Effect of non-steroidal anti-inflammatory drugs and dexamethazone on the biofilm formation and expression of some adhesion-related genes of Candida albicans and Staphylococcus aureus

Candida albicans and Staphylococcus aureus can cause many diseases which are considered in many cases life threatening infections. Their biofilm formation on the surface of medical devices is difficult to be treated. Our study evaluates the effect of some anti-inflammatory drugs on the growth, biofilm formation and the expression of some adhesion-related genes. Antimicrobial activity of the tested drugs was determined by microbroth dilution method, their effect on biofilm formation was determined by crystal violet assay method, the mechanism of action was assessed by scanning electron microscope and ethidium bromide uptake assay. Their effects on the expression of icaA, ALS1 and HWP1 genes were determined by RT-PCR. Diclofenac Sodium had the highest antimicrobial activity followed by Meloxicam. Ethidium bromide uptake increased in the presence of diclofenac sodium in both S. aureus and C. albicans strains. All tested drugs showed significant inhibitory effect on both biofilm formation and the preformed biofilm. NSAIDs, dexamethazone and ketoconazole down-regulated C. albicans tested genes except for ketoprofen that up-regulated HWP1 gene. NSAIDs and levofloxacin down-regulated the expression icaA gene but dexamethazone showed no effect on icaA gene expression. Although, dexamethazone had no antimicrobial activity, it had good anti-biofilm activity against S. aureus and C. albicans.