In vitro and in vivo anti-parasitic activity of curcumin nanoemulsion on Leishmania major (MRHO/IR/75/ER)

The present study aimed to assess the anti-leishmanial effects of curcumin nanoemulsion (CUR-NE) against Leishmania major (MRHO/IR/75/ER) in both in vitro and in vivo experiments. CUR-NE was successfully prepared via the spontaneous emulsification method. The in vitro effect of various concentrations of CUR-NE against L. major promastigotes was assessed using the flow cytometry method. In vivo experiments were carried out in BALB/c mice inoculated subcutaneously with 2 × 106 L. major promastigotes. Mice were treated with topical CUR-NE (2.5 mg/ml), intra-lesion injection of CUR-NE (2.5 mg/ml), topical CUR suspension (CUR-S, 2.5 mg/ml), topical NE without CUR (NE-no CUR), amphotericin B as the positive control group, and infected untreated mice as the negative control group. In vitro exposure of promastigotes to CUR-NE showed a dose-dependent anti-leishmanial effect, with a 67.52 ± 0.35% mortality rate at a concentration of 1250 µg/ml and an IC50 of 643.56 µg/ml. In vivo experiments showed that topical CUR-NE and CUR-S significantly decreased the mean lesion size in mice after four weeks from 4.73 ± 1.28 to 2.78 ± 1.28 mm and 4.45 ± 0.88 to 3.23 ± 0.59 mm, respectively (p = 0.001). Furthermore, CUR-NE significantly decreased the parasite load in treated mice compared with the negative control group (p = 0.001). Results from the current study demonstrated the promising activity of CUR-NE against L. major in both in vitro and in vivo experiments. Moreover, CUR-NE was more efficient than CUR-S in healing and reducing parasite burden in mouse models. Future studies should aim to identify molecular mechanisms as well as the pharmacologic and pharmacokinetic aspects of CUR-NE.

Leishmania major Infection in Synanthropic Rodents: Evidence for the Urbanization of Zoonotic Cutaneous Leishmaniasis (ZCL) in Southern Iran

Cutaneous leishmaniasis is of particular importance in southern Iran. This study aimed to investigate the infection of rodents with Leishmania major in an urban area of Fars Province, located in southern Iran. Rodents were trapped and samples from the liver, spleen, and skin were collected. Impression smears were prepared from these tissues and any skin lesions and were examined microscopically. In addition, a portion of the samples were preserved for subsequent DNA extraction. A total of 41 rodents belonging to three species were caught from 10 trapping stations in gardens or houses within the area. The caught rodent species were Rattus rattus (n = 25, 60.97%), Mus musculus (n = 15, 36.58%), and Meriones persicus (n = 1, 2.5%). Leishmania amastigotes were seen in the spleen tissue smear of 6 (2.43%) of the rodents, including 4 of R. rattus and 2 of M. musculus. Skin lesions were observed on the muzzles of two R. rattus and one M. musculus. Samples taken from these lesions tested positive for Leishmania infection. Leishmania DNA was detected in 18 (43.9%) rodents, including 11 R. rattus, 6 M. musculus, and one M. persicus, based on DNA sequencing of the ITS2 gene and PCR of the kDNA. Phylogenetic reconstruction revealed that the parasite infecting the rodents was L. major. The detection of Leishmania infection in these rodents in urban areas raises concerns about the urbanization of cutaneous leishmaniasis caused by L. major. This urbanization poses unique challenges for control and prevention efforts.

Detection of Leishmania donovani using ITS1-RFLP from positive and negative smear samples among clinically reported patients visiting University of Gondar Comprehensive Specialized Hospital

BACKGROUND

Visceral leishmaniasis is caused by the Leishmania donovani species complex that can spread to internal organs and leading to death if not treated on time. Diagnosis of leishmaniasis is based on clinical signs and symptoms, microscopy, serological and molecular techniques. Because of a broad spectrum of diverse clinical manifestations and similarities of the responses to different species, identification to the species level is often difficult for the proper patient treatment and management. Therefore, the objective of this study was to evaluate the PCR- RFLP assay of the ITS1 region for identification of L. donovani species from clinical smear slide patient samples.

METHOD

DNA extraction was performed on a total of 90 smear slide samples using phenol-chloroform method. The PCR detection limit was determined by L. donovani reference strain DNA. The ITS1 region was amplified at 320 bp using LITSR/L5.8S genus specific primers and then the ITS1-PCR products were subjected to RFLP assay for confirmation of L. donovani species using HaeIII restriction enzyme.

RESULTS

Of the total samples ITS1-PCR revealed the true positive, false positive, true negative, and false negative results of 42 (46.7%), 6 (6.7%), 37 (41.1%) and 5 (5.6%), respectively. Considering microscopy as the gold standard, the sensitivity, specificity, positive predictive values, and negative predictive values of the ITS1- PCR technique was 89.4%, 86.0%, 87.5%, and 88.1% respectively. All ITS1-PCR positive clinical samples were confirmed as L. donovani species by PCR-RFLP patterns.

CONCLUSION

In conclusion, the ITS1- RFLP method is highly sensitive and more specific for identification of L. donovani species in the smear negative clinical samples of visceral leishmaniasis patients. There is also significant association and degree of agreement between the two methods. For direct identification of L. donovani species from clinical samples, irrespective of genus and species level, PCR-RFLP is more recommendable than a microscope.

Cytotoxic screening and in vitro effect of sodium chlorite against Leishmania major promastigotes

Cutaneous leishmaniasis (CL) is one of the most important parasitic diseases in the world. Despite the existence of many therapeutic strategies, the treatment of this infection still faces problems. Sodium chlorite as an antimicrobial agent has been shown to have acceptable tissue regenerative and wound healing properties. Therefore, the present study aimed to analyze the in vitro effects of different concentrations of sodium chlorite on Leishmania major promastigotes and macrophage cells. The inhibitory and toxicity effect of various concentrations (0.0035, - 1.8 mg/ml) of sodium chlorite on the standard Iranian strain of L. major promastigotes were evaluated via counting the cells and flow cytometry. Furthermore, cytotoxicity on promastigotes and J774 macrophage cell line were performed by MTT assay. The results of the inhibitory test demonstrated that sodium chlorite had dose-dependent, anti-leishmanial activities. The half-maximal inhibitory concentration (IC50) for promastigotes and J774 cells by cytotoxicity test was detected at 0.17 mg/ml and 0.08 mg/ml after 48 h respectively. Flow cytometry results showed that 27.34% death of promastigotes was observed in 0.0035 mg/ml of sodium chlorite and 78.12% in 1.8 mg/ml. The results of the present study showed that sodium chlorite could be used as an effective treatment for CL, especially in cases resistant to treatment with pentavalent compounds. However, the toxicity of this substance in high concentrations should be considered in clinical setting.

Molecular Identification of Leishmania Species in an Outbreak of Re-Emerged Cutaneous Leishmaniasis in Southwestern Iran During 2015 - 2016

Background: Dezful and its suburbs, as the second city in Khuzestan Province, southwest of Iran, has been an endemic area of cutaneous leishmaniasis (CL) with a low incidence rate since the last decades. However, the disease incidence has rapidly increased, and now is considered as a re-emerging parasitic disease in the area. Objectives: The aim of this study was to identify the most prevalent CL species in Dezful Region. Methods: A total of 196 microscopically confirmed slides from CL patients referred to Dezful Health Center were randomly collected in the period of 2015 - 2016. After DNA extraction from microscopically positive slides, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was carried out on 61 eligible specimens using ribosomal internal transcribed spacer 1 (ITS1) gene. The HaeIII restriction enzyme was used for the identification of species. Results: Samples were randomly collected from 196 acute CL cases, including 110 (56.2%) males and 86 (43.8%) females. Most infections were seen in the age range of 2 - 7 years (65/196, 33.1%). Totally, 60.1% of the cases had only one lesion, and half of the lesions appeared on hands. Furthermore, 162 (82.7%) cases were referred to Dezful Health Center in the cold seasons (autumn and winter). Results of PCR-RFLP on 61 eligible isolates showed that 60 (98.4%) isolates were Leishmania major, and only 1 (1.6%) isolate was Leishmania tropica. Conclusions: Our findings indicated that L. major is the main agent of re-emerged CL in Dezful and its suburbs, and the disease is a zoonosis.

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.

Expression analysis of centrin gene in promastigote and amastigote forms of leishmania infantum iranian isolates: a promising target for live attenuated vaccine development against canine leishmaniasis

Background

Leishmania parasites express various essential proteins in different growth phases (logarithmic/stationary) and forms (promastigote/amastigote). Targeting the genes encoding such proteins paves the way for controlling these parasites. Centrin is an essential gene, which its protein product seems to be vital for the proliferation of Leishmania parasites. Herein, this study was contrived to analyze the expression level of the centrin gene in different growth phases and forms of Leishmania infantum (L. infantum) parasites isolated from various endemic areas of canine leishmaniasis (CanL) in Iran.

Results

All three collected isolates were identified as L. infantum using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Real-time reverse transcription (RT)-PCR revealed a statistically significant up-regulation (3.13-fold) in the logarithmic phase promastigotes compared to stationary ones (p < 0.01), whereas centrin was expressed equally in intracellular amastigotes at different time points during cell culture. Also, our finding revealed a slight up-regulation of the centrin gene (1.22-fold) in the intracellular amastigotes compared to logarithmic phase promastigotes, which was found statistically non-significant (p > 0.05).

Conclusions

Centrin gene in Iranian isolates of L. infantum is more expressed in exponential than stationary phases and seems to be considered as a promising target in the development of a genetically modified live attenuated vaccine for CanL control.

Cutaneous leishmaniasis in Iran: A systematic review and meta-analysis

Cutaneous leishmaniasis as a public health concern that attracts many attentions in endemic area. There is no exact estimation of cutaneous leishmaniasis in Iran. This study aimed to assess the exact prevalence of disease and carried out in databases including: Pub Med, Google Scholar, Science Direct, Scopus, Web of Science, Magiran, Iran doc, Barakatkns and Scientific Information Database (SID) from 2000 to 2019. Totally 84 studies were eligible to be included in this systematic review and Meta-analysis study. Based on a random effect model the pooled prevalence of leishmaniasis was estimated 45% (95% CI: 39%-51%; I^2 = 99.8%P < 0.001). The highest prevalence of CL was related to Isfahan 66% (53%-78%), Golestan 64% (62%-65%) and Fars province 63% (38%-84%) and the lowest prevalence was estimated in Kermanshah province 4% (4%-5%), Hormozgan 10% (8%-11%), Bushehr 12% (1%-35%) and Kerman 15% (9%-22%) provinces respectively. The lowest prevalence was associated with L. trapica spices 23% (11%-38%) and the highest was associated with L. major spices 32% (21%-45%). The prevalence with both L. trapica and L. major spices was achieved 60% (48%-71%). It is essential for health authorities to take steps to control and prevent the epidemic by rapid treatment of patients, destroying gerbils and promotion of general and health education for the local population.

Comparative PCR-based diagnosis for the detection of Leishmania infantum in naturally infected dogs

The applicability of molecular biology/PCR for canine visceral leishmaniasis diagnosis presents challenges, mainly due to the diversity of targets described. The objectives of this study were to compare the sensitivities and reliability of five targets (kDNA/120, kDNA/145, ITS1, hsp70/234 and hsp70/1300) in four different tissue samples (bone marrow, popliteal lymph node, skin and conjunctival swab). Sixty-five dogs (32 males and 33 females) naturally infected with Leishmania infantum and ten dogs without infection were examined. Dogs were characterized by serological and parasitological methods. The parasitological test was considered the gold standard for analysis. All tests presented high specificity 100% (95% CI 0.72-1), and variable sensitivity. The targets kDNA/145, ITS1, kDNA/120, hsp70/234 and hsp70/1300 detected 100% (65/65), 93.4% (61/65), 92.3% (60/65), 84.61% (55/65) and 72.3% (77/65) of positive animals respectively. The performance of PCR methods was analyzed in two different scenarios. The highest sensitivity value identified in all scenarios studied was kDNA/145. Our results suggest that popliteal lymph node and conjunctival swab samples, besides being less invasive collections, represent a good substratum for PCR-based diagnosis, and the target kDNA/145 is the best choice for detecting L. infantum DNA in naturally infected dogs.

A highly sensitive modified nested PCR to enhance case detection in leishmaniasis

BACKGROUND

Human leishmaniasis is one of the major parasitic diseases with worldwide distribution. Sri Lanka is a recently established focus of leishmaniasis caused by a variant Leishmania donovani. Early case detection and management is a main approach identified for L. donovani control in the regional leishmaniasis elimination drive. Usefulness of light microscopy and in-vitro culture are limited in chronic, atypical or treated lesions though timely and accurate detection of all light microscopy/in-vitro culture negative cases of all forms of leishmaniasis is necessary for treatment. Timely treatment is important to minimize risk for death in visceral disease and undesired sequelae of long standing infection and illness on both patients and community. We described a 100% sensitive, Leishmania spp. specific modified version of a nested PCR (Mo-STNPCR) that also minimizes carry over and cross contaminations while facilitate investigation of light microscopy and in-vitro culture negative clinically suggestive cases of leishmaniasis.

METHODS

Leishmania DNA was amplified using previously published P221: 5'-GGTTCCTTTCCTGATTTACG-3' and P332: 5'-GGCCGGTAAAGGCCGAATAG-3'outer primers followed by a nested reaction using P223: 5'-TCCCATCGCAACCTCGGTT-3' and P333: 5'-AAGCGGGCGCGGTGCTG-3' inner primers that by passes the requirement of tube handling between the two steps of the conventional nested PCR. Leishmania DNA was detected in a range of infected tissue material. Infected material from patients with cutaneous leishmaniasis (n = 30), visceral leishmaniasis (n = 10) and from a control group including patients with non-leishmanial skin diseases (n = 10), other systemic diseases (n = 10) and healthy individuals (n = 10) were examined with Mo-STNPCR. Results were further compared with those of light microscopy and in-vitro culture.

RESULTS

Mo-STNPCR method was 100% sensitive and 100% specific for diagnosis of leishmaniasis. Light microscopy and in-vitro culture were positive in 75.0% (n = 30/40) and 72.5% (n = 29/40) samples respectively where combined results of them gave 87.5% (n = 35/40) sensitivity. Mo-STNPCR did not cross react with control samples. Furthermore, Mo-STNPCR reduces the risk of cross-contaminations and carry over contaminations since the full reaction is carried out without opening the tubes. Per patient cost was calculated as 22 USD while the same was 3 and 6 USD for light microscopy and in-vitro culture respectively.

CONCLUSION

Mo-STNPCR method is a useful tool in detecting leishmaniasis in minority of cases that go undetected by first line investigations.

Nonconventional opponents: a review of malaria and leishmaniasis among United States Armed Forces

As the United States military engage with different countries and cultures throughout the world, personnel become exposed to new biospheres as well. There are many infectious pathogens that are not endemic to the US, but two of particular importance are Plasmodium and Leishmania, which respectively cause malaria and leishmaniasis. These parasites are both known to cause significant disease burden in their endemic locales, and thus pose a threat to military travelers. This review introduces readers to basic life cycle and disease mechanisms for each. Local and military epidemiology are described, as are the specific actions taken by the US military for prevention and treatment purposes. Complications of such measures with regard to human health are also discussed, including possible chemical toxicities. Additionally, poor recognition of these diseases upon an individual's return leading to complications and treatment delays in the United States are examined. Information about canine leishmaniasis, poorly studied relative to its human manifestation, but of importance due to the utilization of dogs in military endeavors is presented. Future implications for the American healthcare system regarding malaria and leishmaniasis are also presented.