Bacteraemia due to E.coli in urinary tract infections in adults: a prospective epidemiological study following implementation of guidelines in a regional hospital

Several countries have established action plans for antibiotic stewardship programs (ASPs), which recognise the clinical and public health issues of antimicrobial resistance. We evaluated the impact of a multimodal ASP, implemented in 2017 to improve urinary source E.coli bacteraemia in a secondary care hospital in Catalonia, Spain. Prospective, post-intervention, epidemiological study in a single hospital in Catalonia. Patients were included if they were aged ≥ 18 years, were admitted to the hospital for any cause between January 1, 2017 and December 31, 2022, and had urinary-source E.coli bacteraemia. The primary endpoint was adherence to antimicrobial treatment guidelines for urinary-source E.coli bacteraemia. Secondary endpoints included, appropriate antimicrobial treatment use based on in vitro sensitivity; the degree of error in appropriate use of empirical antimicrobial treatments by guideline adherence (yes/no); and the percentage of E. coli antibiotic resistance in these patients. Of the 297 patients with urinary-source E.coli bacteraemia, the majority were female (57.9%), and the mean (SD) age was 79.0 (16.9) years. Most urinary-source E.coli bacteraemias were community-acquired (n = 194, 65.3%) vs. healthcare system- (n = 78, 26.3%) or hospital- (n = 25, 8.4%) acquired. Adherence rates to antimicrobial treatment guidelines were high across all years (91.4%; range 83.0% to 97.8%), as was the appropriateness of use based on in vitro sensitivity (93.0%; range: 89.4% to 97.8%). The degree of error in appropriate use of empirical antimicrobial treatments was 3.0% (range: 0% to 6.5%) when guidelines were followed and 50.0% (33.3% to 66.7%) when guidelines were not followed. The percentage of urinary-source E.coli bacteraemia which were resistant to treatment with quinolones (44.7% vs. 22.4%; p = 0.014) and ESBLs (21.3% vs. 12.2%; p = 0.058) reduced significantly from 2017 to 2022. No cases of carbapenem resistance occurred. This prospective, single centre study reports a high level of appropriate antimicrobial use, based on both guideline recommendations and in vitro sensitivity testing. Our ASP has been applied successfully over 6 years, resulting in improvements in the empirical antimicrobial treatment of urinary-source E.coli bacteraemia, and a reduction in antimicrobial resistance.