Catheter-associated urinary tract infections

Abstract

In the past few years it has been clearly demonstrated that the concept of bacterial biofilm production permits an understanding and provides some explanation of the pathogenesis, diagnosis and treatment of catheter-associated urinary tract infections. This concept describes the colonization of catheter surfaces and the movement of bacteria against the urinary flow. It explains the antibacterial resistance of these matrix-enclosed sessile populations of bacteria. The catheter encrustation can be observed as mineralizing bacterial biofilm. The differentiation in swarming cells exposing a much higher activity of the enzyme urease is responsible for the predominant role of Proteus mirabilis in obstructing encrustations. The guidelines for the prevention of catheter-associated urinary tract infections were developed over the past decades by clinicians and are still valid. They can now be better understood taking into consideration these new theories. As overuse of urethral catheters and non-compliance of their recommended use are still apparent, educational and surveillance programmes are needed to help maintain good standards of care.

Observation of Double J Stent Bacterial Colonisation and Its Correlation With Bacteriuria Frequency

“…As overuse of urethral catheters and noncompliance with their recommended use are still apparent, educational and surveillance programs are needed to help maintain good standards of care. [16] Further prospective studies are needed to determine the optimal duration of DJ stent use after different urological approaches. However, we recommend that patients with DJ ureteral stents who can be at risk for bacteraemia be covered by broad-spectrum antibiotics, especially if indwelling time is more than 6 weeks and that the stents should be kept indwelling for the shortest possible time.…”

Biofilm and Urogenital Infections

“…Extraluminal organisms are primarily endogenous, originating from the gastrointestinal tract. These organisms colonize the patient's perineum and ascend the urethra after catheter insertion [13,31,32,33,34] Approximately 70% of bacteriuria in catheterized women is believed to occur through the extraluminal entry. Bacteria can ascend the catheter also by an intraluminal route, which occurs when organisms gain access to the internal lumen of the catheter.…”

“…Bacteria can ascend the catheter also by an intraluminal route, which occurs when organisms gain access to the internal lumen of the catheter. These organisms are usually introduced from exogenous sources, for instance with cross transmission from the hands of health care personnel [13,32,33,35]. Adhesion of microorganisms to catheter materials depends on the hydrophobicity of the organism and catheter surface.…”

Catheters and Infections

“…The mechanism is therefore strictly related to the adhesion of bacteria to the bladder during catheterization. Analysis with electron microscope of the surface of catheters show that indwelling catheters are rapidly colonized by a thick layer of microorganisms included in a protein matrix of the host, and by polysaccharides produced by bacteria that form a biofilm (20). The risk of urinary tract infection is related to the length of time that the catheter is in place.…”

“…Biofilms containing 5 × 109 viable cells per centimeter can be found on long-term indwelling catheters removed from patients. (20) The biofilm populations, therefore are often outnumber than those in the urine. The most common species present in the mixed-population biofilms are E. faecalis, P. aeruginosa, E. coli, and P. mirabilis.…”