Trichobilharzia regenti is a bird nasal parasite causing human cercarial dermatitis. Schistosomula are able to migrate via the bird nervous system and then, they mature and lay eggs in the nasal cavity. To some extent they can also migrate and develop in mammals. The present study has shown the developmental differences of T. regenti in the natural (ducks) and the abnormal (mice; inbred strains BALB/c, SCID) hosts. The study describes the following parameters of developing worms: length and width of the body, length and content of the intestine, development of the reproductive organs and characterization of surface and intestinal epithelium by lectin probes. The differences in length and width of schistosomula localized in the spinal cord of various hosts cannot be simply explained and may depend on yet unknown host factors. Moreover, there must be several physiological changes during the migration through the skin, the nervous tissue and the nasal cavity, enabling uptake and digestion of different host components. For example the intestine of schistosomula was mostly filled with light-brown pigmented granules until 6 days p.i. (probably of nervous tissue origin) while the older schistosomula and adult intestine was mostly full of dark-brown pigment (probably of blood origin). Reproductive organs were observed from day 9 p.i. in worms from ducks. Whereas ConA and PSA specifically bound to the surface and intestinal epithelium of schistosomula and adults, only the labelled UEA-I lectin could be used as a surface marker of cercaria-schistosomulum transformation. The results confirmed retarded development of parasites in abnormal hosts; the factor responsible for this phenomenon should be clarified in the future.

Department of Parasitology Faculty of Science Charles University Vinicná 7 128 44 Prague 2 Czech Republic

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Mechanisms of the host immune response and helminth-induced pathology during Trichobilharzia regenti (Schistosomatidae) neuroinvasion in mice

Nitric oxide debilitates the neuropathogenic schistosome Trichobilharzia regenti in mice, partly by inhibiting its vital peptidases

Isoforms of Cathepsin B1 in Neurotropic Schistosomula of Trichobilharzia regenti Differ in Substrate Preferences and a Highly Expressed Catalytically Inactive Paralog Binds Cystatin

Molecular evidence for distinct modes of nutrient acquisition between visceral and neurotropic schistosomes of birds

Changes in surface glycosylation and glycocalyx shedding in Trichobilharzia regenti (Schistosomatidae) during the transformation of cercaria to schistosomulum

Nitric oxide and cytokine production by glial cells exposed in vitro to neuropathogenic schistosome Trichobilharzia regenti

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Cathepsins B1 and B2 in the neuropathogenic schistosome Trichobilharzia regenti: distinct gene expression profiles and presumptive roles throughout the life cycle

In vitro cultivation of early schistosomula of nasal and visceral bird schistosomes (Trichobilharzia spp., Schistosomatidae)