Expanding the knowledge of the geographic distribution of Trypanosoma cruzi TcII and TcV/TcVI genotypes in the Brazilian Amazon

PLoS One. 2014 Dec 31;9(12):e116137. doi: 10.1371/journal.pone.0116137. eCollection 2014.

Abstract

Trypanosoma cruzi infection is a complex sylvatic enzooty involving a wide range of animal species. Six discrete typing units (DTUs) of T. cruzi, named TcI to TcVI, are currently recognized. One unanswered question concerning the epidemiology of T. cruzi is the distribution pattern of TcII and hybrid DTUs in nature, including their virtual absence in the Brazilian Amazon, the current endemic area of Chagas disease in Brazil. Herein, we characterized biological samples that were collected in previous epizootiological studies carried out in the Amazon Basin in Brazil. We performed T. cruzi genotyping using four polymorphic genes to identify T. cruzi DTUs: mini-exon, 1f8, histone 3 and gp72. This analysis was conducted in the following biological samples: (i) two T. cruzi isolates obtained by culturing of stools from the triatomine species Rhodnius picttipes and (ii) five serum samples from dogs in which trypomastigotes were observed during fresh blood examination. We report for the first time the presence of TcII and hybrid DTUs (TcV/TcVI) in the Amazon region in mixed infections with TcI. Furthermore, sequencing of the constitutive gene, gp72, demonstrated diversity in TcII even within the same forest fragment. These data show that TcII is distributed in the five main Brazilian biomes and is likely more prevalent than currently described. It is very probable that there is no biological or ecological barrier to the transmission and establishment of any DTU in any biome in Brazil.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Brazil / epidemiology
  • Chagas Disease / epidemiology
  • Chagas Disease / parasitology
  • DNA, Protozoan / genetics
  • Dog Diseases / parasitology
  • Dogs / parasitology*
  • Genetic Variation
  • Genotype
  • Geography
  • Phosphoproteins / genetics
  • Protozoan Proteins / genetics
  • Rhodnius / parasitology*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Trypanosoma cruzi / classification*
  • Trypanosoma cruzi / genetics*
  • Trypanosoma cruzi / isolation & purification

Substances

  • DNA, Protozoan
  • GP72 antigen, Trypanosoma
  • Phosphoproteins
  • Protozoan Proteins

Grants and funding

This study was funded by Fundação Oswaldo Cruz - FIOCRUZ; the European Union Seventh Framework Program Grant 223034 – ChagasEpiNet; Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ). All isolates in the present study originated from ColTryp/IOC-FIOCRUZ. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.