Abstract

Background: Leishmania (L.) killicki is responsible for the chronic cutaneous leishmaniasis. The
taxonomic status of this parasite is still not well defined. It was suggested on one hand to include
this taxon within L. tropica complex but also on the other hand to consider it as a distinct
phylogenetic complex. The present work represents the more detailed study on the evolutionary
history of L. killicki relative to L. tropica and the taxonomic implications.
Methods: Thirty five L. killicki and 25 L. tropica strains isolated from humans and from several
countries were characterized using the MultiLocus Enzyme Electrophoresis (MLEE) and the
MultiLocus Sequence Typing (MLST) approaches.
Results: The genetic and phylogenetic analyses strongly support that L. killicki belongs to L.
tropica complex. The study suggests the emergence of L. killicki by a funder effect followed by an
independent evolution from L. tropica, but does not validate the species status of this taxon. In this
context, we suggest to call this taxon L. killicki (synonymous L. tropica) until further
epidemiological and phylogenetic studies justify the L. killicki denomination.
Conclusions: These findings provided taxonomic and phylogenetic informations on L. killicki and
helped to better know the evolutionary history of this taxon.