Entamoeba dispar strains: analysis of polymorphism in Tunisian isolates.

The ability to detect intra-species polymorphism in Entamoeba histolytica and Entamoeba dispar is an important tool for studying geographic distribution and transmission mechanisms. E. dispar and E. histolytica share the same mechanism for transmission among human hosts, and so after differentiation between these species. We studied the intra-species variation and distribution of E. dispar strains obtained from cyst passers, specifically from African students and Tunisian food handlers. We analyzed the polymorphic region of the chitinase protein gene in 13 individuals infected with E. dispar, of which 9 were from Tunisia and 4 from other African countries. We identified 7 different chitinase patterns in Tunisians while the 4 isolates from other countries each had a distinct pattern. Two of the patterns we found have been reported in studies from Mexico and India, possibly indicating worldwide spread of certain strains.