# The Role of Routine Surveillance Cultures in Optimising Sepsis Management in High-Risk Patient Groups

## TL;DR

This study shows how routine surveillance cultures can help identify antibiotic-resistant bacteria in high-risk patients, improving sepsis management.

## Contribution

The study demonstrates the differential utility of surveillance cultures by specimen type and clinical setting in guiding antimicrobial therapy.

## Key findings

- Rectal swabs detected 100% of E. coli and K. pneumoniae bloodstream infections in haemato-oncology patients.
- Gram-negative pathogens in haemato-oncology were frequently identified in rectal swabs, while acute care cases showed higher concordance with respiratory samples.
- Multidrug-resistant organism prevalence was 5% in acute care and 6.56% in haemato-oncology settings.

## Abstract

Background: Sepsis remains a leading cause of morbidity and mortality, particularly when caused by multidrug-resistant organisms (MDROs). Early identification of colonising or infecting pathogens may inform initial antimicrobial selection. Surveillance cultures, providing microbiological data prior to infection onset, could guide timely and targeted therapy. This retrospective study analysed routine surveillance culture results from patients with bloodstream infection (BSI) episodes, assessing pathogen prevalence, resistance phenotypes, and concordance with specimen type in haemato-oncology (HO) and acute care (AC) settings. Methods: Data were retrieved from the institutional Laboratory Information System of the Department of Clinical Microbiology and ATB Centre, General University Hospital in Prague, covering 1 January to 31 December 2024. All positive blood cultures containing ESCAPE pathogens (excluding Clostridioides difficile) were reviewed. Corresponding surveillance culture records were analysed to evaluate concordance with subsequent BSI episodes. Results: In 2024, 6046 AC and 7267 HO surveillance cultures were performed; MDRO prevalence was 5% and 6.56%, respectively. ESBL-producing Enterobacterales predominated (AC 86.9%, HO 81.6%). In HO, BSI-causing Gram-negative and Gram-positive pathogens were frequently detected in rectal swabs, whereas in AC, concordance was higher with upper and lower respiratory tract samples. Rectal screening detected 100% of E. coli and K. pneumoniae BSI episodes in HO. Other specimen types showed limited concordance. Conclusions: Surveillance culture utility varies by specimen type and clinical setting. In both HO and AC units, these cultures provided valuable insights into colonisation and resistance patterns, supporting early risk stratification and guiding initial therapy in high-risk patients.