Extracellular adherence protein from Staphylococcus aureus enhances internalization into eukaryotic cells.

Area of Science:

• Microbiology
• Cell Biology
• Infectious Diseases

Background:

• Staphylococcus aureus is a significant human pathogen.
• Bacterial internalization into eukaryotic cells is a key step in pathogenesis.
• The mechanisms by which S. aureus enters host cells are not fully understood.

Purpose of the Study:

• To investigate the role of extracellular adherence protein (Eap) in the internalization of Staphylococcus aureus into eukaryotic cells.
• To elucidate the contribution of Eap to S. aureus pathogenesis.

Main Methods:

• Utilized a Staphylococcus aureus mutant strain deficient in the eap gene (Newman mAH12).
• Complemented the mutant strain with the eap gene to restore function.
• Assessed bacterial adherence and internalization into eukaryotic cells.
• Tested the effect of externally added Eap and antibodies against Eap on internalization.

Main Results:

• The eap-deficient mutant showed increased adherence and internalization compared to the isogenic wild-type.
• Complementation of the mutant restored normal internalization levels.
• Exogenous Eap enhanced internalization of various S. aureus strains and S. carnosus.
• Antibodies against Eap inhibited the internalization process.

Conclusions:

• Extracellular adherence protein (Eap) plays a significant role in enhancing Staphylococcus aureus internalization into eukaryotic cells.
• Eap's broad binding capacity and surface localization contribute to this process.
• A novel Eap-dependent internalization pathway for S. aureus is proposed.