Abstract
Halicephalobus gingivalis, classified as a free-living nematode, is a known
facultative parasite of horses, zebras and humans. However, detailed
information concerning its internal morphology is lacking, especially in
relation to possible adaptations to its lifestyle as a facultative parasite.
The research presented here uses TEM and PI staining to analyse the
morphology of the intestine of H. gingivalis. Specimens cultured under
different conditions were included to determine if differences in
ultrastructure are induced by culturing method. TEM analysis revealed that
the intestinal tract comprises a single layer of cells in which nine pairs
of nuclei can be distinguished. Further, unusual dichotomously and
trichotomously branched microvilli were observed next to finger-like
cylindrical microvilli, the latter being the most commonly described form in
nematodes. Finally, three different types of secretion vesicles, i.e.,
spherical (type I), thread-like (type II) and enlarged globular (type III),
occurred independently from each other along the intestinal tract. The
relationship of morphological adaptations of the microvilli to parasitism in
nematodes is discussed.
Fatal meningoencephalitis secondary to nematode Halicephalobus gingivalis infection in a human
