RANDOMLY AMPLIFIED POLYMORPHIC DNA (RAPD) AND ISOENZYME ANALYSIS OF TRYPANOSOMA-RANGELI STRAINS

Sixteen Trypanosoma rangeli strains were compared by isoenzyme and ran domly amplified polymorphic DNA (RAPD) analysis. Eight strains were is olated from either Rhodnius prolixus or Home sapiens from Honduras, Co lombia and Venezuela. Another eight strains were isolated from either Panstrongylus megistus or the rodent Echimys dasythrix from the State of Santa Catarina, southern Brazil. All six T. rangeli strains isolate d from P. megistus were co-infections with Trypanosoma cruzi, demonstr ating an overlap of the sylvatic cycles of these parasites and that th e accurate identification of species is of utmost importance. Both iso enzyme and RAPD analysis revealed two distinct groups of T. rangeli st rains, one formed by the strains from Santa Catarina and the other, by the strains from Honduras, Colombia and Venezuela. With the five enzy mes used, all the strains from Santa Catarina had identical profiles w hich overlapped with those of the other regions only in the pattern ob tained with malic enzyme. Analysis of 138 RAPD bands by means of an un weighted pair group method analysis (UPGMA) phenogram using the Dice s imilarity coefficient allowed the separation of the two groups based o n their divergence at a lower level of similarity than the phenon line . We show that the identification of T. cruzi and T. rangeli in natura lly mixed infections is readily achieved by either RAPD or isoenzyme a nalysis.