Abstract
The in vitro excystation of sporozoites ofIsospora suis Biester 1934 is described. Sporocysts ofI. suis lack a Stieda body. Upon incubation in 0.75% sodium taurocholate or in 0.25% trypsin+0.75% sodium taurocholate excystation solutions, sporozoites were released by separation of the sporocyst wall into four plates. Occasionally, the sporocyst wall did not separate completely but opened partially and released the sporozoite. At the time of excystation, sporozoites were short and broad but became elongated after 5 to 10 min in the excystation fluids. Elongate sporozoites measuring 11.7×3.8 μm, had a pointed anterior end and a nucleus located in the posterior half of the cell. Living sporozoites exhibited gliding movements, side-to-side flexion, and probed with their anterior ends. Incubation in 5.25% sodium hypochlorite removed the oocyst walls from most oocysts. Sporozoites did not excyst from sporocysts that were released during treatment with sodium hypochlorite.
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Box ED, Marchiondo AA, Duszynski DW, Davis CP (1980) Ultrastructure ofSarcocystis sporocysts from passerine birds and opossums: comments on classification of the genusIsospora. J Parasitol 66:68–74
Christie E, Pappas PW, Dubey JP (1978) Ultrastructure of excystment ofToxoplasma gondii oocysts. J Protozool 25:438–443
Dubey JP (1975)Isospora ohioensis sp. n, proposed forI. rivolta of the dog. J Parasitol 61:462–465
Dubey JP (1979) Life cycle ofIsospora rivolta (Grassi 1879) in cats and mice. J Protozool 26:433–443
Dubey JP, Fayer R (1976) Development ofIsospora bigemina in dogs and other mammals. Parasitology 73:371–380
Duszynski DW, Brunson JT (1972) The structure of the oocyst and the excystation process ofIsospora marquardti sp.n. from the Colorado pika,Ochotona princeps. J Protozool 19:257–259
Duszynski DW, File SK (1974) Structure of the oocyst and excystation of sporozoites ofIsospora endocallimici n.sp., from the marmosetCallimico goeldii. Trans Amer Micros Soc 93:403–408
Duszynski DW, Speer CA (1976) Excystation ofIsospora arctopitheci Rodhain, 1933 with notes on a similar process inIsospora bigemina (Stiles 1891) Luhe 1906. Z Parasitenk 48:191–197
Eustis SL, Nelson DT (1981) Lesions associated with coccidiosis in nursing piglets. Vet Pathol 18:21–28
Fayer R, Thompson DE (1974)Isospora felis: development in cultured cells with some cytological observations. J Parasitol 60:160–168
Frenkel JK (1977)Besnoitia wallacei of cats and rodents: with a reclassification of other cyst-forming isosporoid coccidia. J Parasitol 63:611–628
Leek RG, Fayer R (1979) Survival of sporocysts ofSarcocystis in various media. Proc Helminthol Soc Wash 46:151–154
Lindsay DS, Current WL, Ernst JV (1982) Sporogony ofIsospora suis Biester 1934 of swine. J Parasitol, in press
Lindsay DS, Stuart BP, Wheat BE, Ernst JV (1980) Endogenous development of the swine coccidium,Isospora suis Biester 1934. J Parasitol 66:771–779 (1980)
Nyberg PA, Knapp SE (1970) Effect of sodium hypochlorite on the oocyst wall ofEimeria tenella as shown by electron microscopy. Proc Helminthol Soc Wash 37:32–36
Roberts WL, Speer CA, Hammond DM (1970) Electron and light microscope studies of the oocysts walls, sporocysts, and excysting sporozoites ofEimeria callospermophili andE. larimerensis. J Parasitol 56:918–926
Speer CA, Duszynski DW (1975) Fine structure of the oocyst walls ofIsospora serini andIsospora canaria and excystation ofIsospora serini from the canary,Serinus canarius L. J Protozool 22:476–481
Speer CA, Hammond DM, Mahrt JL, Roberts WL (1973) Structure of the oocyst and oocyst walls and excystation of sporozoites ofIsospora canis. J Parasitol 59:35–40
Stuart BP, Lindsay DS, Ernst JV, Gosser HS (1980)Isospora suis enteritis in piglets. Vet Pathol 17:84–93
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Lindsay, D.S., Current, W.L. & Ernst, J.V. Excystation ofIsospora suis Biester, 1934 of swine. Z. Parasitenkd. 69, 27–34 (1983). https://doi.org/10.1007/BF00934007
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DOI: https://doi.org/10.1007/BF00934007