Amebicidal Activity of Escherichia coli Nissle 1917 Against Entamoeba histolytica Original paper
Researched by:
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Divine Aleru
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Divine Aleru
Read MoreI am a biochemist with a deep curiosity for the human microbiome and how it shapes human health, and I enjoy making microbiome science more accessible through research and writing. With 2 years experience in microbiome research, I have curated microbiome studies, analyzed microbial signatures, and now focus on interventions as a Microbiome Signatures and Interventions Research Coordinator.
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Microbes
Microbes
Microbes, short for microorganisms, are tiny living organisms that are ubiquitous in the environment, including on and inside the human body. They play a crucial role in human health and disease, functioning within complex ecosystems in various parts of the body, such as the skin, mouth, gut, and respiratory tract. The human microbiome, which is […]
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Divine Aleru
Read More
Researched by:
-
Divine Aleru
ID
Divine Aleru
Read More
Microbiome Signatures identifies and validates condition-specific microbiome shifts and interventions to accelerate clinical translation. Our multidisciplinary team supports clinicians, researchers, and innovators in turning microbiome science into actionable medicine.
Divine Aleru
What was studied?
This study examined the amebicidal activity of Escherichia coli Nissle 1917 against Entamoeba histolytica, with a key focus on how EcN amebicidal activity functions through reactive oxygen species and direct morphological disruption. The researchers explored whether EcN could reduce trophozoite viability and induce oxidative stress in a controlled in vitro system.
Who was studied?
The work used the axenic EGG strain of E. histolytica isolated from a symptomatic patient in Manaus and co-cultured it with EcN prepared at graded concentrations from 10² to 10⁹ CFU mL. Human subjects were not included. The trophozoites served as the biological model for evaluating EcN amebicidal responses, oxidative stress induction, and structural injury.
Most important findings
The study showed that EcN induced a substantial dose-dependent reduction in trophozoite viability, with the highest effect seen at 10⁹ CFU mL after eighteen hours. Trophozoites exposed to EcN showed rounding, vacuolization, reduced size, and visible cytoplasmic loss. EcN also increased superoxide and hydrogen peroxide production at all concentrations, indicating oxidative stress as part of the killing mechanism. These effects highlight a new antimicrobial role for EcN that expands beyond its known antagonism toward bacterial and fungal pathogens.
Key implications
This study suggests that EcN amebicidal activity may offer a promising complementary strategy for managing amebiasis, especially where metronidazole response is incomplete. The oxidative injury and structural damage caused by EcN support its potential role as a microbiome-based therapeutic. These findings also provide a distinct microbial signature that could be relevant for databases tracking probiotic pathogen antagonism. Human studies remain necessary before clinical translation.
E. coli Nissle 1917
Escherichia coli Nissle 1917 (EcN) is a rare, non-pathogenic strain of E. coli discovered during World War I from a soldier who did not get dysentery while others did. Unlike harmful E. coli, EcN acts as a probiotic: it settles in the gut, competes with bad bacteria for food and space, produces natural antimicrobials, and even helps strengthen the gut barrier.