In vitro maintenance of juvenile Fasciola gigantica and their use to establish infections in mice.

Studies on the growth of juvenile Fasciola gigantica in vitro on tissue culture feeder layers and their subsequent infectivity for mice have indicated that although no significant growth occurs in vitro the juveniles are not damaged physiologically for at least six weeks. Thus the in vitro system may be used with confidence in studies of the physiology of newly excysted flukes. Significantly more flukes became established in mice from an intraperitoneal injection of juveniles than from an oral infection of metacercariae. This may be due to inappropriate physicochemical conditions for excystment in the gut of the mouse. Early growth of flukes in mice occurred at a similar rate to that in cattle, so the mouse is probably a satisfactory model for studies on migration and establishment of F gigantica.