Maintenance in vitro of Fasciola hepatica

Abstract

A NECESSARY preliminary to a study of the physiology of helminths is their maintenance in vitro, a rare accomplishment. Some nematodes and a few cestodes have been maintained for some time with moderate success, and this is also true for certain small trematodes¹, but not for Fasciola hepatica. This common liver fluke of the sheep has so far lived in vitro only for short periods of about 60 hr. and never more than about three days. These were the best results of experiments² in which worms were taken from the livers of cattle or sheep which had been dead for 1–6 hr. and transported from the abattoir to the. laboratory in cold bile. Batches of seven to nine worms wore then immersed in 500 c.c. of various saline solutions and incubated at 37° C, solutions being changed after 16 hr. and after a further 24 hr. In my opinion, an over-elaborato series of experiments failed because the medium (which contained sodium borate) was unsuitable and the trematodes often moribund at the outset. “Many flukes,” we are informed, “never moved in the laboratory except on strong stimulation”, and results were collected on the basis of 50 per cent survival. More satisfactory methods of culture will serve to keep worms alive in a state of active movement, and such worms will retain the reddish colour and fleshy appearance which is normal to them.