Steroid Derivatives as Potential Antimicrobial Agents Against Planktonic Cells.

In this work, the antibacterial activity of deflazacort and several of its synthetic precursors was tested against a panel of bacterial pathogens responsible for most drug-resistant infections including spp., , , , , and spp. The derivative of deflazacort, PYED-1 (pregnadiene-11-hydroxy-16α,17α-epoxy-3,20-dione-1) showed the best antibacterial activity in a dose-dependent way. We focused on the action of PYED-1 against cells. PYED-1 exhibited an additive antimicrobial effect with gentamicin and oxacillin against the methicillin-resistant isolate 00717. In addition to its antimicrobial effect PYED-1 was found to repress the expression of several virulence factors of , including toxins encoded by the (alpha-haemolysin), (beta-haemolysin), (leucotoxins E-D), and (staphylococcal enterotoxin A) genes, and cell surface factors (fibronectin-binding protein B) and capC (capsule biosynthesis protein C)). The expression levels of autolysin isaA (immunodominant staphylococcal antigen) were also increased.