Characterization of cerulenin-resistant mutants of Candida albicans

Abstract

Cerulenin, an inhibitor of fatty acid biosynthesis, has been used to study the role of the plasma membrane in germination of Candida albicans. To further elucidate this association, spontaneous, cerulenin-resistant mutants of C. albicans were isolated. Two of the mutants, 4918-2 and 4918-10, were compared biochemically with wild-type cells (4918). All strains grew equally well at 37°C and synthesized fatty acids at comparable rates in the absence of the drug. In the presence of cerulenin, wild-type cells did not proceed through a logarithmic growth stage and exhibited a significantly impaired ability to incorporate [3H]acetate into newly synthesized lipid material. All strains were examined ultrastructurally. Alterations were observed in the membranous structures of cerulenin-treated wild-type cells. Such changes were not observed in cerulenin-treated mutant strains. Further examination of mutant strains revealed differences in cell wall protein and polysaccharide compositions when compared with those of wild-type cells. These apparent alterations in cell surface components may be correlated with the reduced abilities of mutant strains to adhere, in vitro, to mammalian

Characterization of epitopes recognized by Candida factor 1 and 9 antisera by use of Saccharomyces cerevisiae mnn mutants

“…One of the most useful approaches to the study of the structure of antigenic surface determinants is the isolation of mutants that fail to be agglutinated by antisera against individual factors; the rationale behind this approach is that the comparison of the mannan of the mutants and that of the wild-type strain would lead to the identification of the epitopes recognized by the different factor antisera. The basic methodology for isolating mannoprotein mutants was developed by Raschke and coworkers for S. cerevisiae (20), and it has been successfully used to isolate several cell surface mutants of C. albicans (6,8,11,18,36), among them one that is deficient in factor 6 antigenic determinants (18).…”

Reduced expression of the functionally active complement receptor for iC3b but not for C3d on an avirulent mutant of Candida albicans

“…Very recently, Hostetter and Kendick (12) used a different monoclonal antibody (BU-15) directed against the mammalian CR3, which reacted with a 185-kDa protein from C. albicans under nonreducing conditions and with three proteins with molecular masses of 70, 67, and 55 kDa under reducing conditions. Previously we isolated a spontaneous avirulent mutant of C. albicans (11). This mutant, originally isolated for its resistance to the antibiotic cerulenin, has a reduced ability to adhere in vitro to fibrin platelet clots and epithelial cells, to cause endocarditis in a rabbit model (2), and to cause vaginitis in a murine model (15).…”

“…MATERIALS AND METHODS Organisms and culture conditions. C. albicans 4918, a virulent clinical isolate (wt), and 4918-10 (m-10), a spontaneous, avirulent mutant of the wt, were used throughout these studies and have been described previously (4,11,18). Both strains were maintained on Sabouraud dextrose agar slants at 4°C and subcultured monthly.…”

Candida albicans C3d receptor, isolated by using a monoclonal antibody

“…Other Candida spp. were obtained as clinical isolates from the Georgetown University Hospital or were described previously (8). For inoculum preparation, all cultures were first grown on brain heart infusion agar plates (Difco Laboratories, Detroit, Mich.) overnight at 37°C.…”