Vectors of Trypanosomatids (Kinetoplastida: Trypanosomatidae) in Tabatinga, Amazonas, Brazil

The sand flies transmit diseases to humans and animals, such as arboviruses and bartonellosis, besides the leishmaniasis. The objective of this research was identified potential vectors of this disease in the municipality of Tabatinga. Sand flies were captured with Miniature Light Trap and manual collection by aspiration at the bases of trees. In the months of August 2010 and 2011, were captured 4,542 sand flies (♂: 71.9% and ♀: 28.1%) vectors or suspected of trypanosomatids transmission, belonging to 13 species. The most abundant species was Lutzomyia umbratilis with 78.7%. A total of 576 (74,0%) sand flies of the genus Lutzomyia were dissected and natural infection by trypanosomatids was observed in 44 females. Blood in decomposition was detected at the digestive tract in 86.3% insects; being 59,0% of the ovaries in developing. The isoenzymatic analysis of ten isolates showed similar profiles to Leishmania colombiensis and Endotrypanum sp., however, the profile of the locus Malate Dehydrogenase (MDH) showed major similarity to the genus Endotrypanum. This is the first investigation of the fauna entomology and attempt of trypanosomatids isolation in the municipality of Tabatinga, area of triple border with Brazil

Antileishmanial activity of extracts from Libidibia ferrea : development of in vitro and in vivo tests

Treatment of cutaneous leishmaniasis (CL) is difficult due to the scarce number of drugs able to eliminate completely the intracellular form of the parasite. In the present study, the aim was to evaluate: i) phytochemical properties of extracts from Libidibia ferrea; ii) antileishmanial activity of extracts from L. ferrea against promastigotes and amastigotes of Leishmania (Leishmania) amazonensis and Leishmania (Viannia) guyanensis; iii) the effects of topical treatment using hydrogel containing active extract of L. ferrea on golden hamsters infected with L. (L.) amazonensis. Extracts from leaves, branches and fruits of L. ferrea were obtained with hexane and methanol and were tested by in vitro assays in promastigotes and murine macrophages J774 experimentally infected with amastigotes of Leishmania. Groups of hamsters with CL received topical treatment with a formulation of extract (10%) hydrogels, 50 mg. day(-1) for 40 days. In vitro activity of FrMeOH (methanolic extract from fruits without seeds) resulted in significant reduction of viable promastigotes of L. (L.) amazonensis (IC50 of 15.4 mu g. mL(-1)) and demonstrated inhibition potential of amastigote forms of L. (L.) amazonensis and L. (V.) guyanensis and low cytotoxicity in macrophages. The overall data of topical treatment with extract hydrogels (GelFrMeOH) showed that lesion sizes were significantly reduced (42.78%), with low parasite burden by RT-qPCR and culture analysis by microscopy examination, and with histopathological findings such as lower inflammatory cell infiltration 40 days after treatment. Chemical analysis demonstrated FrMeOH contains high levels of phenolic compounds. The results indicate a possible alternative therapy for CL using phytotherapics. KEYWORDS: cutaneous leishmaniasis, natural products, topical formulations, experimental treatmentPeer reviewe

Evaluation of different diagnostic methods of American Cutaneous Leishmaniasis in the Brazilian Amazon

Epidemiological studies have been conducted to better understand the dynamics of American Cutaneous Leishmaniasis (ACL) in the Amazon region where distinct species of Leishmania circulate. In endemic areas, the optimal diagnosis must be made in the earlier clinical presentation to avoid the complications of chronic disease. The scarcity of financial support, laboratory infrastructure and trained persons are the major obstacles in this reality. This paper describes the result of performing different diagnostic methods for ACL in Amazonas State between the years 2010 and 2011. The tests used were the intradermal skin test (Montenegro's skin test), ELISA (Enzyme-Linked Immunosorbent Assay), direct examination, culture isolation and identification of Leishmania species. A total of 38 suspected human cases of ACL were diagnosed by different methods, of which 71.0% (n = 27) were positive by direct examination, 75.6% (n = 28) had positivity in the culture isolates and, of these, 54.0% (n = 19) had infection with Leishmania (Viannia) guyanensis. The positivity of the intradermal skin test with the leishmanin solution was observed in 77.0% of cases analyzed and the serology with detection of IgG and IgM showed the presence of antibodies in 100% of exams realized results, showing variation in the titles of antibodies. The success of Leishmaniasis treatment depends on an effective and early diagnosis. Parasitological diagnosis is highly specific, but sensitivity is subject to variation because the tissue distribution of parasites generally is not homogeneous and depends on the specie of parasite. Moreover, parasitological tests require invasive procedures and depend on restrictive conditions for the collection of biological sample, which limit their use in large-scale for epidemiological studies. ELISA has been the most widely used serological method for the diagnosis of Visceral Leishmaniasis (VL) as it is easy to perform and has a low cost. However, flaws in specificity are observed in the diagnosis of cutaneous leishmaniasis. Actually the diagnosis needs to be done as an associated methods depending on the question to be solved. © 2016 Elsevier Inc

Nanoscaled hydrated antimony (V) oxide as a new approach to first-line antileishmanial drugs

Background: Coordination compounds of pentavalent antimony have been, and remain, the first-line drugs in leishmaniasis treatment for >70 years. Molecular forms of Sb (V) complexes are commercialized as sodium stibogluconate (Pentostam®) and meglumine antimoniate (MA) (Glucantime®). Ever-increasing drug resistance in the parasites limits the use of antimonials, due to the low drug concentrations being administered against high parasitic counts. Sb5+ toxicity provokes severe side effects during treatment. To enhance therapeutic potency and to increase Sb (V) concentration within the target cells, we decided to try a new active substance form, a hydrosol of Sb2O5·nH2O nanoparticles (NPs), instead of molecular drugs. Methodology/principal findings: Sb2O5·nH2O NPs were synthesized by controlled SbCl5 hydrolysis in a great excess of water. Sb2O5·nH2O phase formation was confirmed by X-ray diffraction. The surface of Sb (V) NPs was treated with ligands with a high affinity for target cell membrane receptors. The mean particle size determined by dynamic light scattering and transmission electron microscopy was ~35–45 nm. In vitro tests demonstrated a 2.5–3 times higher antiparasitic activity of Sb (V) nanohybrid hydrosols, when compared to MA solution. A similar comparison for in vivo treatment of experimental cutaneous leishmaniasis with Sb5+ nanohybrids showed a 1.75–1.85 times more effective decrease in the lesions. Microimages of tissue fragments confirmed the presence of NPs inside the cytoplasm of infected macrophages. Conclusion/significance: Sb2O5·nH2O hydrosols are proposed as a new form of treatment for cutaneous leishmaniasis caused by Leishmania amazonensis. The NPs penetrate directly into the affected cells, creating a high local concentration of the drug, a precondition to overcoming the parasite resistance to molecular forms of pentavalent antimonials. The nanohybrids are more effective at a lower dose, when compared to MA, the molecular drug. Our data suggest that the new form of treatment has the potential to reduce and simplify the course of cutaneous leishmaniasis treatment. At the same time, Sb2O5·nH2O hydrosols provide an opportunity to avoid toxic antimony (V) spreading throughout the body. © 2016 Franco et al

New human case reports of cutaneous leishmaniasis by Leishmania (Viannia) naiffi in the Amazon region, Brazil

ABSTRACT Few cases of human cutaneous leishmaniasis (CL) caused by Leishmania naiffi were described in the medical literature. The aim of this study was to report and analyze new cases of L. naiffi in the period between the years 1992 to 2011. The strains were characterized by isoenzyme analysis. All patients assisted had small lesions; ranging from 1.0x1.0 mm and 13.5x11.5 mm. The lesions observed were widely distributed: 55.5% on the lower limb, 5.5% in the abdominal area, 16.6% on upper limb and 22.2% in upper limb and back. Seventy-two percent of patients had ulcerated lesions. Clinical course of the disease varied from 1 to 10 months. According to gender, most infected individuals were men (83.3%). The patients came from Amazonas (10), Par

<strong>Uso da bioinformática na diferenciação molecular da <em>Entamoeba histolytica</em> e <em>Entamoeba díspar</em></strong> - DOI: 10.4025/actascihealthsci.v30i2.2375 <b>Molecular discrimination of <em>Entamoeba histolytica</em> and <em>Entamoeba dispar</em> by bioinformatics resources</b> - DOI: 10.4025/actascihealthsci.v30i2.2375

Amebíase invasiva, causada por <em>Entamoeba histolytica</em>, é microscopicamente indistinguível da espécie não-patogênica <em>Entamoeba dispar</em>. Com auxílio de ferramentas de bioinformática, objetivou-se diferenciar <em>Entamoeba histolytica</em> e <em>Entamoeba dispar</em> por técnicas moleculares. A análise foi realizada a partir do banco de dados da <em>National Center for Biotechnology Information</em>; pela pesquisa de similaridade de sequências, elegeu-se o gene da cisteína sintase. Um par de <em>primer</em> foi desenhado (programa <em>Web Primer</em>) e foi selecionada a enzima de restrição <em>TaqI</em> (programa <em>Web Cutter</em>). Após a atuação da enzima, o fragmento foi dividido em dois, um com 255 pb e outro com 554 pb, padrão característico da <em>E. histolytica</em>. Na ausência de corte, o fragmento apresentou o tamanho de 809 pb, referente à <em>E. dispar</em>.<br>Under microscopic conditions, the invasive <em>Entamoeba histolytica</em> is indistinguishable from the non-pathogenic species <em>Entamoeba dispar</em>. In this way, the present study was carried out to determine a molecular strategy for discriminating both species by the mechanisms of bioinformatics. The gene cysteine synthetase was considered for such a purpose by using the resources of the National Center for Biotechnology Information data bank in the search for similarities in the gene sequence. In this way, a primer pair was designed by the Web Primer program and the restriction enzyme TaqI was selected by the Web Cutter software program. The DNA fragment had a size of 809 bp before cutting, which is consistent with <em>E. dispar</em>. The gene fragment was partitioned in a first fragment with 255 bp and a second one with 554 bp, which is similar to the genetic characteristics of <em>E. histolytica</em>