Genetic Characterization of Trypanosoma cruzi Directly from Tissues of Patients with Chronic Chagas Disease

Abstract

We have previously shown that a low-stringency single-specific primer-polymerase chain reaction (LSSP- PCR) is a highly sensitive and reproducible technique for the genetic profiling of Trypanosoma cruzi parasites directly in tissues from infected animals and humans. By applying LSSP-PCR to the study of the variable region of kinetoplast minicircle from T. cruzi, the intraspecific polymorphism of the kinetoplast-deoxyribonucleic acid (kDNA) sequence can be translated into individual kDNA signatures. In the present article, we report on our success using the LSSP-PCR technique in profiling the T. cruzi parasites present in the hearts of 13 patients with chagasic cardiopathy and in the esophagi of four patients (three of them with chagasic megaesophagus). In two patients, one with the cardiodigestive clinical form of Chagas disease and the other with cardiopathy and an esophageal inflammatory process, we could study both heart and esophagus and we detected distinct kDNA signatures in the two organs. This provides evidence of a differential tissue distribution of genetically diverse T. cruzi populations in chronic Chagas disease, suggesting that the genetic variability of the parasite is one of the determining factors of the clinical form of the disease.

Trypanosoma cruzi persistence at oral inflammatory foci in chronic chagasic patients

“…However, the possibility that T. cruzi-DNA found in gingival inflammatory foci of the here study CCP may belong to a group of particular T. cruzi-clone with special affinity for this tissue, cannot be ignored. This statement finds support in previous work using LSSP-PCR to identify genespecific sequence polymorphisms and characterize T. cruzi directly from tissues of chagasic patients through specific molecular signatures (Pena et al, 1994;Vago et al, 1996Vago et al, , 2000. The detection of distinct T. cruzi signatures in different organs of the same chagasic patient (Vago et al, 2000) lead to the clonal histotropic model of Chagas disease (Macedo et al, 2004) a fact to be investigated in samples from gingival inflammatory foci of CCP.…”

The molecular epidemiology and phylogeography of Trypanosoma cruzi and parallel research on Leishmania: looking back and to the future

“…Ideally, the conundrum of whether infecting genotypes, as well as host factors, govern clinical manifestations (Carranza et al 2009) can be addressed, although this hope is yet to be fully realised and may require innovative technical approaches to reveal the T. cruzi genotypes present in blood and internal organs (Vago et al 2000 ;Valadares et al 2008) and to resolve the patient's prior history of exposure to such genotypes.…”

Caracterización biológica y genética de dos clones pertenecientes a los grupos I y II de Trypanosoma cruzi de Colombia

“…La enfermedad avanza a una fase crónica, caracterizada por baja parasitemia y un impredecible curso clínico que puede involucrar problemas cardiacos o gastrointestinales (4). En esta fase el parasitismo en tejidos es muy alto y restringido a algunos órganos como corazón, músculo esquelético, hígado, esófago, bazo y recto (5,6). La habilidad del parásito para sobrevivir a la fase aguda y avanzar hacia la fase crónica e invadir determinados órganos depende tanto de factores genéticos del parásito como del hospedero (7)(8)(9)(10)(11).…”