Publications by authors named "Eliane Lages-Silva"

51 Publications

IgG Subclass Analysis in Patients with Chagas Disease 4 Years After Benznidazole Treatment.

Acta Parasitol 2021 Jun 11. Epub 2021 Jun 11.

Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro. Uberaba, Minas Gerais, Brazil.

Background: In humans, Trypanosoma cruzi infection is controlled by a complex immune response. Immunoglobulin G (IgG) is important for opsonizing blood trypomastigotes, activating the classic complement pathway, and reducing parasitemia. The trypanocidal activity of benznidazole is recognized, but its effects on the prevention and progression of Chagas disease is not well understood OBJECTIVE: We aimed to evaluate the levels of total IgG and cross-specific IgG subclasses in patients with chronic Chagas disease of different clinical forms before and after 4 years of benznidazole treatment.

Methods: Eight individuals with the indeterminate form and nine with the cardiac form who completed the treatment protocol were evaluated. The levels of total IgG and IgG1, IgG2, IgG3, and IgG4 isotypes were quantified in the serum of each individual using the fluorescent immunosorbent assay. The results are expressed as relative fluorescence unit.

Results: Patients with chronic Chagas disease presented decreased levels of total IgG at 48 months after benznidazole treatment. Increased IgG1 and decreased IgG3 levels were observed in patients with the cardiac form and those with exacerbated clinical forms. In addition, a decrease in the IgG3/IgG1 ratio was observed in individuals with the cardiac form of Chagas disease.

Conclusions: Benznidazole administration in the chronic phase differentially changes IgG subclasses in patients with cardiac and indeterminate forms, and monitoring the IgG3 level may indicate the possible prognosis to the cardiac form or worsening of the already established clinical form.
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http://dx.doi.org/10.1007/s11686-021-00430-3DOI Listing
June 2021

28Sβ Ribosomal Gene Allows Intra and Interspecific Molecular Differentiation.

Vector Borne Zoonotic Dis 2020 02 22;20(2):117-124. Epub 2019 Oct 22.

Centro de Educação Profissional (CEFORES), Universidade Federal do Triângulo Mineiro (UFTM), Uberaba, Brasil.

is an avirulent flagellate protozoan that could mislead correct diagnosis of infection, the causative agent of Chagas' disease, given their high similarity. Besides, presents two genetic groups, whose differentiation is achieved mainly by molecular approaches. In this context, ribosomal DNA (rDNA) is a useful target for intra and interspecific molecular differentiation. Analyzing the rDNA of and comparison with other trypanosomatid species, two highly divergent regions (Trβ1 and Trβ2) within the 28Sβ gene were found. Those regions were amplified and sequenced in KP1(+) and KP1(-) strains of , revealing group-specific polymorphisms useful for intraspecific distinction through restriction fragment length polymorphism technique. Also, amplification of Trβ1 allowed differentiation between and Trβ2 predicted restriction length profile, allowed differentiation between , , , and , increasing the use of Trβ1 and Trβ2 beyond a molecular approach for genotyping, but also as a useful target for trypanosomatid classification.
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http://dx.doi.org/10.1089/vbz.2019.2496DOI Listing
February 2020

T-Cell Immunophenotyping and Cytokine Production Analysis in Patients with Chagas Disease 4 Years after Benznidazole Treatment.

Infect Immun 2019 08 23;87(8). Epub 2019 Jul 23.

Department of Microbiology, Immunology and Parasitology, Federal University of Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.

The major problem with Chagas disease is evolution of the chronic indeterminate form to a progressive cardiac disease. Treatment diminishes parasitemia but not clinical progression, and the immunological features involved are unclear. Here, we studied the clinical course and the immune response in patients with chronic-phase Chagas disease at 48 months after benznidazole treatment. Progression to the cardiac form of Chagas disease or its aggravation was associated with higher antigen-specific production of interferon gamma (IFN-γ) in patients with cardiac Chagas disease than in patients with the indeterminate form. Predominance of IFN-γ production over interleukin-10 (IL-10) production in antigen-specific cultures was associated with cardiac involvement. Significantly higher numbers of antigen-specific T helper 1 cells (T-Bet IFN-γ) and a significantly higher IFN-γ/IL-10 ratio were observed in patients with cardiac Chagas disease than in patients with the indeterminate form. Cardiac damage was associated with higher numbers of T helper cells than cytotoxic T lymphocytes producing IFN-γ. Patients with cardiac Chagas disease had predominant CD25 and CD25 T regulatory (Treg) subpopulations, whereas patients with the indeterminate form manifested a higher relative mean percentage of CD25 Treg subpopulations. These findings suggest that at 48 months after benznidazole treatment, the disease can worsen or progress to the cardiac form. The progression may be related to increased IFN-γ production (mostly from CD4 T cells) relative to IL-10 production and increased Treg percentages. Patients with the indeterminate form of Chagas disease show a more balanced ratio of proinflammatory and anti-inflammatory cytokines.
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http://dx.doi.org/10.1128/IAI.00103-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6652764PMC
August 2019

Evaluation of the multispecies coalescent method to explore intra-Trypanosoma cruzi I relationships and genetic diversity.

Parasitology 2019 07 3;146(8):1063-1074. Epub 2019 May 3.

Grupo de Investigaciones Microbiológicas-UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas,Universidad del Rosario,Bogotá,Colombia.

Chagas Disease is a zoonosis caused by the parasite Trypanosoma cruzi. Several high-resolution markers have subdivided T. cruzi taxon into at least seven lineages or Discrete Typing Units (DTUs) (TcI-TcVI and TcBat). Trypanosoma cruzi I is the most diverse and geographically widespread DTU. Recently a TcI genotype related to domestic cycles was proposed and named as TcIDOM. Herein, we combined traditional markers and housekeeping genes and applied a Multispecies Coalescent method to explore intra-TcI relationships, lineage boundaries and genetic diversity in a random set of isolates and DNA sequences retrieved from Genbank from different countries in the Americas. We found further evidence supporting TcIDOM as an independent and emerging genotype of TcI at least in Colombia and Venezuela. We also found evidence of high phylogenetic incongruence between parasite's gene trees (including introgression) and embedded species trees, and a lack of genetic structure among geography and hosts, illustrating the complex dynamics and epidemiology of TcI across the Americas. These findings provide novel insights into T. cruzi systematics and epidemiology and support the need to assess parasite diversity and lineage boundaries through hypothesis testing using different approaches to those traditionally employed, including the Bayesian Multispecies coalescent method.
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http://dx.doi.org/10.1017/S0031182019000428DOI Listing
July 2019

Identification of bat trypanosomes from Minas Gerais state, Brazil, based on 18S rDNA and Cathepsin-L-like targets.

Parasitol Res 2018 Mar 16;117(3):737-746. Epub 2018 Jan 16.

Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.

Several bat species can be infected by trypanosomes, but there is not much information about which of these parasites infect bats from Triângulo Mineiro and Alto Paranaíba, Minas Gerais state, Brazil, a formerly endemic region for Trypanosoma cruzi, the causative agent of Chagas disease. The aim of this study was to describe, characterize, and identify the presence of trypanosomes in bats. The captured bats (448) belong to four families and to 19 different species. Of those, 37 bats were found to be positive for trypanosomes by microhematocrit, (infection rate 8.3%) and 27 were positive after hemoculture analysis. Initially, the isolates were identified by PCR (18S rDNA, 24Sα rDNA, spliced leader, COII RFLP-PCR) using primers originally designed for T. cruzi. PCRs (18S rDNA, 24Sα rDNA) showed compatible bands for TcI, whereas COII RFLP-PCR showed a similar pattern associated to TcII. However, there was no DNA amplification using spliced leader as a target, revealing a discrepancy between the results. Phylogenetic analysis of Cathepsin L-like and 18S rDNA sequences proved that 15 of the isolates corresponded to Trypanosoma cruzi marinkellei and one to Trypanosoma dionisii. These results revealed that the diversity of trypanosome species in a region considered endemic for Chagas disease is greater than previous descriptions. All this can confirm the necessity of using DNA sequencing approaches in order to determinate trypanosomes species isolated from bats.
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http://dx.doi.org/10.1007/s00436-017-5744-zDOI Listing
March 2018

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

PLoS One 2017 19;12(12):e0189907. Epub 2017 Dec 19.

Departamento de Bioquímica, Farmacologia e Fisiologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Brasil.

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.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0189907PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5736184PMC
January 2018

Leishmania infection in bats from a non-endemic region of Leishmaniasis in Brazil.

Parasitology 2017 Dec 23;144(14):1980-1986. Epub 2017 Aug 23.

Universidade Federal do Triângulo Mineiro,Uberaba,Minas Gerais,Brazil.

Leishmaniasis is a complex of zoonotic diseases caused by parasites of the genus Leishmania, which can develop in domestic as well as wild animals and humans throughout the world. Currently, this disease is spreading in rural and urban areas of non-endemic regions in Brazil. Recently, bats have gained epidemiological significance in leishmaniasis due to its close relationship with human settlements. In this study, we investigated the presence of Leishmania spp. DNA in blood samples from 448 bats belonging to four families representing 20 species that were captured in the Triangulo Mineiro and Alto Paranaiba areas of Minas Gerais State (non-endemic areas for leishmaniasis), Brazil. Leishmania spp. DNA was detected in 8·0% of the blood samples, 41·6% of which were Leishmania infantum, 38·9% Leishmania amazonensis and 19·4% Leishmania braziliensis. No positive correlation was found between Leishmania spp. and bat food source. The species with more infection rates were the insectivorous bats Eumops perotis; 22·2% (4/18) of which tested positive for Leishmania DNA. The presence of Leishmania in the bat blood samples, as observed in this study, represents epidemiological importance due to the absence of Leishmaniasis cases in the region.
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http://dx.doi.org/10.1017/S0031182017001500DOI Listing
December 2017

2 nd Brazilian Consensus on Chagas Disease, 2015.

Rev Soc Bras Med Trop 2016 Dec;49Suppl 1(Suppl 1):3-60

Universidade Estadual de Londrina, Faculdade de Medicina, Londrina-PR, Brasil.

Chagas disease is a neglected chronic condition with a high burden of morbidity and mortality. It has considerable psychological, social, and economic impacts. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on the articulation and strategic contribution of renowned Brazilian experts with knowledge and experience on various aspects of the disease. It is the result of a close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. It is hoped that this document will strengthen the development of integrated actions against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research .
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http://dx.doi.org/10.1590/0037-8682-0505-2016DOI Listing
December 2016

[Brazilian Consensus on Chagas Disease, 2015].

Epidemiol Serv Saude 2016 06;25(spe):7-86

Universidade Estadual de Londrina, Faculdade de Medicina, Londrina-PR, Brasil.

Chagas disease is a neglected chronic condition that presents high morbidity and mortality burden, with considerable psychological, social, and economic impact. The disease represents a significant public health issue in Brazil, with different regional patterns. This document presents the evidence that resulted in the Brazilian Consensus on Chagas Disease. The objective was to review and standardize strategies for diagnosis, treatment, prevention, and control of Chagas disease in the country, based on the available scientific evidence. The consensus is based on collaboration and contribution of renowned Brazilian experts with vast knowledge and experience on various aspects of the disease. It is the result of close collaboration between the Brazilian Society of Tropical Medicine and the Ministry of Health. This document shall strengthen the development of integrated control measures against Chagas disease in the country, focusing on epidemiology, management, comprehensive care (including families and communities), communication, information, education, and research.
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http://dx.doi.org/10.5123/S1679-49742016000500002DOI Listing
June 2016

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

Rev Soc Bras Med Trop 2016 May-Jun;49(3):369-72

Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brasil.

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.
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http://dx.doi.org/10.1590/0037-8682-0190-2015DOI Listing
March 2017

The Driving of Immune Response by Th1 Adjuvants in Immunization of Mice with Trypanosoma cruzi marinkellei Elicits a Controversial Infection Control.

Vector Borne Zoonotic Dis 2016 05 9;16(5):317-25. Epub 2016 Mar 9.

2 Department of Microbiology, Immunology and Parasitology, Institute of Biological and Natural Sciences, Federal University of Triângulo Mineiro (UFTM) , Uberaba, Brazil .

In previous studies, we have demonstrated that inoculation with a Trypanosoma cruzi marinkellei (avirulent RM1 strain) was able to reduce parasitemia in mice challenged with T. cruzi, although it was not able to prevent histopathological lesions. Th1 response stimulation by immunization is necessary for T. cruzi infection control, but the resistance is also dependent on immunoregulatory mechanisms, which can be induced by adjuvants. Thus, we evaluated whether inoculation of T. cruzi marinkellei associated with administration of different adjuvants would be capable of inducing different patterns of immune response to maximize the immune response against T. cruzi (virulent Romildo strain) infection. Two hundred eighty nonisogenic mice were divided into 14 groups according to the immunization scheme and the subsequent challenge with virulent Romildo T. cruzi strain. Nonimmunized groups and animals inoculated without adjuvants were also included. Immune protection was not observed with Th2 adjuvants (incomplete Freund's adjuvant [IFA] and Alum) due to high parasitemia. Th1/Th2-polarizing adjuvants also did not induce immune protection because inulin was unable to maintain survival, and immune-stimulating complexes induced intense inflammatory processes. Animals sensitized with RM1 strain without adjuvants were able to reduce parasitemia, increase survival, and protect against severe histological lesions, followed by adequate cytokine stimulation. Finally, our results demonstrate that the early and balanced IFN-γ production becomes critical to promote protection and that Th1 adjuvant elicited a controversial infection control due to increased histopathological damage. Therefore, the host's immunomodulation remains one of the most important challenges in the research for effective protection against T. cruzi infection. Similarly, the identification of protective antigens in the RM1 strain of T. cruzi marinkellei may contribute to further studies on vaccine development against human Chagas disease.
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http://dx.doi.org/10.1089/vbz.2015.1874DOI Listing
May 2016

Analytical Validation of Quantitative Real-Time PCR Methods for Quantification of Trypanosoma cruzi DNA in Blood Samples from Chagas Disease Patients.

J Mol Diagn 2015 Sep;17(5):605-15

Laboratory of Molecular Biology, Universidad Mayor de San Simón, Cochabamba, Bolivia.

An international study was performed by 26 experienced PCR laboratories from 14 countries to assess the performance of duplex quantitative real-time PCR (qPCR) strategies on the basis of TaqMan probes for detection and quantification of parasitic loads in peripheral blood samples from Chagas disease patients. Two methods were studied: Satellite DNA (SatDNA) qPCR and kinetoplastid DNA (kDNA) qPCR. Both methods included an internal amplification control. Reportable range, analytical sensitivity, limits of detection and quantification, and precision were estimated according to international guidelines. In addition, inclusivity and exclusivity were estimated with DNA from stocks representing the different Trypanosoma cruzi discrete typing units and Trypanosoma rangeli and Leishmania spp. Both methods were challenged against 156 blood samples provided by the participant laboratories, including samples from acute and chronic patients with varied clinical findings, infected by oral route or vectorial transmission. kDNA qPCR showed better analytical sensitivity than SatDNA qPCR with limits of detection of 0.23 and 0.70 parasite equivalents/mL, respectively. Analyses of clinical samples revealed a high concordance in terms of sensitivity and parasitic loads determined by both SatDNA and kDNA qPCRs. This effort is a major step toward international validation of qPCR methods for the quantification of T. cruzi DNA in human blood samples, aiming to provide an accurate surrogate biomarker for diagnosis and treatment monitoring for patients with Chagas disease.
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http://dx.doi.org/10.1016/j.jmoldx.2015.04.010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4698797PMC
September 2015

Trypanosoma cruzi DTU TcII presents higher blood parasitism than DTU TcI in an experimental model of mixed infection.

Acta Parasitol 2015 Sep;60(3):435-41

Trypanosoma cruzi (Tc), the causative agent of Chagas disease, affects millions of people worldwide. One of the major characteristics of T. cruzi is related to its heterogeneity due to the variability of its biological properties, parasite growth rates, infectivity, tissue tropism, morbidity and virulence among different isolates observed during experimental or human infection. Moreover, presence of mixed infections in the same host in endemic areas is a matter of study due to its impact on clinical manifestations and disease progression. In this study, we evaluated the biological behavior of two Tc I strains AQ1-7 (AQ) and MUTUM (MT) and one Tc II strain (JG) during the acute phase of infection, in unique and mixed infections. A patent blood parasitism was detected only in mice inoculated with JG strain . In addition blood parasitism parameters (peak and average blood parasitism) were positively associated when JG and AQ strains were combined. In contrast, a negative association was observed in the JG+MUTUM group. The predominance of TcII strain over TcI strains was highlighted using the LSSP-PCR technique, which was performed in samples from hemoculture. Thus, this study showed important biological differences between different T. cruzi strains and discrete typing units (DTUs) in acute phase. Finally, we observed that blood parasitism during early period of infection seems to be more related to DTU than to a specific strain.
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http://dx.doi.org/10.1515/ap-2015-0060DOI Listing
September 2015

Immunomodulation by Trypanosoma cruzi: toward understanding the association of dendritic cells with infecting TcI and TcII populations.

J Immunol Res 2014 13;2014:962047. Epub 2014 Oct 13.

Postgraduate Course of Tropical Medicine and Infectology, Laboratory of Parasitology, Federal University of Triângulo Mineiro, Uberaba, MG, Brazil.

Dendritic cells (DCs) are major immune components, and depending on how these cells are modulated, the protective host immune response changes drastically. Trypanosoma cruzi is a parasite with high genetic variability and modulates DCs by interfering with their capacity for antigen recognition, migration, and maturation. Despite recent efforts, the association between DCs and T. cruzi I (TcI) and TcII populations is unknown. Herein, it was demonstrated that AQ1.7 and MUTUM TcI strains present low rates of invasion of bone marrow-derived DCs, whereas the 1849 and 2369 TcII strains present higher rates. Whereas the four strains similarly induced the expression of PD-L1, the production and expression of IL-10 and TLR-2, respectively, in DCs were differentially increased. The production of TNF-α, IL-12, IL-6, and CCL2 and the expression of CD40, CD80, MHC-II, CCR5, and CCR7 changed depending on the strain. The 2369 strain yielded the most remarkable results because greater invasion correlated with an increase in the levels of anti-inflammatory molecules IL-10 and PD-L1 but not with a change in the levels of TNF-α, MHC-II, or CD40 molecules. These results suggest that T. cruzi strains belonging to different populations have evolved specific evasion strategies that subvert DCs and consequently the host response.
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http://dx.doi.org/10.1155/2014/962047DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4211313PMC
June 2015

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

Rev Soc Bras Med Trop 2014 Sep-Oct;47(5):653-6

Disciplina de Parasitologia, Departamento de Ciências Biológicas, Universidade Federal do Triângulo Mineiro, Uberaba, MG, Brazil.

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.
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http://dx.doi.org/10.1590/0037-8682-0255-2013DOI Listing
July 2015

Effects of cholinergic stimulation with pyridostigmine bromide on chronic chagasic cardiomyopathic mice.

Mediators Inflamm 2014 24;2014:475946. Epub 2014 Aug 24.

Natural and Biological Sciences Institute, Triangulo Mineiro Federal University, Praca Manoel Terra 330, Centro, 38025-015 Uberaba, MG, Brazil.

The aim of the present study was to assess the effects of an anticholinesterase agent, pyridostigmine bromide (Pyrido), on experimental chronic Chagas heart disease in mice. To this end, male C57BL/6J mice noninfected (control:Con) or chronically infected (5 months) with Trypanosoma cruzi (chagasic:Chg) were treated or not (NT) with Pyrido for one month. At the end of this period, electrocardiogram (ECG); cardiac autonomic function; heart histopathology; serum cytokines; and the presence of blood and tissue parasites by means of immunohistochemistry and PCR were assessed. In NT-Chg mice, significant changes in the electrocardiographic, autonomic, and cardiac histopathological profiles were observed confirming a chronic inflammatory response. Treatment with Pyrido in Chagasic mice caused a significant reduction of myocardial inflammatory infiltration, fibrosis, and hypertrophy, which was accompanied by a decrease in serum levels of IFNγ with no change in IL-10 levels, suggesting a shift of immune response toward an anti-inflammatory profile. Lower nondifferent numbers of parasite DNA copies were observed in both treated and nontreated chagasic mice. In conclusion, our findings confirm the marked neuroimmunomodulatory role played by the parasympathetic autonomic nervous system in the evolution of the inflammatory-immune response to T. cruzi during experimental chronic Chagas heart disease in mice.
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http://dx.doi.org/10.1155/2014/475946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4158292PMC
May 2015

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

Parasitol Res 2014 Jun 12;113(6):2199-207. Epub 2014 Apr 12.

Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Avenida Frei Paulino, 30, Bairro Abadia, Uberaba, Minas Gerais, 38025-180, Brazil.

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.
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http://dx.doi.org/10.1007/s00436-014-3872-2DOI Listing
June 2014

First evidence of genetic intraspecific variability and occurrence of Entamoeba gingivalis in HIV(+)/AIDS.

PLoS One 2013 20;8(12):e82864. Epub 2013 Dec 20.

Infectious and Parasitic Diseases Unit and Parasitology Unit, Federal University of Triangulo Mineiro, Uberaba, Minas Gerais, Brazil.

Entamoeba gingivalis is considered an oral commensal but demonstrates a pathogenic potential associated with periodontal disease in immunocompromised individuals. Therefore, this study evaluated the occurrence, opportunistic conditions, and intraspecific genetic variability of E. gingivalis in HIV(+)/AIDS patients. Entamoeba gingivalis was studied using fresh examination (FE), culture, and PCR from bacterial plaque samples collected from 82 HIV(+)/AIDS patients. Genetic characterization of the lower ribosomal subunit of region 18S (18S-SSU rRNA) was conducted in 9 positive samples using low-stringency single specific primer PCR (LSSP-PCR) and sequencing analysis. Entamoeba gingivalis was detected in 63.4% (52/82) of the samples. No association was detected between the presence of E. gingivalis and the CD4(+) lymphocyte count (≤200 cells/mm(3) (p = 0.912) or viral load (p = 0.429). The LSSP-PCR results helped group E. gingivalis populations into 2 polymorphic groups (68.3% similarity): group I, associated with 63.6% (7/11) of the samples, and group II, associated with 36.4% (4/11) of the samples, which shared 74% and 83.7% similarity and association with C and E isolates from HIV(-) individuals, respectively. Sequencing of 4 samples demonstrated 99% identity with the reference strain ATCC 30927 and also showed 2 divergent clusters, similar to those detected by LSSP-PCR. Opportunistic behavior of E. gingivalis was not detected, which may be related to the use of highly active antiretroviral therapy by all HIV(+)/AIDS patients. The high occurrence of E. gingivalis in these patients can be influenced by multifactorial components not directly related to the CD4(+) lymphocyte counts, such as cholesterol and the oral microbiota host, which could mask the potential opportunistic ability of E. gingivalis. The identification of the 18S SSU-rRNA polymorphism by LSSP-PCR and sequencing analysis provides the first evidence of genetic variability in E. gingivalis isolated from HIV patients.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0082864PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3869735PMC
October 2014

A DTU-dependent blood parasitism and a DTU-independent tissue parasitism during mixed infection of Trypanosoma cruzi in immunosuppressed mice.

Parasitol Res 2014 Jan 1;113(1):375-85. Epub 2013 Nov 1.

Pós Graduação em Ciências Fisiológicas, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil,

Trypanosoma cruzi (Tc) diversity is determined by different biological, genetic, and biochemical markers and has been grouped into six discrete typing units (DTUs) or taxonomic groups (TcI-TcVI). This variability, coupled with natural reinfection or the hosts' immunosuppression, may play an important role in the pathogenesis of Chagas disease. Therefore, we evaluated the blood and tissue parasitism and genetic profile of mice coinfected with the TcII (JG) strain and TcI AQ1-7 (AQ) or MUTUM (MT) strains during the acute and chronic phases of the disease and during immunosuppression. T. cruzi blood populations in mixed infections were clearly associated with the TcII strain during acute and chronic phases or during immunosuppression. However, in tissues, the parasite populations were distributed according to the strain and the stage of infection. TcII populations overlapped TcI strains during the acute phase; in contrast, during chronic phase, both TcI strains were more prevalent than the TcII strain. The immunosuppression induced selective exacerbation of parasite populations, leading to reactivation of the TcII strain when associated with the AQ, but not with MT strain. Thus, a differential distribution of T. cruzi populations in blood and tissues with overlapping according to the stage of infection and strain used was observed. Blood parasitism was associated with the DTU TcII and tissue parasitism with a specific parasite strain and not with DTUs. Finally, to our knowledge, this is the first study to analyze subpatent blood parasitism and to simultaneously identify different T. cruzi populations in tissues and blood.
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http://dx.doi.org/10.1007/s00436-013-3665-zDOI Listing
January 2014

Gene identification and comparative molecular modeling of a Trypanosoma rangeli major surface protease.

J Mol Model 2013 Aug 13;19(8):3053-64. Epub 2013 Apr 13.

Departamento de Bioquímica, Farmacologia e Fisiologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Brazil.

Trypanosoma rangeli is a hemoflagellate parasite which is able to infect humans. Distinct from Trypanosoma cruzi, the causative agent of Chagas disease, T. rangeli is non-pathogenic to the vertebrate host. The manner by which the T. rangeli interacts with the host is still unknown, but it certainly depends on the surface molecules. Major surface proteins (MSP) are GPI-anchored, zinc-dependent metalloproteases present in the surface of all trypanosomatids studied so far, which are implicated as virulence factors in pathogenic trypanosomatids, such as Leishmania spp and T. cruzi. The aims of this work were to generate the complete sequence of a T. rangeli MSP (TrMSP) gene and to determine the 3D-structure of the predicted protein by homology modeling. The plasmid bearing a complete copy of a TrMSP gene was completely sequenced and the predicted protein was modeled using Modeller software. Results indicate that TrMSP open reading frame (ORF) codes for a predicted 588 amino acid protein and shows all elements required for its posttranslational processing. Multiple sequence alignment of TrMSP with other trypanosomatids' MSPs showed an extensive conservation of the N-terminal and central regions and a more divergent C-terminal region. Leishmania major MSP (LmMSP), which had its crystal structure previously determined, has an overall 35% identity with TrMSP. This identity allowed the comparative molecular modeling of TrMSP, which demonstrated a high degree of structural conservation between MSPs from other trypanosomatids (TrypMSPs). All modeled MSPs have a conserved folding pattern, apart from structural divergences in the C-domain and discrete differences of charge and topology in the catalytic cleft, and present the same geometry of the canonical HEXXH zinc-binding motif. The determination of surface charges of the molecules revealed that TrMSP is a predominantly positive protein, whereas LmMSP and Trypanosoma cruzi MSP (TcMSP) are negative proteins, suggesting that substrates recognized by TcMSP and LmMSP could not interact with TrMSP. Moreover, the comparison between TrMSP and TcMSP protein sequences has revealed 45 non-neutral amino acid substitutions, which can be further assessed through protein engineering. The characteristics of TrMSP could explain, at least in part, the lack of pathogenicity of T. rangeli to humans and point to the necessity of identifying the biological targets of this enzyme.
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http://dx.doi.org/10.1007/s00894-013-1834-8DOI Listing
August 2013

Homogeneity of Trypanosoma cruzi I, II, and III populations and the overlap of wild and domestic transmission cycles by Triatoma brasiliensis in northeastern Brazil.

Parasitol Res 2013 Apr 31;112(4):1543-50. Epub 2013 Jan 31.

Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, Rio Grande do Norte, Brazil.

The genetic variability of 24 Trypanosoma cruzi isolates from humans (11) and triatomines (13) in northeastern Brazil was analyzed by random amplified polymorphic DNA (RAPD) and compared with taxonomic groups, host, and geographical origin of the parasite. TcI (12.5%), TcII (45.8%), and TcIII (41.6%) showed a similarity coefficient (SC) of 0.74 using the mean of three primers and 0.80, 0.75, and 0.66 for λgt11-F, M13-40F, and L15996 primers, respectively. The samples were clustered according to their phylogenetic origin in two polymorphic and divergent branches: one associated with TcI and the other with two subbranches corresponding to TcII and TcIII. TcI was only identified in humans and correlated with the Id homogenous group (0.80 SC). TcII from humans and Triatoma brasiliensis showed 0.86 SC and was clustered according monoclonal or polyclonal populations with similar RAPD profiles detected among the vector and/or humans in different municipalities. TcIII was isolated exclusively in sylvatic cycles from T. brasiliensis and Panstrongylus lutzi and showed low variability (0.84 SC) and high homology mainly among isolated populations at the same locality. The homology of T. cruzi among different hosts and locations suggests the distribution of principal clones circulating and reveals an overlapping between the sylvatic and domestic cycles in this area, where T. brasiliensis infected with TcII acts as link in both environments. This species is important to maintain TcII and TcIII in wild cycles and deserves particular attention due an emergent risk of these populations being introduced into the domestic cycle; moreover, its clinical and epidemiological implications remain unknown.
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http://dx.doi.org/10.1007/s00436-013-3301-yDOI Listing
April 2013

Trypanosoma cruzi experimental congenital transmission associated with TcV and TcI subpatent maternal parasitemia.

Parasitol Res 2013 Feb 18;112(2):671-8. Epub 2012 Nov 18.

Discipline of Parasitology, Department of Biological Sciences, Universidade Federal do Triângulo Mineiro, Rua Frei Paulino, 30, Bairro Abadia, 38025-180, Uberaba, Minas Gerais, Brazil.

The congenital transmission of Chagas disease is associated with an increase in parasitemia during pregnancy, maternal and fetal immunity, and populations of Trypanosoma cruzi. In this study, the biological behavior of TcI and TcV (isolated from a human congenital case) strains and their potential for experimental congenital transmission were evaluated in female BALB/C mice. Parasitemia was estimated by fresh blood examination, semiquantitative microhematocrit, and hemoculture, while congenital transmission was evaluated by culture in the liver infusion tryptose medium and by polymerase chain reaction (PCR) of the pups' tissues on postnatal day 7 and of the pups' blood sample at 30 days after birth. Infection was detected in 100 % of the females. Both strains showed subpatent parasitemia, which was higher for TcV infection. The presence of amastigote nest was detected only in an animal infected with TcI. The inflammatory process was more frequent (p = 0.001) in the tissues of the animals infected with TcV (58.6 %) than TcI (31.1 %). The fertility rates of females mated after 35 days postinfection were similar (90 % for TcV, 88.9 % for TcI; p = 0.938). Parasitemia did not change during pregnancy. The average number of pups/female was greater (p = 0.03) in mice with TcV infection (8.30) than in those with TcI infection (4.78). Congenital transmission was detected exclusively by PCR in 50.9 % of the pups, 46.6 % for TcV and 58.1 % for TcI. The PCR positivity for TcI was higher in the blood than in the tissue (p = 0.003). These results demonstrate the T. cruzi experimental congenital infection associated with subpatent maternal parasitemia of TcI and TcV.
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http://dx.doi.org/10.1007/s00436-012-3184-3DOI Listing
February 2013

Autonomic nervous system modulation affects the inflammatory immune response in mice with acute Chagas disease.

Exp Physiol 2012 Nov 15;97(11):1186-202. Epub 2012 Jun 15.

Biological Sciences Institute, Triangulo Mineiro Federal University, Uberaba, MG, Brazil.

The aim of the present study was to evaluate the effects of changes to the autonomic nervous system in mice during the acute phase of Chagas disease, which is an infection caused by the parasite Trypanosoma cruzi. The following types of mice were inoculated with T. cruzi (CHG): wild-type (WT) and vesicular acetylcholine transporter knockdown (KDVAChT) C57BL/6j mice; wild-type non-treated (NT) FVB mice; FVB mice treated with pyridostigmine bromide (PYR) or salbutamol (SALB); and β(2)-adrenergic receptor knockout (KOβ2) FVB mice. During infection and at 18-21 days after infection (acute phase), the survival curves, parasitaemia, electrocardiograms, heart rate variability, autonomic tonus and histopathology of the animals were evaluated. Negative control groups were matched for age, genetic background and treatment. The KDVAChT-CHG mice exhibited a significant shift in the electrocardiographic, autonomic and histopathological profiles towards a greater inflammatory immune response that was associated with a reduction in blood and tissue parasitism. In contrast, the CHG-PYR mice manifested reduced myocardial inflammation and lower blood and tissue parasitism. Similar results were observed in CHG-SALB animals. Unexpectedly, the KOβ2-CHG mice exhibited less myocardial inflammation and higher blood and tissue parasitism, which were associated with reduced mortality. These findings could have been due to the increase in vagal tone observed in the KOβ2 mice, which rendered them more similar to the CHG-PYR animals. In conclusion, our results indicate a marked immunomodulatory role for the parasympathetic and sympathetic autonomic nervous systems, which inhibit both the inflammatory immune response and parasite clearance during the acute phase of experimental Chagas heart disease in mice.
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http://dx.doi.org/10.1113/expphysiol.2012.066431DOI Listing
November 2012

RAPD analysis with the primer L15996 of Brazilian clinical and environmental Cryptococcus neoformans isolates.

Mycopathologia 2012 Jul 17;174(1):53-9. Epub 2012 Jan 17.

Infectious Diseases Unit, Triangulo Mineiro Federal University, Avenida Frei Paulino, 30, Uberaba, Minas Gerais, CEP 38025-180, Brazil.

Different methods have been used to perform the molecular characterization of Cryptococcus neoformans. Among them, RAPD analysis is able to separate isolates of the same species and genotypes. This study aimed to evaluate clinical and environmental C. neoformans isolates from Minas Gerais, Brazil by RAPD and correlate the genetic profiles with the ones obtained by URA5-RFLP, virulence factors and antifungal susceptibility patterns. Forty-five environmental (31 from areas surrounding hospital and 14 from captive bird droppings from pet-shops) and 29 clinical C. neoformans isolates were evaluated. Antifungal susceptibility tests (Clinical and Laboratory Standards Institute), URA5-RFLP analysis and the assessment of virulence factors were performed according to their original descriptions. RAPD profiles were obtained using the L15996 primer (5'-CTCCACCATTAGCACCCAAAGC-3'). RAPD analysis generated two to 20 bands for all studied isolates. The isolates presented similarities ranging from 10.8 to 100.0%. Considering a minimum identity score of 50%, four clusters were formed. Cluster I contained 10 pet-shops bird dropping isolates, cluster II contained 22 clinical isolates most of them recovered from cerebrospinal fluid, cluster III contained 14 isolates from hospital surroundings and cluster IV contained 12 environmental isolates most from hospital surroundings. Fourteen isolates were not grouped. The RAPD profiles were clustered according to their source and URA5-RFLP pattern. No correlation between virulence factors or antifungal susceptibility profile with the obtained RAPD profiles was observed.
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http://dx.doi.org/10.1007/s11046-011-9515-6DOI Listing
July 2012

The revised Trypanosoma cruzi subspecific nomenclature: rationale, epidemiological relevance and research applications.

Infect Genet Evol 2012 Mar 27;12(2):240-53. Epub 2011 Dec 27.

Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Avenida Professor Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil.

The protozoan Trypanosoma cruzi, its mammalian reservoirs, and vectors have existed in nature for millions of years. The human infection, named Chagas disease, is a major public health problem for Latin America. T. cruzi is genetically highly diverse and the understanding of the population structure of this parasite is critical because of the links to transmission cycles and disease. At present, T. cruzi is partitioned into six discrete typing units (DTUs), TcI-TcVI. Here we focus on the current status of taxonomy-related areas such as population structure, phylogeographical and eco-epidemiological features, and the correlation of DTU with natural and experimental infection. We also summarize methods for DTU genotyping, available for widespread use in endemic areas. For the immediate future multilocus sequence typing is likely to be the gold standard for population studies. We conclude that greater advances in our knowledge on pathogenic and epidemiological features of these parasites are expected in the coming decade through the comparative analysis of the genomes from isolates of various DTUs.
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http://dx.doi.org/10.1016/j.meegid.2011.12.009DOI Listing
March 2012

Antifungal susceptibility, enzymatic activity, PCR-fingerprinting and ITS sequencing of environmental Cryptococcus laurentii isolates from Uberaba, Minas Gerais, Brazil.

Mycopathologia 2012 Jul 25;174(1):41-52. Epub 2011 Nov 25.

Department of Infectious and Parasitic Diseases, Triangulo Mineiro Federal University, Postal Code 118, Uberaba, MG, 38001-170, Brazil.

Cryptococcus laurentii has been classically considered a saprophytic species, although several cases of human infection have been already reported. This study aimed to evaluate the phospholipase, proteinase and hemolysins activity, the antifungal susceptibility profile, the genetic variability by M13 and (GACA)(4) fingerprinting and the internal transcribe spacer (ITS) sequencing of 38 C. laurentii isolates recovered from captive bird droppings and surrounding hospital areas. All of them exhibited phospholipase activity, while the hemolytic activity was evidenced in 34 (89.4%) isolates. None of them exhibited proteinase activity. Twenty-seven isolates (71.1%) presented susceptibility dose dependent to fluconazole. Most isolates (94.7%) were susceptible to voriconazole, while one (2.65%) was resistant to this drug. Twenty-one (55.3%) isolates showed reduced susceptibility to itraconazole while nine (23.7%) were resistant. Three (7.9%) and five (13.1%) isolates exhibited resistance to ketoconazole and amphotericin B, respectively. Most C. laurentii fingerprinting obtained with M13 and (GACA)(4) showed high heterogeneity. By using the two primers, seven (18.4%) isolates grouped as A (CL2, CL7, and CL8), B (CL35, CL38) and C (CL29, CL30) with 100% similarity. Different from most variable surrounding hospital isolates, all but one of the pet shops strains clustered with the two primers, although they had been recovered from different neighborhoods. All isolates were identified as C. laurentii phylogenetic group I by ITS sequencing. Thus, the presence of virulence factors, a decreased antifungal susceptibility and a heterogeneous molecular pattern of the C. laurentii isolates here described suggests this species can be a potential pathogen in the context of the immunocompromised population.
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http://dx.doi.org/10.1007/s11046-011-9500-0DOI Listing
July 2012

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

Rev Soc Bras Med Trop 2011 Nov-Dec;44(6):684-90. Epub 2011 Nov 21.

Programa de Pós-Graduação em Medicina Tropical e Infectologia, Departamento de Clínica Médica, Universidade Federal do Triângulo Mineiro, Uberaba, MG, Brasil.

Introduction: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco.

Methods: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD (random amplified polymorphic DNA).

Results: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10(6) to 10(7) parasites/mL) and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal) muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin.

Conclusions: The Mexican T. cruzi strains are myotrophic and belong to group TcI.
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http://dx.doi.org/10.1590/s0037-86822011005000058DOI Listing
September 2012

The relationship between heart rate variability and serum cytokines in chronic chagasic patients with persistent parasitemia.

Pacing Clin Electrophysiol 2011 Jun 28;34(6):724-35. Epub 2011 Jan 28.

Internal Medicine Department, Infectious Division, Federal University of the Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.

Background: Persistent parasitemia, immunological, and autonomic nervous system impairments may play an important role in the evolution and clinical outcome of the chronic phase of Chagas' disease by triggering functional cardiovascular changes.

Methods: Three groups were evaluated: 17 chronic chagasic patients with the indeterminate form (IChD), 12 chronic chagasic patients with cardiac forms (ChHD), and 29 individuals as a healthy control group. Parasitemia was assessed by polymerase chain reaction; hemoculture, heart rate variability by linear and nonlinear methods, and interleukin (IL)-1β, IL-4, IL-6, IL-10, IL-12, IL-13, IL-17, and tumor necrosis factor-α, and interferon (IFN)-γ serum cytokines were assessed by enzyme-linked immune assay.

Results: Twenty-nine chronic chagasic patients were positive for parasitemia (17 IChD and 12 ChHD). Heart rate variability parameters in baseline condition and after cold face test were significantly decreased in chagasic patients compared to controls. Tilt tests showed no alteration. However, using nonlinear indices, ChHD patients presented lower values compared to IChD and controls. Differences in the expression of serum cytokines were observed between chagasic patients and controls. However, among the groups, ChHD presented higher median values of IL-10 and lower of IFN-γ compared to IChD.

Conclusion: Both chagasic groups present an autonomic impairment using linear methods. The nonlinear methods revealed that the ChHD group had a higher cardiovascular risk. Serum cytokine concentrations between chagasic patients were similar. However, ChHD showed higher concentrations of IL-10 and lower of IFN-γ, suggesting some established process of immune regulation.
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http://dx.doi.org/10.1111/j.1540-8159.2010.03025.xDOI Listing
June 2011

Polymorphisms in the 18S rDNA gene of Cystoisospora belli and clinical features of cystoisosporosis in HIV-infected patients.

Parasitol Res 2011 Mar 22;108(3):679-85. Epub 2010 Oct 22.

Disciplina de Parasitologia, Universidade Federal do Triângulo Mineiro, Rua Frei Paulino 30, Abadia, CEP 38025-180 Uberaba, Minas Gerais, Brazil.

Intraspecific variability among Cystoisospora belli isolates and its clinical implications in human cystoisosporosis have not been established. In this study, the restriction fragment length polymorphisms in a 1.8-kb amplicon of the small subunit ribosomal DNA (SSU rDNA) of the parasite was investigated in 20 C. belli-positive stool samples obtained from 15 HIV-infected patients. Diarrheic syndrome was observed in all patients with cystoisosporosis and the number of diarrheic episodes per patient during hospitalization ranged from 1 to 26 (mean of 9.64 ± 9.30), with a mean duration of 2 to 12 days (mean of 5.90 ± 3 days). Three restriction profiles (RF) were generated with MboII digestion, which were named RFI, RFII, and RFIII. Two isolates obtained from a patient with extraintestinal cystoisosporosis showed distinct restriction profiles with MboII. This study demonstrates that patients can be infected with different C. belli genotypes, and this information may be useful for identifying new C. belli genotypes infecting humans.
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http://dx.doi.org/10.1007/s00436-010-2113-6DOI Listing
March 2011

Socioepidemiological screening of serologically ineligible blood donors due to Chagas disease for the definition of inconclusive cases.

Mem Inst Oswaldo Cruz 2010 Sep;105(6):800-5

Departamento de Clínica Médica, Universidade Federal do Triângulo Mineiro, Uberaba, Minas Gerais, Brazil.

Epidemiological screening combined with serological tests has become an important tool at blood banks for the characterization of donors with or without Trypanosoma cruzi infection. Thus, the objective of the present study was to describe the sociodemographic and epidemiological characteristics of blood donors with non-negative serology for T. cruzito determine possible risk factors associated with serological ineligibility. Sociodemographic and epidemiological data were collected by analysis of patient histories and interviews. The data were analyzed descriptively using absolute and relative frequencies and odds ratio (OR) evaluation. The frequency of serological ineligibility was 0.28%, with a predominance of inconclusive reactions (52%) and seropositivity among first-time donors (OR = 607), donors older than 30 years (OR = 3.7), females (OR = 1.9), donors from risk areas (OR = 4) and subjects living in rural areas (OR = 1.7). The risk of seropositivity was higher among donors who had contact with the triatomine vector (OR = 11.7) and those with a family history of Chagas disease (OR = 4.8). The results demonstrate the value of detailed clinical-epidemiological screening as an auxiliary tool for serological definition that, together with more specific and more sensitive laboratory methods, will guarantee a higher efficacy in the selection of donors at blood centres.
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http://dx.doi.org/10.1590/s0074-02762010000600012DOI Listing
September 2010