Virulence traits and bacterial interactions within the complex microbial population in urinary double-J catheters.

Indwelling devices, such as double-J stents, are commonly used in urological surgery and are often associated with a high risk of urinary tract infections (UTIs) due to biofilm-related complications. In this study, we characterized 27 clinical bacterial isolates from double-J catheters, including spp., , and spp., to investigate their pathogenic potential. Our findings revealed that strong biofilm producers (, and ) exhibited robust extracellular matrix synthesis. Notably, multidrug resistance was observed in , and . Mixed-culture experiments demonstrated that spp. enhanced the biofilm formation of uropathogens, suggesting a potential impact on clinical outcomes. The characterization of the polymicrobial population colonizing double-J catheters, as conducted in this study, is essential for understanding the complexity and clinical behavior of biofilm-related infections associated with medical devices. Additionally, our results highlight the clinical relevance of underreported genera, such as , which are often overlooked in routine clinical diagnostics. Gaining insights into the interaction mechanisms and survival strategies of several bacterial species colonizing double-J catheters may help shift current paradigms in understanding catheter-related infections.