6th Pre – WorldLeish 7 webinar: «Species diversity or diversity of names? Patterns hidden behind Leishmania taxonomy»

PreWorldLeish 7 Elisa Cupolillo

Medellín, 23 of August, 2021

WorldLeish7 organizing committee invites you to next the Pre – WorldLeish 7 Webinar on Monday, September the 13th, at 9:00 a.m. Bogotá, 11:00 a.m. Brasilia and 4:00 p.m. Madrid.

This time, we will host the conference “Species diversity or diversity of names? Patterns hidden behind Leishmania taxonomy» presented by Dr. Elisa Cupolillo.

Dr. Elisa Cupolillo is a Senior Researcher at the Oswaldo Cruz Foundation (Fiocruz), head of the Research Laboratory on Leishmaniasis (LPL-IOC), responsible for the reference service in Leishmania identification to the Brazilian Ministry of Health and Pan-American Health Organization (PAHO), and Curator of the Leishmania collection from Oswaldo Cruz Institute. PI and partner of many research project, with an extensive collaborators network specialized in different aspects of leishmaniasis, contributing mainly on molecular systematics of Leishmania spp. to reveal epidemiological pattern of leishmaniasis.

About the presentation:

The genus Leishmania was first described in 1903, and so far, several species have been defined. Most of them were first described on the basis of ecological, epidemiological and biological characteristics. Currently, recent hierarchical taxonomic schemes have been progressively accessing intrinsic characters to assign Leishmania organisms into different species; yet they are still heirs of these earlier extrinsic-characters based classifications. The current classification system, which proposes just over 30 species, is mainly based on multilocus enzymatic electrophoresis. 

As for DNA sequencing based approaches, many genes have been targeted for Leishmania taxonomy, but almost all the species identification DNA sequence analysis have failed, which can be attributed to imperfect taxonomy (overlumping or overspliting) or incomplete lineage classification. In a broad sense, single-locus analysis has been referred to as barcoding, although “traditional” barcode studies employ the mitochondrial gene of Cytochrome oxidase I – COI. In all barcode studies (broad sense), the identification of Leishmania species considers MLEE results, and no study shows full agreement between DNA sequence analysis and MLEE. Disagreements were even detected between Single-locus DNA sequence analyses. This scenario indicates that a comprehensive taxonomic revision (species boundary delineation) is decisive in DNA based studies. Complete genome sequencing is a great ally for taxonomy, enabling the discovery of possible hidden cryptic species, providing a coherent means to systematize taxa into defined clades and also revealing possible biogeographic patterns. Putting this routine into taxonomic studies is still a dream. But we can think in reverse and use complete genomes to define the genomic regions useful for species identification, creating molecular dichotomous keys. To understand and anticipate emergence of Leishmania and leishmaniasis (most often old diseases in new hosts), one depends critically on the ability to identify the parasite. Taxonomy provides the names and it is easy to understand ‘no name= no information, wrong name = wrong information’. A fundamental contribution of molecular systematics has been to demonstrate that taxonomic ‘splitters’ have almost always been more correct than taxonomic ‘lumpers’. The systematics and taxonomy link evolution, ecology, biogeography in a rich and integrated tapestry describing global diversity. Systematic studies thus, are essential to the explanatory adequacy of the evolutionary and ecological framework that we use to interpret patterns and processes affecting emergence and re-emergence of disease and of many relevant characteristics, such as drug resistance. However, research efforts are currently isolated in a manner consistent with the analogy of ‘the blind men and the elephant’. We remain fragmented across disciplines within “Leishmania World”, failing to ‘connect the dots’ across diverse expertise and divergent interests and the consequences are in front of our eyes. Support for the expansion and maintenance of Leishmania collections is decreasing and Leishmania’ in vitro isolation has been placed in the background in many places, as a result of methodological difficulties, lack of financial resources and the possibility of identification by molecular methods without the need of parasite isolation. We need to think about the harm of a possible vacuum in terms of availability of Leishmania spp cultures that represent extremely relevant ecological and epidemiological scenarios occurring in the present. Even whole genome-based studies will be not very useful if studies focus on limited sampling. Furthermore, reflecting on the interface between accessing and sharing pathogens associated with a neglected disease and for the benefit of public health seems to be crucial.

The sixth webinar is part of the cycle of conferences held every two months in preparation for the seventh version of WorldLeish, a global congress on leishmaniasis convened every four years in a different country. The 7th WorldLeish congress will take place from the1st to the 6th of August 2022, in Cartagena, Colombia.

Join the webinar here:

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