FIGURE 2.

Effects of sub-inhibitory concentrations of mupirocin (1/64–1/8 MIC) on α-toxin activity in high-level mupirocin-resistant MRSA strains. We used Triton X-100 (which causes complete hemolysis) as a positive control and RRBCs with 0.9% NaCl solution as a negative control. The absorbance at 600 nm (A600 nm) of the positive control was set to 100. The α-toxin activity percentage for each experimental group is the ratio of the A600 nm for that group to the A600 nm of the positive control multiplied by 100. All data were calibrated with negative controls. Each test was performed independently in triplicate. Values are means ± SD (three repeated experiments).