Activity of Delafloxacin and Levofloxacin against Stenotrophomonas maltophilia at Simulated Plasma and Intrapulmonary pH Values.

Fluoroquinolones have become a popular treatment option for Stenotrophomonas maltophilia infections. Although levofloxacin is most commonly used, delafloxacin demonstrates comparable activity when evaluated under standard susceptibility testing conditions at neutral pH. At acidic pH, the activity of the anionic delafloxacin is improved, while the activity of the zwitterionic levofloxacin is reduced.

Aztreonam in combination with imipenem-relebactam against clinical and isogenic strains of serine and metallo-β-lactamase-producing enterobacterales.

Objective: The objective of this study was to evaluate the in vitro activity of aztreonam plus imipenem-relebactam against clinical and isogenic strains of Escherichia coli and Klebsiella pneumoniae co-harboring NDM and >1 serine β-lactamase.

Methods: Thirteen isolates were included: 4 clinical E. coli, 4 clinical K.