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Updated: Aug 12, 2026
Chronic Salmonella Infected Mouse Model
Published on: May 31, 2010
Development of a murine model of chronic Salmonella infection
S Sukupolvi1, A Edelstein, M Rhen
1Department of Pathology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
Abstract:
The invasive disease caused by Salmonella typhimurium in mice resembles the acute phase of human typhoid fever caused by Salmonella typhi, and experimental murine salmonellosis is a widely used experimental model for systemic salmonellosis. In this paper we demonstrate that murine S. typhimurium infection can also be used to model the development of the chronic carrier state that develops in humans after infection with S. typhi. We describe a virulent variant of S. typhimurium that has decreased expression of AgfA fibers under all environmental conditions studied and that causes a chronic carrier state in BALB/c mice after peroral inoculation. The chronic carrier state is associated with persistence of bacteria in the small intestine, spleen, and liver, and chronic infection continues despite the development of protective immunity to challenge with virulent Salmonella.
Insights
A new Salmonella typhimurium variant causes a chronic carrier state in mice, mimicking human typhoid fever. This model, involving decreased AgfA fiber expression, aids research into persistent Salmonella infections.
Area of Science:
- Microbiology
- Immunology
- Infectious Diseases
Background:
- Murine salmonellosis models systemic salmonellosis, mirroring human typhoid fever.
- A chronic carrier state is a significant aspect of human typhoid fever.
- Understanding chronic Salmonella infections is crucial for public health.
Purpose of the Study:
- To establish a murine model for the chronic carrier state of Salmonella typhi.
- To investigate a virulent Salmonella typhimurium variant with altered AgfA fiber expression.
- To analyze the persistence and immune response during chronic murine salmonellosis.
Main Methods:
- Oral inoculation of BALB/c mice with a virulent Salmonella typhimurium variant.
- Characterization of bacterial variant with decreased AgfA fiber expression.
- Assessment of bacterial persistence in the small intestine, spleen, and liver.
- Evaluation of protective immunity development against virulent Salmonella challenge.
Main Results:
- A virulent Salmonella typhimurium variant with reduced AgfA fibers induced a chronic carrier state in mice.
- Bacteria persisted in the small intestine, spleen, and liver during chronic infection.
- Chronic infection persisted despite the development of protective immunity.
- The murine model effectively replicates the human chronic carrier state.
Conclusions:
- A Salmonella typhimurium variant with decreased AgfA fiber expression can model the human chronic carrier state.
- This model provides insights into bacterial persistence and immune evasion in chronic Salmonella infections.
- Further research using this model can advance strategies for controlling persistent typhoid fever.
