An Annotated Checklist of the Human and Animal Entamoeba (Amoebida: Endamoebidae) Species- A Review Article

BACKGROUND The number of valid of pathogen and non-pathogen species of Entamoeba has continuously increased in human and animals. This review is performed to provide an update list and some summarized information on Entamoeba species, which were identified up to the 2014. METHODS We evaluated the Entamoeba genus with a broad systematic review of the literature, books and electronic databases until February 2014. The synonyms, hosts, pathogenicity and geographical distribution of valid species were considered and recorded. Repeated and unrelated cases were excluded. RESULTS Totally 51 defined species of Entamoeba were found and arranged by the number of nuclei in mature cyst according to Levin's grouping. Seven of these species within the 4 nucleate mature cysts group and 1 species with one nucleate mature cyst are pathogen. E. histolytica, E. invadence, E. rananrum and E. anatis causes lethal infection in human, reptiles, amphibians and brides respectively, four species causes non-lethal mild dysentery. The other species were non-pathogen and are important to differential diagnosis of amoebiasis. CONCLUSION There are some unknown true species of Entamoeba that available information on the morphology, hosts, pathogenicity and distribution of them are still very limited and more considerable investigation will be needed in order to clarify the status of them.