Repetitive sequences in the ribosomal intergenic spacer of Trypanosoma cruzi

Novak, Estela Maria; Mello, Maricilda Palandi de; Gomes, Henrique B.M.; Galindo, Iván; Guevara, Palmira; Ramirez, JoséL.; Silveira, JoséFranco da

doi:10.1016/0166-6851(93)90138-n

Cited by 28 publications

(12 citation statements)

References 26 publications

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“…These primers target sequence-repeated elements within the T. cruzi nontranscribed ribosomal spacer. 19 The assay detected all T. cruzi isolates, but did not react with T. rangeli, other kinetoplastida, or human DNA. 19,20 The reaction was done in a total volume of 50 l containing l mM of each DNTP, 200 mM of each primer; one unit of Taq DNA polymerase in 1ϫ reaction buffer (10 m MTris-HCI, pH 8.3, 50 mM KCl, 100 mg/ml of gelatin).…”

Section: Methodsmentioning

confidence: 99%

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Myocardial parasite persistence in chronic chagasic patients.

Áñez¹,

Carrasco²,

Parada³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

132

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Abstract. The persistence of Trypanosoma cruzi tissue forms was detected in the myocardium of seropositive individuals clinically diagnosed as chronic chagasic patients following endomyocardial biopsies (EMBs) processed by immunohistochemical (peroxidase-anti-peroxidase [PAP] staining) and molecular (polymerase chain reaction [PCR]) techniques. An indirect immunofluorescent technique revealed antigenic deposits in the cardiac tissue in 24 (88.9%) of 27 patients. Persistent T. cruzi amastigotes were detected by PAP staining in the myocardium of 22 (84.6%) of 26 patients. This finding was confirmed with a PCR assay specific for T. cruzi in 21 (91.3%) of 23 biopsy specimens from the same patients. Statistical analysis revealed substantial agreement between PCR and PAP techniques (k ϭ 0.68) and the PCR and any serologic test (k ϭ 0.77). The histopathologic study of EMB specimens from these patients revealed necrosis, inflammatory infiltrates, and fibrosis, and made it possible to detect heart abnormalities not detected by electrocardiogram and/or cineventriculogram. These indications of myocarditis were supported by the detection of T. cruzi amastigotes by the PAP technique or its genome by PCR. They suggest that although the number of parasites is low in patients with chronic Chagas' disease, their potential for heart damage may be comparable with those present during the acute phase. The urgent necessity for testing new drugs with long-term effects on T. cruzi is discussed in the context of the present results.

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Section: Methodsmentioning

confidence: 99%

“…This plasmid is a subclone of recombinant bacteriophage 4a1 isolated from a genomic library of T. cruzi isolate G. 19 Trypanosoma cruzi CL Brener purified DNA 21 was used as a positive control for the PCR.…”

Section: Methodsmentioning

confidence: 99%

Myocardial parasite persistence in chronic chagasic patients.

Áñez¹,

Carrasco²,

Parada³

et al. 1999

The American Journal of Tropical Medicine and Hygiene

132

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“…Conditions for amplification and hybridization have been previously described. 5,6 Statistical analysis. This consisted of a comparison of PCR as the gold standard test and the DAT, IFAT, and ELISA as alternative tests in people from endemic areas for Chagas disease in western Venezuela.…”

Section: Patientsmentioning

confidence: 99%

Detection and significance of inapparent infection in Chagas disease in western Venezuela.

Áñez

Crisante²,

Rojas³

et al. 2001

The American Journal of Tropical Medicine and Hygiene

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Abstract. Inapparent infections of Trypanosoma cruzi were detected in symptomless seropositive people living in close proximity, and under the same conditions of risk, to patients with acute Chagas disease. Similar infections were also detected in sera samples of people from 25 villages of western Venezuela where Chagas disease is endemic. Seropositivity in all the 1,251 studied samples was established by use of 3 serological methods (direct agglutination test, indirect immunofluorescence antibody test, and enzyme-linked immunosorbent assay). Each seropositive sample was tested for detection of anti-T. cruzi-specific immunoglobulin (Ig) M and IgG levels and specific T. cruzi infection by molecular methodology (polymerase chain reaction assay). The combined analysis of the serologic (IgM and IgG levels), molecular (specific T. cruzi DNA), and statistical findings demonstrated the existence of a different stage of T. cruzi infection in asymptomatic patients, which is suggested to be recognized as inapparent infection. Its definition, significance, and comparison with typical Chagas disease phases are presented, and its potential epidemiological importance is discussed.

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“…This fragment, which seems to be associated with the length polymorphism in the H. indica IGS region, is the basis of the D1/D1a polymorphism observed by Curran and Driver (1994). In most species studied to date, the rDNA IGS contains tandem arrays of subrepeats (Gerbi, 1985;Williams et al, 1990;Vahidi & Honda, 1991;Novak et al, 1993;Linares et al, 1994;Crease, 1995). This results in the length of the IGS region being variable both between and within species.…”

Section: Discussionmentioning

confidence: 99%

Molecular characterisation of Heterorhabditis indica isolates from India, Kenya, Indonesia and Cuba

Stack

Easwaramoorthy

Metha

et al. 2000

Nematol

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Summary -Isolates of Heterorhabditis were identi ed as H. indica using the following molecular diagnostic features: hybridisation to a H. indica speci c satellite DNA probe; AluI and MboI restriction pro les of the rDNA ITS PCR product and the AluI pro le of the rDNA IGS PCR product. The Kenyan isolates represent a distinct subgroup of H. indica. These isolates lacked one of the two Hinf I restriction sites which are present in the rDNA ITS product of all the other isolates tested and they also differed from other H. indica isolates in their rDNA IGS HaeIII restriction pro le. The Indian isolates are interfertile. The Kenyan isolates are interfertile but only one Kenyan isolate, Ki3, produced viable progeny when crossed with H. indica LN2. The four Indonesian isolates are interfertile, but only one Indonesian isolate (INA H1) produced viable hybrids when crossed with H. indica LN2. INA H1 was also interfertile with the Kenyan isolate Ki3. Résumé -Caractérisation moléculaire d'isolats d'Heterorhabditis indica provenant d'Inde, du Kenya, d'Indonésie et de Cuba -Des isolats d'Heterorhabditis ont été identi és comme H. indica par l'utilisation des techniques de caractérisation moléculaire suivantes: hybridation avec une sonde spéci que du DNA satellite de H. indica, produits des pro ls de restriction par PCR de l'ITS du rDNA par AluI et MboI et produit de PCR de l'IGS du rDNA par AluI. Les isolats keniyans constituent un sous-groupe distinct d' H. indica. Un des deux sites de restriction de Hinf I, présent dans les produits de l'ITS du rDNA de tous les autres isolats étudiés, est absent dans ces isolats qui différaient également dans leurs pro ls de restriction de l'IGS du rDNA par HaeIII. Les isolats d'Inde sont interfertiles. Les isolats kenyans sont inter-fertiles mais un seul de ces isolats, Ki3, a produit une descendance viable après croisement avec H. indica LN2. Les quatre isolats indonésiens sont interfertiles, mais un seul d'entre eux (INA H1) a produit des hybrides viables après croisement avec H. indica LN2. INA H1 a été également interfertile avec l'isolat kenyan Ki3.

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Repetitive sequences in the ribosomal intergenic spacer of Trypanosoma cruzi

Cited by 28 publications

References 26 publications

Myocardial parasite persistence in chronic chagasic patients.

Myocardial parasite persistence in chronic chagasic patients.

Detection and significance of inapparent infection in Chagas disease in western Venezuela.

Molecular characterisation of Heterorhabditis indica isolates from India, Kenya, Indonesia and Cuba

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