Iontophoretic killing of Escherichia coli in static fluid and in a model catheter system

Abstract

A static iontophoretic model system was used to determine the effects of various metals, .mu.A levels and voltage levels on E. coli and several other bacterial genera. Only Au iontophoresis at 400 .mu.A and .apprx. 3.2 V was found to kill all bacterial genera tested when the inoculum dose was 1 .times. 103 cells per ml. E. coli was killed at all inocula doses to 1 .times. 107, whereas other genera were inhibited. Other metals, such as Ag or Cu, were not effective in killing bacteria. A model catheter system, which contained a Au iontophoresis device, was used to kill E. coli in a flowing system at sites as far as 10 cm downstream from the iontophoretic device. The experiments suggest Au iontophoresis can be a potential tool in controlling catheter-related infections.