Clinical outcomes in patients with piperacillin/tazobactam-non-susceptible but ceftriaxone-susceptible E. coli or K. pneumoniae bloodstream infection.

This article focuses on comparing clinical outcomes in patients with bloodstream infections (BSI) caused by Escherichia coli or Klebsiella pneumoniae isolates that are non-susceptible to piperacillin/tazobactam but susceptible to ceftriaxone. In a retrospective cohort of 62 patients from a three-hospital health system, no significant difference was found in a composite outcome of 90-day all-cause mortality, hospital readmission, or infection recurrence between those treated definitively with ceftriaxone versus alternative effective antibiotics such as carbapenems or fluoroquinolones. Adjusted analyses and Bayesian modeling supported the conclusion that ceftriaxone is an effective treatment option for these infections. The study highlights the rarity of this resistance pattern and acknowledges limitations including small sample size and lack of genetic sequencing of isolates.