Summary
In this paper we present, based on elaborate ultrastructural studies, data on the existence of both intracellular and extracellular stages of Pneumocystis carinii, which result in a proposal of a new life cycle of the parasite. Up to now the formation of daughter cells in thick-walled pneumocysts is supposed to be the only way of multiplication. The present study shows that in rats treated with cortisone acetate the formation of daughter cells also takes place within thin-walled pneumocysts. In our opinion this way of multiplication is important for the understanding of the rapid increase in number of the parasites in an infected lung.
The presence of pneumocysts inside the alveolar epithelial cells suggests that intracellular development of the parasites can occur, but the method of cell penetration, intracellular multiplication and parasite liberation is still unknown.
Moreover our observations for the first time indicate a direct pathogenicity of the parasites in host cells.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Anderson, T.F.: Techniques for the preservation of three dimensional structure in preparing specimens for the electron microscopy. Trans. N.Y. Acad. Sci. 13, 130–134 (1951)
Awen, C.F., Baltzan, M.A.: Systemic dissemination of Pneumocystis carinii pneumonia. Can. Med. Assoc. J. 104, 809–812 (1971)
Barnett, R.N., Hull, J.G., Vortel, V., Schwarz, J.: Pneumocystis carinii in lymph nodes and spleen. Arch. Pathol. 88, 175–180 (1969)
Bommer, W.: Die interstitielle plasmacelluläre Pneumonie und Pneumocystis carinii. Ergeb. Mikrobiol. 38, 116–197 (1964)
Brzosko, W.J., Madalinski, K., Krawczynski, K., Nowoslawski, A.: Immunohistochemistry in studies on the pathogenesis of Pneumocystis pneumonia in infants. Ann. N.Y. Acad. Sci. 117, 156–170 (1971)
Burke, B.A., Good, R.A.: Pneumocystis carinii infection. Medicine 52, 23–51 (1973)
Campbell, W.G.: Ultrastructure of Pneumocystis in human lung. Arch. Pathol. 93, 312–324 (1972)
Carini, A., Maciel, J.: Ueber Pneumocystis carinii. Zentralbl. Bakteriol. Abt. Orig. 77, 46–50 (1916)
Hammond, D.M., Scholtyseck, E., Miner, M.L.: The fine structure of microgametocytes of Eimeria performans, E. stiedae, E. bovis and E. auburnensis. J. Parasitol. 53, 235–247 (1967)
Henderson, D.W., Humenink, V., Meadows, R., Forbes, I.J.: Pneumocystis carinii pneumonia with vascular and lymph nodal involvement. Pathology 6, 235–241 (1974)
Hennigar, G., Vinijchaikul, K., Roque, A.L., Lyons, H.A.: Pneumocystis carinii pneumonia in an adult. Am. J. Clin. Pathol. 35, 353–364 (1961)
Huang, S.N., Marshall, K.G.: Pneumocystis carinii infection. A cytologic, histologic and electron microscopic study of the organism. Am. Rev. Resp. Dis. 102, 623–635 (1970)
Hughes, W.T., Price, R.A., Kim, H., Cobura, F.P., Grigsby, D., Feldman, S.: Pneumocystis carinii pneumonitis in children with malignancies. J. Pediatr. 83, 404–415 (1973)
Jarnum, S., Rasmussen, E.F., Soeborg Ohlsen, A., Sorensen, A.W.S.: Generalized Pneumocystis carinii infection with severe idiopathic hypoproteïnemia. Ann. Intern. Med. 68, 138–145 (1968)
Ladda, R., Aikawa, M., Sprinz, H.: Penetration of erythrocytes by merozoites of mammalian and avian malarial parasites. J. Farasitol. 55, 633–644 (1969)
Marquardt, W.C.: In: The Coccidia, D.M. Hammond and P.L. Long, eds., pp. 23–43. Baltimore: University Park Press 1973
Miller, L.A., Aikawa, M., Dvorak, J.A.: Malaria (Plasmodium knowlesi) merozoites of mammalian and avian malarial parasites. J. Immunol. 114, 1237–1242 (1975)
Price, R.A., Hughes, W.T.: Histopathology of Pneumocystis carinii infestation and infection in malignant disease in childhood. Hum. Path. 5, 737–753 (1974)
Rahimi, S.A.: Disseminated Pneumocystis carinii in thymic alymphoplasia. Arch. Pathol. 97, 162–166 (1974)
Roberts, W.L., Hammond, D.M., Speer, C.A.: Ultrastructural study of the intra- and extracellular sporozoites of Eimeria callospermophili. J. Parasitol. 56, 907–917 (1970)
Scholtyseck, E., Chobotar, B.: Electron microscopic observations concerning the penetration of a host cell by Eimeria ferrisi in vivo. Z. Parasitenkd. 46, 91–94 (1975)
Seifert, K., Pliess, G.: Beitrag zum Entwicklungscyclus von Pneumocystis carinii auf vergleichend elektronenoptischer und cytochemischer Basis. Beitr. Pathol. Anat. 123, 412–443 (1960)
Shiveley, J.N., Moe, K.K., Dellers, R.W.: Fine structure of Pneumocystis carinii pulmonary infection in foals. Cornell Vet. 64, 72–88 (1974)
Vanek, J., Jirovec, O., Lukes, J.: Interstitial plasma cell pneumonia in infants. Ann. Paediatr. 180, 1–21 (1953)
Vavra, J., Kucera, K.: Pneumocystis carinii Delanoë, its ultrastructure and ultrastructural affinities. J. Protozool. 17, 463–483 (1970)
Vossen, M.E.M.H., Beckers, P.J.A., Meuwissen, J.H.E.Th., Stadhouders, A.M.: Microtubules in Pneumocystis carinii. Z. Parasitenkd. 49, 291–292 (1976)
Vossen, M.E.M.H., Bergers, A.M.G., Stadhouders, A.M., Beckers, P.J.A., Meuwissen, J.H.E.Th.: New aspects of the life cycle of Pneumocystis carinii. Z. Parasitenkd. 51, 213–217 (1977)
Weibel, E.R.: Morphometric estimation of pulmonary diffusion capacity. Respir. Physiol. 11, 54–75 (1970/71)
Weller, R.: Zur Erzeugung von Pneumocystosen im Tierversuch. Z. Kinderheilkd. 76, 336–378 (1955)
Wessel, W., Ricken, D.: Elektronenmikroskopische Untersuchung von Pneumocystis carinii. Virchows Arch. [Pathol. Anat.] 331, 545–557 (1958)
Author information
Authors and Affiliations
Additional information
This study was supported by a grant to P.J.A. Beckers from the Netherlands Organization for the Advancement of Pure Research (Z.W.O.)
Rights and permissions
About this article
Cite this article
Vossen, M.E.M.H., Beckers, P.J.A., Th. Meuwissen, J.H.E. et al. Developmental biology of Pneumocystis carinii, an alternative view on the life cycle of the parasite. Z. F. Parasitenkunde 55, 101–118 (1978). https://doi.org/10.1007/BF00384826
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00384826