Using delafloxacin, a 4th generation fluoroquinolone, in combination with nebulised tobramycin to eradicate Pseudomonas aeruginosa in cystic fibrosis

Prompt eradication of Pseudomonas aeruginosa following isolation in sputum samples is a fundamental part of therapy in people with cystic fibrosis in order to prevent chronic infection. Whilst multiple eradication regimens exist, none have been proven to be more efficacious than any other. Eradication treatment is effective but not always successful. Ciprofloxacin has been the preferred choice of oral antimicrobial in these eradication regimens due to its superior in-vitro activity against Pseudomonas aeruginosa compared to other fluoroquinolones. Delafloxacin, a fourth-generation fluoroquinolone, has been shown to have superior activity against Pseudomonas aeruginosa compared to ciprofloxacin in-vitro. We show herein, what we believe is the first documented successful eradication of Pseudomonas aeruginosa in a person with CF following a new isolation of the pathogen using oral delafloxacin in combination with nebulised tobramycin, instead of ciprofloxacin after the failure of first line treatment and the emergence of ciprofloxacin-resistance on antimicrobial sensitivity testing.