An NDM-Producing Escherichia coli Clinical Isolate Exhibiting Resistance to Cefiderocol and the Combination of Ceftazidime-Avibactam and Aztreonam: Another Step Towards Pan-β-Lactam Resistance

Cefiderocol and ceftazidime-avibactam plus aztreonam (CZA-ATM) are preferred treatment regimens for NDM-producing infections.

We report the case of a United States patient who traveled to India to receive a renal transplant. He subsequently experienced pyelonephritis by an NDM-producing Escherichia coli. Broth microdilution and the broth disk elution method indicated resistance to all β-lactams, including cefiderocol and CZA-ATM. WGS investigations were undertaken to identify resistance mechanisms.

This is the first clinical case of a United States patient harboring an NDM-producing isolate exhibiting resistance to all available β-lactam agents.