Comparative studies of the anti-leishmanial activity of three Crotalus durissus ssp venoms

In this study, we compared the anti-leishmanial activity of three crotalic venoms (Crotalus durissus terrificus-Cdt, Crotalus durissus cascavella-Cdca, and Crotalus durissus collilineatus-Cdcol). Different concentrations of each venom incubated with Leishmania (Leishmania) amazonensis promastigotes were used. Cdt venom exhibited a higher anti-leishmanial activity (Inhibitory concentration-IC50-value of 4.70 +/- 1.72 mu g/ml) in comparison with that of Cdca venom (IC50 value of 9.41 +/- 1.21 mu g/ml), while Cdcol venom increased parasite numbers in 50% at a concentration of 44.30 +/- 2.18 mu g/ml. In addition, this venom showed a low anti-leishmanial activity in higher concentrations (IC50 value of 281.00 +/- 9.50 mu g/ml). The main fractions of Cdca venom were isolated and assayed under similar conditions used for assessing crude venom. The most active fractions were gyroxin and crotamine that had IC50 values of 3.80 +/- 0.52 mu g/ml and 19.95 +/- 4.21 mu g/ml, respectively. Convulxin also inhibited parasite growth rate, although this effect was not dose-dependent. Crotoxin was the least effective fraction with an IC50 value of 99.80 +/- 2.21 mu g/ml. None of the protein fractions presented cytotoxic effects against J774 cells in culture. In vivo assays using BALB/c mice revealed that crotoxin and crotamine were the main toxic fractions. In conclusion, C. durissus cascavella venom has three main fractions with anti-leishmanial activity. These results open new possibilities to find proteins that might be used as possible agents against cutaneous leishmaniasis.

Flebotomíneos (Diptera, Psychodidae) de área de cerrado no Município de Corumbataí, Centro-leste do Estado de São Paulo, Brasil.

Distribution and ecology knowledge of sandfly species is essential for epidemiology vigilance and risk determination for transmission of leishmaniasis. Sandfly trapping was carried out in a cerrado strictu sensu vegetation fragment in a rural area of Corumbataí Municipality, São Paulo State, Brazil, during July to November 2004. Two CDC light traps were used from 18h to 8h, once a month, resulting in 112 total hours of capture. During this period, 60 sandfly specimens of ten different species were sampled. The most abundant species and the one found in all captures was Pintomyia monticola totalizing 15 (25.0%) specimens, the second more abundant one was P. pessoai with 14 (23.3%) and the third one was Brumptomyia guimaraesi with 12 (20.0%) individuals collected. Other captured species were Psathyromyia aragaoi, B. avellari, B. brumpti, B. cunhai, P. bianchigalatiae, Evandromyia termitophila and Nyssomyia whitmani which corresponded to 19 (31.2%) specimens captured. Pintomyia pessoai and N. whitmani presence indicates transmission risk of American Cutaneous Leishmaniasis in the area.

Ocorrência de anticorpos contra Leishmania spp., Neospora caninum e Toxoplasma gondii em soros de cães atendidos no Hospital Veterinário da Universidade Estadual de Londrina-Pr

The aim of this study was to detect the presence of IgG antibodies anti-Leishmania spp., Toxoplasma gondii and Neospora caninum in dogs from a Veterinary Hospital from Universidade Estadual de Londrina. Blood samples from 112 animals were obtained by jugular venipuncture to obtain sera. The samples were tested by indirect immunofluorescence to detect antibodies anti-Leishmania spp., anti-N. caninum and anti-T. gondii. Thirteen (11.61%), 25 (22.32%), and 57 (50.89%) samples were positive for Leishmania spp., N. caninum, and T. gondii, respectively. The co-presence of anti-Leishmania spp. and N. caninum was observed in 6 (5.36%), anti-Leishmania spp. and anti-T. gondii in 8 (14.7%), and anti-N. caninum and anti-T. gondii in 18 (16.07%) samples. The co-presence of anti-Leishmania spp., anti-N. caninum and anti-T. gondii was observed in 5 (4.46%) dogs. There was a higher prevalence of Leishmania in Toxoplasma and Neospora positive animals, however, these results were not statistically significant (range p = 0.052 p = 0.06). The dogs have an important role in the epidemiological cycle of these diseases, which are important in animal and public health. The northern state of Paraná is an endemic area for human cutaneous leishmaniasis, therefore, studies should be conducted to uncover the real role of dogs as reservoirs of Leishmania to humans in the state.

Estudo soroepidemiológico de leishmaniose em equinos na região de Araçatuba-SP, Brasil, área endêmica para leishmaniose visceral

The aim of the present study was to perform a leishmaniasis survey in horses from Araçatuba, São Paulo, an endemic area of Brazil. Of the 466 horses tested for the presence of anti-Leishmania chagasi titers by ELISA, 68 (14.59%) were seropositive, with titers varying between 0.324 and 0.813. ELISA positive samples were also tested by immunocromatography and 19/466 (4.08%) were positive. The results of the present study indicated that equines are in contact and can attract phlebotomines, and highlight the necessity of a more accurate investigation on the role played by the horses living in endemic areas, in order to help to control the spread of the illness.

Identificação e análise de polimorfismos no gene que codifica a Lectina ligante de Manose (MBL) na espécie Canis lúpus familiaris

Pós-graduação em Biologia Geral e Aplicada - IBB

Necessidade de vigilância epidemiológica para Leishmania infantum (syn. Leishmania chagasi) e Leishmania (Viannia) braziliensis em flebotomíneos e gatos errantes no Bosque Municipal de Marília-SP

Pós-graduação em Medicina Veterinária - FMVZ

Visão geográfica integrada das estratégias de controle das leishmanioses no município de Teodoro Sampaio, SP, com o apoio do geoprocessamento

Pós-graduação em Geografia - FCT

Compostos de Pd(II) contendo ligantes piridinicos: potencialidades biologicas e aspectos estruturais

Pós-graduação em Química - IQ

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

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Síntese e avaliação biológica de bioisósteros de nitrofural ativos contra Leishmania amazonensis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Attraction of the sand fly Nyssomyia neivai (Diptera: Psychodidae) to chemical compounds in a wind tunnel

Background: Similar to other hematophagous insects, male and female sand flies must feed on plants to obtain sugar and, subsequently, energy to complete their life cycles. A large number of compounds emitted by plants may act as volatile signals to these insects. Primary alcohols have been detected in some plants, but in small amounts. In a previous report, the attractiveness of saturated primary alcohols with 7 to 9 carbons was evaluated for Lutzomyia longipalpis, the vector of American visceral leishmaniasis, with positive results.Methods: In the present study, a wide range of primary alcohols, 3 to 10 carbons, were tested to investigate their attractiveness to another sand fly species, Nyssomyia neivai, a putative vector of American cutaneous leishmaniasis. The mixture of compounds that induced the best sand fly response was also evaluated.Results: Of the eight compounds evaluated, hexanol and octanol elicited the best attractive responses for sand fly females.Conclusion: Phytochemicals may be an interesting source of search for new sand fly attractants.

Techniques to improve the maintenance of a laboratory colony of Nyssomyia neivai (Diptera: Psychodidae)

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

Influence of apoptosis on the cutaneous and peripheral lymph node inflammatory response in dogs with visceral leishmaniasis

In canine visceral leishmaniasis (CVL), the abnormalities most commonly observed in clinical examination on the animals are lymphadenomegaly and skin lesions. Dogs are the main domestic reservoir for the protozoon Leishmania (L.) chagasi and the skin is the main site of contamination by the vector insect. Some protozoa use apoptosis as an immunological escape mechanism. The aim of this study was to correlate the presence of apoptosis with the parasite load and with the inflammatory response in the skin and lymph nodes of dogs naturally infected with Leishmania (L.) chagasi. Thirty-three dogs from the municipality of Araçatuba (São Paulo, Brazil) were used, an endemic area for CVL. Muzzle, ear and abdominal skin and the popliteal, subscapular, iliac and mesenteric lymph nodes of symptomatic (S), oligosymptomatic (O) and asymptomatic (A) dogs were analyzed histologically. The parasite load and percentage apoptosis were evaluated using an immunohistochemical technique. Microscopically, the lymph nodes presented chronic lymphadenitis and the skin presented plasmacytic infiltrate and granulomatous foci in the superficial dermis, especially in the ear and muzzle regions. The inflammation was most severe in group S. The parasite load and apoptotic cell density were also greatest in this group. The cause of the lymphoid atrophy in these dogs was correlated with T lymphocyte apoptosis, thus leaving the dogs more susceptible to CVL. The peripheral lymph nodes presented the greatest inflammatory response. Independent of the clinical picture, the predominant inflammatory response was granulomatous and plasmacytic, both in the skin and in the peripheral lymph nodes. The ear skin presented the greatest intensity of inflammation and parasite load, followed by the muzzle skin, in group S. The ear skin area presented a non-significant difference in cell profile, with predominance of macrophages, and a significant difference from group A to groups O and S. It was seen that in these areas, there were high densities of parasites and cells undergoing apoptosis, in group S. The association between apoptosis and parasite load was not significant in the lymph nodes, but in the muzzle regions and at the ear tips, a positive correlation was seen between the parasite load and the density of cells undergoing apoptosis. The dogs in group S had the highest parasite load and the greatest number of apoptotic cells, thus suggesting that the parasite had an immune evasion mechanism, which could be proven statistically in the skin. © 2012 Elsevier B.V.

Lacrimal excretory system sequelae in patients treated for leishmaniasis

A leishmaniose pode destruir os tecidos nasais resultando em alterações da via lacrimal excretora. OBJETIVO: Avaliar a ocorrência de alterações do sistema lacrimal excretor em portadores de leishmaniose na fase de pós-tratamento. MÉTODOS: Foi realizada a avaliação da via lacrimal excretora em 45 portadores de leishmaniose tratada (90 vias lacrimais) pelo teste de Jones I. Treze pacientes (26 ductos nasolacrimais) tiveram o teste de Jones I alterado, tendo sido submetidos a dacriocistografia e endoscopia nasal. RESULTADOS: A maioria dos indivíduos avaliados apresentava a leishmaniose na forma cutânea (64,4%). Entretanto, 69,23% dos indivíduos com alteração do sistema lacrimal excretor apresentavam a forma mucocutânea antes do tratamento. A alteração mais freqüentemente detectada foi ducto nasolacrimal permeável e dilatado (92,30%). Apenas 3,84% (1/26) das vias lacrimais estavam obstruídas. A endoscopia nasal mostrou hipertrofia de corneto (53,84%), desvio de septo (53,84%) e perfuração do septo nasal (23,07%). CONCLUSÃO: em portadores de leishmaniose tratada encontra-se como seqüela mais freqüente no sistema excretor lacrimal as vias lacrimais permeáveis e dilatadas.

First Autochthonous Case of Canine Visceral Leishmaniasis in the Center of Rio Grande do Sul State, Brazil

Background: Leishmaniasis is one of the most important vector-borne diseases of humans. This parasitic disease can be caused by many species of Leishmania. In humans, different species of the parasite are associated with different forms of the disease, cutaneous and visceral. Among domesticated animals, dogs are the most important species in the epidemiology of this disease. Leishmania chagasi, an important zoonosis, is well established as the agent of visceral leishmaniasis in Brazil. The disease is endemic in north, northeast, midwest and southeast, and is transmitted to mammals by hematophagous insects such as the Lutzomyia longipalpis. In 2008, our research group has diagnosed a case of canine leishmaniasis in the municipality of Uruguaiana and subsequently there were several cases in the city and the neighbor municipality of Sao Borja. Most Brazilian states are endemic for leishmaniasis, with the exception of Rio Grande do Sul. In southern Brazil, the reports of humans and dogs infected by Leishmania spp. are the source of endemic area in the country. Therefore, the aim of this study is register the first clinical case of canine visceral leishmaniasis in the municipality of Santa Maria, RS.Case: In october 2010, a veterinary clinic of Santa Maria received a canine, female, Doberman, with two years of age. The animal had severe skin lesions on the head and limbs, pale mucous membranes, and enlarged lymph nodes. According to the owner, the animal showed progressive weight loss and anorexia for more than five days. During the clinical examination the blood was collected for hemogram and cytology of lymph nodes was performed by puncture aspiration with a fine needle. In the erythrogram, it was observed a decrease in the total number of erythrocytes (2.8 x 10(6)/mu L), hematocrit (21%), hemoglobin (6.8 g/dL) and platelets (98 x 10(3)/mu L). In the leucogram, any alteration was observed. The cytology of lymph nodes showed amastigotes forms, suggestive of the Leishmania spp. Based on this finding; we performed the blood collection for PCR, to confirm parasitism and to determine the species of Leishmania. At the molecular test was used PCR-specific for L. chagasi, and the result was positive.Discussion: This is the first autochthonous clinical case in the central region of the RS, non-endemic area for leishmaniasis. In serological studies of visceral leishmaniasis it was diagnosed in five asymptomatic dogs in the municipalities of Santa Maria, Julio de Castilhos and Itaara, however not confirmed by molecular analysis. In the municipalities of Cruz Alta and Uruguaiana cases of L. chagasi have been reported in dogs which previously resided in Leishmania sp. endemic areas. The municipality of Sao Borja had the first record of L. longipalpis in the RS during the leishmaniasis outbreak in 2008-2009. In the central region of the RS vector has not been found, but because in this first autochthonous case dog in Santa Maria believe that the parasite is present and/or doing other insect transmission of leishmaniasis. Clinical signs associated with hematologic and coagulation disorders observed in the canine are commonly described in symptomatic dogs in endemic regions. This case of autochthonous leishmaniasis reinforces the idea of the vector presence in Santa Maria, center of the RS. We believe that canine leishmaniasis is an emerging disease in the southern region of Brazil.