Acta Parasitologica, Vol. 52, No. 1, 2007, 74-81. DOI: 10.2478/s11686-007-0005-4 Fernanda L. Spitzner (1), Jorge M. de Freitas (2), Andréa M. Macedo (2), Max J. de Ornelas Toledo (1),
Silvana M. de Araújo (1), Alberto J. Prioli (3) and Mônica L. Gomes (1)* - Trypanosoma cruzi-triatomine associations and the presence of mixed infections in single triatomine bugs in Paraná state, Brazil
(1) Departamento de Análises Clínicas, Laboratório de Parasitologia Básica, Bloco I-90, Universidade Estadual de Maringá, Av. Colombo,
5790, 87020-900, C.P. 331, Maringá, Paraná;
(2) Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade
Federal de Minas Gerais, Minas Gerais;
(3) Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá; Brazil
*Corresponding author: mlgomes@uem.br
ABSTRACT
Eighteen strains of Trypanosoma cruzi isolated from two species of triatomines in the state of Parana, Brazil, were characterized
molecularly using three strategies: RAPD (randomly amplified polymorphic DNA) with four primers, analysis of the D7
polymorphic region of the 24Sα rDNA, and RFLP (restriction fragment length polymorphism) of region 5' of the mitochondrial
gene COII (cytochrome oxidase subunit 2). The phenogram constructed with the RAPD data showed that only three strains isolated
from Panstrongylus megistus collected in the Municipality of Arapongas were grouped together in a sub-branch. None of
the other 15 strains could be clustered according to triatomine species or geographical origin. The strains were grouped with the
T. cruzi I reference sample, indicating closer association with the sylvatic transmission cycle of T. cruzi in the state of Paraná.
However, analyses of the rDNA and COII gene polymorphisms revealed the presence of populations from both T. cruzi I and II
major lineages. In half of the analyzed triatomines, we found parasites from both lineages coinfecting the same bugs. Of these,
most (6/9) were isolated from Triatoma sordida, and 3/9 from Panstrongylus megistus. These results contribute to a better comprehension
of the ecoepidemiology of Chagas. disease in Parana, and raise questions about the role of studies of polyclonal population
dynamics for controlling the transmission of T. cruzi to humans in this region.
KEY WORDS: Trypanosoma cruzi, triatomines, RAPD, rDNA, mitochondrial DNA