Biofilms produced by Pseudomonas aeruginosa and by Staphylococcus aureus on model medical devices.

: Polyethylene, teflon, tygon, polypropylene, silicon rubber, and rubber tubes or rings contaminated with Pseudomonas aeruginosa or Staphylococcus aureus were implanted subcutaneously into mice. After 5 days the colony forming units developing on, and attaching to them were determined. The highest numbers of bacteria were observed on rubber and silicon rubber, polyethylene was next in order, while significantly lower values were obtained on teflon and on tygon and polypropylene. Rubber devices were better colonized after heat than after UV sterilization. The number of bacteria rose further, if the already used rubber implant was resterilized, recontaminated and reimplanted. The model seems suitable to test the development of bacterial biofilms on different materials pretreated in different manners.