The prevalence of selected genes involved in biofilm formation in Candida albicans isolated from the oral cavity

Introduction. C. albicans genome sequencing enables investigation of the role of particular genes in biofilm formation involving the yeast-like fungi.

Aim. The aim of the study was to determine the genotypes of C. albicans isolates on the basis of the presence of the selected genes involved in biofilm formation.

Material and methods. The study material included C. albicans strains isolated from the oral cavity of 654 healthy individuals. The strain biofilm-forming capacity was estimated with the MTT assay and menadione. The presence of HWP1, ALS3, TUP1, NGR1, SAM2 and CYS3 genes was investigated.

Results. In total, 15 gene combinations were found, including nine gene combinations for strains with a confirmed biofilm-forming capacity, 11 – for the strains without this capacity, and five – independent of biofilm-forming capacity. A combination involving all the genes occurred in 72.5% of all biofilm-forming strains and in 53.8% of all strains that do not form biofilm. Moreover, the genetic material of 14.3% of all strains not involved in biofilm formation did not contain any of the studied genes. For one of the biofilm-species, no analyzed genes were found.

Conclusions

1. The absence of correlation between gene combinations HWP1, ALS3, TUP1, NGR1, SAM2 and CYS3 and biofilm-forming capacity of the studied C. albicans strains confirms the multigenetic – and not yet fully known – molecular basis of the formation of this structure. This result corresponds to the data reported by other researchers.

2. Knowledge on the genetic foundations of biofilm formation is still developing and the list of biofilm-related genes has been considerably extended.

3. The absence of correlation between the combinations of investigated genes and the biofilm-forming capacity of the studied C. albicans strains confirms a multigenetic, basis of this structure.

4. The research on genes activated or inhibited during biofilm formation is extremely important, because it would enable the development of effective methods to disturb the biofilm forming process at the molecular level. There is a need for such methods in our clinical practice to prevent biofilm formation in the oral cavity.