Phlebotomine (Diptera: Psychodidae) survey and some considerations about epidemiological aspects of canine leishmaniasis in Rio Claro city, São Paulo, Brazil.

Between 2000 and 2004, 170 sand flies were captured in urban or peri-urban areas of the Rio Claro city, SP, Brazil. Nyssomyia neivai, the main LTA vector species in São Paulo territory, corresponded to 124 specimens (72,94%) of the total number of captured insects. Incidence of American Cutaneous (LTA) and Visceral leishmaniasis (LVA) is increasing in human and dogs in São Paulo State. Rio Claro city is located in the center-east region of the State. During 2001 and 2003, two cases of alochtonus canine LVA and an autochthonous case of canine LTA were locally diagnosed. Results indicate the risk of LVA establishment in this region. Possible role of alternative vectors in leishmaniasis transmission is discussed.

Nitric oxide and brazilian propolis combined accelerates tissue repair by modulating cell migration, cytokine production and collagen deposition in experimental leishmaniasis

The fact that drugs currently used in the treatment of Leishmania are highly toxic and associated with acquired resistance has promoted the search for new therapies for treating American tegumentary leishmaniasis (ATL). In this study, BALB/c mice were injected in the hind paw with Leishmania (Leishmania) amazonensis and subsequently treated with a combination of nitric oxide (NO) donor (cis-[Ru(bpy)(2)imN(NO)](PF6)(3)) (Ru-NO), given by intraperitoneal injection, and oral Brazilian propolis for 30 days. Ru-NO reached the center of the lesion and increased the NO level in the injured hind paw without lesion exacerbation. Histological and immunological parameters of chronic inflammation showed that this combined treatment increased the efficacy of macrophages, determined by the decrease in the number of parasitized cells, leading to reduced expression of proinflammatory and tissue damage markers. In addition, these drugs in combination fostered wound healing, enhanced the number of fibroblasts, pro-healing cytokines and induced collagen synthesis at the lesion site. Overall, our findings suggest that the combination of the NO donor Ru-NO and Brazilian propolis alleviates experimental ATL lesions, highlighting a new therapeutic option that can be considered for further in vivo investigations as a candidate for the treatment of cutaneous leishmaniasis.

The effect of phospholipase A2 from Crotalus durissus collilineatus on Leishmania (Leishmania) amazonensis infection

In this study, the effect of phospholipase A2 (PLA2) derived from Crotalus durissus collilineatus was evaluated in vitro and in vivo on experimental cutaneous leishmaniasis. The promastigote and amastigote forms treated with PLA2 presented increased growth rate. In vivo studies showed that PLA2-treated Leishmania (Leishmania) amazonensis promastigotes increased the size of lesions in BALB/c mice, and histopathological analysis showed numerous necrotic regions presenting a higher density of polymorphonuclear, mononuclear, and amastigote cells. Additionally, infected macrophages treated with PLA2 were able to generate prostaglandin E2 (PGE2). Cytokine quantification showed that the supernatant from infected macrophages presented moderate and high amounts of IL-2 and IL-10, respectively. However, in PLA2-treated infected macrophages, suppression of IL-2 levels occurred, but not of IL-10 levels. Observation also revealed that both the supernatant and lysate of L. (L.) amazonensis promastigotes exhibited PLA2 activity, which, in the presence of dexamethasone, showed no reduction in their activities; while glucocorticoid maintained the ability of promastigote forms to infect macrophages, which presented values similar to controls. In conclusion, the results indicate that PLA2 may be a progression factor for cutaneous leishmaniasis, since the PLA2 effect suppressed IL-2 levels and generated PGE2, an inflammatory lipid mediator.

Surto de leishmaniose tegumentar americana em Itaporanga, São Paulo (Brasil)

O presente trabalho relata os aspectos epidemiológicos e clínicos de surto de leishmaniose tegumentar americana na região Sudoeste do estado de São Paulo, área de colonização antiga, não associada a derrubadas de matas. Foram examinados 231 indivíduos, observando-se: a) Sessenta e sete indivíduos (29%) apresentavam leishmaniose confirmada pela histopatologia das lesões cutâneas e intradermorreação de Montenegro. Destes casos, 40 (59,7%) eram homens; b) a idade variou entre 2 (5 casos) e 86 anos (1 caso); c) de acordo com o tipo de lesão, observou-se: 54 (80, 6%) pacientes apresentavam úlceras, 13 (19,4%) nódulos, 4 (5,9%) lesões úlcero-vegetantes e 3 (4,4%) cicatrizes típicas; d) a intradermorreção de Montenegro apresentou 94,7% de positividade nos casos de leishmaniose-doença. Este estudo reforça observações prévias de que, além da forma clássica de transmissão, a leishmaniose pode ser transmitida no intra e peri-domicílio.

Sir2-Related Protein 1 from Leishmania amazonensis is a glycosylated NAD(+)-dependent deacetylase

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

Occurrence of sibling species of Lutzomyia longipalpis (Diptera : Psychodidae) in Venezuela: First evidence from reproductively isolated sympatric populations

The delimitation of cryptic species within the main vector of the American visceral leishmaniasis, Lutzomyia longipalpis, remains a topic of controversy. An analysis of generic variability based on 8 enzymatic loci revealed fixed differences in 2 diagnostic loci, adenylate kinase (Ak) and hexokinase (Hk), between sympatric and allopatric populations at 4 localities in Venezuela. The absence of heterozygotes for these 2 loci within 1 locality indicates, for the first time, the presence of 2 sympatric reproductively isolated populations or cryptic species within L. longipalpis. Significant differences were also detected between these cryptic species in the allele frequencies of glucose-6-phosphate isomerase (Gpi) and malate dehydrogenase, decarboxylating (Me). One species showed mean heterozygosities that ranged between 6.6% and 6.7%, with 1.6-1.9 alleles detected per locus, while the other had mean heterozygosities that ranged from 4.3% to 6.3%, with 1.3-1.6 alleles per locus. Comparisons of isozyme profiles with published data suggests that 1 species is similar to the L. longipalpis described in Colombian and Brazilian populations, whereas the other has not been previously reported.

Avaliação do efeito antiparasitário do omeprazol na prevenção do desenvolvimento de lesões cutâneas em hamsters infectados por Leishmania brasiliensis

FUNDAMENTOS: A leishmaniose tegumentar americana permanece doença endêmica em diversas regiões brasileiras. A sobrevivência do parasita no interior dos macrófagos se deve, em parte, pela atividade de uma K+/H+-ATPase de membrana que pode ser inibida pelo omeprazol. OBJETIVOS: Avaliar a eficácia do omeprazol na prevenção do desenvolvimento de lesões de leishmaniose em hamsters. MÉTODOS: Empregaram-se 18 hamsters, divididos em três grupos: o grupo L recebeu apenas a inoculação de L. brasiliensis na pata anterior direita, o grupo O recebeu apenas doses diárias de 0,4mg de omeprazol subcutâneo, e o grupo L+O recebeu o inóculo de leishmanias e o tratamento com omeprazol desde o dia da inoculação. O estudo foi conduzido por 42 dias, realizaram-se medidas dos diâmetros das patas semanalmente, e, ao final do estudo, foram realizados esfregaços das lesões para verificação dos parasitas. RESULTADOS: Os hamsters dos grupos L e L+O desenvolveram lesões de leishmaniose tegumentar havendo ulceração em duas patas do grupo L e uma do grupo L+O. Ao final do estudo, a mobilidade e vitalidade no grupo L foram menores que em L+O, e estas menores que no grupo O. Os diâmetros das patas inoculadas nos grupos L e L+O foram significativamente maiores que no início do estudo (p<0.05). Não houve diferença significativa entre os diâmetros das patas dos grupos L e L+O ao final do estudo (p0,05), sendo detectados parasitas no esfregaço das lesões dos dois grupos. CONCLUSÕES: Omeprazol, no protocolo utilizado, não evitou o desenvolvimento de lesões de leishmaniose tegumentar em hamsters.

Leishmaniose cutânea acidental

Os autores relatam o 3º caso de Leishmaniose acidental em laboratório, ocorrido em aluna do curso de Biologia, que contaminou-se por ocasião da passagem de formas amastigotas de Leishmania (Viannia) braziliensis de hamster infectado para hamster são. Chamam atenção de que, apesar de usar toda proteção exigida, a aluna foi mordida pelo hamster são, havendo como conseqüência, ruptura da luva e contágio através do inóculo.

Phlebotominae (Diptera: Psychodidae) em área de transmissão de leishmaniose tegumentar americana no litoral norte do Estado de São Paulo, Brasil

A região do litoral norte do Estado de São Paulo registrou 14, 30 e 104 casos de leishmaniose tegumentar americana nos anos de 1993, 1994 e 1995 respectivamente. Com objetivo de caracterizar a fauna e a distribuição sazonal e horária das espécies de flebotomíneos foram realizadas coletas quinzenais de formas adultas durante o período de dezembro de 1995 a novembro de 1996, utilizando-se armadilhas luminosas do tipo CDC, no interior da residência, no peridomicílio e na mata durante 12 horas a partir do crepúsculo vespertino. No peridomicílio foi utilizada, durante 6 horas também a partir do crepúsculo vespertino, armadilha de Shannon instalada a 100 metros da casa. A cada 3 meses esta armadilha foi utilizada durante 12 horas. Foram observadas flutuações das densidades populacionais, bem como as ocorrências intra e extradomiciliar das espécies predominantes. Lutzomyia intermedia foi a espécie mais abundante nas diferentes armadilhas utilizadas e nos ambientes investigados.

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.

Proteins of Leishmania (Viannia) shawi confer protection associated with Th1 immune response and memory generation

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

Tratamento da leishmaniose cutanea difusa (LCD) com a associacao antimoniato-N-metilglucamina (Glucantime®) e sulfato de paramomicina (Gabbrox®)

Diffuse cutaneous leishmaniasis (DCL) is a rare form of tegumentary leishmaniasis (TL) and 350 cases have been reported world wide. Presently in Brazil, there were 31 cases reported corresponding to 8.9% of the world cases. The state of Maranhao contributed with ten cases (32.3%) of national reports. Recently the authors had opportunity to follow two new cases of DCL, both from the countryside of that state totaling 12 cases. The parasite Leishmania L. amazonensis was incriminated in the disease, confirming the available data as being the unique species to produce DCL in this state. The therapy associating meglumine anthimoniate with paramomicine sulphate (Gabbrox®) during 90 days, showed good tolerance and favorable response, being another option for fills form of DCL that constituted a challenge to science so far.

Changes in amounts of total salivary gland proteins of Lutzomyia longipalpis (Diptera: Psychodidae) according to age and diet

Saliva plays important roles in facilitation of a bloodmeal, lubrication of mouthparts, and parasite transmission for some vector insects. Salivary composition changes during the lifetime of an insect, and differences in the salivary profile may influence its functions. In this report, the amount and profile of salivary gland protein of the American visceral leishmaniasis vector Lutzomyia longipalpis (Lutz & Neiva, 1912) were analyzed at different times of insect development and diet. Protein content from unfed female sand flies increased significantly with age, and a significant difference was observed in sugar-fed females during the first 10 d of adult life. Salivary protein content sharply decreased 1 d after blood feeding, with gradual increase in concentration the following days. SDS-polyacrylamide gel electrophoresis analysis revealed that most polypeptides present in the saliva of sugar-fed also were present in the saliva of blood-fed females. Understanding changes in sand fly's saliva contents at distinct days after emergence and the influence of a bloodmeal in this aspect may reveal the role played by saliva during leishmaniasis transmission. © 2008 Entomological Society of America.

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.