Histopathological study of invasive and non-invasive Entamoeba spp. in experimental rats

Abstract

The genus Entamoeba has many species that are invasive or non-invasive (E. histolytica, E. dispar, and E. moshkovskii).The invasive E. histolytica is the main pathogenic amoeba in human. Amoebiasis involves several stages starting with the adherence of the parasite to the intestinal epithelium, followed by degradation, tissue invasion, and distribution to other organs. The current study investigates the pathological changes of Entamoeba spp. infection in both rectum and cecum of experimental rats. The results showed the histological changes at the 7th, 14th, and 28th day post-infection for the three species. E. histolytica and E. moshkovskii infection showed less pathological changes compared to E. histolytica. These changes include the attachment of the trophozoites to the mucosal layer, significant surface epithelial changes such as dissociation and degeneration in the mucosal layer, and ulceration of the apical surface. Inflammatory cells infiltrate the varied regions, extending into the deep mucosa causing mild architectural alterations. These are features of amoebiasis. The pathological changes reported in E. dispar and E. moshkovskii were less severe than E. histolytica.