A model of catheter colonisation in vitro and its relationship to clinical catheter infections.

A laboratory model for colonisation of silicone-rubber catheters by staphylococci is described. The criteria for true colonisation that involves adhesion of the organisms to the luminal surface are discussed. Light and scanning electron micrographs of the microcolonies produced in the laboratory model suggest that the same mechanisms of adhesion, involving extracellular slime, apply as in clinically colonised catheters. Potential uses of the model, for studying further the mechanisms of colonisation and particularly its prevention and treatment, are discussed.