[Cytopathogenic activity of extracts E. histolytica trophozoites]

Previous studies have not shown any correlation between enzyme activities and pathogenicity of Entamoeba histolytica. The activities analyzed were selected without having proved their involvement in the cytopathogenicity. We are using the reverse approach to study the cytopathogenic factors, i.e., to detect and characterize first the cytopathic effect of amebic extracts on animal cells, and subsequently to try to identify the components involved and to explore their correlation with amebic virulence. Total extracts from E. histolytica trophozoites exert dosedependent toxic and lytic effects upon an animal cell line in culture. Erythocytes from eight mammaliam species have been used as a simple target model for the characterization of the cytolytic affect. Hemolysis by amebic extracts is consistent, reproducible, strain specific and dosedependent. Hemolytic potency is much larger E. histolytica extracts than those from other Entamoeba species. This work appears to open up the study of the biochemical basis of E. histolytica cytopathogenicity.