American tegumentary leishmaniasis: antigen-gene polymorphism, taxonomy and clinical pleomorphism

Abstract Multi-locus enzyme electrophoresis is the current gold standard for the genetic characterisation of Leishmania. However, this method is time-consuming and, more importantly, cannot be directly applied to parasites present in host tissue. PCR-based methods represent an ideal alternative but, to date, a multi-locus analysis has not been applied to the same sample. This has now been achieved with a sample of 55 neotropical isolates ( Leishmania ( Viannia ) braziliensis , L. ( V. ) peruviana , L. ( V. ) guyanensis , L. ( V. ) lainsoni and L. ( L. ) amazonensis ), using five different genes as targets, four of which encoded major Leishmania antigens ( gp63 , Hsp70 , H2B and Cpb ). Our multi-locus approach strongly supports the current taxonomy and demonstrates a highly robust method of distinguishing different strains. Within L. ( V. ) braziliensis , we did not encounter so far specific genetic differences between parasites isolated from cutaneous and mucosal lesions. Interestingly, results provided by each of the different antigen-genes in the species considered, were different, suggesting different selective pressures. Our work emphasises the need for a multi-disciplinary approach to study the clinical pleomorphism of leishmaniasis.