Sylvatic Triatoma infestans (Hemiptera: Reduviidae) from Argentina and Bolivia: nucleotide variation and phylogenetic relationships.

PICCINALI RV, CEBALLOS LA, NOIREAU F, KITRON U, GURTLER RE.

Punta del Este, Uruguay

Congreso; 150 years of Darwin’s Evolutionay theory. A South American celebration; 2009

Triatoma infestans is the main vector of the flagellate protozoan Trypanosoma cruzi, the agent of Chagas Disease in several Southamerican countries. T. infestans is mostly a domestic or peridomestic species, but recent studies suggest the presence of several sylvatic foci in Argentina and Bolivia. These populations have epidemiologic relevance because they could act as reinfestation sources after residual insecticide spraying. A fragment of the mitochondrial gene COI and the nuclear region ITS-1 was sequenced in bugs from sylvatic foci in Chaco, Argentina and Cochabamba, Bolivia. Nucleotide and haplotype variability was estimated and phylogenetic relationships were reconstructed with maximum parsimony and Bayesian approaches.The Argentinean population was the more variable both for nucleotide and haplotype variability. Phylogenetic analyses showed that several Argentinean haplotypes diverge early in the topologies while the remaining Argentinean variants clustered in one clade and all the Bolivian sequences in another. These results are in agreement with: a) A great genetic differentiation between sylvatic bugs from Argentina and Bolivia, b) Sylvatic bugs from Argentina could belong to an ancient population, in contraposition with the traditional hypothesis that the Bolivian Andean Valleys are the area of origin of T. infestans.