Staphylococcal footpad infection in mice.

Area of Science:

• Microbiology
• Immunology
• Infectious Diseases

Background:

• Staphylococcus aureus is a common pathogen causing various infections.
• Understanding the virulence factors of S. aureus is crucial for developing effective treatments.

Purpose of the Study:

• To investigate the local footpad infection model in mice using clinically isolated Staphylococcus aureus strains.
• To evaluate the dose-dependent response and edema-inducing potential of S. aureus.

Main Methods:

• Inoculation of mice footpads with varying doses (10^6 and 10^7 cells) of 55 S. aureus strains.
• Observation and measurement of local swelling and bacterial growth over 24 hours.
• Statistical comparison of footpad swelling with other infection routes (intravenous, intraperitoneal).

Main Results:

• A dose of 10^7 S. aureus cells caused local swelling and bacterial growth within 24 hours.
• A dose of 10^6 cells induced transient swelling.
• Approximately 75% of tested S. aureus strains induced footpad edema at a dose of 10^7 cells.

Conclusions:

• The mouse footpad model is a viable method for assessing S. aureus virulence.
• S. aureus strains exhibit varying degrees of virulence in inducing local footpad edema.
• Dose is a critical factor in the development of S. aureus-induced footpad infections.