Impact of the COVID-19 pandemic on the distribution and antimicrobial resistance patterns of urinary pathogens: a retrospective analysis from a single tertiary care center

Monitoring antimicrobial resistance in urinary tract infections (UTIs) is essential for guiding empirical treatment. This study aimed to evaluate changes in the distribution of Enterobacterales and their antimicrobial resistance patterns the pre and post COVID-19 period. Urine culture results from adult outpatients and inpatients collected between January 1, 2016, and September 30, 2024, were retrospectively analysed. The period before March 11, 2020, was defined as pre-COVID-19, and the subsequent period as the post-COVID-19 period. Only cultures yielding Enterobacterales were included. Antimicrobial susceptibility testing was performed using the VITEK ® 2 system, and resistance patterns were analysed separately for inpatient and outpatient populations. A total of 13,551 isolates were included. Escherichia coli (84.9%) was the predominant pathogen, followed by Klebsiella spp. (11.0%). Post-COVID-19 period, a significant increase in resistance to β-lactams and fluoroquinolones was observed, particularly among E. coli isolates ( p < 0.005 for most agents). Notably, resistance to carbapenems and β-lactam/β-lactamase inhibitor combinations also increased, including among outpatient isolates. In contrast, resistance to aminoglycosides and trimethoprim sulfamethoxazole remained stable or decreased in the post-COVID-19 period. Nitrofurantoin maintained relatively low resistance rates. Antimicrobial resistance among Enterobacterales causing UTIs increased during the COVID-19 period, particularly against commonly used broad spectrum agents. These findings highlight the importance of continuous local surveillance, optimisation of empirical treatment strategies, and strengthened antimicrobial stewardship and infection control practices in both hospital and community settings.