ABSTRACT

Entamoeba histolytica is a human pathogenic amoeba that causes amoebic dysentery in 90 million people and kills up to 100,000 people each year. Entamoeba has two forms: the trophozoite that causes symptoms and the dormant cyst. Infection occurs by ingesting food or water contaminated with cysts. Once ingested by the host, cysts excyst into the trophozoite form in the small intestine. The trophozoites colonize the large intestine and can encyst and pass out of the body to continue the disease cycle. Most studies on these processes have used the related species Entamoeba invadens, a reptile pathogen, because E. histolytica does not encyst well in culture. The purpose of this research was to identify genes in E. invadens involved in excystation that have orthologs in E. histolytica. The research was conducted using AmoebaDB, a bioinformatics database for pathogenic amoebas. The transcriptome data for E. invadens was searched to identify genes that are upregulated five-fold or more during the beginning stages of excystation, thus suggesting a possible role in the conversion from cyst to trophozoite. These genes encode proteins involved in energy production, motility, and pathogenesis, all of which are essential to the survival and purpose of Entamoeba in its trophozoite form.