The effect of EDTA instillations on the rate of development of encrustation and biofilms in Foley catheters.

The aim of this research was to examine whether a daily instillation of tetra sodium ethylenediaminetetraacetic acid (EDTA) solution could reduce the rate at which encrustation by crystalline Proteus mirabilis biofilms blocks urinary catheters. Sets of three bladder models were fitted with size 14 all-silicone catheters. Tetra sodium EDTA solution was instilled into the catheter following biofilm development.

Role of swarming in the formation of crystalline Proteus mirabilis biofilms on urinary catheters.

The care of many patients undergoing long-term bladder catheterization is frequently complicated by infection with Proteus mirabilis. These organisms colonize the catheter, forming surface biofilm communities, and their urease activity generates alkaline conditions under which crystals of magnesium ammonium phosphate and calcium phosphate are formed and become trapped in the biofilm. As the biofilm develops it obstructs the flow of urine through the catheter, causing either incontinence due to leakage of urine around the catheter or retention of urine in the bladder.

Does the valve regulated release of urine from the bladder decrease encrustation and blockage of indwelling catheters by crystalline proteus mirabilis biofilms?

Purpose: We tested whether valve regulated, intermittent flow of urine from catheterized bladders decreases catheter encrustation.

Materials And Methods: Laboratory models of the catheterized bladder were infected with Proteus mirabilis. Urine was allowed to drain continuously through the catheters or regulated by valves to drain intermittently at predetermined intervals.

Genotyping demonstrates that the strains of Proteus mirabilis from bladder stones and catheter encrustations of patients undergoing long-term bladder catheterization are identical.

Purpose: We established the incidence of bladder stones in patients who experienced recurrent encrustation and blockage of indwelling bladder catheters and examined the relationship between isolates of Proteus mirabilis from the stones and from the crystalline biofilms on the catheters.

Materials And Methods: The first 100 patients attending a clinic for patients experiencing problems with the management of long-term bladder catheters were studied. Flexible cystoscopy was used to detect bladder stones.

Molecular epidemiology of Proteus mirabilis infections of the catheterized urinary tract.

Proteus mirabilis compromises the care of many patients undergoing long-term indwelling bladder catheterization. It forms crystalline bacterial biofilms in catheters which block the flow of urine, causing either incontinence due to leakage or painful distention of the bladder due to urinary retention. If it is not dealt with, catheter blockage can lead to pyelonephritis and septicemia.

Why are Foley catheters so vulnerable to encrustation and blockage by crystalline bacterial biofilm?

Many patients undergoing long-term bladder catheterisation experience blockage and encrustation of their catheters. The problem stems from infection by urease producing bacteria, particularly Proteus mirabilis. Bacterial biofilms colonise the catheters, the activity of urease raises the pH and induces the deposition of calcium and magnesium phosphate crystals.

The migration of Proteus mirabilis and other urinary tract pathogens over Foley catheters.

Objective: To examine the ability of organisms that infect the catheterized urinary tract to migrate over the surfaces of Foley catheters.

Materials And Methods: In a simple laboratory model, organisms were challenged to migrate across sections of hydrogel-coated latex, hydrogel/silver-coated latex, silicone-coated latex and all-silicone catheters. The sections (1 cm long) were placed as bridges in channels between blocks of agar and the test organisms inoculated onto the agar adjacent to one side of each bridge.

Studies on the formation of crystalline bacterial biofilms on urethral catheters.

A model of the catheterised bladder was used to test the ability of urease-producing urinary tract pathogens to encrust urethral catheters. Encrustation was assessed by determining the amounts of calcium and magnesium deposited on the catheters and visualised by scanning electron microscopy. Urease-positive Morganella morganii, Klebsiella pneumoniae, and Pseudomonas aeruginosa failed to raise the urinary pH and form crystalline biofilms.