The encrustation and blockage of long-term indwelling bladder catheters: a way forward in prevention and control

Abstract

Objectives: To review the literature showing that understanding how Foley catheters become encrusted and blocked by crystalline bacterial biofilms has led to strategies for the control of this complication in the care of patients undergoing long-term indwelling bladder catheterization. Methods: A comprehensive PubMed search of the literature published between 1980 and December 2009 was made for relevant articles using the Medical Subject Heading terms 'biofilms', 'urinary catheterization', 'catheter-associated urinary tract infection' and 'urolithiasis'. Papers on catheterassociated urinary tract infections and bacterial biofilms collected during 40 years of working in the field were also reviewed. Results: There is strong experimental and epidemiological evidence that infection by Proteus mirabilis is the main cause of the crystalline biofilms that encrust and block Foley catheters. The ability of P. mirabilis to generate alkaline urine and to colonize all available types of indwelling catheters allows it to take up stable residence in the catheterized tract in bladder stones and cause recurrent catheter blockage. Conclusion: The elimination of P. mirabilis by antibiotic therapy as soon as it appears in the catheterized urinary tract could improve the quality of life for many patients and reduce the current expenditure of resources when managing the complications of catheter encrustation and blockage. For patients who are already chronic blockers and stone formers, antibiotic treatment is unlikely to be effective owing to the resistance of cells in the crystalline biofilms. Strategies such as increasing fluid intake with citrated drinks could control the problem until bladder stone removal can be organized.

Impact of the lack of community urinary catheter care services on the Emergency Department

“…Most importantly, we need to establish the causes for blocked catheters, including the characteristic pattern of catheter life in these patients. Catheters could be scheduled to be replaced before becoming a clinical crisis [24], which concurs with NICE recommendations.…”

Type 1 Fimbriae Contribute to Catheter-Associated Urinary Tract Infections Caused by Escherichia coli

“…Sterile urine is supplied into the bladder with a peristaltic pump throughout the experiment at a physiologically relevant rate. This system was used extensively to study catheter encrustation and blockage in vitro (31) and mirrors the physicochemical parameters of CAUTIs after bladder infection, including the flushing of urine through the catheter, albeit in the absence of a bladder mucosa. For each potential virulence factor, the catheterized bladder model was inoculated with a 1:1 ratio of wild-type to mutant cells.…”

Ureolytic Biomineralization Reduces Proteus mirabilis Biofilm Susceptibility to Ciprofloxacin

“…This idea was confirmed by clinical evidence showing that most patients with recurrent catheter encrustation had bladder stones that harbored P. mirabilis (47). As an alternative, it has been observed in clinical settings that increased fluid intake can slow the rate of catheter encrustation by diluting salt concentrations in the urine (48). Our results further suggest that reducing biomineralization would render biofilms more susceptible to killing, indicating that control of catheter encrustation and biofilm formation elsewhere in the urinary tract is critical not only to the longevity of catheters but also to the effectiveness of antimicrobial therapies for CAUTIs.…”