Ultrastructural studies on cutaneous leishmaniasis in Ecuador.

Abstract

Ultrastructural observations were made of the lesions of three Ecuadorian patients with cutaneous leishmaniasis. Parasites were located both within the macrophages, either inside the intracytoplasmic vacuoles (parasitophorous vacuoles) or free in cytoplasm and outside host cells. Amastigotes were rounded or oval with a mean length of 2.62 ,urn (±0.17 S.D.) and mean width of 2.18 ,urn (±0.28 S.D.). Parasites showed degeneration intracellularly both within the vacuoles and in the cytoplasm of macrophages. Lymphocytes were seen in close contact with parasitized macrophages as well as directly attached to the parasites. Furthermore, spongiotic vesicle was observed in the epidermis where Leishmania parasites were found, surrounded by lymphocytes and other mononuclear cells. Amastigotes attached to mononuclear cells were also observed inside and between the keratinocytes. Mononuclear cells containing melanin granules showed amastigotes in their cytoplasm.The parasite-macrophage relationship, the role of T-cells in combating the parasites and the fate of the parasites inside the host body are d~ussed.

Detection of new endemic areas of cutaneous leishmaniasis in Pakistan: a 6‐year study

“…Electron microscopically, no remarkable difference was seen between the New World 14 and our present Old World leishmaniasis specimens. The amastigotes were confirmed in the sections.…”

Histopathological observations of golden hamsters infected with an Ecuadorian isolate of Leishmania mexicana.

“…Previously, we found the degeneration of parasites inside the macrophages in human specimens (Bhutto et al, 1992 From the present hamster and L. mexicana model, we propose that some unknown factor/factors (as discussed above) under host immune mechanism (s) play an important role and promote the destruction of parasites inside the macrophages, and therefore that effective killing of the parasites finally might result in healing of the lesions. However, the precise conditions and mechanisms of the destruction of parasites were not elucidated in the present study.…”