In vitro activity of aztreonam in combination with newly developed β-lactamase inhibitors against MDR Enterobacterales and Pseudomonas aeruginosa producing metallo-β-lactamases.

Altogether, these results showed that combinations including aztreonam and novel β-lactamase inhibitors, such as zidebactam, nacubactam or taniborbactam, have a very significant in vitro activity against MDR MBL-producing Enterobacterales clinical isolates, the aztreonam/zidebactam combination being the best option. On the other hand, aztreonam/zidebactam is equivalent to aztreonam/avibactam and cefiderocol among MBL-producing P. aeruginosa isolates.