Dr. Paul Hergenrother fhas developed a new series of broad spectrum fusidic acid derivatives. Designed using two distinct methodologies, these fusidic acid derivatives feature unique side chains and demonstrate improved MIC values when compared with fusidic acid. One series of derivatives displays antibiotic activity against Gram-negative ESKAPE pathogens, including in clinical isolates of P. aeruginosa. The prodrug displays low toxicity in mammalian cells and human serum experiments suggest that it is less protein bound than Fusidic Acid. A second series of derivatives displays potent activity against clinical isolates of Staphylococcus aureus and Enterococcus faecium and an improved resistance profile in vitro and in vivo when compared to fusidic acid. Additionally, these derivatives display in vivo efficacy against an FA-resistant strain of Staphylococcus aureus in a mouse infection model.