In vitro activity and clinical use of cefiderocol against Achromobacter xylosoxidans (Review)

Achromobacter xylosoxidans is an emerging non-fermenting gram-negative bacillus that is increasingly associated with multidrug-resistant infections, particularly among vulnerable patient populations, such as patients with cystic fibrosis and lung transplant recipients. The intrinsic and acquired resistance mechanisms of A. xylosoxidans, including efflux pumps, β-lactamase production and altered membrane permeability, limit the effectiveness of standard antimicrobial regimens. Notably, cefiderocol, a siderophore cephalosporin with activity against resistant gram-negative pathogens, has been considered as a potential therapeutic option for A. xylosoxidans infections. In the present narrative review, current evidence on the in vitro activity and clinical use of cefiderocol against A. xylosoxidans is summarised. A structured literature search was conducted using PubMed, Web of Science and Google Scholar to identify relevant studies reporting susceptibility data and clinical outcomes. In conclusion, available in vitro and in vivo studies generally support the activity of cefiderocol against A. xylosoxidans, although some heterogeneity in susceptibility has been observed.