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1.
Parasitology ; 133(Pt 5): 603-11, 2006 Nov.
Article in English | MEDLINE | ID: mdl-16836794

ABSTRACT

In order to better comprehend the putative association between genotype Trypanosoma cruzi II and primates, an evaluation of the infection in free ranging primates and specimens born in captivity from different geographical areas, the Amazon and the Atlantic forest, was carried out. Seroprevalences of the T. cruzi infection among the primates was similar in both biomes (45.5% and 46%). The parasites were isolated from 8 and 4 different species of primates, respectively from the Amazon and Atlantic forest. Multi-locus enzyme electrophoresis (MLEE) typed the isolates from Amazon as zymodeme 1. Mini-exon gene analysis characterized all these isolates as T. cruzi I, the main genotype circulating in the region. In the Atlantic forest, primates infected with TCI and TCII, as well as a mixed infection (TCI and TCII), were detected. These findings prove that primates may maintain stable infections by both genotypes. Moreover, data show that T. cruzi can occur in a wide range of primate genera, independent of their social behaviour, niches or habitats. Considering the high seroprevalence and stability of T. cruzi infection among the primates, these animals play an important role in the maintenance of the parasite in nature.


Subject(s)
Animals, Zoo/parasitology , Antibodies, Protozoan/blood , Chagas Disease/veterinary , Primate Diseases/parasitology , Primates/parasitology , Trypanosoma cruzi/isolation & purification , Animals , Animals, Zoo/classification , Brazil/epidemiology , Chagas Disease/parasitology , Chagas Disease/prevention & control , Chagas Disease/transmission , Comorbidity , Ecology , Exons/genetics , Genes, Protozoan/genetics , Prevalence , Primate Diseases/prevention & control , Primate Diseases/transmission , Primates/classification , Seroepidemiologic Studies , Species Specificity , Trypanosoma cruzi/classification , Trypanosoma cruzi/genetics , Trypanosoma cruzi/immunology , Viremia
2.
Trans R Soc Trop Med Hyg ; 99(5): 379-88, 2005 May.
Article in English | MEDLINE | ID: mdl-15780345

ABSTRACT

We studied the prevalence of Trypanosoma cruzi infection among eight species of wild small mammals (n=289) in an area where human cases of infection/disease have occurred. Dogs (n=52) and goats (n=56) were also surveyed. The study was carried out inside a biological reserve, the National Park 'Serra da Capivara' and its surroundings in Piaui State, Brazil. The marsupial Didelphis albiventris and the caviomorph rodent Trichomys apereoides were found to be the most important reservoirs in the study area. Trichomys apereoides was the most abundant species (80%) and D. albiventris the most frequently infected (61%). Both T. cruzi I and T. cruzi II genotypes were isolated from these species. One specimen of Tr. apereoides displayed a mixed T. cruzi I/zymodeme 3 infection. Serum prevalence among dogs suggests that they may be involved in the maintenance of the parasite in the peridomestic environment, in contrast to goats, which are not apparently of any epidemiological importance. The distinct distribution and patterns of infection observed in the study areas suggest that even in the same biome, epidemiological studies or determination of control measures must take into account ecological peculiarities.


Subject(s)
Chagas Disease/epidemiology , Chagas Disease/veterinary , Mammals/parasitology , Animals , Brazil/epidemiology , Disease Reservoirs/veterinary , Dog Diseases/epidemiology , Dog Diseases/parasitology , Dogs , Electrophoresis, Agar Gel , Goat Diseases/epidemiology , Goat Diseases/parasitology , Goats , Trypanosoma cruzi/classification , Trypanosoma cruzi/genetics
3.
Parasitology ; 129(Pt 6): 703-11, 2004 Dec.
Article in English | MEDLINE | ID: mdl-15648693

ABSTRACT

Previous studies on infection of Trypanosoma cruzi in the Poço das Antas Biological Reserve population of wild free-ranging Leontopithecus rosalia have shown the presence of genotype T. cruzi II, associated in Brazil with human disease. Herein, this study has been extended, the infection being evaluated in L. rosalia of 3 different tamarin populations, inhabiting distinct forest areas located in the same Atlantic Coastal Rainforest. Edentata, Marsupialia, Rodentia and Chiroptera were examined exclusively in the Poço das Antas Biological Reserve. Excluding Chiroptera, T. cruzi infection was found in all orders. Biochemical and molecular characterization demonstrated that golden lion tamarins maintained stable infections by T. cruzi II. The isolates from the other mammals corresponded to T. cruzi I, suggesting independent transmission cycles occurring among the sylvatic mammals inside Poço das Antas Biological Reserve. Significant differences in the infection patterns presented by the 3 populations of wild and captive-born golden lion tamarins were noticed. In Poço das Antas a considerably higher number of positive haemocultures from tamarins with positive serological titres was observed in comparison to those obtained from other areas. The implications for conservation and public health of an active sylvatic cycle in the Atlantic Coastal Rainforest of Rio de Janeiro are discussed.


Subject(s)
Callitrichinae/parasitology , Chagas Disease/veterinary , Monkey Diseases/epidemiology , Trypanosoma cruzi/physiology , Animals , Brazil/epidemiology , Chagas Disease/epidemiology , Female , Follow-Up Studies , Genotype , Male , Trypanosoma cruzi/genetics
4.
Eur Heart J ; 22(12): 1042-51, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11428839

ABSTRACT

AIMS: Patients with atrial flutter are believed to be at lower risk of thromboembolism than patients with atrial fibrillation. However, the incidence of atrial thrombi and the need for anticoagulation in patients with atrial flutter is not well established. METHODS AND RESULTS: A prospective observational multicentre study was undertaken to assess the frequency of atrial thrombi and spontaneous echocontrast and the prevalence for aortic complex atherosclerotic lesions in a cohort of unselected patients with atrial flutter. We evaluated 134 patients (102 male, aged 70+/-9 years); exclusion criteria were history of atrial fibrillation, rheumatic mitral valve disease and mitral mechanical prosthesis. The median of atrial flutter duration was 33 days. Twelve patients had been taking warfarin for more than 7 days. One hundred and twenty-four patients (94%) underwent a transoesophageal echocardiogram, which revealed left atrial appendage thrombi in two patients (1.6%) and right atrial thrombi in one patient (1%). At least moderate left atrial echocontrast was found in 16/124 patients (13%). Complex atherosclerotic aortic plaques were detected in 10 patients (8%). Atrial flutter conversion was attempted in 93/134 patients (69%). At the 1-month follow-up, two patients experienced a thromboembolic event following restoration of sinus rhythm. CONCLUSIONS: Atrial thrombi and echocontrast, and complex aortic atherosclerotic plaques are relatively uncommon in patients with atrial flutter. Post-cardioversion embolism was observed in two patients in our study population.


Subject(s)
Anticoagulants/therapeutic use , Atrial Flutter/diagnostic imaging , Heart Diseases/diagnostic imaging , Thromboembolism/diagnostic imaging , Aged , Analysis of Variance , Aortic Diseases/diagnostic imaging , Arteriosclerosis/diagnostic imaging , Atrial Flutter/complications , Echocardiography, Three-Dimensional , Electrocardiography , Female , Heart Atria , Heart Diseases/etiology , Humans , Male , Middle Aged , Prospective Studies , Thromboembolism/etiology
5.
Trans R Soc Trop Med Hyg ; 94(5): 509-14, 2000.
Article in English | MEDLINE | ID: mdl-11132378

ABSTRACT

Thirty-five specimens of Philander frenata and 36 Didelphis marsupialis were captured in the same Atlantic forest area of Brazil between 1992 and 1994. Haemocultures showed that 50% of P. frenata and 60% of D. marsupialis were infected with Trypansoma cruzi. Biological, biochemical and molecular characterization of the isolates suggested 2 distinct transmission cycles of T. cruzi occurred between these 2 sympatric didelphids. The T. cruzi isolates could be distinguished according to their association with each marsupial species. Biochemical characterization (multilocus enzyme electrophoresis) revealed 15 zymodemes; more variability was observed among the P. frenata isolates than among the isolates from D. marsupialis. The course of natural and experimental infection in D. marsupialis and P. frenata was different and suggested that D. marsupialis was more resistant to infection than P. frenata. In the studied area, P. frenata seems to be a more important reservoir of T. cruzi than D. marsupialis, since 40% of the characterized isolates from P. frenata belonged to the T. cruzi II group, which is associated with human infections.


Subject(s)
Chagas Disease/transmission , Marsupialia/parasitology , Trypanosoma cruzi/isolation & purification , Animals , Brazil , Chagas Disease/genetics , Chagas Disease/veterinary , Mice , Phenotype , Polymorphism, Genetic , Trypanosoma cruzi/genetics
6.
Mem Inst Oswaldo Cruz ; 94(3): 397-402, 1999.
Article in English | MEDLINE | ID: mdl-10348990

ABSTRACT

The infection pattern in Swiss mice and Triatomine bugs (Rhodnius neglectus) of eleven clones and the original stock of a Trypanosoma cruzi isolate, derived from a naturally infected Didelphis marsupialis, were biochemically and biologically characterized. The clones and the original isolate were in the same zymodeme (Z1) except that two clones were found to be in zymodeme 2 when tested with G6PDH. Although infective, neither the original isolate nor the clones were highly virulent for the mice and lesions were only observed in mice infected with the original stock and one of the clones (F8). All clones and the original isolate infected bugs well while only the original isolate and clones E2 and F3 yielded high metacyclogenesis rates. An observed correlation between absence of lesions in the mammal host and high metacyclogenesis rates in the invertebrate host suggest a evolutionary trade off i.e. a fitness increase in one trait which is accompanied by a fitness reduction in a different one. Our results suggest that in a species as heterogeneous as T. cruzi, a cooperation effect among the subpopulations should be considered.


Subject(s)
Life Cycle Stages , Mice/parasitology , Rhodnius/parasitology , Trypanosoma cruzi/growth & development , Animals , Host-Parasite Interactions , Opossums
7.
Parasitology ; 118 ( Pt 2): 161-6, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10028530

ABSTRACT

American trypanosamiasis occurs in nature as a sylvatic cycle, where Trypanosoma cruzi interacts with wild triatomines and mammalian reservoirs, such as marsupials, rodents, armadillos and other animals. Due to difficulties in trying to isolate T. cruzi stocks from the sylvatic cycle, very few studies have been performed in order to understand the parasite infection in natural environments. Traditionally T. cruzi has been considered to be composed of a highly heterogeneous population of parasites. In contrast, the mini-exon and the 24S alpha rRNA gene loci have shown that T. cruzi stocks can be clustered in 2 major phylogenetic groups: lineage 1 and lineage 2. In this report, 68 recently isolated T. cruzi samples from the sylvatic cycle belonging to different geographical areas in Rio de Janeiro, Brazil, have been typed based on a variable spot in the non-transcribed spacer of the mini-exon gene. Eight isolates were from triatomines, 26 stocks were from golden-lion tamarins, 31 from opossums, 2 from rodents and 1 from a three-toed sloth. Thirty (44%-30/68) isolates were typed as lineage 1, while 36 (53%-36/68) isolates were typed as lineage 2. Two opossums presented mixed infection. Therefore, 3% (2/68) of the isolates were typed as lineage 1 + lineage 2. Using these geographical regions as models of sylvatic environments, it was observed that 96% of the Didelphis marsupialis were infected by lineage 2 isolates, while all 26 golden-lion tamarins were infected by lineage 1. The results show preferential association of the 2 lineages of T. cruzi with different hosts, composing the complexity of the sylvatic cycle.


Subject(s)
Chagas Disease/parasitology , Trypanosoma cruzi , Animals , Brazil/epidemiology , Chagas Disease/epidemiology , Chagas Disease/veterinary , DNA, Protozoan/genetics , DNA, Ribosomal/genetics , Exons/genetics , Genes, Protozoan , Genetics, Population , Insect Vectors/parasitology , Mammals/parasitology , Marsupialia/parasitology , Mice , Phylogeny , RNA, Ribosomal/genetics , Rhodnius/parasitology , Saguinus/parasitology , Triatoma/parasitology , Trypanosoma cruzi/classification , Trypanosoma cruzi/genetics , Trypanosoma cruzi/growth & development
10.
Int J Parasitol ; 28(1): 105-12, 1998 Jan.
Article in English | MEDLINE | ID: mdl-9504338

ABSTRACT

American trypanosomiasis is transmitted in nature via a sylvatic cycle, where Trypanosoma cruzi interacts with wild triatomines and mammalian reservoirs, or via a domestic cycle where the parasite comes into contact with humans through domiciliated triatomines. The pool of T. cruzi isolates consists of sub-populations presenting a broad genetic diversity. In contrast to the heterogeneity suggested by isoenzyme analysis, PCR amplification of sequences from the 24S alpha rRNA gene and from the non-transcribed spacer of the mini-exon gene indicated dimorphism among T. cruzi isolates, which enabled the definition of two major parasite lineages. In the present study, 157 T. cruzi isolates obtained from humans, triatomines and sylvatic mammalian reservoirs from 12 Brazilian states were analysed by the 24S alpha RNA and mini-exon typing approaches. The stocks were classified into the two proposed lineages and according to the domestic or sylvatic cycle of the parasite. Data presented provide evidence for a strong association of T. cruzi lineage 1 with the domestic cycle, while in the sylvatic cycle both lineages circulate equally. Molecular typing of human parasite isolates from three well-characterised endemic regions of Chagas disease (Minas Gerais, Paraiba and Piaui) and from Amazonas State, where T. cruzi is enzootic, suggests that in some endemic areas in Brazil there is a preferential linkage between both cycles mediated by lineage-1 stocks.


Subject(s)
Chagas Disease/epidemiology , Genes, Protozoan , RNA, Ribosomal/genetics , Trypanosoma cruzi/genetics , Animals , Brazil/epidemiology , Chagas Disease/transmission , Exons , Humans , Mammals , RNA, Protozoan/genetics , Trypanosoma cruzi/isolation & purification
11.
Mem. Inst. Oswaldo Cruz ; 86(1): 73-9, jan.-mar. 1991. ilus, tab
Article in English | LILACS | ID: lil-109266

ABSTRACT

A trypanosome strain isolated from a sylvatic rodent (Echimys dasythrix) from Santa Catarina Island (Santa Catarina State, Brazil) was characterized by the following methods: experimental transmission and development in invertebrate hosts, morphometry, cross protection, complement sensitivity, lectin agglutination and isoenzyme profiles. Comparasions were made with standard Trypanosoma cruzi and T. rangeli strains. All methods except isoenzyne analysis led to the identification of the isolate as T. rangeli. The isoenzyme differences found could be explained on the basis of polymorphism. Therefore this is the first report of T. rangeli in southern Brazil, increasing the geographical distribution of this parasite


Subject(s)
Animals , Rodentia/parasitology , Trypanosoma/physiology , Disease Vectors , Isoenzymes/analysis , Host-Parasite Interactions , Trypanosoma/enzymology , Trypanosomiasis/transmission
12.
Mem Inst Oswaldo Cruz ; 86(1): 73-9, 1991.
Article in English | MEDLINE | ID: mdl-1842404

ABSTRACT

A trypanosome strain isolated from a sylvatic rodent (Echimys dasythrix) from Santa Catarina Island (Santa Catarina State, Brazil) was characterized by the following methods: experimental transmission and development in invertebrate and vertebrate hosts, morphometry, cross protection, complement sensitivity, lectin agglutination and isoenzyme profiles. Comparisons were made with standard Trypanosoma cruzi and T. rangeli strains. All methods except isoenzyme analysis led to the identification of the isolate as T. rangeli. The isoenzyme differences found could be explained on the basis of polymorphism. Therefore this is the first report of T. rangeli in southern Brazil, increasing the geographical distribution of this parasite.


Subject(s)
Rodentia/parasitology , Trypanosoma/isolation & purification , Animals , Brazil , Disease Vectors , Host-Parasite Interactions , Isoenzymes/analysis , Mice , Trypanosoma/enzymology , Trypanosoma/physiology , Trypanosomiasis/transmission
13.
Mem Inst Oswaldo Cruz ; 79(4): 495-7, 1984.
Article in English | MEDLINE | ID: mdl-6442752

ABSTRACT

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.


Subject(s)
Chagas Disease/parasitology , Trypanosoma cruzi/isolation & purification , Animals , Female , Mice , Trypanosoma cruzi/pathogenicity
14.
Mem. Inst. Oswaldo Cruz ; 79(4): 495-7, 1984.
Article in English | LILACS | ID: lil-22812

ABSTRACT

De uma infeccao inicialmente dupla em camundongo, estabelecida por inoculo simultaneo e equivalente de formas sanguineas das cepas Y e F de Trypanosoma cruzi, duas linhagens foram originadas por subinoculacoes: uma (W) passada casa semana, a outra (M) cada mes. Por metodos biologicos e bioquimicos 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 selecao de cepas atraves de manipulacao em laboratorio de populacoes inicialmente mistas de T. cruzi


Subject(s)
Female , Animals , Mice , Chagas Disease , Trypanosoma cruzi
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