Presence of amastigotes in the central nervous system of hamsters infected with Leishmania sp.

Abstract

Visceral leishmaniasis (VL) is a severe chronic disease caused by Leishmania (Leishmania) infantum chagasi. Better knowledge on the effects caused by this disease can help develop adequate clinical management and treatment. Parasitological and immunohistochemical studies were performed golden hamsters Mesocricetus auratus infected with bone marrow from individuals with VL in the State of Mato Grosso do Sul, central-west Brazil. The effects of parasitism in the spleen, liver, kidneys, lungs, heart and brain of the animals were examined. Eighteen hamsters were inoculated intraperitoneally, and six healthy animals were used as negative controls. The animals were kept in the animal house and checked for clinical signs. Specimens of each organ were examined for the presence of amastigotes. Immunohistochemical technique was performed in all brain specimens and organs negative on the direct examination of parasites. Direct examination of amastigotes was positive in the spleen and liver of all infected animals; 33.3% showed the parasite in the kidneys and lungs, and 16.7% in the heart. Parasitic forms were seen in 83.3% (15/18) of the brain examined. Immunohistochemistry confirmed the results of the direct examination, except in two specimens of lung tissue and in the brain specimens. Other studies are needed to further clarify the effect of the parasite in the central nervous system. Keywords: Visceral leishmaniasis, immunohistochemistry, brain, hamster. ResumoA leishmaniose visceral (LV) é uma doença crônica grave, causada pelo parasito Leishmania (Leishmania) infantum chagasi. Esclarecer as alterações provocadas pela doença é fundamental para que se adotem condutas clínicas e de tratamento adequadas. Com o objetivo de analisar a infecção experimental em hamsters da linhagem golden, Mesocricetus auratus, infectados com tecido de medula óssea de pacientes com LV no Estado de Mato Grosso do Sul, foram realizados estudos parasitológicos e de imunomarcação. Foi verificada a distribuição do parasitismo no baço, fígado, rim, pulmão, coração e encéfalo desses animais. Foram utilizados 18 hamsters experimentalmente inoculados via intra-peritoneal, e seis animais sadios como controles negativos. Os animais foram mantidos em biotério de experimentação e observados, em busca de alterações clínicas. Com fragmentos de cada órgão, procedeu-se a confecção de lâminas por aposição para pesquisa de amastigotas. Nos órgãos com resultado negativo na pesquisa direta do parasito, e em todas as amostras de encéfalo, foi realizada a técnica de imunohistoquímica. A pesquisa direta de amastigotas foi positiva no baço e fígado de todos os animais infectados; 33,3% apresentaram o parasito em rim e pulmão, e 16,7% no coração. Quando realizada

Large-Scale Investigation of Leishmania Interaction Networks with Host Extracellular Matrix by Surface Plasmon Resonance Imaging

“…The ␤-amyloid peptide and brevican, both found in the brain, bound to all the stationary-phase promastigotes tested and to most procyclic promastigotes. The ability of Leishmania strains to interact with molecules specifically expressed in the brain might be related to reported instances of central or peripheral neurologic manifestations during Leishmania infection both in humans and in animals (51) and to the detection of amastigotes in the central nervous systems of Leishmania-infected hamsters (52). The presence of brain proteins in the interaction repertoire of Leishmania parasites might ease their interaction with the brain environment.…”

In vitrocytokines profile and ultrastructural changes of microglia and macrophages following interaction withLeishmania

“…Although the presence of amastigotes has been described in the liquor of an infant with clinical signs of kalazar and various case reports of visceral leishmaniasis with neurological signs (Prasad and Sen, 1996;Diniz et al 2010) (see Petersen and Greenlee, 2011), no clinical reports of cutaneous leishmaniasis were described. In line with these reports, only a few others demonstrated CNS involvement in leishmaniasis in dogs Nieto et al 1996;Machado et al 2010;Melo and Machado, 2011) and the presence of amastigotes in the CNS of hamsters (Oliveira et al 2011) and mice (Abreu-Silva et al 2003). In line with these reports, only a few others demonstrated CNS involvement in leishmaniasis in dogs Nieto et al 1996;Machado et al 2010;Melo and Machado, 2011) and the presence of amastigotes in the CNS of hamsters (Oliveira et al 2011) and mice (Abreu-Silva et al 2003).…”

Natural transmission of Leishmania infantum through experimentally infected Phlebotomus perniciosus highlights the virulence of Leishmania parasites circulating in the human visceral leishmaniasis outbreak in Madrid, Spain

“…On the contrary, amastigote forms were found in other not so common or less studied locations such as salivary glands, stomach, intestine, mesenteric glands, lung, kidney, adrenal glands, brain and reproductive organs of the hamster. The presence of amastigotes in renal, gastrointestinal and respiratory systems has been described [ 52 – 54 ] and even in the central nervous system of experimentally infected hamsters and naturally infected dogs [ 55 , 56 ]. Surprisingly, parasites were found in the skin of only one animal.…”