Modulatory Effects of Dexamethasone upon Virulence Attributes of Pseudomonas Aeruginosa ATCC® 27853TM

Background: Pseudomonas aeruginosa is a versatile and opportunistic human pathogen whose virulence derives from several factors as extracellular proteases, pyocyanin and pyoverdin and biofilm formation, among others. Dexamethasone is a glucocorticoid widely used as anti-inflammatory. Despite its immunosuppressive role, the interplay between dexamethasone and bacterial virulence remains uncovered. Objectives: In this study, the dexamethasone modulatory effects on planktonic growth, surface adhesion, cell surface hydrophobicity, biofilm formation and pyocyanin and protease secretion by P. aeruginosa ATCC®27853TM was evaluated. Results and Conclusion: The results showed that dexamethasone decreases planktonic cell growth rate and biofilm development. In other hand, the medicine increases proportional pyocyanin secretion and, in high concentrations, collaborates with the bacterial adherence.