Activity of Imipenem-Relebactam and Comparator Agents against Genetically Characterized Isolates of Carbapenem-Resistant Enterobacteriaceae.

Carbapenem-resistant Enterobacteriaceae (CRE) strains are an urgent public health threat. We evaluated the in vitro activities of 19 antimicrobial agents, including imipenem-relebactam, against (i) 106 CRE bloodstream isolates that primarily expressed Klebsiella pneumoniae carbapenemase (KPC) and (ii) 20 OXA-48-like-expressing CRE isolates. Ninety-five percent of CRE bloodstream isolates were susceptible to imipenem-relebactam. In contrast to their comparable activities against KPC-producing CRE strains, ceftazidime-avibactam was more active in vitro against OXA-48-like CRE strains than was imipenem-relebactam (90% susceptible versus 15% susceptible).