Do Radically Dissimilar Trypanosoma Cruzi Strains (Zymodemes) Cause Venezuelan and Brazilian Forms of Chagas' Disease?

Miles, Michael A.; Póvoa, Marinete Marins; Prata, Áluízio; Cedillos, R. A.; Souza, Álvaro Nogueira de; Macêdo, Vanize

doi:10.1016/s0140-6736(81)92518-6

Cited by 222 publications

(154 citation statements)

References 14 publications

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“…In fact, infrequent chronic cardiac cases of Chagas disease confirm that parasites circulating in this area cause myocardiopathy, appearing clinically as cardiac insufficiency, arrhythmogenic syndrome, or thromboembolism [28][29][30][31][32][33] . The absence of histopathological alterations in the large intestine indicates that the parasites studied did not have the capacity to cause digestive Chagas disease, in agreement with the absence of records of mega syndromes in Amazonian countries and Central and North America 34 .…”

Section: Ethical Considerationssupporting

confidence: 83%

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

Monteiro

Magalhães

Oliveira

et al. 2012

Rev. Soc. Bras. Med. Trop.

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Introduction:The biological diversity of circulating Trypanosoma cruzi stocks in the Amazon region most likely plays an important role in the peculiar clinic-epidemiological features of Chagas disease in this area. Methods: Seven stocks of T. cruzi were recently isolated in the State of Amazonas, Brazil, from humans, wild mammals, and triatomines. They belonged to the TcI and Z3 genotypes and were biologically characterized in Swiss mice. Parasitological and histopathological parameters were determined. Results: Four stocks did not promote patent parasitemia in mice. Three stocks produced low parasitemia, long pre-patent periods, and a patent period of 1 day or oscillating parasitemia. Maximum parasitemia ranged from 1,400 to 2,800 trypomastigotes/0.1mL blood. Mice inoculated with the T. cruzi stocks studied showed low positivity during fresh blood examinations, ranging from 0% to 28.6%. In hemoculture, positivity ranged from 0% to 100%. Heart tissue parasitism was observed in mice inoculated with stocks AM49 and AM61. Stock AM49 triggered a moderate inflammatory process in heart tissue. A mild inflammatory process was observed in heart tissue for stocks AM28, AM38, AM61, and AM69. An inflammatory process was frequently observed in skeletal muscle. Examinations of brain tissue revealed inflammatory foci and gliosis in mice inoculated with stock AM49. Conclusions: Biological and histopathological characterization allowed us to demonstrate the low infectivity and virulence of T. cruzi stocks isolated from the State of Amazonas. Keywords: Chagas disease. Trypanosoma cruzi. Virulence. Pathogenicity. Swiss mice. Amazon. RESUMO Introdução:A diversidade biológica dos estoques Trypanosoma cruzi circulantes na Região Amazônica pode desempenhar importante papel nas características clínico-epidemiológicas peculiares da doença de Chagas nesta área. Métodos: Sete isolados de T. cruzi do Estado do Amazonas provenientes de humanos, mamíferos silvestres e triatomíneos, pertencentes aos genótipos TcI e Z3, foram biologicamente caracterizados em camundongos Swiss. Foram avaliados parâmetros parasitológicos e histopatológicos. Resultados: Quatro isolados não produziram parasitemia patente em camundongos. Três isolados promoveram baixa parasitemia com longos períodos pré-patentes, período patente de um dia ou parasitemia oscilante. A parasitemia máxima variou de 1.400 a 2.800 tripomastigotas/0,1mL de sangue. Os camundongos inoculados com os isolados estudados mostraram baixa positividade no exame a fresco, variando de 0 a 28,6%. Para a hemocultura, a positividade variou de 0 a 100%. Parasitismo cardíaco foi observado em camundongos inoculados com os isolados AM49 e AM61. O isolado AM49 produziu inflamação moderada no tecido cardíaco. Processo inflamatório discreto foi observado no tecido cardíaco de camundongos inoculados com os isolados AM28, AM38, AM61 e AM69. Processo inflamatório em músculo esquelético foi muito frequente. O exame do tecido cerebral revelou focos inflamatórios e gliose em camundongos inoculados com o i...

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Section: Ethical Considerationssupporting

confidence: 83%

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

Monteiro

Magalhães

Oliveira

et al. 2012

Rev. Soc. Bras. Med. Trop.

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“…Moreover, 10-30 years after initial infection, some patients may develop the cardiac, digestive, and/or cardiodigestive clinical forms 12 . There are major variations in clinical manifestations and morbidities among patients with ChD 13,14 ; these differences can be attributed in part to the effectiveness of the immune response, genetic aspects of infected individuals, and the complex structure of the T. cruzi population 15,16 .…”

Section: Introductionmentioning

confidence: 99%

Combined parasitological and molecular-based diagnostic tools improve the detection of Trypanosoma cruzi in single peripheral blood samples from patients with Chagas disease

Volpato

Sousa

D’Ávila

et al. 2017

Rev. Soc. Bras. Med. Trop.

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Introduction:In order to detect Trypanosoma cruzi and determine the genetic profiles of the parasite during the chronic phase of Chagas disease (ChD), parasitological and molecular diagnostic methods were used to assess the blood of 91 patients without specific prior treatment. Methods: Blood samples were collected from 68 patients with cardiac ChD and 23 patients with an indeterminate form of ChD, followed by evaluation using blood culture and polymerase chain reaction. T. cruzi isolates were genotyped using three different genetic markers. Results: Blood culture was positive in 54.9% of all patients, among which 60.3% had the cardiac form of ChD, and 39.1% the indeterminate form of ChD. There were no significant differences in blood culture positivity among patients with cardiac and indeterminate forms. Additionally, patient age and clinical forms did not influence blood culture results. Polymerase chain reaction (PCR) was positive in 98.9% of patients, although comparisons between blood culture and PCR results showed that the two techniques did not agree. Forty-two T. cruzi stocks were isolated, and TcII was detected in 95.2% of isolates. Additionally, one isolate corresponded to TcIII or TcIV, and another corresponded to TcV or TcVI. Conclusions: Blood culture and PCR were both effective for identifying T. cruzi using a single blood sample, and their association did not improve parasite detection. However, we were not able to establish an association between the clinical form of ChD and the genetic profile of the parasite.

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“…Over the years, numerous approaches have been used to characterise the population structure of T. cruzi, aiming at defining the number of relevant subgroups. Accordingly, these subgroups received different designations, including zymodemes (Miles et al 1977, 1978, 1981, Romanha et al 1979, schizodemes (Morel et al 1980), biodemes (Andrade 1974, Andrade & Magalhães 1997, clonets (Tibayrenc & Ayala 1991), lineages (Souto et al 1996), clades (Kawashita et al 2001) and, more recently, discrete typing units (DTUs) (Tibayrenc 1998) and haplotypes (Freitas et al 2006, Herrera et al 2007.…”

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confidence: 99%

“…T. cruzi strains characterised by biological and biochemical features (e.g., biodemes and zymodemes) and molecular techniques [e.g., multilocus enzyme electrophoresis (MLEE), random amplification of polymorphic DNA (RAPD), mini-exon and 24Sα ribosomal DNA sequences] should be classified into two principal groups, named T. cruzi I and T. cruzi II. The classification of apparent hybrid strains and strains equivalent to Zymodeme 3 (Miles et al 1978(Miles et al , 1981 and Biodeme Type I (Andrade 1974) would be decided later after further studies.…”

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confidence: 99%

A new consensus for Trypanosoma cruzi intraspecific nomenclature: second revision meeting recommends TcI to TcVI

Zingales

Briones

et al. 2009

Mem. Inst. Oswaldo Cruz

895

714

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In an effort to unify the nomenclature of Trypanosoma cruzi, the causative agent of Chagas disease, an updated system was agreed upon at the Second Satellite Meeting. A consensus was reached that T. cruzi strains should be referred to by six discrete typing units (T. cruzi I-VI). The goal of a unified nomenclature is to improve communication within the scientific community involved in T. cruzi research. The justification and implications will be presented in a subsequent detailed report.

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Do Radically Dissimilar Trypanosoma Cruzi Strains (Zymodemes) Cause Venezuelan and Brazilian Forms of Chagas' Disease?

Cited by 222 publications

References 14 publications

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

Biological behavior of Trypanosoma cruzi stocks obtained from the state of Amazonas, Western Brazilian Amazon, in mice

Combined parasitological and molecular-based diagnostic tools improve the detection of Trypanosoma cruzi in single peripheral blood samples from patients with Chagas disease

A new consensus for Trypanosoma cruzi intraspecific nomenclature: second revision meeting recommends TcI to TcVI

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