Molecular characterization of Trypanosoma cruzi Mexican strains and their behavior in the mouse experimental model

Abstract

Introduction: For a long time, the importance of Chagas disease in Mexico, where many regarded it as an exotic malady, was questioned. Considering the great genetic diversity among isolates of Trypanosoma cruzi, the importance of this biological characterization, and the paucity of information on the clinical and biological aspects of Chagas disease in Mexico, this study aimed to identify the molecular and biological characterization of Trypanosoma cruzi isolates from different endemic areas of this country, especially of the State of Jalisco. Methods: Eight Mexican Trypanosoma cruzi strains were biologically and genetically characterized (PCR specific for Trypanosoma cruzi, multiplex-PCR, amplification of space no transcript of the genes of the mini-exon, amplification of polymorphic regions of the mini-exon, classification by amplification of intergenic regions of the spliced leader genes, RAPD -(random amplified polymorphic DNA). Results: Two profiles of parasitaemia were observed, patent (peak parasitaemia of 4.6×10 6 to 10 7 parasites/mL) and subpatent. In addition, all isolates were able to infect 100% of the animals. The isolates mainly displayed tropism for striated (cardiac and skeletal) muscle. PCR amplification of the mini-exon gene classified the eight strains as TcI. The RAPD technique revealed intraspecies variation among isolates, distinguishing strains isolated from humans and triatomines and according to geographic origin. Conclusions: The Mexican T. cruzi strains are myotrophic and belong to group TcI. Keywords: Trypanosoma cruzi. Mexico. Biological characterization. Genetic characterization. RESUMOIntrodução: Durante muito tempo, foi questionada a importância da doença de Chagas no México onde muitos a consideravam um padecimento exótico. Considerando a grande diversidade genética existente, entre os isolados de Trypanosoma cruzi, a importância da caracterização biológica desses e o escasso número de informações sobre os aspectos clínicos e biológicos da doença de Chagas no México, o objetivo deste trabalho foi realizar a caracterização biológica e molecular de isolados de Trypanosoma cruzi originários de diferentes áreas endêmicas deste país, principalmente do Estado de Jalisco. Métodos: Oito cepas mexicanas de Trypanosoma cruzi foram caracterizadas biologicamente e geneticamente (PCR específica para Trypanosoma cruzi, PCR-multiplex, amplificação do espaço não transcrito dos genes do mini-exon, amplificação das regiões polimórficas do gene do mini-exon, classificação pela amplificação de regiões intergênicas dos genes do spliced leader, RAPD -random amplified polymorphic DNA). Resultados: Foram observados dois tipos de parasitemia: patente com picos máximos de parasitemia entre 4,6x10 6 e 10 7 parasitas/mL e subpatente. Além disso, todos os isolados foram capazes de infectar 100% dos animais. Observou-se tropismo predominante pelo músculo estriado (cardíaco e esquelético). As técnicas de PCR do gene do mini-éxon classificaram as oito cepas como TcI e a técnica de RAPD mostrou variaçã...

Presence of Virginia opossum (Didelphis virginiana) and Pic (Triatoma dimidiata) infected with Trypanosoma cruzi in urban areas: preliminary evaluation in the city of Campeche, Mexico

“…The predominance of T. cruzi Lineage I in Mexico is not limited to just marsupials; it has also being found in humans and vectors (Ruíz-Sánchez et al 2005, Gómez-Hernández et al 2011. Our findings contrast with those from South American countries were T. cruzi lineage II is the main genotype associated with human infections (domestic cycle) (Bosseno et al 2002).…”

Microsatellite and Mini-Exon Analysis of Mexican Human DTU ITrypanosoma cruziStrains and Their Susceptibility to Nifurtimox and Benznidazole

“…In Mexico, most T. cruzi strains have been genetically determined to belong to TcI (Bosseno et al 2002, Leó n-Pérez et al 2007, Gó mez-Hernández et al 2011 and TcII-TcVI strains have been reported only in a recent serological study, in wild mammals and the feces of vectors (Ló pez-Olmos et al 1998, Bosseno et al 2009, Risso et al 2011. In this work, we confirmed that the Mexican T. cruzi strains isolated from humans belonged to TcI, as reported in Guatemala, Colombia, and Venezuela (Añ ez et al 2004, Ruíz-Sánchez et al 2005, Falla et al 2009).…”

Putting Infection Dynamics at the Heart of Chagas Disease

“…The broad range of infected organs was noted in the earliest autopsy studies of fatal acute T. cruzi infection [40]. Analyses of acutely infected mice have shown that diverse parasite strains indeed infect a huge array of cell types in virtually any tissue [16, 20-22, 26, 33, 41-47]. However, the relative abundance of parasites in different cell or tissue types varies greatly.…”