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

Abstract

Introducción. T. cruzi I y T. cruzi II son grupos genéticamente diferentes y se cree que dicha variabilidad es determinante del tropismo tisular en el hospedero vertebrado y responsable de las diversas manifestaciones clínicas de la enfermedad de Chagas. Objetivo. Caracterizar biológica y genéticamente dos clones colombianos de los grupos T. cruzi I y II en el modelo murino. Materiales y métodos. Las cepas CAS15 y AF1 pertenecientes a los grupos T. cruzi I y II fueron clonadas en medio semisólido. Un clon de cada una de ellas y una mezcla de ambos se utilizaron para infectar ratones, los cuales se sacrificaron a diferentes tiempos post-infección. Para analizar la presencia del parásito en sangre y diferentes órganos, se utilizaron el microhematocrito y la reacción en cadena de la polimerasa con los marcadores de la secuencia satélite del ADN nuclear y con el espaciador intergénico del gen mini-exón. Resultados. El clon T. cruzi I fue más infectivo, observándose un tropismo preferencial por corazón, recto y músculo esquelético, mientras que el clon T. cruzi II presentó un tropismo preferencial por bazo e hígado. Durante la infección con la mezcla de los clones, se observó que el clon T. cruzi I predominó sobre el T. cruzi II tanto en sangre como en órganos. Conclusiones. Los resultados confirman que las diferencias genéticas entre los grupos de T. cruzi podrían estar determinando el tropismo tisular y de esta manera jugar un papel fundamental en el entendimiento de las manifestaciones clínicas de la enfermedad de Chagas en Colombia.Palabras claves: Trypanosoma cruzi, enfermedad de Chagas, variación (Genética), tropismo. Biological and genetic characterization of two Colombian clones of Trypanosoma cruzi groups I and IIIntroduction. Genetic differences between T. cruzi I and T. cruzi II may determine differences in their tissue tropism in the vertebrate host and may also be responsible for the differences in clinical manifestations of Chagas disease. Objective. Two Colombian clones of the T. cruzi groups I and II were characterized biologically and genetically in a murine model. Materials and methods. Strains Cas15 and AF1 belonging to the T. cruzi groups I and II were cloned in semisolid medium. A clone of each strain and a mix of both were used to infect mice; the mice were subsequently sacrificed at selected post-infection intervals. In order to identify the parasite presence in blood and organs, two methods were used (a) microhematocrit and (b) polymerase chain reaction with primers for satellite DNA and the intergenic region of miniexon. Results. The T. cruzi I clone was more infectious, with a preferential tropism observed in heart, rectum and skeletal muscle, whereas clone T. cruzi II exhibited a preferential tropism for spleen and liver. During the infection with the clone mixture a predominance of the T. cruzi I clone over clone II in blood as well as in organs was observed. Conclusion. The results corroborate that the genetic differences between the T. cruzi groups correlate with their tissue tropism, an...

Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula

“…All samples positive for T. cruzi using S34/S67 kDNA were amplified using the inter-genic region of the mini-exon gene to identify lineage type (Fernándes et al, 1998;Botero et al, 2007). A volume of 1.5 µl of the total 80 µl DNA from T. cruzi positive samples from mammals or triatomines was used as template for a final volume of 25 µl, with 1x Master mix, (Taq polymerase in a 200 mM buffer at pH 8.5 of each dNTP and 1.5 mM MgCl (Promega Corporation, Madison, Wisconsin, USA), and 10µM of each primer.…”

Infestación por triatominos en comunidades indígenas de Valledupar, Colombia

“…c In considering the careful follow-up of parasite cultures, the T. cruzi clones that produced the histopathological traits are the same that grew in the culture media. Nonetheless, there is a possibility that post-inoculation clonal selection of T. cruzi may have occurred, a process described by Botero et al 4 as the result of the host immune system, in this case ICR mice.…”

“…Residents of these regions were not reached by vector control programs since 2007 and have not received therapeutic treatment due to particular cultural conditions. 2,4,23 At the end of the 1990s, the Program for Control of Trypanosoma cruzi Transmission and Child Cardiomyopathy in the main Endemic Areas of Colombia was initiated, including in Cesar and Guajira Departments. The goal was to determine priority indices for municipal attention.…”

Geographical clustering of Trypanosoma cruzi I groups from Colombia revealed by low-stringency single specific primer-PCR of the intergenic regions of spliced-leader genes

“…cruzi cloning One isolate from the Momposina Depression within the Magdalena department (Sebas16) was used to obtain clones after culture in agar-LIT-brain heart infusion (BHI)-blood as described elsewhere (Botero et al 2007): 50 mL of sterile agar pH 7.2, 100 mL LIT with bovine faetal serum (BFS) 10%, 100 mL BHI and 6.25 mL defibrinated blood. Forty epimastigote cells were loaded per petri dish and cultured at 28°C to detect growth of transparent puntiform colonies after around 30 days.…”