Survival of Listeria monocytogenes in experimentally infected mice

Area of Science:

• Microbiology
• Immunology
• Pathogen Survival

Background:

• Listeria monocytogenes is a significant foodborne pathogen.
• Understanding factors affecting Listeria monocytogenes viability is crucial for food safety and public health.
• The role of physiological fluids and host tissues in pathogen survival requires further investigation.

Purpose of the Study:

• To investigate the effect of physiological saline and peptone solutions on Listeria monocytogenes viability.
• To determine if normal splenic tissue inhibits Listeria monocytogenes survival.
• To assess the in vivo survival of Listeria monocytogenes in experimentally infected mice.

Main Methods:

• In vitro assessment of Listeria monocytogenes viability in different suspending fluids (saline vs. peptone).
• In vitro co-culture experiments with Listeria monocytogenes and normal splenic tissue.
• Experimental infection of mice to evaluate Listeria monocytogenes survival in the peritoneal cavity and spleen.

Main Results:

• Physiological saline was found to be detrimental to Listeria monocytogenes viability.
• The median lethal dose (LD50) of Listeria monocytogenes was significantly lower in peptone than in saline.
• Normal splenic tissue did not inhibit the survival of Listeria monocytogenes.
• Listeria monocytogenes survived for 8 days in the peritoneal cavity and at least 11 days in the spleen of experimentally infected mice.

Conclusions:

• The composition of the suspending fluid significantly impacts Listeria monocytogenes viability.
• Host splenic tissue does not appear to be an inhibitory environment for Listeria monocytogenes.
• Listeria monocytogenes exhibits prolonged survival in vivo, highlighting its persistence potential in infected hosts.