Leishmaniasis OR Leishmania

Leishmaniasis is one of the most significant of the neglected tropical diseases, with 350 million people in 98 countries worldwide living at risk of developing one of the many forms of the disease. During the transmission of the parasite from its vector to the vertebrate host, neutrophils are rapidly recruited to the site of the sandfly bite. Using different strategies, neutrophils can often kill a large number of parasites. However, some parasites can resist neutrophil-killing mechanisms and survive until macrophage arrival at the infection site...

In Brazil, the visceral leishmaniasis (VL) is caused by Leishmania infantum, while the tegumentary leishmaniasis (TL) etiological agents are mainly Leishmania braziliensis and Leishmania amazonensis. The canine visceral leishmaniasis (CVL) diagnosis is an important step of the VL control program in Brazil, which involves the elimination of infected dogs, the main urban VL reservoirs. The current serology-based diagnostic tests have shown cross-reactivity between these three species, whereas molecular diagnosis allows high sensitivity and specie identification...

The objective of the present study was to compare the host's immune responses between unresponsive and responsive patients with anthroponotic cutaneous leishmaniasis (ACL) treated by meglumine antimoniate. A case-control study was carried out in an endemic focus in Iran. Blood samples were taken from patients and peripheral blood mononuclear cells (PBMCs) were isolated. Two wells were considered for each isolate of unresponsive and responsive patients; one was exposed to L. tropica (Lt-stimulated cells) and the other remained non-exposed (non-stimulated cells)...

BACKGROUND: The Mediterranean area is endemic for the zoonotic form of visceral leishmaniasis (VL) caused by Leishmania infantum, a species which has been recently associated with unexpected epidemiological and clinical features. METHOD: We report the result of a systematic review of the literature on VL unusually presenting with spleen focal lesions, including three previously unpublished cases. RESULTS: A total of 28 cases of VL with multiple spleen focal lesions were retrieved...

For years, mammals of the order Pilosa have been considered Leishmania reservoirs. But while most studies have focused on sloth species, anteaters have been overlooked, and in many Leishmania endemic countries like Mexico, no studies have been carried out. The aims of this work were to identify the presence of Leishmania spp. in tissue samples from road-killed northern tamanduas (Tamandua mexicana), using PCR amplification and sequencing of ITS1 DNA, and to discuss the role of Pilosa mammals as reservoirs of Leishmania based on available scientific records...

The resistance mechanisms of bacteria and protozoans have evidenced the need of discover new compounds with potential pharmaceutical activity against pathogenic microorganisms. Medicinal plants have been for centuries a promising alternative as sources of new drugs. The objective of this work was to evaluate the chemical composition, antimicrobial and antileishmanial activities of Cinnamomum zeylanicum , Origanum vulgare , and Curcuma longa essential oils. Chemical analysis was performed by gas chromatography-mass spectrometry...

A 27-year-old man presented with high-grade intermittent fever for 4 months, generalised fatigue for 2 months, intermittent gum bleeds for 1 month and loss of weight of 15 kg. He appeared cachectic with generalised wasting, had pallor and features of reticuloendothelial system proliferation. His liver span was 17 cm. He had massive splenomegaly. His cardiovascular, respiratory and neurological examination were normal. He was diagnosed to have visceral leishmaniasis (VL) based on bone marrow (BM) examination that showed Leishmania donovani (LD) bodies and was treated with liposomal amphotericin (LA)...

BACKGROUND: Visceral leishmaniasis is a neglected parasitic disease with no vaccine available and its pharmacological treatment is reduced to a limited number of unsafe drugs. The scarce readiness of new antileishmanial drugs is even more alarming when relapses appear or the occurrence of hard-to-treat resistant strains is detected. In addition, there is a gap between the initial and late stages of drug development, which greatly delays the selection of leads for subsequent studies. METHODOLOGY/PRINCIPAL FINDINGS: In order to address these issues, we have generated a red-shifted luminescent Leishmania infantum strain that enables long-term monitoring of parasite burden in individual animals with an in vivo limit of detection of 106 intracellular amastigotes 48 h postinfection...

We analyzed the association between insulin-like growth factor-I (IGF-I) and the pathogenesis of anemia during active visceral leishmaniasis (VL). Serum levels of IGF-I, IGF-binding protein 3 (IGFBP3), and cytokines were measured in samples from individuals with active VL and cured VL, asymptomatic Leishmania -infected, and noninfected individuals. Then, we extended our analysis to VL dogs to evaluate hematimetric parameters, bone marrow alterations, and cytokine and IGF-I expression. We identified a positive correlation between lower IGF-I and IGFBP3 levels in active VL patients and lower hemoglobin levels...

Background/aim: Thiol-specific antioxidant (TSA) protein is one of the most promising molecules among candidates for vaccine against cutaneous leishmaniasis. It was found to be significantly protective against different Leishmania species. In this study, cloning and molecular characterization of thiol-specific antioxidant gene of L. tropica Turkey isolate (LtTSA) were aimed. Materials and methods: LtTSA was amplified by PCR using the specific primers of TSA gene and cloned into the pcDNA3...

Visceral Leishmaniasis is a deadly disease caused by Leishmania infantum, endemic in more than 98 countries across the globe. Although the most common means of transmission is via a sand fly vector, there is growing evidence that vertical transmission may be critical for maintaining L. infantum infection within the reservoir, canine, population. Vertical transmission is also an important cause of infant morbidity and mortality particularly in sub-Saharan Africa. While vertical transmission of visceralizing species of Leishmania has been reported around the globe, risk factors associated with this unique means of Leishmania transmission have not been identified therefore interventions regarding this means of transmission have been virtually non-existent...

Worldwide, an estimated 12 million people are infected with Leishmania spp. and an additional 350 million are at risk of infection. Leishmania are intracellular parasites that cause disease by suppressing macrophage microbicidal responses. Infection can remain asymptomatic or lead to a spectrum of diseases including cutaneous, mucocutaneous, and visceral leishmaniasis. Ultimately, the combination of both pathogen and host factors determines the outcome of infection. Leishmaniasis, as well as numerous other infectious diseases, exhibits sex-related differences that cannot be explained solely in terms of environmental exposure or healthcare access...

The study aims to evaluate the antiprotozoal activities of 20 plant metabolites on Trypanosoma cruzi and Leishmania amazonensis amastigotes. Compounds 1-20 were obtained and identified by using chromatographic and spectroscopic techniques. The antiparasitic assays were performed on the intracellular form of T. cruzi and L. amazonensis using human leukaemic THP-1 cells as the host. The mechanism of action of the most active compounds was explored in silico by molecular docking using T. cruzi trypanothione reductase (TR) as a target, whereas the in vitro studies were performed by enzymatic assay using T...

Visceral leishmaniasis (VL) was firstly reported in Armenia in 1913. Following a considerable increase of the number of cases until the mid 1950s, the disease disappeared after 1969 and re-emerged in 1999. Scientific literature about VL in Armenia is available only in Russian or Armenian. This paper presents a historical overview about leishmaniasis in Armenia based on this literature as well as an epidemiological update since the re-emergence of the disease. In 1999-2016, 116 indigenous VL cases were recorded mainly in children in 8 of the 11 districts, however, VL is underreported because of lack of trained medical personal and diagnostic facilities...

Cutaneous leishmaniasis (CL) is a zoonotic infectious disease caused mainly by Leishmania infantum Nicolle, 1908 (Kinetoplastida: Trypanosomatida) transmitted by dominant species Phlebotomus tobbi Adler & Theodor (Diptera: Psychodidae) in Adana, Turkey. CL has been reported to be detected commonly in low-socioeconomic status population scattered in rural areas. The environmental determinants are relatively poorly understood, especially in Adana despite the fact that Adana is endemic foci of CL. The subject of this study was the current and future probability model of P...

Determination of the residual activity of insecticides is an essential component in the selection of an appropriate insecticide for indoor residual spraying operations. This report presents the results of a laboratory study to evaluate the residual bio-efficacy of four insecticides sprayed on the most common house-wall surfaces that occur in Egypt (wood, mud, and cement) against Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae) and Culex pipiens Linnaeus, 1758 (Diptera: Culicidae). In total, 28,050 P...

Leishmania (Leishmania) amazonensis has adaptive mechanisms to the host environment that are guided by its proteinases, including cysteine proteinase B (CPB), and primarily its COOH-terminal region (Cyspep). This work aimed to track the fate of Cyspep by surface plasmon resonance (SPR) of promastigotes and amastigotes to gain a greater understanding of the adaptation of this parasite in both hosts. This strategy consisted of antibody immobilization on a COOH1 surface, followed by interaction with parasite proteins and epoxysuccinyl-L-leucylamido(4-guanidino)butane (E-64)...

We present here the first draft genome sequence of Leishmania (Viannia) lainsoni strain 216-34, sequenced using PacBio and MiSeq platforms. PacBio contigs were generated from de novo assemblies using CANU version 1.6 and polished using Illumina reads.

We report new organoselenium compounds bearing the sulfonamide moiety as effective inhibitors of the β-isoform of Carbonic Anhydrase from the unicellular parasitic protozoan L. donovani chagasi. All derivatives were evaluated in vitro for their leishmanicidal activities against Leishmania infantum amastigotes along with their cytotoxicities in human THP-1 cells. Compounds 3e-g showed their activity in the low micromolar range with IC50 values spanning from 0.72 to 0.81 µM and selectivity indexes (SI) > 8 (for 3g SI > 30), thus much higher than those observed for the reference drugs miltefosine and edelfosine...

BACKGROUND: Miltefosine (MF) is the only oral drug available for treatment of visceral leishmaniasis (VL) and post-kala-azar dermal leishmaniasis (PKDL). Although the drug is effective and well tolerated in treatment of VL, the efficacy and safety of MF for longer treatment durations (>28 days) in PKDL remains unclear. This study provides an overview of the current knowledge about safety and efficacy of long treatment courses with MF in PKDL, as a strategy in the VL elimination in South Asia...