Quicolor: A Novel System for Rapid Antibacterial Susceptibility Testing

Abstract

Early determination of antibacterial susceptibility increases the success of therapy, decreases unnecessary use of antibacterials and side effects and lowers the overall healthcare costs. We have evaluated a rapid antibacterial susceptibility test, Quicolor (Salubris Inc., Massachusetts, USA), which is based on a rapid culture medium that indicates growth early by changing its colour. Quicolor proved to be a reliable rapid test for determining antibacterial susceptibility, having an overall agreement of 97.6% with the conventional CLSI disk diffusion susceptibility test results. Between two methods overall agreement was 96.7% for Enterobacteriaceae, 96.8% for staphylococci and 94.2% for non-fermentative bacteria. There was only 0.6% major discrepancy in Enterobacteriaceae, 1.7% in staphylococci and 0.9% in non-fermentative bacteria. Since the test provides results in 3.5-6 h, it can provide the means to choose the right treatment regimen the same day the infectious agent is isolated.