Investigative methods for studying the adhesion and cell surface hydrophobicity of candida species: An overview

Abstract

Candidal infections are common opportunistic infections in the compromized and manifest both as superficial and systemic diseases. The superficial infections are by far the commonest form of the disease. Although Candida albicans is the most common Candida species isolated from humans and is responsible for the majority of superficial yeast infections, non-albicans species such as Candida krusei, Candida glabrata, Candida parapsilosis and Candida tropicalis are regularly isolated but to a lesser extent. The adhesion of microorganisms to biological and inert surfaces is a vital prerequisite for successful microbial colonization and infection, and its critical role in the pathogenesis of many fungal infections is widely recognized. Such attachment enables the organisms to avoid dislodgment due to the cleaning action of bathing mucosal secretions, and facilitate infection. Consequently the process of candidal adhesion to biological and inert surfaces has been investigated extensively. These studies include adhesion to biological surfaces such as exfoliated epithelial cells, cultured epithelial cells, endothelial cells, animal tissues and fibrin clots and inert surfaces such as denture prostheses. Cell surface hydrophobicity, a contributory factor facilitating or impeding candidal adhesion has also been investigated by many using a number of techniques, although the biphasic hydrocarbon-aqueous phase assay appears to be the most popular and commonly used. Clearly, an ideal assay for investigating Candida adhesion or cell surface hydrophobicity has yet to be established. However, some assays are better than others with respect to the ease of methodology, reproducibility, and cost effectiveness. In this overview we critically evaluate the investigative methods that are used to assess the adhesion and cell surface hydrophobicity of Candida species.