Production of cecal lesions in newborn guinea pigs with axenically cultivated Entamoeba histolytica.

The production of cecal lesions with axenically cultivated Entamoeba histolytica in an experimental animal is reported for the first time. Forty-three newborn guinea pigs (one to five days old) were inoculated via laparatomy with 2.5 x 10(5) to 2 x 10(6) strain HM-1-IMSS amebae. Of 23 animals surviving to the 7th postinoculation day all showed cecal lesions at necropsy regardless of the age of the animal when used or the number of amebae received. Ten animals had lesions visible to the unaided eye and 13 had only microscopic lesions. No lesions were noted in other organs of the abdominal or thoracic regiosn. The use of axenically cultivated ameabae in newborn guinea pigs should prove a useful experimental model for the study of amebiasis.