Relative surface expression of MntC across <i>S. aureus</i> clinical isolates as measured by whole cell ELISA.

<p><i>S. aureus</i> clinical isolates (WT) representing five different clonal complexes and their isogenic <i>mntC</i> mutants (<i>mntC</i>) were grown in TSB-c supplemented with 400 nM MnSO₄, then tested by whole cell ELISA for relative expression of MntC using polyclonal antibodies purified either from naïve rabbits (unshaded bars) or rabbits immunized with purified MntC (shaded bars). Wild-type 8325-4 and its isogenic <i>mntC</i> mutant were evaluated as comparators. Results were plotted following background correction: average background signal (from assays performed without primary naïve rabbit IgG or primary anti-MntC antibodies) were subtracted from the average sample signals from assays performed with primary antibody. Error bars indicate the standard deviation from duplicate samples. Representative data from one of four experiments yielding similar results is shown (see Materials and Methods).