Which indwelling urethral catheters resist encrustation by Proteus mirabilis biofilms?

Abstract

Objective To test the resistance of currently available types of indwelling urethral catheters to blockage by encrustation with mineralized Proteus mirabilis biofilms. Materials and methods Encrustation was studied in a simple laboratory model of the catheterized bladder. Artificial urine was supplied to the bladder chamber at 0.5 mL/min. The bladder urine was inoculated with a clinical strain of P. mirabilis that had been isolated from an encrusted catheter. The models were operated until the catheters blocked and atomic absorption spectrometry was used to assess the amounts of calcium and magnesium deposited on the catheters. Scanning electron microscopy was also used to locate and assess the degree of encrustation. Results The mean times to blockage ranged from 21 h for the Bard hydrogel/silver‐coated latex catheter to 56 h for the Eschmann Folatex S all‐silicone catheter. The calcium and magnesium salts were mainly deposited on the 10 cm below the eye‐holes of the catheters, complete blockage generally occurring in the 2 cm immediately below the eye‐hole. Conclusion None of the 18 types of catheter tested, including those coated with hydrogel or silver, were capable of resisting encrustation by P. mirabilis biofilm.

Modulation of crystalline Proteus mirabilis biofilm development on urinary catheters

“…The composition of the basic artificial urine that has been used in our previous studies (Morris et al, 1997) on the formation of crystalline biofilm in the bladder model was devised to simulate the urine produced from elderly longterm catheter users who commonly drink very little. In models supplied with this concentrated urine, encrustation forms rapidly and the catheters block in 19-31 h. Patients are often encouraged to increase their fluid intake by nursing staff, but it is difficult to persuade them to take more fluids.…”

“…Reflux of infected urine to the kidneys can then precipitate serious symptomatic episodes such as pyelonephritis, septicaemia and endotoxic shock (Kunin, 1997). All available types of indwelling catheter are vulnerable to this problem (Morris et al, 1997) and currently there are no effective procedures available for its control (Kunin, 1997).…”

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

“…mirabilis is an ingenious organism that can initiate the formation of crystalline biofilms in several ways 24 on all types of indwelling catheters including those with silver and nitrofurazone coatings. 4,25 To deal with the complication more effectively, it is important to understand the precise mechanisms P. mirabilis uses to colonize, encrust and block catheters. The primary stage in the formation of biofilms on implanted medical devices usually involves their rapid coating by a conditioning film of proteins from body fluids.…”

“…1,2 All available catheter types are vulnerable to this problem and currently no effective methods are available for its prevention or control. [3][4][5] In many cases, the replacement catheters block repeatedly and the patients are classified as 'blockers'. 6 Up to 50% of the patients undergoing long-term catheterization will experience catheter encrustation and blockage.…”

Formação de biofilme cristalino de Proteus mirabilis em cateter urológico

“…Nos últimos 60 anos as características do cateter de Foley pouco mudaram e tentativas têm sido feitas para prevenir a infecção bacteriana e reduzir a incrustação (Morris et al, 1997). A implementação do sistema fechado de drenagem (Saint e Lipsky, 1999) diminuiu a infecção bacteriana de 97% para 15% (Winn, 1996).…”