An antimicrobial modified silicone peritoneal catheter with activity against both Gram positive and Gram negative bacteria

Peritonitis, exit site and tunnel infections are serious complications of peritoneal dialysis (CAPD), which may lead to catheter loss, despite measures taken to reduce the infection rate. Catheters coated with antimicrobials have shown only short-term activity. We have developed a process for conferring broad-spectrum, long-duration antimicrobial activity on CAPD catheters while reducing the risk of resistance. Catheters were processed using an impregnation method. Three agents were used: rifampicin, triclosan and trimethoprim. Tests included establishing the duration of activity before test bacteria became resistant, the ability to kill 100% of attached bacteria in a predetermined time (tK100), and ability to withstand multiple high-count challenges until failure in a flow model. Antimicrobial activity continued until it was stopped at 280 days and the agents prevented the emergence of resistant strains. tK100 results showed a >99.9% reduction of attached bacteria. The flow model showed no colonization when repeatedly challenged with high loads of meticillin-resistant Staphylococcus aureus or Escherichia coli for ∼90 days. The antimicrobial catheter material showed prolonged activity against common CAPD pathogens and promises to reduce clinical CAPD infection.