Extracellular vesicles from bacteria and fungi: mechanistic insights and implications for urinary tract infections

Urinary tract infections (UTIs) pose a significant public health challenge, affecting approximately 407 million people worldwide and causing substantial morbidity and approximately 237,000 deaths. Bacteria and fungi represent the most frequent causative microbes, leading to symptoms such as low abdominal pain, fever, frequent urination, hematuria, sepsis, inflammation of the bladder and kidney, and even death. In recent years, extracellular vesicles (EVs) have emerged as critical mediators of UTI pathogenesis. EVs are lipid bilayer nanoscale particles that carry DNA, RNA, enzymes, and other biomolecules. They can facilitate microbial colonization, immune modulation and evasion, tissue invasion, and antimicrobial agent resistance. This review summarizes current knowledge on the role of bacterial and fungal-derived EVs in UTIs, their mechanisms of action, and their potential therapeutic implications.