Foley catheters functionalised with a synergistic combination of antibiotics and silver nanoparticles resist biofilm formation.

Foley catheters are inevitable in health care unit. Pathogens colonise and form biofilm on catheter causing catheter-associated urinary tract infection. Therefore, the authors aimed to functionalise catheter to resist biofilm formation. The authors impregnated urinary catheters with a synergistic combination of antibiotics and silver nanoparticles (SNPs) to evaluate antibiofilm efficacy in vitro and in vivo. SNPs were synthesised using Spirulina platensis. Synergy between the SNPs and antibiotics was determined by the checker-board method. In vivo efficacy of the functionalised catheters was assessed in mice. Liver and kidney function tests of mice were performed. The in vitro anti-adherence activity of the functionalised catheters was evaluated after 2 years. Nanoparticle sizes were 42-75 nm. Synergistic activity was observed among SNPs (2 µg/ml), amikacin (6.25 µg/ml), and nitrofurantoin (31.25 µg/ml). In mice, catheters functionalised with combinations of antibiotics and SNPs exhibited no colonisation until Day 14. Blood, liver, and kidney tests were normal. After 2 years, catheters functionalised with antibiotics exhibited 25% inhibition of bacterial adhesion, and catheters functionalised with the nanoparticle-antibiotic combination exhibited 90% inhibition. Impregnation of urinary catheters with a synergistic combination of antibiotics and SNPs is an efficient and promising method for preventing biofilm formation.