Hostname: page-component-586b7cd67f-rdxmf Total loading time: 0 Render date: 2024-11-28T13:55:38.371Z Has data issue: false hasContentIssue false

Echinococcus granulosus equinus: an ultrastructural study of the laminated layer, including changes on incubating cysts in various media

Published online by Cambridge University Press:  06 April 2009

K. Sylvia Richards
Affiliation:
Parasitology Research Laboratory, Department of Biological Sciences, University of Keele, Keele, Staffs ST5 5BG
C. Arme
Affiliation:
Parasitology Research Laboratory, Department of Biological Sciences, University of Keele, Keele, Staffs ST5 5BG
Janine F. Bridges
Affiliation:
Parasitology Research Laboratory, Department of Biological Sciences, University of Keele, Keele, Staffs ST5 5BG

Summary

The microfibrillate component of the laminated layer of Echinococcus granulosus equinus contains, except for the zone adjacent to the germinal layer, aggregates of electron-dense bodies displaying a sub-structure of electron-lucent spheres. The tegumentary syncytial cytoplasm contains randomly distributed electron-dense granules, many occurring near the apical plasmalemma, although exocytosis was rarely seen. Granules, similar in size and sub-structure to the bodies of the aggregates, also occur in the internuncial connexions and tegumentary cytons, suggesting that they may be produced in the cytons and released into the laminated layer via the internuncial connexions and tegumentary cytoplasm. Cysts incubated for 0·5–2·5 h in serum- and non-serum-containing media showed differences from non-incubated cysts. The distal half of the syncytium contained a progressive increase in the number of granules (distal:proximal 1·9:1 at 2·5 h; cf. 1:1 in non-incubated cysts), and exocytosis of granules into the laminated layer adjacent to the cyst had occurred. This cannot be attributed wholly to serum proteins. Cysts incubated for 21 h appeared ‘normal’, suggesting re-establishment of an equilibrium. Since the matrix of the laminated layer is considered homologous to the glycocalyx of other cestodes, the possible protective role played by the granules/bodies, characteristic of Echinococcus spp., is discussed.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1983

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Bortoletti, G. & Ferretti, G. (1978). Ultrastructural aspects of fertile and sterile cysts of Echinococcus granulosus developed in hosts of different species. International Journal for Parasitology 8, 421–31.CrossRefGoogle ScholarPubMed
Freeze, C. (1963). Zum Aufbau des Echinococcus hydatidosus. Zentralblatt für allgemeine Pathologie und patkologische Anatomic 104, 82–4.Google Scholar
Heath, D. D. & Lawrence, S. B. (1976). Echinococcus granulosus: development in vitro from oncosphere to immature hydatid cyst. Parasitology 73, 417–23.CrossRefGoogle ScholarPubMed
Heath, D. D. & Osborn, P. J. (1976). Formation of Echinococcus granulosus laminated membrane in a defined medium. International Journal for Parasitology 6, 467–71.CrossRefGoogle Scholar
Hustead, S. T. & Williams, J. F. (1977). Permeability studies on taeniid metacestodes: I. Uptake of proteins by larval stages of Taenia taeniaeformis, T. crassiceps, and Echinococcus granulosus. Journal of Parasitology 63, 314–21.CrossRefGoogle ScholarPubMed
Kassis, A. I. & Tanner, C. E. (1976). The role of complement in hydatid disease: in vitro studies. International Journal for Parasitology 6, 2535.CrossRefGoogle ScholarPubMed
Kilejlan, A., Sauer, K. & Schwabe, C. W. (1962). Host-parasite relationships in echinococcosis. VIII. Infrared spectra and chemical composition of the hydatid cyst. Experimental Parasitology 12, 377–92.CrossRefGoogle Scholar
Kilejian, A. & Schwabe, C. W. (1971). Studies on the polysaccharides of the Echinococcus granulosus cyst, with observations on a possible mechanism for laminated membrane formation. Comparative Biochemistry and Physiology 40B, 2536.Google ScholarPubMed
Lascano, E. F., Coltorti, E. A. & Varela-Diaz, V. M. (1975). Fine structure of the germinal membrane of Echinococcus granulosus cysts. Journal of Parasitology 61, 853–60.CrossRefGoogle ScholarPubMed
Lopez-Campos, J. L., Linares, J., Alsonso, J., Aneiros, J. & Diaz-Flores, L. (1978). A study of lamellar layer, germinative membranes and teguments of Echinococcus granulosus protoscolex in its human localization. Morfologia normal y patologica, B 2, 99109.Google Scholar
Morseth, D. J. (1967). Fine structure of the hydatid cyst and protoscolex of Echinococcus granulosus. Journal of Parasitology 53, 312–25.CrossRefGoogle ScholarPubMed
Oaks, J. A. & Lumsden, R. D. (1971). Cytochemical studies on the absorptive surfaces of cestodes. V. Incorporation of carbohydrate-containing macromolecules into tegument membranes. Journal of Parasitology 57, 1256–68.CrossRefGoogle Scholar
Richards, K. S. & Arme, C. (1981). Observations on the microtriches and stages in their development and emergence in Caryophyllaeus laticeps (Caryophyllidea: Cestoda). International Journal for Parasitology 11, 369–75.CrossRefGoogle Scholar
Richards, K. S., Arme, C. & Bridges, J. F. (1983). Echinococcus granulosus equinus: an ultrastructural study of murine response to hydatid cysts. Parasitology 86, 407417.CrossRefGoogle ScholarPubMed
Riley, V. (1960). Adaptation of orbital bleeding technique to rapid serial blood studies. Proceedings of the Society for Experimental Biological Medicine 104, 751–4.CrossRefGoogle Scholar
Thomas, J. A. & Kothare, S. N. (1975). Tissue response in hydatidosis. Indian Journal of Medical Research 63, 1761–6.Google ScholarPubMed