Epidemiology of Urinary Pathogens and Antibiotic Resistance Trends: A Retrospective Analysis Stratified by Age and Sex from a Large Tertiary Hospital in Saudi Arabia.

BACKGROUND

Urinary tract infections (UTIs) are among the most prevalent bacterial infections worldwide, with notable variations in antimicrobial resistance (AMR) patterns influenced by age and sex. Local surveillance of resistance trends is essential for optimizing empirical treatment.

METHODS

This retrospective study analyzed urine culture data collected over a span of 7-year (2017-2023) from a tertiary hospital in Saudi Arabia. The distribution of Pathogens and patterns of AMR were examined based on sex, age group, and year. Logistic regression was used to assess predictors of resistance.

RESULTS

The analysis included 3,201 urinary isolates from patients with culture-confirmed UTIs. E.coli was the predominant pathogen in most years, reaching up to 47.5%, but noted a decline in 2020 to 22.7% and further to 22% in 2023. In contrast, K. pneumoniae exhibited steady increase, peaking at 43.1% in 2023. The prevalence of antibiotic resistance to E coli was notably higher among older males (>19 years), with exception of nitrofurantoin in younger males and ampicillin, ciprofloxacin, and sulfamethoxazole-trimethoprim in younger females (≤18 years). In K. pneumoniae, younger males exhibited increased resistance to ampicillin, amoxicillin, and 3rd-generation cephalosporins, while females showed overall higher resistance levels, with the exception of ampicillin and nitrofurantoin, where younger females showed greater resistance. Male sex was significantly associated with resistance in E. coli to ampicillin (OR: 1.53, p=0.021), ciprofloxacin (OR: 1.47, p=0.026), imipenem (OR: 5.83, p=0.009), and in K. pneumoniae to gentamicin (OR: 1.85, p=0.001), ceftriaxone (OR: 2.44, p=0.008), ceftazidime (OR: 1.64, p=0.006), and imipenem (OR: 1.95, p=0.001). Age was inversely associated with imipenem resistance in E.coli (OR: 0.97, p=0.007).

CONCLUSION

This study demonstrates significant variability in UTI pathogens and their resistance patterns based on sex and age. The findings support the need for targeted empirical treatment protocols and underscore the importance of ongoing monitoring of AMR.