Detection of Leishmania RNA Virus 2 (LRV2) among Clinical Isolates of Leishmania Major in Four Endemic Regions of Iran

PURPOSE

Leishmania RNA viruses (LRV) are double-stranded RNA viruses (dsRNA viruses) that play a role in the pathogenesis of Leishmania parasites. Cutaneous leishmaniasis (CL) is endemic in various parts of Iran. Our aimed was to investigate presence of LRV among the Leishmania major isolates in four endemic regions of Iran.

METHODS

In a cross-sectional study, we assessed the presence of LRV1 and LRV2 in 181 clinical isolates of L. major from four endemic cities in Iran using reverse transcription polymerase chain reaction (RT-PCR). After RNA extraction and cDNA synthesis, RT-PCR tests were conducted with LRV1 and LRV2 specific primers. Human beta-actin and kmp genes served as internal and external controls, respectively, and the Allele ID software was used to optimize melting curves.

RESULTS

LRV2 was detected in 27.6% (50 out of 181) of L. major isolates, while no LRV1 was found. We did not observe a statistically significant difference in the presence of LRV2 based on age group, number, or location of lesions.

CONCLUSION

This study confirms the presence of LRV2 in clinical isolates of L. major from endemic regions of Iran. Further researches with larger sample sizes is recommended to explore the association between LRV and clinical symptoms as well as treatment response.

Microbial Matryoshka: Addressing the Relationship between Pathogenic Flagellated Protozoans and Their RNA Viral Endosymbionts (Family Totiviridae)

Three genera of viruses of the family Totiviridae establish endosymbiotic associations with flagellated protozoa responsible for parasitic diseases of great impact in the context of One Health. Giardiavirus, Trichomonasvirus, and Leishmaniavirus infect the protozoa Giardia sp., Trichomonas vaginalis, and Leishmania sp., respectively. In the present work, we review the characteristics of the endosymbiotic relationships established, the advantages, and the consequences caused in mammalian hosts. Among the common characteristics of these double-stranded RNA viruses are that they do not integrate into the host genome, do not follow a lytic cycle, and do not cause cytopathic effects. However, in cases of endosymbiosis between Leishmaniavirus and Leishmania species from the Americas, and between Trichomonasvirus and Trichomonas vaginalis, it seems that it can alter their virulence (degree of pathogenicity). In a mammalian host, due to TLR3 activation of immune cells upon the recognition of viral RNA, uncontrolled inflammatory signaling responses are triggered, increasing pathological damage and the risk of failure of conventional standard treatment. Endosymbiosis with Giardiavirus can cause the loss of intestinal adherence of the protozoan, resulting in a benign disease. The current knowledge about viruses infecting flagellated protozoans is still fragmentary, and more research is required to unravel the intricacies of this three-way relationship. We need to develop early and effective diagnostic methods for further development in the field of translational medicine. Taking advantage of promising biotechnological advances, the aim is to develop ad hoc therapeutic strategies that focus not only on the disease-causing protozoan but also on the virus.

Diversity and dissemination of viruses in pathogenic protozoa

Viruses are the most abundant biological entities on Earth and play a significant role in the evolution of many organisms and ecosystems. In pathogenic protozoa, the presence of viruses has been linked to an increased risk of treatment failure and severe clinical outcome. Here, we studied the molecular epidemiology of the zoonotic disease cutaneous leishmaniasis in Peru and Bolivia through a joint evolutionary analysis of Leishmania braziliensis and their dsRNA Leishmania virus 1. We show that parasite populations circulate in tropical rainforests and are associated with single viral lineages that appear in low prevalence. In contrast, groups of hybrid parasites are geographically and ecologically more dispersed and associated with an increased prevalence, diversity and spread of viruses. Our results suggest that parasite gene flow and hybridization increased the frequency of parasite-virus symbioses, a process that may change the epidemiology of leishmaniasis in the region.

Evolution of RNA viruses in trypanosomatids: new insights from the analysis of Sauroleishmania

RNA viruses play an important role in Leishmania biology and virulence. Their presence was documented in three (out of four) Leishmania subgenera. Sauroleishmania of reptiles remained the only underinvestigated group. In this work, we analyzed the viral occurrence in Sauroleishmania spp. and detected RNA viruses in three out of seven isolates under study. These viruses were of two families-Narnaviridae and Totiviridae. Phylogenetic inferences demonstrated that totiviruses from L. adleri and L. tarentolae group together within a larger cluster of LRV2s, while a narnavirus of L. gymnodactyli appeared as a phylogenetic relative of narnaviruses of Blechomonas spp. Taken together, our work not only expanded the range of trypanosomatids that can host RNA viruses but also shed new light on the evolution and potential routes of viral transmission in these flagellates.

First report of putative Leishmania RNA virus 2 (LRV2) in Leishmania infantum strains from canine and human visceral leishmaniasis cases in the southeast of Brazil

BACKGROUND

Leishmania RNA virus 1 (LRV1) is commonly found in South American Leishmania parasites belonging to the subgenus Viannia, whereas Leishmania RNA virus 2 (LRV2) was previously thought to be restricted to the Old-World pathogens of the subgenus Leishmania.

OBJECTIVES

In this study, we investigated the presence of LRV2 in strains of Leishmania (L.) infantum, the causative agent of visceral leishmaniasis (VL), originating from different hosts, clinical forms, and geographical regions.

METHODS

A total of seventy-one isolates were screened for LRV2 using semi-nested reverse transcription-polymerase chain reaction (RT-PCR) targeting the RNA-dependent RNA polymerase (RdRp) gene.

FINDINGS

We detected LRV2 in two L. infantum isolates (CUR268 and HP-EMO) from canine and human cases, respectively.

MAIN CONCLUSIONS

To the best of our knowledge, this is the first detection of LRV2 in the New World.

Parasite hybridization promotes spreading of endosymbiotic viruses

Viruses are the most abundant biological entities on Earth and play a significant role in the evolution of many organisms and ecosystems. In pathogenic protozoa, the presence of endosymbiotic viruses has been linked to an increased risk of treatment failure and severe clinical outcome. Here, we studied the molecular epidemiology of the zoonotic disease cutaneous leishmaniasis in Peru and Bolivia through a joint evolutionary analysis of Leishmania braziliensis parasites and their endosymbiotic Leishmania RNA virus. We show that parasite populations circulate in isolated pockets of suitable habitat and are associated with single viral lineages that appear in low prevalence. In contrast, groups of hybrid parasites were geographically and ecologically dispersed, and commonly infected from a pool of genetically diverse viruses. Our results suggest that parasite hybridization, likely due to increased human migration and ecological perturbations, increased the frequency of endosymbiotic interactions known to play a key role in disease severity.

Revisiting epidemiology of leishmaniasis in central Asia: lessons learnt

In this work we reviewed historical and recent data on Leishmania spp. infection combining data collected in Turkmenistan, Uzbekistan, Kazakhstan, Kyrgyzstan, Iran, China and Mongolia. We specifically focused on a complex of co-existing species (Leishmania major, Leishmania turanica and Leishmania gerbilli) sharing the same animal reservoirs and vectors. In addition, we analysed the presence of dsRNA viruses in these species and discussed future research directions to identify species-specific traits, which may determine susceptibility of different Leishmania spp. to viral infection.

Widespread, human-associated redondoviruses infect the commensal protozoan Entamoeba gingivalis

Redondoviruses are circular Rep-encoding single-stranded DNA (CRESS) viruses of high prevalence in healthy humans. Redondovirus abundance is increased in oro-respiratory samples from individuals with periodontitis, acute illness, and severe COVID-19. We investigated potential host cells supporting redondovirus replication in oro-respiratory samples and uncovered the oral amoeba Entamoeba gingivalis as a likely host. Redondoviruses are closely related to viruses of Entamoeba and contain reduced GC nucleotide content, consistent with Entamoeba hosts. Redondovirus and E. gingivalis co-occur in metagenomic data from oral disease and healthy human cohorts. When grown in xenic cultures with feeder bacteria, E. gingivalis was robustly positive for redondovirus RNA and DNA. A DNA proximity-ligation assay (Hi-C) on xenic culture cells showed enriched cross-linking of redondovirus and Entamoeba DNA, supporting E. gingivalis as the redondovirus host. While bacteria are established hosts for bacteriophages within the human virome, this work shows that eukaryotic commensals also contribute an abundant human-associated virus.

Characterisation of Trichomonas vaginalis Isolates Collected from Patients in Vienna between 2019 and 2021

Trichomonas vaginalis (TV) is the causative agent of trichomoniasis, the most common nonviral sexually transmitted disease. TV can carry symbionts such as Trichomonas vaginalis virus (TVV) or Mycoplasma hominis. Four distinct strains of TV are known: TVV1, TVV2, TVV3, and TVV4. The aim of the current study was to characterise TV isolates from Austrian patients for the presence of symbionts, and to determine their effect on metronidazole susceptibility and cytotoxicity against HeLa cells. We collected 82 TV isolates and detected presence of TVV (TVV1, TVV2, or TVV3) in 29 of them (35%); no TVV4 was detected. M. hominis was detected in vaginal/urethral swabs by culture in 37% of the TV-positive patients; M. hominis DNA was found in 28% of the TV isolates by PCR. In 15% of the patients, M. hominis was detected in the clinical samples as well as within the respective TV isolates. In 22% of the patients, M. hominis was detected by culture only. In 11 patients, M. hominis was detected only within the respective cultured TV isolates (13%), while the swab samples were negative for M. hominis. Our results provide a first insight into the distribution of symbionts in TV isolates from Austrian patients. We did not observe significant effects of the symbionts on metronidazole susceptibility, cytotoxicity, or severity of symptoms.

Successful Isolation of Leishmania RNA Virus (LRV) from Leishmania major in a Cutaneous Leishmaniasis Focus in Central Iran: An Update on Cases

Purpose

Cutaneous leishmaniasis (CL) is a major vector-borne disease that affects people globally, including Iran. Different factors are associated with leishmaniasis pathogenicity; recently, a link of the possible relationship between Leishmania RNA Virus (LRV) and disease severity was proposed, especially in the New World leishmaniasis (NWL). This study was aimed to investigate the presence of LRV2 in Leishmania isolates in Aran o Bidgol, Isfahan province.

Methods

Samples were collected from 110 CL-suspected patients referred to the health center. In this study, we aimed to investigate CL cases (parasitologically and clinically), identify Leishmania species (by ITS1-PCR–RFLP), and finally detection of LRV2 (by RdRp-semi-nested PCR).

Results

Parasitological methods showed 60 positive cases, based on the HaeIII enzyme restriction profile, 59 cases were caused by L. major and 1 case by L. tropica. Our project is the first study on LRV2 isolation in Aran o Bidgol city and the LRV was successfully detected from a single L. major isolated in a women’s hand lesion. Using BLAST, 94.8–100% similarity was observed in the RdRp sequence of current LRV isolate with those available in GenBank from Iran or overseas.

Conclusion

L. major was the main cause of CL in Aran o Bidgol, although L. tropica is also present in a much lower proportion in the area. This is the first report on the presence of LRV2 in Aran o Bidgol and the fifth in Iran.

Prevalence of Leishmania RNA virus in Leishmania parasites in patients with tegumentary leishmaniasis: A systematic review and meta-analysis

Background

Cutaneous leishmaniasis is caused by different protozoan parasites of the genus Leishmania. Leishmania RNA virus (LRV) was identified as the first Leishmania infecting virus in 1998. Different studies showed the presence and role of the LRV in Leishmania parasites causing cutaneous leishmaniasis (CL). However, there is limited data on the pooled prevalence of LRV in Leishmania parasites causing CL. Therefore, the aim of this systematic review and meta-analysis was to determine the pooled prevalence of LRV in Leishmania parasite isolates and/or lesion biopsies in patients with CL from the available literature globally.

Methodology

We retrieved the studies from different electronic databases. The studies were screened and identified based on the inclusion and exclusion criteria. We excluded studies exclusively done in experimental animals and in vitro studies. The review was conducted in line with PRISMA guidelines. The meta-analysis was performed with Stata software version 14 with metan command. The forest plot with random-effect model was used to estimate the pooled prevalence with 95% confidence interval. Inverse variance index (I²) was used to assess the heterogeneity among the included articles.

Principal findings

A total of 1215 samples from 25 studies were included. Of these, 40.1% (487/1215) were positive for LRV. The overall pooled prevalence of LRV globally was 37.22% (95% CI: 27.54% - 46.90%). The pooled prevalence of LRV in the New World (NW) and Old World (OW) regions was 34.18% and 45.77%, respectively. Leishmania guyanensis, L. braziliensis, L. major, and L. tropica were the most studied species for the detection of LRV. The prevalence of LRV from Leishmania isolates and lesion biopsies was 42.9% (349/813) and 34.3% (138/402), respectively.

Conclusion

This systematic study revealed that there is high prevalence of LRV in Leishmania parasites isolated from patients with CL. More comprehensive studies would be required to investigate the presence of the LRV in other Leishmania species such as L. aethiopica to fully understand the role of LRV in different clinical manifestations and disease pathology presented in CL patients.

Cutaneous leishmaniasis (CL) is among the most neglected tropical diseases affecting a significant proportion of the world population, impacting mostly on the poorest communities. CL can present as localized, mucocutaneous or diffuse cutaneous. There are various reports on the prevalence of Leishmania RNA virus (LRV) in Leishmania parasites and/or lesion biopsies in patients with CL from both the Old World and New World regions. However, there is scarcity of comprehensive knowledge on the pooled prevalence of the virus in Leishmania parasites causing human CL. We searched different electronic databases and Google Scholar for published articles aimed to determine the presence of LRV in Leishmania parasites and/or lesion biopsies in patients with CL globally. The retrieved articles were screened according to the inclusion and exclusion parameters. Data was extracted based on the PRISMA guideline by reviewing the selected articles. Systematic review and meta-analysis would be one way to improve the level of evidence by providing pooled prevalence of the individual single studies regarding the presence of LRV in Leishmania parasites and/or lesion biopsies. This systematic review and meta-analysis revealed that a large proportion of the Leishmania parasites causing human CL harbour the endosymbiotic LRV. Further studies are needed to better understand the role of the virus in the clinical presentation of CL, as a potential target of treatment and vaccine development especially in Old World Leishmania parasites like L. aethiopica.

Increasing the Sensitivity of Leishmania RNA Virus 2 (LRV2) Detection with a Modification in cDNA Synthesis

OBJECTIVE

Leishmania RNA virus was detected the first time in the New World Leishmania species. Recent studies were also showed the presence of Leishmania RNA virus 2 (LRV2) in Old Word Leishmania species including Turkish L. major and L. tropica isolates. This study aimed to increase the sensitivity of qPCR with a modification in the denaturation step of cDNA preparation protocol.

METHODS

In this study, LRV2+ three L. major, two L. tropica strains and L. major control strain (MHOM/SU/73/5-ASKH) were included. Total RNA isolation was done using different numbers of Leishmania promastigotes (10⁸, 10⁵ and 10³). Before cDNA synthesis, samples were denatured at 95 °C for 2 min, as a modification of the kit procedure. qPCR was undertaken using 0.5 mM primers (LRV F-HR/LRV R-HR) diluted in SYBR Green Master mix.

RESULTS

We observed lower Ct values in amplicons with the modified version than with the classical kit protocol for cDNA synthesis, in all of the strains used in the study. The addition of pre-denaturation step at 95 °C showed lower Ct values meaning the sensitivity increased. Different parasite dilutions showed similar results.

CONCLUSION

It is important to increase the sensitivity especially with the aim for detecting LRV in clinical samples obtained from patients probably have less number of parasites. The presence and burden of the virus can help to understand the relationship between the clinical findings and the pathogenicity of the parasite which may lead to changes in the course of treatment.

Identification of Endosymbiotic Virus in Small Extracellular Vesicles Derived from Trichomonas vaginalis

Accumulated evidence suggests that the endosymbiotic Trichomonasvirus (TVV) may play a role in the pathogenesis and drug susceptibility of Trichomonas vaginalis. Several reports have shown that extracellular vesicles (EVs) released from TVV-positive (TVV+) trichomonads can modulate the immune response in human vaginal epithelial cells and animal models. These results prompted us to examine whether EVs released from TVV+ isolates contained TVV. We isolated small extracellular vesicles (sEVs) from six T. vaginalis isolates that were either TVV free (ATCC 50143), harbored a single (ATCC 30236, ATCC 30238, T1), two (ATCC PRA-98), or three TVV subspecies (ATCC 50148). The presence of TVV subspecies in the six isolates was observed using reverse transcription-polymerase chain reaction (RT-PCR). Transmission electron microscopy (TEM) confirmed the presence of cup-shaped sEVs with a size range from 30–150 nm. Trichomonas vaginalis tetraspanin (TvTSP1; TVAG_019180), the classical exosome marker, was identified in all the sEV preparations. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis showed that all the sEVs isolated from TVV+ isolates contain viral capsid proteins derived from the same TVV subspecies in that isolate as demonstrated by RT-PCR. To provide more comprehensive information on the TVV subspecies population in other T. vaginalis isolates, we investigated the distribution of TVV subspecies in twenty-four isolates by mining the New-Generation Sequencing (NGS) RNAseq datasets. Our results should be beneficial for future studies investigating the role of TVV on the pathogenicity of T. vaginalis and the possible transmission of virus subspecies among different isolates via sEVs.

Molecular identification of Leishmania RNA virus in cutaneous leishmaniasis patients and rodent reservoirs in Isfahan province, Iran

Leishmania RNA virus (LRV) is a double-strand RNA virus that was first detected in members of the Leishmania viannia in the New World. The present study aimed to investigate the presence of LRV in the Leishmania species isolated from cutaneous leishmaniasis (CL) patients and rodents as reservoirs in Isfahan province an old zoonotic CL focus, center of Iran. Totally, 85 samples were collected from CL patients (n = 80) and rodent reservoirs (n = 5) from different regions of Isfahan province. Species identification was determined using the PCR-RFLP method. Viral dsRNA was extracted and for observation of 5.3 kb dsRNA on an agarose gel. The presence of LRV was surveyed using the Semi-nested PCR method. For phylogenetic analyzes, 6 samples of 13 isolates were sequenced and a phylogenetic tree was drawn by MEGA7 version 7.0.26. Of 80 Leishmania isolates recovered from the patients with CL, 79 and only one were identified as L. major and L. tropica, respectively. Also, the PCR assays detected four L. major and one L. turanica in five assessed Rhombomys opimus as the rodent reservoirs. LRV was detected only in Leishmania species isolated from 13 species of 85 (15.3%) CL including (L. major, n = 12) and (L. tropica, n = 1). Phylogenetic analysis showed that they were belonged to LRV2 and had the highest similarity with Iranian reference LRV2 in GenBank. Our results showed that the LRV2 was present in cutaneous Leishmania species in Isfahan province is the most historical and touristic province of Iran. In the study LRV was not reported from rodent reservoirs, it may be due to the small sample size. Phylogenetic analysis of current sequences demonstrated that these isolates belong to the registered LRV2 of the Old World.

Analyses of Leishmania-LRV Co-Phylogenetic Patterns and Evolutionary Variability of Viral Proteins

Leishmania spp. are important pathogens causing a vector-borne disease with a broad range of clinical manifestations from self-healing ulcers to the life-threatening visceral forms. Presence of Leishmania RNA virus (LRV) confers survival advantage to these parasites by suppressing anti-leishmanial immunity in the vertebrate host. The two viral species, LRV1 and LRV2 infect species of the subgenera Viannia and Leishmania, respectively. In this work we investigated co-phylogenetic patterns of leishmaniae and their viruses on a small scale (LRV2 in L. major) and demonstrated their predominant coevolution, occasionally broken by intraspecific host switches. Our analysis of the two viral genes, encoding the capsid and RNA-dependent RNA polymerase (RDRP), revealed them to be under the pressure of purifying selection, which was considerably stronger for the former gene across the whole tree. The selective pressure also differs between the LRV clades and correlates with the frequency of interspecific host switches. In addition, using experimental (capsid) and predicted (RDRP) models we demonstrated that the evolutionary variability across the structure is strikingly different in these two viral proteins.

The Maze Pathway of Coevolution: A Critical Review over the Leishmania and Its Endosymbiotic History

The description of the genus Leishmania as the causative agent of leishmaniasis occurred in the modern age. However, evolutionary studies suggest that the origin of Leishmania can be traced back to the Mesozoic era. Subsequently, during its evolutionary process, it achieved worldwide dispersion predating the breakup of the Gondwana supercontinent. It is assumed that this parasite evolved from monoxenic Trypanosomatidae. Phylogenetic studies locate dixenous Leishmania in a well-supported clade, in the recently named subfamily Leishmaniinae, which also includes monoxenous trypanosomatids. Virus-like particles have been reported in many species of this family. To date, several Leishmania species have been reported to be infected by Leishmania RNA virus (LRV) and Leishbunyavirus (LBV). Since the first descriptions of LRVs decades ago, differences in their genomic structures have been highlighted, leading to the designation of LRV1 in L. (Viannia) species and LRV2 in L. (Leishmania) species. There are strong indications that viruses that infect Leishmania spp. have the ability to enhance parasitic survival in humans as well as in experimental infections, through highly complex and specialized mechanisms. Phylogenetic analyses of these viruses have shown that their genomic differences correlate with the parasite species infected, suggesting a coevolutionary process. Herein, we will explore what has been described in the literature regarding the relationship between Leishmania and endosymbiotic Leishmania viruses and what is known about this association that could contribute to discussions about the worldwide dispersion of Leishmania.

Characterization of a new Leishmania major strain for use in a controlled human infection model

Leishmaniasis is widely regarded as a vaccine-preventable disease, but the costs required to reach pivotal Phase 3 studies and uncertainty about which candidate vaccines should be progressed into human studies significantly limits progress in vaccine development for this neglected tropical disease. Controlled human infection models (CHIMs) provide a pathway for accelerating vaccine development and to more fully understand disease pathogenesis and correlates of protection. Here, we describe the isolation, characterization and GMP manufacture of a new clinical strain of Leishmania major. Two fresh strains of L. major from Israel were initially compared by genome sequencing, in vivo infectivity and drug sensitivity in mice, and development and transmission competence in sand flies, allowing one to be selected for GMP production. This study addresses a major roadblock in the development of vaccines for leishmaniasis, providing a key resource for CHIM studies of sand fly transmitted cutaneous leishmaniasis.

Viruses of protozoan parasites and viral therapy: Is the time now right?

Infections caused by protozoan parasites burden the world with huge costs in terms of human and animal health. Most parasitic diseases caused by protozoans are neglected, particularly those associated with poverty and tropical countries, but the paucity of drug treatments and vaccines combined with increasing problems of drug resistance are becoming major concerns for their control and eradication. In this climate, the discovery/repurposing of new drugs and increasing effort in vaccine development should be supplemented with an exploration of new alternative/synergic treatment strategies. Viruses, either native or engineered, have been employed successfully as highly effective and selective therapeutic approaches to treat cancer (oncolytic viruses) and antibiotic-resistant bacterial diseases (phage therapy). Increasing evidence is accumulating that many protozoan, but also helminth, parasites harbour a range of different classes of viruses that are mostly absent from humans. Although some of these viruses appear to have no effect on their parasite hosts, others either have a clear direct negative impact on the parasite or may, in fact, contribute to the virulence of parasites for humans. This review will focus mainly on the viruses identified in protozoan parasites that are of medical importance. Inspired and informed by the experience gained from the application of oncolytic virus- and phage-therapy, rationally-driven strategies to employ these viruses successfully against parasitic diseases will be presented and discussed in the light of the current knowledge of the virus biology and the complex interplay between the viruses, the parasite hosts and the human host. We also highlight knowledge gaps that should be addressed to advance the potential of virotherapy against parasitic diseases.

Presence and diversity of Leishmania RNA virus in an old zoonotic cutaneous leishmaniasis focus, northeastern Iran: haplotype and phylogenetic based approach

OBJECTIVE

Leishmania RNA virus (LRV) is a double-stranded RNA (dsRNA) virus that circulates within many species of the Leishmania parasite. In this study, we aimed to investigate the presence of LRV2 circulating in Leishmania isolates in an old focus of ZCL located in northeastern of Iran.

METHODS

Leishmania isolates were collected from 85 patients that confirmed to have cutaneous leishmaniasis (CL) based on parasitological examination. To identify the Leishmania isolates, species-specific primer sets were applied for molecular identification. The presence of LRV2 was performed by RdRp-semi nested-PCR. The genetic diversity were calculated using MEGA and DnaSP. To assess haplotype diversity, 31 LRV2 strains in different regions were surveyed using analysis a 292-bp section of the RdRp sequences.

RESULTS

Out of 85 patients, 83 (97.6 %) were diagnosed with L. major and 2 (2.4 %) with L. tropica. LRV2 virus was detected in 59 (69.4%) of the CL cases. For the first time, LRV2 was reported in one L. tropica strain in Iran. The current LRV2 sequences indicated the highest similarities to an Old World LRV2. Moreover, 10 unique haplotypes were identified based on the analyzed sequences of the RdRp gene.

CONCLUSIONS

Our results indicated the highest occurrence of Leishmania/LRV2 co-circulation in this known ZCL focus from northeastern Iran. Phylogenetic analyses of LRV2 sequences confirmed that these isolates belong to the order of LRV2 from the Old World. This study offered an insight into LRV2 haplotype that the informative issue can be used for genetic research of LRV2 in other regions.