Association between an emerging disseminated form of leishmaniasis and Leishmania (Viannia) braziliensis strain polymorphisms

Abstract

Leishmania (Viannia) braziliensis causes three main types of American tegumentary leishmaniasis (ATL), localized cutaneous leishmaniasis (CL), mucosal leishmaniasis (ML), and disseminated leishmaniasis (DL). All forms are observed among individuals of Corte de Pedra, Brazil. We previously used random amplified markers to identify a multiclonal population among L. (V.) braziliensis isolates from ATL patients, defining parasite clades associated with different clinical syndromes. Herein we compared sequences of random amplified markers to identify genotypes of L. (V.) braziliensis recovered from lesions of CL, ML, and DL patients. Six polymorphic genomic loci were sequenced from 35 parasite isolates. Single-nucleotide polymorphisms (SNPs) and insertions-deletions (indels) at each locus allowed us to segregate the L. (V.) braziliensis population according to haplotypes. Several SNPs, indels, and haplotypes were significantly associated with an increased risk of DL. Molecular genotyping may provide markers to identify L. (V.) braziliensis strains likely to cause this emerging, hard-to-treat form of ATL.

Fig 1

Electrophoretic patterns of L. (V.) braziliensis genomic DNA amplicons generated using three RAPD protocols (separately depicted in panels A, B, and C) previously described (27). Marked bands were excised, cloned, sequenced, and then aligned among nine L. (V.) braziliensis isolates from Corte de Pedra to detect polymorphisms. The polymorphic loci detected among parasites from Corte de Pedra were CHR 24/3074 (chromosome 24, starting at position 3074) (B1), CHR 26/765 (B2), CHR 28/195696 (B3), CHR 28/425451 (B4), CHR 32/1356278 (B5), and CHR 35/335652 (B6). The CHR 26/765 locus was found duplicated on chromosome 33 starting at position 1476284. Lanes: L1, molecular size markers; L2 and L3, examples of L. (V.) braziliensis isolates. Estimated nucleic acid lengths in base pairs are shown.