Relationship between cell surface composition, adherence, and virulence of Candida albicans

Abstract

A comparison was made of the adherence to acrylic and to human buccal epithelial cells of seven strains of Candida albicans isolated from active infections (I strains) and two strains obtained from asymptomatic carriers (C strains). After growth in defined medium containing a relatively low concentration (50 mM) of glucose as the carbon source, the adherence of I and C strains to either surface was similar and all strains were sensitive to spheroplast formation with Zymolyase 5000. Growth in medium containing a high concentration (500 mM) of sucrose or galactose enhanced the adherence of I strains up to 5and 11-fold, respectively, and there were corresponding increases in resistance to spheroplast formation. Sucroseor galactose-grown C strains showed only small increases in adherence and remained relatively sensitive to spheroplast formation. When inoculated intravenously into mice, I strains grown in 500 mM sucrose were up to five times more virulent than organisms grown in 50 mM glucose, while I strains grown in 500 mM galactose showed a 5to 24-fold increase in virulence. Fifty percent lethal doses obtained for C strains were similar after growth on all three carbon sources. We conclude that I strains are able to modify their surface composition in response to high concentrations of certain sugars in the growth environment. Such modification can enhance both their ability to adhere to surfaces and their virulence. C strains lack this capability, or possess it to a lower degree, and may therefore have a lower pathogenic potential.

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

“…Since it has been reported that phagocytosis of non-opsonized C. albicans cells by macrophages is mediated by the speci¢c receptors [16], the alterations of physicochemical properties of cell walls of C. albicans caused by binding of hamycin to enhance the recognition of Candida cells by macrophages through these receptors is likely. The ability of Candida cells to adhere to host tissues is considered to be important in colonization or pathogenesis of this pathogenic yeast [17]. In this regard, the hydrophobic Candida cells have been proven to be more virulent than hydrophilic cells in mice [18].…”

Comparison of adherence of Candida albicans and Candida parapsilosis to silicone catheters in vitro and in vivo

“…One in vitro study [16] indicated that the adherence of C. albicans to acrylic surfaces was enhanced by adding various sugars to the growth media when the yeast was in stationary phase [16]. McCourtie et al demonstrated an interstrain variability among C. albicans strains in their ability to modify their surface composition in response to certain sugars [17]. Environmental conditions can thus in¯uence yeast surface components, thereby possibly facilitating adherence.…”

Unequal distribution of adhesins within populations of Candida albicans

“…containing high concentrations of different sugars as the carbon source [4,6,7]. Adhesion is proportional to the concentration of sugar used in each case.…”

“…Adhesion is proportional to the concentration of sugar used in each case. However, equimolar concentrations of different sugars promote adhesion to different extents; galactose is more effective than either sucrose or glucose [6,7]. Enhanced adhesion correlates with increased resistance of the yeast to spheroplast formation and is apparently due to enhanced production of a fibrillar mannoprotein layer on the yeast surface [7,10,11].…”

“…Recent studies of the adhesion of C. albicans to oral surfaces have concentrated on attachment to buccal epithelial cells [1][2][3][4][5][6] or to denture acrylic [6][7][8][9]. With C. albicans strains isolated from active infections, attachment to either surface in vitro is promoted by growing the yeast in defined media 3.…”