Interpretive criteria for testing susceptibility of staphylococci to mupirocin

To determine appropriate mupirocin susceptibility testing interpretive criteria, 177 staphylococci were tested by agar dilution, disk diffusion, and E test. E test was found to be a reliable method for determining susceptibility of staphylococci to mupirocin. The agar dilution and disk diffusion results were plotted on a scattergram, and error rates were calculated. No errors were found with susceptibility breakpoints of less than or equal to 4 mu g/ml (MIC) and greater than or equal to 14 mm (zone diameter).