Trypanosoma cruzi III causing the indeterminate form of Chagas disease in a semi-arid region of Brazil.
OBJECTIVE
Trypanosoma cruzi is subdivided into six discrete typing units (DTUs), TcI-TcVI. The precise identification of each can contribute to tracking wild DTUs that invade the domiciliary environment.


METHODS
Twenty T. cruzi stocks isolated from 16 chagasic patients, two Panstrongylus lutzi, one Galea spixii, and one Euphractus sexcinctus, from different localities in the State of Rio Grande do Norte, Brazil, were characterized by genotyping the 3' region of the 24Sα rRNA gene, the mitochondrial cytochrome oxidase subunit 2 gene, and the spliced leader intergenic region.


RESULTS
TcIII was identified in 18.7% (3/16) of patients from different municipalities, as well as in P. lutzi, G. spixii, and E. sexcinctus, indicating the connection between the sylvatic and domestic cycles in this Brazilian semi-arid region. TcI and TcII were also detected, in 37.5% (6/16) and 43.8% (7/16) of patients, respectively. These DTUs were associated with cardiac, digestive, and indeterminate clinical forms, while TcIII was identified only in patients with the indeterminate form.


CONCLUSIONS
The occurrence of these DTUs reveals important phylogenetic diversity in T. cruzi isolates from humans. TcIII is reported for the first time in northeastern Brazil. These findings appear to indicate an overlap between the sylvatic and domestic transmission cycles of the parasite in this region.
Graduate Program in Pharmaceutical Sciences, Center for Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil.
Kiev
K
Martins
Graduate Program in Health Sciences/DINTER/UERN, Federal University of Rio Grande do Norte, Natal, Brazil.
Cléber de Mesquita
Cde M
Andrade
Graduate Program in Pharmaceutical Sciences, Center for Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil.
Andressa Noronha
AN
Barbosa-Silva
State Department of Public Health of Rio Grande do Norte, Caicó, Brazil.
Gerson Barbosa
GB
do Nascimento
Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Egler
E
Chiari
Graduate Program in Pharmaceutical Sciences, Center for Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil; Department of Parasitology, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Lúcia Maria da Cunha
LM
Galvão
Graduate Program in Pharmaceutical Sciences, Center for Health Sciences, Federal University of Rio Grande do Norte, Natal, Brazil; Department of Clinical and Toxicological Analyses, Center for Health Sciences, Federal University of Rio Grande do Norte, Rua Gal. Gustavo Cordeiro de Farias s/n 2° Andar Petrópolis, 59012-570 Natal, RN, Brazil. Electronic address: acjcamara@ufrnet.br.
Antonia Cláudia Jácome
AC
da Câmara
D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D014355:Chagas Disease / Q000453:epidemiology / Q000469:parasitology*; D002980:Climate; D005260:Female; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D010802:Phylogeny; D014349:Trypanosoma cruzi / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification
Chronic chagasic patients; Clinical forms; Discrete typing units; Genetic diversity; Trypanosoma cruzi