Molecular Diagnosis of Human Cutaneous Leishmaniasis and Identification of the Causative Leishmania Species in Iran: A Narrative Review

Cutaneous leishmaniasis (CL) is a common form of leishmaniasis in underdeveloped countries. Although CL tends to be self-limiting, it can cause significant scars and may progress to more severe manifestations. Additionally, Leishmania species vary in susceptibility to the available treatments. The selection of treatment and clinical outcome of CL depend on the accurate determination of the Leishmania species. This mini-review aims to provide an overview of the molecular diagnosis techniques such as PCR-based assays, nucleic acid sequence-based amplification, and loop-mediated isothermal amplification utilized in the identification of Leishmania species in Iran.

Clinical polymorphism of zoonotic cutaneous leishmaniasis: combination of the clinical and the parasitological diagnosis

Zoonotic cutaneous leishmaniasis (ZCL) is a neglected tropical disease caused by Leishmania (L.) major. This zoonosis is characterized by a broad-spectrum clinical polymorphism and may be underestimated and poorly treated since it is a simulator of various dermatoses. The aim of our study was to analyze the clinical polymorphism of patients with ZCL. A total of 142 patients with confirmed CL based on the microscopic examination of skin lesion biopsies were included in this study. Molecular typing of Leishmania species revealed that all patients were infected with L. major. In total, 14 clinical forms were observed. Six were typical and eight were atypical. The typical ZCL forms are grouped as follows: papular (26.76%), ulcero-crusted (26.05%), ulcerated (13.38%), impetiginous (9.86%), nodular (9.15%), and papulo-nodular (5.63%) lesions. In atypical ZCL forms, we described erythematous (2.81%), erysipeloid (1.4%), sporotrichoid, (1.4%), keratotic (0.7%) lupoid (0.7%), lichenoid (0.7%), psoriasiform (0.7%), and zosteriform (0.7%) lesions. Here, the lichenoid and the keratotic forms caused by L. major were reported for the first time in Tunisia. These findings will help physicians to be aware of the unusual lesions of ZCL that could be confused with other dermatological diseases. For this reason, it will be necessary to improve the diagnosis of CL especially in endemic areas. Such large clinical polymorphism caused by L. major may be the result of a complex association between the vector microbiota, the parasite, and the host immune state, and further studies should be carried out in order to reveal the mechanisms involved in clinical polymorphism of ZCL.

Geographical and Molecular Analysis of Haplotype Variations in Leishmania major Among Infected Iranian Phlebotomus papatasi

PURPOSE

Leishmania major is main causative agent and Phlebotomus papatasi is only proven vector of Zoonotic Cutaneous Leishmaniasis (ZCL) in Iran. Human leishmaniasis is mostly susceptible to climatic conditions and molecular variations of Leishmania parasites within sandflies.

METHODS

L. major was analyzed based on geographical, environmental, climatic changes and haplotype variations within P. papatasi. Molecular tools and different geographical aspects were employed using Arc-GIS software for mapping the geographic distribution of samples and other statistics tests. Fragments of ITS-rDNA, k-DNA, and microsatellite genes of Leishmania were used for PCR, RFLP, sequencing, and phylogenetic analyses.

RESULTS

Totally 81 out of 1083 female P. papatasi were detected with Leishmania parasites: 70 and five were L. major and L. turanica, respectively. Golestan and Fars provinces had the highest (13.64%) and lowest (4.55%) infection rates, respectively. The infection rate among female P. papatasi collected from gerbil burrows was significantly higher (15.15%) than animal shelters, yards, and inside houses (4.48%) (P < 0.0%). Microsatellite was more sensitive (22.72%) than k-DNA (18.8%) and ITS-rDNA (7.48%). More molecular variations of L. major were found in Isfahan province.

CONCLUSIONS

Arc-GIS software and other statistics tests were employed to find Leishmania positive and haplotype variations among sand flies. Geographical situations, altitude, climate, precipitation, humidity, temperature, urbanization, migrations, regional divergences, deforestation, global warming, genome instability, ecology, and biology of the sand flies intrinsically, and the reservoir hosts and neighboring infected locations could be reasons for increasing or decreasing the rate of Leishmania infection and haplotype variations.

The healing effect of a mixture of Arnebia euchroma and animal fat on burn wounds in rats in comparison with sulfadiazine

OBJECTIVE

Thermal burn is a serious cause of morbidity and mortality that affects millions of people worldwide. The aim of this experimental study was to investigate the efficacy of Arnebia euchroma (AE) to treat burn wounds in a rat model.

METHOD

A total of 80 male rats (200-250g) were shaved over the back of the neck (2×3cm2) and a second-degree burn wound was induced at this site under general anaesthesia. The rats were then randomly assigned to one of four groups (each n=20) and the burns were treated daily for 14 days as follows: (1) dressed with animal fat; (2) dressed with sulfadiazine; (3) dressed with a mixture of AE and animal fat; (4) no treatment (control). Five rats from each group were sacrificed on days 3, 5, 9 and 14 post-burn and the wounds were evaluated histologically and immunohistochemically for the expression of interleukin (IL)-1 and IL-6.

RESULTS

There was a significant increase at day 3 and decrease on day 5 samples for the expression of IL-1 in the AE plus fat group and IL-6 in the AE plus fat and sulfadiazine groups, compared to the control and fat treatment groups, respectively. Both AE plus fat and sulfadiazine treatments reduced inflammation and granulation tissue formation by day 5 post-burn, while re-epithelialisation commenced by day 9 post-burn. In addition, burns treated with AE plus fat exhibited keratinised epidermis, associated with regular collagen fibres, compared to moderately dense collagen fibres without vascularisation in the sulfadiazine group.

CONCLUSION

These findings suggested that AE plus fat was superior to sulfadiazine in enhancing burn wound healing in rats.

Knowledge and Attitude Regarding Cutaneous Leishmaniasis Among Adult Population in Tabuk, Saudi Arabia

Background Cutaneous leishmaniasis (CL) is a major health problem in Saudi Arabia. It is caused by the protozoa Leishmania. The vector is female sand flies. In order to develop preventive strategies to reduce the burden of this health problem, public awareness of the disease should be assessed. Objective This study aimed to investigate the knowledge and attitude toward CL among the adult population in Tabuk, Saudi Arabia. Methods A cross-sectional survey study was conducted on 385 adult participants of Tabuk between April and May 2022. The investigators assembled the survey questions from peer-reviewed articles with some modifications. Google Forms was used to create the online survey. Social media were used to distribute the survey. Results The study revealed that hearing about CL was much more common among participants older than 61 years and Saudi males. The most prominent sources of information for the participants on which their answers were based were as follows: families and friends, health care professionals, television or radio, and lastly, newspapers. Subjects older than 61 years also showed more knowledge of the risk factors for contracting CL. However, the participants showed overall poor knowledge of the clinical presentation of the disease, which gender or age group was mostly affected, or how the disease was transmitted. Likewise, their knowledge of sand flies was poor. Most participants did not know if CL was a health problem or not. Conclusions The study revealed overall poor awareness of the epidemiological aspects of CL, how it is transmitted, its clinical presentation, and proper management. Our study could help authorities correct the gap in knowledge regarding CL in Tabuk.

PLGA Nanoparticles as New Drug Delivery Systems in Leishmaniasis Chemotherapy: A Review of Current Practices

Although leishmaniasis is one of the most common parasitic diseases, its traditional treatments suffer from some serious problems. To solve such issues, we can take advantage of the effective nanoparticle-based approaches to deliver anti-leishmanial agents into leishmania-infected macrophages either using passive targeting or using macrophagerelated receptors. Despite the high potential of nanotechnology, Liposomal Amphotericin B (AmBisome®) is the only FDA-approved nanoparticle-based anti-leishmanial therapy. In an effort to find more anti-leishmanial nano-drugs, this 2011-2021 review study aimed to investigate the in-vivo and in-vitro effectiveness of poly (lactic-co-glycolic acid) nanoparticles (PLGA-NPs) in the delivery of some traditional anti-leishmanial drugs. Based on the results, PLGA-NPs could improve solubility, controlled release, trapping efficacy, bioavailability, selectivity, and mucosal penetration of the drugs, while they decreased resistance, dose/duration of administration and organotoxicity of the agents. However, none of these nano-formulations have been able to enter clinical trials so far. We summarized the data about the common problems of anti-leishmanial agents and the positive effects of various PLGA nano-formulations on reducing these drawbacks under both in-vitro and in-vivo conditions in three separate tables. Overall, this study proposes two AmB-loaded PLGA with a 99% reduction in parasite load as promising nanoparticles for further studies.

The immune response in canine and human leishmaniasis and how this influences the diagnosis- a review and assessment of recent research

Leishmaniasis is a widespread but still underdiagnosed parasitic disease that affects both humans and animals. There are at least 20 pathogenic species of Leishmania, most of them being zoonotic. The diagnosis of leishmaniasis remains a major challenge, with an important role being played by the species of parasites involved, the genetic background, the immunocompetence of the host. This paper brings to the fore the sensitivity of the balance in canine and human leishmaniasis and addresses the importance of the host's immune response in establishing a correct diagnosis, especially in certain cases of asymptomatic leishmaniasis, or in the situation the host is immunosuppressed or acquired leishmaniasis through vertical transmission. The methods considered as a reference in the diagnosis of leishmaniasis no longer present certainty, the diagnosis being influenced mostly by the immune response of the host, which differs according to the presence of other associated diseases or even according to the breed in dogs. Consequently, the diagnosis and surveillance of leishmaniasis cases remains an open topic, requiring new diagnostic methods adapted to the immunological state of the host.

Diagnostic Tools for Cutaneous Leishmaniasis Caused by Leishmania donovani: A Narrative Review

Leishmaniasis, a neglected tropical disease, encompasses a spectrum of clinical conditions and poses a significant risk of infection to over one billion people worldwide. Visceral leishmaniasis (VL) in the Indian sub-continent (ISC), where the causative parasite is Leishmania donovani, is targeted for elimination by 2025, with some countries already reaching such targets. Other clinical phenotypes due to the same species could act as a reservoir of parasites and thus pose a challenge to successful control and elimination. Sri Lanka has consistently reported cutaneous leishmaniasis (CL) due to L. donovani as the primary disease presentation over several decades. Similar findings of atypical phenotypes of L. donovani have also been reported from several other countries/regions in the Old World. In this review, we discuss the applicability of different methods in diagnosing CL due to L. donovani and a comprehensive assessment of diagnostic methods spanning clinical, microscopic, molecular, and immunological approaches. By incorporating evidence from Sri Lanka and other regions on L. donovani-related CL, we thoroughly evaluate the accuracy, feasibility, and relevance of these diagnostic tools. We also discuss the challenges and complexities linked to diagnosing CL and review novel approaches and their applicability for detecting CL.

Investigation of antileishmanial activities of CaO nanoparticles on L. tropica and L. infantum parasites, in vitro

Stibogluconate sodium and meglumine antimoniate are the main antimonials utilised as the primary treatment option for leishmaniasis. However, have a number of side effects that limit their use. Development of nanoparticles (NPs) use in biological research and remarkable antimicrobial effects and unique optical and structural properties of CaO NPs have motivated this study to evaluated the effect of different times/dilutions of CaO NPs on Leishmania tropica and Leishmania infantum. To evaluate the antileishmanial activity of CaO NPs, the cytotoxic effect of CaO NPs against L. tropica and L. infantum amastigotes, promastigotes, as well as macrophages, was evaluated using counting and MTT assay after adding different concentrations of CaO nanoparticles (800-6.25 μg/ml) to the parasite culture. The possible apoptosis by CaO NPs were evaluated via flow cytometry assay. The XRD-pattern related to CaO nanoparticles indicating the cubic phase structures. According the effects of nanoparticle on promastigotes the IC50 values of CaO nanoparticles within 72 h were 19.81 μg/ml for L. tropica and 22.57 μg/ml for L. infantum. The percentage of the normal, apoptotic, and necrotic cells was estimated to be 82.6%, 14.81%, and 2.69% for L. tropica, and 73.6%, 23.89%, and 2.58% for L. infantum, respectively. Our results showed acceptable in vitro activity level of CaO NPs against L. tropica and L. infantum promastigotes as well as intracellular amastigotes. CaO NPs were more effective against L. infantum compared to L. tropica in vitro study.

The novel treatments based on tissue engineering, cell therapy and nanotechnology for cutaneous leishmaniasis

Cutaneous leishmaniasis (CL) is a global public health issue. Conventional treatments have substantial costs, side effects, and parasite resistance. Due to easy application and inexpensive cost, topical treatment is the optimal approach for CL. It could be used alone or with systemic treatments. Electrospun fibers as drug release systems in treating skin lesions have various advantages such as adjustable drug release rate, maintaining appropriate humidity and temperature, gas exchange, plasticity at the lesion site, similarity with the skin extracellular matrix (ECM) and drug delivery with high efficiency. Hydrogels are valuable scaffolds in the treatment of skin lesions. The important features of hydrogels include preserving unstable drugs from degradation, absorption of wound secretions, high biocompatibility, improving the re-epithelialization of the wound and preventing the formation of scars. One of the issues in local drug delivery systems for the skin is the low permeability of drugs in the skin. Polymeric scaffolds that are designed as microneedle patches can penetrate the skin and overcome this challenge. Also, drug delivery using nanocarriers increases the effectiveness of drugs in lower and more tolerable doses and reduces the toxicity of drugs. The application of cell therapy in the treatment of parasitic and infectious diseases has been widely investigated. The complexity of leishmaniasis treatment requires identifying new treatment options like cell therapy to overcome the disease. Topics investigated in this study include drug delivery systems based on tissue engineering scaffolds, nanotechnology and cell therapy-based studies to reduce the complications of CL.

Superparamagnetic Iron Oxide-Labeled Leishmania major Can Be Traced in Fibroblasts

Introduction

Leishmaniasis is still a neglected tropical disease that can endanger more than 350 million people among 98 countries. Leishmania can survive in fibroblasts as latent inactive forms. This study was conducted to evaluate the role of superparamagnetic iron oxide nanoparticles (SPIONs) in cell culture for tracking the labeled Leishmania major in fibroblasts.

Methods

Dextran-coated SPIONs were used for labeling L. major in co-culture of fibroblasts with the parasite. To quantify and trace SPION-labeled Leishmania, Prussian blue staining was undertaken. Fibroblast characterization was undertaken by real time polymerase chain reaction. Transmission electron microscope (TEM) was used for confirming the entry of the labeled L. major to the cytoplasm and the nucleus of the fibroblast.

Results

Fibroblasts were spindle-shaped and adherent to culture flasks. Promastigotes were with thin elongated lance-like morphology with an anterior kinetoplast and an emergent free flagellum. Prussian blue staining revealed that internalized SPIONs were localized within cytoplasm and nucleus of the fibroblasts after 24 hours of culture. Prussian blue staining successfully showed the presence of iron (stained blue) in labeled L. major within the fibroblasts. This finding was confirmed by TEM, and labeled L. major was detected in the fibroblast cytoplasm and nucleus too.

Conclusion

We can conclude that SPIONs are safe, inexpensive, easy to use, and accurate, and a fast method to label Leishmania parasite in cells that the parasite can be latent, such as fibroblasts. These findings can open a new window in diagnosis, pathogenesis, and treatment of cutaneous leishmaniasis and can be added to the literature.

Review of the Clinical Presentation, Pathology, Diagnosis, and Treatment of Leishmaniasis

Leishmaniasis is a vector-borne infection caused by kinetoplastid protozoans in the genera Leishmania and Endotrypanum. The disease occurs worldwide in the tropics and subtropics and can be particularly burdensome in resource-limited settings. Diseases caused by leishmaniasis range in severity from mild cutaneous lesions to life-threatening visceral and disfiguring mucocutaneous illnesses. Rapid and accurate diagnosis is needed to ensure proper clinical management of patients afflicted with this disease. Complicating matters of diagnosis and treatment are the diversity of species within these 2 genera and the variable specificity of diagnostic assays. This mini-review provides laboratory professionals with an overview of Leishmania epidemiology, biology, pathogenesis, clinical presentations, and treatments with additional emphasis placed on the nuances involved in diagnosis.

An Overview on Leishmaniasis in Romania: Diagnosis and Therapeutics

Leishmaniasis, a vector-borne disease considered to be one of the twenty neglected diseases by the World Health Organization, represents one of the public health concerns in endemic countries. In humans, as well as in animal counterparts, the infection can evolve with different clinical localizations, such as those that are cutaneous, mucocutaneous and visceral. Romania has been traditionally considered a nonendemic country for Leishmania species infection and has had sporadic positive human cases; however, the climate change recorded in recent decades has created potentially optimal conditions for the preponderant vectors of Phlebotomus spp., which has lately been identified in various parts of country. Moreover, with people and dogs (the prevailing hosts) traveling in endemic countries, the disease was imported and diagnosed in both species, and became a medical concern. In this review, we focused on the: (1) epidemiological data of leishmaniasis cases, both in humans and animals, reported by Romania; (2) diagnostic tools available for confirmation since there is a lack of gold-standard laboratory methods for human and dog patients; and (3) conventional antileishmanial therapy.

Anti-mitochondrial Tryparedoxin Peroxidase Monoclonal Antibody-Based Immunohistochemistry for Diagnosis of Cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL) remains a globally spreading public health problem. Among Latin America countries, Brazil has the greatest number of recorded CL cases with several Leishmania species being associated with human cases. Laboratory diagnosis is one of the major challenges to disease control due to the low accuracy of parasitological techniques, the restricted use of molecular techniques, and the importance of differential diagnosis with regard to several dermatological and systemic diseases. In response, we have developed and validated an immunohistochemistry (IHC) technique for CL diagnosis using anti-mTXNPx monoclonal antibody (mAb). Recombinant Leishmania–mTXNPx was produced and used as an immunogen for mAb production through the somatic hybridization technique. The viability of mAb labeling of Leishmania amastigotes was tested by IHC performed with skin biopsies from hamsters experimentally infected with Leishmania amazonensis, Leishmania braziliensis, and Leishmania guyanensis. The enzymes horseradish peroxidase (IHC-HRP) and alkaline phosphatase (IHC-AP), both biotin-free polymer detection systems, were used in the standardization step. The IHC was further validated with skin biopsies from 49 CL patients diagnosed by clinical examination and quantitative real-time polymerase chain reaction and from 37 patients presenting other dermatological infectious diseases. Other parasitological techniques, such as direct examination and culture, were also performed for confirmed CL patients. Histopathology and IHC were performed for all included patients. Overall, the highest sensitivity was observed for IHC-AP (85.7%), followed by IHC-HRP (79.6%), direct examination (77.6%), histopathological examination (HE; 65.3%), and in vitro culture (49%). Only IHC and HE presented specificity over 90% and were able to detect CL patients regardless of parasite burden (odds ratio > 1.94; 95%CI: 0.34–11.23). A significant increase in positivity rates was observed when IHC-AP was combined with direct examination (95.9%) and HE (93.9%). The IHC techniques evaluated in here detected the main Leishmania species causing CL in Brazil and can support diagnostic strategies for controlling this neglected disease, especially if used in combination with other approaches for an integrative laboratorial diagnosis.

Membrane Technology for Rapid Point-of-Care Diagnostics for Parasitic Neglected Tropical Diseases

Parasitic neglected tropical diseases (NTDs) affect over one billion people worldwide, with individuals from communities in low-socioeconomic areas being most at risk and suffering the most. Disease management programs are hindered by the lack of infrastructure and resources for clinical sample collection, storage, and transport and a dearth of sensitive diagnostic methods that are inexpensive as well as accurate. Many diagnostic tests and tools have been developed for the parasitic NTDs, but the collection and storage of clinical samples for molecular and immunological diagnosis can be expensive due to storage, transport, and reagent costs, making these procedures untenable in most areas of endemicity. The application of membrane technology, which involves the use of specific membranes for either sample collection and storage or diagnostic procedures, can streamline this process, allowing for long-term sample storage at room temperature. Membrane technology can be used in serology-based diagnostic assays and for nucleic acid purification prior to molecular analysis. This facilitates the development of relatively simple and rapid procedures, although some of these methods, mainly due to costs, lack accessibility in low-socioeconomic regions of endemicity. New immunological procedures and nucleic acid storage, purification, and diagnostics protocols that are simple, rapid, accurate, and cost-effective must be developed as countries progress control efforts toward the elimination of the parasitic NTDs.

The Geographical Distribution of Human Cutaneous and Visceral Leishmania Species Identified by Molecular Methods in Iran: A Systematic Review With Meta-Analysis

Leishmaniasis is one of the most common vector-borne parasitic diseases in Iran. Leishmania species identification is necessary for epidemiological aspects, precise prognosis, control and treatment of the disease. We systematically searched all the studies, reports, and documentation related to species identification and geographical distribution of causative agents of cutaneous (CL), mucosal (ML), and visceral leishmaniasis (VL) using DNA-based molecular diagnostic techniques in Iran. International databases including PubMed, ScienceDirect, Embase, Google Scholar, Scopus, and Web of Science were systemically searched for English articles and Iran's databases including SID, IranMedex and Magiran were searched for Persian reports and articles. Searches were performed from 1999 to 2019 (20 years). The current review was conducted using the keywords: cutaneous leishmaniasis, visceral leishmaniasis, Leishmania species, Human, Molecular, PCR, and Iran. The study quality was evaluated using the NOS checklist. This meta-analysis procedure was accomplished using STATA, version 2.7.9. Of the 3,426 records identified in the initial search, 154 articles met inclusion criteria and qualified for the systematic review and meta-analysis. In subgroup analysis, the pooled frequency of causative agents of CL isolates was 67.3% (95% CI: 59.51–74.67%) for L. major and 32.1% (95% CI: 24.72–39.87%) for L. tropica. In addition, the pooled frequency of causative agents of VL isolates was 97.1% (95% CI: 94.6–98.8%) for L. infantum and 2.9% (95% CI: 1.12–5.37%) for L. tropica. The findings of this study showed that the main causative agents of CL and VL in Iran are L. major and L. infantum, respectively. Moreover, kinetoplast DNA (kDNA) and internal transcriber spacer (ITS) were the most used markers for identifying Leishmania species. The current study provides valuable data to encourage and direct researchers as well as public health managers in the comprehensive leishmaniasis control and prevention planning in Iran.

Potential antigenic targets used in immunological tests for diagnosis of tegumentary leishmaniasis: A systematic review

Immunological tests may represent valuable tools for the diagnosis of human tegumentary leishmaniasis (TL) due to their simple execution, less invasive nature and potential use as a point-of-care test. Indeed, several antigenic targets have been used with the aim of improving the restricted scenario for TL-diagnosis. We performed a worldwide systematic review to identify antigenic targets that have been evaluated for the main clinical forms of TL, such as cutaneous (CL) and mucosal (ML) leishmaniasis. Included were original studies evaluating the sensitivity and specificity of immunological tests for human-TL, CL and/or ML diagnosis using purified or recombinant proteins, synthetic peptides or polyclonal or monoclonal antibodies to detect Leishmania-specific antibodies or antigens. The review methodology followed PRISMA guidelines and all selected studies were evaluated in accordance with QUADAS-2. Thirty-eight original studies from four databases fulfilled the selection criteria. A total of 79 antigens were evaluated for the detection of antibodies as a diagnostic for TL, CL and/or ML by ELISA. Furthermore, three antibodies were evaluated for the detection of antigen by immunochromatographic test (ICT) and immunohistochemistry (IHC) for CL-diagnosis. Several antigenic targets showed 100% of sensitivity and specificity, suggesting potential use for TL-diagnosis in its different clinical manifestations. However, a high number of proof-of-concept studies reinforce the need for further analysis aimed at verifying true diagnostic accuracy in clinical practice.

Immunotherapy in treatment of leishmaniasis

Leishmaniasis caused by various species of protozoan transmitted by sand fly vectors occurs as a spectrum of clinical features including cutaneous, mucocutaneous and visceral forms. It is a geographically distributed parasitic disease and a major public health problem in the world. The clinical syndromes are highly variable depending on the parasite species, host genetics, vectors and environment. To date, there is no effective vaccine and traditional treatments are toxic, expensive with long administration duration and many adverse side effects and/or drug resistance. Instead of treatments based on chemotherapy, certain strategies aim to recover leishmaniasis and reduce the parasitic burden. Immunotherapy has focused on the induction of effective immune response to rapidly control the disease. Recent studies have indicated that a single dose of a suitable therapeutic vaccine induces a quick and lasting recovery in patients. Immunotherapy reduces the toxicity of drug and the emergence of resistance dramatically. It could be an effective addition to chemotherapy with a safe and potent drug compared with monotherapy, resulting in a prophylactic and therapeutic cure of leishmaniasis. This review has focused on treatment of leishmaniasis with particular emphasis on immunotherapy as an alternative to conventional drug treatment.

Synthesis, Antileishmanial Activity and in silico Studies of Aminoguanidine Hydrazones (AGH) and Thiosemicarbazones (TSC) Against Leishmania chagasi Amastigotes

BACKGROUND

Leishmaniasis is a worldwide health problem, highly endemic in developing countries. Among the four main clinical forms of the disease, visceral leishmaniasis is the most severe, fatal in 95% of cases. The undesired side-effects from first-line chemotherapy and the reported drug resistance search for effective drugs that can replace or supplement those currently used an urgent need. Aminoguanidine hydrazones (AGH's) have been explored for exhibiting a diverse spectrum of biological activities, in particular the antileishmanial activity of MGBG. The bioisosteres thiosemicarbazones (TSC's) offer a similar biological activity diversity, including antiprotozoal effects against Leishmania species and Trypanosoma cruzi.

OBJECTIVE

Considering the impact of leishmaniasis worldwide, this work aimed to design, synthesize, and perform a screening upon L. chagasi amastigotes and for the cytotoxicity of the small "in-house" library of both AGH and TSC derivatives and their structurally-related compounds.

METHOD

A set of AGH's (3-7), TSC's (9, 10), and semicarbazones (11) were initially synthesized. Subsequently, different semi-constrained analogs were designed and also prepared, including thiazolidines (12), dihydrothiazines (13), imidazolines (15), pyrimidines (16, 18) azines (19, 20), and benzotriazepinones (23-25). All intermediates and target compounds were obtained with satisfactory yields and exhibited spectral data consistent with their structures. All final compounds were evaluated against L. chagasi amastigotes and J774.A1 cell line. Molecular docking was performed towards trypanothione reductase using GOLD® software.

RESULT

The AGH's 3i, 4a, and 5d, and the TSC's 9i, 9k, and 9o were selected as valuable hits. These compounds presented antileishmanial activity compared with pentamidine, showing IC50 values ranged from 0.6 to 7.27 μM, maximal effects up to 55.3%, and satisfactory SI values (ranged from 11 to 87). On the other hand, most of the resulting semi-constrained analogs were found cytotoxic or presented reduced antileishmanial activity. In general, TSC class is more promising than its isosteric AGH analogs, and the beneficial aromatic substituent effects are not similar in both series. In silico studies have suggested that these hits are capable of inhibiting the trypanothione reductase from the amastigote forms.

CONCLUSION

The promising antileishmanial activity of three AGH's and three TSC's was characterized. These compounds presented antileishmanial activity compared with PTD, showing IC50 values ranged from 0.6 to 7.27 μM, and satisfactory SI values. Further pharmacological assays involving other Leishmania strains are under progress, which will help to choose the best hits for in vivo experiments.

The Investigation of the Association of Cutaneous Leishmaniasis in Biopsy Specimens of the Patients with Granulomatous Disease and Skin Cancer Using the Molecular Method

Background

Clinically, cutaneous leishmaniasis (CL) can be confused with granulomatous diseases and skin cancers, and it may lead to erroneous diagnosis and treatment. Diagnosis based and histopathology can have some difficulties due to low number of parasites, especially in chronic CL cases. We aimed to emphasize the necessity of considering CL in the differential diagnosis for cases of granulomatous diseases and basal cell carcinoma, particularly in areas where CL is endemic.

Methods

One hundred and seven paraffin-embedded tissue biopsy specimens were selected from the archive, as of 2002, of Pathology Department, School of Medicine, University of Hatay Mustafa Kemal in Hatay, Turkey. After DNA isolation, performed with the samples were used for PCR analysis with specific 13A, 13B primers targeting kinetoplastid DNA (kDNA) found in all Leishmania species. Another PCR was performed with LITSR and L5.8S primers targeting ITS-1 internal-transcribed-spacer-1 (ITS-1) region to subtype positive samples. Then these samples were further analyzed for subtyping with PCR-RFLP using HaeIII enzyme (BsuRI).

Results

Ten out of 107 tissue specimens were positive via kDNA-PCR. Lupus vulgaris, sarcoidosis, skin lymphoma and Leishmania cutis appeared in 9 out of 10 positive specimens. One of the cases presented with a mass on the cheek and was pre-diagnosed with hemangioma, but leishmaniasis did not appear. All of 10 specimens were diagnosed as granulomatous dermatitis. Two out of 10 samples, found positive with kDNA-PCR, were analyzed with ITS-1-PCR and identified as L. infantum/donovani after RFLP.

Conclusion

Molecular methods should be utilized in the differential diagnosis of CL to eliminate false diagnoses of granulomatous diseases and skin cancers.

Cutaneous leishmaniasis: A pathological study of 360 cases with special emphasis on the contribution of immunohistochemistry and polymerase chain reaction to diagnosis

BACKGROUND

Traditional methods for the diagnosis of leishmaniasis yield poor sensitivity, which limits its effectiveness in lesions with a low parasite burden.

METHODS

Retrospective pathologic study of 360 cases of cutaneous leishmaniasis and analysis of the different diagnostic methods used.

RESULTS

In 93% of the lesions, histopathology showed a dense and diffuse inflammatory infiltrate, consisting of lymphocytes, histiocytes and plasma cells, which occupied the superficial and mid dermis and variably extended to deep dermis and superficial subcutis (standard pattern). The remaining cases exhibited atypical features, such as perivascular, interstitial or perifollicular inflammatory patterns, folliculitis or panniculitis. Granulomas were identified in 84% of biopsies, most of them as small, poorly formed, non-necrotizing histiocytic aggregates. Amastigotes were visualized by routine histopathologic exam in 36% of biopsies. Immunohistochemistry stained 17 of 26 lesions (65%) negative by conventional stains. PCR provided the correct diagnosis in 218 cases (58% of the series) negative for Leishmania by other techniques.

CONCLUSIONS

Biopsies negative for Leishmania by traditional diagnostic methods that show the histopathologic standard pattern, those with atypical features from patients with clinical suspicion of cutaneous leishmaniasis in endemic areas, should be studied by immunohistochemistry and/or PCR for Leishmania in order to reach the definitive diagnosis.

Leishmaniasis diagnosis: an update on the use of parasitological, immunological and molecular methods

Diagnosis of leishmaniasis has always been a major challenge as its clinical features resemble some other commonly occurring diseases such as tuberculosis, typhoid, and malaria. Reliable laboratory methods become important for differential diagnosis. Demonstration of the parasites in stained preparations of bone marrow and splenic aspirates being risky and invasive is still the gold standard for diagnosis. Serological tests utilizing rapid immunochromatographic formats or rK39 in enzyme linked immune sorbent assay, immunoblotting, direct agglutination test have complications related to high proportions of positive asymptomatic individuals and the inability to diagnose a relapse. Among the molecular techniques, polymerase chain reaction is the most commonly used technique that is successfully implied for diagnosis. This review provides updated information on the recent developments in the field of diagnosis in leishmaniasis, various methods utilized with their advantages and limitations.

Lipophilic tracer Dil and fluorescence labeling of acridine orange used for Leishmania major tracing in the fibroblast cells

Background

This study aims to evaluate the use of fluorescent dye Dil and super vital dye acridine orange (AO) in vitro tracking of labeled L. major in the fibroblast cells.

Methods

Dil crystal and AO were used to stain L. major in a co-culture of the fibroblasts with the parasite. AO staining solution was added to 1 × 10⁶ parasites. After 10 min, the stained parasites were centrifuged and washed seven times with phosphate buffered saline (PBS). The stained promastigote was incubated with fibroblasts for 6-8 h. The presence of stained parasites with AO in the fibroblast was assessed using a fluorescence microscope. 1 × 10⁶/mL promastigote of L. major was gently suspended and mixed by Dil staining solution with an ultimate concentration of 0.002 μg/mL and it was kept for 20 min at the room temperature. Subsequently, after washing it in PBS for seven times, it was centrifuged at 3000 rpm for 10 min. The supernatant was removed and the precipitate containing stained promastigote was suspended in fresh DMEM F12 with fibroblasts at 37 °C for 6 h. The presence of stained parasites with Dil in fibroblast was assessed using a fluorescence microscope. Fibroblast characterization was undertaken by a real-time polymerase chain reaction (PCR).

Results

Acridine orange staining assisted in detection of the live parasite in the fibroblast cells. Free promastigote looked green before entering into the fibroblasts after 12 h culture. The parasite entered the cytoplasm of fibroblasts at the beginning of the exposure and gradually entered the nucleus of the fibroblast. The fibroblast nucleus was entirely stained green by AO. The L. major appeared green under the fluorescent microscope. Dil staining revealed that the internalized parasites with red/orange color were localized within the cytoplasm after 6-hours and the nucleus of the fibroblasts after 72-hours following culture. Human fibroblasts were positive at the expression of CD10, CD26, matrix metalloproteinase-1 (MMP-1) and matrix metalloproteinase-3 (MMP-3) and negative for CD106 and integrin alpha 11.

Conclusion

The fluorescent dye Dil staining is a safe, easy to use, inexpensive and fast method for labeling of the Leishmania parasite in the fibroblast cells. Acridine orange staining could be useful for tracing the parasites in the fibroblasts too. In this study, both Dil and AO were compared and considered as suitable vital dyes for identifying labeled Leishmania in the fibroblast in vitro, but Dil was superior to AO with its feature does not transfer from the labeled to unlabeled cells.

Ability of real-time PCR for differential diagnosis of various forms of cutaneous leishmaniasis: a comparative study with histopathology

Objective

Histopathological studies suggest that parasite load is different between acute and chronic forms of cutaneous leishmaniasis (CL). However, highly sensitive detection methods are still needed to distinguish different forms of leishmaniasis. In the present study, we developed a quantitative real-time polymerase chain reaction (PCR) to detect and quantify Leishmania tropica parasites in paraffin-embedded tissue samples.

Results

The ability of real-time PCR for leishmania detection was higher than histopathological evaluation. The quantitative real-time PCR (qPCR) quantified parasite loads were highly correlated with microscopic results (r = 0.598; P < 0.001). Among patients, the parasite load was inversely correlated with disease duration (acute CL lesions had very higher parasite load than chronic CL lesions), but there was no difference in the parasite load according to the patients’ age and sex as well as location of the lesions. In contrast to Ridley scoring system (P < 0.001), there were no statistically significant differences in the relative number of parasites among the lupoid and non-lupoid forms of chronic lesions in real-time PCR (P = 0.549), which indicates the superiority of histopathological evaluation for chronic forms differentiation.

Case Report: Squamous Cell Carcinoma Referred for Mohs Surgery Found to be Cutaneous Leishmaniasis

Chronic skin lesions constitute a clinical diagnostic challenge. We report the case of a patient whose facial lesion was histopathologically compatible with squamous cell carcinoma and hence programmed for Mohs surgery. However, review of the clinical and epidemiological history led to laboratory diagnosis of cutaneous leishmaniasis, treatment with miltefosine, and complete resolution of the lesion.

Effectiveness of amiodarone in treatment of cutaneous leishmaniasis caused by Leishmania major

Development of new chemotherapeutic agents is an essential issue in the treatment and control of a disease. This study aimed to evaluate the anti-leishmanial activity of amiodarone, an antiarrhythmic class III drug, against Leishmania major, the most prevalent etiological agent of cutaneous leishmaniasis in the old world. The proliferation of promastigotes and intracellular amastigotes in the absence or presence of amiodarone was estimated, in an in vitro study. For in vivo study, five weeks after infection of BALB/c mice with L. major, when the lesions appeared at the injection site, the mice were divided into four groups (n = 6 each); treatment was conducted for 28 consecutive days with vehicle, amiodarone at 40 mg/kg orally and glucantime at 60 mg/kg intraperitoneally. Therapy with amiodarone reduced the size of lesions compared to the untreated group after 12 days. Amiodarone decreased the parasite load and inflammatory responses, particularly the macrophages containing amastigotes, and enhanced granulation tissue formation in the dermis and subcutaneous area. The Tumor necrosis factor-α and Interleukin-6 levels were significantly lower in the cell culture supernatants of the inguinal lymph node in the amiodarone treated group compared to the vehicle and untreated groups. Amiodarone significantly increased the activity of glutathione peroxidase in comparison to the vehicle and untreated groups but did not affect the plasma levels of superoxide dismutase, malondialdehyde, adiponectin, and ferric reducing ability of plasma. Therefore, the anti- L. major activity and immunomodulatory effects of amiodarone reduced the parasitic load and enhanced wound healing in cutaneous leishmaniasis in BALB/c mice. Amiodarone reduced the lesion surface area, but it did not cure it completely.

Leishmania donovani Induced Cutaneous Leishmaniasis: An Insight into Atypical Clinical Variants in Sri Lanka

Sri Lanka is a recent focus having Leishmania donovani induced cutaneous leishmaniasis (CL) as the main clinical entity. A separate clinical entity within profile of CL was described in this study. Laboratory confirmed cases of CL (n= 950, 2002-2014) were analysed. Most lesions showed known classical developmental stages of CL (CCL) observed in other CL endemic settings while few cases (13%, 122/950) showed atypical skin manifestations (ACL). Clinical, geographical, and treatment response patterns of ACL were different from those of CCL. ACL was mainly found among males (68.0%), in 21-40 year age group (51.6%), and reported delayed treatment seeking (23.5% vs 16.3% in CCL), more nonclassical onset (lesions other than acne form <1cm sized papules), (12.1 vs 2.7%, P<0.05.), more head and neck lesions (41.5%. vs 27.2%), more large lesions (>4cm), (18.6 vs 9.9%), and poor laboratory positivity rates (65.6% vs 88.2%) when compared to CCL. When compared to lesions reporting a typical onset, lesions reporting nonclassical onset were more likely to develop ACL later on (50.1% vs 10.7%). As compared to lesions on limbs, those on head and neck and trunk were more likely to be ACL (7.0%, 16.3%, and 22.8%, respectively, P<0.05). ACL features were not age or gender dependent. Highest proportion within ACL category (32.8%) and small proportion of CCL (10.1%) originated from less leishmaniasis prevalent areas (other regions) (P<0.05). North reported more ACL than South (15.9% vs 7.4%). A total of 95 CL cases with a significant travel history were further analyzed. Residents of other regions when acquired infection from North or South developed more ACL than residents in North or South (60.9% vs 15.9% and 42.9% vs 7.4% respectively). Patients in other regions when travelled to North developed more ACL than when they travelled to South (60.9%, 42.9%). ACL and CCL required an average of 18 doses over 16.7 months and 10 doses over 12 weeks, respectively, to achieve a complete clinical cure. Underlying host immunological factors, parasite strain variations and regional variations of both could be underlying etiologies. Established independent transmission within less leishmaniasis prevalent regions combined with an unusual clinical picture leading to poor clinical suspicion and low laboratory confirmation rate will pose potential difficulties in early case detection in these highly populated and commercialized areas. This in turn will further facilitate silent and high disease transmission.

Intraspecies susceptibility of Leishmania (Viannia) braziliensis to antileishmanial drugs: Antimony resistance in human isolates from atypical lesions

Leishmania (Viannia) braziliensis is the most common etiological agent of cutaneous and mucocutaneous leishmaniasis (MCL) in Latin America. An interesting aspect of the disease outcome caused by this species is the appearance of non-ulcerated atypical cutaneous leishmaniasis. Atypical (AT) lesions are often associated with therapeutic failure when treated with antimony(Sb)-based drugs. Refractory cases are not necessarily due to intrinsic parasite drug resistance. The status of in vitro drug susceptibility from L. braziliensis field isolates is less assessed than patient treatment outcome. In this work, L. braziliensis isolated from typical CL (6), MCL (1) and AT (3) lesions and vector (1) were tested for their susceptibility to amphotericin B (AmB), miltefosine (MIL), glucantime (GLU) and non-comercial meglumine antimoniate (MA). Overall, intracellular amastigotes of all isolates were sensitive to the tested antileishmanial drugs except AT lesions-derived strains 316, 330 and 340 that presented in vitro resistance against Sb^V-based drugs. Although susceptible to miltefosine - based on phenotypic screening - intramacrophagic quiescent amastigotes could restore infection. L. braziliensis promastigotes isolated from AT lesions also displayed 29% reduced capacity to infect human monocyte-derived macrophages when compared with parasites obtained from patients with typical lesions, MCL or from sand-fly. These data indicate differences in drug susceptibility and infectiveness among L. braziliensis isolated from patients exhibiting different types of lesions and highlight the importance of its characterization for drug response prediction outcome in clinical practice.

Emerging role of amiodarone and dronedarone, as antiarrhythmic drugs, in treatment of leishmaniasis

Leishmaniasis is a group of human and animal diseases causing 20,000-40,000 annual deaths and its etiological agents belong to the Leishmania genus. The most current treatment against leishmaniasis is chemotherapy. Pentavalent antimonials such as glucantime and pentostam have been administrated as the first-line drugs in treatment of various forms of leishmaniasis. The second-line drugs such as amphotericin B, liposomal amphotericin B, miltefosine, pentamidine, azole drugs and paromomycin are used in resistant cases to pentavalent antimonials. Because of drawbacks of the first-line and second-line drugs including adverse side effects on different organs, increasing resistance, high cost, need to hospitalization and long-term treatment, it is necessary to find an alternative drug for leishmaniasis treatment. Several investigations have reported the effectiveness of amiodarone, the most commonly used antiarrhythmic drug, against fungi, Trypanosomes and Leishmania spp. in vitro, in vivo and clinical conditions. Moreover, the beneficial effects of dronedarone, amiodarone analogues, against Trypanosoma cruzi and Leishmania mexicana have recently been demonstrated and such treatment regimens resulted in lower side effects. The anti- leishmanial and anti- trypanosomal effectiveness of amiodarone and dronedarone has been attributed to destabilization of intracellular Ca²⁺ homeostasis, inhibition of sterol biosynthesis and collapse of mitochondrial membrane potential. Because of relative low cost, excellent pharmacokinetic properties, easy accessibility and beneficial effects of amiodarone and dronedarone on leishmaniasis, they are proper candidates to replace the current drugs used in leishmaniasis treatment.

Accuracy of a Rapid Diagnostic Test Based on Antigen Detection for the Diagnosis of Cutaneous Leishmaniasis in Patients with Suggestive Skin Lesions in Morocco

In rural areas in Morocco, diagnosing cutaneous leishmaniasis (CL) can be challenging. We evaluated the accuracy of a rapid diagnostic test (RDT) based on antigen detection, CL Detect Rapid Test^™ (Inbios International Inc., Seattle, WA), in this setting. We consecutively recruited patients with new skin ulcers in nine primary health centers. We took a dental broach sample for the RDT and two other tissue samples by scraping the border and center of the lesion with a scalpel and smearing it on a slide. We duplicated each smear by pressing a clean slide against it and processed the slides by microscopy, polymerase chain reaction (PCR) internal transcribed spacer 1, and kDNA minicircle PCR. In a subgroup with positive PCR, the Leishmania species was identified using PCR-restriction fragment length polymorphism and PCR-sequencing of hsp70 genes. A participant with positive microscopy and/or PCR was considered a confirmed CL case. We computed sensitivity (Se) and specificity (Sp) of the RDT compared with this reference standard (ClinicalTrials.gov registration: NCT02979002). Between December 2016 and July 2017, we included 219 patients, 50% of them were under 18 years old. Rapid diagnostic test Se was 68% [95% confidence interval (CI): 61–74], Sp 94% [95% CI: 91–97], positive predictive value 95% [95% CI: 92–98], and negative predictive value 64% [95% CI: 58–70]. Despite its low Se, this novel RDT is a useful addition to clinical management of CL in Morocco, especially in isolated localities. Rapid diagnostic test–positive lesions can be treated as CL; but when RDT negative, microscopy should be done in a second step. The Se of the RDT can probably be optimized by improving the sampling procedure.

Prevalence of and Factors Associated with Negative Microscopic Diagnosis of Cutaneous Leishmaniasis in Rural Peru

Cutaneous leishmaniasis is endemic to South America where diagnosis is most commonly conducted via microscopy. Patients with suspected leishmaniasis were referred for enrollment by the Ministry of Health (MoH) in Lima, Iquitos, Puerto Maldonado, and several rural areas of Peru. A 43-question survey requesting age, gender, occupation, characterization of the lesion(s), history of leishmaniasis, and insect-deterrent behaviors was administered. Polymerase chain reaction (PCR) was conducted on lesion materials at the Naval Medical Research Unit No. 6 in Lima, and the results were compared with those obtained by the MoH using microscopy. Factors associated with negative microscopy and positive PCR results were identified using χ² test, t-test, and multivariate logistic regression analyses. Negative microscopy with positive PCR occurred in 31% (123/403) of the 403 cases. After adjusting for confounders, binary multivariate logistic regression analyses revealed that negative microscopy with positive PCR was associated with patients who were male (adjusted odds ration [OR] = 1.93 [1.06-3.53], P = 0.032), had previous leishmaniasis (adjusted OR = 2.93 [1.65-5.22], P < 0.0001), had larger lesions (adjusted OR = 1.02 [1.003-1.03], P = 0.016), and/or had a longer duration between lesion appearance and PCR testing (adjusted OR = 1.12 [1.02-1.22], P = 0.017). Future research should focus on further exploration of these underlying variables, discovery of other factors that may be associated with negative microscopy diagnosis, and the development and implementation of improved testing in endemic regions.

Clinical and epidemiological characteristics of cutaneous leishmaniasis in Sri Lanka

Background

Leishmaniasis, a vector borne tropical/subtropical disease caused by the protozoan Leishmania is transmitted to humans by sandfly vectors Phlebotomus and Lutzomyia. The principal form found in Sri Lanka is cutaneous leishmaniasis (CL) and is caused by Leishmania donovani. A rising trend in disease prevalence has been observed recently in Sri Lanka and the island is in fact the newest endemic focus in South Asia. Determining the prevalence of smear positivity among clinically suspected CL patients, identifying risk factors and specific clinical presentations of CL in order to implement preventive and early treatment strategies were the objectives of this study.

Methods

A sample of 509 clinically suspected cases of CL referred to the Department of Parasitology from all across Sri Lanka between 2005 and 2015 was selected consecutively. Diagnosis was confirmed by microscopic visualization of the Leishmania amastigote from the slit skin smear. A structured questionnaire was used to identify exposure related risk factors and a clinical examination was performed to identify lesion characteristics.

Results

Out of 509 clinical cases, 41.5% (n = 211) were smear positive. The study population ranged from ages 1 to 80 years (mean age = 34.76) and the most affected age group was 40–49. Of the smear positives, 58.85% were males. Majority (47.86%) were from the North Western region (Kurunegala) of the country and were exposed to scrub jungles. Sand fly exposure (p = 0.04) and positive contact history (p = 0.005) were significant risk factors for smear positivity.

Erythema (p = 0.02), lack of pruritus (p = 0.02) and scaly appearance (p = 0.003) were significant lesion characteristics in smear positivity. Lesions were commonly found in the exposed areas and the commonest morphological type was papulo-nodular.

Conclusions

An increasing trend in the spread of cutaneous leishmaniasis from endemic to non-endemic areas has become evident. Positive contact history and sandfly exposure were significant risk factors for smear positivity which may indicate the possibility of human reservoir hosts in infection transmission. Lack of pruritus, scaly appearance and erythema were highly significant lesion characteristics associated with Leishmania positive smears which can be used for the clinical diagnosis of CL.

Application of nanotechnology in treatment of leishmaniasis: A Review

Leishmaniasis is a neglected tropical disease caused by a protozoan species of the genus Leishmania affecting mostly the developing countries. The disease with current mortality rate of 50,000 deaths per year threatens approximately 350 million people in more than 90 countries all over the world. Cutaneous, mucocutaneous and visceral leishmaniasis are the most frequent forms of the disease. Chemotherapy still relies on the use of pentavalent antimonials, amphotericin B, liposomal amphotericin B and miltefosin. Treatment of leishmaniasis has remained insufficient since the current antileishmanial agents have several limitations including low efficacy, toxicity, adverse side effects, drug-resistance, length of treatment and cost lines. Consequently, there is an immediate requirement to search for new antileishmanial compounds. New drug delivery devices transport antileishmanial drug to the target cell specifically with minimizing the toxic effects to normal cells. This study attempts to present a comprehensive overview of different approaches of nanotechnology in treatment of leishmaniasis.

Characterization of the Histopathologic Features in Patients in the Early and Late Phases of Cutaneous Leishmaniasis

Cutaneous leishmaniasis (CL), characterized by an ulcerated lesion, is the most common clinical form of human leishmaniasis. Before the ulcer develops, patients infected with Leishmania (Viannia) braziliensis present a small papule at the site of the sandfly bite, referred to as early cutaneous leishmaniasis (E-CL). Two to four weeks later the typical ulcer develops, which is considered here as late CL (L-CL). Although there is a great deal known about T-cell responses in patients with L-CL, there is little information about the in situ inflammatory response in E-CL. Histological sections of skin biopsies from 15 E-CL and 28 L-CL patients were stained by hematoxilin and eosin to measure the area infiltrated by cells, as well as tissue necrosis. Leishmania braziliensis amastigotes, CD4⁺, CD8⁺, CD20⁺, and CD68⁺ cells were identified and quantified by immunohistochemistry. The number of amastigotes in E-CL was higher than in L-CL, and the inflammation area was larger in classical ulcers than in E-CL. There was no relationship between the number of parasites and magnitude of the inflammation area, or with the lesion size. However, there was a direct correlation between the number of macrophages and the lesion size in E-CL, and between the number of macrophages and necrotic area throughout the course of the disease. These positive correlations suggest that macrophages are directly involved in the pathology of L. braziliensis-induced lesions.

Worldwide risk factors in leishmaniasis

Recently, vector-borne parasitic diseases such as leishmaniasis have been emerged or re-emerged in many geographical areas and resulted in global health and economic concerns that involve humans, domestic animals and wild life. The ecology and epidemiology of leishmaniasis are affected by the between host, reservoir and vector (human, animal and sandfly) and the environment. Important drivers for the emergence and spread of leishmaniasis include environmental factors such as alterations in temperature and water storage, irrigation habits, deforestation, climate changes, immunosuppression by HIV or organ transplant, development of drug resistance, increase traveling to endemic regions and dog importation. War, poor socio-economic status and low level household are also major contributors to the spread of this disease. Health education via the public media and training should be implemented by international organizations and governmental agencies in collaboration with research institutions. Fully protection during transmission season, using bednets and insecticides and reservoirs' control should be also mentioned in the planning. Based on the findings of the recent studies and high prevalence of leishmaniasis, it is concluded that serious public health monitoring should be considered.

Control of Cutaneous Leishmaniasis Using Geographic Information Systems from 2010 to 2014 in Khuzestan Province, Iran

Background

Cutaneous leishmanisis (CL) is found worldwide and is considered to be endemic in 88 countries such as Iran. Geographic information system (GIS) is a method that can create, archive, analyze traditional map and place data of the disease distribution. The aim of this study was to produce distributional maps of CL over five years and evaluate the role of GIS in control of CL in Khuzestan province where an endemic area of CL in Iran is.

Methods

CL epidemiological data on the District and village levels for the period 2010–2013 were provided as census by health surveillance system in all counties and in control diseases center (CDC) of Khuzestan province. After collection of CL data, the collected data of CL from 2010 to 2013 were analyzed using GIS. The collected data of CL from 2010 to 2013 was analyzed using GIS. The endemic areas of CL during 2010–2013 were recognized using GIS maps and the control programs of CL were done in these regions based on epidemiological situation and the stratification of risk areas.

Results

During the study period, there were 4672 recorded cases of clinical cases of CL by Khuzestan Health Center. Data of GIS referring to CL patients showed that center and eastern districts of Khuzestan had a significant number of cases. In 2014 that control program was done, ten distinct of Khuzestan Province didn’t show any cases of the disease.

Conclusion

In conclusion, analyses of data distributed in the geographic spaces are increasingly appreciated in leishmaniasis control management. GIS tools promoted greater efficiency in making decisions and planning activities in the control of vector born disease such as leishmaniasis.

Correlation of Genetic Heterogeneity with Cytopathological and Epidemiological Findings of Leishmania major Isolated from Cutaneous Leishmaniasis in Southern Iran

OBJECTIVE

Cutaneous leishmaniasis (CL) has recently grown into a major public health problem in 88 countries of the world, including Iran. It is a polymorphic disease which may show various clinicopathological features. Although the effect of the genetic diversity of the parasite has been demonstrated as one of the factors influencing clinical manifestations in CL, no data exist regarding the genetic variation of Leishmania major and its microscopical features.

STUDY DESIGN

Fine-needle aspiration, touch smears and the histological sections of 100 patients were examined for Leishmania amastigotes, using Giemsa and hematoxylin and eosin. Diverse types of inflammatory cells in the 40 positive and 5 negative smears were differentiated. Kinetoplast DNA (kDNA) was amplified using nested PCR and subsequently sequenced. Sequencing analysis of the amplified kDNA was used to investigate the genetic variations among L. major isolates and to correlate the findings with microscopical features and geographical origins.

RESULTS

The quantified amastigote density in the 40 positive touch smears was blindly classified by 3 observers. Grade I, II, III and IV had 7, 13, 9 and 11 cases, respectively. The microscopical features, the mean percentage of neutrophils, lymphocytes and other inflammatory cells, and the leishmanial density of the grades and negative cytopathological samples were contrasting. kDNA amplification of L. major was detected from the cutaneous lesion, and 21 of these amplicons were successfully sequenced.

CONCLUSIONS

These results indicate that L. major strains causing CL in southern Iran are genetically diverse; furthermore, a correlation between the genetic heterogeneity of the parasite, the microscopical manifestation and the geographical regions of the disease in humans was found.

Evaluation of Live Recombinant Nonpathogenic Leishmania tarentolae Expressing Cysteine Proteinase and A2 Genes as a Candidate Vaccine against Experimental Canine Visceral Leishmaniasis

Canine Visceral Leishmaniasis (CVL) is a major veterinary and public health problem caused by Leishmania infantum (L. infantum) in many endemic countries. It is a severe chronic disease with generalized parasite spread to the reticuloendothelial system, such as spleen, liver and bone marrow and is often fatal when left untreated. Control of VL in dogs would dramatically decrease infection pressure of L. infantum for humans, since dogs are the main domestic reservoir. In the past decade, various subunits and DNA antigens have been identified as potential vaccine candidates in experimental animal models, but none has been approved for human use so far. In this study, we vaccinated outbreed dogs with a prime-boost regimen based on recombinant L. tarentolae expressing the L. donovani A2 antigen along with cysteine proteinase genes (CPA and CPB without its unusual C-terminal extension (CPB^-CTE) and evaluated its immunogenicity and protective immunity against L. infantum infectious challenge. We showed that vaccinated animals produced significantly higher levels of IgG2, but not IgG1, and also IFN-γ and TNF-α, but low IL-10 levels, before and after challenge as compared to control animals. Protection in dogs was also correlated with a strong DTH response and low parasite burden in the vaccinated group. Altogether, immunization with recombinant L. tarentolae A2-CPA-CPB^-CTE was proven to be immunogenic and induced partial protection in dogs, hence representing a promising live vaccine candidate against CVL.

Immunological comparison of DNA vaccination using two delivery systems against canine leishmaniasis

Visceral leishmaniasis (VL) is a fatal disease caused by the intracellular protozoan parasite Leishmania infantum. Dogs are the primary reservoirs of this parasite, and vaccination of dogs could be an effective method to reduce its transfer to humans. In order to develop a vaccine against VL (apart from the choice of immunogenic candidate antigens), it is necessary to use an appropriate delivery system to promote a proper antigen-specific immune response. In this study, we compared two vaccine delivery systems, namely electroporation and cationic solid-lipid nanoparticle (cSLN) formulation, to administer a DNA vaccine containing the Leishmania donovani A2 antigen, and L. infantum cysteine proteinases of type I (CPA) and II (CPB) without its unusual C-terminal extension. The protective potencies of these two vaccine delivery systems were evaluated against L. infantum challenge in outbred dogs. Our results show that the administration of pcDNA-A2-CPA-CPB(-CTE)GFP vaccine as a prime-boost by either electroporation or cSLN formulation protects the dogs against L. infantum infection. Partial protection in vaccinated dogs is associated with significantly (p<0.05) higher levels of IgG2, IFN-γ, and TNF-α and with low levels of IgG1 and IL-10 as compared to the control group. Protection was also correlated with a low parasite burden and a strong delayed-type hypersensitivity (DTH) response. This study demonstrates that both electroporation and cSLN formulation can be used as efficient vaccine delivery systems against visceral leishmaniasis.

Skin infections in returned travelers: an update

Dermatologic manifestations of travel-related illness are particularly vexing due to the broad differential diagnosis and clinicians' unfamiliarity with uncommonly seen diseases. This paper aims to educate and update the reader on selected infectious diseases in the returned traveler whose disease manifestations are primarily dermatologic. First, the evolving epidemiology of these infections is examined; understanding the geographic distribution of infectious etiologies helps refine and narrow the differential diagnosis. This is followed by a discussion of six important clinical syndromes including cutaneous larva migrans (CLM), cutaneous leishmaniasis, tungiasis, myiasis, antibiotic-resistant skin and soft tissue infection, and selected infections associated with fever and rash (e.g., measles, chikungunya virus infection, dengue fever, rickettsial spotted fevers). Familiarity with these syndromes and a situational awareness of their epidemiology will facilitate a prompt, accurate diagnosis and lead to appropriate treatment and prevention of further disease spread.

Cutaneous Leishmaniasis: Current Treatment Practices in the USA for Returning Travelers

Leishmaniasis, a protozoal infection transmitted by sandfly bite, produces a clinical spectrum of disease ranging from asymptomatic infection to ulcerative skin and mucosal lesions to visceral involvement. Leishmaniasis is endemic in regions of Africa, the Middle East, south Asia, southern Europe, northern South America, and Central America. There has been an increase in imported leishmaniasis into developed, non-endemic countries due to increasing global travel. While pentavalent antimonials have been the mainstay of antileishmanial treatment for decades, newer therapeutic options have become available for all forms of infection, including liposomal amphotericin B, miltefosine, fluconazole, and ketoconazole. For the returning traveler with cutaneous leishmaniasis in the USA, treatment approaches are determined based on infecting species, initial presentation, extent and progression of disease, the advantages and drawbacks of available parenteral and oral drugs, and clinician-consultant experience.

Improving Leishmania species identification in different types of samples from cutaneous lesions

The discrimination of Leishmania species from patient samples has epidemiological and clinical relevance. In this study, different gene target PCR-restriction fragment length polymorphism (RFLP) protocols were evaluated for their robustness as Leishmania species discriminators in 61 patients with cutaneous leishmaniasis. We modified the hsp70-PCR-RFLP protocol and found it to be the most reliable protocol for species identification.

The role of climate on prevalence or eradication of vesical schistosomiasis in Khuzestan Province of Iran

Climate is defined as the combination of climate and air elements of a given region which is usually measured for a period of decades. De-marton climate classification has been established based on many factors, including elements such as temperature and rainfall. Vesicle schistosomiasis is a parasitic disease caused by Schistosoma haematobium. This parasite lives in the blood vessels of the bladder. The parasite can cause hematuria in human and if not treated properly can lead to vesicale carcinoma. The parasite is distributed only in certain parts of the province and it is highly dispersed along the rivers of Dez, Karkheh and Karun with high emissions. In 1970, the prevalence of infection in infected foci was 23.8 %. Campaign against the parasite began in 1958 but it did not encompass all centers of infection. Preventive measures include diagnosis and treatment of patients, public health promotion, health education, drying swamps and ponds, improving the environment, cementing the irrigation canals, and the use of moluscocide eventually leads to changing the ecological and conditions of parasite and snail inhabits. Application of preventive measures resulted in the reduction of infection level to 0.7 % in 1979. By continuing struggle and intensifying preventive measures and changing ecological and climatic environment, in 2008, the examination of 3400 urine samples of students in Andimeshk district revealed no cases of the vesical schistosomiasis. It is concluded that S. haematobium and vesical schistosomiasis is eliminated from Khuzestan province southwest Iran, but the disease is still prevalent in neighboring Iran's western border country (Iraq) and due to the special conditions of its facilities and the traffic between the two countries, it is necessary to control and eradicate the disease in Iraq by using the experiences of Iran in eliminating the disease.