BACTERIAL BIOFILMS AND THE BIOELECTRIC EFFECT

Bacterial biofilms are acknowledged to be a major factor in problems o f ineffective sterilization often encountered in clinics, hospitals, a nd industrial processes, There have been indications that the addition of a relatively small direct current electric field with the sterilan t used to combat the biofilm greatly increases the efficacy of the ste rilization process. The results of the experiments reported in this pa per support the concept of the ''bioelectric effect'' as reported by J , W. Costerton, E. Ellis, K. Lam, F, Johnson, and A, E. Khoury (Antimi crob. Agents Chemother, 38:2803-2809, 1994). With a current of 1 mA fl owing through the chamber containing the biofilm, an increase in the k illing of the bacteria of about 8 log orders was observed at the end o f 24 h (compared with the control with the same amount of antibacteria l agent but no current). We also confirmed that the current alone does not affect the biofilm and that there appear to be optimum levels of both the current and the sterilant that are needed to obtain the maxim um effect.