Deciphering Host-Parasite Interplay in Leishmania Infection through a One Health View of Proteomics Studies on Drug Resistance.

Recent efforts in the study of vector-borne parasitic diseases (VBPDs) have emphasized an increased consideration for preventing drug resistance and promoting the environmental safety of drugs, from the beginning of the drug discovery pipeline. The intensive use of the few available antileishmanial drugs has led to the spreading of hyper-resistant Leishmania infantum strains, resulting in a chronic burden of the disease. In the present work, we have investigated the biochemical mechanisms of resistance to antimonials, paromomycin, and miltefosine in three drug-resistant parasitic strains from human clinical isolates, using a whole-cell mass spectrometry proteomics approach. We identified 14 differentially expressed proteins that were validated with their transcripts. Next, we employed functional association networks to identify parasite-specific proteins as potential targets for novel drug discovery studies. We used SeqAPASS analysis to predict susceptibility based on the evolutionary conservation of protein drug targets across species. MATH-domain-containing protein, adenosine triphosphate (ATP)-binding cassette B2, histone H4, calpain-like cysteine peptidase, and trypanothione reductase emerged as top candidates. Overall, this work identifies new biological targets for designing drugs to prevent the development of Leishmania drug resistance, while aligning with One Health principles that emphasize the interconnected health of people, animals, and ecosystems.

Tri-aryl antimony(V) hydroximato and hydroxamato complexes: Combining lipophilic Sb(III/V) and hydroxamic acids in combating Leishmania.

Six novel tri-aryl antimony(V) hydroximato complexes (3-8) with composition [SbAr3(O2NCR)] (3: Ar = Ph, R = o-(OH)Ph, 4: Ar = Ph, R = Me, 5: Ar = Ph, R = Ph; 6: Ar = Mes, R = Me, 7: Ar = Mes, R = Ph, 8: Ar = Mes, R = o-(OH)Ph (where Ph = phenyl, Me = methyl, Mes = mesityl)), were synthesised and evaluated for anti-parasitic activity towards Leishmania major (L. major) promastigotes and amastigotes. Complexes of the form [SbAr3(O2NCR)], with the dianionic hydroximato ligand binding O,O'-bidentate to the Sb(V) centre, exist in the solid-state for the mesityl-derived complexes. In contrast, the phenyl-ligated Sb(V) complexes crystallise as the hexacoordinate, hydroxamato species [SbPh3(O2NHC(OH))], with the OH ligand derived from entrained H2O in the crystallisation solvent. It is found that both the aryl and hydroximato ligands are found to influence the bioactivity of the Sb(V) complexes. Complexes 3-8 exhibited varied anti-promastigote activity with IC50 values ranging from 1.53 µM for 6 to 36.0 µM for 3, also reflected in varied anti-amastigote activity with a percentage infection range of 5.50% for 6 to 29.00% for 3 at a concentration of 10 µM. The complexes were relatively non-toxic to human fibroblasts with an IC50 value range of 59.3 µM (7) to ≥100 µM (3-6, 8), and exhibited varied toxicity towards J774.1 A macrophages (IC50: 3.97 (6) to ≥100 (8) µM). All complexes showed enhanced activity compared to the parent hydroxamic acids.

Antileishmanial natural products as potential inhibitors of the Leishmania pteridine reductase: insights from molecular docking and molecular dynamics simulations.

Although many natural product-derived compounds possess anti-leishmanial activities in vitro and in vivo, their molecular targets in the Leishmania parasite remain elusive. This is a major challenge in optimizing these compounds into leads. The Leishmania pteridine reductase (PTR1) is peculiar for folate and pterin metabolism and has been validated as a drug target. In this study, 17 compounds with anti-leishmanial activities were screened against Leishmania major PTR1 (LmPTR1) using molecular docking and molecular dynamics (MD) simulations. All ligands were bound in the active site pocket of LmPTR1 with binding affinities ranging from -11.2 to -5.2 kcal/mol. Agnuside, betulin, betulinic acid, gerberinol, ismailin, oleanolic acid, pristimerin, and ursolic acid demonstrated binding affinities similar to a known inhibitor, methyl 1-(4-{[2,4-diaminopteridin-6-yl) methyl] amino} benzoyl) piperidine-4-carboxylate (DVP). MD simulations revealed that betulin, betulinic acid, ismailin, oleanolic acid, pristimerin, and ursolic acid formed stable complexes with LmPTR1. The binding free energies of the complexes were very good (-87 to -148 kJ/mol), and much higher than the complex of the standard DVP inhibitor and LmPTR1 (-27 kJ/mol). Betulin, betulinic acid, ismailin, oleanolic acid, pristimerin, and ursolic acid likely exert their antileishmanial action by inhibiting PTR1 and could thus be used as a basis for the development of potential antileishmanial chemotherapeutic agents. Supplementary Information: The online version contains supplementary material available at 10.1007/s40203-024-00247-8.

Serosurvey of canine leishmaniasis in five departments near an identified human clinical case in Marseille (France).

Leishmania infantum is a protozoan parasite of the family Trypanosomatidae, transmitted by the bite of phlebotomine sand flies (Diptera: Psychodidae). It is responsible for human and canine leishmaniasis in countries bordering the Mediterranean basin. Here we describe a clinical case of human cutaneous leishmaniasis in a 76-year-old female patient living in Marseille. Upon interrogation, the patient had no history of recent travel or contact with animals. The study involved clinical, serological, and molecular investigation of the occurrence of Leishmania infection in 718 dogs from five departments within a 130 km radius perimeter around Marseille. Five dogs showed signs of moderate leishmaniasis. Additionally, the serological survey of dogs revealed a global seroprevalence of 5.1%, with a significantly different prevalence in the Vaucluse department. Molecular analysis and phylogenetic studies highlighted the close relatedness of Leishmania strains between human and canine hosts with 99.6% of identity, indicating local transmission. The findings underscore the importance of serological surveillance in dogs and human. In a One Health approach, it is necessary to continue investigating Leishmania infection in all potential reservoirs, especially for zoonotic L. infantum in wildlife (red foxes, leporids, rodents, etc.) but also in dogs, cats, and equids.

Canine leishmaniosis global prevalence over the last three decades: a meta-analysis and systematic review.

Leishmaniosis by Leishmania infantum is a zoonotic vector-borne disease transmitted to humans and dogs by the bite of female sand-flies. The domestic dog is the main reservoir and infected dogs may show or not clinical symptoms. The prevalence of infection in dogs varies according to the population studied, the geographic area, and the diagnostics employed. This study aims to estimate the global prevalence, subgrouping per continent, country, diagnostic test and selected risk factors. Cross-sectional studies (n=150; from 1990 to 2020) estimating the prevalence of the infection by Leishmania infantum were extracted from four electronic databases. The pooled global prevalence obtained by random-effects meta-analysis was 15.2 % (95 %CI 13.6-16.9), mostly in rural (19.5 %) and owned dogs (16.5 %). Prevalence varied if the diagnosis was made by western blot (WB, 32.9 %), cellular immunity tests (27.5 %), ELISA (17 %), PCR (16.9 %), IFAT (15.9 %), rapid tests and direct agglutination test (DAT, 11.5 %), cytology/immunohistochemistry (13.1 %), culture (8.6 %). A small studies bias (P<0.005) in the overall prevalence meta-analysis, due to the impact of small-size studies on the overall results was found. Moreover, a continent-related bias was found regarding rapid test, DAT (P=0.021), and WB (P<0.001), as these assays are mainly used in South American studies. A study period bias (P=0.033) and a publication year bias (P=0.002) were detected for PCR, as the test was not employed before the year 2000. In conclusion, a high prevalence of canine leishmaniosis worldwide and high heterogeneity among studies were found.

In silico and experimental potentials of 6-shogaol and meglumine antimoniate on Leishmania major: multiple synergistic combinations through modulation of biological properties.

Conventional therapeutic agents are no longer adequate against leishmaniasis. This complex condition continues to have a high mortality rate and public health impact. The present study aimed to explore an extensive array of experiments to monitor the biological activities of 6-shogaol, a major component of ginger, and meglumine antimoniate (MA or Glucantime®). The binding affinity of 6-shogaol and inducible nitric oxide synthase (iNOS), a major enzyme catalyzing nitric oxide (NO) from L-arginine was the source for the docking outline. The inhibitory effects of 6-shogaol, MA, and mixture were assessed using colorimetric and macrophage assays. Antioxidant activity was inferred by UV-visible spectrophotometry. Variably expressed genes were measured by quantifiable real-time polymerase chain reaction. Apoptotic and cell cycle profiles were analyzed by flow cytometry. Moreover, a DNA fragmentation assay was performed by electrophoresis and antioxidant metabolites include superoxide dismutase (SOD), catalase (CAT), and also nitric oxide (NO) by enzyme-linked immunosorbent assay. 6-shogaol and MA exhibited multiple synergistic mechanisms of action. These included a remarkable leishmanicidal effect, potent antioxidative activity, a high safety index, upregulation of M1 macrophages/Th1-associated cytokines (including, γ-interferon, interleukin-12p40, tumor necrotizing factor-alpha, and associated iNOS), significant cell division capture at the sub-G0/G1 phase, a high profile of apoptosis through DNA fragmentation of the nuclear components. In addition, the activity of NO was substantially elevated by treated intracellular amastigotes, while SOD and CAT activities were significantly diminished. This study is exclusive because no similar investigation has inclusively been conducted before. These comprehensive mechanistic actions form a logical foundation for additional advanced study.

Development of Amphotericin B Decorated Gold Nanoparticles as a Promising Antileishmanial Nanoconjugate.

Leishmaniasis, attributed to the protozoan parasite Leishmania, manifests in diverse clinical forms, including cutaneous, mucocutaneous, and visceral leishmaniasis; VL constitutes a significant global health menace. Prevalent in tropical and subtropical regions, this affliction disproportionately impacts individuals below the poverty threshold, transmitted through the bite of female sandflies. Existing treatments, such as pentavalent antimony, miltefosine, and Amphotericin B, exhibit limitations. Despite the emergence of liposomal Amphotericin B (AmBisome) as a promising antileishmanial agent, its utility is impeded by adverse effects, elevated production expenses, and cytotoxicity. To address these challenges, our investigation introduces a potential remedy─a citrate-coated gold Amphotericin B nanoparticle formulation. Characterized using dynamic light scattering and transmission electron microscopy, this pioneering formulation exhibited efficacy against L. donovani Ag83 promastigotes as demonstrated by MTT cell viability testing. Evaluating internal reactive oxygen species (ROS) levels and dual staining with acridine orange and ethidium bromide unveiled its consequential impact on cell death. Significantly, our study discloses this novel nanoformulation's unprecedented inhibition of the trypanothione reductase enzyme. The findings posit the citrate-coated gold Amphotericin B nanoformulation as a promising and targeted antileishmanial agent, representing potential advancements in leishmaniasis therapeutics.

Transcriptome and proteome changes triggered by overexpression of the transcriptional regulator Maf1 in the human pathogen Leishmania major.

Maf1, originally described as a repressor of RNA polymerase III (RNAP III) transcription in yeast, participates in multiple functions across eukaryotes. However, the knowledge about Maf1 in protozoan parasites is scarce. To initiate the study of Maf1 in Leishmania major, we generated a cell line that overexpresses this protein. Overexpression of Maf1 led to a significant reduction in the abundance of tRNAs, 5S rRNA, and U4 snRNA, demonstrating that Maf1 regulates RNAP III activity in L. major. To further explore the roles played by Maf1 in this microorganism, global transcriptomic and proteomic changes due to Maf1 overexpression were determined using RNA-sequencing and label-free quantitative mass spectrometry. Compared to wild-type cells, differential expression was observed for 1082 transcripts (615 down-regulated and 467 up-regulated) and 205 proteins (132 down-regulated and 73 up-regulated) in the overexpressing cells. A correlation of 44% was found between transcriptomic and proteomic results. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses revealed that the differentially expressed genes and proteins are mainly involved in transcription, cell cycle regulation, lipid metabolism and transport, ribosomal biogenesis, carbohydrate metabolism, autophagy, and cytoskeleton modification. Thus, our results suggest the involvement of Maf1 in the regulation of all these processes in L. major, as reported in other species, indicating that the functions performed by Maf1 were established early in eukaryotic evolution. Notably, our data also suggest the participation of L. major Maf1 in mRNA post-transcriptional control, a role that, to the best of our knowledge, has not been described in other organisms.

Semen Cannabis and Oleum Hyperici: Antileishmanial activity against Leishmania tropica promastigotes and intracellular amastigotes.

The exploration of alternative agents and novel drug candidates for the effective treatment of cutaneous leishmaniasis has garnered significant attention, driven by the high cost, toxic effects, and the emergence of drug resistance associated with current therapeutic options. Plant extracts derived from Semen Cannabis, the seeds of the Cannabis sativa L. (hemp) plant, and Oleum Hyperici, the oily macerate of Hypericum perforatum L. (St. John's Wort) plant, were prepared by using solvents of varying polarity (n-hexane, chloroform, ethanol, and 60% aqueous ethanol). The primary objective of this study was to research in vitro and ex vivo antileishmanial efficacy of Semen Cannabis and Oleum Hyperici plant extracts against Leishmania tropica promastigotes and intracellular amastigotes. The efficacy of plant extracts against promastigotes were assessed using the cell counting by hemocytometer and the CellTiter-Glo assay. Additionally, their impact on infected THP-1 macrophages and the quantity of intracelluler amastigotes were investigated. Cytotoxicity was evaluated in THP-1 macrophages. Among the tested plant extracts, chloroform extract of Oleum Hyperici demonstrated significant antileishmanial activity against promastigotes (SI: 12.6) and intracellular amastigotes (SI: 16.8) of L. tropica without inducing cytotoxic effects and hold promise for further investigation as potential antileishmanial agents.

Unraveling molecular mechanistic disparities in pathogenic visceral Leishmania resistance between reptiles and mammals through comparative transcriptomic analyses.

Leishmaniasis is one of the most important neglected tropical parasitic diseases, manifesting various clinical forms depending on the parasite species and the genetic background of the host. In order to elucidate the underlying mechanisms of reptilian defense against pathogenic Leishmania species and to delineate the global gene expression profile alterations during host-pathogen interaction, we established experimental animal and cell models using both heterothermic lizards (Phrynocephalus przewalskii) and homothermic mammals (BALB/c mice) infected with pathogenic Leishmania infantum (high virulence HCZ strain) and Leishmania donovani (low virulence 801 strain). Overall, the lizards didn't show any obvious clinical symptoms or immune responses in vivo. Using RNA-seq methodology, differentially expressed genes identified in the HCZ and 801-comparison groups of P. przewalskii were primarily associated with arginine biosynthesis, the MAPK signaling pathway and the PI3K-Akt signaling pathway. In contrast, higher parasite loads, exacerbated hepatic inflammatory lesions and enhanced immune responses were observed in BALB/c mice, with DEGs predominantly associated with immunological diseases, innate and adaptive immune responses. By integrating transcriptional data from reptile and mammalian hosts, we elucidated the pivotal role of amino acid metabolism and lipid metabolism in parasite control. In contrast to findings from animal experiments, Leishmania parasites effectively infected peritoneal macrophages of lizards in vitro, demonstrating a high infection rate. Furthermore, we used RT-qPCR to detect changes in cytokine expression in macrophages and found that Th1-type cytokines were significantly upregulated in lizards, facilitating the clearance of the HCZ strain 24 hours post-infection. Conversely, cytokine expression was generally suppressed in BALB/c mice, allowing immune evasion by the parasites.

Parasitic and Fungal Triggers of Cytokine Storm Syndrome.

Infections caused by parasites and fungi can trigger the cytokine storm syndrome (CSS). These infections causing CSS can occur together with acquired immunodeficiencies, lymphomas, the use of immunosuppressive medications, transplant recipients, cancer, autoinflammatory, and autoimmune diseases or less frequently in healthy individuals. Histoplasma, Leishmania, Plasmodium, and Toxoplasma are the most frequent organisms associated with a CSS. It is very important to determine a previous travel history when evaluating a patient with a CSS triggered by these organisms as this may be the clue to the causal agent. Even though CSS is treated with specific therapies, an effort to find the causal organism should be carried out since the treatment of the infectious organism may stop the CSS. Diagnosing a CSS in the presence of parasitic or fungal sepsis should also lead to the study of an altered cytotoxic or hemophagocytic response in the susceptible host.

Identification, characterization, and cellular localization of Leishmania major CTP:phosphocholine cytidylyltransferase.

The eukaryotic parasite Leishmania is the causative agent of the disease leishmaniasis, the second largest parasitic killer in the world behind malaria. A large percentage of Leishmania membrane phospholipids is phosphatidylcholine (PC), formed via the Kennedy pathway, where the enzyme CTP: phosphocholine cytidylyltransferase (CCT) catalyzes the second, rate limiting step. Leishmania major CCT was expressed in non-pathogenic Leishmania tarentolae and exhibited activity that increased 10-fold in the presence of PC:oleate lipid vesicles. Confocal microscopy of L. tarentolae expressing L. major CCT fused to a red fluorescent protein revealed the enzyme is cytoplasmic but may associate with internal membranes. A truncated mutant of L. major CCT containing the catalytic domain was expressed in Escherichia coli and in vitro analysis of the enzyme showed catalysis was divalent cation-dependent and yielded a Vmax of 374 nmol/min/mg and Km values of 0.0648 mM and 3.74 mM, respectively, for the substrates CTP and phosphocholine.

Identifying Rab2 Protein as a Key Interactor of Centrin1 Essential for Leishmania donovani Growth.

Previously, we have demonstrated that deletion of a growth-regulating gene (LdCen1) in the Leishmania donovani parasite (LdCen1-/-) attenuated the parasite's intracellular amastigote growth but not the growth of extracellular promastigotes. LdCen1-/- parasites were found to be safe and efficacious against homologous and heterologous Leishmania species as a vaccine candidate in animal models. The reason for the differential growth of LdCen1-/- between the two stages of the parasite needed investigation. Here, we report that LdCen1 interacts with a novel Ras-associated binding protein in L. donovani (LdRab2) to compensate for the growth of LdCen1-/- promastigotes. LdRab2 was isolated by protein pull-down from the parasite lysate, followed by nano-LC-MS/MS identification. The RAB domain sequence and the functional binding partners of the LdRab2 protein were predicted via Search Tool for the Retrieval of Interacting Proteins (STRING) analysis. The closeness of the LdRab2 protein to other reported centrin-binding proteins with different functions in other organisms was analyzed via phylogenetic analysis. Furthermore, in vitro and in silico analyses revealed that LdRab2 also interacts with other L. donovani centrins 3-5. Since centrin is a calcium-binding protein, we further investigated calcium-based interactions and found that the binding of LdRab2 to LdCen1 and LdCen4 is calcium-independent, whereas the interactions with LdCen3 and LdCen5 are calcium-dependent. The colocalization of LdCen1 and LdRab2 at the cellular basal-body region by immunofluorescence supports their possible functional association. The elevated expression of the LdRab2 protein in the mutant promastigotes suggested a probable role in compensating for the promastigote growth of this mutant strain, probably in association with other parasite centrins.

Half a century of Japanese research on two Neglected Tropical Diseases (trypanosomiasis and leishmaniasis): Overseas scientific cooperation.

Trypanosoma and Leishmania species are responsible of a range of Neglected Tropical Diseases (NTDs) from disfiguring conditions to fatal processes in humans. Both genera also affect wild and domestic animals causing diseases of public health significance and high economic impact on farm economy of developing areas. Japan has been actively involved in overseas cooperation and the country has a large scientific community. However, there is no information on the scientific output of Japanese scientists and institutions on these two NTDs. To explore the Japanese contribution and its profile, we have mined Web of Science database from 1971 to 2022 the articles by Japanese scientists, scientific areas and institutions, time-related variations of these parameters, and involvement in cooperation activities with foreign scientists. Research on Trypanosoma has been present in all the studied period, with higher production, whereas Leishmania-related activities showed a delay. A steady increased of Japanese scientific output was found up to the beginning of 2000s, whereas a certain stagnation was found in the present century. Low growth rate of research output on these two NTDs by Japanese authors in the 21st century is not correlated neither to the pattern found globally nor the situation in other parasitic infections. Thus, other elements should be considered in future analysis including the actual number of scientists involved and the available funding. Reinforcement of research groups from Japanese institutions and widening the scope of collaborations, particularly with health and academic centers from endemic regions, could trigger the Japanese productivity in the research area.

First detection of Leishmania major in dogs living in an endemic area of zoonotic cutaneous leishmaniasis in Tunisia.

BACKGROUND: Dogs are considered the main domestic animals that may be a reservoir for Leishmania infantum, the agent of zoonotic visceral leishmaniasis (ZVL) in several countries of the world. The dog may host other Leishmania species, but its epidemiological role in the maintenance and spreading of these parasites is not completely elucidated. Zoonotic cutaneous leishmaniasis (ZCL), caused by Leishmania major, affects thousands of people every year and is particularly diffused in many countries of North Africa and Middle East Asia. In ZCL endemic countries, few reports of L. major-positive dogs have been reported, probably because most human cases occur in poor rural areas where the social role of the dog and its medical management is not well considered. The aim of the present study is to better understand the possible involvement of domestic dogs in the epidemiology of ZCL. METHODS: Our research focused on a well-established endemic focus of ZCL, in the area of Echrarda, Kairouan Governorate, central Tunisia. A total of 51 dogs with no or mild clinical signs of vector borne diseases were selected in small villages where human cases of ZCL are yearly present. All dogs were sampled for the Leishmania spp. diagnosis, by using the following procedures: blood sample for serology and buffy coat quantitative polymerase chain reaction (qPCR), popliteal fine needle aspiration, and cutaneous biopsy punch for lymph node and skin qPCR. RESULTS: The results demonstrated a high percentage (21.6%) of dogs positive at least at one or more test; the most sensitive technique was the lymph node qPCR that detected 8/11 positive dogs. Nine, out of the eleven positive dogs, resulted as infected by Leishmania infantum; ITS1-PCR-sequencing allowed Leishmania major identification in the remaining two cases, both from the popliteal lymph node samples, which can suggest a possible visceral spread of a cutaneous Leishmania species in the dog. Interestingly, one of the two L. major-positive dogs was living in the same house where 6-year-old children showed cutaneous lesions referred to as ZCL. CONCLUSIONS: To our knowledge, this is the first report of L. major-positive dogs in Tunisia, the  epidemiological role of which remains under investigation.

Bioassay-guided Fractionation of Anti-Leishmania amazonensis Extracts from Ampelozizyphus amazonicus by High-speed Countercurrent Chromatography.

Ampelozizyphus amazonicus Ducke, known as "saracura-mirá" in the Amazon rainforest, is valued for its traditional use in malaria prevention and treatment. The plant's roots and bark are employed for these purposes, while the wood is often overlooked. Given the global importance of leishmaniasis, research focused on A. amazonicus anti-Leishmania amazonensis potential. The ethyl acetate extract from the bark (EAEB) exhibited the most effective inhibition of intracellular amastigote growth with IC50 7.0 µg.mL-1 but showed high toxicity (CC50 9.0 µg.mL-1). The wood ethanol (EW) and ethyl acetate (EAEW) extracts demonstrated promising results against L. amazonensis with IC50 15.8 µg.mL-1 and 10.0 µg.mL-1, CC50 50.5 µg.mL-1 and 22.7 µg.mL-1, respectively. High-speed countercurrent chromatography combined with mass spectrometry  off-line detection was employed for the bioassay-guided fractionation of EAEB and EAEW using HEMWat as solvent system. These extracts showed to be rich in saponins and triterpenes, besides minor glycosylated flavonoids. HSCCC was effective in obtaining high purity fractions, leading to the identification of a di-glycosylated triterpene saponin from EAEB, and melaleucic acid from EAEW. These findings highlight A. amazonicus as a potential source for developing new therapeutic alternatives for leishmaniasis and HSCCC as a technique enabling better separation efficiency of complex saponin matrices.

Emerging Leishmania donovani Lineages Associated with Cutaneous Leishmaniasis, Himachal Pradesh, India, 2023.

The clinical manifestation of leishmaniasis has historically been determined by the Leishmania species involved. However, recent emergence of novel Leishmania lineages has caused atypical pathologies. We isolated and characterized 2 new Leishmania donovani parasites causing cutaneous leishmaniasis in Himachal Pradesh, India.

Association of Intestinal Helminthiasis with Disseminated Leishmaniasis, Brazil.

Disseminated leishmaniasis is an emerging clinical form of Leishmania braziliensis infection. Evidence shows that co-infection by L. braziliensis and intestinal helminths does not affect clinical manifestations or response to therapy in cutaneous leishmaniasis patients. We evaluated whether co-infection was associated with those aspects in disseminated leishmaniasis patients in Brazil.

Autochthonous Leishmaniasis Caused by Leishmania tropica, Identified by Using Whole-Genome Sequencing, Sri Lanka.

Cutaneous leishmaniasis is atypical in Sri Lanka because Leishmania donovani, which typically causes visceral disease, is the causative agent. The origins of recently described hybrids between L. donovani and other Leishmania spp. usually responsible for cutaneous leishmaniasis remain unknown. Other endemic dermotropic Leishmania spp. have not been reported in Sri Lanka. Genome analysis of 27 clinical isolates from Sri Lanka and 32 Old World Leishmania spp. strains found 8 patient isolates clustered with L. tropica and 19 with L. donovani. The L. tropica isolates from Sri Lanka shared markers with strain LtK26 reported decades ago in India, indicating they were not products of recent interspecies hybridization. Because L. tropica was isolated from patients with leishmaniasis in Sri Lanka, our findings indicate L. donovani is not the only cause of cutaneous leishmaniasis in Sri Lanka and potentially explains a haplotype that led to interspecies dermotropic L. donovani hybrids.