Methods: Exfoliated BEC obtained from two healthy volunteers were pooled in PBS, washed twice and resuspended to 105 cells ml-1. Six clinical isolates of C. albicans, one of C. tropicalis and four laboratory strains: C. albicans GDH2346; NCPF3327; C. krusei NCYC993; C. tropicalis MMU1 were grown in Sabouraud broth for 18 h at 37°C, harvested, washed and resuspended in PBS to 106 cfu ml-1. Equal volumes (0.5ml) of candida suspensions and BEC were mixed and incubated for 1 h at 37°C in a shaking water bath (40rpm). The BEC were collected using 12µm pore hydrophilic polycarbonate filters under vacuum. The filters were washed with 30ml of PBS (to remove non-adherent yeast cells), removed and cells transferred onto a glass slide. Slides were examined at x400 magnification and the numbers of adherent yeast cells to 50 BEC were counted. Each assay was repeated four times on two occasions.
Results: There was no significant difference between the clinical isolates in terms of their adhesion to BEC. The most adherent strain C. albicans strain GDH2346 cells adhered in significantly higher numbers than C. krusei, but otherwise no significant difference between strains was observed.
Conclusion: The adhesion of all isolates was very low. In denture plaque Candida is retained primarily on the denture, and is a secondary, rather than a primary colonizer. There was no difference between clinical denture plaque isolates in terms of adhesion to BEC.