Abstract
Urinary tract infections, as one of the most common infectious diseases, contribute substantially to the global healthcare burden, particularly due to the rising prevalence of resistant bacterial strains such as Klebsiella pneumoniae. Background/Objectives: The aim was to investigate the prevalence of urinary tract infection pathogens among hospitalized patients at Saint Apostol Luka Hospital in Doboj during the period 2021-2023. Methods: This retrospective cross-sectional study was conducted at Saint Apostol Luka Hospital, Doboj, Republic of Srpska, Bosnia and Herzegovina. Data from the Department of Microbiology were analyzed for the period 2021-2023, including patients with positive urine cultures (≥10(3) CFU/mL) of a single uropathogen. Bacterial identification and susceptibility testing were performed according to EUCAST standards, and statistical analysis was carried out using SPSS v24. Results: Escherichia coli was the most frequent isolate (29.2%), followed by Klebsiella spp. (24.2%) and Enterococcus spp. (19.8%). A significant rise in K. pneumoniae prevalence and resistance to multiple antibiotics-including β-lactams, carbapenems, aminoglycosides, and colistin-was observed during the study period. Conclusions: This study revealed that E. coli and Klebsiella spp. were the leading uropathogens, with notable differences in distribution by sex, age, and hospital department. A marked rise in multidrug resistance, particularly among K. pneumoniae, was observed across the study period. These findings underscore the urgent need for continuous surveillance and stronger antimicrobial stewardship to curb resistance trends.