Tegumentary leishmaniasis by Leishmania braziliensis complex in Bolivia:
the presence of L. braziliensis outlier
Leishmaniasis is caused by protozoans of the Leishmania genus,
which includes more than 20 species capable of infecting humans
worldwide. In the Americas, the most widespread specie is L.
braziliensis, present in 18 countries, including Bolivia. The taxonomic
position of the L. braziliensis complex has been a subject of
controversy, complicated further by the recent identification of a
particular subpopulation named L. braziliensis atypical or
outlier. The aim of this study was to carry out a systematic analysis of
the L. braziliensis complex in Bolivia and to describe the
associated clinical characteristics. Forty-one strains were analyzed by
sequencing an amplified 1245 bp fragment of the hsp70 gene, which
allowed its identification as: 24 (59%) L. braziliensis, 16
(39%) L. braziliensis outlier and one (2%) L. peruviana.
In a dendrogram constructed, L. braziliensis and L.
peruviana are grouped in the same cluster, whilst L.
braziliensis outlier appears in a separate branch. Sequence alignment
allowed the identification of five non-polymorphic nucleotide positions
(288, 297, 642, 993 and 1213) that discriminate L. braziliensis
and L. peruviana from L. braziliensis outlier. Moreover,
nucleotide positions 51 and 561 enable L. peruviana to be
discriminated from the other two taxa. A greater diversity, was observed
in L . braziliensis outlier than in L. braziliensis-
L. peruviana. The 41 strains came from 32 patients with
tegumentary leishmaniasis, among which 22 patients (69%) presented
cutaneous lesions (11 caused by L. braziliensis and 11 by
L. braziliensis outlier) and ten patients (31%) mucocutaneous
lesions (eight caused by L. braziliensis, one by L.
braziliensis outlier and one by L. peruviana). Nine patients
(28%) simultaneously provided two isolates, each from a separate
lesion, and in each case the same genotype was identified in both.
Treatment failure was observed in six patients infected with L.
braziliensis and one patient with L. peruviana.