Polymicrobial biofilms and catheter-associated UTIs: Emerging clinical challenges and management perspectives

High prevalence of antibiotic resistance in polymicrobial biofilms, a significant contributor to catheter-associated urinary tract infections (CAUTIs), poses a serious challenge to the medical community. Despite advancements in diagnosis, prevention, and treatment, CAUTIs continue to be a major concern. This review examines several factors that influence the formation and persistence of polymicrobial biofilms. These factors include the types of catheters used, the materials they are made from, the dominant bacteria present, interspecies interactions, and various environmental and host-related factors affecting biofilm formation. Conventional management strategies are often limited by biofilm-associated tolerance, recurrent infections, catheter encrustation, and the increasing prevalence of multidrug-resistant microorganisms, highlighting the need for more effective therapeutic approaches. Nanotechnology has emerged as a promising strategy to overcome these limitations through the development of antimicrobial and antifouling catheter coatings, targeted drug delivery systems, and sustained-release nanomaterials that inhibit microbial adhesion and disrupt biofilm formation. This review discusses the mechanisms of polymicrobial biofilm formation, microbial interactions, catheter- and host-related risk factors, and biofilm-mediated antimicrobial resistance. It further summarizes current diagnostic approaches, including microscopy, fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), sequencing technologies, metagenomics, and biosensors, together with recent advances in physical, biological, chemical, and nanotechnology-based prevention and treatment strategies. Finally, the review highlights the major challenges associated with clinical translation, including biofilm-associated resistance, catheter encrustation, nanomaterial safety, coating stability, and regulatory considerations, and discusses future directions for developing multifunctional catheter coatings, smart therapeutic systems, and advanced diagnostic platforms for improved management of polymicrobial CAUTIs.