title: Trypanosoma cruzi: Evaluation of PCR as a Laboratory Tool to Follow up the Evolution of Parasite Load.
abstract: BACKGROUND
  The study evaluated qualitative PCR, primers 121-122 as a tool to follow up evolution parasite load ofTrypanosoma cruzi.
  
  
  METHODS
  The study was conducted at the State University of Maringa, in 2015. Step 1, dilutions 1/10 were performed fromT. cruzi-Y strain to obtain preparations of 50,000-0.05 parasites/mL from which DNA were extracted, quantified, and amplified. Step 2, the extracted DNA in the dilutions 5-0.05 parasites/mL was re-diluted 1/10, 1/100, 1/1000, quantified, and amplified. Polyacrylamide gels were photographed and thicknesses of the 330 bp kDNA fragments were measured.
  
  
  RESULTS
  Step 1, in the dilutions 50,000-50 parasites/mL kDNA fragments had same thickness and, dilutions 5-0.05 parasites/mL showed progressive decrease in thicknesses and staining intensity of the 330 bp fragments. Step 2, demonstrated that dilutions of five (re-dilutions 1/10 and 1/100) and 0.5 (1/10) parasites/mL produced similar thicknesses of the 330 bp fragments obtained in Step 1. However, very dilute DNA samples make difficult to reproduce the fragments thicknesses.
  
  
  CONCLUSIONS
  PCR, despite its limitations, was able to detect progressive decrease in thicknesses/staining intensity of kDNA fragments in the dilutions 5-0.05 parasites/mL. Hence, has the potential to be used to follow-up evolution of parasite load, not by quantifying the number of parasites, but by dynamic evolution of the fragments thicknesses during etiological treatment.
authors.affiliation: Dept. of Basic Health Sciences, Sector of Parasitology, State University of Maringa, Maringa, Brazil.
authors.forename: Fabiana Nabarro
authors.initials: FN
authors.lastname: Ferraz
authors.affiliation: Dept. of Basic Health Sciences, Sector of Parasitology, State University of Maringa, Maringa, Brazil.
authors.forename: Denise Lessa
authors.initials: DL
authors.lastname: Aleixo
authors.affiliation: Dept. of Basic Health Sciences, Sector of Parasitology, State University of Maringa, Maringa, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Gruendling
authors.affiliation: Dept. of Basic Health Sciences, Sector of Parasitology, State University of Maringa, Maringa, Brazil.
authors.forename: Mônica Lúcia
authors.initials: ML
authors.lastname: Gomes
authors.affiliation: Dept. of Basic Health Sciences, Sector of Parasitology, State University of Maringa, Maringa, Brazil.
authors.forename: Max Jean de Ornelas
authors.initials: MJ
authors.lastname: Toledo
authors.affiliation: Dept. of Basic Health Sciences, Sector of Parasitology, State University of Maringa, Maringa, Brazil.
authors.forename: Silvana Marques
authors.initials: SM
authors.lastname: DE Araújo
keywords: PCR; Parasite load; Trypanosoma cruzi; kDNA fragments