Activity of mecillinam against USA urinary tract clinical isolates from 2017-2020 including isolates resistant to comparator antibiotics.

To support the clinical development of mecillinam and pivmecillinam in the USA for the treatment of complicated and uncomplicated urinary tract infections, this study investigated the activity of mecillinam compared with other antibiotics against Enterobacterales isolates from patients with UTI in the US during 2017-2020. Mecillinam is a first-in-class amidinopenicillin antibiotic, being the only β-lactam to exert its antibacterial activity through exclusive binding to penicillin-binding protein 2. Pivmecillinam is the oral prodrug of mecillinam and is recommended as a first-line therapy by the Infectious Disease Society of America guidelines for uncomplicated urinary tract infections and is approved for the treatment of uncomplicated urinary tract infections in Europe, Canada and the USA.