Compassionate Use of Cefiderocol to Treat a Case of Prosthetic Joint Infection Due to Extensively Drug-Resistant Enterobacter hormaechei.

We report the case of a 67-year old man with a right knee prosthetic joint infection due to extensively drug-resistant Enterobacter hormaechei. The resistance phenotype was due to the overproduction of the intrinsic cephalosporinase (ACT-5) associated with the production of three acquired β-lactamases (CTX-M-15, TEM-1B and OXA-1), and a putative membrane decreased permeability. He was first treated with colistin-tigecyclin due to adverse drug reactions; treatment was switched to cefiderocol for a 12-week antibiotic duration, with a favorable outcome.