Biochemical homogeneity of Entamoeba histolytica isolates, especially those from liver abscess

The electrophoretic mobility patterns of four enzymes from trophozoites of Entamoeba histolytica were examined to determine the zymodeme of the amoebae populations involved. E. histolytica populations from aspirated liver pus belonged exclusively to types II and XI of eighteen zymodemes. E. histolytica from cases of amoebic dysentery--i.e., those patients presenting with intestinal ulceration and/or with haematophagous trophozoites in the faeces--also belonged to zymodemes II and XI. However, symptom-free cyst passers harboured E. histolytica belonging to one of several zymodemes none of which corresponded wth the zymodemes of the patients with liver abscesses or amoebic dysentery.