A Prospective Study of Pathogenesis of Catheter-Associated Urinary Tract Infections

Next-Science: A Novel Antimicrobial Agent that Inhibits Biofilm Development by Escherichia coli Clinical Isolates on Urinary Tract Catheters

“…One of the pathogens that contributes significantly to CAUTI is E. coli [4,5]. In this study and using E. coli strains, we demonstrated the effectiveness of NS in: 1) preventing biofilm development on three different types of urinary catheters ( Figure 1); 2) preventing biofilm development on both sides of a silicone catheter ( Figure 2); and 3) preventing biofilm development by several clinical isolates on a silicone catheter (Figure 3).…”

“…The bacteria utilize the extraluminal route early during the insertion of the catheter [4]. Alternatively, they may utilize this route later as the perineal bacteria ascend along the outer surface of the catheter [5]. The intraluminal route is utilized either when contaminated urine refluxes into the bladder from the collection bag or when a break in the closed drainage system occurs [5].…”

“…The intraluminal route is utilized either when contaminated urine refluxes into the bladder from the collection bag or when a break in the closed drainage system occurs [5]. Most of CAUTI are caused by a single bacterial species (monomicrobial) including Staphylococcus epidermidis, Enterococcus faecalis, E. coli, and Proteus mirabilis [4][5][6]. These bacteria initially colonize the urinary tract catheter.…”

Catheter –Associated Urinary Tract Infection, Management, And Preventions

“…facilitates ascension of uropathogens from the meatus to the bladder the catheter -mucosa interface, provides a pool of organisms in the drainage bag, if the closed system is not maintained. Which can ascendintraluminally to the bladder, compromises complete voiding and constitutes a frequently manipulated foreign body on which pathogens are deposited via the hands of personnel.Indwelling catheter provide a surface for the attachment of host binding receptors that are recognized by bacterial adhesins, thus enhancing microbial adhesion, as well as disrupting the uroepithelial mucosa to expose new binding sites for bacterial adhesions [19].Bacteria attached to the catheter surface form exopolysaccharides that entrap bacteria, which replicate and form microcolonies that mature into biofilms on the inner and outer surfaces of the catheter [19].These biofilms protect uropathogens from antibiotics and the host immune response and facilitate transfer of antibiotic resistant genes [19].Some uropathogens in biofilms,such as Proteus sp., have the ability to hydrolyze urea to free ammonia and rise the urinary pH ,with precipitation of minerals such ashydroxyapatite or struvite creating encrustatation that can block catheter flow [27,19].The source of uropathogens in catheterized patients includes patients' endogenous flora, health care personnel, or inanimate objects [27].Not unexpectedlyuro pathogen virulence determinants such P fimbriae appear to be of less importance in pathogenesis of nosocomial UTIs compared with uncomplicated UTIs [22].Approximately two thirds(79% for gram-positive cocci and 54% gram-neagative bacilli) of the uropathogens causing CAbacteriuria in patients with in dwellimguretheral catheters are extraluminally acquired(ascension along catheteruretheral mucosa interface) and one third are intraluminally acquired ,although in some trials the proportion of strains originating from the drainage bag is much less, Rectal and periuretheral colonization with the infecting strain often precedes CA-bacteriuria, especially in women [28,29].The relative importance of the intraluminal pathway has much to do the frequency with which closed drainage systems are breached, which has been shown to be associated with UTI. The negative impact of the catheter is demonstrated by the finding that despite the continuous drainage of urine through the catheter,in patients with catheter urine colony count as low as 3 to 4 CFU/ml who are not given antibiotics, the level of bacteriuria or candiduriauniformaly rises to greater than 10 5 CFU/ml,within 24 to 48 hours in those who remain catheterized [30].…”

“…While the catheter is in place systemic antibacterial treatment of asymptomatic catheter-associated bacteriuria is not recommended [37,29,38].Because complications of long-term catheterization are primarily infectious in nature, there is a temptation to treat all patients with catheter-associated bacteriuria; such treatment during catheterization is not helpful in eradicating infection for prolonged periods of time and serves only to select populationsof organisms that are resistant to the antibiotics being used.Therefore ,while the catheter is in place, antibiotic treatment is recommended for symptomatic infection(i.e.bacteremia ,pyelonephritis, epididymitis) [37,29,38]. …”