TOPLINE

Urine culture (UC) identified the same pathogen as blood culture (BC) in more than half of suspected urosepsis episodes and provided results faster, with more than 50% of UC reports available within 1 day. Concordant episodes showed shorter BC time-to-positivity and were associated with faster decline of inflammatory markers and better survival.

METHODOLOGY

• Researchers conducted a retrospective analysis of 2572 paired UC-BC episodes from hospitalized adults with suspected bacteremia at a tertiary-care laboratory in Austria from 2018 to 2024; adults with paired UC and BC obtained within 5 days were included and defined as a single infection episode.
• Clinical suspicion of urinary tract infection (UTI)-related bloodstream infection was determined by manually reviewing laboratory referral forms for mentions of UTI, sepsis/urosepsis, fever of unknown origin, infection, or documented empirical antimicrobial therapy.
• Episodes were considered concordant when UC and BC shared at least one identical pathogen species.
• Analysis compared pathogen spectra, culture dynamics, antimicrobial susceptibility testing (AST) results, laboratory referral information, inflammatory markers, and survival between concordant and discordant episodes.

TAKEAWAY

• Of 2572 episodes, 1405 (54.6%) were concordant, with UC and BC identifying at least one identical pathogen; UC reports were finalized earlier than BC reports, with 50.4% available within 1 day.
• Concordant episodes showed significantly shorter BC time-to-positivity compared with discordant episodes (7.8 hours vs 14.1 hours; P < .001).
• Concordance was also pathogen-dependent, with classical uropathogens (Escherichia coli, Klebsiella species) and Staphylococcus aureus in UC associated with higher odds of detecting the same pathogen in BC. Among concordant Enterobacterales episodes, UC AST showed high agreement with BC AST.
• Concordant episodes were associated with a faster decline in inflammatory markers and better overall survival.

IN PRACTICE

"[The study] findings support the potential diagnostic and stewardship value of UC in the early management of suspected urosepsis, but prospective validation is required before routine implementation in treatment algorithms," the authors wrote.

SOURCE

The study was led by Philipp Grubwieser, Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria. It was published online on September 3 in the International Journal of Infectious Diseases.

LIMITATIONS

The study's retrospective, lab-based design restricted causal conclusions and may have introduced selection and information biases. Because episodes were identified through paired microbiologic sampling and referral-form data, concordant episodes could not all be assumed to reflect true urinary-source sepsis. Additionally, since isolates were not genotyped, concordance was determined only at the species level.

DISCLOSURES

No specific funding was reported. The authors reported no relevant 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.