Effect Of BCAT On Inhibiting Candida Albicans Biofilm Formation By Anti-adherent Mechanism

Background: Candida albicans is the most common opportunistic fungal pathogens.Candida albicans biofilm could result in escaping from host immune system and increasing antifungal drugs resistance.bCAT had a strong antifungal activity.Objective: To investigate whether bCAT could inhibit Candida albicans biofilm formation and explore its relationship with the expression of adhesion gene HWP1.Methods: Candida albicans clinical strains and standard strain ATCC10231 were studied,XTT method was used to detect the ability of Candida albicans to form biofilm,the antimicrobial activity of bCAT against planktonic Candida albicans cells was evaluated by CLSI-M27-A3.XTT assay and colony counts were used to assess the ability of bCAT inhibited Candida albicans biofilm formation,and BIC50 was decided by calculating the metabolic activity.The adhesion of Candida albicans reduced by bCAT was visualized under inverted microscope and evaluated by colony counts.Furthermore,the expression of HWP1 was detected by RT-PCR.The statistical significance of the results was tested with one-way analysis of variance(ANOVA)followed by Dunnett T3 test.Results: bCAT killed planktonic Candida albicans cells and inhibited the biofilm formation.It exhibited a range of MICs against planktonic Candida from 40?mol/L to 80?mol/L and played the activity of inhibiting biofilm formation at 80-160?mol/L,bCAT can reduce the adhesion of Candida albicans.Colony counts found that blank control group was 27822.22±2472.74 cfu,160?mol/L,80?mol/L,40?mol/L,20?mol/L,10 ?mol/L bCAT groups were 5355.55±1264.03 cfu,11377.78±2232.58 cfu,17488.89±1136.27 cfu,22377.78±3521.99 cfu,26044.44±1329.57 cfu,respectively.There was a statistically significant difference(F=147.018,P=0.000)among groups,RT-PCR also found the relative expression of HWP1 were 12.24±11.55% in bCAT group.Conclusion: bCAT can prevent Candida albicans biofilm formation,and its mechanism may be deceasing the expression of HWP1 gene results in reducing the adhesion of Candida albicans.These results will provide new data for understanding the innate immune function of CGA derived natural antibacterial peptides,and also provide a new way to solve the problem of drug resistance of Candida albicans.