Vavraia lutzomyiae n. sp (Phylum Microspora) infecting the sandfly Lutzomyia longipalpis (Psychodidae, Phlebotominae), a vector of human visceral leishmaniasis

Vavraia lutzomyiae (Microsporida; Pleistophoridae) is a new species parasitic in the tropical phlebotomine sandfly, Lutzomyia longipalpis (Diptera, Psychodidae, Phlebotominae), a major vector of Leishmania chagasi in Latin America where human visceral leishmaniasis is endemic. Infected larvae and pupae were parasitized in the abdomen, and some adults were parasitized in Malpighian tubules and midgut. The sporogonial plasmodium divided by multiple divisions into up to 64 uninucleate sporoblasts. These stages were surrounded outside the plasmalemma by a thick, amorphous dense coat and transformed into a merontogenetic sporophorous vesicle within which the sporonts developed into sporoblasts. The mature microsporidian spores were broadly ellipsoidal and measured 6.1 +/- 0.43 x 3.1 +/- 0.15 mu m. The spore wall consisted of a transparent endospore (similar to 100 rim) and a thin electron dense exospore (similar to 30 nm) with the outer limit slightly undulated. Spores contained a polar filament arranged peripherally in a single layer of eight to mile wide anterior coils (similar to 125 nm diameter), and three to four narrow posterior coils (similar to 70 nm diameter). Transverse sections revealed a concentric layer organization with the internal layer surrounded by numerous (LIP to 25) longitudinal microfibrils. The angle of tilt of the polar filament was about 65-68 degrees. (c) 2005 Elsevier GmbH. All rights reserved.