The first pediatric case successfully treated with cefiderocol for IMP-type carbapenemase-producing Enterobacterales bacteremia.

Cefiderocol, a novel β-lactam antibiotic, exhibits potent activity against carbapenemase-producing Enterobacterales (CPE). While its clinical efficacy has been reported for infections caused by KPC-type CPE and Stenotrophomonas maltophilia, evidence regarding its effectiveness against IMP-type CPE remains primarily derived from in vitro studies, with limited clinical data available. This is the first pediatric case successfully treated with cefiderocol for IMP-type CPE bacteremia. He was a 6-year-old boy with inherited glycosylphosphatidylinositol deficiency and acute lymphoblastic leukemia undergoing chemotherapy. He developed bacteremia that blood culture multiplex PCR identified Klebsiella pneumoniae with IMP gene. The combination therapy of cefiderocol 60mg/kg/dose every 8 hours and gentamicin 5mg/kg/dose once daily sterilized blood culture, and subsequent monotherapy with cefiderocol was continued for a total of 14 days. Additional molecular test in the strain detected IMP-1 carbapenemase, SHV extended spectrum β-lactamase and EBC-type AmpC β-lactamase. Cefiderocol was susceptible at minimum inhibitory concentration 0.5μg/mL. Further study is needed for cefiderocol treatment for IMP-type CPE infection in children.