Antimicrobial Susceptibility of Enterobacterales causing Bloodstream Infection in United States Medical Centres: Comparison of Aztreonam-Avibactam with Beta-Lactams Active against Carbapenem-Resistant Enterobacterales

Bloodstream infection (BSI) is associated with poor outcomes especially when effective antimicrobial therapy and control of infection source are delayed. As the frequency of Enterobacterales producing metallo-beta-lactamases (MBL) and/or OXA-48-like carbapenemases is increasing in some United States (US) medical centres, effective antimicrobials to treat the infections caused by these organisms are urgently needed. Aztreonam-avibactam is under clinical development for treatment of infections caused by Gram-negative bacteria, including MBL producers. The objective of the study is to evaluate the antimicrobial susceptibility of Enterobacterales causing BSI in US medical centres and compare the activity of aztreonam-avibactam with ceftazidime-avibactam, meropenem-vaborbactam, imipenem-relebactam, cefiderocol, and other antimicrobials used to treat BSI.