Oral adhesion of yeasts

Area of Science:

• Microbiology
• Biochemistry
• Cell Biology

Background:

• Oral adhesion of yeasts, particularly Candida albicans, is a critical step in oral colonization.
• Understanding the molecular mechanisms of yeast adhesion is essential for developing preventative and therapeutic strategies.

Purpose of the Study:

• To investigate the specific adhesins on Candida albicans and their corresponding receptors on oral epithelial cells.
• To identify factors that promote or inhibit yeast adhesion to oral surfaces.

Main Methods:

• Investigated the role of mannoproteins, glucans, chitin, and cell wall proteins as potential yeast adhesins.
• Utilized concanavalin A and tunicamycin to assess the involvement of mannoproteins in adhesion.
• Examined the effect of germ tubes versus blastospores on adhesion.
• Tested the inhibitory effects of methyl-alpha-D-mannoside, L-fucose, N-acetyl-D-glucosamine, and D-mannose on yeast adhesion.
• Assessed the influence of factors like fibronectin, hydrophobicity, s-IgA, indigenous bacteria, growth phase, divalent cations, serum, saliva, chlorhexidine, and Streptococcus salivarius on adhesion.

Main Results:

• Mannoprotein, particularly in its fibrillar form, is implicated as a key adhesin.
• Inhibition of mannoprotein production significantly reduces adhesion.
• Germ tubes exhibit higher adhesion rates compared to blastospores.
• Specific sugars like methyl-alpha-D-mannoside, L-fucose, N-acetyl-D-glucosamine, and D-mannose may act as either yeast adhesins or epithelial cell receptors.
• Growth conditions (sugar-rich media, stationary phase) and external factors (divalent cations, serum, saliva, chlorhexidine, Streptococcus salivarius) modulate yeast adhesion.

Conclusions:

• Candida albicans oral adhesion is mediated by specific molecular interactions, with mannoproteins and carbohydrate moieties playing significant roles.
• Various host and microbial factors can modulate the adhesion process, offering potential targets for intervention.