Attached
Aims: Biofilms are ubiquitous life forms and their pathogenicity is dictated by the
constituents of the environment. We evaluated the efficacy of three culture media on biofilm formation of Candida species. Role of sucrose, glucose, saccharine, and
inhibitory effect of ayurvedic oral treatments were investigated.
Methods: A 96-well plate was inoculated using 106cell/ml of C.albicans,
C.tropicalis and 1:1 mixed species and growth rates were determined by
measuring the absorbance every 2hrs with the presence of three culture
media(Yeast Nitrogen Base (YNB) supplemented with 100 mM glucose,
Sabouraud Dextrose Broth (SDB) and RPMI 1640), sweeteners (5 and 10%:
glucose, sucrose and saccharin). Adhesion and growth rates were quantified using
MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyItetrazolium bromide) and Crystal
Violet (CV). Inhibitory effect of 0.2% chlohexidine, aqueous extracts of bark of
Mimusops elengi and Tripala (mixture of fruits of Emblica officinalis, Terminalia
bellirica and Terminalia chebula) were investigated against both sessile and
planktonic cells. Scanning electron microscope was performed to assess the
biofilm architecture with different treatments.
Results: All three biofilms showed maximum adhesion with RPMI 1640. SDB
promoted the planktonic cell growth. Glucose and sucrose (5%) had the
maximum effect on adhesion of all three biofilms. Planktonic cell growth was
highest with 5% glucose while biofilm growth was promoted with 5% sucrose.
0.2% chlorhexidine significantly reduced the biofilm formation within 30 seconds
of exposure. Aqueous extract of Triphala (65.0 mg/ml) was effective against
planktonic cells while Mimusops elengi had no inhibitory effect.
Conclusion: RPMI 1640 effectively facilitate in-vitro biofilm formation of
Candida. Our data indicate that researchers should pay more attention on
standardization of growth media for cross comparison purposes as sessile cells act
differently to the planktonic cells. Further sucrose promotes biofilm formation of
Candida compared to glucose and saccharine. Triphala had an inhibitory effect
whereas extracts of Mimusops elengi did not show any inhibitory effect.
Key words- Candida biofilms, Culture media, Sugars, Herbal mouth rinses, 0.2%
chlorhexidine gluconate