Differentiation of pathogenic and non-pathogenic Entamoeba: has the question been answered?

Pathogenic and non-pathogenic Entamoeba have been separated into two distinct species. Recently, the non-pathogenic E. dispar has been cultivated axenically. However, the genetic variability among different clones from the same strain, experimental production of hybrid clones which may differ from their parents, and the possibility of invasiveness of E. dispar, are some phenomena which may indicate that the last word on distinctiveness of the species has not yet been said.