Comparative analysis of urinary antibiograms in community pediatric and geriatric populations in British Columbia, Canada

Background: The Clinical and Laboratory Standards Institute (CLSI) recommends the development of enhanced antibiograms specifically for elderly patients (65 years) to address the needs of long-term care facilities and to account for the anatomical sites from which specimens are collected, thereby facilitating antimicrobial stewardship. Similarly, the Canadian Pediatric Society advocates developing local, age-specific antibiograms to guide antimicrobial selection for targeted infections. Objective: This study aimed to develop antibiograms based on uropathogens identified at LifeLabs in British Columbia (BC), Canada. Methods: Urinary specimens from pediatric (<18 years) and geriatric (65 years) patients were collected and processed at LifeLabs, a community laboratory network comprising 129 collection centers across BC, between October 1, 2023, and September 30, 2024. Urinary antibiograms for both groups were developed in accordance with CLSI guidelines. Results: Among the 13,870 pediatric specimens, the most common uropathogen was Escherichia coli (13.7%), followed by Enterococcus faecalis (2.0%), Proteus mirabilis (1.1%), Streptococcus agalactiae (0.9%), Staphylococcus saprophyticus (0.9%), and Klebsiella pneumoniae (0.5%). Among the 148,480 geriatric specimens, the most common uropathogen was E. coli (17.1%), followed by E. faecalis (3.6%), K. pneumoniae (3.4%), S. agalactiae (2.0%), P. mirabilis (1.3%), and Pseudomonas aeruginosa (0.8%). Among the routine antimicrobials tested, ciprofloxacin consistently demonstrated significantly different susceptibility rates (p<0.05) between the pediatric and geriatric groups: E. faecalis (96.3% vs. 81.4%), E. coli (73.7% vs. 67.3%), and P. mirabilis (92.6% vs. 84.8%). Conclusion: The distribution of common uropathogens and their susceptibilities differed between pediatric and geriatric groups, supporting the need for age-specific antibiograms in community settings. Ciprofloxacin demonstrated lower susceptibility to the predominant uropathogens in elderly patients. Community antimicrobial stewardship teams should acknowledge these differences to better prioritize interventions tailored to each age group.