Trypanosoma cruzi strains isolated from human, vector, and animal reservoir in the same endemic region in Mexico and typed as T. cruzi I, discrete typing unit 1 exhibit considerable biological diversity.
In this study, three strains of Trypanosoma cruzi were isolated at the same time and in the same endemic region in Mexico from a human patient with chronic chagasic cardiomyopathy (RyC-H); vector (Triatoma barberi) (RyC-V); and rodent reservoir (Peromyscus peromyscus) (RyC-R). The three strains were characterized by multilocus enzyme electrophoresis, random amplified polymorphic DNA, and by pathological profiles in experimental animals (biodemes). Based on the analysis of genetic markers the three parasite strains were typed as belonging to T. cruzi I major group, discrete typing unit 1. The pathological profile of RyC-H and RyC-V strains indicated medium virulence and low mortality and, accordingly, the strains should be considered as belonging to biodeme Type III. On the other hand, the parasites from RyC-R strain induced more severe inflammatory processes and high mortality (> 40%) and were considered as belonging to biodeme Type II. The relationship between genotypes and biological characteristics in T. cruzi strains is still debated and not clearly understood. An expert committee recommended in 1999 that Biodeme Type III would correspond to T. cruzi I group, whereas Biodeme Type II, to T. cruzi II group. Our findings suggest that, at least for Mexican isolates, this correlation does not stand and that biological characteristics such as pathogenicity and virulence could be determined by factors different from those identified in the genotypic characterization.
Sánchez-Guillén
María del Carmen
Mdel C
Laboratorio de Fisiopatología de Enfermedades Crónicas, Centro de Investigación Biomédica de Oriente, Instituto Mexicano del Seguro Social, Atlixco, Puebla, México.
Bernabé
Christian
C
Tibayrenc
Michel
M
Zavala-Castro
Jorge
J
Totolhua
José-Luis
JL
Méndez-López
Julio
J
González-Mejía
Martha-Elba
ME
Torres-Rasgado
Enrique
E
López-Colombo
Aurelio
A
Pérez-Fuentes
Ricardo
R
D000818:Animals; D014355:Chagas Disease / Q000469:parasitology* / Q000473:pathology; D004195:Disease Models, Animal; D004587:Electrophoresis, Agar Gel; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008800:Mexico; D051379:Mice; D008807:Mice, Inbred BALB C; D018512:Parasitemia / Q000469:parasitology* / Q000473:pathology; D010542:Peromyscus; D019105:Random Amplified Polymorphic DNA Technique; D014224:Triatoma; D014349:Trypanosoma cruzi / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D014774:Virulence