Caracterización molecular de los genes histona H2A y ARNsno-Cl de Trypanosoma rangeli:: aplicación en pruebas diagnósticas

Abstract

The application of polymerase chain reaction (PCR) to detect Trypanosoma cruzi and Trypanosoma rangeli often presents interpretation challenges. For example, some tests yield the amplification of similar bands from either parasite, polymorphic fragments of the same parasite, or present deviation towards T. cruzi in mixed infections.In this study, the basic researching needed for designing and standardizating specific PCR tests for each parasite species PCR are shown and analyzed. The TcH2AF/R primers were designed on the basis of the differential gene region observed between the histone h2a genic units of these parasites. These primers amplify a specific 234 bp fragment in T. cruzi (T. cruzi I and II strains). The TrF/R2 primers anneal to the intergenic regions of an 801 bp gene fragment encoding for six transcripts that conform the snoRNA-Cl cluster in T. rangeli. These primers amplify a fragment of 620 bp exclusively in KP1(-) and KP1(+) strains of the parasite.The application of these PCR tests in infected vectors and in chagasic patients show that both tests constitute useful tools for the diagnosis and differential identification of these trypanosomatids.