[Electron microscopic study on the surface of long-term indwelling silver-protein-coated urethral catheters (Urotopic Ag Protein)].

In order to determine the bacterial and crystal adherence to long-term indwelling urethral catheters, we performed a scanning electron microscopic study utilizing commercially available silver-protein-coated latex (Urotopic Ag Protein) and silicone urethral catheters that were left in place for over 4 weeks. Microorganisms and crystals frequently were associated with fibrillar materials. On the surface of silicone catheters bacteria often were embedded in the amorphous matrix. In contrast we found no bacteria adhering to the antimicrobial urethral catheter surface coated with silver-protein. Crystal formation was similar in both catheters, but no catheteral obstruction was observed in this study. We suggested that antimicrobial urethral catheter coated with silver-protein is applicable to patients who tend to form encrustations on long-term indwelling catheters.