Identification of Trypanosoma cruzi zymodemes by kinetoplast DNA probes

Analysis of zymograms of extracts of Trypanosoma cruzi isolated from differ ent hosts in Argentina allowed characterization of 12 zymodemes or "isozymi c strains," only six of which were found in human patients. Two of these si x zymodemes (Z1 and Z12) were widely distributed and found in more than 80% of human patients. These two "major natural clones" differed significantly in pathogenic activity. Because the groupings obtained by studying enzymes and kinetoplast DNA (kDNA) were similar, it is possible to identify the zy modeme by analyzing kDNA. A 290-bp fragment was amplified by PCR using prim ers for the sequences flanking the hypervariable regions of kDNA minicircle s. Labeled probes for this fragment, prepared from Z1 and Z12 reference sto cks, hybridized specifically with PCR-amplified kDNA from parasite stocks, allowing identification of zymodemes.