Better Use of Existing Antimicrobials

BETTER USE OF EXISTING ANTIMICROBIALS

Although all existing antimicrobials were selected for their efficacy against planktonic cultures and this efficacy has not always translated to activity against biofilms, it may still be possible to make better use of existing anti-microbials to treat biofilm disease. A marked trend in treating chronic infections of many kinds is the use of antibiotic combinations. The possible existence of synergies between existing anti-microbials represents one area of progress in treating biofilm infections. Rational approaches to the application of combinations of anti-microbials, based on the differences of their targets, have not provided clear use predictions. Most combinations are still empirically derived from past experience. The bioFILM PA assay used to select combinations of antibiotics for the treatment of Ps. aeruginosa lung infections in cystic fibrosis patients is one of the first diagnostics to receive regulatory approval (in Canada) and has had a measure of success in the treatment of seriously ill patients. This test is now in clinical trials as a standard diagnostic in cystic fibrosis. Based on the Calgary Biofilm Device, which is the only high through put device for selecting anti-microbials with efficacy against biofilms, this represents one of the first attempts to address the differences in susceptibility of organisms in the biofilm growth mode.