# Evaluation of in vitro efficacy of aztreonam-nacubactam and cefepime-nacubactam against clinical isolates of Stenotrophomonas maltophilia

## TL;DR

This study tested how well two antibiotic combinations work against a type of bacteria called Stenotrophomonas maltophilia, finding that both combinations reduced bacterial growth in the lab.

## Contribution

The study demonstrates that combining β-lactam antibiotics with nacubactam can effectively reduce MICs against S. maltophilia, even when one antibiotic is a substrate for bacterial enzymes.

## Key findings

- Aztreonam-nacubactam significantly reduced minimum inhibitory concentrations (MICs) against S. maltophilia isolates.
- Cefepime-nacubactam also remarkably decreased MICs despite cefepime being a substrate for L1 β-lactamase.
- The results suggest β-lactam–NAC combinations may be promising alternatives for treating S. maltophilia infections.

## Abstract

We evaluated the in vitro activity of aztreonam-nacubactam (ATM-NAC) and cefepime-nacubactam (FEP-NAC) against 53 clinical isolates of Stenotrophomonas maltophilia from blood cultures. Minimum inhibitory concentrations (MICs) were determined via broth microdilution. While ATM-NAC showed more significant MIC reduction, FEP-NAC also remarkably decreased MICs, despite cefepime being a substrate for L1 β-lactamase. These findings suggest the potential of β-lactam–NAC combinations as promising alternatives, warranting further in vivo studies to confirm clinical applicability.