Uncovering the Hidden Diversity and Antimicrobial Resistance of Uropathogens in a Tertiary-Care Hospital in Bangladesh.

Urinary tract infections (UTIs) are among the most common bacterial infections worldwide; however, their diagnosis in low- and middle-income countries often relies on conventional culture and biochemical methods with limited sensitivity. This study evaluated the limitations of routine diagnostic approaches and explored the microbial diversity and antimicrobial resistance (AMR) profiles of uropathogens in a tertiary-care hospital in Bangladesh using integrated culture-based and molecular methods. Among 30 patient urine samples collected in 2025, 10 were selected for detailed analysis due to funding and resource limitations; therefore, the findings should be interpreted as exploratory and may be subject to selection bias. Of these 10 samples, routine hospital diagnostics identified only eight isolates, whereas extended biochemical analysis detected 29 isolates, indicating substantial underestimation of microbial diversity in standard practice. Antibiotic susceptibility testing revealed a high prevalence of multidrug resistance, with 83% and 80% of isolates resistant to ampicillin and clindamycin, respectively. In contrast, nitrofurantoin and fosfomycin retained effectiveness against most isolates, supporting their continued clinical utility. 16S rRNA gene sequencing further revealed complex and heterogeneous microbial communities, with several samples dominated by Escherichia-Shigella, whereas others exhibited polymicrobial profiles including commensal and opportunistic genera. Despite taxonomic variability, microbial diversity did not differ significantly between inpatient and outpatient groups. Functional pathway prediction demonstrated a largely conserved metabolic profile across samples, including pathways associated with virulence, iron acquisition, and AMR. Overall, this study demonstrates that conventional diagnostic methods substantially underestimate uropathogen diversity and may contribute to misdiagnosis and inappropriate antibiotic use. Integrating molecular approaches into routine clinical workflows could improve pathogen detection, enhance AMR surveillance, and support more effective management of UTIs in Bangladesh and similar resource-limited settings.