title: Genetic variability of Trypanosoma cruzi TcI isolates from rural and urban areas of Venezuela.
abstract: OBJECTIVE
  Several studies have demonstrated genetic heterogeneity in populations of Trypanosoma cruzi that allowed the identification of six different discrete typing units (DTU) classified as TcI, TcII, TcIII, TcIV, TcV and TcVI. Furthermore, some characterization studies have described genetic variability within TcI isolates from endemic regions. The objective of the present study was to analyze Venezuelan T. cruzi isolates, obtained from triatomine-vectors, mammal-hosts including infected humans, detected in both rural and urban areas from diverse geographic origins.
  
  
  METHODS
  Molecular characterization of 44 Venezuelan T. cruzi isolates, obtained from triatomine-vectors, mammalian hosts and human patients from both rural and urban areas of different geographic origins, were carried out. Samples were analyzed by PCR amplification of the intergenic region of the mini-exon gene, 24Sα rDNA and 18S rDNA, followed by sequencing of the amplification products.
  
  
  RESULTS
  The TcI amplification pattern was found in 42 out of 44 (95.5%) isolates; a TcIII strain and one possible TcIV were also found. The sequence analysis of the TcI Venezuelan isolates showed genetic variability among them. Urban isolates formed a homogeneous group, with differences in their sequences, when compared to rural isolates.
  
  
  CONCLUSIONS
  The results showed genetic heterogeneity in Venezuelan TcI strains, probably in response to different environmental conditions.
authors: María G
authors: MG
authors: Rivera
authors: Leidi
authors: L
authors: Herrera
authors: Antonio
authors: A
authors: Morocoima
authors: Cruz M
authors: CM
authors: Aguilar
authors: Teresa
authors: T
authors: Gárate
authors: Mariela
authors: M
authors: López
authors: María
authors: M
authors: Lares
authors: Mercedes
authors: M
authors: Viettri
authors: Instituto de Investigaciones Biomédicas "Dr. Francisco J. Triana Alonso" (BIOMED); Departamento de Parasitología, Facultad de Ciencias de la Salud, Universidad de Carabobo Sede Aragua, Maracay, Venezuela.
authors: Elizabeth
authors: E
authors: Ferrer
mesh_terms: D000818:Animals; D001483:Base Sequence; D014355:Chagas Disease / Q000469:parasitology*; D021901:DNA, Intergenic / Q000235:genetics; D016054:DNA, Protozoan / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005091:Exons / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D017422:Sequence Analysis, DNA; D014349:Trypanosoma cruzi / Q000235:genetics* / Q000302:isolation & purification; D014687:Venezuela
chemical_list: D021901:DNA, Intergenic; D016054:DNA, Protozoan; D004275:DNA, Ribosomal