Silver or Nitrofurazone Impregnation of Urinary Catheters Has a Minimal Effect on Uropathogen Adherence

Abstract

Purpose-Bacterial adherence to the urinary catheter is an early step in biofilm formation and the pathogenesis of catheter associated urinary tract infection. We studied in vitro the effect of silver or nitrofurazone impregnation of urinary catheters on uropathogen ability to adhere to urinary catheters.Materials and Methods-We studied commercially available nitrofurazone-silicone, silicone only, silver-silicone-hydrogel, silicone-hydrogel, silver-latex-hydrogel and latex-hydrogel catheters. Catheters were incubated in sterile broth for 0, 3, 5, 7 and 10 days, respectively, before inoculation and overnight incubation with Escherichia coli or Enterococcus faecalis.Results-Adherence of E. coli and E. faecalis to nitrofurazone catheters was significantly decreased compared to that of silicone-only catheters when catheters were fresh. The antiadherence effect of nitrofurazone on E. coli decreased with time but was still significant at 5 days. For E. faecalis the effect of nitrofurazone was lost by 3 days of pre-incubation. E. coli adherence was not significantly decreased on silver impregnated catheters compared to that on control catheters of the same base material. Silver was associated with a significant decrease in E. faecalis adherence to latex-hydrogel catheters but not to silicone-hydrogel catheters. The adherence of each species to silicone catheters with hydrogel was significantly lower than that to silicone-only control catheters.Conclusions-Silver impregnation had little effect on bacterial adherence in our model and nitrofurazone impregnation had a significant effect only for the first 5 days. Our results do not support a role for silver urinary catheters to prevent catheter associated urinary tract infection by decreasing bacterial adherence.

Hydrogel Antimicrobial Capture Coatings for Endotracheal Tubes: A Pharmaceutical Strategy Designed to Prevent Ventilator-Associated Pneumonia

“…concluded that impregnation of catheters with silver or nitrofurazone did not significantly affect bacterial adherence in comparison to control catheters 19 . Whilst the evidence generally confirms the affirmative role of local antimicrobial delivery, it is appreciated that the delivery of the antimicrobial agent from such coatings is not fully understood nor optimised, particularly within the respiratory environment in which the volume of fluid for drug elution is limited.…”

Silver Oxynitrate, an Unexplored Silver Compound with Antimicrobial and Antibiofilm Activity

“…Again, Ag 7 NO 11 had a low MBC against planktonic populations, prevented biofilm formation, and eradicated established biofilms at lower concentrations than those of AgNO 3 and CuSO 4 . Certainly, Ag has been explored as a strategy to control infection by uropathogens (72) as well as to combat and control antibioticresistant pathogens, including MRSA (67,(73)(74)(75)(76). The results from this study demonstrated variable sensitivities of the planktonic and biofilm populations to CuSO 4 , AgNO 3 , and Ag 7 NO 11 .…”

Magnetic Particle Induction and Its Importance in Biofilm Research

“…One review (Schumm & Lam, 2008) concluded that silver alloy catheters did decrease the occurrence of asymptomatic bacteriuria in patients undergoing both short term and long term catheterisation, although this decrease was less pronounced in those patients catheterised for over a week. Desai et al (2010) found that nitrofurazoneimpregnated catheters had only a minimal preventative effect in the earlier stages of E.coli and E.faecalis biofilm development (< 5 days) and that silver impregnation had a negligible effect. The incorporation of a silver releasing device between the drainage tube and catheter was found to provide an antibacterial barrier that could protect against bacterial colonisation for periods of at least 10 days in the bag and 8 days for the tubes and catheters (Stickler et al, 1994).…”

“…The adhesion of microorganisms to urinary catheters is particularly problematic. Catheter associated urinary tract infections (CAUTI) are the most common hospital acquired infection (Desai et al, 2010). Urinary catheters are tubular, latex or silicon devices inserted into the bladder via the urethra for a variety of purposes including collection of urine during surgery, measuring urine output, prevention of urine retention and control of urinary incontinence (Schumm & Lam, 2008).…”