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Generation of Monocyte-Derived Dendritic Cells with Differing Sialylated Phenotypes
Published on: October 20, 2023
Sialidase of Streptococcus intermedius: a putative virulence factor modifying sugar chains
Ayuko Takao1, Hideaki Nagamune, Nobuko Maeda
1Department of Oral Bacteriology, Tsurumi University, Japan. takao-a@tsurumi-u.ac.jp
Microbiology and Immunology
|December 2, 2010
Summary
A novel sialidase gene (nanA) from Streptococcus intermedius was identified and cloned. This enzyme impacts biofilm stability and bacterial adhesion, suggesting a role in host-bacterial interactions.
Area of Science:
- Microbiology
- Enzymology
- Bacterial Pathogenesis
Background:
- Streptococcus intermedius possesses sialidase activity, crucial for various biological processes.
- Sialidases are enzymes that cleave sialic acids, influencing bacterial interactions with host cells and environments.
Purpose of the Study:
- To clone and characterize a sialidase gene from Streptococcus intermedius.
- To investigate the role of this sialidase in biofilm formation and bacterial adhesion to host cells.
Main Methods:
- Gene cloning and expression in Escherichia coli.
- Construction of a gene-knockout S. intermedius strain.
- Biofilm formation assays with mucin.
- Analysis of bacterial adhesion to HepG2 cells.
Main Results:
- The cloned gene, designated nanA, showed high similarity to Streptococcus pneumoniae nanA.
- Gene knockout abolished sialidase activity, confirming nanA's primary role.
- S. intermedius nanA deletion prevented biofilm degradation and altered bacterial adhesion to HepG2 cells.
- Sialidase pretreatment increased bacterial endocytosis by HepG2 cells.
Conclusions:
- The Streptococcus intermedius nanA gene encodes a significant sialidase.
- Bacterial sialidase activity influences biofilm stability and host cell interactions, potentially via modification of surface sugar chains.
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