The antimicrobial efficacy of a new central venous catheter with long-termbroad-spectrum activity

Indwelling vascular catheters are a major cause of nosocomial sepsis. Preve ntion of colonization of polymeric surfaces by continuous release of bacter icidal, highly biocompatible antimicrobials incorporated into polymers has been investigated as a promising new approach. An antimicrobial polyurethan e catheter was investigated by HPLC and various antimicrobial assays. Contr olled drug delivery governed by the physico-chemical mass transfer from the polyurethane bulk provided long-term release of the antimicrobial substanc es from the material to the outer surface and catheter lumen. The in vitro activity of catheters coated with miconazole and rifampicin against 158 cli nical isolates of catheter-associated infections was evaluated. Incubated i n physiological NaCl at 37 degrees C, the half-life of inhibitory activity of catheters coated with miconazole or rifampicin exceeded 3 weeks. In stat ic and dynamic adhesion assays, coated catheters were able to prevent colon ization with Staphylococcus aureus, Staphylococcus epidermidis and enteroco cci. To produce catheters resistant to infection, a potent antimicrobial ef ficacy combined with an excellent biocompatibility over time is needed. The long lasting efficacy of the antimicrobial polyurethane alloy as well as t he increased antifungal activity of miconazole combined with rifampicin may be regarded as a promising improvement for long-term central venous access .