/IId, 2 (1.0%) Tc IIb/d and 51 (25.9%) were unidentified. Of the 133 Tc IId samples, three different kDNA hypervariable region patterns were detected; Mn (49.6%), TPK like (48.9%) and Bug-like (1.5%). There was no significant association between Tc types and clinical manifestations of disease. Conclusions None of the identified lineages or sublineages was significantly associated with any particular clinical manifestations in the chronic Chagas patients in Bolivia. PMID:20502516

  11. The Combination of Vitamin K3 and Vitamin C Has Synergic Activity against Forms of Trypanosoma cruzi through a Redox Imbalance Process.

    Science.gov (United States)

    Cristina Desoti, Vânia; Lazarin-Bidóia, Danielle; Martins Ribeiro, Fabianne; Cardoso Martins, Solange; da Silva Rodrigues, Jean Henrique; Ueda-Nakamura, Tania; Vataru Nakamura, Celso; Farias Ximenes, Valdecir; de Oliveira Silva, Sueli

    2015-01-01

    Chagas' disease is an infection that is caused by the protozoan Trypanosoma cruzi, affecting millions of people worldwide. Because of severe side effects and variable efficacy, the current treatments for Chagas' disease are unsatisfactory, making the search for new chemotherapeutic agents essential. Previous studies have reported various biological activities of naphthoquinones, such as the trypanocidal and antitumor activity of vitamin K3. The combination of this vitamin with vitamin C exerted better effects against various cancer cells than when used alone. These effects have been attributed to an increase in reactive oxygen species generation. In the present study, we evaluated the activity of vitamin K3 and vitamin C, alone and in combination, against T. cruzi. The vitamin K3 + vitamin C combination exerted synergistic effects against three forms of T. cruzi, leading to morphological, ultrastructural, and functional changes by producing reactive species, decreasing reduced thiol groups, altering the cell cycle, causing lipid peroxidation, and forming autophagic vacuoles. Our hypothesis is that the vitamin K3 + vitamin C combination induces oxidative imbalance in T. cruzi, probably started by a redox cycling process that leads to parasite cell death.

  12. The Combination of Vitamin K3 and Vitamin C Has Synergic Activity against Forms of Trypanosoma cruzi through a Redox Imbalance Process.

    Directory of Open Access Journals (Sweden)

    Vânia Cristina Desoti

    Full Text Available Chagas' disease is an infection that is caused by the protozoan Trypanosoma cruzi, affecting millions of people worldwide. Because of severe side effects and variable efficacy, the current treatments for Chagas' disease are unsatisfactory, making the search for new chemotherapeutic agents essential. Previous studies have reported various biological activities of naphthoquinones, such as the trypanocidal and antitumor activity of vitamin K3. The combination of this vitamin with vitamin C exerted better effects against various cancer cells than when used alone. These effects have been attributed to an increase in reactive oxygen species generation. In the present study, we evaluated the activity of vitamin K3 and vitamin C, alone and in combination, against T. cruzi. The vitamin K3 + vitamin C combination exerted synergistic effects against three forms of T. cruzi, leading to morphological, ultrastructural, and functional changes by producing reactive species, decreasing reduced thiol groups, altering the cell cycle, causing lipid peroxidation, and forming autophagic vacuoles. Our hypothesis is that the vitamin K3 + vitamin C combination induces oxidative imbalance in T. cruzi, probably started by a redox cycling process that leads to parasite cell death.

  13. Identification and characterization of a stage specific membrane protein involved in flagellar attachment in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Katherine Woods

    Full Text Available Flagellar attachment is a visibly striking morphological feature of African trypanosomes but little is known about the requirements for attachment at a molecular level. This study characterizes a previously undescribed membrane protein, FLA3, which plays an essential role in flagellar attachment in Trypanosoma brucei. FLA3 is heavily N-glycosylated, locates to the flagellar attachment zone and appears to be a bloodstream stage specific protein. Ablation of the FLA3 mRNA rapidly led to flagellar detachment and a concomitant failure of cytokinesis in the long slender bloodstream form but had no effect on the procyclic form. Flagellar detachment was obvious shortly after induction of the dsRNA and the newly synthesized flagellum was often completely detached after it emerged from the flagellar pocket. Within 12 h most cells possessed detached flagella alongside the existing attached flagellum. These results suggest that proteins involved in attachment are not shared between the new and old attachment zones. In other respects the detached flagella appear normal, they beat rapidly although directional motion was lost, and they possess an apparently normal axoneme and paraflagellar rod structure. The flagellar attachment zone appeared to be disrupted when FLA3 was depleted. Thus, while flagellar attachment is a constitutive feature of the life cycle of trypanosomes, attachment requires stage specific elements at the protein level.

  14. A dominant negative form of inositol 1,4,5-trisphosphate receptor induces metacyclogenesis and increases mitochondrial density in Trypanosoma cruzi

    International Nuclear Information System (INIS)

    Hashimoto, Muneaki; Nara, Takeshi; Enomoto, Masahiro; Kurebayashi, Nagomi; Yoshida, Mitsutaka; Sakurai, Takashi; Mita, Toshihiro; Mikoshiba, Katsuhiko

    2015-01-01

    Inositol 1,4,5-trisphosphate receptor (IP_3R) is a key regulator of intracellular Ca"2"+ concentration that release Ca"2"+ from Ca"2"+ stores in response to various external stimuli. IP_3R also works as a signal hub which form a platform for interacting with various proteins involved in diverse cell signaling. Previously, we have identified an IP_3R homolog in the parasitic protist, Trypanosoma cruzi (TcIP_3R). Parasites expressing reduced or increased levels of TcIP_3R displayed defects in growth, transformation, and infectivity. In the present study, we established parasitic strains expressing a dominant negative form of TcIP_3R, named DN-TcIP_3R, to further investigate the physiological role(s) of TcIP_3R. We found that the growth of epimastigotes expressing DN-TcIP_3R was significantly slower than that of parasites with TcIP_3R expression levels that were approximately 65% of wild-type levels. The expression of DN-TcIP_3R in epimastigotes induced metacyclogenesis even in the normal growth medium. Furthermore, these epimastigotes showed the presence of dense mitochondria under a transmission electron microscope. Our findings confirm that TcIP_3R is crucial for epimastigote growth, as previously reported. They also suggest that a strong inhibition of the IP_3R-mediated signaling induces metacyclogenesis and that mitochondrial integrity is closely associated with this signaling. - Highlights: • We established T. cruzi strains expressing a dominant negative form of the TcIP_3R. • DN-TcIP_3R expression inhibits epimastigote growth and induces metacyclogenesis. • Microscopic analysis indicated TcIP_3R role in maintaining mitochondrial integrity. • Growth, but not microbial density, was altered by mammalian IP_3R inhibitor (2-APB).

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

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    Maria P. Deane

    1984-12-01

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

  16. Inhibitors of the mitochondrial cytochrome b-c1 complex inhibit the cyanide-insensitive respiration of Trypanosoma brucei.

    Science.gov (United States)

    Turrens, J F; Bickar, D; Lehninger, A L

    1986-06-01

    The cyanide-insensitive respiration of bloodstream trypomastigote forms of Trypanosoma brucei (75 +/- 8 nmol O2 min-1(mg protein)-1) is completely inhibited by the mitochondrial ubiquinone-like inhibitors 2-hydroxy-3-undecyl-1,4-naphthoquinone (UHNQ) and 5-n-undecyl-6-hydroxy-4,7-dioxobenzothiazole (UHDBT). The Ki values for UHDBT (30 nM) and UHNQ (2 microM) are much lower than the reported Ki for salicylhydroxamic acid (SHAM) (5 microM), a widely used inhibitor of the cyanide-insensitive oxidase. UHNQ also stimulated the glycerol-3-phosphate-dependent reduction of phenazine methosulfate, demonstrating that the site of UHNQ inhibition is on the terminal oxidase of the cyanide-insensitive respiration of T. brucei. These results suggest that a ubiquinone-like compound may act as an electron carrier between the two enzymatic components of the cyanide-insensitive glycerol-3-phosphate oxidase.

  17. A dominant negative form of inositol 1,4,5-trisphosphate receptor induces metacyclogenesis and increases mitochondrial density in Trypanosoma cruzi

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Muneaki, E-mail: muneaki@juntendo.ac.jp [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Nara, Takeshi, E-mail: tnara@juntendo.ac.jp [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Enomoto, Masahiro, E-mail: menomoto@uhnres.utoronto.ca [Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Saitama, 351-0198 (Japan); Princess Margaret Cancer Centre, Department of Medical Biophysics, University of Toronto, M5G1L7, Toronto, Ontario (Canada); Kurebayashi, Nagomi, E-mail: nagomik@juntendo.ac.jp [Department of Pharmacology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, 113-8421 (Japan); Yoshida, Mitsutaka, E-mail: myoshida@juntendo.ac.jp [Laboratoly of Morphology and Image Analysis, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Sakurai, Takashi, E-mail: tsakurai@juntendo.ac.jp [Department of Pharmacology, Juntendo University School of Medicine, Bunkyo-ku, Tokyo, 113-8421 (Japan); Mita, Toshihiro, E-mail: tmita@juntendo.ac.jp [Department of Molecular and Cellular Parasitology, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421 (Japan); Mikoshiba, Katsuhiko, E-mail: mikosiba@brain.riken.jp [Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Saitama, 351-0198 (Japan); Calcium Oscillation Project, International Cooperative Research Project and Solution-Oriented Research for Science and Technology, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012 (Japan)

    2015-10-23

    Inositol 1,4,5-trisphosphate receptor (IP{sub 3}R) is a key regulator of intracellular Ca{sup 2+} concentration that release Ca{sup 2+} from Ca{sup 2+} stores in response to various external stimuli. IP{sub 3}R also works as a signal hub which form a platform for interacting with various proteins involved in diverse cell signaling. Previously, we have identified an IP{sub 3}R homolog in the parasitic protist, Trypanosoma cruzi (TcIP{sub 3}R). Parasites expressing reduced or increased levels of TcIP{sub 3}R displayed defects in growth, transformation, and infectivity. In the present study, we established parasitic strains expressing a dominant negative form of TcIP{sub 3}R, named DN-TcIP{sub 3}R, to further investigate the physiological role(s) of TcIP{sub 3}R. We found that the growth of epimastigotes expressing DN-TcIP{sub 3}R was significantly slower than that of parasites with TcIP{sub 3}R expression levels that were approximately 65% of wild-type levels. The expression of DN-TcIP{sub 3}R in epimastigotes induced metacyclogenesis even in the normal growth medium. Furthermore, these epimastigotes showed the presence of dense mitochondria under a transmission electron microscope. Our findings confirm that TcIP{sub 3}R is crucial for epimastigote growth, as previously reported. They also suggest that a strong inhibition of the IP{sub 3}R-mediated signaling induces metacyclogenesis and that mitochondrial integrity is closely associated with this signaling. - Highlights: • We established T. cruzi strains expressing a dominant negative form of the TcIP{sub 3}R. • DN-TcIP{sub 3}R expression inhibits epimastigote growth and induces metacyclogenesis. • Microscopic analysis indicated TcIP{sub 3}R role in maintaining mitochondrial integrity. • Growth, but not microbial density, was altered by mammalian IP{sub 3}R inhibitor (2-APB).

  18. The Combination of Vitamin K3 and Vitamin C Has Synergic Activity against Forms of Trypanosoma cruzi through a Redox Imbalance Process

    OpenAIRE

    Cristina Desoti, V?nia; Lazarin-Bid?ia, Danielle; Martins Ribeiro, Fabianne; Cardoso Martins, Solange; da Silva Rodrigues, Jean Henrique; Ueda-Nakamura, Tania; Vataru Nakamura, Celso; Farias Ximenes, Valdecir; de Oliveira Silva, Sueli

    2015-01-01

    Chagas' disease is an infection that is caused by the protozoan Trypanosoma cruzi, affecting millions of people worldwide. Because of severe side effects and variable efficacy, the current treatments for Chagas' disease are unsatisfactory, making the search for new chemotherapeutic agents essential. Previous studies have reported various biological activities of naphthoquinones, such as the trypanocidal and antitumor activity of vitamin K3. The combination of this vitamin with vitamin C exert...

  19. Trypanosoma brucei TbIF1 inhibits the essential Finf1/inf-ATPase in the infectious form of the parasite

    Czech Academy of Sciences Publication Activity Database

    Panicucci, Brian; Gahura, Ondřej; Zíková, Alena

    2017-01-01

    Roč. 11, č. 4 (2017), č. článku e0005552. ISSN 1935-2735 R&D Projects: GA MŠk(CZ) EE2.3.30.0032; GA ČR GA17-22248S; GA MŠk LL1205 Institutional support: RVO:60077344 Keywords : mt * TblF1 * Trypanosoma brucei Subject RIV: EE - Microbiology, Virology OBOR OECD: Infectious Diseases Impact factor: 3.834, year: 2016

  20. 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.

  1. Stearoyl-CoA desaturase is an essential enzyme for the parasitic protist Trypanosoma brucei

    Energy Technology Data Exchange (ETDEWEB)

    Alloatti, Andres [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina); Gupta, Shreedhara; Gualdron-Lopez, Melisa; Nguewa, Paul A. [Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Universite Catholique de Louvain, Brussels (Belgium); Altabe, Silvia G. [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina); Deumer, Gladys; Wallemacq, Pierre [Department of Clinical Chemistry, Cliniques Universitaires Saint-Luc, LTAP, Universite Catholique de Louvain, Brussels (Belgium); Michels, Paul A.M. [Research Unit for Tropical Diseases, de Duve Institute and Laboratory of Biochemistry, Universite Catholique de Louvain, Brussels (Belgium); Uttaro, Antonio D., E-mail: toniuttaro@yahoo.com.ar [Instituto de Biologia Molecular y Celular de Rosario (IBR), CONICET, Facultad de Ciencias Bioquimicas y Farmaceuticas, Universidad Nacional de Rosario, Santa Fe (Argentina)

    2011-08-26

    Highlights: {yields} Inhibiting {Delta}9 desaturase drastically changes T. brucei's fatty-acid composition. {yields} Isoxyl specifically inhibits the {Delta}9 desaturase causing a growth arrest. {yields} RNA interference of desaturase expression causes a similar effect. {yields} Feeding T. brucei-infected mice with Isoxyl decreases the parasitemia. {yields} 70% of Isoxyl-treated mice survived the trypanosome infection. -- Abstract: Trypanosoma brucei, the etiologic agent of sleeping sickness, is exposed to important changes in nutrients and temperature during its life cycle. To adapt to these changes, the fluidity of its membranes plays a crucial role. This fluidity, mediated by the fatty-acid composition, is regulated by enzymes named desaturases. We have previously shown that the oleoyl desaturase is essential for Trypanosoma cruzi and T. brucei. In this work, we present experimental support for the relevance of stearoyl-CoA desaturase (SCD) for T. brucei's survival, in both its insect or procyclic-form (PCF) and bloodstream-form (BSF) stages. We evaluated this essentiality in two different ways: by generating a SCD knocked-down parasite line using RNA interference, and by chemical inhibition of the enzyme with two compounds, Isoxyl and a thiastearate with the sulfur atom at position 10 (10-TS). The effective concentration for 50% growth inhibition (EC{sub 50}) of PCF was 1.0 {+-} 0.2 {mu}M for Isoxyl and 5 {+-} 2 {mu}M for 10-TS, whereas BSF appeared more susceptible with EC{sub 50} values 0.10 {+-} 0.03 {mu}M (Isoxyl) and 1.0 {+-} 0.6 {mu}M (10-TS). RNA interference showed to be deleterious for both stages of the parasite. In addition, T. brucei-infected mice were fed with Isoxyl, causing a reduction of the parasitemia and an increase of the rodents' survival.

  2. Stearoyl-CoA desaturase is an essential enzyme for the parasitic protist Trypanosoma brucei

    International Nuclear Information System (INIS)

    Alloatti, Andres; Gupta, Shreedhara; Gualdron-Lopez, Melisa; Nguewa, Paul A.; Altabe, Silvia G.; Deumer, Gladys; Wallemacq, Pierre; Michels, Paul A.M.; Uttaro, Antonio D.

    2011-01-01

    Highlights: → Inhibiting Δ9 desaturase drastically changes T. brucei's fatty-acid composition. → Isoxyl specifically inhibits the Δ9 desaturase causing a growth arrest. → RNA interference of desaturase expression causes a similar effect. → Feeding T. brucei-infected mice with Isoxyl decreases the parasitemia. → 70% of Isoxyl-treated mice survived the trypanosome infection. -- Abstract: Trypanosoma brucei, the etiologic agent of sleeping sickness, is exposed to important changes in nutrients and temperature during its life cycle. To adapt to these changes, the fluidity of its membranes plays a crucial role. This fluidity, mediated by the fatty-acid composition, is regulated by enzymes named desaturases. We have previously shown that the oleoyl desaturase is essential for Trypanosoma cruzi and T. brucei. In this work, we present experimental support for the relevance of stearoyl-CoA desaturase (SCD) for T. brucei's survival, in both its insect or procyclic-form (PCF) and bloodstream-form (BSF) stages. We evaluated this essentiality in two different ways: by generating a SCD knocked-down parasite line using RNA interference, and by chemical inhibition of the enzyme with two compounds, Isoxyl and a thiastearate with the sulfur atom at position 10 (10-TS). The effective concentration for 50% growth inhibition (EC 50 ) of PCF was 1.0 ± 0.2 μM for Isoxyl and 5 ± 2 μM for 10-TS, whereas BSF appeared more susceptible with EC 50 values 0.10 ± 0.03 μM (Isoxyl) and 1.0 ± 0.6 μM (10-TS). RNA interference showed to be deleterious for both stages of the parasite. In addition, T. brucei-infected mice were fed with Isoxyl, causing a reduction of the parasitemia and an increase of the rodents' survival.

  3. RNA-Seq analysis validates the use of culture-derived Trypanosoma brucei and provides new markers for mammalian and insect life-cycle stages.

    Science.gov (United States)

    Naguleswaran, Arunasalam; Doiron, Nicholas; Roditi, Isabel

    2018-04-02

    Trypanosoma brucei brucei, the parasite causing Nagana in domestic animals, is closely related to the parasites causing sleeping sickness, but does not infect humans. In addition to its importance as a pathogen, the relative ease of genetic manipulation and an innate capacity for RNAi extend its use as a model organism in cell and infection biology. During its development in its mammalian and insect (tsetse fly) hosts, T. b. brucei passes through several different life-cycle stages. There are currently four life-cycle stages that can be cultured: slender forms and stumpy forms, which are equivalent to forms found in the mammal, and early and late procyclic forms, which are equivalent to forms in the tsetse midgut. Early procyclic forms show coordinated group movement (social motility) on semi-solid surfaces, whereas late procyclic forms do not. RNA-Seq was performed on biological replicates of each life-cycle stage. These constitute the first datasets for culture-derived slender and stumpy bloodstream forms and early and late procyclic forms. Expression profiles confirmed that genes known to be stage-regulated in the animal and insect hosts were also regulated in culture. Sequence reads of 100-125 bases provided sufficient precision to uncover differential expression of closely related genes. More than 100 transcripts showed peak expression in stumpy forms, including adenylate cyclases and several components of inositol metabolism. Early and late procyclic forms showed differential expression of 73 transcripts, a number of which encoded proteins that were previously shown to be stage-regulated. Moreover, two adenylate cyclases previously shown to reduce social motility are up-regulated in late procyclic forms. This study validates the use of cultured bloodstream forms as alternatives to animal-derived parasites and yields new markers for all four stages. In addition to underpinning recent findings that early and late procyclic forms are distinct life-cycle stages

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

    Science.gov (United States)

    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

  5. Differential Editosome Protein Function between Life Cycle Stages of Trypanosoma brucei.

    Science.gov (United States)

    McDermott, Suzanne M; Guo, Xuemin; Carnes, Jason; Stuart, Kenneth

    2015-10-09

    Uridine insertion and deletion RNA editing generates functional mitochondrial mRNAs in Trypanosoma brucei. The mRNAs are differentially edited in bloodstream form (BF) and procyclic form (PF) life cycle stages, and this correlates with the differential utilization of glycolysis and oxidative phosphorylation between the stages. The mechanism that controls this differential editing is unknown. Editing is catalyzed by multiprotein ∼20S editosomes that contain endonuclease, 3'-terminal uridylyltransferase, exonuclease, and ligase activities. These editosomes also contain KREPB5 and KREPA3 proteins, which have no functional catalytic motifs, but they are essential for parasite viability, editing, and editosome integrity in BF cells. We show here that repression of KREPB5 or KREPA3 is also lethal in PF, but the effects on editosome structure differ from those in BF. In addition, we found that point mutations in KREPB5 or KREPA3 differentially affect cell growth, editosome integrity, and RNA editing between BF and PF stages. These results indicate that the functions of KREPB5 and KREPA3 editosome proteins are adjusted between the life cycle stages. This implies that these proteins are involved in the processes that control differential editing and that the 20S editosomes differ between the life cycle stages. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. Blocking variant surface glycoprotein synthesis alters endoplasmic reticulum exit sites/Golgi homeostasis in Trypanosoma brucei.

    Science.gov (United States)

    Ooi, Cher-Pheng; Smith, Terry K; Gluenz, Eva; Wand, Nadina Vasileva; Vaughan, Sue; Rudenko, Gloria

    2018-06-01

    The predominant secretory cargo of bloodstream form Trypanosoma brucei is variant surface glycoprotein (VSG), comprising ~10% total protein and forming a dense protective layer. Blocking VSG translation using Morpholino oligonucleotides triggered a precise pre-cytokinesis arrest. We investigated the effect of blocking VSG synthesis on the secretory pathway. The number of Golgi decreased, particularly in post-mitotic cells, from 3.5 ± 0.6 to 2.0 ± 0.04 per cell. Similarly, the number of endoplasmic reticulum exit sites (ERES) in post-mitotic cells dropped from 3.9 ± 0.6 to 2.7 ± 0.1 eight hours after blocking VSG synthesis. The secretory pathway was still functional in these stalled cells, as monitored using Cathepsin L. Rates of phospholipid and glycosylphosphatidylinositol-anchor biosynthesis remained relatively unaffected, except for the level of sphingomyelin which increased. However, both endoplasmic reticulum and Golgi morphology became distorted, with the Golgi cisternae becoming significantly dilated, particularly at the trans-face. Membrane accumulation in these structures is possibly caused by reduced budding of nascent vesicles due to the drastic reduction in the total amount of secretory cargo, that is, VSG. These data argue that the total flux of secretory cargo impacts upon the biogenesis and maintenance of secretory structures and organelles in T. brucei, including the ERES and Golgi. © 2018 The Authors. Traffic published by John Wiley & Sons Ltd.

  7. Candida Infection of the Bloodstream - Candidemia

    Science.gov (United States)

    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 ...

  8. Trypanosoma melophagium from the sheep ked Melophagus ovinus on the island of St Kilda.

    Science.gov (United States)

    Gibson, W; Pilkington, J G; Pemberton, J M

    2010-10-01

    SUMMARYThe sheep ked has been largely eradicated in the UK but persists in the feral Soay sheep of St Kilda in the Outer Hebrides. Sheep keds transmit Trypanosoma melophagium, but parasitaemias are typically cryptic and this trypanosome has not been recorded in the St Kilda sheep. Trypanosomes were detected by PCR in preserved keds and were also found in gut smears from live keds; one infected gut was used to establish the trypanosome in vitro. Examination of the morphology of bloodstream forms from culture confirmed its identity as T. melophagium. Most keds were found to harbour the trypanosome, particularly those collected from lambs. DNA was extracted from preserved keds and from trypanosomes grown in vitro. Sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene and the spliced leader transcript showed the T. melophagium sequences to be very similar to those from T. theileri. A partial sequence of the ked SSU rRNA gene was also obtained. The close genetic relationship of T. melophagium and T. theileri suggests that T. melophagium represents a lineage of T. theileri that adapted to transmission by sheep keds and hence became a specific parasite of sheep.

  9. Adenylate Cyclases of Trypanosoma brucei, Environmental Sensors and Controllers of Host Innate Immune Response.

    Science.gov (United States)

    Salmon, Didier

    2018-04-25

    Trypanosoma brucei , etiological agent of Sleeping Sickness in Africa, is the prototype of African trypanosomes, protozoan extracellular flagellate parasites transmitted by saliva ( Salivaria ). In these parasites the molecular controls of the cell cycle and environmental sensing are elaborate and concentrated at the flagellum. Genomic analyses suggest that these parasites appear to differ considerably from the host in signaling mechanisms, with the exception of receptor-type adenylate cyclases (AC) that are topologically similar to receptor-type guanylate cyclase (GC) of higher eukaryotes but control a new class of cAMP targets of unknown function, the cAMP response proteins (CARPs), rather than the classical protein kinase A cAMP effector (PKA). T. brucei possesses a large polymorphic family of ACs, mainly associated with the flagellar membrane, and these are involved in inhibition of the innate immune response of the host prior to the massive release of immunomodulatory factors at the first peak of parasitemia. Recent evidence suggests that in T. brucei several insect-specific AC isoforms are involved in social motility, whereas only a few AC isoforms are involved in cytokinesis control of bloodstream forms, attesting that a complex signaling pathway is required for environmental sensing. In this review, after a general update on cAMP signaling pathway and the multiple roles of cAMP, I summarize the existing knowledge of the mechanisms by which pathogenic microorganisms modulate cAMP levels to escape immune defense.

  10. Adenylate Cyclases of Trypanosoma brucei, Environmental Sensors and Controllers of Host Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Didier Salmon

    2018-04-01

    Full Text Available Trypanosoma brucei, etiological agent of Sleeping Sickness in Africa, is the prototype of African trypanosomes, protozoan extracellular flagellate parasites transmitted by saliva (Salivaria. In these parasites the molecular controls of the cell cycle and environmental sensing are elaborate and concentrated at the flagellum. Genomic analyses suggest that these parasites appear to differ considerably from the host in signaling mechanisms, with the exception of receptor-type adenylate cyclases (AC that are topologically similar to receptor-type guanylate cyclase (GC of higher eukaryotes but control a new class of cAMP targets of unknown function, the cAMP response proteins (CARPs, rather than the classical protein kinase A cAMP effector (PKA. T. brucei possesses a large polymorphic family of ACs, mainly associated with the flagellar membrane, and these are involved in inhibition of the innate immune response of the host prior to the massive release of immunomodulatory factors at the first peak of parasitemia. Recent evidence suggests that in T. brucei several insect-specific AC isoforms are involved in social motility, whereas only a few AC isoforms are involved in cytokinesis control of bloodstream forms, attesting that a complex signaling pathway is required for environmental sensing. In this review, after a general update on cAMP signaling pathway and the multiple roles of cAMP, I summarize the existing knowledge of the mechanisms by which pathogenic microorganisms modulate cAMP levels to escape immune defense.

  11. Overproduction, purification, crystallization and preliminary X-ray diffraction analysis of Trypanosoma brucei gambiense glycerol kinase

    International Nuclear Information System (INIS)

    Balogun, Emmanuel Oluwadare; Inaoka, Daniel Ken; Kido, Yasutoshi; Shiba, Tomoo; Nara, Takeshi; Aoki, Takashi; Honma, Teruki; Tanaka, Akiko; Inoue, Masayuki; Matsuoka, Shigeru; Michels, Paul A. M.; Harada, Shigeharu; Kita, Kiyoshi

    2010-01-01

    Glycerol kinase from human African trypanosomes has been purified and crystallized for X-ray structure analysis. In the bloodstream forms of human trypanosomes, glycerol kinase (GK; EC 2.7.1.30) is one of the nine glycosomally compartmentalized enzymes that are essential for energy metabolism. In this study, a recombinant Trypanosoma brucei gambiense GK (rTbgGK) with an N-terminal cleavable His 6 tag was overexpressed, purified to homogeneity and crystallized by the sitting-drop vapour-diffusion method using PEG 400 as a precipitant. A complete X-ray diffraction data set to 2.75 Å resolution indicated that the crystals belonged to the orthorhombic space group P2 1 2 1 2 1 , with unit-cell parameters a = 63.84, b = 121.50, c = 154.59 Å. The presence of two rTbgGK molecules in the asymmetric unit gives a Matthews coefficient (V M ) of 2.5 Å 3 Da −1 , corresponding to 50% solvent content

  12. Taxonomy Icon Data: Trypanosoma brucei [Taxonomy Icon

    Lifescience Database Archive (English)

    Full Text Available Trypanosoma brucei Trypanosoma brucei Trypanosoma_brucei_L.png Trypanosoma_brucei_NL.png Trypanoso...ma_brucei_S.png Trypanosoma_brucei_NS.png http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Trypanoso...ma+brucei&t=L http://biosciencedbc.jp/taxonomy_icon/icon.cgi?i=Trypanosoma+brucei&t=NL http://bioscie...ncedbc.jp/taxonomy_icon/icon.cgi?i=Trypanosoma+brucei&t=S http://biosciencedbc.jp.../taxonomy_icon/icon.cgi?i=Trypanosoma+brucei&t=NS http://togodb.biosciencedbc.jp/togodb/view/taxonomy_icon_comment_en?species_id=121 ...

  13. Identification of compounds with anti-proliferative activity against Trypanosoma brucei brucei strain 427 by a whole cell viability based HTS campaign.

    Directory of Open Access Journals (Sweden)

    Melissa L Sykes

    Full Text Available Human African Trypanosomiasis (HAT is caused by two trypanosome sub-species, Trypanosoma brucei rhodesiense and Trypanosoma brucei gambiense. Drugs available for the treatment of HAT have significant issues related to difficult administration regimes and limited efficacy across species and disease stages. Hence, there is considerable need to find new alternative and less toxic drugs. An approach to identify starting points for new drug candidates is high throughput screening (HTS of large compound library collections. We describe the application of an Alamar Blue based, 384-well HTS assay to screen a library of 87,296 compounds against the related trypanosome subspecies, Trypanosoma brucei brucei bloodstream form lister 427. Primary hits identified against T.b. brucei were retested and the IC(50 value compounds were estimated for T.b. brucei and a mammalian cell line HEK293, to determine a selectivity index for each compound. The screening campaign identified 205 compounds with greater than 10 times selectivity against T.b. brucei. Cluster analysis of these compounds, taking into account chemical and structural properties required for drug-like compounds, afforded a panel of eight compounds for further biological analysis. These compounds had IC(50 values ranging from 0.22 µM to 4 µM with associated selectivity indices ranging from 19 to greater than 345. Further testing against T.b. rhodesiense led to the selection of 6 compounds from 5 new chemical classes with activity against the causative species of HAT, which can be considered potential candidates for HAT early drug discovery. Structure activity relationship (SAR mining revealed components of those hit compound structures that may be important for biological activity. Four of these compounds have undergone further testing to 1 determine whether they are cidal or static in vitro at the minimum inhibitory concentration (MIC, and 2 estimate the time to kill.

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

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    Edilson Nobuyoshi Kaneshima

    2012-10-01

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

  15. 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

  16. 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

  17. Megazol and its bioisostere 4H-1,2,4-triazole: comparing the trypanocidal, cytotoxic and genotoxic activities and their in vitro and in silico interactions with the Trypanosoma brucei nitroreductase enzyme

    Directory of Open Access Journals (Sweden)

    Alcione Silva de Carvalho

    2014-06-01

    Full Text Available Megazol (7 is a 5-nitroimidazole that is highly active against Trypanosoma cruzi and Trypanosoma brucei, as well as drug-resistant forms of trypanosomiasis. Compound 7 is not used clinically due to its mutagenic and genotoxic properties, but has been largely used as a lead compound. Here, we compared the activity of 7 with its 4H-1,2,4-triazole bioisostere (8 in bloodstream forms of T. brucei and T. cruzi and evaluated their activation by T. brucei type I nitroreductase (TbNTR enzyme. We also analysed the cytotoxic and genotoxic effects of these compounds in whole human blood using Comet and fluorescein diacetate/ethidium bromide assays. Although the only difference between 7 and 8 is the substitution of sulphur (in the thiadiazole in 7 for nitrogen (in the triazole in 8, the results indicated that 8 had poorer antiparasitic activity than 7 and was not genotoxic, whereas 7 presented this effect. The determination of Vmax indicated that although 8 was metabolised more rapidly than 7, it bounds to the TbNTR with better affinity, resulting in equivalent kcat/KM values. Docking assays of 7 and 8 performed within the active site of a homology model of the TbNTR indicating that 8 had greater affinity than 7.

  18. Bloodstream Infections with Mycobacterium tuberculosis among HIV patients

    Centers for Disease Control (CDC) Podcasts

    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. 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

  20. 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.

  1. Complete in vitro life cycle of Trypanosoma congolense: development of genetic tools.

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    Virginie Coustou

    Full Text Available BACKGROUND: Animal African trypanosomosis, a disease mainly caused by the protozoan parasite Trypanosoma congolense, is a major constraint to livestock productivity and has a significant impact in the developing countries of Africa. RNA interference (RNAi has been used to study gene function and identify drug and vaccine targets in a variety of organisms including trypanosomes. However, trypanosome RNAi studies have mainly been conducted in T. brucei, as a model for human infection, largely ignoring livestock parasites of economical importance such as T. congolense, which displays different pathogenesis profiles. The whole T. congolense life cycle can be completed in vitro, but this attractive model displayed important limitations: (i genetic tools were currently limited to insect forms and production of modified infectious BSF through differentiation was never achieved, (ii in vitro differentiation techniques lasted several months, (iii absence of long-term bloodstream forms (BSF in vitro culture prevented genomic analyses. METHODOLOGY/PRINCIPAL FINDINGS: We optimized culture conditions for each developmental stage and secured the differentiation steps. Specifically, we devised a medium adapted for the strenuous development of stable long-term BSF culture. Using Amaxa nucleofection technology, we greatly improved the transfection rate of the insect form and designed an inducible transgene expression system using the IL3000 reference strain. We tested it by expression of reporter genes and through RNAi. Subsequently, we achieved the complete in vitro life cycle with dramatically shortened time requirements for various wild type and transgenic strains. Finally, we established the use of modified strains for experimental infections and underlined a host adaptation phase requirement. CONCLUSIONS/SIGNIFICANCE: We devised an improved T. congolense model, which offers the opportunity to perform functional genomics analyses throughout the whole life

  2. Antitrypanosomal compounds from the essential oil and extracts of Keetia leucantha leaves with inhibitor activity on Trypanosoma brucei glyceraldehyde-3-phosphate dehydrogenase.

    Science.gov (United States)

    Bero, J; Beaufay, C; Hannaert, V; Hérent, M-F; Michels, P A; Quetin-Leclercq, J

    2013-02-15

    Keetia leucantha is a West African tree used in traditional medicine to treat several diseases among which parasitic infections. The dichloromethane extract of leaves was previously shown to possess growth-inhibitory activities on Plasmodium falciparum, Trypanosoma brucei brucei and Leishmania mexicana mexicana with low or no cytotoxicity (>100 μg/ml on human normal fibroblasts) (Bero et al. 2009, 2011). In continuation of our investigations on the antitrypanosomal compounds from this dichloromethane extract, we analyzed by GC-FID and GC-MS the essential oil of its leaves obtained by hydrodistillation and the major triterpenic acids in this extract by LC-MS. Twenty-seven compounds were identified in the oil whose percentages were calculated using the normalization method. The essential oil, seven of its constituents and the three triterpenic acids were evaluated for their antitrypanosomal activity on Trypanosoma brucei brucei bloodstream forms (Tbb BSF) and procyclic forms (Tbb PF) to identify an activity on the glycolytic process of trypanosomes. The oil showed an IC(50) of 20.9 μg/ml on Tbb BSF and no activity was observed on Tbb PF. The best antitrypanosomal activity was observed for ursolic acid with IC(50) of 2.5 and 6.5 μg/ml respectively on Tbb BSF and Tbb PF. The inhibitory activity on a glycolytic enzyme of T. brucei, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), was also evaluated for betulinic acid, olenaolic acid, ursolic acid, phytol, α-ionone and β-ionone. The three triterpenic acids and β-ionone showed inhibitory activities on GAPDH with oleanolic acid being the most active with an inhibition of 72.63% at 20 μg/ml. This paper reports for the first time the composition and antitrypanosomal activity of the essential oil of Keetia leucantha. Several of its constituents and three triterpenic acids present in the dichloromethane leaves extract showed a higher antitrypanosomal activity on bloodstream forms of Tbb as compared to procyclic forms

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

    Directory of Open Access Journals (Sweden)

    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

  4. 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.

  5. 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

  6. Phylogenetic position of the giant anuran trypanosomes Trypanosoma chattoni, Trypanosoma fallisi, Trypanosoma mega, Trypanosoma neveulemairei, and Trypanosoma ranarum inferred from 18S rRNA gene sequences.

    Science.gov (United States)

    Martin, Donald S; Wright, André-Denis G; Barta, John R; Desser, Sherwin S

    2002-06-01

    Phylogenetic relationships within the kinetoplastid flagellates were inferred from comparisons of small-subunit ribosomal RNA gene sequences. These included 5 new gene sequences, Trypanosoma fallisi (2,239 bp), Trypanosoma chattoni (2,180 bp), Trypanosoma mega (2,211 bp), Trypanosoma neveulemairei (2,197 bp), and Trypanosoma ranarum (2,203 bp). Trees produced using maximum-parsimony and distance-matrix methods (least-squares, neighbor-joining, and maximum-likelihood), supported by strong bootstrap and quartet-puzzle analyses, indicated that the trypanosomes are a monophyletic group that divides into 2 major lineages, the salivarian trypanosomes and the nonsalivarian trypanosomes. The nonsalivarian trypanosomes further divide into 2 lineages, 1 containing trypanosomes of birds, mammals, and reptiles and the other containing trypanosomes of fish, reptiles, and anurans. Among the giant trypanosomes, T. chattoni is clearly shown to be distantly related to all the other anuran trypanosome species. Trypanosoma mega is closely associated with T. fallisi and T. ranarum, whereas T. neveulemairei and Trypanosoma rotatorium are sister taxa. The branching order of the anuran trypanosomes suggests that some toad trypanosomes may have evolved by host switching from frogs to toads.

  7. The haemoculture of Trypanosoma minasense chagas, 1908

    Directory of Open Access Journals (Sweden)

    Mariangela Ziccardi

    1996-08-01

    Full Text Available Trypanosoma minasense was isolated for the first time in blood axenic culture from a naturally infected marmoset, Callithrix penicillata, from Brazil. The parasite grew profusely in an overlay of Roswell Park Memorial Institute medium plus 20% foetal bovine serum, on Novy, McNeal and Nicolle medium (NNN , at 27°C, with a peak around 168 hr. The morphometry of cultural forms of T. minasense, estimates of cell population size and comparative growth in four different media overlays always with NNN, were studied. The infectivity of cultural forms to marmosets (C. penicillata and C. jacchus and transformation of epimastigotes into metacyclic-like forms in axenic culture in the presence of chitin derivates (chitosan were evaluated.

  8. Spliced leader RNA silencing (SLS - a programmed cell death pathway in Trypanosoma brucei that is induced upon ER stress

    Directory of Open Access Journals (Sweden)

    Michaeli Shulamit

    2012-05-01

    Full Text Available Abstract Trypanosoma brucei is the causative agent of African sleeping sickness. The parasite cycles between its insect (procyclic form and mammalian hosts (bloodstream form. Trypanosomes lack conventional transcription regulation, and their genes are transcribed in polycistronic units that are processed by trans-splicing and polyadenylation. In trans-splicing, which is essential for processing of each mRNA, an exon, the spliced leader (SL is added to all mRNAs from a small RNA, the SL RNA. Trypanosomes lack the machinery for the unfolded protein response (UPR, which in other eukaryotes is induced under endoplasmic reticulum (ER stress. Trypanosomes respond to such stress by changing the stability of mRNAs, which are essential for coping with the stress. However, under severe ER stress that is induced by blocking translocation of proteins to the ER, treatment of cells with chemicals that induce misfolding in the ER, or extreme pH, trypanosomes elicit the spliced leader silencing (SLS pathway. In SLS, the transcription of the SL RNA gene is extinguished, and tSNAP42, a specific SL RNA transcription factor, fails to bind to its cognate promoter. SLS leads to complete shut-off of trans-splicing. In this review, I discuss the UPR in mammals and compare it to the ER stress response in T. brucei leading to SLS. I summarize the evidence supporting the notion that SLS is a programmed cell death (PCD pathway that is utilized by the parasites to substitute for the apoptosis observed in higher eukaryotes under prolonged ER stress. I present the hypothesis that SLS evolved to expedite the death process, and rapidly remove from the population unfit parasites that, by elimination via SLS, cause minimal damage to the parasite population.

  9. Telomeric expression sites are highly conserved in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Christiane Hertz-Fowler

    Full Text Available Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs. The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology.

  10. The morphology of ovine Trypanosoma melophagium (zoomastigophorea: kinetoplastida).

    Science.gov (United States)

    Büscher, G; Friedhoff, K T

    1984-02-01

    Morphologic and biometric data on bloodstream stages of Trypanosoma melophagium are presented. An increasing parasitemia with 111 trypomastigote stages of T. melophagium were found in Giemsa-stained thin blood smears taken from a splenectomized, cortisone-treated sheep recently infested with Melophagus ovinus infected with T. melophagium . The arithmetic mean and standard deviation in micron of the distances between posterior end and kinetoplast were 14.7 and 2.9, from the kinetoplastic to the center of the nucleus 5.1 and 1.1, and from there to the anterior end 19.5 and 1.9. The free flagellum measured 6.0 microns +/- 1.6 microns. The median and the range of the central 70% of values (median +/- 35%) of the nuclear index were 1.1 and 0.9-1.2 and of the kinetoplastic index 3.8 and 3.3-4.9. The same data in microns for the maximal width were 3.1 and 2.1-4.6, and for the width at the level of the nucleus 2.9 and 2.2-4.6. The larger and smaller diameters of the nucleus measured 2.6 (2.2-3.7) micron and 1.7 (1.3-1.7) micron, respectively. The corresponding kinetoplast diameters were 1.1 (0.9-1.3) microns and 0.9 (0.6-0.9) micron, respectively.

  11. 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...

  12. Profiling the anti-protozoal activity of anti-cancer HDAC inhibitors against Plasmodium and Trypanosoma parasites.

    Science.gov (United States)

    Engel, Jessica A; Jones, Amy J; Avery, Vicky M; Sumanadasa, Subathdrage D M; Ng, Susanna S; Fairlie, David P; Skinner-Adams, Tina; Andrews, Katherine T

    2015-12-01

    Histone deacetylase (HDAC) enzymes work together with histone acetyltransferases (HATs) to reversibly acetylate both histone and non-histone proteins. As a result, these enzymes are involved in regulating chromatin structure and gene expression as well as other important cellular processes. HDACs are validated drug targets for some types of cancer, with four HDAC inhibitors clinically approved. However, they are also showing promise as novel drug targets for other indications, including malaria and other parasitic diseases. In this study the in vitro activity of four anti-cancer HDAC inhibitors was examined against parasites that cause malaria and trypanosomiasis. Three of these inhibitors, suberoylanilide hydroxamic acid (SAHA; vorinostat(®)), romidepsin (Istodax(®)) and belinostat (Beleodaq(®)), are clinically approved for the treatment of T-cell lymphoma, while the fourth, panobinostat, has recently been approved for combination therapy use in certain patients with multiple myeloma. All HDAC inhibitors were found to inhibit the growth of asexual-stage Plasmodium falciparum malaria parasites in the nanomolar range (IC50 10-200 nM), while only romidepsin was active at sub-μM concentrations against bloodstream form Trypanosoma brucei brucei parasites (IC50 35 nM). The compounds were found to have some selectivity for malaria parasites compared with mammalian cells, but were not selective for trypanosome parasites versus mammalian cells. All compounds caused hyperacetylation of histone and non-histone proteins in P. falciparum asexual stage parasites and inhibited deacetylase activity in P. falciparum nuclear extracts in addition to recombinant PfHDAC1 activity. P. falciparum histone hyperacetylation data indicate that HDAC inhibitors may differentially affect the acetylation profiles of histone H3 and H4.

  13. Functional and structural insights revealed by molecular dynamics simulations of an essential RNA editing ligase in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Rommie E Amaro

    2007-11-01

    Full Text Available RNA editing ligase 1 (TbREL1 is required for the survival of both the insect and bloodstream forms of Trypanosoma brucei, the parasite responsible for the devastating tropical disease African sleeping sickness. The type of RNA editing that TbREL1 is involved in is unique to the trypanosomes, and no close human homolog is known to exist. In addition, the high-resolution crystal structure revealed several unique features of the active site, making this enzyme a promising target for structure-based drug design. In this work, two 20 ns atomistic molecular dynamics (MD simulations are employed to investigate the dynamics of TbREL1, both with and without the ATP substrate present. The flexibility of the active site, dynamics of conserved residues and crystallized water molecules, and the interactions between TbREL1 and the ATP substrate are investigated and discussed in the context of TbREL1's function. Differences in local and global motion upon ATP binding suggest that two peripheral loops, unique to the trypanosomes, may be involved in interdomain signaling events. Notably, a significant structural rearrangement of the enzyme's active site occurs during the apo simulations, opening an additional cavity adjacent to the ATP binding site that could be exploited in the development of effective inhibitors directed against this protozoan parasite. Finally, ensemble averaged electrostatics calculations over the MD simulations reveal a novel putative RNA binding site, a discovery that has previously eluded scientists. Ultimately, we use the insights gained through the MD simulations to make several predictions and recommendations, which we anticipate will help direct future experimental studies and structure-based drug discovery efforts against this vital enzyme.

  14. Profiling the anti-protozoal activity of anti-cancer HDAC inhibitors against Plasmodium and Trypanosoma parasites

    Directory of Open Access Journals (Sweden)

    Jessica A. Engel

    2015-12-01

    Full Text Available Histone deacetylase (HDAC enzymes work together with histone acetyltransferases (HATs to reversibly acetylate both histone and non-histone proteins. As a result, these enzymes are involved in regulating chromatin structure and gene expression as well as other important cellular processes. HDACs are validated drug targets for some types of cancer, with four HDAC inhibitors clinically approved. However, they are also showing promise as novel drug targets for other indications, including malaria and other parasitic diseases. In this study the in vitro activity of four anti-cancer HDAC inhibitors was examined against parasites that cause malaria and trypanosomiasis. Three of these inhibitors, suberoylanilide hydroxamic acid (SAHA; vorinostat®, romidepsin (Istodax® and belinostat (Beleodaq®, are clinically approved for the treatment of T-cell lymphoma, while the fourth, panobinostat, has recently been approved for combination therapy use in certain patients with multiple myeloma. All HDAC inhibitors were found to inhibit the growth of asexual-stage Plasmodium falciparum malaria parasites in the nanomolar range (IC50 10–200 nM, while only romidepsin was active at sub-μM concentrations against bloodstream form Trypanosoma brucei brucei parasites (IC50 35 nM. The compounds were found to have some selectivity for malaria parasites compared with mammalian cells, but were not selective for trypanosome parasites versus mammalian cells. All compounds caused hyperacetylation of histone and non-histone proteins in P. falciparum asexual stage parasites and inhibited deacetylase activity in P. falciparum nuclear extracts in addition to recombinant PfHDAC1 activity. P. falciparum histone hyperacetylation data indicate that HDAC inhibitors may differentially affect the acetylation profiles of histone H3 and H4.

  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. When Prostate Cancer Circulates in the Bloodstream

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  18. 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

  19. Single-subunit oligosaccharyltransferases of Trypanosoma brucei display different and predictable peptide acceptor specificities.

    Science.gov (United States)

    Jinnelov, Anders; Ali, Liaqat; Tinti, Michele; Güther, Maria Lucia S; Ferguson, Michael A J

    2017-12-08

    Trypanosoma brucei causes African trypanosomiasis and contains three full-length oligosaccharyltransferase (OST) genes; two of which, Tb STT3A and Tb STT3B, are expressed in the bloodstream form of the parasite. These OSTs have different peptide acceptor and lipid-linked oligosaccharide donor specificities, and trypanosomes do not follow many of the canonical rules developed for other eukaryotic N -glycosylation pathways, raising questions as to the basic architecture and detailed function of trypanosome OSTs. Here, we show by blue-native gel electrophoresis and stable isotope labeling in cell culture proteomics that the Tb STT3A and Tb STT3B proteins associate with each other in large complexes that contain no other detectable protein subunits. We probed the peptide acceptor specificities of the OSTs in vivo using a transgenic glycoprotein reporter system and performed glycoproteomics on endogenous parasite glycoproteins using sequential endoglycosidase H and peptide: N -glycosidase-F digestions. This allowed us to assess the relative occupancies of numerous N -glycosylation sites by endoglycosidase H-resistant N -glycans originating from Man 5 GlcNAc 2 -PP-dolichol transferred by Tb STT3A, and endoglycosidase H-sensitive N -glycans originating from Man 9 GlcNAc 2 -PP-dolichol transferred by Tb STT3B. Using machine learning, we assessed the features that best define Tb STT3A and Tb STT3B substrates in vivo and built an algorithm to predict the types of N -glycan most likely to predominate at all the putative N -glycosylation sites in the parasite proteome. Finally, molecular modeling was used to suggest why Tb STT3A has a distinct preference for sequons containing and/or flanked by acidic amino acid residues. Together, these studies provide insights into how a highly divergent eukaryote has re-wired protein N -glycosylation to provide protein sequence-specific N -glycan modifications. Data are available via ProteomeXchange with identifiers PXD007236, PXD007267

  20. Trypanosoma evansi isolated from capybara (Hidrochaeris hidrochaeris

    Directory of Open Access Journals (Sweden)

    Karina Muñoz

    2001-10-01

    Full Text Available A study was conducted to determine the morphological and biometric characteristics of Trypanosoma isolated from 50 capybaras animals, raised in captivity in the Peruvian Amazon. Trypanosoma was found in 14 blood samples using the microhaematocrit, wide drop, and Giemsa-stain methods and T. evansi was identified through morphological details in all 14 positive samples (the subterminal kinetoplast, the developed undulating membrane, and a long free flagellum were used for the identification of the agent.

  1. 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...

  2. 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...

  3. 21 CFR 866.3870 - Trypanosoma spp. serological reagents.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3870 Trypanosoma... consist of antigens and antisera used in serological tests to identify antibodies to Trypanosoma spp. in...

  4. 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...

  5. 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.

  6. Perspectives on the Trypanosoma cruzi–host cell receptor interactions

    Science.gov (United States)

    Villalta, Fernando; Scharfstein, Julio; Ashton, Anthony W.; Tyler, Kevin M.; Guan, Fangxia; Mukherjee, Shankar; Lima, Maria F.; Alvarez, Sandra; Weiss, Louis M.; Huang, Huan; Machado, Fabiana S.

    2009-01-01

    Chagas disease is caused by the parasite Trypanosoma cruzi. The critical initial event is the interaction of the trypomastigote form of the parasite with host receptors. This review highlights recent observations concerning these interactions. Some of the key receptors considered are those for thromboxane, bradykinin, and for the nerve growth factor TrKA. Other important receptors such as galectin-3, thrombospondin, and laminin are also discussed. Investigation into the molecular biology and cell biology of host receptors for T. cruzi may provide novel therapeutic targets. PMID:19283409

  7. Characterization of plasma menbrane polypeptides of trypanosoma from bats

    OpenAIRE

    Pinho,R. T.; Simone,Giovanni de

    1989-01-01

    Cell surface proteins of Trypanosoma dionisii, Trypanosoma vespertilionis and Trypanosoma sp. (M238) were radiodinated and their distribution both in the detergent-poor (DPP) and dertergent-enriched phase (DRP) was studied using a phase separation technique in Triton X-114 as well as polyacrylamide gel electrophoresis in sodium dodecyl sulphate (SDS-PAGE). Significant differences were observed in the proteins present in the DRP when the three species of trypanosoma were compared. Two major ba...

  8. Differential gene expression during Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    Marco Aurelio Krieger

    1999-09-01

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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Leny S. Filardi

    1984-06-01

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

  11. Cytosolic iron-sulphur protein assembly is functionally conserved and essential in procyclic and bloodstream Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Basu, Somsuvro; Netz, D. J.; Haindrich, A. C.; Herlerth, N.; Lagny, T. J.; Pierik, A. J.; Lill, R.; Lukeš, Julius

    2014-01-01

    Roč. 93, č. 5 (2014), s. 897-910 ISSN 0950-382X R&D Projects: GA ČR(CZ) GAP305/11/2179; GA MŠk LH12104; GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : inducible expression system * Cfd1- Nbp35 complex * DNA metabolism * Fe/S proteins * transfer-RNA * cluster * mitochondrial * maturation * biogenesis * yeast Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.419, year: 2014

  12. 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.

  13. 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...

  14. 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.

  15. Characterization of Trypanosoma brucei gambiense stocks isolated ...

    African Journals Online (AJOL)

    Trypanosoma brucei gambiense was isolated twice from each of 23 patients in Côte d'Ivoire. Genetic characterization using RAPD (Random Primed Amplified Polymorphic DNA) showed additional variability within a given isoenzyme profile (zymodeme), confirming that this fingerprinting method has a higher discriminative ...

  16. Developmental and Ultrastructural Characterization and Phylogenetic Analysis of Trypanosoma herthameyeri n. sp. of Brazilian Leptodactilydae Frogs.

    Science.gov (United States)

    Attias, Márcia; Sato, Lyslaine H; Ferreira, Robson C; Takata, Carmen S A; Campaner, Marta; Camargo, Erney P; Teixeira, Marta M G; de Souza, Wanderley

    2016-09-01

    We described the phylogenetic affiliation, development in cultures and ultrastructural features of a trypanosome of Leptodacylus chaquensis from the Pantanal biome of Brazil. In the inferred phylogeny, this trypanosome nested into the Anura clade of the basal Aquatic clade of Trypanosoma, but was separate from all known species within this clade. This finding enabled us to describe it as Trypanosoma herthameyeri n. sp., which also infects other Leptodacylus species from the Pantanal and Caatinga biomes. Trypanosoma herthameyeri multiplies as small rounded forms clumped together and evolving into multiple-fission forms and rosettes of epimastigotes released as long forms with long flagella; scarce trypomastigotes and glove-like forms are common in stationary-phase cultures. For the first time, a trypanosome from an amphibian was observed by field emission scanning electron microscopy, revealing a cytostome opening, well-developed flagellar lamella, and many grooves in pumpkin-like forms. Transmission electron microscopy showed highly developed Golgi complexes, relaxed catenation of KDNA, and a rich set of spongiome tubules in a regular parallel arrangement to the flagellar pocket as confirmed by electron tomography. Considering the basal position in the phylogenetic tree, developmental and ultrastructural data of T. herthameyeri are valuable for evolutionary studies of trypanosome architecture and cell biology. © 2016 The Author(s) Journal of Eukaryotic Microbiology © 2016 International Society of Protistologists.

  17. Both human ferredoxins equally efficiently rescue ferredoxin deficiency in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Changmai, Piya; Horáková, Eva; Long, Shaojun; Černotíková, Eva; McDonald, Lindsay M.; Bontempi, Esteban J.; Lukeš, Julius

    2013-01-01

    Roč. 89, č. 1 (2013), s. 135-151 ISSN 0950-382X R&D Projects: GA ČR(CZ) GAP305/11/2179; GA MŠk LH12104 Institutional support: RVO:60077344 Keywords : IRON-SULFUR CLUSTERS * CYTOCHROME-C-OXIDASE * BLOOD-STREAM FORM Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.026, year: 2013

  18. 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

  19. Detection of Trypanosoma brucei gambiense and T. b. rhodesiense ...

    African Journals Online (AJOL)

    Detection of Trypanosoma brucei gambiense and T. b. rhodesiense in Glossina fuscipes fuscipes ( Diptera: Glossinidae ) and Stomoxys flies using the polymerase chain reaction (PCR) technique in southern Sudan.

  20. 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.

  1. 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.

  2. 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.

  3. 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)

  4. Trypanosoma brucei mitochondrial respiratome: Composition and organization in procyclic form

    KAUST Repository

    Acestor, Nathalie; Zí ková , Alena; Dalley, Rachel A.; Anupama, Atashi; Panigrahi, Aswini Kumar; Stuart, Kenneth D.

    2011-01-01

    The mitochondrial respiratory chain is comprised of four different protein complexes (I-IV), which are responsible for electron transport and generation of proton gradient in the mitochondrial intermembrane space. This proton gradient is then used

  5. Multiple evolutionary origins of Trypanosoma evansi in Kenya.

    Directory of Open Access Journals (Sweden)

    Christine M Kamidi

    2017-09-01

    Full Text Available Trypanosoma evansi is the parasite causing surra, a form of trypanosomiasis in camels and other livestock, and a serious economic burden in Kenya and many other parts of the world. Trypanosoma evansi transmission can be sustained mechanically by tabanid and Stomoxys biting flies, whereas the closely related African trypanosomes T. brucei brucei and T. b. rhodesiense require cyclical development in tsetse flies (genus Glossina for transmission. In this study, we investigated the evolutionary origins of T. evansi. We used 15 polymorphic microsatellites to quantify levels and patterns of genetic diversity among 41 T. evansi isolates and 66 isolates of T. b. brucei (n = 51 and T. b. rhodesiense (n = 15, including many from Kenya, a region where T. evansi may have evolved from T. brucei. We found that T. evansi strains belong to at least two distinct T. brucei genetic units and contain genetic diversity that is similar to that in T. brucei strains. Results indicated that the 41 T. evansi isolates originated from multiple T. brucei strains from different genetic backgrounds, implying independent origins of T. evansi from T. brucei strains. This surprising finding further suggested that the acquisition of the ability of T. evansi to be transmitted mechanically, and thus the ability to escape the obligate link with the African tsetse fly vector, has occurred repeatedly. These findings, if confirmed, have epidemiological implications, as T. brucei strains from different genetic backgrounds can become either causative agents of a dangerous, cosmopolitan livestock disease or of a lethal human disease, like for T. b. rhodesiense.

  6. 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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  9. Iron-associated biology of Trypanosoma brucei.

    Czech Academy of Sciences Publication Activity Database

    Basu, Somsuvro; Horáková, Eva; Lukeš, Julius

    2016-01-01

    Roč. 1860, č. 2 (2016), s. 363-370 ISSN 0304-4165 R&D Projects: GA ČR(CZ) GA14-23986S; GA ČR GAP305/12/2261; GA MŠk(CZ) EE2.3.30.0032 EU Projects: European Commission(XE) COST Action CM1307; European Commission(XE) 316304 - MODBIOLIN Grant - others:AV ČR(CZ) M200961204 Institutional support: RVO:60077344 Keywords : iron * Fe/S cluster * heme * Trypanosoma * TAO Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.702, year: 2016

  10. Species-specific markers for the differential diagnosis of Trypanosoma cruzi and Trypanosoma rangeli and polymorphisms detection in Trypanosoma rangeli.

    Science.gov (United States)

    Ferreira, Keila Adriana Magalhães; Fajardo, Emanuella Francisco; Baptista, Rodrigo P; Macedo, Andrea Mara; Lages-Silva, Eliane; Ramírez, Luis Eduardo; Pedrosa, André Luiz

    2014-06-01

    Trypanosoma cruzi and Trypanosoma rangeli are kinetoplastid parasites which are able to infect humans in Central and South America. Misdiagnosis between these trypanosomes can be avoided by targeting barcoding sequences or genes of each organism. This work aims to analyze the feasibility of using species-specific markers for identification of intraspecific polymorphisms and as target for diagnostic methods by PCR. Accordingly, primers which are able to specifically detect T. cruzi or T. rangeli genomic DNA were characterized. The use of intergenic regions, generally divergent in the trypanosomatids, and the serine carboxypeptidase gene were successful. Using T. rangeli genomic sequences for the identification of group-specific polymorphisms and a polymorphic AT(n) dinucleotide repeat permitted the classification of the strains into two groups, which are entirely coincident with T. rangeli main lineages, KP1 (+) and KP1 (-), previously determined by kinetoplast DNA (kDNA) characterization. The sequences analyzed totalize 622 bp (382 bp represent a hypothetical protein sequence, and 240 bp represent an anonymous sequence), and of these, 581 (93.3%) are conserved sites and 41 bp (6.7%) are polymorphic, with 9 transitions (21.9%), 2 transversions (4.9%), and 30 (73.2%) insertion/deletion events. Taken together, the species-specific markers analyzed may be useful for the development of new strategies for the accurate diagnosis of infections. Furthermore, the identification of T. rangeli polymorphisms has a direct impact in the understanding of the population structure of this parasite.

  11. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Classical clinical signs in rats experimemtally infected with Trypanosoma brucei

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    Nwoha Rosemary Ijeoma Ogechi

    2015-02-01

    Full Text Available Objective: To investigate clinical signs in Trypanosoma brucei infection in albino rats. Methods: Fourteen rats grouped into 2 with 7 rats in each group were used to determine classical clinical manifestation of Trypanosoma brucei infection in rats. Group A rats were uninfected control and Group B rats were infected with Trypanosoma brucei. Results: Parasitaemia was recorded in Group B by (3.86±0.34 d and the peak of parasitaemia was observed at Day 5 post infection. Classical signs observed included squint eyes, raised whiskers, lethargy, no weight loss, pyrexia, isolation from the other rats, and starry hair coat. Conclusions: These signs could be diagnostic or aid in diagnosis of Trypanosoma brucei infection in rats.

  19. Role of cytokines in Trypanosoma brucei-induced anaemia: A ...

    African Journals Online (AJOL)

    species Trypanosoma brucei that are transmitted by a tsetse fly (Glossina spp.) ... of autologous immunoglobulin antibodies on the red cell surfaces and also to ... development for the detection and management of anaemia in trypanosomiasis.

  20. Exosome secretion affects social motility in Trypanosoma brucei.

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    Dror Eliaz

    2017-03-01

    Full Text Available Extracellular vesicles (EV secreted by pathogens function in a variety of biological processes. Here, we demonstrate that in the protozoan parasite Trypanosoma brucei, exosome secretion is induced by stress that affects trans-splicing. Following perturbations in biogenesis of spliced leader RNA, which donates its spliced leader (SL exon to all mRNAs, or after heat-shock, the SL RNA is exported to the cytoplasm and forms distinct granules, which are then secreted by exosomes. The exosomes are formed in multivesicular bodies (MVB utilizing the endosomal sorting complexes required for transport (ESCRT, through a mechanism similar to microRNA secretion in mammalian cells. Silencing of the ESCRT factor, Vps36, compromised exosome secretion but not the secretion of vesicles derived from nanotubes. The exosomes enter recipient trypanosome cells. Time-lapse microscopy demonstrated that cells secreting exosomes or purified intact exosomes affect social motility (SoMo. This study demonstrates that exosomes are delivered to trypanosome cells and can change their migration. Exosomes are used to transmit stress signals for communication between parasites.

  1. 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.

  2. Dynamin-like proteins in Trypanosoma brucei: A division of labour between two paralogs?

    Czech Academy of Sciences Publication Activity Database

    Benz, C.; Stříbrná, Eva; Hashimi, Hassan; Lukeš, Julius

    2017-01-01

    Roč. 12, č. 5 (2017), č. článku e0177200. E-ISSN 1932-6203 R&D Projects: GA ČR GA15-21974S; GA ČR GA17-24036S; GA MŠk LL1601 Institutional support: RVO:60077344 Keywords : blood-stream forms * mitochondrial fission * sequence alignment * gtpase activity * single dynamin * life-cycle * endocytosis * fis1 * expression * surface Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 2.806, year: 2016

  3. Characterization of Two Mitochondrial Flavin Adenine Dinucleotide-Dependent Glycerol-3-Phosphate Dehydrogenases in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Škodová, Ingrid; Verner, Zdeněk; Bringaud, F.; Fabian, P.; Lukeš, Julius; Horváth, A.

    2013-01-01

    Roč. 12, č. 12 (2013), s. 1664-1673 ISSN 1535-9778 R&D Projects: GA ČR(CZ) GAP305/11/2179; GA ČR GD206/09/H026; GA MŠk LH12104 Institutional support: RVO:60077344 Keywords : alternative NADH dehydrogenase * inducible expression system * blood-stream forms * complex-I * procyclic trypanosomes * sleeping sickness * oxidase * localization * metabolism * cycle Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.179, year: 2013

  4. 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

  5. Proteomics of Trypanosoma evansi infection in rodents.

    Science.gov (United States)

    Roy, Nainita; Nageshan, Rishi Kumar; Pallavi, Rani; Chakravarthy, Harshini; Chandran, Syama; Kumar, Rajender; Gupta, Ashok Kumar; Singh, Raj Kumar; Yadav, Suresh Chandra; Tatu, Utpal

    2010-03-22

    Trypanosoma evansi infections, commonly called 'surra', cause significant economic losses to livestock industry. While this infection is mainly restricted to large animals such as camels, donkeys and equines, recent reports indicate their ability to infect humans. There are no World Animal Health Organization (WAHO) prescribed diagnostic tests or vaccines available against this disease and the available drugs show significant toxicity. There is an urgent need to develop improved methods of diagnosis and control measures for this disease. Unlike its related human parasites T. brucei and T. cruzi whose genomes have been fully sequenced T. evansi genome sequence remains unavailable and very little efforts are being made to develop improved methods of prevention, diagnosis and treatment. With a view to identify potential diagnostic markers and drug targets we have studied the clinical proteome of T. evansi infection using mass spectrometry (MS). Using shot-gun proteomic approach involving nano-lc Quadrupole Time Of Flight (QTOF) mass spectrometry we have identified over 160 proteins expressed by T. evansi in mice infected with camel isolate. Homology driven searches for protein identification from MS/MS data led to most of the matches arising from related Trypanosoma species. Proteins identified belonged to various functional categories including metabolic enzymes; DNA metabolism; transcription; translation as well as cell-cell communication and signal transduction. TCA cycle enzymes were strikingly missing, possibly suggesting their low abundances. The clinical proteome revealed the presence of known and potential drug targets such as oligopeptidases, kinases, cysteine proteases and more. Previous proteomic studies on Trypanosomal infections, including human parasites T. brucei and T. cruzi, have been carried out from lab grown cultures. For T. evansi infection this is indeed the first ever proteomic study reported thus far. In addition to providing a glimpse into the

  6. Proteomics of Trypanosoma evansi infection in rodents.

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    Nainita Roy

    2010-03-01

    Full Text Available Trypanosoma evansi infections, commonly called 'surra', cause significant economic losses to livestock industry. While this infection is mainly restricted to large animals such as camels, donkeys and equines, recent reports indicate their ability to infect humans. There are no World Animal Health Organization (WAHO prescribed diagnostic tests or vaccines available against this disease and the available drugs show significant toxicity. There is an urgent need to develop improved methods of diagnosis and control measures for this disease. Unlike its related human parasites T. brucei and T. cruzi whose genomes have been fully sequenced T. evansi genome sequence remains unavailable and very little efforts are being made to develop improved methods of prevention, diagnosis and treatment. With a view to identify potential diagnostic markers and drug targets we have studied the clinical proteome of T. evansi infection using mass spectrometry (MS.Using shot-gun proteomic approach involving nano-lc Quadrupole Time Of Flight (QTOF mass spectrometry we have identified over 160 proteins expressed by T. evansi in mice infected with camel isolate. Homology driven searches for protein identification from MS/MS data led to most of the matches arising from related Trypanosoma species. Proteins identified belonged to various functional categories including metabolic enzymes; DNA metabolism; transcription; translation as well as cell-cell communication and signal transduction. TCA cycle enzymes were strikingly missing, possibly suggesting their low abundances. The clinical proteome revealed the presence of known and potential drug targets such as oligopeptidases, kinases, cysteine proteases and more.Previous proteomic studies on Trypanosomal infections, including human parasites T. brucei and T. cruzi, have been carried out from lab grown cultures. For T. evansi infection this is indeed the first ever proteomic study reported thus far. In addition to providing a

  7. Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae) and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil.

    Science.gov (United States)

    Leal, Denise D M; O'dwyer, Lucia H; Ribeiro, Vitor C; Silva, Reinaldo J; Ferreira, Vanda L; Rodrigues, Rozangela B

    2009-06-01

    Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads). The identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines and Trypanosoma spp. in anurans captured in the States of São Paulo andMato Grosso do Sul- Brazil and to perform the morphological and morphometric characterization of these hemoparasites. The species of anurans examined were: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusa hypocondrialis, Trachicephalus venulosus, Scinax fuscovarius and Hypsiboas albopunctatus. Of the total of 40 animals studied, four (10%)were positive for hemogregarines and eight (20%) were positive for Trypanosoma spp. Hemogregarine gamontsshowed variable morphology and, in addition to intraerythrocytic forms, extraerythrocytic forms were also observed.Extremely different forms of Trypanosoma were observed, as described in the literature, with the broad and oval forms being the most common.

  8. Trypanosoma brucei TBRGG1, a mitochondrial oligo(U)-binding protein that co-localizes with an in vitro RNA editing activity

    NARCIS (Netherlands)

    Vanhamme, L.; Perez-Morga, D.; Marchal, C.; Speijer, D.; Lambert, L.; Geuskens, M.; Alexandre, S.; Ismaïli, N.; Göringer, U.; Benne, R.; Pays, E.

    1998-01-01

    We report the characterization of a Trypanosoma brucei 75-kDa protein of the RGG (Arg-Gly-Gly) type, termed TBRGG1. Dicistronic and monocistronic transcripts of the TBRGG1 gene were produced by both alternative splicing and polyadenylation. TBRGG1 was found in two or three forms that differ in their

  9. 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.

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

    Science.gov (United States)

    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.

  11. Trypanosoma avium of raptors (Falconiformes): phylogeny and identification of vectors.

    Science.gov (United States)

    Votýpka, J; Oborník, M; Volf, P; Svobodová, M; Lukes, J

    2002-09-01

    Avian trypanosomes are widespread parasites of birds, the transmission of which remains mostly unclear, with various blood-sucking insects mentioned as possible vectors. A search for vectors of trypanosomes of sparrowhawk (Accipiter nisus), buzzard (Buteo buteo), lesser-spotted eagle (Aquila pomarina) and kestrel (Falco tinnunculus) was performed in Czech and Slovak Republics. Black flies (Eusimulium spp.), hippoboscid flies (Ornithomyia avicularia), mosquitoes (Culex pipiens pipiens) and biting midges (Culicoides spp.), trapped while attempting to feed on raptor nestlings, were found to contain trypanosomatids in their intestine. Trypanosomes from the raptors and blood-sucking insects were isolated, and their 18S rRNA sequences were used for species identification and for the inference of intra- and interspecific relationships. Together with the trypanosome isolated from a black fly, the bird trypanosomes formed a well-supported Trypanosoma avium clade. The isolates derived from hippoboscid flies and mosquitoes are most likely also avian trypanosomes infecting birds other than the studied raptors. Analysis of the kinetoplast, that has features characteristic for the avian trypanosomes (minicircle size; dimensions of the kinetoplast disc), provided further evidence for the identification of vectors. It is suggested that all trypanosomes isolated from raptors included in this study belong to the T. avium complex and are transmitted by the ornithophilic simuliids such as Eusimulium securiforme.

  12. 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.

  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. The activity of aminoglycoside antibiotics against Trypanosoma brucei.

    Science.gov (United States)

    Maina, N W; Kinyanjui, B; Onyango, J D; Auma, J E; Croj, S

    1998-01-01

    The trypanocidal activity of four aminoglycosides was determined against Trypanosoma brucei in vitro. The drug activity in descending order, was as follows; paromomycin kanamycin>gentamycin > neomycin. Paromomycin bad the highest activity and the concentration that inhibited 50% of trypanosome growth (IC50) was 11.4microM. The effect of paromomycin on the causative agents of the East African form of sleeping sickness - T.b. rhodesiense KETRI 265, 2285, 2545, 2562 and EATRO 110,112, 1152 was subsequently assessed. Variations sensitivities between the trypanosome populations were observed and IC50 values ranging from 13.01 to 43.06 microM recorded. However, when paromomycin was administered intraperitoneally (i.p) at 500 mg/kg, it was not effective in curing mice infected with T. b. rhodesienseKETRI 2545 the most drug-sensitive isolate in vitro. Lack of in vivo activity may be because the trypanosome is an extracellular parasite. The pharmacokinetics of paromomycin in the mouse model need to be determined.

  15. Active transcription and ultrastructural changes during Trypanosoma cruzi metacyclogenesis

    Directory of Open Access Journals (Sweden)

    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

  16. Evaluation of In Vitro Activity of Essential Oils against Trypanosoma brucei brucei and Trypanosoma evansi

    Directory of Open Access Journals (Sweden)

    Nathan Habila

    2010-01-01

    Full Text Available Essential oils (EOs from Cymbopogon citratus (CC, Eucalyptus citriodora (EC, Eucalyptus camaldulensis (ED, and Citrus sinensis (CS were obtained by hydrodistillation process. The EOs were evaluated in vitro for activity against Trypanosoma brucei brucei (Tbb and Trypanosoma evansi (T. evansi. The EOs were found to possess antitrypanosomal activity in vitro in a dose-dependent pattern in a short period of time. The drop in number of parasite over time was achieved doses of 0.4 g/ml, 0.2 g/mL, and 0.1 g/mL for all the EOs. The concentration of 0.4 g/mL CC was more potent at 3 minutes and 2 minutes for Tbb and T. evansi, respectively. The GC-MS analysis of the EOs revealed presence of Cyclobutane (96.09% in CS, 6-octenal (77.11% in EC, Eucalyptol (75% in ED, and Citral (38.32% in CC among several other organic compounds. The results are discussed in relation to trypanosome chemotherapy.

  17. Molecular diagnosis of cattle trypanosomes in Venezuela: evidences of Trypanosoma evansi and Trypanosoma vivax infections.

    Science.gov (United States)

    Ramírez-Iglesias, J R; Eleizalde, M C; Reyna-Bello, A; Mendoza, M

    2017-06-01

    In South America Trypanosoma evansi has been determined by molecular methods in cattle from Bolivia, Brazil, Colombia and Peru, reason for which the presence of this parasite is not excluded in Venezuelan livestock. Therefore, the aim of this study was to perform parasitological and molecular diagnosis of cattle trypanosomosis in small livestock units from two regions in this country. The parasitological diagnosis was carried out by MHCT and the molecular by PCR using genus-specific ITS1 primers that differentiate T. vivax and T. evansi infections. 47 cattle were evaluated in the "Laguneta de la Montaña" sector, Miranda State, where 3 animals were diagnosed as positive (6.4 %) by MHCT and 14 (30 %) by PCR as Trypanosoma spp., out of which 9 animals resulted positive for T. vivax , 3 for T. evansi and 2 with double infections. Whilst in the "San Casimiro" sector, State of Aragua, out of the 38 cattle evaluated 7 animals were diagnosed as positive (18.4 %) by MHCT and 19 (50 %) by PCR, determining only the presence of T. evansi in this locality. The molecular diagnosis by PCR using ITS1 primers allowed T. evansi detection in cattle field populations, which suggests the possible role of these animals as reservoirs in the epidemiology of the disease caused by T. evansi in Venezuela.

  18. Gastrointestinal parasites and Trypanosoma evansi in buffaloes

    International Nuclear Information System (INIS)

    Sani, R.A.; Chandrawathani, P.; Rosli, M.

    1990-01-01

    Gastrointestinal parasitism is common in buffalo calves. The effect of helminths on growth was studied by administration of an anthelmintic to buffalo calves following natural infections with gastrointestinal parasites. In studies conducted on calves belonging to an institute and a smallholder farmer, the treated calves showed improved weight gains. Serial parasitic examinations showed these animals had moderate to high faecal counts with Strongyloides, Toxocara vitulorum and Haemonchus eggs and Eimeria oocytes. In another study, there was no live weight advantage in treated over untreated calves. Few animals in this study had evidence of parasites and even those which were infested had low faecal egg counts. Hence, in general, helminths at certain levels of infection do affect the live weight gains of young buffalo calves. The prevalence of Trypanosoma evansi, as assessed parasitologically using the haematocrit centrifugation technique and mice inoculation, was 2.7 and 1%, respectively, in cattle and buffaloes. The serological prevalence using the enzyme linked immunosorbent assay was 35 and 2% for cattle and buffaloes, respectively. (author). 6 refs, 5 figs, 2 tabs

  19. Flagellar Motility of Trypanosoma cruzi Epimastigotes

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    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.

  20. Trypanosoma janseni n. sp. (Trypanosomatida: Trypanosomatidae isolated from Didelphis aurita (Mammalia: Didelphidae in the Atlantic Rainforest of Rio de Janeiro, Brazil: integrative taxonomy and phylogeography within the Trypanosoma cruzi clade

    Directory of Open Access Journals (Sweden)

    Camila Madeira Tavares Lopes

    Full Text Available BACKGROUND Didelphis spp. are a South American marsupial species that are among the most ancient hosts for the Trypanosoma spp. OBJECTIVES We characterise a new species (Trypanosoma janseni n. sp. isolated from the spleen and liver tissues of Didelphis aurita in the Atlantic Rainforest of Rio de Janeiro, Brazil. METHODS The parasites were isolated and a growth curve was performed in NNN and Schneider's media containing 10% foetal bovine serum. Parasite morphology was evaluated via light microscopy on Giemsa-stained culture smears, as well as scanning and transmission electron microscopy. Molecular taxonomy was based on a partial region (737-bp of the small subunit (18S ribosomal RNA gene and 708 bp of the nuclear marker, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH genes. Maximum likelihood and Bayesian inference methods were used to perform a species coalescent analysis and to generate individual and concatenated gene trees. Divergence times among species that belong to the T. cruzi clade were also inferred. FINDINGS In vitro growth curves demonstrated a very short log phase, achieving a maximum growth rate at day 3 followed by a sharp decline. Only epimastigote forms were observed under light and scanning microscopy. Transmission electron microscopy analysis showed structures typical to Trypanosoma spp., except one structure that presented as single-membraned, usually grouped in stacks of three or four. Phylogeography analyses confirmed the distinct species status of T. janseni n. sp. within the T. cruzi clade. Trypanosoma janseni n. sp. clusters with T. wauwau in a well-supported clade, which is exclusive and monophyletic. The separation of the South American T. wauwau + T. janseni coincides with the separation of the Southern Super Continent. CONCLUSIONS This clade is a sister group of the trypanosomes found in Australian marsupials and its discovery sheds light on the initial diversification process based on what we currently

  1. Trypanosoma janseni n. sp. (Trypanosomatida: Trypanosomatidae) isolated from Didelphis aurita (Mammalia: Didelphidae) in the Atlantic Rainforest of Rio de Janeiro, Brazil: integrative taxonomy and phylogeography within the Trypanosoma cruzi clade.

    Science.gov (United States)

    Lopes, Camila Madeira Tavares; Menna-Barreto, Rubem Figueiredo Sadok; Pavan, Márcio Galvão; Pereira, Mirian Cláudia De Souza; Roque, André Luiz R

    2018-01-01

    Didelphis spp. are a South American marsupial species that are among the most ancient hosts for the Trypanosoma spp. We characterise a new species (Trypanosoma janseni n. sp.) isolated from the spleen and liver tissues of Didelphis aurita in the Atlantic Rainforest of Rio de Janeiro, Brazil. The parasites were isolated and a growth curve was performed in NNN and Schneider's media containing 10% foetal bovine serum. Parasite morphology was evaluated via light microscopy on Giemsa-stained culture smears, as well as scanning and transmission electron microscopy. Molecular taxonomy was based on a partial region (737-bp) of the small subunit (18S) ribosomal RNA gene and 708 bp of the nuclear marker, glycosomal glyceraldehyde-3-phosphate dehydrogenase (gGAPDH) genes. Maximum likelihood and Bayesian inference methods were used to perform a species coalescent analysis and to generate individual and concatenated gene trees. Divergence times among species that belong to the T. cruzi clade were also inferred. In vitro growth curves demonstrated a very short log phase, achieving a maximum growth rate at day 3 followed by a sharp decline. Only epimastigote forms were observed under light and scanning microscopy. Transmission electron microscopy analysis showed structures typical to Trypanosoma spp., except one structure that presented as single-membraned, usually grouped in stacks of three or four. Phylogeography analyses confirmed the distinct species status of T. janseni n. sp. within the T. cruzi clade. Trypanosoma janseni n. sp. clusters with T. wauwau in a well-supported clade, which is exclusive and monophyletic. The separation of the South American T. wauwau + T. janseni coincides with the separation of the Southern Super Continent. This clade is a sister group of the trypanosomes found in Australian marsupials and its discovery sheds light on the initial diversification process based on what we currently know about the T. cruzi clade.

  2. First record of Trypanosoma chattoni in Brazil and occurrence of other Trypanosoma species in Brazilian frogs (Anura, Leptodactylidae).

    Science.gov (United States)

    Lemos, M; Morais, D H; Carvalho, V T; D'Agosto, M

    2008-02-01

    The present study provides the first record of Trypanosoma chattoni Mathis and Leger, 1911, in a new host, Leptodactylus fuscus Schneider, 1799 (Anura, Leptodactylidae), and the occurrence of Trypanosoma rotatorium-like species in Leptodactylus chaquensis Cei, 1950. The anurans were captured in the State of Mato Grosso, Brazil. Blood samples were obtained by cardiac puncture, and blood smears were examined for the presence of hemoparasites. The Trypanosoma rotatorium-like species in this study refers to a short-bodied trypomastigote that has a conspicuous undulating membrane but lacks a free flagellum; T. chattoni refers to a monomorphic parasite that has a rounded body, a kinetoplast adjacent to the nucleus, and a short flagellum.

  3. Acerca del ciclo evolutivo del Trypanosoma (Schizotrypanum cruzi Chagas 1909, en sus fases tisular y hematica

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    Cecilio Romaña

    1956-06-01

    Full Text Available El autor pasa en revista los trabajos publicados sobre el ciclo evolutivo del Trypanosoma (S. cruzi en el huésped vertebrado, desde el descubrimiento de la enfermedad hasta nuestros días. Luego analiza las ideas de los autores modernos, fundadas en gran parte en las observaciones que ya en 1914 realizaron MAYER y ROCHA LIMA de las cuales participan actualmente ROMAÑA y MEYER, ELKELES y WOOD. Finalmente expressa que a partir de los tripanosomas infectantes los parásitos que penetram en el protoplasma celular pueden seguir dos mecanismos en su evolución hacia cuerpos leishmanioides: 1.º Por "regresión fusiforme" y 2.º por "regresión orbicular"; llegados a la forma leishmanioide los parásitos se multiplican por división binaria, una vez lleno el protoplasma celular, siguen un processo inverso de transformación hacia tripanosoma que puede seguir igualmente dos mecanismos diversos: 1. "progresión fusiforme" y 2.º "progresión orbicular". Estos diversos mecanismos de transformación están esquematizados en la fig. N.º 1 del trabajo.The author reviews published works about the evolutive cycle of the Trypanosoma cruzi in the vertebrate host, from the discovery of the disease to our days. Then, he analyzes the ideas of the modern authors who based themselves on the observations made formerly, in 1914, by MAYER & ROCHA LIMA, ideas that ROMAÑA and MEYER, ELKELES and WOOD agree at the present time. Last, he states that, from the infective trypanosomas, the parasites which enter the cellular protoplasma may follow two systems to perform their evolution up to leishmanioid bodies: 1.] by fusiform regression, 2.º by an orbicular regression. Once the parasites reach the leishmanioid forms, they multiply by binary division. When the celular protoplasm is filled up with the parasites, these follow an inverted transformation up to trypanosoma state, following also two systems; similar to the repression 1.º a fusiform progression, 2.º an

  4. Variant surface glycoproteins from Venezuelan trypanosome isolates are recognized by sera from animals infected with either Trypanosoma evansi or Trypanosoma vivax.

    Science.gov (United States)

    Camargo, Rocío; Izquier, Adriana; Uzcanga, Graciela L; Perrone, Trina; Acosta-Serrano, Alvaro; Carrasquel, Liomary; Arias, Laura P; Escalona, José L; Cardozo, Vanessa; Bubis, José

    2015-01-15

    Salivarian trypanosomes sequentially express only one variant surface glycoprotein (VSG) on their cell surface from a large repertoire of VSG genes. Seven cryopreserved animal trypanosome isolates known as TeAp-ElFrio01, TEVA1 (or TeAp-N/D1), TeGu-N/D1, TeAp-Mantecal01, TeGu-TerecayTrino, TeGu-Terecay03 and TeGu-Terecay323, which had been isolated from different hosts identified in several geographical areas of Venezuela were expanded using adult albino rats. Soluble forms of predominant VSGs expressed during the early infection stages were purified and corresponded to concanavalin A-binding proteins with molecular masses of 48-67 kDa by sodium dodecyl sulfate-polyacrylamide gel electropohoresis, and pI values between 6.1 and 7.5. The biochemical characterization of all purified soluble VSGs revealed that they were dimers in their native form and represented different gene products. Sequencing of some of these proteins yielded peptides homologous to VSGs from Trypanosoma (Trypanozoon) brucei and Trypanosoma (Trypanozoon) evansi and established that they most likely are mosaics generated by homologous recombination. Western blot analysis showed that all purified VSGs were cross-reacting antigens that were recognized by sera from animals infected with either T. evansi or Trypanosoma (Dutonella) vivax. The VSG glycosyl-phosphatidylinositol cross-reacting determinant epitope was only partially responsible for the cross-reactivity of the purified proteins, and antibodies appeared to recognize cross-reacting conformational epitopes from the various soluble VSGs. ELISA experiments were performed using infected bovine sera collected from cattle in a Venezuelan trypanosome-endemic area. In particular, soluble VSGs from two trypanosome isolates, TeGu-N/D1 and TeGu-TeracayTrino, were recognized by 93.38% and 73.55% of naturally T. vivax-infected bovine sera, respectively. However, approximately 70% of the sera samples did not recognize all seven purified proteins. Hence, the

  5. 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.

  6. 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.

  7. 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...

  8. 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,

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. 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

  14. 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.

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

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    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.

  16. 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.

  17. [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.

  18. 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.

  19. 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.

  20. Trypanosoma cf. varani in an imported ball python (Python reginus) from Ghana.

    Science.gov (United States)

    Sato, Hiroshi; Takano, Ai; Kawabata, Hiroki; Une, Yumi; Watanabe, Haruo; Mukhtar, Maowia M

    2009-08-01

    Peripheral blood from a ball python (Python reginus) imported from Ghana was cultured in Barbour-Stoenner-Kelly (BSK) medium for Borrelia spp. isolation, resulting in the prominent appearance of free, and clusters of, trypanosomes in a variety of morphological forms. The molecular phylogenetic characterization of these cultured trypanosomes, using the small subunit rDNA, indicated that this python was infected with a species closely related to Trypanosoma varani Wenyon, 1908, originally described in the Nile monitor lizard (Varanus niloticus) from Sudan. Furthermore, nucleotide sequences of glycosomal glyceraldehyde-3-phosphate dehydrogenase gene of both isolates showed few differences. Giemsa-stained blood smears, prepared from the infected python 8 mo after the initial observation of trypanosomes in hemoculture, contained trypomastigotes with a broad body and a short, free flagellum; these most closely resembled the original description of T. varani, or T. voltariae Macfie, 1919 recorded in a black-necked spitting cobra (Naja nigricollis) from Ghana. It is highly possible that lizards and snakes could naturally share an identical trypanosome species. Alternatively, lizards and snakes in the same region might have closely related, but distinct, Trypanosoma species as a result of sympatric speciation. From multiple viewpoints, including molecular phylogenetic analyses, reappraisal of trypanosome species from a wide range of reptiles in Africa is needed to clarify the relationship of recorded species, or to unmask unrecorded species.

  1. A tropical tale: how Naja nigricollis venom beats Trypanosoma brucei

    DEFF Research Database (Denmark)

    Martos Esteban, Andrea; Laustsen, Andreas Hougaard; Carrington, Mark

    Trypanosoma brucei is a parasitic protozoan species capable to infecting insect vectors whose bite further produces African sleeping sickness inhuman beings [1]. During the parasite’s extracellular life in the mammalian host,its outer coat, mainly composed of Variable Surface Glycoproteins (VSGs)...

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

    Directory of Open Access Journals (Sweden)

    Humberto Menezes

    1981-06-01

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

  3. Role of sialic acids in the midguts of Trypanosoma congolense ...

    African Journals Online (AJOL)

    Administrator

    total sialic acid concentration. The relevance of these findings to the role of sialic acids in the midgut of. T. congolense infected C.p. pipiense mosquitoes is discussed in this paper. Key words: Trypanosoma congolense, Culex pipiense pipiense, sialic acid, midgut. INTRODUCTION. The Culex pipiense pipiense mosquito is ...

  4. Serum total protein, albumin and globulin levels in Trypanosoma ...

    African Journals Online (AJOL)

    The effect of orally administered Scoparia dulcis on Trypanosoma brucei-induced changes in serum total protein, albumin and globulin were investigated in rabbits over a period of twenty eight days. Results obtained show that infection resulted in hyperproteinaemia, hyperglobulinaemia and hypoalbuminaemia. However ...

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. 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

  13. A coagulase-negative and non-haemolytic strain of Staphylococcus aureus for investigating the roles of SrtA in a murine model of bloodstream infection.

    Science.gov (United States)

    Wang, Lin; Bi, Chongwei; Wang, Tiedong; Xiang, Hua; Chen, Fuguang; Hu, Jinping; Liu, Bingrun; Cai, Hongjun; Zhong, Xiaobo; Deng, Xuming; Wang, Dacheng

    2015-08-01

    Sortase A (SrtA) is a cysteine transpeptidase and virulence factor from Staphylococcus aureus (S. aureus) that catalyses the attachment and display of surface proteins on the cell wall, thereby mediating bacterial adhesion to host tissues, host-cell entry and evasion of the immune response. As a result, SrtA has become an important target in the development of therapies for S. aureus infections. In this study, we used the new reference strain S. aureus Newman D2C to investigate the role of SrtA in a murine model of bloodstream infection, when the impact of coagulase and haemolysin is excluded. The results suggested that deletion of SrtA reduced the bacterial burden on the heart, liver and kidneys by blunting the host proinflammatory cytokine response at an early point in infection. Kidneys, but not heart or liver, formed abscesses on the sixth day following non-lethal infection, and this effect was diminished by SrtA mutation. These findings indicate that SrtA is a determining virulence factor in lethality and formation of renal abscesses in mice followed by S. aureus bloodstream infection. We have thus established a convenient in vitro and mouse model for developing SrtA-targeted therapeutic strategies. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Comparative analysis of the kinomes of three pathogenic trypanosomatids: Leishmania major, Trypanosoma brucei and Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Ward Pauline N

    2005-09-01

    Full Text Available Abstract Background The trypanosomatids Leishmania major, Trypanosoma brucei and Trypanosoma cruzi cause some of the most debilitating diseases of humankind: cutaneous leishmaniasis, African sleeping sickness, and Chagas disease. These protozoa possess complex life cycles that involve development in mammalian and insect hosts, and a tightly coordinated cell cycle ensures propagation of the highly polarized cells. However, the ways in which the parasites respond to their environment and coordinate intracellular processes are poorly understood. As a part of an effort to understand parasite signaling functions, we report the results of a genome-wide analysis of protein kinases (PKs of these three trypanosomatids. Results Bioinformatic searches of the trypanosomatid genomes for eukaryotic PKs (ePKs and atypical PKs (aPKs revealed a total of 176 PKs in T. brucei, 190 in T. cruzi and 199 in L. major, most of which are orthologous across the three species. This is approximately 30% of the number in the human host and double that of the malaria parasite, Plasmodium falciparum. The representation of various groups of ePKs differs significantly as compared to humans: trypanosomatids lack receptor-linked tyrosine and tyrosine kinase-like kinases, although they do possess dual-specificity kinases. A relative expansion of the CMGC, STE and NEK groups has occurred. A large number of unique ePKs show no strong affinity to any known group. The trypanosomatids possess few ePKs with predicted transmembrane domains, suggesting that receptor ePKs are rare. Accessory Pfam domains, which are frequently present in human ePKs, are uncommon in trypanosomatid ePKs. Conclusion Trypanosomatids possess a large set of PKs, comprising approximately 2% of each genome, suggesting a key role for phosphorylation in parasite biology. Whilst it was possible to place most of the trypanosomatid ePKs into the seven established groups using bioinformatic analyses, it has not been

  19. 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

  20. 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.

  1. 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.

  2. 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

  3. Activity of D-carnitine and its derivatives on Trypanosoma infections in rats and mice

    Directory of Open Access Journals (Sweden)

    Manganaro M.

    2003-06-01

    Full Text Available Little progress has been made in the treatment of African trypanosomiasis over the past decades. L-carnitine has a major role in glycolysis-based energy supply of blood trypanosomes for it stimulates constant ATP production. To investigate whether administration of the isomer D-carnitine could exert a competitive inhibition on the metabolic pathway of the L-form, possibily resulting in parasite replication inhibition, several formulations of this compound were tested on Trypanosoma lewisi and T. brucei rhodesiense in rodent models. High oral dosages of D-carnitine inner salt and proprionyl-D-carnitine were not toxic to animals and induced about 50 % parasite growth inhibition in reversible, i.e. competitive, fashion. A putative mechanism could be an interference in pyruvate kinase activity and hence ATP production. Considering both, lack of toxicity and inhibitory activity, D-carnitine may have a role in the treatment of African trypanosomiasis, in association with available trypanocidal drugs.

  4. Meiosis and Haploid Gametes in the Pathogen Trypanosoma brucei

    OpenAIRE

    Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

    2014-01-01

    Summary In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence [1]. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector [2, 3] and involves meiosis [4], but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human...

  5. Trypanosoma brucei solanesyl-diphosphate synthase localizes to the mitochondrion

    Czech Academy of Sciences Publication Activity Database

    Lai, D.-H.; Bontempi, E. J.; Lukeš, Julius

    2012-01-01

    Roč. 183, č. 2 (2012), s. 189-192 ISSN 0166-6851 R&D Projects: GA ČR(CZ) GAP305/11/2179 Institutional support: RVO:60077344 Keywords : Trypanosoma brucei * Sleeping sickness * Ubiquinone * Solanesyl-diphosphate synthase * Digitonin permeabilization * In situ tagging Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.734, year: 2012 http://www.sciencedirect.com/science/article/pii/S0166685112000539

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Regulation and spatial organization of PCNA in Trypanosoma brucei

    International Nuclear Information System (INIS)

    Kaufmann, Doris; Gassen, Alwine; Maiser, Andreas; Leonhardt, Heinrich; Janzen, Christian J.

    2012-01-01

    Highlights: ► Characterization of the proliferating cell nuclear antigen in Trypanosoma brucei (TbPCNA). ► TbPCNA is a suitable marker to detect replication in T. brucei. ► TbPCNA distribution and regulation is different compared to closely related parasites T. cruzi and Leishmania donovani. -- Abstract: As in most eukaryotic cells, replication is regulated by a conserved group of proteins in the early-diverged parasite Trypanosoma brucei. Only a few components of the replication machinery have been described in this parasite and regulation, sub-nuclear localization and timing of replication are not well understood. We characterized the proliferating cell nuclear antigen in T. brucei (TbPCNA) to establish a spatial and temporal marker for replication. Interestingly, PCNA distribution and regulation is different compared to the closely related parasites Trypanosoma cruzi and Leishmania donovani. TbPCNA foci are clearly detectable during S phase of the cell cycle but in contrast to T. cruzi they are not preferentially located at the nuclear periphery. Furthermore, PCNA seems to be degraded when cells enter G2 phase in T. brucei suggesting different modes of replication regulation or functions of PCNA in these closely related eukaryotes.

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

    Science.gov (United States)

    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.

  9. Regulation and spatial organization of PCNA in Trypanosoma brucei

    Energy Technology Data Exchange (ETDEWEB)

    Kaufmann, Doris; Gassen, Alwine [University of Munich (LMU), Department Biology I, Genetics, Grosshaderner Str. 2-4, 82152 Martinsried (Germany); Maiser, Andreas; Leonhardt, Heinrich [University of Munich (LMU), Department Biology II, Grosshaderner Str. 2-4, 82152 Martinsried (Germany); Janzen, Christian J., E-mail: christian.janzen@uni-wuerzburg.de [University of Munich (LMU), Department Biology I, Genetics, Grosshaderner Str. 2-4, 82152 Martinsried (Germany)

    2012-03-23

    Highlights: Black-Right-Pointing-Pointer Characterization of the proliferating cell nuclear antigen in Trypanosoma brucei (TbPCNA). Black-Right-Pointing-Pointer TbPCNA is a suitable marker to detect replication in T. brucei. Black-Right-Pointing-Pointer TbPCNA distribution and regulation is different compared to closely related parasites T. cruzi and Leishmania donovani. -- Abstract: As in most eukaryotic cells, replication is regulated by a conserved group of proteins in the early-diverged parasite Trypanosoma brucei. Only a few components of the replication machinery have been described in this parasite and regulation, sub-nuclear localization and timing of replication are not well understood. We characterized the proliferating cell nuclear antigen in T. brucei (TbPCNA) to establish a spatial and temporal marker for replication. Interestingly, PCNA distribution and regulation is different compared to the closely related parasites Trypanosoma cruzi and Leishmania donovani. TbPCNA foci are clearly detectable during S phase of the cell cycle but in contrast to T. cruzi they are not preferentially located at the nuclear periphery. Furthermore, PCNA seems to be degraded when cells enter G2 phase in T. brucei suggesting different modes of replication regulation or functions of PCNA in these closely related eukaryotes.

  10. Rational Design of a New Trypanosoma rangeli Trans-Sialidase for Efficient Sialylation of Glycans

    DEFF Research Database (Denmark)

    Jers, Carsten; Michalak, Malwina; Larsen, Dorte Møller

    2014-01-01

    This paper reports rational engineering of Trypanosoma rangeli sialidase to develop an effective enzyme for a potentially important type of reactivity: production of sialylated prebiotic glycans. The Trypanosoma cruzi trans-sialidase and the homologous T. rangeli sialidase has previously been use...

  11. Melophagus ovinus and Trypanosoma (Megatrypanum) melophagium in ovines in the State of Minas Gerais, Brasil

    OpenAIRE

    Costa, José Oswaldo; Lima, Walter dos Santos; Leite, Antonio César Rios; Guimarães, Marcos Pezzi; Torres, Liléia Diotaiuti

    1983-01-01

    Neste trabalho Melophagus ovinus é identificado pela primeira vez no Estado de Minas Gerais e Trypanosoma (Megatrypanum) melophagium tem sua primeira ocorrência registrada no Brasil.Melophagus ovinus is identified for the first time in Minas Gerais State and Trypanosoma (Megatrypanum) melophagium in Brazil.

  12. Hemoparasites of the genus Trypanosoma (Kinetoplastida: Trypanosomatidae and hemogregarines in Anurans of the São Paulo and Mato Grosso do Sul States - Brazil

    Directory of Open Access Journals (Sweden)

    Denise D.M. Leal

    2009-06-01

    Full Text Available Wild animals are exposed to numerous pathogens, including hemoparasites. The Trypanosoma and hemogregarinegroup are frequently reported as parasites in anurans (frogs, tree frogs and toads. The identification of these hemoparasites is usually made through stage observation of their morphology in the peripheral blood of the host. There areno studies, however, based on the biological cycle of these hemoparasites. The objective of the present study was toevaluate the presence of hemogregarines and Trypanosoma spp. in anurans captured in the States of São Paulo andMato Grosso do Sul- Brazil and to perform the morphological and morphometric characterization of these hemoparasites. The species of anurans examined were: Dendropsophus nanus, D. minutus, Leptodactylus chaquensis L. podicipinus, L. labyrinthicus, L. fuscus, Bufo granulosus, B. schneideri, Phyllomedusa hypocondrialis, Trachicephalus venulosus, Scinax fuscovarius and Hypsiboas albopunctatus. Of the total of 40 animals studied, four (10%were positive for hemogregarines and eight (20% were positive for Trypanosoma spp. Hemogregarine gamontsshowed variable morphology and, in addition to intraerythrocytic forms, extraerythrocytic forms were also observed.Extremely different forms of Trypanosoma were observed, as described in the literature, with the broad and oval forms being the most common.Os animais silvestres estão expostos a inúmeros patógenos,dentre eles estão os hemoparasitas. Podem-se destacar espécies do gênero Trypanosoma e do grupo das hemogregarinas,que ocorrem com freqüência parasitando anuros (rãs, pererecas e sapos. Normalmente, a descrição destes hemoparasitas é feita através da morfologia dos estágios observados nosangue periférico do hospedeiro e as pesquisas sobre o ciclobiológico desses hemoparasitas são escassas. Os objetivos dopresente estudo foram avaliar a presença de hemogregarinas eTrypanosoma spp. em anuros capturados nos Estados de São Paulo e

  13. Trypanosoma brucei metabolite indolepyruvate decreases HIF-1α and glycolysis in macrophages as a mechanism of innate immune evasion.

    Science.gov (United States)

    McGettrick, Anne F; Corcoran, Sarah E; Barry, Paul J G; McFarland, Jennifer; Crès, Cécile; Curtis, Anne M; Franklin, Edward; Corr, Sinéad C; Mok, K Hun; Cummins, Eoin P; Taylor, Cormac T; O'Neill, Luke A J; Nolan, Derek P

    2016-11-29

    The parasite Trypanasoma brucei causes African trypanosomiasis, known as sleeping sickness in humans and nagana in domestic animals. These diseases are a major burden in the 36 sub-Saharan African countries where the tsetse fly vector is endemic. Untreated trypanosomiasis is fatal and the current treatments are stage-dependent and can be problematic during the meningoencephalitic stage, where no new therapies have been developed in recent years and the current drugs have a low therapeutic index. There is a need for more effective treatments and a better understanding of how these parasites evade the host immune response will help in this regard. The bloodstream form of T. brucei excretes significant amounts of aromatic ketoacids, including indolepyruvate, a transamination product of tryptophan. This study demonstrates that this process is essential in bloodstream forms, is mediated by a specialized isoform of cytoplasmic aminotransferase and, importantly, reveals an immunomodulatory role for indolepyruvate. Indolepyruvate prevents the LPS-induced glycolytic shift in macrophages. This effect is the result of an increase in the hydroxylation and degradation of the transcription factor hypoxia-inducible factor-1α (HIF-1α). The reduction in HIF-1α levels by indolepyruvate, following LPS or trypanosome activation, results in a decrease in production of the proinflammatory cytokine IL-1β. These data demonstrate an important role for indolepyruvate in immune evasion by T. brucei.

  14. 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.

  15. 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

  16. Estudios sobre Trypanosoma rangeli Tejera, 1920: VIII. Respuesta a las reinfecciones en dos mamíferos Trypanosoma rangeli Tejera, 1920: VIII. Responses to reinfections in 2 mammals

    Directory of Open Access Journals (Sweden)

    N. Añez

    1985-06-01

    Full Text Available Bajo condiciones experimentales se estudia el curso de la infección primaria y la respuesta a las reinfecciones por Trypanosoma rangeli en ratones albinos y Didelphis marsupialis. Durante el curso de la infección primaria en ratones, se observa una parasitemia relativamente baja y de corta duración. Los mismos muestran durante la primera reinfección una parasitemia escasa de cuatro días de duración, siendo resistentes a las sucesivas reinfecciones con T. rangeli. Los ejemplares de D. marsupialis exhiben una parasitemia de más larga duración, pero con un nivel de parásitos sanguícolas mucho menor que el detectado en el modelo ratón, siendo la respuesta a las reinfecciones similar a la observada en ratones. Se detectan anticuerpos hemaglutinantes en los sueros inmunes de ratones y Didelphis marsupialis, sometidos a la reinfección por T. rangeli. Se especula sobre la posible acción sinérgica de una respuesta inmune en el sitio de deposición en contra de las formas metacíclicas de T. rangeli y la acción de anticuerpos circulantes en contra de las formas sanguícolas, para explicar la resistencia de ambos modelos a las reinfecciones por T. rangeli.Under experimental conditions, the course of the infection and the response to the reinfection by Trypanosoma rangeli in mice and Didelphis marsupialis, are studied. During the initial infection the mice show a relatively low parasitaemia and a short patent period. A scanty parasitaemia level of four days length, was observed following the first reinfection, being the mice resistant to new reinfections by T. rangeli. In opossums a lower parasitaemia and a longer patent period than that detected in mice, were observed during the initial infection. The response to reinfections in this mammal, was similar to that observed in mice. After reinfection with T. rangeli, haemagglutinant antibodies in immune-sera of both mice and opossums, were detected. The possible immune-response at the site of

  17. 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.

  18. 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

  19. 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)

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. 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...

  3. 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.

  4. 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.

  5. 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...

  6. [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.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  9. A role for Sar1 and ARF1 GTPases during Golgi biogenesis in the protozoan parasite Trypanosoma brucei

    Science.gov (United States)

    Yavuz, Sevil; Warren, Graham

    2017-01-01

    A single Golgi stack is duplicated and partitioned into two daughter cells during the cell cycle of the protozoan parasite Trypanosoma brucei. The source of components required to generate the new Golgi and the mechanism by which it forms are poorly understood. Using photoactivatable GFP, we show that the existing Golgi supplies components directly to the newly forming Golgi in both intact and semipermeabilized cells. The movement of a putative glycosyltransferase, GntB, requires the Sar1 and ARF1 GTPases in intact cells. In addition, we show that transfer of GntB from the existing Golgi to the new Golgi can be recapitulated in semipermeabilized cells and is sensitive to the GTP analogue GTPγS. We suggest that the existing Golgi is a key source of components required to form the new Golgi and that this process is regulated by small GTPases. PMID:28495798

  10. Morphological and molecular characterization and phylogenetic relationships of a new species of trypanosome in Tapirus terrestris (lowland tapir), Trypanosoma terrestris sp. nov., from Atlantic Rainforest of southeastern Brazi.

    Science.gov (United States)

    Acosta, Igor da Cunha Lima; da Costa, Andrea Pereira; Nunes, Pablo Henrique; Gondim, Maria Fernanda Naegeli; Gatti, Andressa; Rossi, João Luiz; Gennari, Solange Maria; Marcili, Arlei

    2013-12-11

    The Lowland tapir (Tapirus terrestris) is the largest Brazilian mammal and despite being distributed in various Brazilian biomes, it is seriously endangered in the Atlantic Rainforest. These hosts were never evaluated for the presence of Trypanosoma parasites. The Lowland tapirs were captured in the Brazilian southeastern Atlantic Rainforest, Espírito Santo state. Trypanosomes were isolated by hemoculture, and the molecular phylogeny based on small subunit rDNA (SSU rDNA) and glycosomal-3-phosphate dehydrogenase (gGAPDH) gene sequences and the ultrastructural features seen via light microscopy and scanning and transmission electron microscopy are described. Phylogenetic trees using combined SSU rDNA and gGAPDH data sets clustered the trypanosomes of Lowland tapirs, which were highly divergent from other trypanosome species. The phylogenetic position and morphological discontinuities, mainly in epimastigote culture forms, made it possible to classify the trypanosomes from Lowland tapirs as a separate species. The isolated trypanosomes from Tapirus terrestris are a new species, Trypanosoma terrestris sp. n., and were positioned in a new Trypanosoma clade, named T. terrestris clade.

  11. Trypanosoma sp. diversity in Amazonian bats (Chiroptera; Mammalia) from Acre State, Brazil.

    Science.gov (United States)

    Dos Santos, Francisco C B; Lisboa, Cristiane V; Xavier, Samanta C C; Dario, Maria A; Verde, Rair de S; Calouro, Armando M; Roque, André Luiz R; Jansen, Ana M

    2017-11-16

    Bats are ancient hosts of Trypanosoma species and their flying ability, longevity and adaptability to distinct environments indicate that they are efficient dispersers of parasites. Bats from Acre state (Amazon Biome) were collected in four expeditions conducted in an urban forest (Parque Zoobotânico) and one relatively more preserved area (Seringal Cahoeira) in Rio Branco and Xapuri municipalities. Trypanosoma sp. infection was detected by hemoculture and fresh blood examination. Isolated parasite species were identified by the similarity of the obtained DNA sequence from 18S rDNA polymerase chain reaction and reference strains. Overall, 367 bats from 23 genera and 32 species were examined. Chiropterofauna composition was specific to each municipality, although Artibeus sp. and Carollia sp. prevailed throughout. Trypanosoma sp. infection was detected in 85 bats (23·2%). The most widely distributed and prevalent genotypes were (in order) Trypanosoma cruzi TcI, T. cruzi marinkellei, Trypanosoma dionisii, T. cruzi TcIV and Trypanosoma rangeli. At least one still-undescribed Trypanosoma species was also detected in this study. The detection of T. cruzi TcI and TcIV (the ones associated with Chagas disease in Amazon biome) demonstrates the putative importance of these mammal hosts in the epidemiology of the disease in the Acre State.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. 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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    International Nuclear Information System (INIS)

    Hashimoto, Muneaki; Morales, Jorge; Fukai, Yoshihisa; Suzuki, Shigeo; Takamiya, Shinzaburo; Tsubouchi, Akiko; Inoue, Syou; Inoue, Masayuki; Kita, Kiyoshi; Harada, Shigeharu; Tanaka, Akiko; Aoki, Takashi; Nara, Takeshi

    2012-01-01

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

  18. Internalization of components of the host cell plasma membrane during infection by Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Whole-Genome-Sequencing characterization of bloodstream infection-causing hypervirulent Klebsiella pneumoniae of capsular serotype K2 and ST374.

    Science.gov (United States)

    Wang, Xiaoli; Xie, Yingzhou; Li, Gang; Liu, Jialin; Li, Xiaobin; Tian, Lijun; Sun, Jingyong; Ou, Hong-Yu; Qu, Hongping

    2018-01-01

    Hypervirulent K. pneumoniae variants (hvKP) have been increasingly reported worldwide, causing metastasis of severe infections such as liver abscesses and bacteremia. The capsular serotype K2 hvKP strains show diverse multi-locus sequence types (MLSTs), but with limited genetics and virulence information. In this study, we report a hypermucoviscous K. pneumoniae strain, RJF293, isolated from a human bloodstream sample in a Chinese hospital. It caused a metastatic infection and fatal septic shock in a critical patient. The microbiological features and genetic background were investigated with multiple approaches. The Strain RJF293 was determined to be multilocis sequence type (ST) 374 and serotype K2, displayed a median lethal dose (LD50) of 1.5 × 10 2 CFU in BALB/c mice and was as virulent as the ST23 K1 serotype hvKP strain NTUH-K2044 in a mouse lethality assay. Whole genome sequencing revealed that the RJF293 genome codes for 32 putative virulence factors and exhibits a unique presence/absence pattern in comparison to the other 105 completely sequenced K. pneumoniae genomes. Whole genome SNP-based phylogenetic analysis revealed that strain RJF293 formed a single clade, distant from those containing either ST66 or ST86 hvKP. Compared to the other sequenced hvKP chromosomes, RJF293 contains several strain-variable regions, including one prophage, one ICEKp1 family integrative and conjugative element and six large genomic islands. The sequencing of the first complete genome of an ST374 K2 hvKP clinical strain should reinforce our understanding of the epidemiology and virulence mechanisms of this bloodstream infection-causing hvKP with clinical significance.

  1. 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.

  2. 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.

  3. 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.

  4. 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...

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

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    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.

  6. 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...

  7. Novel molecular mechanism for targeting the parasite Trypanosoma brucei with snake venom toxins

    DEFF Research Database (Denmark)

    Martos Esteban, Andrea; Laustsen, Andreas Hougaard; Carrington, Mark

    Trypanosoma brucei is a parasitic protozoan species capable to infecting insect vectors whose bite further produces African sleeping sickness inhuman beings. During parasites’extracellular lives in the mammalian host, its outer coat, mainly composedof Variable surface glycoproteins (VSGs)[2...

  8. Persistent ER stress induces the spliced leader RNA silencing pathway (SLS, leading to programmed cell death in Trypanosoma brucei.

    Directory of Open Access Journals (Sweden)

    Hanoch Goldshmidt

    2010-01-01

    Full Text Available Trypanosomes are parasites that cycle between the insect host (procyclic form and mammalian host (bloodstream form. These parasites lack conventional transcription regulation, including factors that induce the unfolded protein response (UPR. However, they possess a stress response mechanism, the spliced leader RNA silencing (SLS pathway. SLS elicits shut-off of spliced leader RNA (SL RNA transcription by perturbing the binding of the transcription factor tSNAP42 to its cognate promoter, thus eliminating trans-splicing of all mRNAs. Induction of endoplasmic reticulum (ER stress in procyclic trypanosomes elicits changes in the transcriptome similar to those induced by conventional UPR found in other eukaryotes. The mechanism of up-regulation under ER stress is dependent on differential stabilization of mRNAs. The transcriptome changes are accompanied by ER dilation and elevation in the ER chaperone, BiP. Prolonged ER stress induces SLS pathway. RNAi silencing of SEC63, a factor that participates in protein translocation across the ER membrane, or SEC61, the translocation channel, also induces SLS. Silencing of these genes or prolonged ER stress led to programmed cell death (PCD, evident by exposure of phosphatidyl serine, DNA laddering, increase in reactive oxygen species (ROS production, increase in cytoplasmic Ca(2+, and decrease in mitochondrial membrane potential, as well as typical morphological changes observed by transmission electron microscopy (TEM. ER stress response is also induced in the bloodstream form and if the stress persists it leads to SLS. We propose that prolonged ER stress induces SLS, which serves as a unique death pathway, replacing the conventional caspase-mediated PCD observed in higher eukaryotes.

  9. 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.

  10. 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

  11. Trypanosoma (Megatrypanum saloboense n. sp. (Kinetoplastida: Trypanosomatidae parasite of Monodelphis emiliae (Marsupiala: Didelphidae from Amazonian Brazil

    Directory of Open Access Journals (Sweden)

    Lainson R.

    2008-06-01

    Full Text Available Trypanosoma (Megatrypanum saloboense n. sp., is described in the Brazilian opossum Monodelphis emiliae (Thomas, 1912 from primary forest in the Salobo area of the Serra dos Carajás (6° S, 50° 18′ W Pará State, North Brazil. Two morphologically different trypomastigotes were noted. Slender forms, regarded as immature parasites, have a poorly developed undulating membrane adhering closely to the body: large, broad forms with a well developed membrane are considered to be the mature trypomastigotes and have a mean total length of 71.2 μm (62.4-76.2 and a width of 6.1 (5.0-8.0. Infections studied in two opossums were of very low parasitaemia. The large size of T. (M. saloboense readily distinguishes it from the two previously described members of the subgenus Megatrypanum of neotropical marsupials, T. (M. freitasi Régo et al., 1957 of Didelphis azarae and D. marsupialis, and T. (M. samueli Mello, 1977 of Monodelphis domesticus, which measure only 49.0-51.5 μm and 42.4 μm respectively. No infections were obtained in hamsters inoculated with triturated liver and spleen from one infected M. emiliae, or in laboratory mice inoculated with epimastigotes from a blood-agar culture. No division stages could be detected in the internal organs or the peripheral blood.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. 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.

  14. 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)

  15. 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.

  16. [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.

  17. 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

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

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    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.

  19. 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.

  20. 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

  1. Teaching Form as Form

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2012-01-01

    understanding of form per se, or, to use an expression from this text, of form as form. This challenge can be reduced to one question: how can design teaching support students in achieving not only the ability to recognize and describe different form-related concepts in existing design (i.e. analytical...

  2. Mosaic VSGs and the scale of Trypanosoma brucei antigenic variation.

    Directory of Open Access Journals (Sweden)

    James P J Hall

    Full Text Available A main determinant of prolonged Trypanosoma brucei infection and transmission and success of the parasite is the interplay between host acquired immunity and antigenic variation of the parasite variant surface glycoprotein (VSG coat. About 0.1% of trypanosome divisions produce a switch to a different VSG through differential expression of an archive of hundreds of silent VSG genes and pseudogenes, but the patterns and extent of the trypanosome diversity phenotype, particularly in chronic infection, are unclear. We applied longitudinal VSG cDNA sequencing to estimate variant richness and test whether pseudogenes contribute to antigenic variation. We show that individual growth peaks can contain at least 15 distinct variants, are estimated computationally to comprise many more, and that antigenically distinct 'mosaic' VSGs arise from segmental gene conversion between donor VSG genes or pseudogenes. The potential for trypanosome antigenic variation is probably much greater than VSG archive size; mosaic VSGs are core to antigenic variation and chronic infection.

  3. 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

  4. Electron Microscopy Analysis of the Nucleolus of Trypanosoma cruzi

    Science.gov (United States)

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

    2005-08-01

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

  5. 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

  6. First report of Trypanosoma vegrandis in koalas (Phascolarctos cinereus).

    Science.gov (United States)

    Barbosa, Amanda; Austen, Jill; Gillett, Amber; Warren, Kristin; Paparini, Andrea; Irwin, Peter; Ryan, Una

    2016-08-01

    The present study describes the first report of Trypanosoma vegrandis in koalas using morphology and sequence analysis of the 18S rRNA gene. The prevalence of T. vegrandis in koalas was 13.6% (6/44). It is likely that the small size of T. vegrandis (<10μm in length), coupled with the difficulties in amplifying DNA of this parasite in mixed infections using trypanosome generic primers, are the reason why this organism has not been identified in koalas until now. This study highlights the importance of further research comprising a larger sample size to determine the prevalence of T. vegrandis in koalas as well as its potential impacts upon this marsupial species' health. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. The orthologue of Sjögren's syndrome nuclear autoantigen 1 (SSNA1 in Trypanosoma brucei is an immunogenic self-assembling molecule.

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    Helen P Price

    Full Text Available Primary Sjögren's Syndrome (PSS is a highly prevalent autoimmune disease, typically manifesting as lymphocytic infiltration of the exocrine glands leading to chronically impaired lacrimal and salivary secretion. Sjögren's Syndrome nuclear autoantigen 1 (SSNA1 or NA14 is a major specific target for autoantibodies in PSS but the precise function and clinical relevance of this protein are largely unknown. Orthologues of the gene are absent from many of the commonly used model organisms but are present in Chlamyodomonas reinhardtii (in which it has been termed DIP13 and most protozoa. We report the functional characterisation of the orthologue of SSNA1 in the kinetoplastid parasite, Trypanosoma brucei. Both TbDIP13 and human SSNA1 are small coiled-coil proteins which are predicted to be remote homologues of the actin-binding protein tropomyosin. We use comparative proteomic methods to identify potential interacting partners of TbDIP13. We also show evidence that TbDIP13 is able to self-assemble into fibril-like structures both in vitro and in vivo, a property which may contribute to its immunogenicity. Endogenous TbDIP13 partially co-localises with acetylated α-tubulin in the insect procyclic stage of the parasite. However, deletion of the DIP13 gene in cultured bloodstream and procyclic stages of T. brucei has little effect on parasite growth or morphology, indicating either a degree of functional redundancy or a function in an alternative stage of the parasite life cycle.

  8. 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

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

    Directory of Open Access Journals (Sweden)

    Patrícia Shima Luize

    2005-03-01

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

  10. 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.

  11. 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.

  12. 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.

  13. Comparative study of different methods used to isolate Trypanosoma cruz i for defibrinated blood of irradiated mice

    International Nuclear Information System (INIS)

    Fontes, G.; Romanha, A.J.; Brener, Z.

    1991-01-01

    Different methods are being used for the isolation and purification of Trypanosoma cruzi blood forms from infected vertebrate hosts. In this study, we compare four of these methods (differential centrifugation, Ficoll-Hypaque, Histopaque 1077 and metrizamide) in terms of parasite recovery rates, contamination with cells, duration of the process and role of host irradiation. Male albino Swiss mice irradiated in a Gamma Cell 220(500 rads) were inoculated with C L and V-10 T.cruzi strains and bled at the peak of parasitemia. Infected defibrinated blood was then used for the isolation. Although all methods permitted the recovery of viable trypomastigotes, the best results were obtained with Ficoll-Hypaque and Histopaque 1077. Recovery rates ranged between 71% to 88% and parasite-enriched preparations were obtained in approximately 75 min. Irradiation and blood defibrination drastically reduced platelet and leukocyte contamination of the preparations. (author)

  14. Processing of metacaspase 2 from Trypanosoma brucei (TbMCA2) broadens its substrate specificity.

    Science.gov (United States)

    Gilio, Joyce M; Marcondes, Marcelo F; Ferrari, Débora; Juliano, Maria A; Juliano, Luiz; Oliveira, Vitor; Machado, Maurício F M

    2017-04-01

    Metacaspases are members of the cysteine peptidase family and may be implicated in programmed cell death in plants and lower eukaryotes. These proteases exhibit calcium-dependent activity and specificity for arginine residues at P 1 . In contrast to caspases, they do not require processing or dimerization for activity. Indeed, unprocessed metacaspase-2 of Trypanosoma brucei (TbMCA2) is active; however, it has been shown that cleavages at Lys 55 and Lys 268 increase TbMCA2 hydrolytic activity on synthetic substrates. The processed TbMCA2 comprises 3 polypeptide chains that remain attached by non-covalent bonds. Replacement of Lys 55 and Lys 268 with Gly via site-directed mutagenesis results in non-processed but enzymatically active mutant, TbMCA2 K55/268G. To investigate the importance of this processing for the activity and specificity of TbMCA2, we performed activity assays comparing the non-processed mutant (TbMCA2 K55/268G) with the processed TbMCA2 form. Significant differences between TbMCA2 WT (processed form) and TbMCA2 K55/268G (non-processed form) were observed. Specifically, we verified that although non-processed TbMCA2 is active when assayed with small synthetic substrates, the TbMCA2 form does not exhibit hydrolytic activity on large substrates such as azocasein, while processed TbMCA2 is able to readily digest this protein. Such differences can be relevant for understanding the physiological regulation and function of TbMCA2. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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.

  17. 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.

  18. Design of Trypanosoma rangeli sialidase mutants with improved trans-sialidase activity.

    Directory of Open Access Journals (Sweden)

    Christian Nyffenegger

    Full Text Available A sialidase (EC 3.2.1.18 from the non-pathogenic Trypanosoma rangeli, TrSA, has been shown to exert trans-sialidase activity after mutation of five specific amino acids in the active site (M96V, A98P, S120Y, G249Y, Q284P to form the so-called TrSA5mut enzyme. By computational and hypothesis driven approaches additional mutations enhancing the trans-sialidase activity have been suggested. In the present work, we made a systematic combination of these mutations leading to seven new variants of the T. rangeli sialidase, having 6-16 targeted amino acid mutations. The resulting enzyme variants were analyzed via kinetics for their ability to carry out trans-sialidase reaction using CGMP and D-lactose as substrates. The sialidase variants with 15 and 16 mutations, respectively, exhibited significantly improved trans-sialidase activity for D-lactose sialylation. Our results corroborate, that computational studies of trans-glycosylation can be a valuable input in the design of novel trans-glycosidases, but also highlight the importance of experimental validation in order to assess the performance. In conclusion, two of the seven mutants displayed a dramatic switch in specificity from hydrolysis towards trans-sialylation and constitute the most potent trans-sialidase mutants of TrSA described in literature to date.

  19. 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.

  20. Trypanosoma (Herpetosoma rangeli Tejera, 1920: intracellular amastigote stages of reproduction in white mice

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    Servio Urdaneta-Morales

    1986-06-01

    Full Text Available The method, site, and stage of multiplication of Trypanosoma (Herpetosoma rangeli Tejera, 1920 has not hitherto been known. "We have now observed many intracellular nests or pseudocysts, containing amastigotes and trypomastigotes of this parasite in the heart, liver, and spleen of suckling (5.0 g male white mice (NMRI strain inoculated i.p. with 9 x 10(4 metatrypomastigotes/g body weight from a 12-day-old culture of the "Dog-82" strain of T. rangeli. At the peak of parasitemia (1.9 x 10(6 trypomastigotes/ml blood, 3 days post-inoculation various tissues were taken for sectioning and staining. The heart was most intensely parasitized. The amastigotes were rounded or ellipsoidal, with a rounded nucleus and the kinetoplast in the form of a straight or curved bar; the average maximum diameter of 50 measured amastigotes was 4.2 p. Binary fission was seen in the nucleus and kinetoplast of some amastigotes; no blood trypomastigotes were seen in division. The above characteristics, as well as the location of the pseudocysts in the tissues, are similar to T. cruzi. Comparison of these results with those reported for other Herpetosoma suggest study of the taxonomic position of T. rangeli.

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

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    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.

  2. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    International Nuclear Information System (INIS)

    Souza, C.F.; Carneiro, A.B.; Silveira, A.B.; Laranja, G.A.T.; Silva-Neto, M.A.C.; Costa, S.C. Goncalves da; Paes, M.C.

    2009-01-01

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

  3. Interactions among Trypanosoma brucei RAD51 paralogues in DNA repair and antigenic variation

    Science.gov (United States)

    Dobson, Rachel; Stockdale, Christopher; Lapsley, Craig; Wilkes, Jonathan; McCulloch, Richard

    2011-01-01

    Homologous recombination in Trypanosoma brucei is used for moving variant surface glycoprotein (VSG) genes into expression sites during immune evasion by antigenic variation. A major route for such VSG switching is gene conversion reactions in which RAD51, a universally conserved recombinase, catalyses homology-directed strand exchange. In any eukaryote, RAD51-directed strand exchange in vivo is mediated by further factors, including RAD51-related proteins termed Rad51 paralogues. These appear to be ubiquitously conserved, although their detailed roles in recombination remain unclear. In T. brucei, four putative RAD51 paralogue genes have been identified by sequence homology. Here we show that all four RAD51 paralogues act in DNA repair, recombination and RAD51 subnuclear dynamics, though not equivalently, while mutation of only one RAD51 paralogue gene significantly impedes VSG switching. We also show that the T. brucei RAD51 paralogues interact, and that the complexes they form may explain the distinct phenotypes of the mutants as well as observed expression interdependency. Finally, we document the Rad51 paralogues that are encoded by a wide range of protists, demonstrating that the Rad51 paralogue repertoire in T. brucei is unusually large among microbial eukaryotes and that one member of the protein family corresponds with a key, conserved eukaryotic Rad51 paralogue. PMID:21615552

  4. Histopathological study of experimental and natural infections by Trypanosoma cruzi in Didelphis marsupialis

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    João Carlos Araujo Carreira

    1996-10-01

    Full Text Available Didelphis marsupialis, the most important sylvatic reservoir of Trypanosoma cruzi, can also maintain in their anal scent glands the multiplicative forms only described in the intestinal tract of triatomine bugs. A study of 21 experimentally and 10 naturally infected opossums with T. cruzi was undertaken in order to establish the histopathological pattern under different conditions. Our results showed that the inflammation was predominantly lymphomacrophagic and more severe in the naturally infected animals but never as intense as those described in Chagas' disease or in other animal models. The parasitism in both groups was always mild with very scarce amastigote nests in the tissues. In the experimentally infected animals, the inflammation was directly related to the presence of amastigotes nests. Four 24 days-old animals, still in embryonic stage, showed multiple amastigotes nests and moderate inflammatory reactions, but even so they survived longer and presented less severe lesions than experimentally infected adult mice. Parasites were found in smooth, cardiac and/or predominantly striated muscles, as well as in nerve cells. Differing from the experimentally infected opossums parasitism in the naturally infected animals predominated in the heart, esophagus and stomach. Parasitism of the scent glands did not affect the histopathological pattern observed in extraglandular tissues.

  5. Heme-induced Trypanosoma cruzi proliferation is mediated by CaM kinase II

    Energy Technology Data Exchange (ETDEWEB)

    Souza, C.F. [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Carneiro, A.B.; Silveira, A.B. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); Laranja, G.A.T. [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); Silva-Neto, M.A.C. [Laboratorio de Sinalizacao Celular, Instituto de Bioquimica Medica, UFRJ (Brazil); INCT, Entomologia Molecular (Brazil); Costa, S.C. Goncalves da [Laboratorio de Imunomodulacao e Protozoologia, Instituto Oswaldo Cruz, Fiocruz (Brazil); Paes, M.C., E-mail: mcpaes@uerj.br [Laboratorio de Interacao Tripanosomatideos e Vetores, Departamento de Bioquimica, IBRAG, UERJ, 20551-030 Rio de Janeiro (Brazil); INCT, Entomologia Molecular (Brazil)

    2009-12-18

    Trypanosoma cruzi, the etiologic agent of Chagas disease, is transmitted through triatomine vectors during their blood-meal on vertebrate hosts. These hematophagous insects usually ingest approximately 10 mM of heme bound to hemoglobin in a single meal. Blood forms of the parasite are transformed into epimastigotes in the crop which initiates a few hours after parasite ingestion. In a previous work, we investigated the role of heme in parasite cell proliferation and showed that the addition of heme significantly increased parasite proliferation in a dose-dependent manner . To investigate whether the heme effect is mediated by protein kinase signalling pathways, parasite proliferation was evaluated in the presence of several protein kinase (PK) inhibitors. We found that only KN-93, a classical inhibitor of calcium-calmodulin-dependent kinases (CaMKs), blocked heme-induced cell proliferation. KN-92, an inactive analogue of KN-93, was not able to block this effect. A T. cruzi CaMKII homologue is most likely the main enzyme involved in this process since parasite proliferation was also blocked when Myr-AIP, an inhibitory peptide for mammalian CaMKII, was included in the cell proliferation assay. Moreover, CaMK activity increased in parasite cells with the addition of heme as shown by immunological and biochemical assays. In conclusion, the present results are the first strong indications that CaMKII is involved in the heme-induced cell signalling pathway that mediates parasite proliferation.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Equipe interdisciplinar reduz infecção sanguínea relacionada ao cateter venoso central em Unidade de Terapia Intensiva Pediátrica Interdisciplinary task-force reduces catheter-related bloodstream infection in a Pediatric Intensive Care Unit

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    Ricardo Vilela

    2010-12-01

    Full Text Available OBJETIVO: Avaliar o impacto de intervenções interdisciplinares nos indicadores de infecção de corrente sanguínea relacionada ao cateter venoso central e microrganismos isolados, em uma Unidade de Terapia Intensiva Pediátrica. MÉTODOS: Estudo de intervenção do tipo antes e depois. Foi criado um programa educativo e constituída uma equipe interdisciplinar de intervenção composta por médicos e enfermeiros da unidade e do Serviço de Controle de Infecção Hospitalar. As intervenções foram compostas por medidas diretas e indiretas educativas e processuais. O período pré-intervenção (Fase 1, de junho de 2003 a maio de 2004, foi comparado ao período pós-intervenção nas Fases 2 (junho de 2004 a maio de 2005 e 3 (junho de 2005 a maio de 2006. As taxas de infecção foram comparadas por ANOVA, sendo significante pOBJECTIVE: To determine the impact of interdisciplinary interventions on central venous catheter-related bloodstream infections rates in a Pediatric Intensive Care Unit (PICU and on the bloodstream infection organisms. METHODS: Interventional study type before-and-after. An educational program was performed and an interdisciplinary team of interventions was created. This team was formed by nurses and doctors of the PICU and of the Infection Control Committee. The interventions were composed by direct and indirect educational and procedural measures. Task-force interventions were developed from Jun/2003 to May/2004. This pre-intervention period (Phase 1 was compared with two post-intervention periods: Phases 2 (Jun/2004 to May/2005 and 3 (Jun/2005 to May/2006. Central venous catheter-related bloodstream infection rates during the three periods were compared by ANOVA, being significant p<0.05. RESULTS: 1,234 patients were studied from June 1st 2003 to May 31, 2006. The number of central venous catheter-related bloodstream infections was 22.72 per 1,000 catheter-days in Phase 1, and 6.81 and 5.87 in Phases 2 and 3

  8. 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

  9. Melophagus ovinus e Trypanosoma (Megatrypanum melophagium em ovinos no Estado de Minas Gerais, Brasil Melophagus ovinus and Trypanosoma (Megatrypanum melophagium in ovines in the State of Minas Gerais, Brasil

    Directory of Open Access Journals (Sweden)

    José Oswaldo Costa

    1983-03-01

    Full Text Available Neste trabalho Melophagus ovinus é identificado pela primeira vez no Estado de Minas Gerais e Trypanosoma (Megatrypanum melophagium tem sua primeira ocorrência registrada no Brasil.Melophagus ovinus is identified for the first time in Minas Gerais State and Trypanosoma (Megatrypanum melophagium in Brazil.

  10. 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

  11. 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.

  12. Processing of the glycosomal matrix-protein import receptor PEX5 of Trypanosoma brucei

    International Nuclear Information System (INIS)

    Gualdrón-López, Melisa; Michels, Paul A.M.

    2013-01-01

    Highlights: ► Most eukaryotic cells have a single gene for the peroxin PEX5. ► PEX5 is sensitive to in vitro proteolysis in distantly related organisms. ► TbPEX5 undergoes N-terminal truncation in vitro and possibly in vivo. ► Truncated TbPEX5 is still capable of binding PTS1-containing proteins. ► PEX5 truncation is physiologically relevant or an evolutionary conserved artifact. -- Abstract: Glycolysis in kinetoplastid protists such as Trypanosoma brucei is compartmentalized in peroxisome-like organelles called glycosomes. Glycosomal matrix-protein import involves a cytosolic receptor, PEX5, which recognizes the peroxisomal-targeting signal type 1 (PTS1) present at the C-terminus of the majority of matrix proteins. PEX5 appears generally susceptible to in vitro proteolytic processing. On western blots of T. brucei, two PEX5 forms are detected with apparent M r of 100 kDa and 72 kDa. 5′-RACE-PCR showed that TbPEX5 is encoded by a unique transcript that can be translated into a protein of maximally 72 kDa. However, recombinant PEX5 migrates aberrantly in SDS–PAGE with an apparent M r of 100 kDa, similarly as observed for the native peroxin. In vitro protease susceptibility analysis of native and 35 S-labelled PEX5 showed truncation of the 100 kDa form at the N-terminal side by unknown parasite proteases, giving rise to the 72 kDa form which remains functional for PTS1 binding. The relevance of these observations is discussed

  13. Processing of the glycosomal matrix-protein import receptor PEX5 of Trypanosoma brucei

    Energy Technology Data Exchange (ETDEWEB)

    Gualdrón-López, Melisa [Research Unit for Tropical Diseases, de Duve Institute, Université catholique de Louvain, Brussels (Belgium); Michels, Paul A.M., E-mail: paul.michels@uclouvain.be [Research Unit for Tropical Diseases, de Duve Institute, Université catholique de Louvain, Brussels (Belgium)

    2013-02-01

    Highlights: ► Most eukaryotic cells have a single gene for the peroxin PEX5. ► PEX5 is sensitive to in vitro proteolysis in distantly related organisms. ► TbPEX5 undergoes N-terminal truncation in vitro and possibly in vivo. ► Truncated TbPEX5 is still capable of binding PTS1-containing proteins. ► PEX5 truncation is physiologically relevant or an evolutionary conserved artifact. -- Abstract: Glycolysis in kinetoplastid protists such as Trypanosoma brucei is compartmentalized in peroxisome-like organelles called glycosomes. Glycosomal matrix-protein import involves a cytosolic receptor, PEX5, which recognizes the peroxisomal-targeting signal type 1 (PTS1) present at the C-terminus of the majority of matrix proteins. PEX5 appears generally susceptible to in vitro proteolytic processing. On western blots of T. brucei, two PEX5 forms are detected with apparent M{sub r} of 100 kDa and 72 kDa. 5′-RACE-PCR showed that TbPEX5 is encoded by a unique transcript that can be translated into a protein of maximally 72 kDa. However, recombinant PEX5 migrates aberrantly in SDS–PAGE with an apparent M{sub r} of 100 kDa, similarly as observed for the native peroxin. In vitro protease susceptibility analysis of native and {sup 35}S-labelled PEX5 showed truncation of the 100 kDa form at the N-terminal side by unknown parasite proteases, giving rise to the 72 kDa form which remains functional for PTS1 binding. The relevance of these observations is discussed.

  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. Ocorrência de Trypanosoma evansi em eqüinos no município de Cruz Alta, RS, Brasil Occurrence of Trypanosoma evansi in equines in Cruz Alta, RS, Brazil

    Directory of Open Access Journals (Sweden)

    Régis Adriel Zanette

    2008-08-01

    Full Text Available O objetivo deste trabalho foi relatar a ocorrência de Trypanosoma evansi em eqüinos no município de Cruz Alta, Estado do Rio Grande do Sul, abordando aspectos epidemiológicos e sinais clínicos da infecção. A tripanosomose ocorreu em uma propriedade rural no município de Cruz Alta. Ao exame clínico, observou-se que quatro dos animais apresentavam marcha oscilante, com incoordenação dos membros posteriores. No entanto, eles estavam em bom estado nutricional, sem febre, bem hidratados e alimentavam-se normalmente. Foram coletadas amostras de sangue das éguas para hemograma, sendo identificado aumento das proteínas plasmáticas, leucocitose, eosinofilia e linfocitose em animais com sinais clínicos. No esfregaço sangüíneo periférico, observou-se a forma flagelada do T. evansi em três dos eqüinos.This study aimed at describing the occurrence of Trypanosoma evansi in equines from the city of Cruz Alta, RS, Brazil, relating epidemiological aspects and clinical signs of the infection. The tripanosomiasis occurred in a rural area of Cruz Alta, RS. Clinical signs presented by four animals were stiff and incoordinated gait of the pelvic members, although they were in good nutritional status, without fever, well-hydrated and eating normally. Blood samples were collected from the mares for hemogram. Increased levels of plasmatic proteins, leukocytosis, eosinophilia, and limphocytosis were observed in animals with clinical signs. Flagellated forms of T. evansi were observed in the blood smear of three animals.

  16. Proteomic Analysis of the Cell Cycle of Procylic Form Trypanosoma brucei.

    Science.gov (United States)

    Crozier, Thomas W M; Tinti, Michele; Wheeler, Richard J; Ly, Tony; Ferguson, Michael A J; Lamond, Angus I

    2018-06-01

    We describe a single-step centrifugal elutriation method to produce synchronous Gap1 (G1)-phase procyclic trypanosomes at a scale amenable for proteomic analysis of the cell cycle. Using ten-plex tandem mass tag (TMT) labeling and mass spectrometry (MS)-based proteomics technology, the expression levels of 5325 proteins were quantified across the cell cycle in this parasite. Of these, 384 proteins were classified as cell-cycle regulated and subdivided into nine clusters with distinct temporal regulation. These groups included many known cell cycle regulators in trypanosomes, which validates the approach. In addition, we identify 40 novel cell cycle regulated proteins that are essential for trypanosome survival and thus represent potential future drug targets for the prevention of trypanosomiasis. Through cross-comparison to the TrypTag endogenous tagging microscopy database, we were able to validate the cell-cycle regulated patterns of expression for many of the proteins of unknown function detected in our proteomic analysis. A convenient interface to access and interrogate these data is also presented, providing a useful resource for the scientific community. Data are available via ProteomeXchange with identifier PXD008741 (https://www.ebi.ac.uk/pride/archive/). © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. [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.

  6. 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

  7. Natural infection of the sand fly Phlebotomus kazeruni by Trypanosoma species in Pakistan

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    Iwata Hiroyuki

    2010-02-01

    Full Text Available Abstract The natural infection of phlebotomine sand flies by Leishmania parasites was surveyed in a desert area of Pakistan where cutaneous leishmaniasis is endemic. Out of 220 female sand flies dissected, one sand fly, Phlebotomus kazeruni, was positive for flagellates in the hindgut. Analyses of cytochrome b (cyt b, glycosomal glyceraldehyde phosphate dehydrogenase (gGAPDH and small subunit ribosomal RNA (SSU rRNA gene sequences identified the parasite as a Trypanosoma species of probably a reptile or amphibian. This is the first report of phlebotomine sand flies naturally infected with a Trypanosoma species in Pakistan. The possible infection of sand flies with Trypanosoma species should be taken into consideration in epidemiological studies of vector species in areas where leishmaniasis is endemic.

  8. 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.

  9. 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.

  10. [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.

  11. 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.

  12. Crystal structure of arginine methyltransferase 6 from Trypanosoma brucei.

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    Chongyuan Wang

    Full Text Available Arginine methylation plays vital roles in the cellular functions of the protozoan Trypanosoma brucei. The T. brucei arginine methyltransferase 6 (TbPRMT6 is a type I arginine methyltransferase homologous to human PRMT6. In this study, we report the crystal structures of apo-TbPRMT6 and its complex with the reaction product S-adenosyl-homocysteine (SAH. The structure of apo-TbPRMT6 displays several features that are different from those of type I PRMTs that were structurally characterized previously, including four stretches of insertion, the absence of strand β15, and a distinct dimerization arm. The comparison of the apo-TbPRMT6 and SAH-TbPRMT6 structures revealed the fine rearrangements in the active site upon SAH binding. The isothermal titration calorimetry results demonstrated that SAH binding greatly increases the affinity of TbPRMT6 to a substrate peptide derived from bovine histone H4. The western blotting and mass spectrometry results revealed that TbPRMT6 methylates bovine histone H4 tail at arginine 3 but cannot methylate several T. brucei histone tails. In summary, our results highlight the structural differences between TbPRMT6 and other type I PRMTs and reveal that the active site rearrangement upon SAH binding is important for the substrate binding of TbPRMT6.

  13. Meiosis and haploid gametes in the pathogen Trypanosoma brucei.

    Science.gov (United States)

    Peacock, Lori; Bailey, Mick; Carrington, Mark; Gibson, Wendy

    2014-01-20

    In eukaryote pathogens, sex is an important driving force in spreading genes for drug resistance, pathogenicity, and virulence. For the parasitic trypanosomes that cause African sleeping sickness, mating occurs during transmission by the tsetse vector and involves meiosis, but haploid gametes have not yet been identified. Here, we show that meiosis is a normal part of development in the insect salivary glands for all subspecies of Trypanosoma brucei, including the human pathogens. By observing insect-derived trypanosomes during the window of peak expression of meiosis-specific genes, we identified promastigote-like (PL) cells that interacted with each other via their flagella and underwent fusion, as visualized by the mixing of cytoplasmic red and green fluorescent proteins. PL cells had a short, wide body, a very long anterior flagellum, and either one or two kinetoplasts, but only the anterior kinetoplast was associated with the flagellum. Measurement of nuclear DNA contents showed that PL cells were haploid relative to diploid metacyclics. Trypanosomes are among the earliest diverging eukaryotes, and our results support the hypothesis that meiosis and sexual reproduction are ubiquitous in eukaryotes and likely to have been early innovations. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  14. mRNA localization mechanisms in Trypanosoma cruzi.

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    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.

  15. 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.

  16. Cancer in the parasitic protozoans Trypanosoma brucei and Toxoplasma gondii.

    Science.gov (United States)

    Lun, Zhao-Rong; Lai, De-Hua; Wen, Yan-Zi; Zheng, Ling-Ling; Shen, Ji-Long; Yang, Ting-Bo; Zhou, Wen-Liang; Qu, Liang-Hu; Hide, Geoff; Ayala, Francisco J

    2015-07-21

    Cancer is a general name for more than 100 malignant diseases. It is postulated that all cancers start from a single abnormal cell that grows out of control. Untreated cancers can cause serious consequences and deaths. Great progress has been made in cancer research that has significantly improved our knowledge and understanding of the nature and mechanisms of the disease, but the origins of cancer are far from being well understood due to the limitations of suitable model systems and to the complexities of the disease. In view of the fact that cancers are found in various species of vertebrates and other metazoa, here, we suggest that cancer also occurs in parasitic protozoans such as Trypanosoma brucei, a blood parasite, and Toxoplasma gondii, an obligate intracellular pathogen. Without treatment, these protozoan cancers may cause severe disease and death in mammals, including humans. The simpler genomes of these single-cell organisms, in combination with their complex life cycles and fascinating life cycle differentiation processes, may help us to better understand the origins of cancers and, in particular, leukemias.

  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. The Oral Antimalarial Drug Tafenoquine Shows Activity against Trypanosoma brucei.

    Science.gov (United States)

    Carvalho, Luis; Martínez-García, Marta; Pérez-Victoria, Ignacio; Manzano, José Ignacio; Yardley, Vanessa; Gamarro, Francisco; Pérez-Victoria, José M

    2015-10-01

    The protozoan parasite Trypanosoma brucei causes human African trypanosomiasis, or sleeping sickness, a neglected tropical disease that requires new, safer, and more effective treatments. Repurposing oral drugs could reduce both the time and cost involved in sleeping sickness drug discovery. Tafenoquine (TFQ) is an oral antimalarial drug belonging to the 8-aminoquinoline family which is currently in clinical phase III. We show here that TFQ efficiently kills different T. brucei spp. in the submicromolar concentration range. Our results suggest that TFQ accumulates into acidic compartments and induces a necrotic process involving cell membrane disintegration and loss of cytoplasmic content, leading to parasite death. Cell lysis is preceded by a wide and multitarget drug action, affecting the lysosome, mitochondria, and acidocalcisomes and inducing a depolarization of the mitochondrial membrane potential, elevation of intracellular Ca(2+), and production of reactive oxygen species. This is the first report of an 8-aminoquinoline demonstrating significant in vitro activity against T. brucei. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  19. 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.

  20. Effects of azadirachtin on Rhodnius prolixus: immunity and trypanosoma interaction

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    Patricia de Azambuja

    1992-01-01

    Full Text Available The effects of azadirachtin, a tetranortriterpenoid from the neem tree Aradirachta indica J. on both immunity and Trypanosoma cruzi interaction within Rhodniusprolixus and other triatomines, were presented Given through a blood meal, azadirachtin affected the immune reactivity as shown by a significant reduction in numbers of hemocytes and consequently nodule formation follwing challenge with Enterobacter cloacae ß12, reduction in ability to produce antibacterial activities in the hemolymph when injected with bacteria, and decreased ability to destroy the infection caused by inoculation of E. cloacae cells. A single dose of azadirachtin was able to block the development of T. cruzi in R. prolixus if given through the meal at different intervals, together with, before or after parasite infection. Similary, these results were observed with different triatomine species and different strains of T. cruzi. Azadirachtin induced a permanent resistance of the vector against reinfection with T. cruzi. The significance of these data is discussed in relation to the general mode of azadirachtin action in insects.

  1. 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.

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

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    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.

  3. 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.

  4. Phenolic Constituents of Medicinal Plants with Activity against Trypanosoma brucei

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    Ya Nan Sun

    2016-04-01

    Full Text Available Neglected tropical diseases (NTDs affect over one billion people all over the world. These diseases are classified as neglected because they impact populations in areas with poor financial conditions and hence do not attract sufficient research investment. Human African Trypanosomiasis (HAT or sleeping sickness, caused by the parasite Trypanosoma brucei, is one of the NTDs. The current therapeutic interventions for T. brucei infections often have toxic side effects or require hospitalization so that they are not available in the rural environments where HAT occurs. Furthermore, parasite resistance is increasing, so that there is an urgent need to identify novel lead compounds against this infection. Recognizing the wide structural diversity of natural products, we desired to explore and identify novel antitrypanosomal chemotypes from a collection of natural products obtained from plants. In this study, 440 pure compounds from various medicinal plants were tested against T. brucei by in a screening using whole cell in vitro assays. As the result, twenty-two phenolic compounds exhibited potent activity against cultures of T. brucei. Among them, eight compounds—4, 7, 11, 14, 15, 18, 20, and 21—showed inhibitory activity against T. brucei, with IC50 values below 5 µM, ranging from 0.52 to 4.70 μM. Based on these results, we attempt to establish some general trends with respect to structure-activity relationships, which indicate that further investigation and optimization of these derivatives might enable the preparation of potentially useful compounds for treating HAT.

  5. High positive predictive value of Gram stain on catheter-drawn blood samples for the diagnosis of catheter-related bloodstream infection in intensive care neonates.

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    Deleers, M; Dodémont, M; Van Overmeire, B; Hennequin, Y; Vermeylen, D; Roisin, S; Denis, O

    2016-04-01

    Catheter-related bloodstream infections (CRBSIs) remain a leading cause of healthcare-associated infections in preterm infants. Rapid and accurate methods for the diagnosis of CRBSIs are needed in order to implement timely and appropriate treatment. A retrospective study was conducted during a 7-year period (2005-2012) in the neonatal intensive care unit of the University Hospital Erasme to assess the value of Gram stain on catheter-drawn blood samples (CDBS) to predict CRBSIs. Both peripheral samples and CDBS were obtained from neonates with clinically suspected CRBSI. Gram stain, automated culture and quantitative cultures on blood agar plates were performed for each sample. The paired quantitative blood culture was used as the standard to define CRBSI. Out of 397 episodes of suspected CRBSIs, 35 were confirmed by a positive ratio of quantitative culture (>5) or a colony count of CDBS culture >100 colony-forming units (CFU)/mL. All but two of the 30 patients who had a CDBS with a positive Gram stain were confirmed as having a CRBSI. Seven patients who had a CDBS with a negative Gram stain were diagnosed as CRBSI. The sensitivity, specificity, positive predictive value and negative predictive value of Gram stain on CDBS were 80, 99.4, 93.3 and 98.1 %, respectively. Gram staining on CDBS is a viable method for rapidly (<1 h) detecting CRBSI without catheter withdrawal.

  6. Risk factors for central line-associated bloodstream infection in pediatric oncology patients with a totally implantable venous access port: A cohort study.

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    Viana Taveira, Michelle Ribeiro; Lima, Luciana Santana; de Araújo, Cláudia Corrêa; de Mello, Maria Júlia Gonçalves

    2017-02-01

    Totally implantable venous access ports (TIVAPs) are used for prolonged central venous access, allowing the infusion of chemotherapy and other fluids and improving the quality of life of children with cancer. TIVAPs were developed to reduce the infection rates associated with central venous catheters; however, infectious events remain common and have not been fully investigated in pediatric oncology patients. A retrospective cohort was formed to investigate risk factors for central line-associated bloodstream infection (CLABSI) in pediatric cancer patients. Sociodemographic, clinical, and TIVAP insertion-related variables were evaluated, with the endpoint being the first CLABSI. A Kaplan-Meier analysis was performed to determine CLABSI-free catheter survival. Overall, 188 children were evaluated over 77,541 catheter days, with 94 being diagnosed with CLABSI (50%). Although coagulase-negative staphylococci were the pathogens most commonly isolated, Gram-negative microorganisms (46.8%) were also prevalent. In the multivariate analysis, factors that increased the risk for CLABSI were TIVAP insertion prior to chemotherapy (risk ratio [RR] = 1.56; P Risk factors for CLABSI in pediatric cancer patients with a TIVAP may be related to the severity of the child's condition at catheter insertion. Insertion of the catheter before chemotherapy and unfavorable conditions such as malnutrition and bone marrow aplasia can increase the risk of CLABSI. Protocols must be revised and surveillance increased over the first 10 weeks of treatment. © 2016 Wiley Periodicals, Inc.

  7. 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.

  8. 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

  9. 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.

  10. Multifaceted antibiotic treatment analysis of methicillin-sensitive Staphylococcus aureus bloodstream infections.

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    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.

  11. Trends in Nosocomial Bloodstream Infections in a Burn Intensive Care Unit: an Eight-Year Survey

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    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

  12. Case-crossover study of Burkholderia cepacia complex bloodstream infection associated with contaminated intravenous bromopride.

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    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.

  13. Diversity of β-lactamases produced by imipenem resistant, Pseudomonas aeruginosa isolates from the bloodstream.

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    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.

  14. 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.

  15. Klebsiella pneumoniae bloodstream infections in neonates in a hospital in the Kingdom of Saudi Arabia.

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    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

  16. 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

  17. The Changing Epidemiology of Bloodstream Infections and Resistance in Hematopoietic Stem Cell Transplantation Recipients

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    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.

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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)

  10. 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)

  11. 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

  12. Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes

    Science.gov (United States)

    2013-01-01

    The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 105 tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34th and 35th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes. PMID:23289625

  13. 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.

  14. 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.

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

    Directory of Open Access Journals (Sweden)

    Rana Nagarkatti

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

  16. 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.

  17. 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.

  18. Molecular basis of mammalian cell invasion by Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    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

  19. Eco-epidemiological aspects of Trypanosoma cruzi, Trypanosoma rangeli and their vector (Rhodnius pallescens in Panama Generalidades do Trypanosoma cruzi, do Trypanosoma rangeli e do seu vetor (Rhodnius pallescens no Panamá

    Directory of Open Access Journals (Sweden)

    Ana Maria de Vasquez

    2004-08-01

    Full Text Available The eco-epidemiology of T. cruzi infection was investigated in the Eastern border of the Panama Canal in Central Panama. Between 1999 and 2000, 1110 triatomines were collected: 1050 triatomines (94.6% from palm trees, 27 (2.4% from periurban habitats and 33 (3.0% inside houses. All specimens were identified as R. pallescens. There was no evidence of vector domiciliation. Salivary glands from 380 R. pallescens revealed a trypanosome natural infection rate of 7.6%, while rectal ampoule content from 373 triatomines was 45%. Isoenzyme profiles on isolated trypanosomes demonstrated that 85.4% (n = 88 were T. cruzi and 14.6% (n = 15 were T. rangeli. Blood meal analysis from 829 R. pallescens demonstrated a zoophilic vector behavior, with opossums as the preferential blood source. Seroprevalence in human samples from both study sites was less than 2%. Our results demonstrate that T. cruzi survives in the area in balanced association with R. pallescens, and with several different species of mammals in their natural niches. However, the area is an imminent risk of infection for its population, consequently it is important to implement a community educational program regarding disease knowledge and control measures.A epidemiologia da infecção do T. cruzi foi investigada na margem oriental do canal do Panamá, na região central da Republica do Panamá. A informação obtida durante o estudo avaliou fatores de risco da doença de Chagas nesta área. Entre 1999 e 2000, 1110 triatomíneos foram coletados: 1050 triatomíneos (94,6% em palmeiras, 27 (2,4% em habitats periurbanos e 33 (3,0% no interior de casas. Todos os espécimens foram identificados como R. pallescens. Não havia nenhuma evidência de domiciliação do vetor. O exame de glândulas salivares de 380 R. pallescens revelaram taxa de infecção natural por Trypanosoma de 7,6%, mas o conteúdo da ampola rectal de 373 triatomíneos mostrou 45% de positividade. Os perfis de isoenzimas em

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Prevalence of Trypanosoma vivax in cattle in central Sudan

    International Nuclear Information System (INIS)

    Fadl, M.; Babiker, H.I.; Bakheit, M.A.; A Rahman, A.H.

    2000-01-01

    The study was conducted to validate an antibody-detection ELISA test (Ab-ELISA) using pre-coated ELISA plates with crude antigen preparation of Trypanosoma vivax and to study the prevalence of T. vivax infection in central Sudan. A total of 704 blood samples were collected from cattle in central Sudan, a known endemic area of T. vivax infection. Additionally, 74 blood samples were collected from northern Sudan (Atbra town), an area presumed to be T. vivax-free. Sera were collected during the period September 1998 to May 1999 during three different seasons (summer, autumn and winter). Under the existing laboratory conditions, the test showed a clear distinction between different controls, i.e. strong positive control (C++), weak positive control (C+), negative control (C-) and the conjugate control (Cc). A percent positivity of 25% was taken as a cut-off value to determine the positivity or negativity of the test. The acceptable optical density range of strong positive control (C++) was 0.65-1.22. Lower and upper percent positivity limits for different controls were also determined. The study showed that T. vivax is endemic in central Sudan with 1.4% prevalence based on parasitological examination and 29.26% on Ab-ELISA. The infection rate was significantly higher during the autumn and winter than in summer. Young cattle showed significantly lower infection rates than adults as indicated by both the parasitological and the Ab-ELISA test. In relation to husbandry practice, migratory cattle showed significantly higher rates of prevalence than resident cattle. There was no significant difference in average packed red cell volume (PCV) values between ELISA positive and ELISA negative animals. Calves of less than one year of age showed significantly lower PCV values when belonging to migratory herds than to resident herds. (author)

  3. 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

  4. 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.

  5. Cynaropicrin targets the trypanothione redox system in Trypanosoma brucei.

    Science.gov (United States)

    Zimmermann, Stefanie; Oufir, Mouhssin; Leroux, Alejandro; Krauth-Siegel, R Luise; Becker, Katja; Kaiser, Marcel; Brun, Reto; Hamburger, Matthias; Adams, Michael

    2013-11-15

    In mice cynaropicrin (CYN) potently inhibits the proliferation of Trypanosoma brucei-the causative agent of Human African Trypanosomiasis-by a so far unknown mechanism. We hypothesized that CYNs α,β-unsaturated methylene moieties act as Michael acceptors for glutathione (GSH) and trypanothione (T(SH)2), the main low molecular mass thiols essential for unique redox metabolism of these parasites. The analysis of this putative mechanism and the effects of CYN on enzymes of the T(SH)2 redox metabolism including trypanothione reductase, trypanothione synthetase, glutathione-S-transferase, and ornithine decarboxylase are shown. A two step extraction protocol with subsequent UPLC-MS/MS analysis was established to quantify intra-cellular CYN, T(SH)2, GSH, as well as GS-CYN and T(S-CYN)2 adducts in intact T. b. rhodesiense cells. Within minutes of exposure to CYN, the cellular GSH and T(SH)2 pools were entirely depleted, and the parasites entered an apoptotic stage and died. CYN also showed inhibition of the ornithine decarboxylase similar to the positive control eflornithine. Significant interactions with the other enzymes involved in the T(SH)2 redox metabolism were not observed. Alongside many other biological activities sesquiterpene lactones including CYN have shown antitrypanosomal effects, which have been postulated to be linked to formation of Michael adducts with cellular nucleophiles. Here the interaction of CYN with biological thiols in a cellular system in general, and with trypanosomal T(SH)2 redox metabolism in particular, thus offering a molecular explanation for the antitrypanosomal activity is demonstrated. At the same time, the study provides a novel extraction and analysis protocol for components of the trypanosomal thiol metabolism. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Rab23 is a flagellar protein in Trypanosoma brucei

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    Field Mark C

    2011-06-01

    Full Text Available Abstract Background Rab small GTPases are important mediators of membrane transport, and orthologues frequently retain similar locations and functions, even between highly divergent taxa. In metazoan organisms Rab23 is an important negative regulator of Sonic hedgehog signaling and is crucial for correct development and differentiation of cellular lineages by virtue of an involvement in ciliary recycling. Previously, we reported that Trypanosoma brucei Rab23 localized to the nuclear envelope 1, which is clearly inconsistent with the mammalian location and function. As T. brucei is unicellular the potential that Rab23 has no role in cell signaling was possible. Here we sought to further investigate the role(s of Rab23 in T. brucei to determine if Rab23 was an example of a Rab protein with divergent function in distinct taxa. Methods/major findings The taxonomic distribution of Rab23 was examined and compared with the presence of flagella/cilia in representative taxa. Despite evidence for considerable secondary loss, we found a clear correlation between a conventional flagellar structure and the presence of a Rab23 orthologue in the genome. By epitope-tagging, Rab23 was localized and found to be present at the flagellum throughout the cell cycle. However, RNAi knockdown did not result in a flagellar defect, suggesting that Rab23 is not required for construction or maintenance of the flagellum. Conclusions The location of Rab23 at the flagellum is conserved between mammals and trypanosomes and the Rab23 gene is restricted to flagellated organisms. These data may suggest the presence of a Rab23-mediated signaling mechanism in trypanosomes.

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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...

  12. 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.

  13. 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

  14. Analysis of the mitochondrial maxicircle of Trypanosoma lewisi, a neglected human pathogen

    Czech Academy of Sciences Publication Activity Database

    Lin, R.-H.; Lai, D.-H.; Zheng, L.-L.; Wu, J.; Lukeš, Julius; Hide, G.; Lun, Z.-R.

    2015-01-01

    Roč. 8, 30 December 2015 (2015), s. 665 ISSN 1756-3305 Institutional support: RVO:60077344 Keywords : Trypanosoma lewisi * Kinetoplast maxicircle * Mitochondrial DNA * RNA editing * Palindrome Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.234, year: 2015

  15. YCF45 protein, usually associated with plastids, is targeted into the mitochondrion of Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Týč, Jiří; Long, Shaojun; Jirků, Milan; Lukeš, Julius

    2010-01-01

    Roč. 173, č. 1 (2010), s. 43-47 ISSN 0166-6851 R&D Projects: GA ČR GA204/09/1667 Institutional research plan: CEZ:AV0Z60220518 Keywords : Trypanosoma * Plastid * Mitochondrion * Targeting * YCF45 * Horizontal gene transfer Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.875, year: 2010

  16. AcSDKP is down-regulated in anaemia induced by Trypanosoma ...

    African Journals Online (AJOL)

    We studied the responses of a tetrapeptide, AcSDKP, and IL-10, and their association with bone marrow nucleated cells in a Trypanosoma brucei brucei GVR35 experimental infection model. Methods Mouse infection was done intraperitoneally with 1 × 103 trypanosomes/mL. Mice were either infected or left uninfected (N ...

  17. 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 ...

  18. Molecular variation of Trypanosoma brucei subspecies as revealed by AFLP fingerprinting

    NARCIS (Netherlands)

    Agbo, E.E.C.; Majiwa, P.A.O.; Claassen, H.J.H.M.; Pas, te M.F.W.

    2002-01-01

    Genetic analysis of Trypanosoma spp. depends on the detection of variation between strains. We have used the amplified fragment length polymorphism (AFLP) technique to develop a convenient and reliable method for genetic characterization of Trypanosome (sub)species. AFLP accesses multiple

  19. Futile import of tRNAs and proteins into the mitochondrion of Trypanosoma brucei evansi

    Czech Academy of Sciences Publication Activity Database

    Paris, Zdeněk; Hashimi, Hassan; Lun, Sijia; Alfonzo, J. D.; Lukeš, Julius

    2011-01-01

    Roč. 176, č. 2 (2011), 116-120 ISSN 0166-6851 R&D Projects: GA ČR GA204/09/1667; GA MŠk LC07032 Institutional research plan: CEZ:AV0Z60220518 Keywords : Trypanosoma * tRNA * Protein import * Mitochondrion * Kinetoplast Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.551, year: 2011

  20. Functions and cellular localization of cysteine desulfurase and selenocysteine lyase in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Poliak, Pavel; Van Hoewyk, D.; Oborník, Miroslav; Zíková, Alena; Stuart, K. D.; Tachezy, J.; Pilon, M.; Lukeš, Julius

    2010-01-01

    Roč. 277, č. 2 (2010), s. 383-393 ISSN 1742-464X R&D Projects: GA ČR GA204/09/1667 Institutional research plan: CEZ:AV0Z60220518 Keywords : Fe–S cluster * mitochondrion * RNAi * selenoprotein * Trypanosoma Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 3.129, year: 2010

  1. The promoter for a variant surface glycoprotein gene expression site in Trypanosoma brucei

    NARCIS (Netherlands)

    Zomerdijk, J. C.; Ouellette, M.; ten Asbroek, A. L.; Kieft, R.; Bommer, A. M.; Clayton, C. E.; Borst, P.

    1990-01-01

    The variant-specific surface glycoprotein (VSG) gene 221 of Trypanosoma brucei is transcribed as part of a 60 kb expression site (ES). We have identified the promoter controlling this multigene transcription unit by the use of 221 chromosome-enriched DNA libraries and VSG gene 221 expression site

  2. Molecular Confirmation of Trypanosoma evansi and Babesia bigemina in Cattle from Lower Egypt

    Directory of Open Access Journals (Sweden)

    Mahmoud M. Elhaig, Abdelfattah Selim, Mohamed M. Mahmoud and Eman K El-Gayar

    2016-11-01

    Full Text Available Trypanosomosis and babesiosis are economically important vector-borne diseases for animal health and productivity in developing countries. In Egypt, molecular epidemiological surveys on such diseases are scarce. In the present study, we examined 475 healthy and 25 clinically diagnosed cattle from three provinces in Lower Egypt, for Trypanosoma (T. and Babesia (B. infections using an ITS1 PCR assay that confirmed Trypanosoma species presence and an 18S rRNA assay that detected B. bigemina. Results confirmed Trypanosoma spp. and B. bigemina presence in 30.4% and 11% individuals, respectively, with eight animals (1.6% being co-infected with both hemoparasites. Subsequent type-specific PCRs revealed that all Trypanosoma PCR positive samples corresponded to T. evansi and that none of the animals harboured T. brucei gambiense or T. brucei rhodesiense. Nucleotide sequencing of the variable surface glycoprotein revealed the T. evansi cattle strain to be most closely related (99% nucleotide sequence identity to strains previously detected in dromedary camels in Egypt, while the 18S rRNA gene phylogeny confirmed the presence of a unique B. bigemina haplotype closely related to strains from Turkey and Brazil. Statistically significant differences in PCR prevalence were noted with respect to gender, clinical status and locality. These results confirm the presence of high numbers of carrier animals and signal the need for expanded surveillance and control efforts.

  3. Procyclic Trypanosoma brucei do not use Krebs cycle activity for energy generation

    NARCIS (Netherlands)

    Weelden, van S.W.H.; Fast, B.; Vogt, A.; Meer, van der P.; Saas, J.; Hellemond, van J.J.; Tielens, A.G.M.; Boshart, M.

    2003-01-01

    The importance of a functional Krebs cycle for energy generation in the procyclic stage of Trypanosoma brucei was investigated under physiological conditions during logarithmic phase growth of a pleomorphic parasite strain. Wild type procyclic cells and mutants with targeted deletion of the gene

  4. 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

  5. Biodemes and zymodemes of Trypanosoma cruzi strains: correlations with clinical data and experimental pathology

    Directory of Open Access Journals (Sweden)

    Sonia G. Andrade

    1997-02-01

    Full Text Available With the objective of establishing biological and biochemical characteristics of a significant number of Trypanosoma cruzi strains from different geographical areas, 138 strains isolated from naturally infected humans, triatomine or vertebrate hosts were studied; 120 were isolated from different areas of Brazil and 18 from other South and Central American countries. Inocula from triatomine or culture forms were injected into suckling Swiss mice, followed by passages into mice 10 to 12 g. Biological characters and histopathological study permitted the inclusion of the strains into three Types or biodemes: I, II, III. Isoenzymic analysis confirmed a correspondence between the biodemes and zymodemes : Type I and Z2b, Type II and Z2, Type III and Z1. Results showed the ubiquitary distribution of the several types of strains. The predominance of the same Type and zymodeme in one geographical area was confirmed : Type II strains among the human cases from eastern Bahia and east of Goiás; Type III strains from humans of north Brazil and Central America and from silvatic vectors or vertebrates from other geographical areas. The biological types of strains correlate with different histopathological lesions considering cardiac involvement and neuronal lesions. These findings suggest that the biological behavior together with isoenzymes patterns and pathological pictures in the vertebrate host can be an important tool for establishing correlations between strains behavior and clinico-pathological manifestations of Chagas' disease in different geographical areas.Foram estudados os caracteres biológicos e isoenzimáticos de 138 cepas do Trypanosoma cruzi de diferentes áreas geográficas, sendo 120 do Brasil e 18 de outros paises da América do Sul e Central. Camundongos recém-nascidos foram inoculados com formas metacíclicas de triatomineos ou de culturas axenicas, seguindo-se passagem em camundongo de 10 a 12g. Os caracteres biológicos e o estudo

  6. Trypanocidal activity of human plasma on Trypanosoma evansi in mice Atividade tripanocida do plasma humano sobre Trypanosoma evansi em camundongos

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    Aleksandro Schafer Da Silva

    2012-03-01

    Full Text Available This study aimed to test an alternative protocol with human plasma to control Trypanosoma evansi infection in mice. Plasma from an apparently 27-year-old healthy male, blood type A+, was used in the study. A concentration of 100 mg.dL-1 apolipoprotein L1 (APOL1 was detected in the plasma. Forty mice were divided into four groups with 10 animals each. Group A comprised uninfected animals. Mice from groups B, C and D were inoculated with a T. evansi isolate. Group B was used as a positive control. At three days post-infection (DPI, the mice were administered intraperitoneally with human plasma. A single dose of 0.2 mL plasma was given to those in group C. The mice from group D were administered five doses of 0.2 mL plasma with a 24 hours interval between the doses. Group B showed high increasing parasitemia that led to their death within 5 DPI. Both treatments eliminated parasites from the blood and increased the longevity of animals. An efficacy of 50 (group C and 80% (group D of human plasma trypanocidal activity was found using PCR. This therapeutic success was likely achieved in the group D due to their higher levels of APOL1 compared with group C.Este estudo teve como objetivo testar um protocolo alternativo com plasma humano para controlar a infecção por Trypanosoma evansi em camundongos. O plasma foi oriundo de um homem aparentemente saudável, com idade entre 27 anos e tipo de sangue A+. Foi detectada uma concentração de 100 mg.dL -1 de apolipoproteína L1 (APOL1 no plasma. Quarenta camundongos foram divididos em quatro grupos, contendo dez animais cada. Grupo A, composto de animais não infectados. Os roedores dos grupos B, C e D foram inoculados intraperitonealmente com um isolado de T. evansi. O Grupo B foi usado como um controle positivo. Três dias pós-infecção (DPI, os camundongos foram tratados com plasma humano. Uma dose única de 0,2 mL de plasma foi administrada nos roedores do grupo C. Os ratos do grupo D receberam cinco

  7. EXPERIMENTAL INFECTION BY Trypanosoma vivax IN GOATS INFECÇÃO EXPERIMENTAL EM CAPRINOS COM Trypanosoma vivax

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    Francisco David Nascimento Sousa

    2008-10-01

    Full Text Available

    Four goats were infected intravenously with 1.0 mL of cattle blood containing about 1.25 x 105 Trypanosoma vivax derived from spontaneous outbreak in cattle at Catolé do Rocha city, Paraíba, Brazil. Other four goats were used as controls. Parasitemia and body temperature were determined daily for 40 days. Animals were weighted each 7 days, and blood samples for blood cells counts were collected each 5 days. It was obtained a sample of liquor from each animal before death; cerebrospinal fluid samples were submitted to biochemical and cytological evaluations, density determination and parasite detection. A positive correlation was found between body temperature and parasitemia in infected animals. These animals presented anemia, leukopenia, hypoglycemia, decreased serum levels of total proteins and cholesterol, and nervous symptoms. Examination of cerebrospinal fluid resulted in decrease of glucose levels and increase in lactate dehydrogenase, cell counts and presence of the parasite. At necropsy it was found pale carcass, generalized infartation of lymphonodes, pulmonary edema, and liquid accumulation of pericardium. Histological changes were characterized by interstitial pneumonia, miocarditis, cardiac fibrosis, meningitis, and encephalitis. All observed changes confirm patogenicity of T. vivax.

    KEY WORDS: Experimental infection, trypanosomiasis, patogenicity.

    Quatro caprinos foram infectados experimentalmente por via intravenosa com 1,0 ml de sangue contendo aproximadamente 1,25 x 105 tripanossomas/ml, utilizando-se um isolado de Trypanosoma vivax de bovinos infectados naturalmente no município de Catolé do Rocha, Paraíba. A parasitemia e a temperatura foram determinadas diariamente durante quarenta dias. A cada cinco dias realizaram-se coletas de sangue para hemograma e análise bioquímica sérica. Antes do

  8. 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.

  9. 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

  10. 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

  11. 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.

  12. Cost Analysis of Implementing Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry Plus Real-Time Antimicrobial Stewardship Intervention for Bloodstream Infections.

    Science.gov (United States)

    Patel, Twisha S; Kaakeh, Rola; Nagel, Jerod L; Newton, Duane W; Stevenson, James G

    2017-01-01

    Studies evaluating rapid diagnostic testing plus stewardship intervention have consistently demonstrated improved clinical outcomes for patients with bloodstream infections. However, the cost of implementing new rapid diagnostic testing can be significant, and such testing usually does not generate additional revenue. There are minimal data evaluating the impact of adding matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) for rapid organism identification and dedicating pharmacy stewardship personnel time on the total hospital costs. A cost analysis was performed utilizing patient data generated from the hospital cost accounting system and included additional costs of MALDI-TOF equipment, supplies and personnel, and dedicated pharmacist time for blood culture review and of making interventions to antimicrobial therapy. The cost analysis was performed from a hospital perspective for 3-month blocks before and after implementation of MALDI-TOF plus stewardship intervention. A total of 480 patients with bloodstream infections were included in the analysis: 247 in the preintervention group and 233 in the intervention group. Thirty-day mortality was significantly improved in the intervention group (12% versus 21%, P cost per bloodstream infection was lower in the intervention group ($42,580 versus $45,019). Intensive care unit cost per bloodstream infection accounted for the largest share of the total costs in each group and was also lower in the intervention group ($10,833 versus $13,727). Implementing MALDI-TOF plus stewardship review and intervention decreased mortality for patients with bloodstream infections. Despite the additional costs of implementing MALDI-TOF and of dedicating pharmacy stewardship personnel time to interventions, the total hospital costs decreased by $2,439 per bloodstream infection, for an approximate annual cost savings of $2.34 million. Copyright © 2016 American Society for Microbiology.

  13. Borrelia burgdorferi outer surface protein C (OspC) binds complement component C4b and confers bloodstream survival.

    Science.gov (United States)

    Caine, Jennifer A; Lin, Yi-Pin; Kessler, Julie R; Sato, Hiromi; Leong, John M; Coburn, Jenifer

    2017-12-01

    Borrelia burgdorferi (Bb) is the causative agent of Lyme disease in the United States, a disease that can result in carditis, and chronic and debilitating arthritis and/or neurologic symptoms if left untreated. Bb survives in the midgut of the Ixodes scapularis tick, or within tissues of immunocompetent hosts. In the early stages of infection, the bacteria are present in the bloodstream where they must resist clearance by the innate immune system of the host. We have found a novel role for outer surface protein C (OspC) from B. burgdorferi and B. garinii in interactions with the complement component C4b and bloodstream survival in vivo. Our data show that OspC inhibits the classical and lectin complement pathways and competes with complement protein C2 for C4b binding. Resistance to complement is important for maintenance of the lifecycle of Bb, enabling survival of the pathogen within the host as well as in the midgut of a feeding tick when ospC expression is induced. © 2017 John Wiley & Sons Ltd.

  14. Ravuconazole self-emulsifying delivery system: in vitro activity against Trypanosoma cruzi amastigotes and in vivo toxicity

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    Spósito PA

    2017-05-01

    , ravuconazole–SEDDS and each excipient were evaluated in vitro at equivalent ravuconazole concentrations needed to inhibit 50% or 90% (IC50 and IC90, respectively of the intracellular amastigote form of the parasite in a cardiomyocyte cell line. The results showed a clear improvement of the ravuconazole anti-T. cruzi activity when associated with SEDDS. Based on our results, the repurposing of ravuconazole in SEDDS dosage form is a strategy that deserves further in vivo investigation in preclinical studies for the treatment of human T. cruzi infections. Keywords: ravuconazole, self-emulsifying drug delivery, asymmetric flow field-flow fractionation, Trypanosoma cruzi, Chagas disease, in vitro activity

  15. Trypanosoma cruzi Epimastigotes Are Able to Store and Mobilize High Amounts of Cholesterol in Reservosome Lipid Inclusions

    Science.gov (United States)

    Pereira, Miria G.; Nakayasu, Ernesto S.; Sant'Anna, Celso; De Cicco, Nuccia N. T.; Atella, Georgia C.; de Souza, Wanderley; Almeida, Igor C.; Cunha-e-Silva, Narcisa

    2011-01-01

    Background Reservosomes are lysosome-related organelles found in Trypanosoma cruzi epimastigotes. They represent the last step in epimastigote endocytic route, accumulating a set of proteins and enzymes related to protein digestion and lipid metabolism. The reservosome matrix contains planar membranes, vesicles and lipid inclusions. Some of the latter may assume rectangular or sword-shaped crystalloid forms surrounded by a phospholipid monolayer, resembling the cholesterol crystals in foam cells. Methodology/Principal Findings Using Nile Red fluorimetry and fluorescence microscopy, as well as electron microscopy, we have established a direct correlation between serum concentration in culture medium and the presence of crystalloid lipid inclusions. Starting from a reservosome purified fraction, we have developed a fractionation protocol to isolate lipid inclusions. Gas-chromatography mass-spectrometry (GC-MS) analysis revealed that lipid inclusions are composed mainly by cholesterol and cholesterol esters. Moreover, when the parasites with crystalloid lipid-loaded reservosomes were maintained in serum free medium for 48 hours the inclusions disappeared almost completely, including the sword shaped ones. Conclusions/Significance Taken together, our results suggest that epimastigote forms of T. cruzi store high amounts of neutral lipids from extracellular medium, mostly cholesterol or cholesterol esters inside reservosomes. Interestingly, the parasites are able to disassemble the reservosome cholesterol crystalloid inclusions when submitted to serum starvation. PMID:21818313

  16. Mating compatibility in the parasitic protist Trypanosoma brucei.

    Science.gov (United States)

    Peacock, Lori; Ferris, Vanessa; Bailey, Mick; Gibson, Wendy

    2014-02-21

    Genetic exchange has been described in several kinetoplastid parasites, but the most well-studied mating system is that of Trypanosoma brucei, the causative organism of African sleeping sickness. Sexual reproduction takes place in the salivary glands (SG) of the tsetse vector and involves meiosis and production of haploid gametes. Few genetic crosses have been carried out to date and consequently there is little information about the mating compatibility of different trypanosomes. In other single-celled eukaryotes, mating compatibility is typically determined by a system of two or more mating types (MT). Here we investigated the MT system in T. brucei. We analysed a large series of F1, F2 and back crosses by pairwise co-transmission of red and green fluorescent cloned cell lines through experimental tsetse flies. To analyse each cross, trypanosomes were cloned from fly SG containing a mixture of both parents, and genotyped by microsatellites and molecular karyotype. To investigate mating compatibility at the level of individual cells, we directly observed the behaviour of SG-derived gametes in intra- or interclonal mixtures of red and green fluorescent trypanosomes ex vivo. Hybrid progeny were found in all F1 and F2 crosses and most of the back crosses. The success of individual crosses was highly variable as judged by the number of hybrid clones produced, suggesting a range of mating compatibilities among F1 progeny. As well as hybrids, large numbers of recombinant genotypes resulting from intraclonal mating (selfers) were found in some crosses. In ex vivo mixtures, red and green fluorescent trypanosome gametes were observed to pair up and interact via their flagella in both inter- and intraclonal combinations. While yellow hybrid trypanosomes were frequently observed in interclonal mixtures, such evidence of cytoplasmic exchange was rare in the intraclonal mixtures. The outcomes of individual crosses, particularly back crosses, were variable in numbers of both

  17. 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

  18. Intraclonal mating occurs during tsetse transmission of Trypanosoma brucei

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    Ferris Vanessa

    2009-09-01

    Full Text Available Abstract Background Mating in Trypanosoma brucei is a non-obligatory event, triggered by the co-occurrence of different strains in the salivary glands of the vector. Recombinants that result from intra- rather than interclonal mating have been detected, but only in crosses of two different trypanosome strains. This has led to the hypothesis that when trypanosomes recognize a different strain, they release a diffusible factor or pheromone that triggers mating in any cell in the vicinity whether it is of the same or a different strain. This idea assumes that the trypanosome can recognize self and non-self, although there is as yet no evidence for the existence of mating types in T. brucei. Results We investigated intraclonal mating in T. b. brucei by crossing red and green fluorescent lines of a single strain, so that recombinant progeny can be detected in the fly by yellow fluorescence. For strain 1738, seven flies had both red and green trypanosomes in the salivary glands and, in three, yellow trypanosomes were also observed, although they could not be recovered for subsequent analysis. Nonetheless, both red and non-fluorescent clones from these flies had recombinant genotypes as judged by microsatellite and karyotype analyses, and some also had raised DNA contents, suggesting recombination or genome duplication. Strain J10 produced similar results indicative of intraclonal mating. In contrast, trypanosome clones recovered from other flies showed that genotypes can be transmitted with fidelity. When a yellow hybrid clone expressing both red and green fluorescent protein genes was transmitted, the salivary glands contained a mixture of fluorescent-coloured trypanosomes, but only yellow and red clones were recovered. While loss of the GFP gene in the red clones could have resulted from gene conversion, some of these clones showed loss of heterozygosity and raised DNA contents as in the other single strain transmissions. Our observations suggest

  19. 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

  20. Zoonotic trypanosomes in South East Asia : attempts to control Trypanosoma lewisi using human and animal trypanocidal drugs

    OpenAIRE

    Desquesnes, M.; Yangtara, S.; Kunphukhieo, P.; Jittapalapong, S.; Herder, Stéphane

    2016-01-01

    Beside typical human trypanosomes responsible of sleeping sickness in Africa and Chagas disease in Latin America, there is a growing number of reported atypical human infections due to Trypanosoma evansi, a livestock parasite, or Trypanosoma lewisi, a rat parasite, especially in Asia. Drugs available for the treatment of T. brucei ssp. in humans are obviously of choice for the control of T. evansi because it is derived from T. brucei. However, concerning T. lewisi, there is an urgent need to ...

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

    Science.gov (United States)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  3. 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

  4. 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

  5. Species-Specific and Drug-Specific Differences in Susceptibility of Candida Biofilms to Echinocandins: Characterization of Less Common Bloodstream Isolates

    Science.gov (United States)

    Simitsopoulou, Maria; Peshkova, Pavla; Tasina, Efthymia; Katragkou, Aspasia; Kyrpitzi, Daniela; Velegraki, Aristea; Walsh, Thomas J.

    2013-01-01

    Candida species other than Candida albicans are increasingly recognized as causes of biofilm-associated infections. This is a comprehensive study that compared the in vitro activities of all three echinocandins against biofilms formed by different common and infrequently identified Candida isolates. We determined the activities of anidulafungin (ANID), caspofungin (CAS), and micafungin (MFG) against planktonic cells and biofilms of bloodstream isolates of C. albicans (15 strains), Candida parapsilosis (6 strains), Candida lusitaniae (16 strains), Candida guilliermondii (5 strains), and Candida krusei (12 strains) by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] assay. Planktonic and biofilm MICs were defined as ≥50% fungal damage. Planktonic cells of all Candida species were susceptible to the three echinocandins, with MICs of ≤1 mg/liter. By comparison, differences in the MIC profiles of biofilms in response to echinocandins existed among the Candida species. Thus, C. lusitaniae and C. guilliermondii biofilms were highly recalcitrant to all echinocandins, with MICs of ≥32 mg/liter. In contrast, the MICs of all three echinocandins for C. albicans and C. krusei biofilms were relatively low (MICs ≤ 1 mg/liter). While echinocandins exhibited generally high MICs against C. parapsilosis biofilms, MFG exhibited the lowest MICs against these isolates (4 mg/liter). A paradoxical growth effect was observed with CAS concentrations ranging from 8 to 64 mg/liter against C. albicans and C. parapsilosis biofilms but not against C. krusei, C. lusitaniae, or C. guilliermondii. While non-albicans Candida planktonic cells were susceptible to all echinocandins, there were drug- and species-specific differences in susceptibility among biofilms of the various Candida species, with C. lusitaniae and C. guilliermondii exhibiting profiles of high MICs of the three echinocandins. PMID:23529739

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

    Directory of Open Access Journals (Sweden)

    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. DNA microarray genotyping and virulence and antimicrobial resistance gene profiling of methicillin-resistant Staphylococcus aureus bloodstream isolates from renal patients.

    LENUS (Irish Health Repository)

    McNicholas, Sinead

    2012-02-01

    Thirty-six methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from renal patients were genetically characterized by DNA microarray analysis and spa typing. The isolates were highly clonal, belonging mainly to ST22-MRSA-IV. The immune evasion and enterotoxin gene clusters were found in 29\\/36 (80%) and 33\\/36 (92%) isolates, respectively.

  8. Central line-associated bloodstream infections in adult hematology patients with febrile neutropenia: an evaluation of surveillance definitions using differential time to blood culture positivity.

    Science.gov (United States)

    Freeman, Joshua T; Elinder-Camburn, Anna; McClymont, Catherine; Anderson, Deverick J; Bilkey, Mary; Williamson, Deborah A; Berkahn, Leanne; Roberts, Sally A

    2013-01-01

    We used differential time to positivity between central and peripheral blood cultures to evaluate the positive predictive value (PPV) of the National Healthcare Safety Network central line-associated bloodstream infection (CLABSI) surveillance definition among hematology patients with febrile neutropenia. The PPV was 27.7%, which suggests that, when the definition is applied to this population, CLABSI rates will be substantially overestimated.

  9. Beyond the bundle: a survey of central line-associated bloodstream infection prevention practices used in US and Canadian pediatric hospitals.

    Science.gov (United States)

    Klieger, Sarah B; Potter-Bynoe, Gail; Quach, Caroline; Sandora, Thomas J; Coffin, Susan E

    2013-11-01

    We surveyed US and Canadian pediatric hospitals about their use of central line-associated bloodstream infection (CLABSI) prevention strategies beyond typical insertion and maintenance bundles. We found wide variation in supplemental strategies across hospitals and in their penetration within hospitals. Future studies should assess specific adjunctive prevention strategies and CLABSI rates.

  10. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: An interrupted time series over a 10-year period

    NARCIS (Netherlands)

    Helder, O.K.; Brug, J.; van Goudoever, J.B.; Looman, C.W.N.; Reiss, I.K.M.; Kornelisse, R.F.

    2014-01-01

    Background Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. Methods An observational study with an interrupted

  11. Sequential hand hygiene promotion contributes to a reduced nosocomial bloodstream infection rate among very low-birth weight infants: an interrupted time series over a 10-year period

    NARCIS (Netherlands)

    Helder, Onno K.; Brug, Johannes; van Goudoever, Johannes B.; Looman, Caspar W. N.; Reiss, Irwin K. M.; Kornelisse, René F.

    2014-01-01

    Sustained high compliance with hand hygiene (HH) is needed to reduce nosocomial bloodstream infections (NBSIs). However, over time, a wash out effect often occurs. We studied the long-term effect of sequential HH-promoting interventions. An observational study with an interrupted time series

  12. DNA microarray genotyping and virulence and antimicrobial resistance gene profiling of methicillin-resistant Staphylococcus aureus bloodstream isolates from renal patients.

    LENUS (Irish Health Repository)

    McNicholas, Sinead

    2011-12-01

    Thirty-six methicillin-resistant Staphylococcus aureus (MRSA) bloodstream isolates from renal patients were genetically characterized by DNA microarray analysis and spa typing. The isolates were highly clonal, belonging mainly to ST22-MRSA-IV. The immune evasion and enterotoxin gene clusters were found in 29\\/36 (80%) and 33\\/36 (92%) isolates, respectively.

  13. Detection of mcr-1 encoding plasmid-mediated colistin-resistant Escherichia coli isolates from human bloodstream infection and imported chicken meat, Denmark 2015

    DEFF Research Database (Denmark)

    Hasman, H.; Hammerum, A. M.; Hansen, F.

    2015-01-01

    The plasmid-mediated colistin resistance gene, mcr-1, was detected in an Escherichia coli isolate from a Danish patient with bloodstream infection and in five E. coli isolates from imported chicken meat. One isolate from chicken meat belonged to the epidemic spreading sequence type ST131...

  14. High similarity of Trypanosoma cruzi kDNA genetic profiles detected by LSSP-PCR within family groups in an endemic area of Chagas disease in Brazil

    Directory of Open Access Journals (Sweden)

    Sandra Maria Alkmim-Oliveira

    2014-10-01

    Full Text Available Introduction Determining the genetic similarities among Trypanosoma cruzi populations isolated from different hosts and vectors is very important to clarify the epidemiology of Chagas disease. Methods An epidemiological study was conducted in a Brazilian endemic area for Chagas disease, including 76 chronic chagasic individuals (96.1% with an indeterminate form; 46.1% with positive hemoculture. Results T. cruzi I (TcI was isolated from one child and TcII was found in the remaining (97.1% subjects. Low-stringency single-specific-primer-polymerase chain reaction (LSSP-PCR showed high heterogeneity among TcII populations (46% of shared bands; however, high similarities (80-100% among pairs of mothers/children, siblings, or cousins were detected. Conclusions LSSP-PCR showed potential for identifying similar parasite populations among individuals with close kinship in epidemiological studies of Chagas disease.

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

    Science.gov (United States)

    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

  16. Characterization of plasma menbrane polypeptides of trypanosoma from bats Caracterização de polipeptídeos de membrana plasmática de tripanosomas de morcegos

    OpenAIRE

    R. T. Pinho; Giovanni de Simone

    1989-01-01

    Cell surface proteins of Trypanosoma dionisii, Trypanosoma vespertilionis and Trypanosoma sp. (M238) were radiodinated and their distribution both in the detergent-poor (DPP) and dertergent-enriched phase (DRP) was studied using a phase separation technique in Triton X-114 as well as polyacrylamide gel electrophoresis in sodium dodecyl sulphate (SDS-PAGE). Significant differences were observed in the proteins present in the DRP when the three species of trypanosoma were compared. Two major ba...

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

    Science.gov (United States)

    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

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

    DEFF Research Database (Denmark)

    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...

  19. A case of Trypanosoma congolense savannah type infection and its management in a dog

    Directory of Open Access Journals (Sweden)

    Peter Kimeli

    2014-12-01

    Full Text Available A case of Trypanosoma congolense savannah type infection in a 4-year old German shepherd dog weighing 26-kg was presented to the Small Animal Clinic, University of Nairobi, Kenya, with the history of anorexia and difficulty in breathing. The clinical manifestations were fever, pale mucous membrane, dyspnea and wasting. Blood examination revealed the existence of trypanosome parasites, and showed mild anemia. Internal Transcribed Spacer (ITS based polymerase chain reaction confirmed the presence of Trypanosoma congolense savannah type. Along with supporting therapy, the case was successfully managed using diminazene aceturate injection (dosed at 3.5 mg/kg body weight through intramuscular route. Complete recovery of the case was observed on day 6 of post-treatment.

  20. Anti-Trypanosoma cruzi and cytotoxic activities of Eugenia uniflora L.

    Science.gov (United States)

    Santos, Karla K A; Matias, Edinardo F F; Tintino, Saulo R; Souza, Celestina E S; Braga, Maria F B M; Guedes, Gláucia M M; Rolón, Miriam; Vega, Celeste; de Arias, Antonieta Rojas; Costa, José G M; Menezes, Irwin R A; Coutinho, Henrique D M

    2012-05-01

    Chagas disease is caused by Trypanosoma cruzi, being considered a public health problem. An alternative to combat this pathogen is the use of natural products isolated from fruits such as Eugenia uniflora, a plant used by traditional communities as food and medicine due to its antimicrobial and biological activities. Ethanolic extract from E. uniflora was used to evaluate in vitro anti-epimastigote and cytotoxic activity. This is the first record of anti-Trypanosoma activity of E. uniflora, demonstrating that a concentration presenting 50% of activity (EC(50)) was 62.76 μg/mL. Minimum inhibitory concentration (MIC) was ≤ 1024 μg/mL. Our results indicate that E. uniflora could be a source of plant-derived natural products with anti-epimastigote activity with low toxicity. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Proximity Interactions among Basal Body Components in Trypanosoma brucei Identify Novel Regulators of Basal Body Biogenesis and Inheritance

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    Hung Quang Dang

    2017-01-01

    Full Text Available The basal body shares similar architecture with centrioles in animals and is involved in nucleating flagellar axonemal microtubules in flagellated eukaryotes. The early-branching Trypanosoma brucei possesses a motile flagellum nucleated from the basal body that consists of a mature basal body and an adjacent pro-basal body. Little is known about the basal body proteome and its roles in basal body biogenesis and flagellar axoneme assembly in T. brucei. Here, we report the identification of 14 conserved centriole/basal body protein homologs and 25 trypanosome-specific basal body proteins. These proteins localize to distinct subdomains of the basal body, and several of them form a ring-like structure surrounding the basal body barrel. Functional characterization of representative basal body proteins revealed distinct roles in basal body duplication/separation and flagellar axoneme assembly. Overall, this work identified novel proteins required for basal body duplication and separation and uncovered new functions of conserved basal body proteins in basal body duplication and separation, highlighting an unusual mechanism of basal body biogenesis and inheritance in this early divergent eukaryote.

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

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. IL-6 is Upregulated in Late-Stage Disease in Monkeys Experimentally Infected with Trypanosoma brucei rhodesiense

    Directory of Open Access Journals (Sweden)

    Dawn Nyawira Maranga

    2013-01-01

    Full Text Available The management of human African trypanosomiasis (HAT is constrained by lack of simple-to-use diagnostic, staging, and treatment tools. The search for novel biomarkers is, therefore, essential in the fight against HAT. The current study aimed at investigating the potential of IL-6 as an adjunct parameter for HAT stage determination in vervet monkey model. Four adult vervet monkeys (Chlorocebus aethiops were experimentally infected with Trypanosoma brucei rhodesiense and treated subcuratively at 28 days after infection (dpi to induce late stage disease. Three noninfected monkeys formed the control group. Cerebrospinal fluid (CSF and blood samples were obtained at weekly intervals and assessed for various biological parameters. A typical HAT-like infection was observed. The late stage was characterized by significant (P<0.05 elevation of CSF IL-6, white blood cell count, and total protein starting 35 dpi with peak levels of these parameters coinciding with relapse parasitaemia. Brain immunohistochemical staining revealed an increase in brain glial fibrillary acidic protein expression indicative of reactive astrogliosis in infected animals which were euthanized in late-stage disease. The elevation of IL-6 in CSF which accompanied other HAT biomarkers indicates onset of parasite neuroinvasion and show potential for use as an adjunct late-stage disease biomarker in the Rhodesian sleeping sickness.

  5. The development of an enzyme-linked immunosorbent assay for Trypanosoma vivax antibodies and its use in epidemiological surveys

    Directory of Open Access Journals (Sweden)

    Claudio R Madruga

    2006-11-01

    Full Text Available There are data indicating that the distribution of Trypanosoma vivax in the Brazilian territory is expanding with potential to reach other areas, where the vectors are present. The detection of anti-trypanosomal antibodies in serum provides important information of the trypanosomal status in cattle herds. For this reason, an enzyme-linked immunosorbent assay (Tv-ELISA-Ab with crude antigen from one Brazilian isolate of T. vivax was developed and evaluated. The sensitivity and specificity were respectively 97.6 and 96.9%. In the evaluation of cross-reactions, three calves inoculated with T. evansi trypimastigotes blood forms showed optical densities (OD under the cut-off during the whole experimental period, except one at 45 days post-inoculation. With relation to Babesia bovis, B. bigemina, and Anaplasma marginale, which are endemic hemoparasites in the studied area, the cross-reactions were shown to be 5.7, 5.3, and 1.1%, respectively. The first serological survey of Pantanal and state of Pará showed that T. vivax is widespread, although regions within both areas had significantly different prevalences. Therefore, this Tv-ELISA-Ab may be a more appropriate test for epidemiological studies in developing countries because the diagnostic laboratories in most countries may be able to perform an ELISA, which is not true for polymerase chain reaction.

  6. Mast cell-nerve interaction in the colon of Trypanosoma cruzi-infected individuals with chagasic megacolon.

    Science.gov (United States)

    Martins, Patrícia Rocha; Nascimento, Rodolfo Duarte; Dos Santos, Aline Tomaz; de Oliveira, Enio Chaves; Martinelli, Patricia Massara; d'Avila Reis, Débora

    2018-04-01

    Chagas disease is an infection caused by the parasite Trypanosoma cruzi that affects millions of people worldwide and is endemic in Latin America. Megacolon is the most frequent complication of the digestive chronic form and happens due to lesions of the enteric nervous system. The neuronal lesions seem to initiate in the acute phase and persist during the chronic phase, albeit the mechanisms involved in this process are still debated. Among the cells of the immune system possibly involved in this pathological process is the mast cell (MC) due to its well-known role in the bi-directional communication between the immune and nervous systems. Using ultrastructural analysis, we found an increased number of degranulated MCs in close proximity to nerve fibers in infected patients when compared with uninfected controls. We also immunostained MCs for the two pro-inflammatory molecules tryptase and chymase, the first being also important in neuronal death. The number of MCs immunostained for tryptase or chymase was increased in patients with megacolon, whereas increased tryptase staining was additionally observed in patients without megacolon. Moreover, we detected the expression of the tryptase receptor PAR2 in neurons of the enteric nervous system, which correlated to the tryptase staining results. Altogether, the data presented herein point to the participation of MCs on the denervation process that occurs in the development of T. cruzi-induced megacolon.

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

    Directory of Open Access Journals (Sweden)

    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. Landscape epidemiology in urban environments: The example of rodent-borne Trypanosoma in Niamey, Niger.

    Science.gov (United States)

    Rossi, Jean-Pierre; Kadaouré, Ibrahima; Godefroid, Martin; Dobigny, Gauthier

    2017-10-05

    Trypanosomes are protozoan parasites found worldwide, infecting humans and animals. In the past decade, the number of reports on atypical human cases due to Trypanosoma lewisi or T. lewisi-like has increased urging to investigate the multiple factors driving the disease dynamics, particularly in cities where rodents and humans co-exist at high densities. In the present survey, we used a species distribution model, Maxent, to assess the spatial pattern of Trypanosoma-positive rodents in the city of Niamey. The explanatory variables were landscape metrics describing urban landscape composition and physiognomy computed from 8 land-cover classes. We computed the metrics around each data location using a set of circular buffers of increasing radii (20m, 40m, 60m, 80m and 100m). For each spatial resolution, we determined the optimal combination of feature class and regularization multipliers by fitting Maxent with the full dataset. Since our dataset was small (114 occurrences) we expected an important uncertainty associated to data partitioning into calibration and evaluation datasets. We thus performed 350 independent model runs with a training dataset representing a random subset of 80% of the occurrences and the optimal Maxent parameters. Each model yielded a map of habitat suitability over Niamey, which was transformed into a binary map implementing a threshold maximizing the sensitivity and the specificity. The resulting binary maps were combined to display the proportion of models that indicated a good environmental suitability for Trypanosoma-positive rodents. Maxent performed better with landscape metrics derived from buffers of 80m. Habitat suitability for Trypanosoma-positive rodents exhibited large patches linked to urban features such as patch richness and the proportion of landscape covered by concrete or tarred areas. Such inferences could be helpful in assessing areas at risk, setting of monitoring programs, public and medical staff awareness or even

  9. Genetic control of resistance to Trypanosoma brucei brucei infection in mice

    Czech Academy of Sciences Publication Activity Database

    Šíma, Matyáš; Havelková, Helena; Quan, L.; Svobodová, M.; Jarošíková, T.; Vojtíšková, Jarmila; Stassen, A. P. M.; Demant, P.; Lipoldová, Marie

    2011-01-01

    Roč. 5, č. 6 (2011), e1173 ISSN 1935-2735 R&D Projects: GA AV ČR IAA500520606; GA MŠk(CZ) LC06009 Grant - others:NIH-NCI(US) 1R01CA127162-01 Institutional research plan: CEZ:AV0Z50520514 Keywords : Trypanosoma brucei brucei * mouse recombinant congenic strains * Tbbr Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.716, year: 2011

  10. 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...

  11. 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...

  12. 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

  13. The import and function of diatom and plant frataxins in the mitochondrion of Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Long, Shaojun; Vávrová, Zuzana; Lukeš, Julius

    2008-01-01

    Roč. 162, č. 1 (2008), s. 100-104 ISSN 0166-6851 R&D Projects: GA AV ČR IAA500960705; GA MŠk LC07032; GA MŠk 2B06129; GA ČR GA204/06/1558 Institutional research plan: CEZ:AV0Z60220518 Keywords : frataxin * mitochondrion * Trypanosoma * diatom * evolutionary conservativeness * import Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.951, year: 2008

  14. DEAD-box RNA helicase is dispensable for mitochondrial translation in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Richterová, Lenka; Vávrová, Zuzana; Lukeš, Julius

    2011-01-01

    Roč. 127, č. 1 (2011), 300-303 ISSN 0014-4894 R&D Projects: GA ČR GA204/09/1667; GA MŠk LC07032; GA MŠk 2B06129 Institutional research plan: CEZ:AV0Z60220518 Keywords : Trypanosoma * Mitochondrial translation * RNA helicase * Cytochrome c oxidase * Mitochondrion Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.122, year: 2011

  15. Mitochondrial fatty acid synthesis is required for normal mitochondrial morphology and function in Trypanosoma brucei

    Czech Academy of Sciences Publication Activity Database

    Guler, J. L.; Kriegová, Eva; Smith, T. K.; Lukeš, Julius; Englund, P. T.

    2008-01-01

    Roč. 67, č. 5 (2008), s. 1125-1142 ISSN 0950-382X R&D Projects: GA ČR GA204/06/1558; GA MŠk LC07032; GA MŠk 2B06129 Grant - others:NIH(US) AI21334; Wellcome Trust(GB) 067441 Institutional research plan: CEZ:AV0Z60220518 Keywords : Trypanosoma * mitochondrion * fatty acid * RNA interference Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.213, year: 2008

  16. Disparate phenotypic effects from the knockdown of various Trypanosoma brucei cytochrome c oxidase subunits

    Czech Academy of Sciences Publication Activity Database

    Gnipová, Anna; Panicucci, Brian; Paris, Zdeněk; Verner, Zdeněk; Horváth, A.; Lukeš, Julius; Zíková, Alena

    2012-01-01

    Roč. 184, č. 2 (2012), s. 90-98 ISSN 0166-6851 R&D Projects: GA AV ČR KJB500960901; GA ČR GA204/09/1667 Institutional research plan: CEZ:AV0Z60220518 Keywords : Trypanosoma * RNA interference * Mitochondrion * Respiratory complexes * Cytochrome c oxidase Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.734, year: 2012 http://www.sciencedirect.com/science/article/pii/S0166685112001065#

  17. WGS-based surveillance of third-generation cephalosporin-resistant Escherichia coli from bloodstream infections in Denmark

    DEFF Research Database (Denmark)

    Roer, Louise; Hansen, Frank; Thomsen, Martin Christen Frølund

    2017-01-01

    clone, here observed for the first time in Denmark. Additionally, the analysis revealed three individual cases with possible persistence of closely related clones collected more than 13 months apart. Continuous WGS-based national surveillance of 3GC-R Ec , in combination with more detailed......-genome sequenced and characterized by using the batch uploader from the Center for Genomic Epidemiology (CGE) and automatically analysed using the CGE tools according to resistance profile, MLST, serotype and fimH subtype. Additionally, the phylogenetic relationship of the isolates was analysed by SNP analysis......To evaluate a genome-based surveillance of all Danish third-generation cephalosporin-resistant Escherichia coli (3GC-R Ec ) from bloodstream infections between 2014 and 2015, focusing on horizontally transferable resistance mechanisms. A collection of 552 3GC-R Ec isolates were whole...

  18. Nosocomial bloodstream infections in a Turkish university hospital: study of Gram-negative bacilli and their sensitivity patterns.

    Science.gov (United States)

    Köseoğlu , O; Kocagöz, S; Gür, D; Akova, M

    2001-06-01

    Treatment of nosocomial bacteraemia is usually governed by the surveillance results of the particular unit. Such results are especially important when antimicrobial resistance rates are high. Multiresistant isolates including Gram-negatives producing extended-spectrum beta-lactamases have been frequently reported in tertiary care units in Turkey. In this study, antimicrobial susceptibilities of Gram-negative blood isolates (n=348) were determined by microbroth dilution tests. The results showed carbapenems (meropenem and imipenem) to be uniformly more potent in vitro than any other drug against the Enterobacteriaceae. Quinolone antibiotics were more active in vitro than aminoglycosides against a range of bacteria. Gram-negative bloodstream isolates were highly resistant to many antimicrobial agents in the hospital. In order to prevent hospital infection and antimicrobial resistance, surveillance of aetiological agents must be performed regularly.

  19. Incidence of colonization and bloodstream infection with carbapenem-resistant Enterobacteriaceae in children receiving antineoplastic chemotherapy in Italy.

    Science.gov (United States)

    Caselli, Desiree; Cesaro, Simone; Fagioli, Franca; Carraro, Francesca; Ziino, Ottavio; Zanazzo, Giulio; Meazza, Cristina; Colombini, Antonella; Castagnola, Elio

    2016-02-01

    Few data are available on the incidence of carbapenemase-producing Enterobacteriaceae (CPE) infection or colonization in children receiving anticancer chemotherapy. We performed a nationwide survey among centers participating in the pediatric hematology-oncology cooperative study group (Associazione Italiana Ematologia Oncologia Pediatrica, AIEOP). During a 2-year observation period, we observed a threefold increase in the colonization rate, and a fourfold increase of bloodstream infection episodes, caused by CPE, with a 90-day mortality of 14%. This first nationwide Italian pediatric survey shows that the circulation of CPE strains in the pediatric hematology-oncology environment is increasing. Given the mortality rate, which is higher than for other bacterial strains, specific monitoring should be applied and the results should have implications for health-care practice in pediatric hematology-oncology.

  20. Epidemiological characterization of Acinetobacter baumannii bloodstream isolates from a Chinese Burn Institute: A three-year study.

    Science.gov (United States)

    Huang, Guangtao; Yin, Supeng; Xiang, Lijuan; Gong, Yali; Sun, Kedai; Luo, Xiaoqiang; Zhang, Cheng; Yang, Zichen; Deng, Liuyang; Jiang, Bei; Jin, Shouguang; Chen, Jing; Peng, Yizhi

    2016-11-01

    Acinetobacter baumannii infection is a serious threat to burn patients. Bacteremia due to A. baumannii is becoming the most common cause of mortality following burn. However, the epidemiology of A. baumannii causing burn-related bloodstream infections has rarely been reported. We retrospectively collected 81 A. baumannii isolates from the bloodstream of burn patients over a three-year period. Antibiotic susceptibility tests, the prevalence of antibiotic-resistant genes and sequence typing (ST) were conducted to characterize these strains. Most of the isolates showed an extensive drug-resistant phenotype. The resistance frequencies to imipenem and meropenem were 94% and 91%, respectively. The blaOXA-23-like gene, AmpC, IS-AmpC, PER and SIM are the five most prevalent resistant genes, and their prevalence rates are 93% (75/81), 86% (70/81), 73% (59/81), 73% (59/81) and 52% (42/81), respectively. The 81 isolates were grouped into 10 known and 18 unknown ST types, with ST368 (38%) being the most prevalent. Except for ST457 and four new types (STn2, STn6, STn11 and STn14), the remaining 23 ST types belonged to one clonal complex 92, which is most common among clinical isolate in China. The above results indicated that ST368 isolates possessing both the blaOXA-23-like gene and ampC gene were the main culprits of the increasing nosocomial A. baumannii infection in this study. More attention should be paid to monitoring the molecular epidemiology of A. baumannii isolates from burn patients to prevent further distribution. Such information may help clinicians with therapeutic decisions and infection control in the Burns Institute. Copyright © 2016. Published by Elsevier Ltd.

  1. Surveillance of Candida spp bloodstream infections: epidemiological trends and risk factors of death in two Mexican tertiary care hospitals.

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    Dora E Corzo-Leon

    Full Text Available Larger populations at risk, broader use of antibiotics and longer hospital stays have impacted on the incidence of Candida sp. bloodstream infections (CBSI.To determine clinical and epidemiologic characteristics of patients with CBSI in two tertiary care reference medical institutions in Mexico City.Prospective and observational laboratory-based surveillance study conducted from 07/2008 to 06/2010.All patients with CBSI were included. Identification and antifungal susceptibility were performed using CLSI M27-A3 standard procedures. Frequencies, Mann-Whitney U test or T test were used as needed. Risk factors were determined with multivariable analysis and binary logistic regression analysis.CBSI represented 3.8% of nosocomial bloodstream infections. Cumulative incidence was 2.8 per 1000 discharges (incidence rate: 0.38 per 1000 patient-days. C. albicans was the predominant species (46%, followed by C. tropicalis (26%. C. glabrata was isolated from patients with diabetes (50%, and elderly patients. Sixty-four patients (86% received antifungals. Amphotericin-B deoxycholate (AmBD was the most commonly used agent (66%. Overall mortality rate reached 46%, and risk factors for death were APACHE II score ≥ 16 (OR = 6.94, CI95% = 2.34-20.58, p<0.0001, and liver disease (OR = 186.11, CI95% = 7.61-4550.20, p = 0.001. Full susceptibility to fluconazole, AmBD and echinocandins among C. albicans, C. tropicalis, and C. parapsilosis was observed.The cumulative incidence rate in these centers was higher than other reports from tertiary care hospitals from Latin America. Knowledge of local epidemiologic patterns permits the design of more specific strategies for prevention and preemptive therapy of CBSI.

  2. Surveillance of Candida spp Bloodstream Infections: Epidemiological Trends and Risk Factors of Death in Two Mexican Tertiary Care Hospitals

    Science.gov (United States)

    Corzo-Leon, Dora E.; Alvarado-Matute, Tito; Colombo, Arnaldo L.; Cornejo-Juarez, Patricia; Cortes, Jorge; Echevarria, Juan I.; Guzman-Blanco, Manuel; Macias, Alejandro E.; Nucci, Marcio; Ostrosky-Zeichner, Luis; Ponce-de-Leon, Alfredo; Queiroz-Telles, Flavio; Santolaya, Maria E.; Thompson-Moya, Luis; Tiraboschi, Iris N.; Zurita, Jeannete; Sifuentes-Osornio, Jose

    2014-01-01

    Introduction Larger populations at risk, broader use of antibiotics and longer hospital stays have impacted on the incidence of Candida sp. bloodstream infections (CBSI). Objective To determine clinical and epidemiologic characteristics of patients with CBSI in two tertiary care reference medical institutions in Mexico City. Design Prospective and observational laboratory-based surveillance study conducted from 07/2008 to 06/2010. Methods All patients with CBSI were included. Identification and antifungal susceptibility were performed using CLSI M27-A3 standard procedures. Frequencies, Mann-Whitney U test or T test were used as needed. Risk factors were determined with multivariable analysis and binary logistic regression analysis. Results CBSI represented 3.8% of nosocomial bloodstream infections. Cumulative incidence was 2.8 per 1000 discharges (incidence rate: 0.38 per 1000 patient-days). C. albicans was the predominant species (46%), followed by C. tropicalis (26%). C. glabrata was isolated from patients with diabetes (50%), and elderly patients. Sixty-four patients (86%) received antifungals. Amphotericin-B deoxycholate (AmBD) was the most commonly used agent (66%). Overall mortality rate reached 46%, and risk factors for death were APACHE II score ≥16 (OR = 6.94, CI95% = 2.34–20.58, p<0.0001), and liver disease (OR = 186.11, CI95% = 7.61–4550.20, p = 0.001). Full susceptibility to fluconazole, AmBD and echinocandins among C. albicans, C. tropicalis, and C. parapsilosis was observed. Conclusions The cumulative incidence rate in these centers was higher than other reports from tertiary care hospitals from Latin America. Knowledge of local epidemiologic patterns permits the design of more specific strategies for prevention and preemptive therapy of CBSI. PMID:24830654

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

    Science.gov (United States)

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

    2017-04-01

    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 low. An alternative is the use of an antiseptic barrier cap, which cleans the catheter hub by continuous passive disinfection. To compare the effects of antiseptic barrier cap use and manual disinfection on the incidence of CLABSIs. Systematic review and meta-analysis. We systematically searched Embase, Medline Ovid, Web-of-science, CINAHL EBSCO, Cochrane Library, PubMed Publisher and Google Scholar until May 10, 2016. The primary outcome, reduction in CLABSIs per 1000 catheter-days, expressed as an incidence rate ratio (IRR), was analyzed with a random effects meta-analysis. Studies were included if 1) conducted in a hospital setting, 2) used antiseptic barrier caps on hubs of central lines with access to the bloodstream and 3) reported the number of CLABSIs per 1000 catheter-days when using the barrier cap and when using manual disinfection. A total of 1537 articles were identified as potentially relevant and after exclusion of duplicates, 953 articles were screened based on title and abstract; 18 articles were read full text. Eventually, nine studies were included in the systematic review, and seven of these nine in the random effects meta-analysis. The pooled IRR showed that use of the antiseptic barrier cap was effective in reducing CLABSIs (IRR=0.59, 95% CI=0.45-0.77, Pantiseptic barrier cap is associated with a lower incidence CLABSIs and is an intervention worth adding to central-line maintenance bundles. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Bloodstream infections caused by multi-drug resistant Proteus mirabilis: Epidemiology, risk factors and impact of multi-drug resistance.

    Science.gov (United States)

    Korytny, Alexander; Riesenberg, Klaris; Saidel-Odes, Lisa; Schlaeffer, Fransisc; Borer, Abraham

    2016-01-01

    The prevalence of antimicrobial co-resistance among ESBL-producing Enterobactereaceae is extremely high in Israel. Multidrug-resistant Proteus mirabilis strains (MDR-PM), resistant to almost all antibiotic classes have been described. The aim was to determine the risk factors for bloodstream infections caused by MDR-PM and clinical outcomes. A retrospective case-control study. Adult patients with PM bacteremia during 7 years were identified retrospectively and their files reviewed for demographics, underlying diseases, Charlson Comorbidity Index, treatment and outcome. One hundred and eighty patients with PM-bloodstream infection (BSI) were included; 90 cases with MDR-PM and 90 controls with sensitive PM (S-PM). Compared to controls, cases more frequently were from nursing homes, had recurrent hospital admissions in the past year and received antibiotic therapy in the previous 3 months, were bedridden and suffered from peripheral vascular disease and peptic ulcer disease (p < 0.001). Two-thirds of the MDR-PM isolates were ESBL-producers vs 4.4% of S-PM isolates (p < 0.001, OR = 47.6, 95% CI = 15.9-142.6). In-hospital crude mortality rate of patients with MDR-PM BSI was 37.7% vs 23.3% in those with S-PM BSI (p = 0.0359, OR = 2, 95% CI = 1.4-3.81). PM bacteremia in elderly and functionally-dependent patients is likely to be caused by nearly pan-resistant PM strains in the institution; 51.8% of the patients received inappropriate empiric antibiotic treatment. The crude mortality rate of patients with MDR-PM BSI was significantly higher than that of patients with S-PM BSI.

  5. Regional variations in fluoroquinolone non-susceptibility among Escherichia coli bloodstream infections within the Veterans Healthcare Administration

    Directory of Open Access Journals (Sweden)

    Daniel J. Livorsi

    2016-10-01

    Full Text Available Abstract Objectives We sought to define regional variations in fluoroquinolone non-susceptibility (FQ-NS among bloodstream isolates of Escherichia coli across the Veterans Health Administration (VHA in the United States. Methods We analyzed a retrospective cohort of patients managed at 136 VHA hospitals who had a blood culture positive for E.coli between 2003 and 2013. Hospitals were classified based on US Census Divisions, and regional variations in FQ-NS were analyzed. Results Twenty-four thousand five hundred twenty-three unique E.coli bloodstream infections (BSIs were identified between 2003 and 2013. 53.9 % of these were community-acquired, 30.7 % were healthcare-associated, and 15.4 % were hospital-onset BSIs. The proportion of E.coli BSIs with FQ-NS significantly varied across US Census Divisions (p < 0.001. During 2003–2013, the proportion of E.coli BSIs with FQ-NS was highest in the West South-Central Division (32.7 % and lowest in the Mountain Division (20.0 %. Multivariable analysis showed that there were universal secular trends towards higher FQ-NS rates (p < 0.001 with significant variability of slopes across US Census Divisions (p < 0.001. Conclusion There has been a universal increase in FQ-NS among E.coli BSIs within VHA, but the rate of increase has significantly varied across Census Divisions. The reasons for this variability are unclear. These findings reinforce the importance of using local data to develop and update local antibiograms and antibiotic-prescribing guidelines.

  6. 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.

  7. Exploring the Trypanosoma brucei Hsp83 potential as a target for structure guided drug design.

    Directory of Open Access Journals (Sweden)

    Juan Carlos Pizarro

    Full Text Available Human African trypanosomiasis is a neglected parasitic disease that is fatal if untreated. The current drugs available to eliminate the causative agent Trypanosoma brucei have multiple liabilities, including toxicity, increasing problems due to treatment failure and limited efficacy. There are two approaches to discover novel antimicrobial drugs--whole-cell screening and target-based discovery. In the latter case, there is a need to identify and validate novel drug targets in Trypanosoma parasites. The heat shock proteins (Hsp, while best known as cancer targets with a number of drug candidates in clinical development, are a family of emerging targets for infectious diseases. In this paper, we report the exploration of T. brucei Hsp83--a homolog of human Hsp90--as a drug target using multiple biophysical and biochemical techniques. Our approach included the characterization of the chemical sensitivity of the parasitic chaperone against a library of known Hsp90 inhibitors by means of differential scanning fluorimetry (DSF. Several compounds identified by this screening procedure were further studied using isothermal titration calorimetry (ITC and X-ray crystallography, as well as tested in parasite growth inhibitions assays. These experiments led us to the identification of a benzamide derivative compound capable of interacting with TbHsp83 more strongly than with its human homologs and structural rationalization of this selectivity. The results highlight the opportunities created by subtle structural differences to develop new series of compounds to selectively target the Trypanosoma brucei chaperone and effectively kill the sleeping sickness parasite.

  8. Evidence-based measures to prevent central line-associated bloodstream infections: a systematic review.

    Science.gov (United States)

    Perin, Daniele Cristina; Erdmann, Alacoque Lorenzini; Higashi, Giovana Dorneles Callegaro; Sasso, Grace Teresinha Marcon Dal

    2016-09-01

    to identify evidence-based care to prevent CLABSI among adult patients hospitalized in ICUs. systematic review conducted in the following databases: PubMed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf and Cochrane Studies addressing care and maintenance of central venous catheters, published from January 2011 to July 2014 were searched. The 34 studies identified were organized in an instrument and assessed by using the classification provided by the Joanna Briggs Institute. the studies presented care bundles including elements such as hand hygiene and maximal barrier precautions; multidimensional programs and strategies such as impregnated catheters and bandages and the involvement of facilities in and commitment of staff to preventing infections. care bundles coupled with education and the commitment of both staff and institutions is a strategy that can contribute to decreased rates of central line-associated bloodstream infections among adult patients hospitalized in intensive care units. identificar evidências de cuidados para prevenção de infecção de corrente sanguínea relacionada a cateter venoso central em pacientes adultos em Unidades de Terapia Intensiva. revisão Sistemática realizada por meio de busca nas bases de dados Pubmed, Scopus, Cinahl, Web of Science, Lilacs, Bdenf e Cochrane. Foram buscadas pesquisas com cuidados com a cateterização e manutenção do cateter venoso central, publicados de janeiro de 2011 a julho de 2014. Os 34 estudos incluídos foram organizados em um instrumento e avaliados por meio da classificação do The Joanna Briggs Institute. os estudos apresentaram bundles de cuidados com elementos como a higiene das mãos e precauções máximas de barreira; programas multidimensionais e estratégias como cateteres e curativos impregnados e o envolvimento da instituição e engajamento da equipe nos esforços para prevenção de infecção. os cuidados no formato de bundles aliados com a educação e engajamento da equipe e

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Stomoxys calcitrans as possible vector of Trypanosoma evansi among camels in an affected area of the Canary Islands, Spain

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    Noé Francisco Rodríguez

    2014-07-01

    Full Text Available Introduction Trypanosoma evansi was first identified in the Canary Islands in 1997, and is still present in a small area of the Archipelago. To date, the disease has exclusively affected camel herds, and has not been detected in any other animal hosts. However potential vectors of Trypanosoma evansi must be identified. Methods One Nzi trap was placed on a camel farm located in the infected area for a period of one year. Results Two thousand five hundred and five insects were trapped, of which Stomoxys calcitrans was the sole hematophagous vector captured. Conclusions Stomoxys calcitrans could be exclusively responsible for the transmission of Trypanosoma evansi among camels in the surveyed area, as other species do not seem to be infected by S. calcitrans in the presence of camels.

  11. Estudo do papel funcional da cisteína sintase e da cistationina B-sintase na resposta ao estresse oxidativo e nitrosativo em leishmania (viannia) braziliensis, trypanosoma rangeli e trypanosoma cruzi

    OpenAIRE

    Romero Calderon, Ibeth Cristina

    2014-01-01

    Tese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Biotecnologia e Biociências, Florianópolis, 2014 Leishmania (Viannia) braziliensis, Trypanosoma rangeli e o Trypanosoma cruzi são parasitos hemoflagelados pertencentes à Ordem Kinetoplastida, família Trypanosomatidae, capazes de infectar insetos, animais silvestres e domésticos, assim como o homem. Durante seu ciclo de vida, estes parasitos são expostos a uma grande quanti...

  12. (EOI) Form

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dorine Odongo

    COLLABORATING TECHNICAL AGENCIES: EXPRESSION OF INTEREST FORM. • Please read the information provided about the initiative and the eligibility requirements in the Prospectus before completing this application form. • Ensure all the sections of the form are accurately completed and saved in PDF format.

  13. Modular forms

    NARCIS (Netherlands)

    Edixhoven, B.; van der Geer, G.; Moonen, B.; Edixhoven, B.; van der Geer, G.; Moonen, B.

    2008-01-01

    Modular forms are functions with an enormous amount of symmetry that play a central role in number theory, connecting it with analysis and geometry. They have played a prominent role in mathematics since the 19th century and their study continues to flourish today. Modular forms formed the

  14. 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...

  15. Catheter-free Period Over 2 Days Is Associated with Better Outcome in Catheter-related Bloodstream Infection due to Candida

    OpenAIRE

    Matsuo, Takahiro; Mori, Nobuyoshi; Hoshino, Eri; Sakurai, Aki; Furukawa, Keiichi

    2017-01-01

    Abstract Background Regardless of active antifungal drugs, mortality of candidemia remains high. Although it is well-known that central venous catheter (CVC) is one of the most important risk factors of candidemia and should be removed immediately, little is known about optimal timing of CVC replacement after removal. Here, we analyzed contributing risk factors associated with 30-day mortality for catheter-related bloodstream infection (CRBSI) due to candida and optimal timing of CVC replacem...

  16. Procalcitonin as a diagnostic biomarker for septic shock and bloodstream infection in burn patients from the Formosa Fun Coast dust explosion

    Directory of Open Access Journals (Sweden)

    Rui-Xin Wu

    2017-12-01

    Full Text Available Background/Purpose: Infection is the most common cause of death following burn injury. The study was conducted to compare the diagnostic value of serum procalcitonin (PCT with the other current benchmarks as early predictors of septic shock and bloodstream infection in burn patients. Methods: We included 24 patients admitted to the Burn Unit of a medical center from June 2015 to December 2015 from the Formosa Fun Coast dust explosion. We categorized all patients at initial admission into either sepsis or septic shock groups. Laboratory tests including the worst PCT and C-reactive protein (CRP levels, platelet (PLT, and white blood cell (WBC count were performed at <48 h after admission. Patients were also classified in two groups with subsequent bacteremia and non-bacteremia groups during hospitalization. Results: Significantly higher PCT levels were observed among participants with septic shock compared to those with sepsis (47.19 vs. 1.18 ng/mL, respectively; p < 0.001. Patients with bacteremia had significantly elevated PCT levels compared to patients without bacteremia (29.54 versus 1.81 ng/mL, respectively, p < 0.05. No significant differences were found in CRP levels, PLT, and WBC count between the two groups. PCT levels showed reasonable discriminative power (cut-off: 5.12 ng/mL; p = 0.01 in predicting of bloodstream infection in burn patients and the area under receiver operating curves was 0.92. Conclusions: PCT levels can be helpful in determining the septic shock and bloodstream infection in burn patients but CRP levels, PLT, and WBC count were of little diagnostic value. Keywords: Procalcitonin, Septic shock, Bloodstream infection, Burn patient, Formosa fun coast dust explosion

  17. Timing of positive blood samples does not differentiate pathogens causing healthcare-associated from community-acquired bloodstream infections in children in England: a linked retrospective cohort study

    OpenAIRE

    HENDERSON, K. L.; M?LLER-PEBODY, B.; WADE, A.; SHARLAND, M.; MINAJI, M.; JOHNSON, A. P.; GILBERT, R

    2014-01-01

    SUMMARY Paediatricians recognize that using the time-dependent community-acquired vs. hospital-acquired bloodstream infection (BSI) dichotomy to guide empirical treatment no longer distinguishes between causative pathogens due to the emergence of healthcare-associated BSIs. However, paediatric epidemiological evidence of the aetiology of BSIs in relation to hospital admission in England is lacking. For 12 common BSI-causing pathogens in England, timing of laboratory reports of positive paedia...

  18. Leadership line care rounds: Application of the engage, educate, execute, and evaluate improvement model for the prevention of central line-associated bloodstream infections in children with cancer.

    Science.gov (United States)

    Owings, Angie; Graves, JoBeth; Johnson, Sherry; Gilliam, Craig; Gipson, Mike; Hakim, Hana

    2018-02-01

    To prevent central line-associated bloodstream infections (CLABSIs), leadership line care rounds (LLCRs) used the engage, educate, execute, and evaluate improvement model to audit compliance, identify barriers and opportunities, empower patients and families, and engage leadership. Findings of excellence and improvement opportunities were communicated to unit staff and managers. LLCRs contributed to compliance with CLABSI prevention interventions. Copyright © 2018 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  19. Incidence of bloodstream infections in small bowel transplant recipients receiving selective decontamination of the digestive tract: A single-center experience

    OpenAIRE

    Galloway, David; Danziger-Isakov, Lara; Goldschmidt, Monique; Hemmelgarn, Trina; Courter, Joshua; Nathan, Jaimie D.; Alonso, Maria; Tiao, Greg; Fei, Lin; Kocoshis, Samuel

    2015-01-01

    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, ...

  20. Efecto inmunosupresor de la infección por Trypanosoma musculi (Mastigophora: Trypanosomatidae en la toxoplasmosis experimental Immunosuppressor effect of Trypanosoma musculi (Mastigophora: Trypanosomatidae on experimental toxoplasmosis

    Directory of Open Access Journals (Sweden)

    Loretta Piccolo-Johanning

    2013-06-01

    Full Text Available La prevalencia de infecciones por Toxoplasma gondii en el ser humano es de 5-90% según la zona geográfica; en Costa Rica por ejemplo, la seroprevalencia es de un 58%, por lo que es importante comprender algunos procesos inmunológicos, propios en estas afectaciones parasitarias. Con el objeto de determinar si el Trypanosoma musculi ejerce procesos de inmunosupresión sobre Toxoplasma gondii se realizó un experimento en el que se inocularon ratones Swiss con T. musculi cuatro, cinco, seis y siete días previos a la infección con T. gondii, ocurriendo la inmunosupresión cuando la inoculación con T. musculi fue hecha cuatro días antes. Además, la cantidad de tripomastigotos inoculados no influyó en el proceso. Se probaron tres cepas de T. gondii aisladas de las heces de un gato casero (TFC, de un Leopardus pardalis (TLP, de un Leopardus wiedii y de la carne de un Bos taurus (TBT. La cepa TLP resultó ser muy patógena, matando a los animales en un tiempo corto, independientemente de la inoculación con T. musculi; para las otras cepas se mantuvo el patrón de inmunosupresión en los ratones. Se reporta entonces un modelo experimental de inmunosupresión, aspecto muy en boga en este momento, por su relación con enfermedades que inducen esta condición en el ser humano, especialmente a enfermedades como el cáncer y el SIDA. Este modelo es más fácil de aplicar experimentalmente que el correspondiente con T. lewisi previamente descrito, el cual usa ratas blancas de más difícil manejo que los ratones usados en este estudio.The immunosuppression caused by species of the gender Trypanosoma has been widely documented. The influence over experimental infections with Toxoplasma gondii is evident when using Trypanosoma lewisi, a natural parasite of white rats. We decided to test the effect of Trypanosoma musculi from mice, an organism with very similar biological characteristics to T. lewisi, to see if this trypanosomatid could induce a similar

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

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    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

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

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    Nguyen Phuong Thao

    2014-06-01

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

  3. Subcellular localization of glycolytic enzymes and characterization of intermediary metabolism of Trypanosoma rangeli.

    Science.gov (United States)

    Rondón-Mercado, Rocío; Acosta, Héctor; Cáceres, Ana J; Quiñones, Wilfredo; Concepción, Juan Luis

    2017-09-01

    Trypanosoma rangeli is a hemoflagellate protist that infects wild and domestic mammals as well as humans in Central and South America. Although this parasite is not pathogenic for human, it is being studied because it shares with Trypanosoma cruzi, the etiological agent of Chagas' disease, biological characteristics, geographic distribution, vectors and vertebrate hosts. Several metabolic studies have been performed with T. cruzi epimastigotes, however little is known about the metabolism of T. rangeli. In this work we present the subcellular distribution of the T. rangeli enzymes responsible for the conversion of glucose to pyruvate, as determined by epifluorescense immunomicroscopy and subcellular fractionation involving either selective membrane permeabilization with digitonin or differential and isopycnic centrifugation. We found that in T. rangeli epimastigotes the first six enzymes of the glycolytic pathway, involved in the conversion of glucose to 1,3-bisphosphoglycerate are located within glycosomes, while the last four steps occur in the cytosol. In contrast with T. cruzi, where three isoenzymes (one cytosolic and two glycosomal) of phosphoglycerate kinase are expressed simultaneously, only one enzyme with this activity is detected in T. rangeli epimastigotes, in the cytosol. Consistent with this latter result, we found enzymes involved in auxiliary pathways to glycolysis needed to maintain adenine nucleotide and redox balances within glycosomes such as phosphoenolpyruvate carboxykinase, malate dehydrogenase, fumarate reductase, pyruvate phosphate dikinase and glycerol-3-phosphate dehydrogenase. Glucokinase, galactokinase and the first enzyme of the pentose-phosphate pathway, glucose-6-phosphate dehydrogenase, were also located inside glycosomes. Furthermore, we demonstrate that T. rangeli epimastigotes growing in LIT medium only consume glucose and do not excrete ammonium; moreover, they are unable to survive in partially-depleted glucose medium. The

  4. 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.

  5. The capybara (Hydrochoerus hydrochaeris) as a reservoir host for Trypanosoma evansi.

    Science.gov (United States)

    Morales, G A; Wells, E A; Angel, D

    1976-10-01

    Discovery of two ill horses and three dogs naturally infected with Trypanosoma evansi near an experimental station in the Eastern Plains of Colombia led to a search for reservoir hosts of the parasite. Infection was detected in 8/33 healthy capybaras (Hydrochoerus hydrochaeris), none of the remaining 14 horses, and none of 32 Zebu cattle (Bos indicus), 18 paca (Cuniculus paca) and 20 spiny rats (Proechimys sp.). Contrary to common opinion, the results indicated a carrier state in the capybara. Diagnosis was based on morphology, behaviour in albino rats, and pathogenicity and host range in domestic animals.

  6. 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...

  7. Sialoglycoconjugates in Trypanosoma cruzi-host cell interaction: possible biological model - a review

    Directory of Open Access Journals (Sweden)

    Alane Beatriz Vermelho

    1994-03-01

    Full Text Available A number of glycoconjugates, including glycolipids and glycoproteins, participate in the process of host-cell invasion by Trypanosoma cruzi and one of the most important carbohydrates involved on this interaction is sialic acid. It is known that parasite trans-sialidase participates with sialic acid in a coordinated fashion in the initial stages of invasion. Given the importance of these sialogycoconjugates, this review sets out various possible biological models for the interaction between the parasite and mammalian cells that possess a sialylated receptor/ligand system.

  8. A haptoglobin-hemoglobin receptor conveys innate immunity to Trypanosoma brucei in humans

    DEFF Research Database (Denmark)

    Vanhollebeke, Benoit; De Muylder, Géraldine; Nielsen, Marianne J

    2008-01-01

    The protozoan parasite Trypanosoma brucei is lysed by apolipoprotein L-I, a component of human high-density lipoprotein (HDL) particles that are also characterized by the presence of haptoglobin-related protein. We report that this process is mediated by a parasite glycoprotein receptor, which...... binds the haptoglobin-hemoglobin complex with high affinity for the uptake and incorporation of heme into intracellular hemoproteins. In mice, this receptor was required for optimal parasite growth and the resistance of parasites to the oxidative burst by host macrophages. In humans, the trypanosome...... immunity against the parasite....

  9. Metabolic reprogramming during the Trypanosoma brucei life cycle [version 2; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Terry K. Smith

    2017-05-01

    Full Text Available Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

  10. Metabolic reprogramming during the Trypanosoma brucei life cycle [version 1; referees: 4 approved

    Directory of Open Access Journals (Sweden)

    Terry K. Smith

    2017-05-01

    Full Text Available Cellular metabolic activity is a highly complex, dynamic, regulated process that is influenced by numerous factors, including extracellular environmental signals, nutrient availability and the physiological and developmental status of the cell. The causative agent of sleeping sickness, Trypanosoma brucei, is an exclusively extracellular protozoan parasite that encounters very different extracellular environments during its life cycle within the mammalian host and tsetse fly insect vector. In order to meet these challenges, there are significant alterations in the major energetic and metabolic pathways of these highly adaptable parasites. This review highlights some of these metabolic changes in this early divergent eukaryotic model organism.

  11. Studies on the virulence and attenuation of Trypanosoma cruzi using immunodeficient animals

    Directory of Open Access Journals (Sweden)

    Basombrío Miguel Ángel

    2000-01-01

    Full Text Available Tissue invasion and pathology by Trypanosoma cruzi result from an interaction between parasite virulence and host immunity. Successive in vivo generations of the parasite select populations with increasing ability to invade the host. Conversely, prolonged in vitro selection of the parasite produces attenuated sublines with low infectivity for mammals. One such subline (TCC clone has been extensively used in our laboratory as experimental vaccine and tested in comparative experiments with its virulent ancestor (TUL. The experiments here reviewed aimed at the use of immunodeficient mice for testing the infectivity of TCC parasites. It has not been possible to obtain virulent, revertant sublines by prolonged passaged in such mice.

  12. Marker discovery in Trypanosoma vivax through GSS and comparative analysis. Preliminary data and perspectives

    International Nuclear Information System (INIS)

    Davila, A.M.R.; Guerreiro, L.T.A.; Souza, S.S.

    2005-01-01

    Trypanosoma vivax is a haemoparasite affecting the livestock industry in South America and Africa. Despite the high economic relevance of the disease caused by T. vivax, little work has been done on its molecular characterization, in contrast with human trypanosomes, such as T. brucei and T. cruzi. The present study reports the construction of a semi-normalized genomic library and the sequencing of 160 Genome Sequence Survey (GSS) ends of T. vivax. The analyses of this preliminary data show that this simple and rapid approach worked well to generate some potential new markers for this species. (author)

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

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    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.

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

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    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  16. 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...

  17. 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...

  18. Surveillance of bloodstream infections in pediatric cancer centers – what have we learned and how do we move on?

    Directory of Open Access Journals (Sweden)

    Simon, Arne

    2016-05-01

    Full Text Available Pediatric patients receiving conventional chemotherapy for malignant disease face an increased risk of bloodstream infection (BSI. Since BSI may represent an acute life-threatening event in patients with profound immunosuppression, and show further negative impact on quality of life and anticancer treatment, the prevention of BSI is of paramount importance to improve and guarantee patients’ safety during intensive treatment. The great majority of all pediatric cancer patients (about 85% have a long-term central venous access catheter in use (type Broviac or Port; CVAD. Referring to the current surveillance definitions a significant proportion of all BSI in pediatric patients with febrile neutropenia is categorized as CVAD- BSI. This state of the art review summarizes the epidemiology and the distinct pathogen profile of BSI in pediatric cancer patients from the perspective of infection surveillance. Problems in executing the current surveillance definition in this patient population are discussed and a new concept for the surveillance of BSI in pediatric cancer patients is outlined.

  19. Characterization of Third-Generation Cephalosporin-Resistant Escherichia coli from Bloodstream Infections in Denmark

    DEFF Research Database (Denmark)

    Hansen, Frank; Olsen, Stefan S; Heltberg, Ole

    2014-01-01

    The aim of the study was to investigate the molecular epidemiology of 87 third-generation cephalosporin-resistant Escherichia coli (3GC-R Ec) from bloodstream infections in Denmark from 2009. Sixty-eight of the 87 isolates were extended-spectrum beta-lactamase (ESBL) producers, whereas 17 isolates...... featured AmpC mutations only (without a coexpressed ESBL enzyme) and 2 isolates were producing CMY-22. The majority (82%) of the ESBL-producing isolates in our study were CTX-M-15 producers and primarily belonged to phylogroup B2 (54.4%) or D (23.5%). Further, one of the two CMY-22-producing isolates...... belonged to B2, whereas only few of the other AmpCs isolates belonged to B2 and D. Pulsed-field gel electrophoresis revealed that both clonal and nonclonal spread of 3GC-R Ec occurred. ST131 was detected in 50% of ESBL-producing isolates. The remaining ESBL-producing isolates belonged to 17 other sequence...

  20. Implementation of central line-associated bloodstream infection prevention bundles in a surgical intensive care unit using peer tutoring.

    Science.gov (United States)

    Park, Sang-Won; Ko, Suhui; An, Hye-Sun; Bang, Ji Hwan; Chung, Woo-Young

    2017-01-01

    Central line-associated bloodstream infections (CLABSIs) can be prevented through well-coordinated, multifaceted programs. However, implementation of CLABSI prevention programs requires individualized strategies for different institutional situations, and the best strategy in resource-limited settings is uncertain. Peer tutoring may be an efficient and effective method that is applicable in such settings. A prospective intervention was performed to reduce CLABSIs in a surgical intensive care unit (SICU) at a tertiary hospital. The core interventions consisted of implementation of insertion and maintenance bundles for CLABSI prevention. The overall interventions were guided and coordinated by active educational programs using peer tutoring. The CLABSI rates were compared for 9 months pre-intervention, 6 months during the intervention and 9 months post-intervention. The CLABSI rate was further observed for three years after the intervention. The rate of CLABSIs per 1000 catheter-days decreased from 6.9 infections in the pre-intervention period to 2.4 and 1.8 in the intervention (6 m; P  = 0.102) and post-intervention (9 m; P  = 0.036) periods, respectively. A regression model showed a significantly decreasing trend in the infection rate from the pre-intervention period ( P  tutoring in a resource-limited setting was useful and effectively reduced CLABSIs. However, maintaining the reduced CLABSI rate will require further strategies.

  1. A Web-Based, Hospital-Wide Health Care-Associated Bloodstream Infection Surveillance and Classification System: Development and Evaluation.

    Science.gov (United States)

    Tseng, Yi-Ju; Wu, Jung-Hsuan; Lin, Hui-Chi; Chen, Ming-Yuan; Ping, Xiao-Ou; Sun, Chun-Chuan; Shang, Rung-Ji; Sheng, Wang-Huei; Chen, Yee-Chun; Lai, Feipei; Chang, Shan-Chwen

    2015-09-21

    Surveillance of health care-associated infections is an essential component of infection prevention programs, but conventional systems are labor intensive and performance dependent. To develop an automatic surveillance and classification system for health care-associated bloodstream infection (HABSI), and to evaluate its performance by comparing it with a conventional infection control personnel (ICP)-based surveillance system. We developed a Web-based system that was integrated into the medical information system of a 2200-bed teaching hospital in Taiwan. The system automatically detects and classifies HABSIs. In this study, the number of computer-detected HABSIs correlated closely with the number of HABSIs detected by ICP by department (n=20; r=.999 Psystem performed excellently with regard to sensitivity (98.16%), specificity (99.96%), positive predictive value (95.81%), and negative predictive value (99.98%). The system enabled decreasing the delay in confirmation of HABSI cases, on average, by 29 days. This system provides reliable and objective HABSI data for quality indicators, improving the delay caused by a conventional surveillance system.

  2. Changes in healthcare-associated Staphylococcus aureus bloodstream infections after the introduction of a national hand hygiene initiative.

    Science.gov (United States)

    Barnett, Adrian G; Page, Katie; Campbell, Megan; Brain, David; Martin, Elizabeth; Rashleigh-Rolls, Rebecca; Halton, Kate; Hall, Lisa; Jimmieson, Nerina; White, Katherine; Paterson, David; Graves, Nicholas

    2014-08-01

    Interventions that prevent healthcare-associated infection should lead to fewer deaths and shorter hospital stays. Cleaning hands (with soap or alcohol) is an effective way to prevent the transmission of organisms, but rates of compliance with hand hygiene are sometimes disappointingly low. The National Hand Hygiene Initiative in Australia aimed to improve hand hygiene compliance among healthcare workers, with the goal of reducing rates of healthcare-associated infection. We examined whether the introduction of the National Hand Hygiene Initiative was associated with a change in infection rates. Monthly infection rates for healthcare-associated Staphylococcus aureus bloodstream infections were examined in 38 Australian hospitals across 6 states. We used Poisson regression and examined 12 possible patterns of change, with the best fitting pattern chosen using the Akaike information criterion. Monthly bed-days were included to control for increased hospital use over time. The National Hand Hygiene Initiative was associated with a reduction in infection rates in 4 of the 6 states studied. Two states showed an immediate reduction in rates of 17% and 28%, 2 states showed a linear decrease in rates of 8% and 11% per year, and 2 showed no change in infection rates. The intervention was associated with reduced infection rates in most states. The failure in 2 states may have been because those states already had effective initiatives before the national initiative's introduction or because infection rates were already low and could not be further reduced.

  3. High MICs for Vancomycin and Daptomycin and Complicated Catheter-Related Bloodstream Infections with Methicillin-Sensitive Staphylococcus aureus

    Science.gov (United States)

    Viedma, Esther; Chaves, Fernando; Lalueza, Antonio; Fortún, Jesús; Loza, Elena; Pujol, Miquel; Ardanuy, Carmen; Morales, Isabel; de Cueto, Marina; Resino-Foz, Elena; Morales-Cartagena, Alejandra; Rico, Alicia; Romero, María P.; Orellana, María Ángeles; López-Medrano, Francisco; Fernández-Ruiz, Mario; Aguado, José María

    2016-01-01

    We investigated the prognostic role of high MICs for antistaphylococcal agents in patients with methicillin-sensitive Staphylococcus aureus catheter-related bloodstream infection (MSSA CRBSI). We prospectively reviewed 83 episodes from 5 centers in Spain during April 2011–June 2014 that had optimized clinical management and analyzed the relationship between E-test MICs for vancomycin, daptomycin, oxacillin, and linezolid and development of complicated bacteremia by using multivariate analysis. Complicated MSSA CRBSI occurred in 26 (31.3%) patients; MICs for vancomycin and daptomycin were higher in these patients (optimal cutoff values for predictive accuracy = 1.5 μg/mL and 0.5 μg/mL). High MICs for vancomycin (hazard ratio 2.4, 95% CI 1.2–5.5) and daptomycin (hazard ratio 2.4, 95% CI 1.1–5.9) were independent risk factors for development of complicated MSSA CRBSI. Our data suggest that patients with MSSA CRBSI caused by strains that have high MICs for vancomycin or daptomycin are at increased risk for complications. PMID:27192097

  4. Facilitating central line-associated bloodstream infection prevention: a qualitative study comparing perspectives of infection control professionals and frontline staff.

    Science.gov (United States)

    McAlearney, Ann Scheck; Hefner, Jennifer L

    2014-10-01

    Infection control professionals (ICPs) play a critical role in implementing and managing healthcare-associated infection reduction interventions, whereas frontline staff are responsible for delivering direct and ongoing patient care. The objective of our study was to determine if ICPs and frontline staff have different perspectives about the facilitators and challenges of central line-associated bloodstream infection (CLABSI) prevention program success. We conducted key informant interviews at 8 hospitals that participated in the Agency for Healthcare Research and Quality CLABSI prevention initiative called "On the CUSP: Stop BSI." We analyzed interview data from 50 frontline nurses and 26 ICPs to identify common themes related to program facilitators and challenges. We identified 4 facilitators of CLABSI program success: education, leadership, data, and consistency. We also identified 3 common challenges: lack of resources, competing priorities, and physician resistance. However, the perspective of ICPs and frontline nurses differed. Whereas ICPs tended to focus on general descriptions, frontline staff noted program specifics and often discussed concrete examples. Our results suggest that ICPs need to take into account the perspectives of staff nurses when implementing infection control and broader quality improvement initiatives. Further, the deliberate inclusion of frontline staff in the implementation of these programs may be critical to program success. Copyright © 2014 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  5. Prevalence, virulence factors and antifungal susceptibility of Candida spp. isolated from bloodstream infections in a tertiary care hospital in Brazil.

    Science.gov (United States)

    Canela, Heliara Maria Spina; Cardoso, Bárbara; Vitali, Lucia Helena; Coelho, Harnoldo Colares; Martinez, Roberto; Ferreira, Márcia Eliana da Silva

    2018-01-01

    Candida spp. are responsible for 80% of all systemic fungal infections and are associated with high mortality rates. This study characterised 79 bloodstream isolates of C. albicans, C. glabrata, C. orthopsilosis, C. parapsilosis and C. tropicalis from patients in a Brazilian hospital. The susceptibility to amphotericin B, caspofungin, fluconazole and voriconazole was determined; virulence factor production was assessed based on haemolysin, phospholipase and proteinase activities, and the patients' clinical characteristics were analysed. C. albicans was the predominant species (44%), followed by C. glabrata (19%), C. tropicalis (19%), C. parapsilosis (14%) and C. orthopsilosis (4%). The candidemia incidence was 1.52 per 1000 admissions, and the crude mortality rate was 52%. One C. albicans isolate was resistant to fluconazole and voriconazole. Moreover, 20.2%, 2.5% and 3.8% of the isolates exhibited dose-dependent susceptibility to fluconazole, voriconazole and caspofungin, respectively. In conclusion, although the C. glabrata incidence was higher than that usually described in Brazil, its increase was previously observed in studies conducted worldwide. Furthermore, the azole resistance of the C. albicans isolate could be due to previous exposure to these antifungals. These results highlight the importance of epidemiological studies and will facilitate an improved understanding of candidemia in the studied hospital. © 2017 Blackwell Verlag GmbH.

  6. The Antibiotic Resistance Profiles of Bacterial Strains Isolated from Patients with Hospital-Acquired Bloodstream and Urinary Tract Infections

    Directory of Open Access Journals (Sweden)

    Hamed Ghadiri

    2012-01-01

    Full Text Available Treatment of nosocomial infections is becoming difficult due to the increasing trend of antibiotics resistance. Current knowledge on antibiotic resistance pattern is essential for appropriate therapy. We aimed to evaluate antibiotic resistance profiles in nosocomial bloodstream and urinary tract pathogens. A total of 129 blood stream and 300 urinary tract positive samples were obtained from patients referring to Besat hospital over a two-year period (2009 and 2010. Antibiotic sensitivity was ascertained using the Kirby-Bauer disk diffusion technique according to CLSI guidelines. Patient's data such as gender and age were recorded. The ratio of gram-negative to gram-positive bacteria in BSIs was 1.6 : 1. The most prevalent BSI pathogen was Coagulase-Negative Staphylococci (CoNS. The highest resistance rate of CoNS was against penicillin (91.1% followed by ampicillin (75.6%, and the lowest rate was against vancomycin (4.4%. Escherichia coli was the most prevalent pathogen isolated from urinary tract infections (UTIs. Ratio of gram-negative to gram-positive bacteria was 3.2 : 1. The highest resistance rate of E. coli isolates was against nalidixic acid (57.7%. The present study showed that CoNS and E. coli are the most common causative agents of nosocomial BSIs and UTIs, and control of infection needs to be addressed in both antibiotic prescription and general hygiene.

  7. In vitro activity of tigecycline and colistin against A. baumannii clinical bloodstream isolates during an 8-year period.

    Science.gov (United States)

    Spiliopoulou, Anastasia; Jelastopulu, Eleni; Vamvakopoulou, Sofia; Bartzavali, Christina; Kolonitsiou, Fevronia; Anastassiou, Evangelos D; Christofidou, Myrto

    2015-10-01

    Acinetobacter baumannii has emerged as an important and problematic pathogen causing bloodstream infections (BSI) in hospitalized patients. Results of an 8-year period from a university hospital are presented. Identification of A. baumannii was performed by Gram-negative BD BBL Crystal ID and VITEK(®)2 system, whereas, susceptibility testing by VITEK2, Kirby-Bauer disc system, and Etest strips. Interpretation of results was based on CLSI criteria and, regarding tigecycline, Food and Drug Administration (FDA) criteria. Between 2006 and 2013, 441 among 7088 BSI cases were attributed to A. baumannii. Of all isolates, 92·1% were resistant to more than three classes of antibiotics and 79·4% were resistant to all but one or two categories of antimicrobials. Resistance to ampicillin-sulbactam, meropenem, gentamicin, ciprofloxacin, minocycline, and tigecycline increased during the study period (P<0·05). Although tigecycline resistance was low during the first 4 years of the study (25·5%), it increased up to 66·5% during 2010-2013. No isolate was colistin resistant.

  8. Surveillance of bloodstream infections in pediatric cancer centers – what have we learned and how do we move on?

    Science.gov (United States)

    Simon, Arne; Furtwängler, Rhoikos; Graf, Norbert; Laws, Hans Jürgen; Voigt, Sebastian; Piening, Brar; Geffers, Christine; Agyeman, Philipp; Ammann, Roland A.

    2016-01-01

    Pediatric patients receiving conventional chemotherapy for malignant disease face an increased risk of bloodstream infection (BSI). Since BSI may represent an acute life-threatening event in patients with profound immunosuppression, and show further negative impact on quality of life and anticancer treatment, the prevention of BSI is of paramount importance to improve and guarantee patients’ safety during intensive treatment. The great majority of all pediatric cancer patients (about 85%) have a long-term central venous access catheter in use (type Broviac or Port; CVAD). Referring to the current surveillance definitions a significant proportion of all BSI in pediatric patients with febrile neutropenia is categorized as CVAD-associated BSI. This state of the art review summarizes the epidemiology and the distinct pathogen profile of BSI in pediatric cancer patients from the perspective of infection surveillance. Problems in executing the current surveillance definition in this patient population are discussed and a new concept for the surveillance of BSI in pediatric cancer patients is outlined. PMID:27274442

  9. POLYCLONAL OUTBREAK OF BLOODSTREAM INFECTIONS CAUSED BY Burkholderia cepacia COMPLEX IN HEMATOLOGY AND BONE MARROW TRANSPLANT OUTPATIENT UNITS

    Directory of Open Access Journals (Sweden)

    Icaro Boszczowski

    2014-01-01

    Full Text Available Aim: The objective was to describe an outbreak of bloodstream infections by Burkholderia cepacia complex (Bcc in bone marrow transplant and hematology outpatients. Methods: On February 15, 2008 a Bcc outbreak was suspected. 24 cases were identified. Demographic and clinical data were evaluated. Environment and healthcare workers' (HCW hands were cultured. Species were determined and typed. Reinforcement of hand hygiene, central venous catheter (CVC care, infusion therapy, and maintenance of laminar flow cabinet were undertaken. 16 different HCWs had cared for the CVCs. Multi-dose heparin and saline were prepared on counter common to both units. Findings: 14 patients had B. multivorans (one patient had also B. cenopacia, six non-multivorans Bcc and one did not belong to Bcc. Clone A B. multivorans occurred in 12 patients (from Hematology; in 10 their CVC had been used on February 11/12. Environmental and HCW cultures were negative. All patients were treated with meropenem, and ceftazidime lock-therapy. Eight patients (30% were hospitalized. No deaths occurred. After control measures (multidose vial for single patient; CVC lock with ceftazidime; cleaning of laminar flow cabinet; hand hygiene improvement; use of cabinet to store prepared medication, no new cases occurred. Conclusions: This polyclonal outbreak may be explained by a common source containing multiple species of Bcc, maybe the laminar flow cabinet common to both units. There may have been contamination by B. multivorans (clone A of multi-dose vials.

  10. Nanomechanical sensor applied to blood culture pellets: a fast approach to determine the antibiotic susceptibility against agents of bloodstream infections.

    Science.gov (United States)

    Stupar, P; Opota, O; Longo, G; Prod'hom, G; Dietler, G; Greub, G; Kasas, S

    2017-06-01

    The management of bloodstream infection, a life-threatening disease, largely relies on early detection of infecting microorganisms and accurate determination of their antibiotic susceptibility to reduce both mortality and morbidity. Recently we developed a new technique based on atomic force microscopy capable of detecting movements of biologic samples at the nanoscale. Such sensor is able to monitor the response of bacteria to antibiotic's pressure, allowing a fast and versatile susceptibility test. Furthermore, rapid preparation of a bacterial pellet from a positive blood culture can improve downstream characterization of the recovered pathogen as a result of the increased bacterial concentration obtained. Using artificially inoculated blood cultures, we combined these two innovative procedures and validated them in double-blind experiments to determine the susceptibility and resistance of Escherichia coli strains (ATCC 25933 as susceptible and a characterized clinical isolate as resistant strain) towards a selection of antibiotics commonly used in clinical settings. On the basis of the variance of the sensor movements, we were able to positively discriminate the resistant from the susceptible E. coli strains in 16 of 17 blindly investigated cases. Furthermore, we defined a variance change threshold of 60% that discriminates susceptible from resistant strains. By combining the nanomotion sensor with the rapid preparation method of blood culture pellets, we obtained an innovative, rapid and relatively accurate method for antibiotic susceptibility test directly from positive blood culture bottles, without the need for bacterial subculture. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Rapid and reliable MALDI-TOF mass spectrometry identification of Candida non-albicans isolates from bloodstream infections.

    Science.gov (United States)

    Pulcrano, Giovanna; Iula, Dora Vita; Vollaro, Antonio; Tucci, Alessandra; Cerullo, Monica; Esposito, Matilde; Rossano, Fabio; Catania, Maria Rosaria

    2013-09-01

    Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has recently become an effective instrument for rapid microbiological diagnostics and in particular for identification of micro-organisms directly in a positive blood culture. The aim of the study was to evaluate a collection of 82 stored yeast isolates from bloodstream infection, by MALDI-TOF MS; 21 isolates were identified also directly from positive blood cultures and in the presence of other co-infecting micro-organisms. Of the 82 isolates grown on plates, 64 (76%) were correctly identified by the Vitek II system and 82 (100%) by MALDI-TOF MS; when the two methods gave different results, the isolate was identified by PCR. MALDI-TOF MS was unreliable in identifying two isolates (Candida glabrata and Candida parapsilosis) directly from blood culture; however, direct analysis from positive blood culture samples was fast and effective for the identification of yeast, which is of great importance for early and adequate treatment. © 2013. Published by Elsevier B.V. All rights reserved.

  12. A 12-year review of Staphylococcus aureus bloodstream infections in haemodialysis patients: more work to be done.

    LENUS (Irish Health Repository)

    Fitzgerald, S F

    2012-02-01

    Staphylococcus aureus bloodstream infections (BSI) are a significant cause of morbidity and mortality in haemodialysis patients. This study describes a 12-year retrospective review of S. aureus BSI in a large haemodialysis centre in a tertiary referral hospital. The overall rate of S. aureus BSI was 17.9 per 100 patient-years (range 9.7-36.8). The rate of meticillin-resistant S. aureus (MRSA) BSI was 5.6 per 100 patient-years (range 0.9-13.8). Infective complications occurred in 11% of episodes, the most common being infective endocarditis (7.6%). Ten percent of patients died within 30 days of S. aureus being isolated from blood. Most cases of S. aureus BSI (83%) were related to vascular catheters. The provision of lower-risk vascular access, such as arteriovenous fistulae, and reduced use of intravascular catheters should be priorities in all haemodialysis units. Where alternative vascular access cannot be established, interventions to reduce the risk of catheter-related infections should be implemented to reduce morbidity and mortality in this vulnerable patient group.

  13. A target-based high throughput screen yields Trypanosoma brucei hexokinase small molecule inhibitors with antiparasitic activity.

    Directory of Open Access Journals (Sweden)

    Elizabeth R Sharlow

    2010-04-01

    Full Text Available The parasitic protozoan Trypanosoma brucei utilizes glycolysis exclusively for ATP production during infection of the mammalian host. The first step in this metabolic pathway is mediated by hexokinase (TbHK, an enzyme essential to the parasite that transfers the gamma-phospho of ATP to a hexose. Here we describe the identification and confirmation of novel small molecule inhibitors of bacterially expressed TbHK1, one of two TbHKs expressed by T. brucei, using a high throughput screening assay.Exploiting optimized high throughput screening assay procedures, we interrogated 220,233 unique compounds and identified 239 active compounds from which ten small molecules were further characterized. Computation chemical cluster analyses indicated that six compounds were structurally related while the remaining four compounds were classified as unrelated or singletons. All ten compounds were approximately 20-17,000-fold more potent than lonidamine, a previously identified TbHK1 inhibitor. Seven compounds inhibited T. brucei blood stage form parasite growth (0.03

  14. Membrane cholesterol regulates lysosome-plasma membrane fusion events and modulates Trypanosoma cruzi invasion of host cells.

    Directory of Open Access Journals (Sweden)

    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