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Streptococcus pyogenes infection in mouse skin leads to a time-dependent up-regulation of protein H expression
Tara C Smith1, Darren D Sledjeski, Michael D P Boyle
1Department of Microbiology and Immunology, Medical College of Ohio, Toledo, OH 43614-5806, USA.
Abstract:
Streptococcus pyogenes protein H (sph) is an immunoglobulin-binding protein present in the Mga regulon of certain M1 serotype isolates. Although sph is present in many strains, it is frequently not expressed. In this paper we show that protein H was highly expressed after bacteria were injected into the skin of mice and were recovered from the blood, kidney, or spleen at various times postinfection. The percentage of protein H-positive colonies increased with time, reaching 100% in the spleen and kidney within 24 to 72 h postinfection. The up-regulation of sph expression was also observed in a mga mutant.
Insights
Streptococcus pyogenes protein H (sph) expression increases significantly in mouse infections. This immunoglobulin-binding protein becomes highly prevalent in organs like the spleen and kidney over time.
Area of Science:
- Microbiology
- Immunology
- Infectious Diseases
Background:
- Streptococcus pyogenes protein H (sph) is an immunoglobulin-binding protein.
- sph is part of the Mga regulon in M1 serotype isolates.
- sph is often not expressed despite being present in many strains.
Purpose of the Study:
- To investigate the expression of Streptococcus pyogenes protein H (sph) during infection.
- To determine if sph expression is regulated in vivo.
Main Methods:
- Infection of mice with Streptococcus pyogenes.
- Recovery of bacteria from blood, kidney, and spleen at various time points.
- Assessment of sph expression levels in recovered bacterial colonies.
- Analysis of sph expression in a mga mutant.
Main Results:
- Protein H was highly expressed after bacteria were injected into mouse skin.
- sph expression increased over time postinfection, reaching 100% in spleen and kidney within 24-72 hours.
- Up-regulation of sph expression was also observed in a mga mutant.
Conclusions:
- Streptococcus pyogenes protein H (sph) expression is significantly up-regulated during systemic infection in a mouse model.
- The Mga regulon may play a role in controlling sph expression in vivo.
- Understanding sph regulation is crucial for developing targeted therapies against Streptococcus pyogenes infections.
