Genetic polymorphism of metabolic enzymes of Leishmania spp. parasites isolated from different clinical types of cutaneous leishmaniasis patients
Genetic polymorphism of metabolic enzymes of Leishmania spp. parasites isolated from different clinical types of cutaneous leishmaniasis patients
Mahmoud Nateghi Rostami,1,*Mansoureh Hosseini,2Fatemeh Darzi,3
1. Department of Parasitology, Pasteur Institute of Iran 2. Department of Microbiology, Faculty of Advanced Sciences, Islamic Azad University of Medical Sciences 3. Department of Parasitology, Pasteur Institute of Iran
Introduction: Cutaneous leishmaniasis (CL), mainly caused by Leishmania major and L. tropica species, is a geographically extensive disease with diverse clinical manifestations. The most common CL lesion is a self-healing typical ulcer, leaving a scar, however, lesions can be highly polymorphic, and frequently appear as atypical lesions described as ‘eczematoid’, ‘chancriform’, ‘erysipeloid’, ‘zosteriform’, ‘lupoid’, ‘sprotrichoid’, etc. Parasite genetic diversity is proposed to be one of the factors affecting the characteristics of clinical lesions in CL. This study aim to explore potential association of genetic diversity of enzymatic markers with clinical type of CL.
Methods: Specific genes encoding metabolic enzymes, mainly used for MLEE, including isocitrate dehydrogenase (icd), mannose phosphate isomerase (mpi), glucose-6-phosphate dehydrogenase (g6pd), fumarate hydratase (fh), 6-phosphogluconate dehydrogenase (6pgd) and aspartate aminotransferase (asat) were selected. We applied a PCR-sequencing and multilocus sequence typing (MLST) analysis to explore genetic variations of Leishmania strains isolated from atypical vs. typical CL patients from Iran using BioEdit, Mega7, DnaSP and MLSTest softwares.
Results: A total of 41 isolates of L. major (28/41) and L. tropica (13/41) from 21 (51.2%) atypical CL and 20 (48.8%) typical CL cases were included. A set of additional sequences of 41 strains of 17 species of Leishmania were retrieved from databases. Different SNP variations were detected and the highest rate of heterozygous sites was found in g6pd and 6pgd genes (6 sites) for L. tropica and in asat and 6pgd genes (7 sites) for L. major strains. All strains were clustered into 58 unique sequence types (STs) including 17 STs related to 41 strains of Leishmania of this study. Concatenated tree clustered all strains in 6 main clades (A to F) including L. major (clade D) and L. tropica (clade B) strains. All of the STs were related in clonal complexes by using eBURST with the prediction of founder genotypes.
Conclusion: A high rate of genetic variations and heterozygocity was evident in L. tropica and L. major strains; nevertheless, there was no significant difference in the diversity of Leishmania strains between typical CL and atypical CL groups. This study represents the first successful application of MLST approach to L. tropica and L. major strains in Iran.