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DNA hybridisation was used to type 26 samples from lesions of human patients from the Rio Doce Valley (Minas Gerais, Brazil) clinically diagnosed as having cutaneous leishmaniasis, using kinetoplast DNA (kDNA) cloned mini-circle probes specific for the Leishmania mexicana and Leishmania braziliensis complexes. All samples were found to belong to the L. braziliensis complex. When biopsies were pressed directly onto touch blot membranes 38.5% of the samples were positive. The positivity and specificity obtained were both 100% when cultured blotted parasites were used. The results were confirmed by polymerase chain reaction (PCR) analysis using primers specific for the L. mexicana and L. braziliensis complexes.

Leishmania (Viannia) braziliensis isolates from two different geographic areas in Brazil were studied by DNA fingerprinting with the 33.15 multilocal probe and PCR with arbitrary primers (random amplification of polymorphic DNA-RAPD). The genetic distance of strains was measured by band sharing. The results showed that the strains isolated in Minas Gerais, southeastern Brazil, are very different from those isolated in Pará, northern Brazil. Strains from Minas Gerais constituted a relatively homogeneous group, presenting DNA fingerprint patterns with 76% of shared bands and RAPD profiles with 93% of shared bands. In contrast, strains from Pará showed higher genetic variability, with only 17 and 45% of shared bands in DNA fingerprint and RAPD patterns, respectively. This study suggests that genetic differences between L. braziliensis from both areas might have an epidemiological significance.