ABSTRACT
Resumen Introducción: La diversidad de las formas clínicas de la leishmaniasis del Nuevo Mundo (desde formas cutáneas localizadas a diseminadas o formas mucosas) causada por especies del subgénero Viannia podría inferir en la eficacia de los tratamientos tópicos. El objetivo del presente trabajo fue determinar las características de la leishmaniasis cutánea producida por infecciones con Leishmania (V.) braziliensis y L.(V.) panamensis en ratones BALB/c y la eficacia de un mismo tratamiento tópico. Materiales y métodos: Después de la infección con cada una de las especies se realizó seguimiento de las lesiones determinando su tamaño (mm ) y características macroscópicas, cada siete días por 150 días. Las características histopatológicas (en lesiones y órganos) fueron determinadas 70, 106 y 150 días post-infección y la eficacia de un tratamiento tópico (cura de lesión y parasitológica) fue determinada después del tratamiento con un gel de miltefosina aplicado una vez al día por 20 días sobre las lesiones. Resultados: Se observó un aumento del tamaño de las lesiones en ambos grupos de ratones, sin embargo, un mayor tamaño de las lesiones e intensidad de la respuesta inflamatoria con menos alteraciones epidérmicas fue encontrada en los ratones infectados con L. (V.) braziliensis. En ningún grupo se encontraron parásitos en órganos (nódulos, bazo e hígado) ni diferencias en la efectividad del tratamiento tópico utilizado. Conclusión: La eficacia del tratamiento tópico utilizado no fue afectada por las diferencias macro y microscópicas encontradas en la leishmaniasis producida por las dos especies de Leishmania evaluadas.
Abstract Introduction: The efficacy of topical treatments could be affected by the diversity of clinical forms (localized or disseminated cutaneous forms, mucosal forms) of New World-leishmaniasis caused by species of Leishmania from the subgenus Viannia. The aim of this study was to determine the cutaneous leishmaniasis features produced after infection with Leishmania (V.) braziliensis and L. (V.) panamensis in BALB/c mice and to determine the efficacy of one topical treatment. Materials and methods: Cutaneous leishmaniasis lesions were followed up after infection determining their lesion-size (mm2) and other macroscopic characteristics every 7 days for 150 days. Histopathological patterns (in lesions and organs) were determined 70, 106 and 150 days post-infection and the efficacy (lesion and parasitological cure) of miltefosine gel applied topical once a day for 20 days was determined. Results: An increase of size-lesions was observed in both groups of mice, however, a higher lesion- size and inflammatory response but lower epidermal changes were observed in L. (V.) braziliensis compared with L. (V.) panamensis infected ones. No parasites were observed in organs (nodules, spleen and liver) and no differences were observed in the effectiveness of the used topical treatment. Conclusion: The efficacy of the topical treatment used was not affected by the macro and microscopic differences produced after infection by the two Leishmania species evaluated.
Subject(s)
Animals , Leishmania braziliensis , Leishmania guyanensis , Mice, Inbred BALB C , Anti-Infective Agents, LocalABSTRACT
Indirect immunofluorescence is the method recommended for the diagnosis of visceral leishmanisis in dogs, however, the accuracy of this technique is low and its use on a large scale is limited. Since ELISA does not present these limitations, this technique might be an option for the detection of IgG or specific IgG1 and IgG2 subclasses. Canine ehrlichiosis is an important differential diagnosis of American Visceral Leishmaniasis (AVL). The present study compared ELISA using Leishmania chagasi and Leishmania braziliensis antigen for the detection of anti-Leishmania IgG and subclasses in serum samples from 37 dogs naturally infected with L. chagasi (AVL) and in samples from four dogs co-infected with L. braziliensis and L. chagasi (CI). The occurrence of cross-reactivity was investigated in control serum samples of 17 healthy dogs (HC) and 35 infected with Ehrlichia canis (EC). The mean optical density obtained for the detection of IgG was significantly higher when L. chagasi antigen was used, and was also higher in subgroup VLs (symptomatic) compared to subgroup Vla (asymptomatic). The correlation between IgG and IgG1 was low. The present results suggest that IgG ELISA using homologous antigen yields the best results, permitting the diagnosis of asymptomatic L. chagasi infection and the discrimination between cases of AVL and ehrlichiosis in dogs.
A imunofluorescência indireta é o método recomendado para o diagnóstico de leishmaniose visceral em cães, entretanto, a acurácia dessa técnica é baixa e seu uso em grande escala é limitado. Uma vez que o ELISA não apresenta essas limitações, essa técnica poderia ser uma opção para a detecção de IgG ou subclasses IgG1 e IgG2 específicas. A ehrlichiose canina é um importante diagnóstico diferencial de Leishmaniose Visceral Americana (LVA). O presente estudo comparou o ELISA usando antígenos de Leishmania chagasi e Leishmania braziliensis para a detecção de IgG e subclasses anti-Leishmania em amostras de soro de 37 cães naturalmente infectados com L. chagasi (LVA) e em amostras de quatro cães co-infectados (CI). A ocorrência de reatividade cruzada foi investigada em amostras de soro controle de 17 animais saudáveis (HC) e 35 de infectados por Ehrlichia canis (EC). A média de densidade óptica obtida para a detecção de IgG foi significantemente maior quando o antígeno de L. chagasi foi usado e também mais elevada no subgrupo LVs (sintomático) quando comparado ao subgrupo LVa (assintomático). A correlação entre IgG e IgG1 foi baixa. O presente resultado sugere que ELISA IgG empregando antígeno homólogo, produz os melhores resultados, permitindo o diagnóstico de infecção assintomática por L. chagasi e a discriminação entre casos de LVA e ehrlichiose em cães.
Subject(s)
Animals , Dogs , Antibodies, Protozoan/blood , Antigens, Protozoan/immunology , Dog Diseases/diagnosis , Immunoglobulin G/immunology , Leishmaniasis, Visceral/veterinary , Antibodies, Protozoan/immunology , Case-Control Studies , Dog Diseases/immunology , Enzyme-Linked Immunosorbent Assay , Fluorescent Antibody Technique, Indirect , Immunoglobulin G/blood , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/immunology , Predictive Value of Tests , Sensitivity and SpecificityABSTRACT
Este estudio describe la evaluación de las actividades citotóxica y leishmanicida del aceite esencial de Matricaria chamomilla, una planta conocida como manzanilla a la que se le atribuye una variedad de usos en la medicina tradicional. La actividad del aceite esencial se evaluó in vitro contra amastigotes axénicos de L. (V) braziliensis, a concentraciones menores o iguales que 250μg/ml, y amastigotes intracelulares de L. (V) braziliensis y L. (V) panamensis, a concentraciones menores o iguales que 30μg/ml. Por su parte, la actividad citotóxica se evaluó contra células mamíferas de la línea promonocítica humana U-937, a concentraciones por debajo de 1,0 mg/ml. El aceite esencial de manzanilla mostró ser activo contra amastigotes intracelulares de L. (V) panamensis y L. (V) braziliensis (CE50 de 2,87 y 10,30μg /ml, respectivamente). Aunque el aceite esencial de manzanilla también mostró ser potencialmente tóxico para las células mamíferas (CL50 de 30,21μg /ml), esta toxicidad fue similar a la mostrada por la Anfotericina B (CL50 de 31,39μg /ml). El aceite esencial de manzanilla no mostró actividad contra las formas axénicas de L. (V) braziliensis, demostrando la importancia del metabolismo del compuesto en el interior de la célula para que se produzca el metabolito activo contra el parásito. Estos resultados aportan bases para sugerir que el aceite esencial de manzanilla tiene potencial para el desarrollo de medicamentos contra Leishmania, el cual debe ser validado en estudios futuros in vivo en modelos animales.
This study describes the evaluation of cytotoxic and leishmanicidal activities for Matricaria chamomilla essential oil. M. chamomilla is a plant commonly named manzanilla that has many uses in traditional medicine. The activity of essential oil was evaluated in vitro against axenic amastigotes of L. (V) braziliensis at concentrations lower than or equal to 250μg/ml and intracellular amastigotes of L. (V) braziliensis and L. (V) panamensis at concentrations lower than or equal to 30μg/ml. On other hand, the cytotoxic activity was assessed against mammalian cells of the promonocytic human cell line U937 at concentrations below 1.0mg/ml. The essential oil of M. chamomilla showed activity against intracellular amastigotes of L. (V) panamensis and L. (V) braziliensis (EC50 of 2.87 and 10.30μg/ml, respectively). Although the essential oil of M. chamomilla also shown to be potentially toxic to mammalian cells LC50 of 30.21μg ml) this toxicity was similar to that shown by Amphotericin B (LC50 of 31.39μg/ml). This essential oil showed no activity against axenic forms of L. (V) braziliensis suggesting the importance of the compound metabolism inside cells to produce the metabolite that would be active against parasites. These results suggest that the essential oil of M. chamomilla has potential for development of drugs anti- Leishmania that must be validated in future studies in vivo using animal models.
Subject(s)
Chamomile , Leishmania braziliensis , Leishmania guyanensis , Matricaria , Biological Products , Cytotoxicity, Immunologic , Leishmaniasis/therapyABSTRACT
INTRODUCTION: American tegumentary leishmaniasis (ATL) represents one of the most important public health issues in the world. An increased number of autochthonous cases of ATL in the Northeastern region of São Paulo State has been documented in the last few years, leading to a desire to determine the Leishmania species implicated. METHODS: PCR followed by DNA sequencing was carried out to identify a 120bp fragment from the universal kDNA minicircle of the genus Leishmania in 61 skin or mucosal biopsies from patients with ATL. RESULTS: DNA sequencing permitted the identification of a particular 15bp fragment (5' GTC TTT GGG GCA AGT... 3') in all samples. Analysis by the neighbor-joining method showed the occurrence of two distinct groups related to the genus Viannia (V) and Leishmania (L), each with two subgroups. Autochthonous cases with identity to a special Leishmania sequence not referenced in Genbank predominated in subgroup V.1, suggesting the possible existence of a subtype or mutation of Leishmania Viannia in this region. In the subgroup L.2, which showed identity with a known sequence of L. (L.) amazonensis, there was a balanced distribution of autochthonous and non-autochthonous cases, including the mucosal and mucocutaneus forms in four patients. The last observation may direct us to new concepts, since the mucosal compromising has commonly been attributed to L. (V.) braziliensis, even though L. (L.) amazonensis is more frequent in the Amazonian region. CONCLUSIONS: These results confirm the pattern of distribution and possible mutations of these species, as well as the change in the clinical form presentation of ATL in the São Paulo State.