| dc.description.abstract | Fifty-six Trypanosoma cruzi stocks from Chile and neighboring countries and different hosts, humans, and
Triatoma infestans and Mepraia sp., vectors of domiciliary and natural environments were characterized by using
three molecular markers. These were cytochrome b (Cyt b) gene sequencing, minicircle DNA blotting, and
hybridization with five genotype-specific DNA probes and nuclear analysis of 1f8 and gp72 by polymerase chain
reaction–restriction fragment length polymorphism. The results with all three molecular markers are concordant,
with minor limitations, grouping T. cruzi stocks into four discrete typing units (DTUs) (TcI, TcII, TcV, and TcVI).
TcI and TcII stocks were heterogeneous. TcI and TcII stocks were clustered in two main subgroups determined
by Cyt b gene sequencing and minicircle hybridization. However, TcV and TcVI stocks were homogeneous and
not differentiated by Cyt b gene sequencing or minicircle DNA hybridization. The discriminatory power and
limitations of the molecular markers are discussed, as well as the distribution of the four DTUs in the domiciliary
and sylvatic transmission cycles of Chile and the limitations of each marker for molecular epidemiological
studies performed with T. cruzi stocks rather than the analysis of direct T. cruzi samples from natural hosts. | |
