In Vivo Characterization of Tebipenem-Pivoxil (SPR994) in a Murine Ascending Escherichia coli Urinary Tract Infection Model Posted on June 11, 2018 at 2:35 pm.Written by Spero Therapeutics View Presentation Post navigation In Vivo Efficacy of Tebipenem-Pivoxil (SPR994) in an Acute Murine Thigh Infection Caused by Escherichia coli and Klebsiella pneumoniaePotent Activity of a Novel Gyrase Inhibitor (SPR719:SPR720) In Vitro and in a Prolonged Acute Mycobacterium abscessus Mouse Model of Infection