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Role of fimbriae in adherence of Streptococcus pyogenes to pharyngeal epithelial cells
T Kasashima1, K Suzuki, N Miyamoto
1Department of Otolaryngology, Nagoya City University Medical School, Japan.
Abstract:
The adherence of bacteria to mucosal surface constitutes the initial, critical step in colonization and infection. Streptococcus Pyogenes (S. pyogenes) is one of the most important bacteria in tonsillitis and pharyngitis. The mode of the adherence of S. pyogenes to pharyngeal epithelial cells and the morphology of S. pyogenes were observed by scanning electron microscopy and transmission electron microscopy. The adherence of S pyogenes to pharyngeal epithelial cells was mediated by the fimbriae radiating from the surface of the bacteria. The M protein-negative (M-) strain had smooth, bare cell walls, whereas the M protein-positive (M+) strain had an exterior covered by hair-like fimbriae.
Insights
Streptococcus pyogenes (S. pyogenes) adheres to throat cells via fimbriae. M protein-positive strains possess these fimbriae, enabling bacterial colonization and infection.
Area of Science:
- Microbiology
- Cell Biology
- Infectious Diseases
Background:
- Bacterial adherence to mucosal surfaces is a crucial step in colonization and infection.
- Streptococcus pyogenes (S. pyogenes) is a significant pathogen associated with tonsillitis and pharyngitis.
Purpose of the Study:
- To investigate the mechanism of S. pyogenes adherence to pharyngeal epithelial cells.
- To elucidate the role of bacterial surface structures in this adherence process.
Main Methods:
- Scanning electron microscopy (SEM) was employed to observe bacterial morphology and adherence.
- Transmission electron microscopy (TEM) provided detailed ultrastructural insights into S. pyogenes.
- Comparison of M protein-negative (M-) and M protein-positive (M+) S. pyogenes strains.
Main Results:
- S. pyogenes adherence to pharyngeal epithelial cells is mediated by fimbriae extending from the bacterial surface.
- M protein-positive (M+) strains exhibited a surface covered with hair-like fimbriae.
- M protein-negative (M-) strains displayed smooth, fimbriae-lacking cell walls.
Conclusions:
- Fimbriae are essential for the adherence of S. pyogenes to human pharyngeal epithelial cells.
- The presence of M protein correlates with the expression of fimbriae, facilitating bacterial colonization.