Experimental Infection of the Rabbit with Endamoeba histolytica

Abstract

Summary 1. Thirty-three rabbits (Experiment I) were inoculated intraoesophageally with cultivated cysts of Endamoeba histolytica. Of this group of animals, 6, or 18 per cent, contracted intestinal amoebiasis as was demonstrated by the recovery of amoebae from intestinal scrapings and the production of lesions. 2. Eleven rabbits (Experiment II) were inoculated intracaecally with trophozoites of E. histolytica. Of this group of animals, 10, or 91 per cent, contracted intestinal amoebiasis as was demonstrated by the recovery of amoebae from intestinal scrapings and the production of lesions. 3. Flask-shaped lesions and “bottle” ulcers were produced in the various animals. 4. In one rabbit lesions were observed not only in the large intestine but also in all portions of the small intestine. 5. The severity of the infections varied from those rabbits having a few small lesions to those having numerous small and large lesions. Many of the latter were fulminating cases and the amoebic infection often produced the death of the animal. 6. Many of the trophozoites of E. histolytica, taken from scrapings of lesions, contained not only erythrocytes, but also numerous bacteria, protozoan flagellates and a fungus. 7. It seems quite possible that the rabbit may prove to be a most satisfactory experimental animal for immunologic and chemotherapeutic studies in amoebiasis.