Factors governing adherence of Candida species to plastic surfaces

Abstract

The ability of Candida albicans and Candida spp. to adhere to inert polymeric surfaces may allow these organisms direct ingress into the human host. Biophysical characterization of this adherence shows that the forces responsible for such adherence are attractive London-van der Waals forces (or hydrophobic forces) and electrostatic forces. The hydrophobic affinity of yeasts was determined by (i) a water-hydrocarbon two-phase assay and by (ii) measurement of the contact angle (theta) of a liquid droplet on a monolayer of yeast cells. The hydrophobicity of the yeasts correlated with the tendency of yeasts to adhere to polystyrene and was reduced in the presence of Tween 20. The adherence of yeasts to polymers of increasing hydrophobicity (determined by the contact angle method) was directly proportional to theta. Yeast surface charges were altered by selectively blocking amino and carboxyl groups. The more positively charged yeasts adhered in greater numbers. Increasing the molarity of NaCl increased yeast adherence. These forces probably contribute to the negative cooperativity (determined by Scatchard and Hill plot) that characterizes the adherence of yeasts to polymers.

Comparison of Photodynamic Therapy versus conventional antifungal therapy for the treatment of denture stomatitis: a randomized clinical trial

“…to adhere to and colonize acrylic surfaces. Virulence factors of Candida spp., such as cell-surface hydrophobicity [27] and ability to form biofilm [10], increase its adherence to acrylic surfaces. Other investigations have also demonstrated that Candida spp.…”

Antifungal antibiotic hamycin increases susceptibility of Candida albicans to phagocytosis by murine macrophages

“…The cell surface hydrophobicity (CSH) of C. albicans cells was determined exactly as described previously [14]. In the present study, n-hexadecane was used as non-polar solvent.…”

The contribution of electrostatic forces to the process of adherence of Candida albicans yeast cells to substrates

“…However, it is also apparent that the adherence process is not explainable by one single specific event and that several different specific interactions may be occurring [4] or that 'non-specific' forces or events may be contributing to the adherence process. For example, it has long been recognized that hydophobicity contributes to adhesion or adherence of C. albicans in vitro [5] and perhaps in vivo [6]. Although recognized earlier in work on Candida adherence [5], the role of electrostatic forces in the process of adherence of this fungus to substrates has never been investigated systematically.…”

“…For example, it has long been recognized that hydophobicity contributes to adhesion or adherence of C. albicans in vitro [5] and perhaps in vivo [6]. Although recognized earlier in work on Candida adherence [5], the role of electrostatic forces in the process of adherence of this fungus to substrates has never been investigated systematically.…”

“…Previous work by us has established that altering the electrostatic charges on the surface of C. albicans will affect the adherence of yeast cells to underlying substrates. For example, treating yeast cells with formaldehyde increases the net negative surface charge on the microorganism [5] and markedly reduces the number of yeast cells which adhere to the surface of ex vivo porcine endothelium [7]. In addition formaldehyde-treated yeast cells demonstrate a 49% reduction in adherence to a plastic surface, whereas carbodiimide-treated yeast cells which are more positively charged demonstrate a 72% increase in adherence to a plastic surface [5].…”