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Background & Objective: Visceral leishmaniasis (kala-azar) is an infectious-parasitic disease occurring sporadically in various parts of Iran. The disease is endemic in Ardabil, East Azarbaijan, Bushehr and Fars provinces. This study was performed with the aim of evaluation and comparison of direct agglutination test (DAT), indirect immunofluorescent antibody (IFAT) and ELISA in sero-diagnosis of visceral leishmaniasis that is following a seroepidemiological survey in Germi district of Ardabil province.
Methods: Cluster sampling has been performed from ≤12 years old and 10% of the adult population in Germi district. Altogether 1155 blood specimens were collected to detect anti- Leishmania antibodies. The samples were tested by direct agglutination test (DAT), indirect immunofluorescent antibody (IFAT) and ELISA methods.
Results: 32 (2.8%) of the collected specimens have anti-Leishmania antibodies with titers ≥1:800 and from total specimens 7 (0.6%) were positive with ≥1:3200 titers. In IFA test 32 (2.8%) have titers ≥1:40 and from total specimens 6 (0.52%) were positive with ≥1:320 titers. In ELISA test 8 specimens were positive and other specimens were negative.
Conclusions: According to the results of this study, IFAT and ELISA are specific and high sensitive tests for sero-diagnosis of visceral leishmaniasis but these methods are expensive and require the complicated tools. Whereas, DAT is a simple method, not expensive and require a simple local laboratory with one or two trained technicians. Therefore DAT could be used for seroepidemiological studies and sero-diagnosis of visceral leishmaniasis in endemic areas instead of IFA and ELISA methods.

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  Background & Objectives: Leishmania infantum is the causative agent of visceral leishmaniasis (VL). Based on isoenzyme typing of a few isolates from patients and domestic dogs, this parasite was considered to predominate in the Kaleybar focus of VL in northwest Iran. There is no report of sandfly infections in this region so this study was aimed to investigate the infection of the sandflies in the field.

  Methods: Sandflies were sampled using sticky paper and CDC traps. Morphological identifications were carried out based on characters of the head and abdominal terminalia. DNA extracted from sandflies abdomens and thoraxes. ITS-rDNA gene of parasite was detected and identified as Leishmania after sequencing.

  Results: Out of 146 sandflies 9 were found to be infected with Leishmania. For first time, three Leishmania species (L. infantum, L. tropica and L. major) were identified in sandflies simultaneously in the region. Among the all sandflies only one Phlebotomus perfiliewi (vector of VL) was found to be infected with L. infantum. All Isolates were confirmed by sequencing of ITS-rDNA gene.

  Conclusion: However, Leishmania tropica and L. major were found more than L. infantum in sandflies in Kaleybar but it could not conclude that these two species of Leishmania are causative agents of VL. Because many criteria should be considered to incriminate an agent or vector of the disease.

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  Background & Objectives : Visceral leishmaniasis is an important endemic disease in Iran and Meshkin shahr County is the most important foci of visceral leishmaniasis in Iran. The aim of this study is the survey of recent changes in epidemiological patterns of visceral leishmaniasis in Meshkin Shar area during 12 years.

  Methods : This is a descriptive retrospective study. Records of 193 cases with confirmed kala-azar disease were reviewed in the period of 2001-2012. Data collected from files and were analyzed using descriptive statistics and SPSS v.15.

  Results : From 193 patients with confirmed kala-azar disease, 85% were resident in rural and 15% in urban areas. Among of these patients, 43% were female and 57% male. About 66% of patients were under 2 years old, 23% in age group between 2-5 years and 11% above five years. Among four parts of Meshkin Shahr County, in the first five years of the study, the most cases of the disease were from the central part, but in second six years the most cases were from the west part of this county and in latest year (2012) it has been coverted .

  Conclusions : Incidence of kala-azar was decreased during last 12 years. Because of high infection rate in dogs and considering important role of these reservoirs in conserving and distribution of disease, stopped health activities in any parts of area can increase the incidence of disease.

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  Background & objectives: The leishmaniases are considered among the major infectious diseases affecting public health in several regions. There are many chemical agents which are effective in treatment of visceral leishmaniasis. But, overall treatment of visceral leishmaniasis is often difficult. Thus, identification of new chemotherapeutic agents is important for treatment of disease. Since targeting of the ergosterol synthesis pathway of Leishmania may be useful therapeutically, the aim of this study was to investigate the effect of alone or in combination of amiodarone and ketoconazole on Leishmania infantum.

  Methods : To obtain logarithmic promastigotes of L. infantum, the parasites were cultured in BHI medium with FCS 10% together with antibiotics of penicillin and streptomycin and incubated at 24° C. Amastigote forms were obtained in BHI medium supplemented with 20% FCS at pH of 5.5 which incubated in 37° C. L.infantum susceptibility to amiodarone and ketoconazole was evaluated by proliferation of parasites in the absence or presence of these drugs with MTT assay. For evaluation of antiproliferative synergism against promastigotes and axenic amastigotes, fractional inhibitory concentrations (FIC) were calculated. An isobologram curve was constructed too.

  Results: Amiodarone produced a marked reduction in the viability of L.infantum promastigotes and axenic amastigotes. On the other hand ketoconazole induced a dose dependent effect on the parasites proliferation for promastigotes and axenic amastigotes. When the drugs were used in combination, the results indicated clear synergistic as shown by a concave isobologram and FIC value.

  Conclusion: The present study represents the evidence that the combination of amiodarone plus ketoconazole acts synergistically in controlling L. infantume in vitro. It is possible that amiodarone could be used in combination with ketoconazole to combat infection at low doses, thus reducing its side effects such as cardiotoxicity, thyroid dysfunction and pulmonary fibrosis.

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Background & objectives: Visceral leishmaniasis is a zoonotic disease and is considered as the most important disease in dogs. The disease has been reported in North West and South of the country, in Iran. In addition to stray dogs, some apparently healthy dogs can be contaminated without showing any sign or symptoms in this area. In the present study, canine visceral leishmaniasis was investigated in dogs lacking clinical signs in Meshkinshahr city in Ardabil, Iran.

Methods: This study was a cross-sectional survey conducted during 2011-2014. A total of 110 serum samples collected from dogs either having or lacking clinical signs and tested by direct agglutination test (DAT) assay. Then 10 dogs (41.6%) showing clinical signs and 15 dogs (17.4%) without any symptoms were autopsied and their spleens were sampled. The samples were used for smear preparation and culturing.

Results: Based on the results, among 24 dogs with clinical signs 20 cases (83.3%) and of 86 dogs without signs, 16 cases (18.6%) found to be positive. On the other hand, smear and culture results were found to be positive in 100% and 60% of dogs with and without clinical signs, respectively. The interesting and impressive results of this study was that the dogs with symptoms but negative DAT and asymptomatic dogs with negative DAT were positive in parasitological tests.

Conclusion: This proves that asymptomatic dogs like symptomatic dogs can be effective in L. infantum infection and is able to maintain the transmission of the disease in endemic areas. On the other hand, a number of symptomatic dogs with negative anti-leishmania antibodies were positive in parasitological tests. Thus, this study also shows that although DAT is effective in determining asymptomatic dogs and canine visceral leishmaniosis control programs but it does not seem to be satisfying in endemic areas such as Meshkin-shahr. Thus in endemic areas, it is recommended that the low antibody titer should be considered.

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Leishmania parasites as the causative agent of leishmaniasis belong to Trypanosomatidae family. Parasite, vector, vertebrate host and environment are major factors in pathogenesis of Leishmania. 
Parasite dependent factors are virulence factors which exist in Leishmania species such as LPG, GP63. In recent years, the importance of these factors in the field of vaccine and drug has been considered by researchers. Sand fly biting behavior and salivary gland proteins are vector dependent factors which are effective in the Leishmania pathogenesis. Age, gender, nutrition, immune system, infectious diseases, genetic, occupation, socio-economic characteristics, and habitat are vertebrate host mediated factors. Temperature, rainfall, wind and its speed, soil, and continuous changes in climate are also environmental factors. Therefore the aim of this study was to evaluate the pathogenesis of Leishmania parasites.
 

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Background & objectives: Pentavalent antimonials are the first-line drugs for treatment of leishmaniasis, which have multiple side effects such as drug toxicity. Moreover, parasite resistance to these drugs is rising around the world. Second-line drugs, including Amphotericin B and pantamidine have also side effects and expensive for patients. According to the cytotoxic effects of paraquat, this study was conducted to evaluate the effect of paraquat on Leishmania major promastigotes and HUVECs viability.
Methods: A number of 2.5×10⁶ of Leishmania major promastigotes were treated in each well of 96 well plates with different concentrations of paraquat. Cells were incubated for 48 hours in 24 °C. MTT test was performed for evaluating paraquat impact on promastigotes. The absorbance was measured using a microplate reader at 570 nm.  The trypan blue staining assay was performed to evaluate the number of viable Leishmania major promastigotes following paraquat treatment. Furthermore, the effect of paraquat concentrations on HUVECs viability was evaluated under the cell culture condition.
Results: The results of the MTT test showed that increasing concentrations of paraquat could significantly reduce the viability and the number of Leishmania major promastigotes in comparison to control group (p<0.05). In this study, the IC₅₀ for Leishmania major promastigotes was calculated as 272.46 µg/ml. Trypan blue results were in line with the finding of MTT assay. Moreover, we found that HUVECs were susceptible to paraquat (IC₅₀=188.99 µg/ml).
Conclusion: Paraquat has a strong inhibitory effect on Leishmania major promastigotes and human endothelial cells. Although more comprehensive studies on the effects of the topical use of paraquat on Leishmania major lesions in animal model and its side effects are necessary.

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Leishmaniasis is a tropical parasitic disease that has become a major health challenge in many countries of the world. Not only has not been found any effective vaccine or treatment for the disease eradication, but also the advent of drug resistance is also increasing. Therefore, it is vital to take a precise attention to the physiochemical cycles of the Leishmania parasite and to identify its biochemical pathways. One of the most important biochemical pathways of host and parasite is the arginase and nitric oxide cycles. By using L-arginine, arginase plays an important role in the metabolic pathways, particularly in ornithine production, polyamines biosynthesis and cellular activities, including proliferation and cell survival. Furthermore, L-arginine, can act as a substrate for inducible nitric oxide synthase (iNOS), which leads to the synthesis of nitric oxide (NO), thereby activating the cellular immune system and clearing intracellular parasites. High Arginase activity reduces the parasite load inside the host cell, and since lymphocytes need L-arginine for their activity, its deficiency impairs the response of host immune cells. Also, parasites arginase alone can determine the fate of Leishmania parasite within the host cell. The aim of this study was to provide a comprehensive overview of various studies on the arginase activity of both parasite and host and its direct impacts on the immune system and pathogenicity of the Leishmania parasite.
 

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Background & objectives: Drug-repurposing is the study on application of existing drugs for treatment or control of other diseases. Major advantage of the technique relies on a nominated drug molecule that is applied for pharmacodynamics optimization due to lack of serious pharmacokinetics challenges. According to the importance of the subject, a present contribution has been dedicated to the in-silico analysis of a few drug classes with the aim of achieving potential anti-leishmanial pharmacophores.   
Methods: 3D structure of protein targets within leishmania parasite were retrieved from Brookhaven Protein Data Bank (PDB) on the basis of literature reports to evaluate the related complexes with drugs via molecular docking. Qualitative and quantitative analysis of drug-target interaction patterns in docked complexes offered drugs with higher binding affinities toward targets and finally structural patterns or hypothetical anti-leishmanial pharmacophores were proposed with regard to the top-ranked pharmaceutical compounds.
Results: Highest free binding energy could be estimated for Nateglinide in binding to farnesyl diphosphate synthase (ΔG_b -13.30 kcal/mol). Among steroids, Norgestrel synthase (ΔG_b -9.48 kcal/mol) and Testosterone synthase (ΔG_b -8.05 kcal/mol) exhibited higher enzyme binding affinities and Arg82 was a key residue in making hydrogen bonds. Within fused tricyclic structural patterns, mirtazapine exhibited highest binding affinity to deoxy uridine triphosphate (ΔG_b -8.64 kcal/mol). In Carbamazepine, amide substituent of the central ring facilitated the formation of two effective hydrogen bonds with Gln21 and Asn25 in deoxy uridine triphosphate. 
Conclusion: On the basis of obtained results for steroids and fused tricyclic scaffolds, it will be possible to design molecules that can inhibit several pathogenic targets simultaneously.

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Leishmaniasis is a parasitic infectious disease that accounts for approximately one million new cases annually. The treatment of this disease is complex and costly, particularly in developing countries. Numerous studies have been conducted on various vaccines utilizing live attenuated parasites, killed parasites, subunit antigens, recombinant vaccines, and DNA technology. However,  an effective and widely applicable preventive vaccine for leishmaniasis has not yet been developed. Present study aimed  to examine the progress in the development of leishmaniasis vaccines.
Articles for this study were selected from the PubMed, Web of Science and Scopus databases using relevant keywords, focusing on subject matter, scientific quality, and publication date, with an emphasis on more recent publications.
Research on the development of leishmaniasis vaccines indicates that several candidates, such as Leishmune, CaniLeish, and Leish-Tec, which are at various stages of clinical trials, may serve as suitable options for controlling and preventing leishmaniasis in dogs. The LeishChim vaccine, designed using immunoinformatics and molecular docking techniques, has shown promising efficacy results in mouse studies. Additionally, the mutant gene-centered LmCen-/- vaccine has completed Phase 1 clinical trials in humans.
Given the importance of developing a leishmaniasis vaccine, research in this area continues. Utilizing immunoinformatics and biological modeling studies can aid in the faster identification of effective vaccine candidates.