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Background: Recent studies have shown an increasing number of patients with cutaneous leishmaniasis (CL) who do not respond to pentavalent antimonials as the first line of treatment for CL. Nanocarriers such as extracellular vesicles (EVs) are efficient vehicles that might be used as drug delivery systems for the treatment of diseases. Therefore, we aimed to isolate and characterize the EVs of Leishmania major, load them with Amphotericin B (AmB), and investigate the toxicity and efficacy of the prepared drug form. Methods: The EVs of L. major were isolated, characterized, and loaded with amphotericin B (AmB), and the EVs-Amphotericin B (EVs-AmB) form was synthesized. Relevant in vitro and in vivo methods were performed to evaluate the toxicity and efficacy of EVs-AmB compared to the control. Results: The anti-leishmanial activity of the EVs-AmB showed a higher percentage inhibition (PI%) (P = 0.023) compared to the AmB at different concentrations and time points. Obtained data showed a significant increase in the lesion size and parasite load in the lesion, PBS, and EVs mice groups in comparison with EVs-AmB, AmB, and Glucantime groups (P < 0.05), EVs-AmB had a significant decrease in lesion sizes in comparison with AmB (P < 0.05). Results showed that EVs-AmB decreased its toxicity to the kidneys and liver (P < 0.05). Conclusion: EVs-AmB improved the efficacy of AmB in mouse skin lesions and reduced hepatorenal toxicity. Furthermore, EVs could be a promising nanoplatform for the delivery of AmB in CL caused by L. major. [ABSTRACT FROM AUTHOR]

Background: Detection of Leishmania RNA virus (LRV) in Old World Leishmania species and their possible role in the disease prognosis requires sensitive and specific methods, preferably independent of the viral genome. We aimed to develop an indirect immunofluorescence antibody (IFA) assay to detect LRV in the Old World Leishmania parasites. Methods: Clinical samples were collected from 86 cutaneous leishmaniasis (CL) patients in different endemic areas of CL in Iran, during 2017-2019. For antibody preparation, the viruses were obtained from sediment of an LRV-infected L. major culture-using freeze and thaw cycles followed by gradient cesium chloride centrifugation. The purified viruses were used to immunize a male 3-4 months rabbit. Various dilutions of the LRV-immunized rabbit's serum and a conjugated antibody were deployed to detect LRV in 48 isolates by IFA assay. Results: LRV virus was detected in four of the 48 CL cases using IFA method. Amplification of a partial fragment of RNA-dependent RNA polymerase (RdRp) gene from the isolates confirmed the IFA results. In phylogeny, the generated RdRp sequences from four isolates were grouped with the other Old World LRVs, but separate from L. aethiopica LRVs, which appeared as a highly supported distinct clade. Conclusion: Further optimization of this approach to detect the LRV directly in lesion scrapings can make it a more reliable tool for field studies and disclosing the virus's possible role in disseminating and unusual clinical features. [ABSTRACT FROM AUTHOR]

Background: Cutaneous leishmaniasis (CL) is a vector borne disease predominantly found in tropical and subtropical countries, including Iran. For more than 6 decades, pentavalent antimonials have been used successfully worldwide for the treatment of leishmaniasis, but over the past few years, clinical resistance to these medications has increased. In this study, we evaluated CL patients who did not show any desirable responses to the anti-leishmanial treatment within a 10- year period (2008 to 2017). Methods: All patients from different parts of Iran suspected of having cutaneous leishmaniasis, who were referred to the laboratory of leishmaniosis in Tehran University of Medical Sciences from 2008–2017 were parasitological examined. Results: During this period, a total of 1480 suspected CL patients were referred to the laboratory of leishmaniosis. Samples from 655 patients (70.8%) suspected of having CL were positive microscopically. The failure rate in patients treated with anti-leishmaniasis medications for a minimum of three complete treatment periods was 1.83% (12 cases). There was no association between the number and size of skin lesions and patient characteristics. Also, the route of drug administration had no significant effect on the number and size of lesions. Conclusion: In the present study, treatment failure was found in some confirmed CL patients treated with meglumine antimoniate. Over the past few years, it seems that had been increased in resistance to these medications. So, a review of the correct implementation of the treatment protocol and/or a combination therapy may be helpful in preventing an increase in the rate of treatment failure. [ABSTRACT FROM AUTHOR]

Introduction: Cutaneous leishmaniasis (CL) is among the top 10 infectious disease priorities in the world, and the leading cause of morbidity in Iran. The present study was conducted to assess the risk of CL, and to determine some epidemiological features of the disease in endemic areas of Qom Province in Central Iran during 2009 to 2013. Methods: Data regarding human cases of the disease were obtained from the Qom Province Health Center, prepared and stored in a spatial database created in ArcGIS10.3. A total of 9 out of 212 Leishmania spp. positive slides taken in 2013 from patients residing in Qom city were examined using molecular methods and the species of Leishmania was identified by PCR-RFLP. Those 9 patients had no history of travel outside the city. Spatial analysis and clustering methods were applied to find major hot spots and susceptible areas for the establishment of novel foci of the disease. Transmission patterns were examined for spatial autocorrelation using the Moran's I statistical application, and for the clustering of high or low values using the Getis-Ord Gi* statistics. Results: During the period of study, a total of 1767 CL cases were passively reported in the area, out of which were 65% males and 35% females. The highest and lowest numbers of cases were reported in 2010 and 2013, respectively. Importantly, 979 cases were reported from urban areas, while the remainder came from rural areas. Leishmania major was detected as the causative agent of CL in the city of Qom. Remarkably, most patients recorded in Qom city were associated with a history of travel to the endemic areas of CL within the province, or to other endemic areas of the disease in Iran. Spatial distribution of CL cases revealed northeastern and southwestern quarters of the city were the major hot spots of the disease (P<0.05). Hot spot and CL transmission risk analysis across the province indicated that more than 40 villages were located in high and very high risk areas of CL transmission. Conclusions: Due to the existence of hot spots (P<0.05) of CL in successive years in some quarters of Qom city, along with detection of L. major from the patients without a history of travel, there may be potential of local transmission of the disease within the city. Therefore, it is necessary to conduct a comprehensive study concerning the hot spots of CL in Qom city for curtailing the incidence of the disease in the city. The methodology and the results of this study is essential in serving as a yardstick for subsequent similar studies that will be carried out in other endemic areas of CL in Iran and providing an adequate tool for the establishment of a national database of cutaneous leishmaniasis. [ABSTRACT FROM AUTHOR]

Background: Cutaneous Leishmaniasis (CL) is a parasitic disease with diverse outcomes. Clinical diversity is influenced by various factors such as Leishmania species and host genetic background. The role of Leishmania RNA virus (LRV), as an endosymbiont, is suggested to not only affect the pathogenesis of Leishmania, but also impact host immune responses. This study aimed to investigate the influence of LRV2 on the expression of a number of virulence factors (VFs) of Leishmania and pro-inflammatory biomarkers. Materials and methods: Sample were obtained from CL patients from Golestan province. Leishmania species were identified by PCR (LIN 4, 17), and the presence of LRV2 was checked using the semi-nested PCR (RdRp gene). Human monocyte cell line (THP-1) was treated with three isolates of L. major with LRV2 and one isolate of L. major without LRV2. The treatments with four isolates were administered for the time points: zero, 12, 24, 36, and 48 h after co-infection. The expression levels of Leishmania VFs genes including GP63, HSP83, and MPI, as well as pro-inflammatory biomarkers genes including NLRP3, IL18, and IL1β, were measured using quantitative real-time PCR. Results: The expression of GP63, HSP83, and MPI revealed up-regulation in LRV2 + isolates compared to LRV2- isolates. The expression of the pro-inflammatory biomarkers including NLRP3, IL1β, and IL18 genes in LRV2- were higher than LRV2 + isolates. Conclusion: This finding suggests that LRV2 + may have a probable effect on the Leishmania VFs and pro-inflammatory biomarkers in the human macrophage model. [ABSTRACT FROM AUTHOR]

• Leishmania RNA Virus 2 was detected in 59 (69.4%) of the Cutaneous Leishmaniasis cases studied. • For the first time, Leishmania RNA Virus 2 was reported in one L. tropica strain in Iran. • Ten unique haplotypes were identified based on the analyzed sequences of the RdRp gene. 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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

Pentavalent antimonials remain the treatment of choice for all the clinical forms of leishmaniasis. The increasing rates of antimony resistance are becoming a serious health problem in treatment of anthroponotic cutaneous leishmaniasis (ACL). Accordingly, unraveling molecular markers is crucial for improving medication strategies and monitoring of drug-resistant parasites. Different studies have suggested the importance of genes involved in trypanothione metabolism and drug transport. In this regard, present study was designed to investigate the RNA expression level of five genes including γ-GCS, ODC, TRYR (involved in trypanothione metabolism), AQP1 (acts in drug uptake) and MRPA (involved in sequestration of drug) in sensitive and resistant Leishmania tropica isolates. Seven antimony-resistant and seven antimony-sensitive L. tropica clinical isolates were collected from ACL patients. Drug sensitivity test was performed on the samples as well as reference strains; afterwards, gene expression analysis was performed on clinical isolates by quantitative real-time PCR. The results revealed that the average expression level of AQP1 gene was decreased (0.47-fold) in resistant isolates compared to sensitive ones whereas MRPA (2.45), γ-GCS (2.1) and TRYR (1.97) was upregulated in resistant isolates. The average expression of ODC (1.24-fold) gene was not different significantly between sensitive and resistant isolates. Our findings suggest that AQP1, MRPA, GSH1 and TRYR can be considered as potential molecular markers for screening of antimony resistance in some L. tropica clinical isolates. [ABSTRACT FROM AUTHOR]

Background: Leishmaniasis is currently considered a re-emerging or emerging infection based on the geographic region. The outcome of leishmaniasis vastly depends on Leishmaniahost interaction. This preliminary study aimed to show the association of human leukocyte antigen (HLA) class I and II genes with healed and non-healed cutaneous leishmaniasis (CL), and symptomatic and asymptomatic visceral leishmaniasis (VL) compared with control groups in Iran. Methods: Ninety-five people, including 31 patients versus 64 individuals in the control group, were enrolled. Among them, 20 patients had confirmed CL based on amastigote observation, 10 had improved CL and 10 non-healed CL. Eleven patients were suffering from confirmed VL based on direct agglutination test (Five asymptomatic and six symptomatic VL cases). Besides, they were residents in an endemic area of VL in the northwest of Iran. To select a control group, it was ensured that they had no history of leishmaniasis. Peripheral blood samples were collected from each patient. After DNA extraction, HLA typing was conducted using polymerase chain reaction - sequence-specific priming (PCR-SSP). Subsequently, data were statistically analyzed by SPSS. Results: There was a statistical relationship between the presence of HLA-A26 and CL, healed CL and the existence of the B38 allele, C1 allele and symptomatic VL, as well as B1.4 allele and asymptomatic VL (P<0.05). Conclusion: This primary finding indicates that several HLA genes have a potential role in the susceptibility of Iranian people to CL and VL. [ABSTRACT FROM AUTHOR]

Background: Pentavalent antimonial has been a drug of choice against leishmaniasis, despite the emergence of treatment failure. Identification of resistance markers is urgently needed to design new therapeutic strategies. Iron-Superoxide dismutases (Fe-SODs) are antioxidant enzymes contributing to detoxify reactive oxygen species to prevent a cell from oxidative stress. Since antimonial compounds induce oxidative stress, in this survey, the expression of SOD genes was investigated to identify their expression pattern in clinical resistant isolates. Methods: This cross-sectional survey was done in Mashhad City, northeast of Iran during 2014 to 2019. The RNA expression level of mitochondrial (SODA) and glycosomal (SODB) superoxide dismutase was investigated in 25 antimony responsive (n=15) and unresponsive (n=10) anthroponotic cutaneous leishmaniasis (ACL) patients. Total RNA extraction and cDNA synthesis, the qRT-PCR approach was utilized to investigate the relative RNA expression level. Results: The transcript level of SODs was over-expressed in the most resistant isolates. Gene expression analysis demonstrated the over-expression of SODA and B by a factor of 3.8 and 4.81, respectively, in resistance isolates vs. sensitive ones. Conclusion: Aberrant expression of SODA/B in unresponsive parasites could potentially implicate in detoxifying antimony-induced oxidative stress. Moreover, SODs might be considered as potential predictive markers of the response to antimonials in ACL patients in endemic areas. [ABSTRACT FROM AUTHOR]

Background: Cutaneous leishmaniasis (CL) is described as a major health problem in many countries of the world. Regulatory T cells (Tregs) are characterized as one of immunologic indexes. One of the best methods to determine of Tregs percentage is flow cytometry. The aim of this study was determination of the role of Tregs profile among acute and chronic forms of human CL using flow cytometry analysis. Methods: This study was conducted on 24 patients referred to Laboratory of Leishmaniasis, Tehran University of Medical Sciences, Tehran, Iran with acute and 14 patients with chronic phases of CL as well as 15 healthy individuals as control group in 2015-2016. After microscopic examination, 2 ml of peripheral blood samples were collected for determining percentage of CD4 + CD25 + CD127 low Tregs by using flow cytometry method. Results: Using flow cytometry analysis, the average percentage of Tregs were calculated 5.73, 6.71 and 6.61 for acute, chronic and healthy individuals, respectively. With SPSS software and Scheffe multiple comparison tests, the differences within in these groups are statistically significant (P=0.04) and between the acute and chronic group, there was marginally significant with approximately 91% of confidence level (P=0.088). Conclusion: Marginally differences were found significantly among averages of Regulatory T cells, acute and chronic phases of CL. Further comprehensive studies can be needed to verify the role of Tregs in both phases of CL cases. [ABSTRACT FROM AUTHOR]

Background: Visceral leishmaniasis (VL) is endemic in the northwest and south of Iran. Untreated cases of VL could cause death. The aim of the present study was to evaluate the diagnostic performance of western blotting to detect a specific immunodominant proteins pattern for Leishmania infantum infection using human sera infected with VL. Methods: We studied a panel of 122 cryopreserved human serum samples from the leishmaniasis Research Laboratory, Tehran University of Medical Sciences, Tehran, Iran from 2010 to 2017. Serum samples were collected from visceral (Group I, n: 43) and cutaneous leishmaniasis (CL) (Group II, n: 8) patients, healthy individuals from endemic (Group III, n: 13) and non-endemic (Group IV, n: 16) areas for VL, and patients with other infectious diseases (Group V, n: 42). Total antigens were prepared from the Iranian strain of L. infantum promastigote form. Results: In western blotting method, 34 protein bands of 14 to 163 kDa were recognized using the sera of VL patients. The polypeptide fractions with the highest frequency including 29, 51, and 62 kDa fractions were detected using 81.4%, 79%, and 81.4% of the sera, respectively. These bands were not detected using the sera of the negative control. Moreover, 19–23, 27, 31–35, 143–163, and 109 kDa fractions were detected specifically using the sera of the patients with VL. Conclusion: This technique could be a primary step for further exploration of VL immunodominant antigens for cloning (or any technique) further investigations for future planning. [ABSTRACT FROM AUTHOR]

Background: Leishmaniasis is a major medical health problem and distributes in nearly half of 31 provinces of Iran. We aimed to identify cutaneous and visceral Leishmania spp. isolated from infected humans and domestic dogs in various regions of Iran, 2010-2013. Methods: DNA was extracted from 108 lesion exudate samples of suspected patients to cutaneous leishmaniasis and nine liver and spleen aspirates of infected dogs cultured in RPMI-1640 and amplified using partial sequence of ITS1 gene. The PCR amplicons were digested using HaeIII endonuclease enzyme and used in restriction fragment length polymorphism (RFLP) assay. Then, 48 amplicons representing various hosts were sequenced and compared to sequences from GenBank databases using BLAST. Results: PCR-RFLP analysis showed that 60 and 48 CL patients were infected by Leishmania tropica and L. major, respectively. From nine canine visceral leishmaniasis (CVL) isolates, eight isolates were identified as L. infantum and one as L. tropica. The greatest similarity of 95.7% in ITS1 region was seen between L. infantum and L. major. Furthermore, the lowest similarity with 65.7% was seen between L. tropica and L. major. Intra-species comparison of ITS1 region in L. infantum, L. major and L. tropica isolates were showed 100%, 98.2% and 72.4 % similarities, respectively. Conclusion: PCR-RFLP based on ITS1 region is an appropriate method to distinguish three Leishmania spp. of L. major, L. tropica, and L. infantum. In intra-species comparison of ITS1 region, genotypic variations showed that L. tropica isolates were more heterogeneous than L. major and L. infantum isolates. [ABSTRACT FROM AUTHOR]

Background: Cutaneous leishmaniasis (CL) is one of the world health problems. Leishmania major is the etiological agent of zoonotic cutaneous leishmaniasis (ZCL). Promastigote and amastigote are two morphological forms of Leishmania parasites that express different proteins and p27 is an important gene encoding cytochrome c oxidase (COX) component. P27 gene expresses a 27 kDa protein that essential in ATP synthesis. This study aimed to compare p27 gene expression in promastigote and amastigote forms in Iranian strain of L. major (MRHO/IR/75/ER). Methods: This study was conducted in 2015. Clinical isolates of CL patients from north, center, west and south parts of Iran were collected and identified by PCRRFLP. After RNA extraction of promastigotes and amastigotes and cDNA synthesis, the expression level of p27 gene was compared by real-time RT-PCR. Results: By comparison of expression level between amastigote and promastigote forms of Iranian strain of L. major, up-regulation of p27 gene (2.73 fold) was observed in amastigotes. Moreover, there was no significant difference in p27 gene expression between L. major isolates. Conclusion: p27 gene and protein can be considered as a target in recombinant vaccine production and treatment process. [ABSTRACT FROM AUTHOR]

Background: Cutaneous leishmaniasis (CL) is one of the most important neglected tropical diseases and a major public health challenge in Iran caused by Leishmania spp and transmitted by phlebotomine sand flies. The number of CL cases has shown an increasing pattern all over the country, including the district of Varamin, southeast of Tehran, Iran. This study aimed to identify the Leishmania spp isolated from CL patients using molecular methods in Varamin during 2012-2013. Methods: Exudate materials collected from the swollen edge of the skin lesions of 44 parasitological positive CL patients by disposable lancet. They were referred to Varamin Health Center by physician. The samples were subjected to molecular method for Leishmania species identification. Results: The digestion pattern of restriction enzyme revealed that 37 (84.1%) CL patients were infected with L. major and 7 (15.9%) were infected with L. tropica. They were mostly male than female. More than half of the patients (58%) had multiple lesions, and they were mostly observed on extremities, 34.1% on legs and 29.5% on hands. Le- sions were mostly of wet ulcerative type. Conclusion: Dominancy of L. major provides more evidence that Varamin District probably could be considered as Zoonotic Cutaneous Leishmaniasis (ZCL) areas. More investigation on other epidemiological aspects of disease is needed. [ABSTRACT FROM AUTHOR]

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. • Leishmania RNA Virus 2 was detected in 13 (15.3%) of cutaneous leishmaniasis isolates studied. • Leishmania RNA Virus 2 in one L. tropica in Isfahan province, Iran was reported. • Our sequences analysis demonstrated LRV2 isolated from Isfahan are genetically similar to other LRV2 from the Old World [ABSTRACT FROM AUTHOR]

• Among the 181 gerbils captured, 48.6% were Leishmania spp. positive upon microscopic examination. • Leishmania infection was observed in 89.5% of the gerbils using nested-PCR. • Single or mixed infections of L. major with L. gerbilli or L. turanica were detected in 28.4% gerbils. • Homology investigation using NCBI blast against Genbank database sequences revealed 92.45–100% homology between samples and L. major in the Genbank sequences using ITS2-rDNA. Rodents from the subfamily Gerbillinae are the principal reservoir of cutaneous leishmaniasis (CL) caused by Leishmania major in the center and northeast of Iran. This study was conducted to determine both naturally occurring Leishmania infection rates and the distribution of Leishmania species in the central parts of Iran during 2019–2020. In this regard, presence of Leishmania parasites were confirmed by microscopic examination and the species were identified by nested-PCR using the Internal Transcribed Spacer2- Ribosomal DNA (ITS2-rDNA). Finally, some samples were sequenced and, the blast analysis of L. major samples, showed a 92.45–100% homology to the L. major sequence. Of the 181 wild gerbils collected (Rhombomys opimus =157 and Meriones lybicus =24), 88 (48.6%) tested positive for Leishmania sp. by microscopic examination whereas 162 (89.5%) were positive by nested-PCR. Of the 162 infected gerbils, 103 showed single strain infections (30 L. major, 28 L. gerbilli and 45 L. turanica) , 43 showed dual infections with only the non-human species (L. gerbilli and L. turanica) , and 16 were mixed infections of L. major and L. turanica (n = 14) or L. gerbilli (n = 2). All single or mixed L. major infections were detected in gerbils from areas with reports of human CL during the last decade. These findings suggest that Rhombomys opimus and Meriones libycus have a potential role in the maintenance of human and non-human transmission of Leishmania species in the CL foci. [ABSTRACT FROM AUTHOR]

Cutaneous leishmaniasis (CL) is an endemic disease in some parts of Iran and it has high morbidity in some areas of the country. The disease is detected by parasitological examinations including direct microscopic and culture tests. This comparative study aimed to evaluate the relationship between positivity of the leishmanin skin test (LST), microscopically examination and clinical forms of CL for the diagnosis of human cutaneous leishmaniasis. This study was performed on 66 patients suspected to cutaneous leishmaniasis. CL cases evaluated by both microscopical examination and leishmanin skin test. In this study, 1 ml of leishmanin fluid (lot no 121/1, produced in Pasteur institute of Iran) was injected intradermally in forearms of all patients and indurations were measured after 72hours. Induration of 5 mm and higher was considered as positive results. The collected data were statistically analyzed using the SPSS version 13.5. From 66 CL patients who were evaluated in this study, 30 (45.5%) of them had positive microscopically results while 28(42/4%) of them had showed positive leishmanin skin test (≥5mm diameter). From 36 (54.5%) patients who had negative microscopical examination, only 6(16/6%) of them had positive leishmanin skin test. The agreement between two tests was 87.9 % by kappa analysis (p< 0.01). In attention to the results of this study, it seems the LST would be used as an alternative diagnosis method when there is a strong clinical doubt to cutaneous leishmaniasis even there is no parasite in direct smear. [ABSTRACT FROM AUTHOR]

Background: Recent circumstantial evidence suggests that an increasing number of Iranian patients with cutaneous leishmaniasis are unresponsive to meglumine antimoniate (Glucantime), the first line of treatment in Iran. This study was designed to determine whether the clinical responses (healing, or non-healing) were correlated with the susceptibility of Leishmania parasites to Glucantime.Methods and Findings: In vitro susceptibility testing was first performed on 185 isolated parasites in the intracellular mouse peritoneal macrophage model. A strong correlation between the clinical outcome and the in vitro effective concentration 50% (EC50) values was observed. Parasites derived from patients with non-healing lesions had EC50 values at least 4-fold higher than parasites derived from lesions of healing patients. A selection of these strains was typed at the molecular level by pulsed-field gels and by sequencing the pteridine reductase 1 (PTR1) gene. These techniques indicated that 28 out of 31 selected strains were Leishmania tropica and that three were Leishmania major. The L. major isolates were part of a distinct pulsed-field group, and the L. tropica isolates could be classified in three related additional pulsed-field groups. For each pulsed-field karyotype, we selected sensitive and resistant parasites in which we transfected the firefly luciferase marker to assess further the in vitro susceptibility of field isolates in the monocyte cell line THP1. These determinations confirmed unequivocally that patients with non-healing lesions were infected with L. tropica parasites resistant to Glucantime. Additional characterization of the resistant isolates showed that resistance is stable and can be reversed by buthionine sulfoximine, an inhibitor of glutathione biosynthesis.Conclusions: To the authors' knowledge, this is the first report of proven resistant parasites contributing to treatment failure for cutaneous leishmaniasis and shows that primary Glucantime-resistant L. tropica field isolates are now frequent in Iran. [ABSTRACT FROM AUTHOR]