Activity of imipenem-relebactam against multidrug-resistant Pseudomonas aeruginosa from the United States - SMART 2015-2017.

A total of 2732 isolates of Pseudomonas aeruginosa collected at 26 United States clinical laboratories in 2015-2017 were tested for susceptibility to imipenem-relebactam. Imipenem-relebactam MICs were interpreted using 2018 CLSI M100 imipenem breakpoints for P. aeruginosa. A total of 93.9% of P. aeruginosa isolates were susceptible to imipenem-relebactam. Among MDR isolates (n = 750), susceptibility to imipenem-relebactam was 79.7%, 46-73 percentage points higher than to other β-lactams tested. Relebactam restored imipenem susceptibility to 78.3% of imipenem-nonsusceptible isolates (n = 766) and to 69.6% of imipenem-nonsusceptible isolates with MDR phenotypes (n = 500).