TOPLINE

Starting an effective antibiotic more than 24 hours after blood cultures were drawn was not associated with higher 30-day mortality among patients with bloodstream infections caused by extended-spectrum beta-lactamase (ESBL)-producing Enterobacterales.

METHODOLOGY

• Researchers in Sweden conducted a retrospective cohort study to assess whether a delay in starting effective antibiotics was associated with adverse outcomes in patients with bloodstream infections caused by ESBL-producing Enterobacterales.
• They included 644 adults treated at nine hospitals in the Skåne region from 2013 to 2022 who had bloodstream infections with a single bacterial species and received at least two consecutive doses of piperacillin-tazobactam or a carbapenem.
• Patients were grouped by whether they received effective empirical therapy within 24 hours of blood culture collection (effective group; n = 355; median age, 71 years; 57% men) or did not (ineffective group; n = 289; median age, 74 years; 51% men). Therapy was deemed effective if the antibiotic was active in laboratory susceptibility testing and was given intravenously at an appropriate dose.
• The primary outcome was 30-day all-cause mortality. Secondary outcomes were ICU admission and the length of hospital stay.

TAKEAWAY

• The median time to effective therapy was 1 hour in the effective group and 42 hours in the ineffective group.
• At 30 days, mortality was 9.6% (n = 34) in the effective group and 6.6% (n = 19) in the ineffective group. Ineffective therapy was not associated with higher 30-day mortality after adjustment for illness severity and other factors (P = .13).
• ICU admission was less common in the ineffective group than in the effective group (3.1% vs 7.9%; P = .010), but the association was no longer statistically significant after adjustment.
• Ineffective therapy was also not associated with a longer stay in the hospital.

IN PRACTICE

"[O]ur findings could support antimicrobial stewardship efforts by reducing unnecessary empirical carbapenem use without compromising short-term clinical outcomes in patients with EPE-BSI [ESBL-producing Enterobacterales bloodstream infections], particularly in low-prevalence settings," the authors wrote.

SOURCE

The study was led by Thomas Sahlström Månsson, Sahlgrenska University Hospital, Gothenburg, Sweden. It was published online on September 22, 2026, in Open Forum Infectious Diseases.

LIMITATIONS

Because the study was retrospective, some variables may have been misclassified, and unmeasured factors may have confounded the results. Using all-cause mortality as the endpoint may have weakened associations with infection-related outcomes. The predominance of urinary tract infections caused by Escherichia coli and the low prevalence of ESBL-producing Enterobacterales may have limited generalisability to other infection sources, other Enterobacterales, or settings with higher prevalence.

DISCLOSURES

The study was supported by the Petrus and Augusta Hedlund Foundation, Per Skårman Foundation, Landshövding Per Westling Foundation, and Rune Ljungdahl Foundation, as well as governmental funding for clinical research through the Swedish National Health Service. The authors reported having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.