Attachment Of Candida Albicans Research Articles

Conditions affecting the amphotericin B mediated inhibition of Candida albicans attachment to cell cultures

Sublethal amounts of amphotericin B inhibited the attachment of Candida albicans to cultured mammalian cells. The extent of inhibition was influenced by the concentration of serum and the growth phase of the yeasts used to inoculate the cell cultures. Yeasts which were in their exponential phase of growth or had formed germ tubes were the most sensitive to amphotericin B. Equivalent amounts of amphotericin B inhibited yeast-mammalian cell interactions to different degrees depending upon the culture's tissue origin.

The use of automated image analysis for rapid measurement of the in vitro attachment of Candida albicans to transparent acrylic

A rapid method for measuring the in vitro attachment of Candida albicans to the surface of transparent acrylic is described. The method involves use of the 'Magiscan' automated image analysis system which measures attachment in terms of percentage area coverage. These measurements correlate highly significantly (P < 0·001) with the number of adherent yeast cells.

The attachment to human buccal epithelial cells by Candida albicans: an in vitro kinetic study using concanavalin A.

The early in vitro kinetics of Candida albicans attachment to human buccal epithelial cells was studied with the aid of an adhesion assay and solutions of concanavalin A (Con A), a lectin which is capable of inhibiting yeast adhesion. Various saccharides and putative receptor analogues were also tested. Solutions of each single reagent were added to tubes containing aliquots of mucosal cells and germinated yeasts at the beginning of a 1-hour incubation period (time O) or at 10 minute intervals during the assay. The number of yeasts attached to 200 mucosal cells was subsequently determined microscopically. Yeast adhesion remained constant following addition of phosphate-buffered saline (PBS) at time 0 or at any time thereafter. However, addition of Con A at 0, 10 or 20 minutes of incubation decreased adhesion significantly to 38%, 45% and 63% of control values. This inhibitory effect dwindled as time of incubation prior to lectin addition increased and Con A could not inhibit adhesion significantly after twenty minutes. Results obtained with Con A using live germinated yeasts were similar to those obtained with formalin-killed C. albicans. The other reagents tested failed to decrease adhesion significantly. These included the putative receptor analogues fibronectin, N-acetyl-d-glucosamine and d-galactose, and several non-specific saccharides such as alpha-d-methylglucopyranoside, d-ribose and d-xylose. It is suggested that in vitro attachment to human mucosal cells by C. albicans is inhibitable up to a defined point in time by a lectin with affinity for mannose-containing surface moieties, but becomes non-reversible thereafter. This experimentally-observed irreversibility is independent of yeast cell viability.

Adherence of Candida species to host tissues and plastic surfaces.

Adherence of Candida species to host tissues and nonbiologic materials has been studied in vivo and in vitro. Attachment of Candida albicans to mucosal cells, fibrin-platelet matrices, vascular endothelial cells, and plastic materials has been examined to elucidate early events in the pathogenesis of mucosal colonization and infection, candidal endocarditis, tissue invasion from the intravascular space, and infection of prosthetic devices. Adherence of C. albicans and Candida tropicalis exceeds that of less virulent Candida species, and germinated C. albicans cells adhere to host tissues more readily than do yeast-phase organisms. The adhesin of Candida that mediates attachment has yet to be characterized at the molecular level; however, on the basis of competitive inhibition by crude and purified cell wall products, blocking by antibody and lectin, and controlled degradation of the cell surface of Candida, it appears that mannans and mannoproteins are important constituents of the adhesin. The methods currently used to assay adherence of Candida all have limitations, and an approach to resolving these limitations is one of several areas that warrant further investigation.