Trypanosoma cruzi I genotype among isolates from patients with chronic Chagas disease followed at the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, Brazil)

Oliveira, Tatiana da Silva Fonseca de; Santos, Barbara Neves dos; Galdino, Tainah Silva; Hasslocher‐Moreno, Alejandro Marcel; Bastos, Otílio Machado Pereira; Sousa, Maria Auxiliadora de

doi:10.1590/0037-8682-0406-2016

Cited by 5 publications

(9 citation statements)

References 70 publications

(141 reference statements)

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“…This scenario could be a valuable strategy for T. cruzi to establish the chronic phase of Chagas disease, since these arrested parasites would partially halt host-cell colonization, reducing the number of trypomastigotes released to the extracellular milieu, thus decreasing parasite detection by the host immune system. This hypothesis would be in accordance with the clinically-observed patterns of Chagas disease progression and strain-dependent chronicity, in which naturally-hybrid strains show higher rates of chronification (Oliveira et al, 2017). On the other hand, T. cruzi strains that present less percentage of arrested cells would be less prone to establish a chronic infection.…”

Section: Discussionsupporting

confidence: 78%

“…TcI occurs across North, Central, and South America-especially in Colombia and Venezuela-and is represented by strains with high replication rates and high parasitemia, leading to high mortality around 20-30 days post-infection (Zingales et al, 2012;Zingales, 2018). TcII presents higher replication and infection rates when compared to TcI, with a parasitemia peak around 12-20 days post-infection, when it promotes high mortality levels (Zingales et al, 2012;Oliveira et al, 2017). TcIII leads to low parasitemia, with its peak around 15-20 days postinfection, and is not related with chronic cases, being rarely documented in human infection (Zingales et al, 2012;Ragone et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

“…TcV and TcVI are less infective and display lower replication rates, but are largely related with severe chronic and congenital human disease. They occur mostly in South America within domestic transmission cycles (Zingales et al, 2012;Brenière et al, 2016;Oliveira et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

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The Influence of Recombinational Processes to Induce Dormancy in Trypanosoma cruzi

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Oliveira

Guañabens

et al. 2020

Front. Cell. Infect. Microbiol.

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the involvement of homologous recombination in the determination of dormancy in T. cruzi, we treated CL Brener cells with gamma radiation, which generates DNA lesions repaired by this process. Interestingly, the dormancy percentage was increased in gamma-irradiated cells. Since, we have previously shown that naturally-occurring hybrid T. cruzi strains present higher transcription of RAD51-a key gene in recombination process-we also measured the percentage of dormant cells from T. cruzi clone CL Brener harboring single knockout for RAD51. Our results showed a significative reduction of dormant cells in this T. cruzi CL Brener RAD51 mutant, evidencing a role of homologous recombination in the process of dormancy in this parasite. Altogether, our data suggest the existence of an adaptive difference between T. cruzi strains to generate dormant cells, and that homologous recombination may be important for dormancy in this parasite.

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Section: Discussionsupporting

confidence: 78%

Section: Introductionmentioning

confidence: 99%

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The Influence of Recombinational Processes to Induce Dormancy in Trypanosoma cruzi

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Oliveira

Guañabens

et al. 2020

Front. Cell. Infect. Microbiol.

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“…The previous knowledge about DTUs in Chagas disease patients points out the prevalence of TcII and TcVI within the area of vectorial domestic transmission in Brazil [ 5 , 19 ]. In a recent study with nine patients from Pernambuco (PE), Paraíba (PB), Bahia (BA), Minas Gerais (MG), and Rio Grande do Sul (RS) states [ 36 ], also assisted at the outpatient clinic from the Instituto Nacional de Infectologia Evandro Chagas (INI) at Fundação Oswaldo Cruz (Fiocruz) , T . cruzi was isolated from blood samples and the DTUs were identified.…”

Section: Discussionmentioning

confidence: 99%

Exploring the parasite load and molecular diversity of Trypanosoma cruzi in patients with chronic Chagas disease from different regions of Brazil

et al. 2018

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Chagas disease is still a major public health issue in many Latin American countries. One of the current major challenges is to find an association between Trypanosoma cruzi discrete typing units (DTUs) and clinical manifestations of the disease. In this study, we used a multilocus conventional PCR and quantitative real time PCR (qPCR) approaches to perform the molecular typing and parasite load quantification directly from blood specimens of 65 chronic Chagas disease patients. All patients were recruited at the same health center, but their place of birth were widely distributed in different geographic regions of Brazil. Of the 65 patients, 35 (53.8%) presented positive amplification by real time qPCR, being 20 (30.7%) with the clinical indeterminate form and 15 (23.1%) with the cardiac form of the disease. The parasite load median for all positive patients was 2.54 [1.43–11.14] parasite equivalents/mL (par. Eq./mL), with the load ranging from 0.12 to 153.66 par. Eq./mL. Noteworthy, the parasite load was significantly higher in patients over 70 years old (median 20.05 [18.29–86.86] par. Eq./mL). Using guanidine-EDTA blood samples spiked with reference T. cruzi strains, belonging to the six DTUs, it was possible to genotype the parasite up to 0.5 par. Eq./mL, with high specificity. Of the patients with positive qPCR, it was possible to identify the T. cruzi DTU in 28 patients (80%). For the remaining patients (20%), at least a partial result was obtained. Analysis of specimens showed prevalences of TcVI, TcII and mixed infection TcVI+TcII equal to 40%, 17.1% and 14.3%, respectively. In addition, two patients were infected by TcV, and one patient was coinfected by TcIII+TcVI, These last three patients were in stage A of chronic chagasic cardiomyopathy (CCC), and they were born at the Bahia State (northeast region of Brazil). When T. cruzi genotypes were compared with the parasite load, more elevated parasite loads were observed in patients infected by TcII in general (parasite load median of 7.56 par. Eq./mL) in comparison to patients infected by TcVI (median of 2.35 par. Eq./mL). However, while the frequency of CCC was 50% in patients infected by TcVI and TcV, only 16.7% of patients infected by TcII evolved to CCC. Taking together, our results contribute to update the epidemiological knowledge of T. cruzi DTUs in Brazil, and highlight the age of patient and infection by TcII as important features that lead to the observation of higher parasitemia levels.

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“…However, the number of TcVI patients is too low for any conclusion to be drawn. Other studies that enrolled patients of our institution also identified TcVI genetic material in the blood drawn from patients born in the Southeast and Northeast Brazilian regions [11,40]. TcVI was found to be associated to both cardiac and indeterminate forms of chronic Chagas disease in Brazil [11,40,41].…”

Section: Plos Onementioning

confidence: 84%

Association between Trypanosoma cruzi DTU TcII and chronic Chagas disease clinical presentation and outcome in an urban cohort in Brazil

et al. 2020

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Background The specific roles of parasite characteristics and immunological factors of the host in Chagas disease progression and prognosis are still under debate. Trypanosoma cruzi genotype may be an important determinant of the clinical chronic Chagas disease form and prognosis. This study aimed to identify the potential association between T. cruzi genotypes and the clinical presentations of chronic Chagas disease. Methodology/principal findings This is a retrospective study using T. cruzi isolated from blood culture samples of 43 patients with chronic Chagas disease. From 43 patients, 42 were born in Brazil, mainly in Southeast and Northeast Brazilian regions, and one patient was born in Bolivia. Their mean age at the time of blood collection was 52.4±13.2 years. The clinical presentation was as follows 51.1% cardiac form, 25.6% indeterminate form, and 23.3% cardiodigestive form. Discrete typing unit (DTU) was determined by multilocus conventional PCR. TcII (n = 40) and TcVI (n = 2) were the DTUs identified. DTU was unidentifiable in one patient. The average follow-up time after blood culture was 5.7±4.4 years. A total of 14 patients (32.5%) died and one patient underwent heart transplantation. The cause of death was sudden cardiac arrest in six patients, heart failure in five patients, not related to Chagas disease in one patient, and ignored in two patients. A total of 8 patients (18.6%) progressed, all of them within the cardiac or cardiodigestive forms. Conclusions/significance TcII was the main T. cruzi DTU identified in chronic Chagas disease Brazilian patients (92.9%) with either cardiac, indeterminate or cardiodigestive forms, born at Southeast and Northeast regions. Other DTU found in much less frequency was TcVI (4.8%). TcII was also associated to patients that evolved with heart failure or sudden cardiac arrest, the two most common and ominous consequences of the cardiac form of Chagas disease.

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Trypanosoma cruzi I genotype among isolates from patients with chronic Chagas disease followed at the Evandro Chagas National Institute of Infectious Diseases (FIOCRUZ, Brazil)

Cited by 5 publications

References 70 publications

The Influence of Recombinational Processes to Induce Dormancy in Trypanosoma cruzi

The Influence of Recombinational Processes to Induce Dormancy in Trypanosoma cruzi

Exploring the parasite load and molecular diversity of Trypanosoma cruzi in patients with chronic Chagas disease from different regions of Brazil

Association between Trypanosoma cruzi DTU TcII and chronic Chagas disease clinical presentation and outcome in an urban cohort in Brazil

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