Experimental hepatic amoebiasis and its application to chemotherapeutic studies.

Induction of hepatic amoebiasis with two strains of Entamoeba histolytica has been attempted by direct inoculation of trophozoites into the livers of rats, hamsters, and guinea-pigs, and by intravenous injection into guinea-pigs. A high incidence of amoebic abscesses was obtained in hamsters. Rats and guinea-pigs were relatively less susceptible. The two strains of Entamoeba histolytica differed in virulence. Serial liver passage increased their virulence for the hamster liver, and also increased invasiveness to the rat caecum. The chemotherapeutic effects of chloroquine, emetine, and some anilides were determined. The procedure finally adopted was based on mean survival times of treated and untreated animals. Chloroquine and emetine were effective under conditions which greatly favoured the drugs, but the anilides showed little effect.