Homogeneity of Trypanosoma cruzi I, II, and III populations and the overlap of wild and domestic transmission cycles by Triatoma brasiliensis in northeastern Brazil

Parasitology Research - Tập 112 - Trang 1543-1550 - 2013
Antonia Cláudia Jácome da Câmara1,2, Eliane Lages-Silva3, George Harisson Felinto Sampaio2, Daniella Alchaar D’Ávila4, Egler Chiari4, Lúcia Maria da Cunha Galvão2,5
1Departamento de Análises Clínicas e Toxicológicas, Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, Brazil
2Programa de Pós-Graduação em Ciências Farmacêuticas, Centro de Ciências da Saúde, Universidade Federal do Rio Grande do Norte, Natal, Brazil
3Departamento de Imunologia, Microbiologia e Parasitologia, Instituto de Ciências Biológicas e Naturais, Universidade Federal do Triângulo Mineiro, Uberaba, Brazil
4Laboratorio de Biologia do Trypanosoma cruzi e doença de Chagas, Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
5Programa de Pós-Graduação em Ciências Farmacêuticas, (Pesquisador Visitante/CNPq) Universidade Federal do Rio Grande do Norte Centro de Ciências da Saúde, Natal, Brazil

Tóm tắt

The genetic variability of 24 Trypanosoma cruzi isolates from humans (11) and triatomines (13) in northeastern Brazil was analyzed by random amplified polymorphic DNA (RAPD) and compared with taxonomic groups, host, and geographical origin of the parasite. TcI (12.5 %), TcII (45.8 %), and TcIII (41.6 %) showed a similarity coefficient (SC) of 0.74 using the mean of three primers and 0.80, 0.75, and 0.66 for λgt11-F, M13-40F, and L15996 primers, respectively. The samples were clustered according to their phylogenetic origin in two polymorphic and divergent branches: one associated with TcI and the other with two subbranches corresponding to TcII and TcIII. TcI was only identified in humans and correlated with the Id homogenous group (0.80 SC). TcII from humans and Triatoma brasiliensis showed 0.86 SC and was clustered according monoclonal or polyclonal populations with similar RAPD profiles detected among the vector and/or humans in different municipalities. TcIII was isolated exclusively in sylvatic cycles from T. brasiliensis and Panstrongylus lutzi and showed low variability (0.84 SC) and high homology mainly among isolated populations at the same locality. The homology of T. cruzi among different hosts and locations suggests the distribution of principal clones circulating and reveals an overlapping between the sylvatic and domestic cycles in this area, where T. brasiliensis infected with TcII acts as link in both environments. This species is important to maintain TcII and TcIII in wild cycles and deserves particular attention due an emergent risk of these populations being introduced into the domestic cycle; moreover, its clinical and epidemiological implications remain unknown.

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