In Vitro Spectrum of Activity of Finafloxacin, a Novel, pH-Activated Fluoroquinolone, under Standard and Acidic Conditions

Finafloxacin is a novel fluoroquinolone that exhibits enhanced antibacterial activity under acidic conditions. The aim of this study was to define the in vitro pH-activity relationship. Finafloxacin exhibited optimal antibacterial activity between pH 5.0 and 6.0 at which MICs were 4- to 8-fold lower than those determined at neutral pH. These observations were then confirmed against a larger collection of bacteria. These data suggest that finafloxacin could potentially offer a therapeutic advantage within acidic foci of infection.