Enteropathogenic Escherichia coli induces Entamoeba histolytica Levy-like movement on fibronectin-rich substrate by reducing traction forces

Amebiasis, caused by Entamoeba histolytica, is a global health concern, affecting millions and causing significant mortality, particularly in areas with poor sanitation. Although recent studies have examined E. histolyticas interaction with human intestinal microbes, the impact of bacterial presence on the parasites motility, mechanical forces, and their potential role in altering invasiveness have not been fully elucidated. In this study, we utilized a micropillar-array system combined with live imaging to investigate the effects of enteropathogenic Escherichia coli on E. histolyticas motility characteristics, F-actin spatial localization, and traction force exerted on fibronectin-coated substrates. Our findings indicate that co-incubation with E. coli significantly enhances the motility of E. histolytica, as evidenced by the enhancement of Levy-like movement patterns, i.e., increased directionality and velocity. This increased motility is accompanied by a reduction in F-actin-dependent traction forces and podosome-like structures on fibronectin-coated substrates, but with increased F-actin localization in the upper part of the cytoplasm. These findings highlight the role of physical interactions and cellular behaviors in modulating the parasites virulence, providing new insights into the mechanistic basis of its pathogenicity. Author SummaryAmebiasis, caused by the protozoan parasite Entamoeba histolytica, is a major global health issue, affecting around 50 million people and resulting in 100,000 deaths annually. The disease is transmitted through contaminated food and water. Upon reaching the intestines, which are teeming with bacteria, E. histolytica begins its invasion by removing the protective mucus layer, followed by adhering to and detaching enterocytes, leading to the disruption and degradation of the epithelial barrier. Afterwards, E. histolytica invades along the fibronectin-rich basement membrane deep into the crypts of Lieberkuhn, eventually penetrating the fibronectin- rich lamina propria. This leads to further tissue destruction and potential dissemination to distant organs, causing severe complications. In our study, we explored how the presence of enteropathogenic bacteria affects the parasites motility and mechanical force generation, both of which are key to its pathogenicity. Using a micropillar-array system and live imaging, we found that exposure to enteropathogenic Escherichia coli significantly increases E. histolyticas motility while reducing its traction force on fibronectin-rich matrices. These changes in behavior highlight the role of bacterial interactions in enhancing the parasites virulence. Our findings provide important insights into the mechanistic basis of E. histolyticas pathogenicity, offering potential avenues for new treatments against amebiasis.