Characterizing Salmonella Typhimurium-induced Septic Peritonitis in Mice

Area of Science:

• Immunology
• Microbiology
• Pathogenesis

Background:

• Sepsis is a life-threatening organ dysfunction caused by a dysregulated host response to infection.
• Existing mouse models for sepsis include lipopolysaccharide (LPS)-induced endotoxemia, cecal ligation and puncture (CLP), and monobacterial infections.
• Salmonella Typhimurium is a Gram-negative intracellular pathogen that can induce typhoid-like disease in mice.

Purpose of the Study:

• To describe a reproducible protocol for inducing and studying Salmonella Typhimurium infection-induced septic peritonitis in mice.
• To investigate the systemic host immune responses during this sepsis model.
• To provide a tool for evaluating the roles of genes and potential therapeutics in bacterial sepsis.

Main Methods:

• Preparation of Salmonella Typhimurium cultures.
• Induction of septic peritonitis in mice via intraperitoneal injection.
• Assessment of bacterial burden, cytokine levels, neutrophil infiltration (via flow cytometry), and survival rates.

Main Results:

• Salmonella Typhimurium infection successfully induced septic peritonitis in mice.
• The model demonstrated increased proinflammatory cytokines and rapid neutrophil infiltration into the peritoneal cavity.
• A significant decrease in survival rates was observed in infected mice.

Conclusions:

• The described protocol offers a highly reproducible method for modeling Salmonella Typhimurium-induced sepsis in mice.
• This model is valuable for studying host immunological responses, genetic factors, and therapeutic interventions in bacterial sepsis.
• The model effectively recapitulates key features of sepsis pathogenesis, including inflammation and organ injury.