Transfaunation and Repair of Damage in the Rat Tapeworm, Hymenolepis diminuta

Abstract

Adult rat tapeworms, Hymenolepis diminuta, were successfully implanted by surgical methods into the small intestine of recipient Wistar white rats. Seventeen of 20 worms implanted into 4 hosts were recovered after varying periods of time. Worms succeeded in crawling from implantation sites into regions of optimal character. Growth recovery was rapid: anterior pieces 15 to 20 mm long at implantation were 59 mm long after 4 days, 161 mm long after 8 days, and 373 mm long after 14 days. Reproductive structure and behavior in implants were also normal; egg production had commenced by 8 days, and viable onchospheres appeared in the feces after 14 days. Repair of mutilated scoleces and strobilae was also prompt. Complete ablation of the scolex resulted in inability of the worm to survive. Removal of 3 suckers resulted also in loss of worms. Worms survived with 1 or 2 suckers removed. Seventeen rats which received 67 worms lacking 1 or 2 suckers revealed, at autopsy, 25 vigorous and firmly attached worms. These worms also migrated and developed normal strobilar morphology in the small intestine. Cuticular repair was rapid. Within 4 hours a new, loose and vacuolated cuticula was deposited on the worm area. A gradual return to near-normal histology of the cuticula occurred during the next 27 days. Excised suckers were not regenerated.