Introduction:Candida albicans is an opportunistic fungus that is associated with oral carcinogenesis. In addition, biofilm formation has been one of the important virulence factors of the yeast. Streptococcus salivarius K12 is an oral probiotic while Musa acuminata is a well-known prebiotic. The objective of this study is to investigate the effect of S. salivarius K12 and M. acuminata skin aqueous extract (synbiotic) on C. albicans with the hypothesis that S. salivariusK12 and M. acuminata inhibit C. albicans biofilm formation. Methods: To develop mono-species biofilm, C. albicans(ATCC MYA-4901 and cancer isolates, ALC2 and ALC3 strains) and S. salivarius K12 were standardised to 105 cells and 106 cells, respectively and grown in 96-well plate in nutrient broth (NB) or RPMI at 37 °C for 72 h. Polymicro-bial biofilms were developed by inoculating both microorganisms in the same well with similar cell number as in mono-species. To determine the effect of synbiotic, similar protocol was repeated by mixing with 800 mg mL-1 of M. acuminata skin extract and incubated at 37 °C for 72 h. The medium was replenished at every 24 h, aseptically. Finally, the biofilms were assessed using crystal violet assay and the optical density was measured at OD620nm. Results:C. albicans strain MYA-4901 and ALC3, when grown in polymicrobial with S. salivarius K12 in NB that is predominated by yeast-form C. albicans, exhibited decreased biofilms by 71.40±11.7% and 49.40±3.9%, respec-tively when compared to the expected biofilms. Meanwhile in RPMI, which C. albicans strain ATCC MYA-4901, ALC2 and ALC3 were predominated by hyphal-form showed decreased biofilms by 72.0±26.7%, 53.4±14.4% and 65.7±6.7%, respectively when compared to the expected biofilms. Conclusion:S. salivarius K12 and M. acuminata skin extract synbiotic inhibit biofilm formation of C. albicans yeast and hyphal forms thus supported the hypothesis of the present study.
Introduction:Candida spp. are most common opportunistic pathogenic yeast that inhabit human oral cavity, epider-mis, gastrointestinal tract, and vagina leading to candidiasis. The transition of this yeast from commensal to potent pathogen is facilitated by numbers of virulence factors including biofilm formation. While most reports on candidi-asis are associated with formation Candida albicans biofilms, however, non-albicans Candida species prevalence is of growing concern. Recently, the use of probiotics as antifungal and antibiofilm has gained an increasing attention. As such, we aim to evaluate the inhibitory effect of monomicrobial and polymicrobial of Streptococcus salivariuson six strains of NAC namely Candida dubliniensis, Candida glabrata, Candida krusei, Candida lusitanaei, Candida parapsilosis and Candida tropicalis. Methods: Antifungal activity of S. salivarius on NAC species was performed using well diffusion method on Mueller Hinton Agar (MHA) and the diameter of inhibition zone were assessed. For formation of monomicrobial biofilm, standardized cell suspensions of NAC species (1 x 105 cells/ml) and probiotic Streptococcus salivarius (1 x 106 cells/ml) were grown in RPMI or nutrient broth media at 37°C for 72 h. Meanwhile to study polymicrobial biofilm of both NAC and S. salivarius, similar protocol was employed by inoculating both microorganisms with a similar cell density as in monomicrobial. Finally, biofilm formation was assessed through quantification of total biomass by crystal violet (CV) assay and the absorbance of adherent biofilm was measured in triplicate at 620nm. Results: Antifungal susceptibility testing of S. salivarius on all six NAC species discerned no zone of inhibition. Furthermore, our results showed variability of monomicrobial and polymicrobial biofilm biomass between NAC species and growth medium. All six polymicrobial NB-grown and RPMI-grown exhibited decreased of the biofilm formation. C. parapsilosis co-cultured with S. salivarius in NB medium had shown lowest biofilm bio-mass by 75.51+_1.34% while in RPMI medium, C. lusitanaei demonstrated with most reduced biofilm biomass by 67.03+_5.19. Conclusion: Our study elucidated the antagonistic relationship between Streptococcus salivarius and non-albicans Candida by supressing the growth of polymicrobial biofilm and pseudohyphae/hyphae of NAC species.