Susceptibility of Enterobacterales Collected in the Middle East and Turkey to Aztreonam/Avibactam and Comparator Agents Stratified by Infection Source: ATLAS Surveillance Program 2018-2022

Abstract

BACKGROUND

Aztreonam-avibactam (ATM-AVI) is a combination of aztreonam, notable for its stability to metallo-β-lactamases (MBLs), and avibactam, an inhibitor of class A, class C and some class D β-lactamases that inactivate aztreonam and are frequently co-carried with MBLs. ATM-AVI was recently approved in EU for treatment of adult patients with complicated intra-abdominal infections, hospital- and ventilator-associated pneumonia, and complicated urinary tract infections. This study evaluated the activity of ATM-AVI and comparators against Enterobacterales collected in six Middle Eastern countries from various infection sources, including lower respiratory tract infections (LRTI), urinary tract infections (UTI), intra-abdominal infections (IAI), skin and soft tissue infections (SSTI) and bloodstream infections (BSI).

METHODS

From 2018-2022, 6,326 non-duplicate Enterobacterales were collected from 17 hospitals in Israel, Jordan, Kuwait, Qatar, Saudi Arabia and Turkey for which infection source was specified. Susceptibility testing was performed by broth microdilution and interpreted using 2024 EUCAST breakpoints.

RESULTS

ATM-AVI showed excellent in vitro activity against isolates from all infection sources as evidenced by low MIC90 values (0.25 mg/L for BSI, IAI and LRTI isolates; 0.12 mg/L for SSTI and UTI isolates). Overall, ≥99.4% of the population from each infection type was susceptible to ATM-AVI. Among comparators, meropenem (88.0% - 94.4% susceptible) and amikacin (88.1% - 94.5%) were also active. The addition of AVI to ATM increased the susceptibility rate by >35 percentage points for each infection source over ATM alone.

CONCLUSIONS

ATM-AVI was the most potent agent examined regardless of infection source and offers promise for use against multidrug-resistant Enterobacterales, including MBL-carriers.