VIRULENCE TRAITS AND BACTERIAL INTERACTIONS OF THE COMPLEX MICROBIAL POPULATION IN URINARY DOUBLE-J CATHETERS

Juan Vicente Farizano¹Emilia Castagnaro¹Julian Thomas Arroyo-Egea¹Juan Daniel Aparicio²Alicia Cecilia Vallejos¹Elvira Maria Hebert³Lucila Saavedra³Viviana Andrea Rapisarda¹Josefina Villegas¹Mariana Grillo-Puertas^1,4*

• ¹Instituto Superior de Investigaciones Biológicas (INSIBIO), CONICET-UNT, and Instituto de Química Biológica “Dr. Bernabé Bloj”, Facultad de Bioquímica, Química y Farmacia, UNT., Chacabuco 461, T4000ILI- San Miguel de Tucumán, Argentina
• ²Planta Piloto de Procesos Industriales Microbiológicos (PROIMI-CONICET), Tucumán, Argentina
• ³Centro de Referencia para Lactobacilos (CERELA-CONICET), Tucumán, Argentina
• ⁴CCT CONICET Tucuman, Tucuman, Argentina

Indwelling devices like double J stents are used in urological surgery and are often related with high risk of urinary tract infections (UTI) due to biofilm-associated complications. This study characterized 27 clinical bacterial isolates from double J catheters, including Staphylococcus spp., Enterococcus faecalis, Klebsiella pneumoniae, Escherichia coli, and Bacillus spp., to unravel their pathogenic potential.Our findings revealed that strong biofilm producers (E. coli, S. aureus, B. subtilis) exhibited robust extracellular matrix synthesis. Notably, multidrug resistance was observed in E. coli, K. pneumoniae, and E. faecalis. Mixed-culture experiments demonstrated that Bacillus spp., enhanced biofilm formation of uropathogens, suggesting a potential impact in clinical outcomes. The description of a polymicrobial population colonizing double J catheters, conducted in this study, is essential for understanding the complexity and clinical behavior of biofilm-associated infections in medical devices. Also, our results underscore the clinical relevance of underreported genera such as Bacillus, which is frequently dismissed in routine clinical diagnostics.The insights into the interaction mechanisms and survival strategies of several bacterial species colonizing double J catheters would contribute to shift current paradigms in the understanding of catheter-associated infections.