kDNA gene signatures of Trypanosoma cruzi in blood and oesophageal mucosa from chronic chagasic patients.

Trypanosoma cruzi presents a high degree of intraspecific variability, with possible implications for the pathogenesis of Chagas disease. The aim of this study was to evaluate T. cruzi kDNA minicircle gene signatures using the low-stringency single-specific-primer PCR technique in both peripheral blood and oesophageal mucosa from chronic chagasic patients, with or without megaesophagus, alone or in combination with cardiopathy and megacolon. It was not possible to identify a uniform pattern of shared bands between blood and oesophageal mucosa samples from individuals with the same clinical form or mixed forms, suggesting multiple T. cruzi infections with differential tissue tropism. Thus, the results indicate that there is an intense intraspecific variability in the hypervariable regions of T. cruzi kDNA, which has so far made it impossible to correlate the genetic profile of this structure with the clinical manifestations of Chagas disease.