Fig 3.

S. aureus culture supernatant assays. Cell-free culture supernatants of characterized Staphylococcus aureus strains were tested in multiplex assays for SEB, SEC, and TSST to determine assay sensitivity and specificity. The top panels show a multiplex reaction for SEB using the indicated immobilized reagents and an anti-SEB polyclonal detection agent. The middle panels show a multiplex reaction for SEC using the indicated immobilized reagents and an anti-SEC polyclonal detection agent. The bottom panels show a multiplex reaction for TSST-1 using the indicated immobilized reagents and an anti-TSST-1 polyclonal detection agent. The strains tested are indicated at the bottom right. The first panel shows a multiplex reaction for SEB. The bead set coupled with G5-8 shows a higher level of detection than the polyclonal anti-SEB antibody, with low-level detection with L3. This affinity can be attributed to homology between L3 and SEB. The second panel testing anti-SEC antibody shows a high level of detection using L3 but a very low level of detection with the bead set coupled with anti-SEC antibody. The bead sets coupled with anti-TSST antibody and D10V were highly specific and showed high levels of sensitivity.