The Genetic Relationship between Leishmania aethiopica and Leishmania tropica Revealed by Comparing Microsatellite Profiles

Abstract

Background Leishmania (Leishmania) aethiopica and L. (L.) tropica cause cutaneous leishmaniases and appear to be related. L. aethiopica is geographically restricted to Ethiopia and Kenya; L. tropica is widely dispersed from the Eastern Mediterranean, through the Middle East into eastern India and in north, east and south Africa. Their phylogenetic inter-relationship is only partially revealed. Some studies indicate a close relationship. Here, eight strains of L. aethiopica were characterized genetically and compared with 156 strains of L. tropica from most of the latter species' geographical range to discern the closeness.Methodology/Principal FindingsTwelve unlinked microsatellite markers previously used to genotype strains of L. tropica were successfully applied to the eight strains of L. aethiopica and their microsatellite profiles were compared to those of 156 strains of L. tropica from various geographical locations that were isolated from human cases of cutaneous and visceral leishmaniasis, hyraxes and sand fly vectors. All the microsatellite profiles were subjected to various analytical algorithms: Bayesian statistics, distance-based and factorial correspondence analysis, revealing: (i) the species L. aethiopica, though geographically restricted, is genetically very heterogeneous; (ii) the strains of L. aethiopica formed a distinct genetic cluster; and (iii) strains of L. aethiopica are closely related to strains of L. tropica and more so to the African ones, although, by factorial correspondence analysis, clearly separate from them.Conclusions/SignificanceThe successful application of the 12 microsatellite markers, originally considered species-specific for the species L. tropica, to strains of L. aethiopica confirmed the close relationship between these two species. The Bayesian and distance-based methods clustered the strains of L. aethiopica among African strains of L. tropica, while the factorial correspondence analysis indicated a clear separation between the two species. There was no correlation between microsatellite profiles of the eight strains of L. aethiopica and the type of leishmaniasis, localized (LCL) versus diffuse cutaneous leishmaniasis (DCL), displayed by the human cases.

Population Structure of Leishmania using POPSICLE reveals extensive dichotomy in zygosity and discloses the role of sex in diversity of the parasite

“…The phylogenetic analysis using hierarchical clustering framework with complete linkage revealed that strains belonging to the same species and species belonging to a sub-genus generally grouped together, although some exceptions were seen ( Figure 2B). The species L. tropica and L. aethiopica formed a subgroup that suggested close association between them, a finding consistent with what previously been reported in a comparative analysis performed using microsatellite markers (Krayter et al 2015). Similarly, the L. donovani complex containing L. infantum and L. donovani were assigned to a single clade, signifying their genomic similarity as reported previously (Lukes et al 2007).…”

Expanded genome-wide comparisons give novel insights into population structure and genetic heterogeneity of Leishmania tropica complex

“…Multilocus microsatellite typing (MLMT) was performed in silico by blasting the forward and reverse primer sequences on each genome using the BioNumerics software version 7.6.1 (Applied Maths, Sint-Martens-Latem, Belgium). In total, 12 independent microsatellite genetic markers specific to L. tropica (GA1, GA2, GA6, GA9n, LIST7010, LIST7011, LIST7027, LIST7033, LIST7039, LIST7040, 4GTG and 27GTGn) were used as previously described by Krayter and colleagues [13,14,15] and for eight L. aethiopica isolates [29]. Bayesian, distancebased and factorial correspondence analyses revealed two populations: India/Asia and Israel/ Palestine that were subdivided, respectively, into two and three subpopulations [14].…”

“…In this study, we perform a comparative genome analysis of three novel L. tropica genomes: two recent (2014) clinical isolates representing the outbreak of CL in Lebanon and one historical isolate from Azerbaijan (1974), with previously generated genome sequence data from 16 isolates [18,19]. Notably, we integrated the 19 WGS data with a wide microsatellite based genotyping survey across over 160 L. tropica strains [14,15,29] contributing to rationalise comparative analyses of SNPs and CNVs as well as chromosome ploidy. This study provides new insights into the population structure and genomic diversity of L. tropica parasites and integrate these into a more global comparative framework.…”

“…This study provides new insights into the population structure and genomic diversity of L. tropica parasites and integrate these into a more global comparative framework. Notably, sampling of new strains from the Middle East is also of particular interest for comparative studies as this is one of the regions with the highest prevalence for L. tropica infections, which are characterised by a complex and broad genetic diversity apparently derived from distinct lineages [14,15,29]. Furthermore, CL appears to be re-emerging in various countries in the Middle East and Transcaucasia [27,30].…”

Spatiotemporal and molecular epidemiology of cutaneous leishmaniasis in Libya

“…killicki ) is more prevalent in Morocco causing 30–40% of the CL cases in some districts [ 10 ]. Leishmania aethiopica is found exclusively in Africa and is considered as the main causative agent of CL in Ethiopia and Kenya [ 7 , 11 ]. Less frequently, CL can be also due to L .…”