Leishmania Research Articles

New Insights into Pathogenesis and Immunity of Leishmania Parasites with Emphasis on Vaccines

New Insights into Pathogenesis and Immunity of Leishmania Parasites with Emphasis on Vaccines

Diferencias de género en la interacción entre consumo de tabaco y alcohol con la presión arterial elevada.

En diferentes regiones de Latinoamérica la infección por T. cruzi y Leishmania se superponen, por lo cual se reportan infecciones mixtas circulantes, debido a esto; deben realizarse pruebas diagnósticas específicas para evitar reacciones cruzadas entre estas dos patologías. Objetivo: Determinar patrones de fluorescencia que permitan la diferenciación entre Leishmaniasis, enfermedad de Chagas e infección mixta empleando epimastigotes de T. cruzi. Metodología: Se empleó la técnica de Inmunofluorescencia Indirecta utilizando epimastigotes de T. cruzi (TcV autóctono) como antígeno figurado frente a un panel de muestras de suero codificados como A, B, C y D correspondientes a pacientes con infección por: Leishmaniasis (A), Infección mixta por Leishmania y Chagas(B), Enfermedad de Chagas (C) y sin ninguna de las dos infecciones (D). Resultados: En los cuatro paneles de muestras se observaron diferentes patrones de intensidad de fluorescencia a nivel de membrana y núcleo de los epimastigotes de T. cruzi (TcV autóctono). Conclusiones: La técnica de Inmunofluorescencia (IFI) con antígenos de epimastigotes de T. cruzi a demostrado utilidad en la diferenciación entre enfermedad de Chagas, Leishmaniasis y/o infecciones mixtas por ambos parásitos en aquellas zonas donde la coexistencia de ambas es habitual.

Análise in silico de metabólitos ativos isolados de Libidibia ferrea Martius

O presente trabalho realizou estudos in silico para predição das atividades farmacocinéticas, físico-químicas, toxicológicas e biológicas de metabólitos isolados de Libidibia ferrea Martius, planta utilizada popularmente para o tratamento de inflamações e lesões, como antidiabética, antimicrobiana, antifúngica e antileishmaniose. As comparações foram realizadas através dos programas: chemsketch, mcule property calculator, preadmet, protox e pass online. Os resultados revelaram que apenas as moléculas lupenona e o trans-farnesol apresentaram absorção intestinal acima de 90%. Os metabólitos ácido gálico, catequina, metil-galato, quercetina e trans-farnesol seguem a regra de lipinsk em todos os seus parâmetros pré-condicionados. No que se refere a inibição enzimática, cada uma das moléculas do estudo demonstrou inibição direcionada a pelo menos duas enzimas da CYP. A lupenona foi a única molécula que se apresentou ativa contra o protozoário leishmania, além de ser promissora contra neoplasias e inflamação. A catequina e quercetina demonstraram resultados positivos no que tange a atividade antioxidante, e a maioria das substâncias do estudo em questão apresentaram capacidade de proteção mucomembranosa. Nenhuma substância demonstrou embriotoxicidade ou teratogênese, mas todas as moléculas demonstraram possuir certo nível de toxicidade em outros parâmetros de análise. Em termos farmacocinético, toxicológico e biológico, as moléculas pauferrol A, B e C foram as menos promissoras, enquanto que a lupenona, catequina e quercetina apresentaram os melhores resultados.

First record of Leishmania spp. in birds and bats from Sudan

First record of Leishmania spp. in birds and bats from Sudan

Molecular cloning and expression of hosphoenolpyruvate carboxykinase dominant epitope in Leishmania infantum

Objective Based on the (phosphoenolpyruvate carboxykinase, PEPCK) dominant epitopes gene of Leishmania infantum that has been analyzed and selected, we construct the corresponding recombinant prokaryotic expression vector to obtain the recombinant protein, construct the corresponding recombinant eukaryotic expression vector and verify the expression of eukaryotic vector in NIH3T3 cells, which laid the foundation for the subsequent vaccination and infection of animal experiment. Methods Based on the PEPCK dominant epitopes gene sequence, the recombinant prokaryotic and eukaryotic expression plasmid pET32a- PEPCK and pVAX1- EPEPCK were constructed by PCR reaction and enzyme reaction and were respectively transfected into E. coli and NIH3T3 cells of mice for expression. The expression of prokaryotic recombinant plasmid and the prokaryotic expressed protein purified by HisTrap affinity column were detected through SDS-PAGE and Western-Blot, and the expression of pVAX1-E PEPCK was verified by immunofluorescence. Results The correct sequencing results of the recombinant prokaryotic and eukaryotic vectors showed that the construction of recombinant vectors was successful. The positive results of 48.08 kD of recombinant protein were detected in SDS-PAGE and Western Blot, and immunofluorescence results of NIH3T3 cells transfected with eukaryotic recombinant vectors showed positive results. Conclusion We successfully constructed the recombinant prokaryotic and eukaryotic expression vectors: pET32a- PEPCK and pVAX1-E PEPCK , successfully got the recombinant proteins that followed by proteinic purification and confirmed the expression of pVAX1-E PEPCK in NIH3T3 cells, which is the basis for experiments where animals are vaccinated with a DNA prime-protein boost vaccines. 摘要：目的 基于前期分析并选取的婴儿利什曼原虫 PEPCK 的优势表位基因, 构建相应重组原核表达载体以获得 重组蛋白, 构建相应重组真核表达载体并验证真核载体在 NIH3T3 细胞中的表达, 为后续动物的免疫和感染实验备下 基础。 方法 根据 PEPCK 优势表位基因序列, 经 PCR 反应及酶切连接构建重组原核与真核表达质粒 pET32a- PEPCK 和 pVAX1-E PEPCK 并分别转染至 E. coli 和 NIH3T3 细胞中进行表达。采用 SDS-PAGE 电泳和 Western Blot 鉴定原核重 组质粒在大肠杆菌中的表达和原核表达蛋白被镍柱纯化后的情况, 采用免疫荧光实验验证真核重组质粒在细胞中的 表达。 结果 重组原核与真核载体的正确测序结果表明重组载体构建成功。SDS-PAGE 电泳和 Western Blot 的结果 显示, 大肠杆菌中表达的原核重组蛋白以及纯化后的蛋白在 48.08 kD 处存在条带, 转染了真核重组载体的 NIH3T3 细胞 的免疫荧光结果呈阳性。 结论 成功构建了 PEPCK 优势表位基因的重组原核和真核表达载体: pET32a- PEPCK 和 pVAX1-E PEPCK , 成功表达相应的重组蛋白并纯化并验证了 pVAX1-E PEPCK 在 NIH3T3 细胞中的表达, 为后续 DNA 疫苗初次免疫和蛋白疫苗加强免疫的动物实验备下基础。

Vorinostat as potential antiparasitic drug.

Vorinostat is a drug used to treat cutaneous T cell lymphoma whose action mechanism is based on Histone Deacetylase inhibition. Histone Deacetylases are a family of enzymes that remove acetyl groups from histone and non-histone proteins that control many crucial processes, such as gene regulation, cell cycle progression, differentiation, and apoptosis. Histone Deacetylase homologues are also expressed in parasites of the genus Plasmodium, Leishmania, Cryptosporidium, Schistosoma, Entamoeba, and others. In this way, antiparasitic properties of Vorinostat have been explored. The aim of this review is to report the current state knowledge of Vorinostat as antiparasitic drug against Plasmodium, Leishmania, Cryptosporidium, Schistosoma and Entamoeba in order to support future investigation in this field. The authors revised the recent and relevant literature concerning the topic and discussed advances and limitations of studies on Vorinostat as potential drug to treat human parasitic diseases. Vorinostat has been efficient in vitro and, in some cases, in vivo, against parasites that cause parasitic diseases, such as malaria, leishmaniasis, cryptosporidiosis, amoebiasis, and schistosomiasis. In vitro and in vivo models have demonstrated the antiparasitic activity of Vorinostat, however, the challenge is to assay its activity in animal models and to evaluate if Vorinostat is safe for humans as new alternative to treat human parasitic infections.

Trypanocidal potentialities of skimmianine an alkaloid isolated from Zanthoxylum pistaciifolium griseb leaves

Background: Zanthoxylum pistaciifolium Griseb (Rutaceae) is an endemic Cuban species traditionally used for respiratory ailment treatments and religious practices. Objective: The aim of this study was to evaluate the in vitro antimicrobial activity from Z. pistaciifolium leaves. Materials and Methods: Four phases obtained from the ethanolic extract were tested against bacteria (Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa), fungi (six Candida spp.) and parasites (Leishmania amazonensis and Trypanosoma cruzi) by microdilution methods. In addition, the cytotoxicity was determined against peritoneal macrophages from BALB/c mice and fibroblast cells L929 using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and resazurin assay. Results: The hexane-butanone phase was the most active against Candida spp. and exhibited moderate effect on T. cruzi trypomastigote (39.3 ± 5.5 μg/mL). The skimmianine isolated from this phase and characterized by nuclear magnetic resonance showed a median inhibitory concentration of 58.0 ± 4.0 μg/mL against T. cruzi trypomastigotes and 31.2% ± 6.5% of inhibition on amastigote form at 100 μg/mL. Antiprotozoal activity of this alkaloid was selective with a selectivity index of 9. Conclusion: The current study demonstrated for the first time the antimicrobial potential of the leaves of Z. pistaciifolium, supporting its ethnobotanical uses. The trypanocidal activity observed for the alkaloid skimmianine could contribute to development future of an herbal medicine for the treatment of Chagas diseases.

Serological and clinical survey of Canine Leishmaniasis in Southwestern Region of Kosovo.

Canine Leishmaniasis caused by Leishmania infantum is endemic in Mediterranean countries. The disease represents an important public health issue in Kosovo in which the autochthonous cases by humans were reported in the last years. The objective of this study was to survey the serological and clinical data of Canine Leishmaniasis in dogs in southwestern region of Kosovo. The blood samples were collected from stray dogs in four municipalities, respectively Prizren, Gjakova, Rahovec and Deçan. The total 125 samples were collected between April/September 2016. Antibodies of Leishmania infantum were detected by competitive enzyme-linked immunosorbent assay (ELISA IgG). Out of total 125 serum samples, 23 dogs (18.4%) were positive for Leishmania infantum. In three of 23 infected dogs (13%) were shown the clinical signs of Canine Leishmaniasis as skin and ocular lesions, decreased appetite, lameness, diarrhea, lethargy and progressive weight loss. The highest infection rate was detected in Prizren municipality (21.6%), followed by Gjakova (17.6%), Rahovec (17.1%) and Deçan (7.8%). The present study confirmed that the Leishmaniasis is endemic in southwestern part of Kosovo and emphasized the need to establish the surveillance and control of this disease.

Component community of helminth parasites in black cuskeel Genypterus maculatus (Tschudi, 1846) from north Peru.

In Peru, only 12.7% (n=207) of fish species have had some record as parasitic metazoan hosts. The objective of this investigation was to determine the community of helminth parasites in black cusk-eel Genypterus maculatus (Tschudi, 1846) of north Peru. Fifty specimens of G. maculatus from Puerto Pimentel, province of Chiclayo, department of Lambayeque, Peru were evaluated. For the analysis of the parasitic community, the parasitological ecological indexes of prevalence (P), mean abundance (MA), mean intensity (MI) of infection, the dispersion indices, the correlation between total length (TL) and sex of fish vs parasitological ecological indexes, were calculated. The component community of the parasitic helminths in the evaluated fish was dominated by the presence of endoparasitic flatworms and absence of ectoparasites. The parasitic fauna of G. maculatus included eight endoparasitic species, four trematodes, two cestodes, one acanthocephalan and one nematode species. The species with the highest prevalence and abundance were Helicometra fasciata (Rudolphi, 1819), Scolex pleuronectis Müller, 1788 and Corynosoma australe Johnston, 1937. The prevalence of infection of C. australe was found positively related to the total length of G. maculatus. The sex of G. maculatus was not found associated with the P, MA and MI of any of the helminth parasites. This is the first study of ecological aspect in the parasitic fauna of G. maculatus made in Peru.

Alarming: high prevalence of Leishmania infantum infection in cats from southern Iran based on molecular and serological methods.

Recently, Leishmania infantum has increasingly been detected in stray cats in endemic regions of the world. Cats have been considered playing a role in the epidemiology of visceral leishmaniosis, an endemic zoonosis in Iran. The studies concerning feline leishmaniosis (FeL) allow the hypothesis that cats can be considered as potential reservoirs. The investigations on Leishmania infection in cats are very few in Iran and therefore we aimed to assess the L. infantum infection in stray cats and its possible role in transmission of the disease to human by direct agglutination test (DAT), ELISA, nested-PCR and confirmation via sequencing and phylogenetic analysis in Fars province, Iran. Whole blood samples were obtained from 174 stray cats. Anti-Leishmania antibodies were detected in the sera using DAT and ELISA. DNA was extracted from the buffy coat of each subject and PCR amplified, targeting Leishmania kDNA gene. PCR results were confirmed by sequence analysis. Prevalence of clinical signs in positive cats was 19.0%. Anti-Leishmania antibodies with different titers were detected in 48 (27.59%) and leishmanial DNA in 36 (20.69%) of the cats. The sequencing of PCR-positive cats revealed the parasite as L. infantum. A high seroprevalence of L. infantum was revealed, with higher levels in males, adult cats, and those living in rural districts and southern zones. Despite the reservoir task of cats in nature is still ambiguous, the high serological and molecular detection of L. infantum in stray cats indicates that cats are regularly bitten by infected sand flies in Fars province, southern Iran, and may have a potential reservoir role in the maintenance of L. infantum in the endemic areas of zoonotic visceral leishmaniosis in Iran. Anyway, Leishmania infection must be appraised in the differential diagnosis of cutaneous or systemic clinical signs in cats.

Serological study of Leishmania infantum in dogs from Western Uganda

La Leishmaniosis visceral humana causada por Leishmania donovani es una enfermedad antroponotica endemica en muchos paises de Africa oriental. Sin embargo, se desconoce si animales domesticos o salvajes pueden tener un papel en esta infeccion. El principal objetivo de este estudio fue detectar anticuerpos frente a Leishmania infantum en sueros de perros del noroeste de Uganda mediante ELISA indirecto y evaluar los factores de riesgo. Para ello, se analizaron muestras de suero del ano 2017 y muestras de suero impregnadas en papel de filtro Whatman no3 del 2018. El trabajo de campo se llevo a cabo en los Parques Nacionales de Elizabeth Queen (QENP), Mgahinga, Budongo y en los distritos de Kasese, Kapchorwa, Buliisa, Masindi, Kibingo, Hoima y Kanungu. Las muestras de suero del 2017 fueron todas negativas. La seroprevalencia global obtenida de las muestras impregnadas en papel filtro fue del 50.8%, siendo los distritos de Karusandara y Kilembe los que obtuvieron una mayor proporcion de perros seropositivos. Entre los datos de frecuencia analizados, no se encontro ninguna asociacion estadisticamente significativa entre las variables estudiadas. Si bien, se observaron valores estadisticamente significativos con respecto a porcentajes de positividad registrados por localidad y condicion corporal de los perros muestreados. Los resultados del presente estudio sugieren el posible caracter endemico de la leishmaniosis canina en el noreste de Uganda. No obstante, estudios futuros son necesarios para determinar la prevalencia real de esta infeccion y su correacion con otras tripanosomiasis en todo el pais y evaluar el verdadero rol de los perros como reservorios a la leishmaniosis en esta area geografica.

Diketopiperazine alkaloids produced by the endophytic fungus Penicillium citrinum and evaluation of their antileishmanial activity

Chromatographic fractionation of the antileishmanial extract obtained from fermentation of the endophytic fungus Penicillium citrinum, isolated from leaves of Ageratum myriadenia, yielded three diketopiperazine alkaloids; cyclo(L-Pro-L-Leu) (1), cyclo-(L-Pro-L-Phe) (2) and tryprostatin B (3). The structures of these compounds were established on the basis of spectroscopic methods and comparison with the literature. Compounds 1 and 2 were active against both amastigote-like forms of Leishmania (Leishmania) amazonensis and intracelular amastigotes of L. (Leishmania) infantum with approximately 50% of parasite growth inhibition at 100 μM. None of the compounds were considered toxic against human leukemia monocyte cell line (THP-1) at 100 μM. It is the first report about isolation of these diketopiperazines from P. citrinum and their antileishmanial potential against L. (L.) infantum. Key words: Microfungi, natural products, in vitro, Leishmania, amphotericin B, cytotoxic activity.

Identification of putative transcription factors explain Leishmania spp. disease types

Identification of putative transcription factors explain Leishmania spp. disease types

A Study to Assess the Safety, Efficacy and Immunogenicity of Leishmania Vaccine ChAd63-KH in PKDL

A Study to Assess the Safety, Efficacy and Immunogenicity of Leishmania Vaccine ChAd63-KH in PKDL

In vitro antileishmanial activity of methanolic extracts for some selected medicinal plants

Objective: The aim of this study is to evaluate the antileishmanial activity of selected medicinal plants; ten well-known medicinal plants cultivated and growing under African environmental conditions were studied. Materials and Methods: The methanolic extracts of these plants were screened for their antileishmanial activity against Leishmania major using 3-(4.5-dimethylthiazol-2yl)-2.5-diphenyltetrazolium bromide assay. Results: The methanol extract of Colchicum autumnale and Alpinia officinarum showed potent antileishmanial activity at inhibition% value of 98.29% ± 0.75% and 97.25 ± 1.63%, respectively, while Silybum marianum exhibited inhibition% value of 90.97% ± 1.13%, compared with the standard amphotericin B (89.31% ± 2.08%). Conclusion: Considering these results, medicinal plants from African environment could constitute a developer source for antileishmanial compounds.

Crystal Structure of Histidine Triad Nucleotide-Binding Protein from the Pathogenic Fungus Candida albicans.

Histidine triad nucleotide-binding protein (HINT) is a member of the histidine triad (HIT) superfamily, which has hydrolase activity owing to a histidine triad motif. The HIT superfamily can be divided to five classes with functions in galactose metabolism, DNA repair, and tumor suppression. HINTs are highly conserved from archaea to humans and function as tumor suppressors, translation regulators, and neuropathy inhibitors. Although the structures of HINT proteins from various species have been reported, limited structural information is available for fungal species. Here, to elucidate the structural features and functional diversity of HINTs, we determined the crystal structure of HINT from the pathogenic fungus Candida albicans (CaHINT) in complex with zinc ions at a resolution of 2.5 Å. Based on structural comparisons, the monomer of CaHINT overlaid best with HINT protein from the protozoal species Leishmania major. Additionally, structural comparisons with human HINT revealed an additional helix at the C-terminus of CaHINT. Interestingly, the extended C-terminal helix interacted with the N-terminal loop (α1–β1) and with the α3 helix, which appeared to stabilize the dimerization of CaHINT. In the C-terminal region, structural and sequence comparisons showed strong relationships among 19 diverse species from archea to humans, suggesting early separation in the course of evolution. Further studies are required to address the functional significance of variations in the C-terminal region. This structural analysis of CaHINT provided important insights into the molecular aspects of evolution within the HIT superfamily.

New Physical Approaches combined with nanoparticles in Leishmania major Treatment

Introduction: Cutaneous leishmaniasis is a mutual parasitic disease, which is endemic in some countries of the world. The use of common drugs has been restricted because of confirmed side effects and drug resistance. There are still serious challenges in the treatment of CL. Developing new therapeutic methods for leishmaniasis, besides obtaining a prompt treatment response that prevents lesions' progression and scarring, is a significant success in the treatment of the disease. Novel approaches such as nanotechnology have been applied as a therapeutic modality. This study aimed at evaluating the influence of three physical approaches combined with nanoparticles on promastigotes, amastigotes, and lesion-induced parasites. Materials and Methods: Leishmania promastigotes were treated with gold nanoparticles combined with different duration of the microwave with 2450 MHz frequency. So, the promastigotes treated with electroporation and ultraviolet irradiation in presence of silver and titanium dioxide nanoparticles respectively. Leishmania amastigotes were preserved by GNP and SNP with different conditions exposure of Microwave irradiation and electroporation. Ultraviolet irradiation in presence of silver nanoparticles used to reduce the size of lesion-induced parasites. Results: Promastigotes survival rate induced a significant decline in different conditions of all three approaches in the presence of nanoparticles in comparison to similar samples without there. The least survival of amastigotes was also recorded in the groups containing nanoparticles received the microwave and electroporation. In addition, the findings on parasite burden and size of lesions showed a significant difference between the treatment groups with SNPs and UV irradiation and control group. Conclusion: The finding emphasized to the utility of new approaches by nanotechnology could be useful for the treatment of cutaneous disease such as leishmaniasis. For validation of this statement need to more research and some studies have been planned for this aim.

Evidence Based Insights on Leishmania Replication and Cytokinesis

Evidence Based Insights on Leishmania Replication and Cytokinesis

A Review of effectual factors in the Pathogenesis of Leishmania Parasites

A Review of effectual factors in the Pathogenesis of Leishmania Parasites

TREATMENT OUTCOME AND DETERMINANTS AMONG PATIENTS WITH VISCERAL LEISHMANIASIS IN ARBA MINCH GENERAL HOSPITAL LEISHMANIASIS RESEARCH AND TREATMENT CENTER, GAMO GOFA ZONE, SNNPR, ETHIOPIA

- Introduction: Visceral Leishmania represents a challenging diagnosis and treatment because the clinical picture of Visceral Leishmaniasis, so that the treatment outcome is compromised with many factors, thus study try to asses real picture of treatment outcome with determinants. Objective: To assess treatment outcome and determinant factors among patient with visceral Leishmaniasis in Arba Minch General Hospital Leishmania Research and Treatment Center. Methods: Institution-based, Cross-sectional, retrospective study was conducted among Leishmaniasis patients in Arba Minch general hospital. Patient charts that have been treated from January 2011-December 2015 were reviewed. A total of 348 charts were selected by Simple Random Sampling technique and included in the study. The data were entered and cleaned using Epi-info version 7.0 and analysis was carried out using SPSS-20 statistical packages. Multi-variate logistic regression analysis was carried out to identify the independent predictors of treatment outcome. Result: A total of 348 patient's charts were included in the study. The prevalence of poor outcome was found to be 8.6%. The presence of bleeding/Epsitaxis[AOR=5;95% CI:1.3,19.3], tuberculosis[AOR=3.7;95%CI:1.83,6.3], septic syndrome[AOR=4.3;95% CI: 6.1,32], and adverse drug side effect[AOR=4.5;95%CI:2.73,13.6] were the independent predictors of treatment outcome. Conclusion and recommendation: The prevalence of poor treatment outcome among patients with VL in the study area is high. Concomitant infection; bleeding/Epsitaxis, tuberculosis, septic syndrome and adverse side effect were independently associated with poor treatment outcome. The clinical management of VL in co-infected patients is a major challenge that requires new treatment approaches to improve its outcome.