Variation in adhesion and germ tube formation of oral Candida using Egyptian propolis

Adhesion of Candida cells to surfaces is considered the first step in colonization. Some natural products, such as propolis, could be used to block cell adhesion and therefore preventing colonization. In this study, Egyptian propolis ethanol extract concentrations in the range of 25 to 125 ng/μL were used to inhibit the adhesion of oral Candida. The exopolysaccharides showed a 2.5-fold decrease, while the surface-bound exopolysaccharides showed only about 1.15-fold decrease. On the other hand, surface-bound proteins decreased by 7.5-fold upon the addition of 75 ng/μL propolis. The inhibition of adhesion was detected by scanning electron microscopy. The non-slip incubation assay showed a significant decrease in germ tube formation (GTF) compared with an increase upon the addition of fetal bovine serum and corn meal, both of which had a positive effect on GTF compared with a negative GTF effect when using propolis, suggesting that propolis could be considered a quorum-sensing molecule. The use of propolis would help in maintaining the cleanliness of dental fixtures and (or) treating recurrent candidiasis as a complementary and alternative treatment, especially in elders and immunocompromised patients.