South American Entamoeba dispar strains produce amoebic liver abscesses with different pathogenicities and evolutionary kinetics

• Published in: Acta tropica 2021-12, Vol.224, p.106114-106114, Article 106114
• Main Authors: da Silva, Cezar Augusto Vilela, de Oliveira, Isabela Maria Cardoso, Cruz, Ruth Elizabeth, Silva Prado, Greyce Kelly, Santos, Flaviane Vieira, Neves, Nívea Cristina Vieira, Gomes, Maria Aparecida, Silva Oliveira, Fabrício Marcus, Caliari, Marcelo Vidigal
• Format: Article
• Language: English
• Subjects: Amoebiasis; Amoebic liver abscess; Entamoeba dispar; Erythrophagocytosis
• ISSN: 0001-706X; 1873-6254
• DOI: 10.1016/j.actatropica.2021.106114

•Pathogenic Entamoeba dispar strains could be involved in the development of undiagnosed human clinical conditions.•Heterogeneity in the biological behavior of E. dispar strains is related to their ability to cause liver damage.•Chronic granulomatous inflammation is an effective immune mechanism against E. dispar in amoebic liver abscess. Amoebiasis is a protozoan disease caused by Entamoeba histolytica, and presents a geographic distribution of worldwide amplitude, high incidence, sometimes accompanied by severe clinical manifestations such as amoebic colitis and Amoebic Liver Abscess (ALA), remaining as a public health problem in developing countries. Entamoeba dispar is another species of amoeba that infects approximately 12% of the world's population, and it has previously been classified as noninvasive. However, E. dispar has already been isolated from patients with symptomatic non-dysenteric colitis, as well as its DNA sequences were detected and genotyped in samples from patients with dysenteric colitis, and patients with ALA, suggesting that this species could also be involved in the development of lesions in the large intestine and liver of human beings. In this context, this study aims to evaluate the ability of isolated strains of Entamoeba dispar in South America to cause liver damage, and to better characterize histopathological findings in 3, 8, 12 and 16 days after infection (DAI). Firstly, we assessed whether trophozoites from MCR, ACFN, ICS, ADO and VEJ E. dispar strains, and EGG Entamoeba histolytica strain differed in their in vitro phagocytosis ability, being related to greater ability to phagocyte with greater virulence. Then, we investigate and characterize histopathological changes present in the liver of mice induced by different strains of E. dispar. Our results demonstrated that trophozoites from E. dispar strains are capable of phagocyting human erythrocytes, but in lower amounts than Entamoeba histolytica. In addition, we described and characterized the lesions in different periods after infection by different E. dispar strains, and identified ACFN as the most pathogenic strain, followed by MCR. The large areas of necrosis produced by the ACFN strain as the eighth DAI, which also show high parasitism, led to 100% mortality. On the other hand, the ICS, ADO and VEJ strains did not produce mortality, and this was correlated with the presence of well-developed chronic granulomatous inflammation, necrosis absorption throughout the in