Studies on the host-parasite relationships of leptomonas species (Protozoa: Kinetoplastida) of siphonaptera

The host-parasite relationships of Leptomonas ctenocephali from Ctenocephalides canis and Leptomonas sp. from Orchopeas h. howardi and Palaeopsylla m. minor are described. The latter two species of fleas are new host records for kinetoplastid flagellates. Attachment to pylorus and hindgut is by modification of the flagellum; hemidesmosomes are formed on the inner leaflet of the flagellar membrane and flagella-flagella desmosomes anchor adjacent flagella; a palisade of several layers of promastigote forms line the hindguL Many individual flagellar membranes were found to extend around 3·0µm and up to a maximum of 3·9µm along the cuticular surface to which they were attached. In the rectum a specific association between the flagellates and the rectal ampullae is described; flagellates are attached to this surface covering completely each of the ampullae in heavy infections; again several layers of parasites coat the rectal ampullae. Attachment to the rectal ampullae is by the same mechanism as in the hindgut. Few parasites are attached to the rectal wall itself but rosettes of parasites attached by their flagella are observed in the lumen. The structure of the rectal ampullae are briefly described and the host-parasite relationships are discussed in the context of other described systems.