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Main Title 'Giardia muris': Scanning Electron Microscopy of In vitro Excystation.
Author Coggins, J. R. ; Schaefer,III, F. W. ;
CORP Author Health Effects Research Lab., Cincinnati, OH. ;Wisconsin Univ.-Milwaukee. Dept. of Zoology.
Year Published 1984
Report Number EPA/600/J-84-081;
Stock Number PB84-244094
Additional Subjects Electron microscopy ; Parasites ; In vitro analysis ; Mice ; Cultivation ; Reprints ; Giardia muris ; Excystation
Library Call Number Additional Info Location Last
NTIS  PB84-244094 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
A recently developed in vitro excystation procedure results in almost total excystation of Giardia muris, an intestinal parasite of mice. The present experiment examines the G. muris cyst morphology by scanning electron microscopy and evaluates the efficacy of the excystation procedure. Untreated cysts of G. muris were elliptical and displayed a distinctive surface structure. Excystation began almost immediately after incubation had begun and most trophozoites emerged within 30 minutes. Excystation appears to involve flagellar action of the encysted trophozoite. A tear of the wall occurred at one pole. This opening was subsequently enlarged, presumably by flagellar action. Trophozoites emerged, posterior end first, and an associated mucoid-like material was extruded. Newly emerged trophozoites were nearly oval in shape. Trophozoites quickly became flattened, elongated and underwent cytokinesis resulting in two daughter trophozoites. Few non-excysted organisms were seen after 30 minutes incubation.