Mark DG, Hung YY, Salim Z, et al. - An increasingly common cause of community-onset urinary tract infections (UTIs) in the United States include third-generation cephalosporin-resistant (3GCR) Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis (EKP). Production of extended-spectrum β-lactamases was identified to be the most common cause of the 3GCR antimicrobial resistance pattern in these Enterobacterales species. Researchers herein conducted a retrospective cohort study of all adults admitted with a febrile UTI at 21 Kaiser Permanente Northern California EDs between January 2017 and June 2019, with the aim to report contemporary, emergency department (ED)-focused data on 3GCR-EKP UTI regional prevalence, presentation, antibiotic susceptibility, and empiric treatment patterns, and outcomes. They identified a total of 4,107 patients (median age 73 years and 35% men) who met study inclusion criteria, 530 of whom (12.9%) had a 3GCR-EKP urinary tract infection. Risk factors for a health care-associated or extended-spectrum β-lactamase infection were possessed by 92.8% of case patients and 86.1% of controls. Ciprofloxacin susceptibility rates were 21% vs 88%, and piperacillin/tazobactam susceptibility rates were 89% vs 97%, respectively, when 3GCR-EKP case and non-3GCR-EKP control isolates were compared. This suggests that 3GCR-EKP caused nearly 13% of febrile EKP UTIs requiring hospitalization, and in these cases, initial empiric therapy was often discordant with antimicrobial susceptibility testing. Observations revealed correlation of 3GCR-EKP infections with a longer hospital length of stay and higher 90-day mortality.