Pathogenicity and virulence of Entamoeba histolytica , the agent of amoebiasis

Abstract

The amoeba parasite Entamoeba histolytica is the causative agent of human amebiasis, an enteropathic disease affecting millions of people worldwide. This ancient protozoan is an elementary example of how parasites evolve with humans, e.g. taking advantage of multiple mechanisms to evade immune responses, interacting with microbiota for nutritional and protective needs, utilizing host resources for growth, division, and encystation. These skills of E. histolytica perpetuate the species and incidence of infection. However, in 10% of infected cases, the parasite turns into a pathogen; the host-parasite equilibrium is then disorganized, and the simple lifecycle based on two cell forms, trophozoites and cysts, becomes unbalanced. Trophozoites acquire a virulent phenotype which, when non-controlled, leads to intestinal invasion with the onset of amoebiasis symptoms. Virulent E. histolytica must cross mucus, epithelium, connective tissue and possibly blood. This highly mobile parasite faces various stresses and a powerful host immune response, with oxidative stress being a challenge for its survival. New emerging research avenues and omics technologies target gene regulation to determine human or parasitic factors activated upon infection, their role in virulence activation, and in pathogenesis; this research bears in mind that E. histolytica is a resident of the complex intestinal ecosystem. The goal is to eradicate amoebiasis from the planet, but the parasitic life of E. histolytica is ancient and complex and will likely continue to evolve with humans. Advances in these topics are summarized here.

Amoebic Dysentery Complicated by Hypovolemic Shock and Sepsis in an Infant with Severe Acute Malnutrition: A Case Report

“…Public health efforts should be directed towards its control, and better diagnostic methods should be employed for distinguishing between pathogenic and non-pathogenic species of Entamoeba [ 20 ]. The goal is to eradicate amoebiasis from the planet, but the parasitic life of E. histolytica is ancient and complex and will likely continue to evolve with humans [ 21 ].…”

First human case of avian influenza A (H10N3) in Southwest China

“…In recent years, human infection with AIV has been frequently reported around the world, particularly involving subtypes H5, H7, and other [2][3][4] . Among these, human infections with H10 avian in uenza virus have been reported globally, including subtypes H10N7, H10N8, and H10N3 5,6 .…”

Entamoeba histolytica: In Silico and In Vitro Oligomerization of EhHSTF5 Enhances Its Binding to the HSE of the EhPgp5 Gene Promoter

“…Throughout the course of host infection, the parasite encounters a myriad of stressful conditions, including acidic pH levels, the presence of noxious agents, engagement with the host's immune defenses, drug exposure, heavy metal toxicity, hypoxia, nutrient scarcity, and thermal fluctuations, among others. Despite these hostile environments, the parasite demonstrates remarkable adaptive capabilities, enabling it to persist and induce amoebiasis [4][5][6][7]. Therefore, it is important to understand the molecular mechanisms that trophozoites employ to overcome stressful situations and ensure their survival.…”