Glycosomal Targets for Anti-Trypanosomatid Drug Discovery

Glycosomes are peroxisome-related organelles found in all kinetoplastid protists, including the human pathogenic species of the family Trypanosomatidae: Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. Glycosomes are unique in containing the majority of the glycolytic/gluconeogenic enzymes, but they also possess enzymes of several other important catabolic and anabolic pathways. The different metabolic processes are connected by shared co-factors and some metabolic intermediates, and their relative importance differs between the parasites or their distinct life-cycle stages, dependent on the environmental conditions encountered. By genetic or chemical means, a variety of glycosomal enzymes participating in different processes have been validated as drug targets. For several of these enzymes, as well as others that are likely crucial for proliferation, viability or virulence of the parasites, inhibitors have been obtained by different approaches such as compound libraries screening or design and synthesis. The efficacy and selectivity of some initially obtained inhibitors of parasite enzymes were further optimized by structure-activity relationship analysis, using available protein crystal structures. Several of the inhibitors cause growth inhibition of the clinically relevant stages of one or more parasitic trypanosomatid species and in some cases exert therapeutic effects in infected animals. The integrity of glycosomes and proper compartmentalization of at least several matrix enzymes is also crucial for the viability of the parasites. Therefore, proteins involved in the assembly of the organelles and transmembrane passage of substrates and products of glycosomal metabolism offer also promise as drug targets. Natural products with trypanocidal activity by affecting glycosomal integrity have been reported.

The semisynthetic landscape of aphidicolin: inspiration towards leishmanicidal compounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

New drugs with antiprotozoal activity from marine algae: a review

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Manifestações oculares na leishmaniose

The Canine Visceral Leishmaniasis is a chronic disease of endemic character, caused by Leishmania Chagasi in Americas. The inoculation of the promastigote form in the individual triggers a local and widespread immune reaction with formation of inflammatory infiltrates and deposition of immune complexes in tissues. Initial clinical symptoms of the disease are: weight reduction, hepatomegaly, splenomegaly and, according to the disease chronicity, signs such as alopecia, erythema, onychogryphosis, arthropathies, renal diseases, pyoderma, seborrheic dermatitis, muscle atrophy and Ocular diseases. Ocular diseases are often reported and are result of the direct parasitism or immune-mediated mechanisms caused by the disease. The Leishmania spp have greater affinity for the anterior segment, so that anterior uveitis is one of the most frequently diagnosed injuries. Blepharitis diffuse and Keratoconjunctivitis also appear as important ocular changes. In histological section, inflammatory infiltrates and macrophages with amastigote form are observed in all ocular tissues, with the exception of the retina and optical nerve. In the clinical analysis and disease diagnosis, should be considered the differential diagnosis, such as Ehrlichiosis and systemic hypertension, because these may cause some ocular manifestations similar to those observed in leishmaniasis

Leishmaniose visceral canina: estudo imagiológico em cães naturalmente infectados

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Relação entre carga parasitária de cães naturalmente acometidos por leishmaniose visceral e infectividade para Lutzomyia longipalpis: Lilian Aparecida Colebrusco Rodas. -

Pós-graduação em Ciência Animal - FMVA

Study on coinfecting vector-borne pathogens in dogs and ticks in Rio Grande do Norte, Brazil

Since dogs presenting several vector borne diseases can show none or nonspecific clinical signs depending on the phase of infection, the assessment of the particular agents involved is mandatory. The present study aimed to investigate the presence of Babesia spp., Ehrlichia spp., Anaplasma spp., Hepatozoon spp. and Leishmania spp. in blood samples and ticks, collected from two dogs from Rio Grande do Norte showing suggestive tick-borne disease by using molecular techniques. DNA of E. canis, H. canis and L. infantum were detected in blood samples and R. sanguineus ticks collected from dogs. Among all samples analyzed, two showed the presence of multiple infections with E. canis, H. canis and L. infantum chagasi. Here we highlighted the need for molecular differential diagnosis in dogs showing nonspecific clinical signs.

Genome-wide scan for visceral leishmaniasis in mixed-breed dogs identifies candidate genes involved in T helper cells and macrophage signaling

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação hepática de cães naturalmente infectados por leishmaniose visceral canina: aspectos ultrassonográficos modo B e Doppler

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Orientação sobre posse responsável em uma área endêmica para leishmaniose visceral canina

The purpose of this work was to provide guidance to householders in the responsible care of their pets, in a region where canine visceral leishmaniasis is endemic. Questionnaires on responsible ownership and the control of this disease were completed by owners of dogs and cats in the city of Araçatuba, São Paulo State, Brazil, in order to evaluate their level of knowledge. Based on the identified deficiencies, the project team provided the owners of the pets with individual guidance at home, focusing on the most critical issues. Concerning nutrition, 70.45% (62/88) of owners provided pet food only, 27.28% (24/88) administered a mixed diet, and 2.27% (2/88) provided homemade food. Additionally, 78.41% (69/88) did not permit the consumption of raw meat, rare meat, or bones. 9.09% (8/88) of owners allowed their pets to wander the neighborhood alone. Among dogs, 14.77% (13/88) had never been clinically tested by a qualified professional, and 6.82% (6/88) and 15.91% (14/88) had never received any kind of vaccine or vermifuge, respectively. In relation to population control, only 20.45% (18/88) of the dogs had been sterilized. It was also observed that 25% (22/88) of owners had already had canine visceral leishmaniasis seropositive dogs in their homes. 54.55% (12/22) of these owners had referred their pets to veterinary clinics for euthanasia, 22.73% (5/22) had used the services of the city’s animal disease control center, and 18.18% (4/22) had paid for private treatment. Nevertheless, 35.23% (31/88) of the dogs had never been submitted to tests for infection diagnosis. From the results obtained, it could be inferred that the individuals who participated in this study were poorly informed concerning basic pet care, demonstrating a need to implement community awareness campaigns for the responsible ownership of pets.

Avaliação do grau de conhecimento sobre Leishmaniose e Toxoplasmose em moradores do município de Araçatuba, SP

Considering the importance of zoonotic infections by Leishmania spp. and Toxoplasma gondii in Araçatuba region, São Paulo, this study determined the degree of knowledge of residents of Araçatuba about these two diseases. Questionnaires about these diseases were applied to 123 people. Regarding schooling, all the respondents were literate, and 69.9% (86/123) did not attend higher education and 30.8% (37/123) completed an undergraduate degree. Of these, 91.9% (34/37) knew the meaning of the term zoonosis, with significant difference compared to those who were not trained. This word was unknown by 57% (29/123) of total respondents. Most non-graduates, 59.3% (51/86) did not know what is toxoplasmosis and among graduates, 35.1% (13/37) ignored the subject.There were significant difference between these groups. Regarding the prevention of Leishmania infection, a greater proportion of the residents advocated environmental cleanup, the collar repellent and use of citronella. In relation to toxoplasmosis, 54.5% did not know the ways of transmission of this disease and among those with graduate degree, 13 ignoring any transmission medium. When it comes to prevention of this disease, 55.3% (68/123) did not know any prophylactic. In the group of higher education, 14 did not know how to prevent toxoplasmosis. The results of this study show that the majority of respondents are not aware about the mode of transmission of these diseases, especially in relation to toxoplasmosis.

Clinical and epidemiological aspects of feline leishmaniasis in Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Horizontal gene transfer confers fermentative metabolism in the respiratory-deficient plant trypanosomatid Phytomonas serpens

Among trypanosomatids, the genus Phytomonas is the only one specifically adapted to infect plants. These hosts provide a particular habitat with a plentiful supply of carbohydrates. Phytomonas sp. lacks a cytochrome-mediated respiratory chain and Krebs cycle, and ATP production relies predominantly on glycolysis. We have characterised the complete gene encoding a putative pyruvate/indolepyruvate decarboxylase (PDC/IPDC) (548 amino acids) of P. serpens, that displays high amino acid sequence similarity with phytobacteria and Leishmania enzymes. No orthologous PDC/IPDC genes were found in Trypanosoma cruzi or T. brucei. Conservation of the PDC/IPDC gene sequence was verified in 14 Phytomonas isolates. A phylogenetic analysis shows that Phytomonas protein is robustly monophyletic with Leishmania spp. and C. fasciculata enzymes. In the trees this clade appears as a sister group of indolepyruvate decarboxylases of gamma-proteobacteria. This supports the proposition that a horizontal gene transfer event from a donor phytobacteria to a recipient ancestral trypanosome has occurred prior to the separation between Phytomonas. Leishmania and Crithidia. We have measured the PDC activity in P. serpens cell extracts. The enzyme has a Km value for pyruvate of 1.4 mM. The acquisition of a PDC, a key enzyme in alcoholic fermentation, explains earlier observations that ethanol is one of the major end-products of glucose catabolism under aerobic and anaerobic conditions. This represents an alternative and necessary route to reoxidise part of the NADH produced in the highly demanding glycolytic pathway and highlights the importance of this type of event in metabolic adaptation. (C) 2012 Elsevier B.V. All rights reserved.

Caso alóctone de leishmaniose visceral canina, no município de Campo Mourão, Paraná, Brasil

O presente relato tem por objetivo descrever o primeiro caso alóctone de leishmaniose visceral (LV) no município de Campo Mourão, Paraná, Brasil, em um canino, da raça Boxer, apresentando lesões oculares e cutâneas, linfoadenomegalia e esplenomegalia, atendido no Hospital Veterinário da Faculdade Integrado de Campo Mourão, após ter residido na cidade de Campo Grande, Mato Grosso do Sul. O diagnóstico da enfermidade baseou-se na observação direta de formas amastigotas de Leishmania spp., em linfonodos poplíteos, sugerindo ser um caso de LV, uma vez que o animal era proveniente de área endêmica para a enfermidade. A migração de cães infectados de regiões endêmicas para áreas indenes torna-se um problema para a saúde pública, uma vez que poderá permitir a instalação de novos focos, favorecendo a disseminação da doença em todo o país.

Sandflies (Diptera, Psychodidae) from forest areas in Botucatu municipality, central western São Paulo State, Brazil

Abstract Background The study of the distribution and ecology of sandfly species is essential for epidemiological surveillance and estimation of the transmission risk of Leishmania spp. infection. Findings In the present study, sandflies were captured in native fragmented forest areas in Rubião Júnior district, Botucatu municipality, São Paulo state, Brazil, between September 2001 and January 2005. A minimum of two automatic light traps were installed per night from 6 pm to 8 am, in different months, resulting in approximately 900 collecting hours. During this period, 216 sandfly specimens of sixteen species were captured. Pintomyia monticola and Brumptomyia guimaraesi were the most abundant with 56 specimens (25.93%) captured per species, followed by Pintomyia fischeri 28 (12.96%) and Psathyromyia pascalei 18 (8.33%). Other captured species were Lutzomyia amarali, Sciopemyia sordellii, Psathyromyia aragaoi, Nyssomyia whitmani, Migonemyia migonei, Pintomyia bianchigalatiae, Pintomyia misionensis, Brumptomyia carvalheiroi, Brumptomyia cardosoi, Brumptomyia cunhai, Brumptomyia nitzulescui, Brumptomyia brumpti and Brumptomyia spp. represented by 58 (26.85%) specimens. Conclusions Although less frequently found, the presence of Pintomyia fischeri, Nyssomyia whitmani and Migonemyia migonei, known vectors of Leishmania braziliensis, indicates risk of American cutaneous leishmaniasis occurrence. Moreover, the absence of Lutzomyia longipalpis-the main vector of Leishmania infantum chagasi, which is the agent of American visceral leishmaniasis-suggests that there is no risk of introduction and establishment of this disease in the studied area.