Cystic metacestodes of a rat-adapted Taenia taeniaeformis established in the peritoneal cavity of scid and nude mice.

In vitro-hatched (but not activated) oncospheres of a rat-adapted strain of Taenia taeniaeformis intraperitoneally inoculated into severe combined immunodeficiency (scid), congenitally athymic (nude) and immunocompetent (normal) female BALB/c mice developed into cystic metacestodes in the peritoneal cavity (but not in the liver) of scid and nude mice exclusively. This suggests that cystic metacestodes of this parasite, usually harboured in the liver only, can establish in scid and nude mice provided that the oncospheres are inoculated into the peritoneal cavity. Immunodeficient mice, especially scid mice, may be a good experimental animal model for the intermediate host of any taeniid species, of human, domestic- or wild-animal origin.