| Summary: | 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 <i>Staphylococcus aureus, Enterococcus</i> spp., <i>Acinetobacter baumannii</i>, <i>Pseudomonas aeruginosa</i>, <i>Klebsiella pneumoniae</i>, <i>Escherichia coli</i>, and <i>Enterobacter</i> 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 <i>S. aureus</i> cells. PYED-1 exhibited an additive antimicrobial effect with gentamicin and oxacillin against the methicillin-resistant <i>S. aureus</i> isolate 00717. In addition to its antimicrobial effect, PYED-1 was found to repress the expression of several virulence factors of <i>S. aureus</i>, including toxins encoded by the <i>hla</i> (alpha-haemolysin), <i>hlb</i> (beta-haemolysin), <i>lukE-D</i> (leucotoxins E-D), and <i>sea</i> (staphylococcal enterotoxin A) genes, and cell surface factors (<i>fnbB</i> (fibronectin-binding protein B) and <i>capC</i> (capsule biosynthesis protein C)). The expression levels of autolysin <i>isaA</i> (immunodominant staphylococcal antigen) were also increased.
|
|---|