[Infections of the urinary tract caused by permanent catheterization. Natural history, infective mechanisms and prevention strategies. An overall review based on our clinical experience and research].

Permanent drainage of the urinary tract by catheters or tubes causes bacteriuria. The potential harmful effects of the indwelling catheter's bacteriuria are related to: time since the insertion of the catheter; location of the catheter (urethra, bladder, kidney); catheter composition (latex, silicone, etc.); type of ineffective bacteria and specific pathogenic mechanisms; health status of the urinary tract being drained (prior radiation therapy, tumors, etc.); patient's health status (diabetes, immunodeficiency) and mobility; incidents and manipulations of the catheter, such as obstruction, irrigation, or retrieval. The evaluation of all mentioned factors enables strategies for prevention of septic episodes in relation with indwelling catheters, strategies that can be individualized for greater efficiency. Despite these preventive measures, infections secondary to the indwelling catheter may cause extremely severe septic episodes. Today, the indwelling catheter bacteriuria constitutes the greater source of nosocomial infection and its prevention and treatment a health care action of the highest importance. The study of mechanisms implied in the formation of biofilms, their pathogenic potential and preventive measures have been an attractive field of clinical and experimental research over the last years. The objective of this review is to make a synthesis of the works performed by our group.