Entamoeba histolytica has failed either to survive for more than a few days or to produce lesions following its introduction into the ceca of germfree guinea pigs. Investigations of certain physical characteristics of the germfree cecum provided no conclusive explanation for this phenomenon. Small, localized, amebic lesions occurred in traumatized tissues or adjacent to the sites of amebic inoculation in germfree guinea pigs which received certain chemical or biological preparations. In these instances, however, the conventional amebic disease did not develop and the lesions were confined to small areas by the defenses of the host. It was concluded that bacteria are involved essentially in the etiology of intestinal amebiasis and that synergism of ameba and bacteria is a prerequisite to development of the disease.
National Institute of Allergy and Infectious Diseases, Laboratory of Torpical Diseases, Bethesda, Maryland.
Lobund Institute, University of Notre Dame, Indiana.
These studies were conducted at the Lobund Institute, University of Notre Dame, aided by a contract between the Office of Naval Research, Department of the Navy, and the University of Notre Dame, NR: 131–167.
Presented at the Fifth Annual Meeting of the American Society of Tropical Medicine and Hygiene, New Orleans, November 3, 1956.