Characterization and Antimicrobial Resistance Profile of Prevalent Uropathogens: A Retrospective Analysis in Primary Care in Peru

Bacterial infections are a major cause of morbidity and mortality worldwide. In Peru, antimicrobial consumption and inappropriate prescribing are both common.

The objective of this study was to evaluate the characteristics and antimicrobial resistance profiles of prevalent uropathogens in primary care.

A retrospective cross-sectional analysis was performed using urine culture records processed between 2024 and 2025 from seven primary care facilities in the Callao region, Peru, serving a predominantly urban population with diverse socioeconomic backgrounds. Urine cultures were classified into three categories: susceptible, intermediate, or resistant. Antimicrobial susceptibility testing was interpreted according to disk diffusion breakpoints, following the guidelines of the Clinical and Laboratory Standards Institute (CLSI).

The analysis included 1,685 cases, with a median age of 43 years (Min: 0, Max: 97, Q1: 25, Q3: 59, IQR: 34). Women accounted for 84.9% (n = 1,431) of the study population. Among the samples, 22.1% (n = 372) were positive, of which 89.5% (333/372) occurred in women (p = 0.007). The most frequently isolated species were Escherichia coli (63.4%), Enterococcus spp. (5.9%), and Klebsiella spp. (5.1%). The antimicrobials with the highest susceptibility rates were nitrofurantoin (93.8%) and amikacin (83.4%).

Our findings confirm Escherichia coli as the main uropathogen in primary care and support the use of nitrofurantoin as first-line therapy. The observed resistance patterns highlight the need for careful antibiotic selection.

In primary care, one-fifth of urine samples tested positive for bacterial species. The most frequently isolated pathogens were Escherichia coli, Enterococcus spp., and Klebsiella spp. The agents with the highest susceptibility and lowest resistance rates were nitrofurantoin and amikacin, both of which are available in primary care settings. Periodic surveillance of antimicrobial susceptibility is essential to monitor bacterial resistance patterns.