Clinical and epidemiological aspects of feline leishmaniasis in Brazil

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

Leishmaniose visceral no Brasil

Visceral leishmaniasis (VL) is among the most important vector-borne diseases that occur in Brazil, mainly due to its zoonotic nature. It is currently present in almost all Brazilian territory, and its control is a challenge both for veterinarians and for public health officials. The etiologic agent is Leishmania infantum (syn chagasi), and the main vector in Brazil is Lutzomyia longipalpis. Of all animals identified as reservoirs of VL, the dog is considered the most important domestic reservoir. Although the disease has already been identified in cats, the epidemiological role of this animal species is still unclear. This article presents a brief review of the epidemiological situation of the disease, its mode of transmission, clinical features in dogs and cats as well as possible risk factors associated with the occurrence of the disease in Brazil.

Caracterização espacial e epidemiológica da ocorrência de infecção por agentes de enfermidades transmissíveis em carnívoros selvagens e domésticos de uma área de Mata Atlântica e de floresta artificial no estado do Paraná

Pós-graduação em Medicina Veterinária - FCAV

Leishmanicidal activity in vitro of Musa paradisiaca L. and Spondias mombin L. fractions

Visceral leishmaniasis (VL) is a zoonotic disease characterized by infection of mononuclear phagocytes by Leishmania chagasi. The primary vector is Lutzomyia longipalpis and the dog is the main domestic reservoir. The control and current treatment of dogs using synthetic drugs have not shown effectiveness in reducing the incidence of disease in man. In attempt to find new compounds with leishmanicidal action, plant secondary metabolites have been studied in search of treatments of VL. This study aimed to evaluate the leishmanicidal activity of Musa paradisiaca (banana tree) and Spondias mombin (cajazeira) chemical constituents on promastigotes and amastigotes of L. chagasi. Phytochemical analysis by column chromatography was performed on ethanol extracts of two plants and fractions were isolated. Thin layer chromatography was used to compare the fractions and for isolation the substances to be used in vitro tests. The in vitro tests on promastigotes of L chagasi used the MTT colorimetric method and the method of ELISA in situ was used against amastigotes besides the cytotoxicity in RAW 264.7 cells. Of the eight fractions tested, Sm1 and Sm2 from S. mombin had no action against promastigotes, but had good activity against amastigotes. The fractions Mp1 e Mp4 of M. paradisiaca were very cytotoxic to RAW 264.7 cells. The best result was obtained with the fraction Sm3 from S. mombin with IC50 of 11.26 mu g/ml against promastigotes and amastigotes of 0.27 mu g/ml. The fraction Sm3 characterized as tannic acid showed the best results against both forms of Leishmania being a good candidate for evaluation in in vivo tests. (C) 2012 Published by Elsevier B.V.

Influência de fatores ambientais na Leishmaniose visceral no Rio Grande do Norte

The Visceral Leishmaniose (LV) disease is endemic in some places in Brazil. It is caused by the protozoa Leishmania chagasi, being transmitted for vector, the phlebotomies, Lutzomyia longipalpis. In virtue of the expansion of the illness in Rio Grande do Norte, it is necessary to evaluate the determinative ambient factors in the proliferation of the vector for better control of the illness. The variable rainfall and the social variables had been analyzed using space regression with two models and the ambient variable of ZANE and the variables analyzed in 205 houses in the cities of Natal, Extremoz, Nísia Floresta, São Gonçalo do Amarante, São Jose do Mipibu, Parnamirim and Macaíba the Person and ML Chi-square were used . The analyses had shown that high rainfall, plain relief, the forest, the humid tropical climate the activities of production culture of sugar cane and fruit culture and the presence of bovines increase the risk of the LV. The work showed that it has space aggregation and that ambient factors influence in the LV in the State

Preferência alimentar e identificação das principais fontes de repasto sanguíneo de fêmeas Lutzomyia (Diptera: Psychodidae) em áreas endêmicas para leishmaniose visceral na grande Natal

Leishmaniasis are endemic diseases wild spread in the New and Old World, caused by the flagelated protozoan Leishmania. In the New World, the distribution of different forms of leishmaniasis is mostly in tropical regions. In the State of Rio Grande do Norte, Northeast Brazil, 85% of the captured sand flies fauna is Lutzomyia longipalpis. The distribution of the sand fly vector in the state overlaps with the disease distribution, where the presence of sand flies is associated with presence of animals shelters. The aim of this study was to analyse the blood meal preference of sand flies vector from the genus Lutzomyia spp. in laboratory conditions, to verify the vector life cicle at different temperatures sets and to identify the main blood meal source in endemic areas for visceral leishmaniasis (VL) at peri-urban regions of Natal. Sand flies samples were collected from the municipalities of São Gonçalo do Amarante and Nísia Floresta where female sand flies were grouped for the colony maintenance in the laboratory and for the analysis of the preferred source of sand fly blood meal in natural environment. The prevalence of blood meal preference and oviposition for the females sand flies was 97% for Cavia porcellus with oviposition of 19 eggs/female; 97% for Eqqus caballus with 19 eggs/female; 98% for human blood with 14 eggs/female; 71.3% for Didelphis albiventris with 8.4 eggs/female; 73% for Gallus gallus with 14 eggs/female; 86% for Canis familiaris with 10.3 eggs/female; 81.4% for Galea spixii with 26 eggs/female; 36% for Callithrix jachus with 15 eggs/female; 42.8% for Monodelphis domestica with 0% of oviposition. Female sand flies did not take a blood meal from Felis catus. Sand flies life cycle ranged from 32-40 days, with 21-50 oviposition rates approximately. This study also showed that at 32°C the life cycle had 31 days, at 28° C it had 50 days and at 22°C it increased to 79 days. Adjusting the temperature to 35°C the eggs did not hatch, thus blocking the life cycle. A total of 1540 sand flies were captured, among them, 1.310 were male and 230 were female. Whereas 86% of the sand flies captured were Lu. longipalpis as compared to 10.5% for Lu. evandroi and, 3.2% for L. lenti and 0.3% for Lu whitmani. The ratio between female and male sandfly was approximately 6 males to 1 female. In Nísia Floresta, 50.7% of the collected females took their blood meal from armadillo, 12.8% from human. Among the female sand flies captured in São Gonçalo do Amarante, 80 of them were tested for the Leishmania KDNA infectivity where 5% of them were infected with Leishmania chagasi. Female Lutzomyia spp. showed to have an opportunistic blood meal characteristic. The behavioral parameters seem to have a higher influence in the oviposition when compared to the level of total proteins detected in the host s bloodstream. A higher Lu. longipalpis life cycle viability was observed at 28°C. The increase of temperature dropped the life cycle time, which means that the life cycle is modified by temperature range, source of blood meal and humidity. Lu longipalpis was the most specie found in the inner and peridomiciliar environment. In Nísia Floresta, armadillos were the main source of blood meal for Lutzomyia spp. At São Gonçalo do Amarante, humans were the main source of blood meal due to CDC nets placed inside their houses

Lectina da esponja marinha Tedania ignis: purificação, caracterização e interação com leishmanias

Lectin obtained from the marine sponge Tedania ignis was purified and characterized by extraction of soluble proteins (crude extract) in 50mM Borax, pH 7.5. The purification procedure was carried out by crude extract precipitation with ammonium sulfate 30% (FI). The precipitated was resuspended in the same buffer and fractionated with acetone 1.0 volume (F1.0). A lectin was purified from this specific fraction by using an affinity chromatography Sepharose 6B. This lectin preferentially agglutinated human erythrocytes from B type previously treated with papain enzyme. The hemagglutinating activity lectin was dependent of divalent Mn2+ cation and was inhibited by the carbohydrates galactose, xylose and fructose. SDS-PAGE analysis indicated a molecular mass of the lectin around 45 kDa. This protein showed stability until 40°C for 1 h. Further, it showed activity between pH 2.5 and 11.5, with an enhanced activity at pH 7.5. Leishmania chagasi promastigotes stained with Coomassie brilliant blue R-250 were agglutinated by F1,0 and in the presence of galactose this interaction was abolished. These results show that this lectin could be implicated in defense procedures and it will can be used as biological tools in studies with this protozoon

Análisis de la susceptibilidad de una línea celular de Aedes aegypti (Diptera: Culicidae) a la infección con Leishmania (L) chagasi y Leishmania (V) braziliensis

Se evaluó la susceptibilidad de los cultivos celulares derivados de tejidos embrionarios de Aedes aegypti a la infección con Leishmania (L) chagasi y Leishmania (V) braziliensis, agentes etiológicos de leishmaniasis visceral americana y leishmaniasis cutánea, respectivamente. Metodología: Se seleccionaron células de A. aegypti mantenidas en una mezcla de medio de cultivo Grace/L15, suplementado con suero fetal bovino al 15%, albendazol 5,4 mg/ml y una mezcla de antibióticos, e incubadas a una temperatura promedio de 26 °C. Los cultivos celulares fueron inoculados con promastigotes metacíclicos de la cepa MH/CO/84/CI-044B de L. chagasi y la cepa HOM/BR752903 de L. braziliensis en una concentración de 10 parásitos por célula. Como control positivo de la infección se utilizó la línea celular J774. Resultados: Los registros más altos en el porcentaje de infección y en el número de amastigotes por células en los cultivos celulares A. aegypti y en la línea celular J774 se obtuvieron en los días 6 y 9 pos-infección. Los resultados mostraron interacción, internalización y maduración in vitro de las dos especies del parásito en las células de este insecto no vector de Leishmania. Las células de A. aegypti infectadas mostraron cambios en el área por la influencia de los parásitos, contrario a lo registrado en las células no infectadas (P<0,05). Conclusión: Los cultivos celulares de A. aegypti emergen como un nuevo modelo in vitro para el estudio del ciclo biológico de L. chagasi y L. braziliensis.

Determinantes envolvidos na resposta imune celular humana à infecção por Leishmania infantum chagasi

Visceral leishmaniasis (VL) is a disease caused by protozoa of the Leishmania donovani complex, whose infection has clinical spectrum ranging from asymptomatic infection to active disease characterized by fever, cachexia, hepatosplenomegaly, and immunosuppression. The healing or protective immunity require an antigen-specific type 1. The Montenegro skin test (DTH) has been interpreted as a marker of protective immunity. However, there is no known correlation between the DTH response to type 1 and DTH and immunity of type 1 are maintained in the long term. Thus, a longitudinal study of 8 years, nested in a cohort family held in Brazil, documented the status of DTH and cytokine production by peripheral blood mononuclear cells in response to antigen-specific stimulation. This study was the interdisciplinary approach of physicians, biochemists, nutritionists, veterinary medicine, biology and statistics. The results show that 46.2% of subjects were analyzed DTH positive at baseline. The prevalence of positive and DTH induration size increased with age (p = 0.0021). 15.7% of individuals positive DTH "retro-converted" the negative and 50.4% (64) of individuals negative DTH became positive. The size of DTH induration was correlated significantly with the antigen-induced production of IFN-γ (r = 0.6186, p = 0.0001). IL-6 was secreted at higher levels in peripheral blood mononuclear cells of individuals who "retro-converted" DTH positive to negative than individuals who remained stable DTH status (p = 0.005). Thus, IFN-γ produced by peripheral blood mononuclear cells, may be a surrogate marker for protective immunity instead of the DTH response. In addition, differences in innate immune response may determine whether individuals maintain or eliminate the infection by Leishmania infantum chagasi in asymptomatic patients

Aspectos clínicos e imunológicos da infecção por Leishmania Infantum Chagasi em cães do Rio Grande do Norte / Paula Vivianne Souza de Queiroz. Natal/RN

Conselho Nacional de Desenvolvimento Científico e Tecnológico

A novel A2 allele found in Leishmania (Leishmania) infantum chagasi

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

Detection of Leishmania (L.) chagasi in canine skin

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

Short Report: Heterogeneity of Leishmania infantum chagasi Kinetoplast DNA in Teresina (Brazil)

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

Polymerase chain reaction and real-time PCR for diagnosing of Leishmania infantum chagasi in dogs

A importância do cão como reservatório de L. infantum chagasi no meio urbano tem estimulado a realização de inúmeros trabalhos de avaliação de técnicas de diagnóstico, uma vez que este procedimento, quando realizado corretamente, torna-se um importante passo na prevenção da doença em humanos. Dentre os métodos de diagnóstico, as técnicas moleculares têm adquirido destaque. Objetivou-se neste trabalho verificar o desempenho da Reação em Cadeia da Polimerase (PCR) e da PCR em tempo real (qPCR) para diagnóstico da Leishmaniose Visceral Canina (LVC) utilizando diferentes amostras biológicas. Para tanto foram utilizados 35 cães provenientes de uma área endêmica para LVC, onde foram utilizados para o diagnóstico molecular, aspirado de medula óssea, fragmentos de linfonodo e baço. Neste estudo a qPCR foi capaz de detectar um maior número de animais positivos quando comparada com a PCR. Já entre as diferentes amostras biológicas utilizadas não foi observada diferença significativa na detecção de DNA de L. infantumchagasi por meio da PCR e qPCR. Mesmo assim, considerando a facilidade de obtenção, o linfonodo pode ser considerada como a melhor amostra para diagnóstico molecular da infecção por L. infantum chagasi.