Prevalence and risk factors of antibiotic resistance for urinary tract infections in patients presenting to a Belgian tertiary care emergency department: testing the national guidelines against the local setting.

Objectives: Urinary tract infections (UTIs) are an important cause of empiric antibiotic (over)treatment at the emergency department (ED). To enhance empiric antibiotic choices, mapping the national and local microbiology and antimicrobial resistance (AMR) patterns is crucial. This study aims to examine resistance patterns at a Brussels ED and to identify risk factors for AMR to evaluate current treatment guidelines and help combat AMR.

Methods: Adult patients undergoing urinalysis at the ED of a Brussels tertiary care hospital with positive urine cultures were included. Descriptive microbiological mapping of UTI or asymptomatic bacteriuria (ASB) micro-organisms was performed. Potential risk factors of antibiotic resistance in Gram-negative bacteria were assessed by using logistic regression analysis.

Results: Out of 96 patients with Gram-negative bacteria in urinary culture, the predominant uropathogen was Escherichia coli (58.3%), with 8.6% being extended spectrum beta-lactamase (ESBL)-producing strains. Overall, fosfomycin (29.2%) and nitrofurantoin (28.6%) showed the highest resistance rates. Ceftriaxone revealed lower resistance rates (13.1%) compared to ciprofloxacin (17.0%) and cefuroxime (18.4%). Temocillin exhibited the lowest resistance rate (8.2%) especially against ESBLs (0%). Ciprofloxacin resistance increased with age (OR 1.05 [1.01-1.10]) and recurrent UTIs (OR 4.79 [1.18-19.42]). Male gender was associated with higher odds of temocillin resistance (OR 5.79 [1.18-28.34]).

Conclusion: In the studied Belgian ED setting, ceftriaxone seems slightly safer than ciprofloxacin, especially for recurrent UTI patients. However, overall, and especially in patients at risk for ESBL-producing bacteria, temocillin would be an even better choice in our setting. National microbiological data should be reviewed to support recommending temocillin as a first-line antibiotic in patients presenting with upper UTI.